Document:

<Page>
                                                                   Exhibit 10.20

  "Pages where confidential treatment has been requested are marked
  'Confidential Treatment Requested.' The redacted material has been
  separately filed with the Commission, and the appropriate section has been
  marked at the appropriate place and in the margin with a star (*)."

CEDAR BAYOU FRACTIONATORS, L.P.
1000 Louisiana, Suite 5800
Houston, Texas 77002
Phone 713.507.6400

                                       December 23, 1998

Mr. Steven J. Malcolm
Senior Vice President and General Manager
Williams Midstream Natural Gas Liquids, Inc.
P.O. Box 3102
Tulsa, Oklahoma 74101

             RE:   Option To Acquire Interest In Cedar Bayou Fractionators, L.P.

Dear Mr. Malcolm:

      This letter agreement ("Letter Agreement") sets forth certain terms and
conditions between Williams Midstream Natural Gas Liquids, Inc. ("Williams")
and Cedar Bayou Fractionators, L.P. ("CBF") regarding an option hereby
granted by CBF in favor of Williams, or any affiliate transferee of Williams,
to acquire an ownership interest in Cedar Bayou Fractionators, L.P. ("CBF").
This Letter Agreement is being entered into contemporaneously with that
certain Fractionation Agreement between CBF and Williams Energy Marketing &
Trading Company (the "Fractionation Agreement"). If prior to the exercise of
the Option granted herein, the Fractionation Agreement terminates for any
reason whatsoever, the Option granted' herein shall likewise IPSO FACTO
terminate.

      1.    During the period from January 1, 2001, to October 1, 2004, Williams
            shall have the right and option (the "Option") to earn a five
            percent (5%) limited partnership interest in CBF in exchange for the
            contribution to CBF of an agreement to fractionate raw product
            containing an Option Dedication as set forth in Paragraph 2 below.
            To exercise such Option, Williams must notify CBF in writing of its
            election to exercise the Option at least one hundred twenty (120)
            Days prior to the date that Williams desires its ownership in CBF to
            be effective. The effective date of Williams' ownership interest in
            CBF shall be the first day of the Month immediately following the
            commencement of deliveries to CBF under the Option Dedication.

      2.    In order to exercise the Option granted herein, Williams must assign
            to CBF an agreement to fractionate raw product containing (i)
            substantially the same terms and conditions as the fractionation
            agreements that Amoco Oil Company and Warren Gas Liquids, Inc., as
            affiliates of the existing partners in CBF, entered into with CBF
            effective January 1, 1998, (collectively the "Owners' Fractionation
            Agreements") and (ii) a dedication for fractionation at the CBF
            Fractionator

<Page>

                          'Confidential Treatment Requested'

  Williams Midstream Natural Gas Liquids, Inc.
  December 23, 1998
  Page 2

            situated in Mont Belvieu, Texas, of Raw Product volumes produced
            from one or more of the sources listed in Exhibit "A" to the
            Fractionation Agreement (the "Option Dedication"). The volumes of
            Raw Product produced from the sources included in the Option
*           Dedication must be projected to average at least [REDACTED] Barrels
            per Day through December 31, 2008, based on (i) the gas committed to
            such facilities during such time period and (ii) good faith
            estimates of the reserves attributable to leases and/or wells
            dedicated for processing at such facilities during such time period
            (for the period of such dedications) as certified to by an officer
            of Williams at the time the Option is exercised. The parties hereto
            acknowledge that the Owners' Fractionation Agreements with CBF
            provide that their respective fractionation fees can be
            re-determined if requested by such Owner at least ninety (90) days
            prior to, but no more than one hundred fifty days (150) prior to,
            January 1, 2003 (such re-determined fees to be effective January 1,
            2003), and every five (5) years thereafter. The parties further
            acknowledge that the price re-determination procedure is based on:
            first, negotiation between the parties to the agreements for sixty
            (60) days after the receipt of the initiating party's notice; and,
            second, if no price is agreed to through such negotiation, by
            "baseball" style arbitration whereby the arbitrator's decision shall
            be required to be based on a determination of which of the parties'
            final offers most closely approximates the then current fair market
            rate for the fractionation and other services provided by CBF
            thereunder, based on a five year term for volumes and composition of
            raw product similar to that then being tendered by the customer
            under that fractionation agreement and with the market area for
            comparison being the "Mont Belvieu Area," as defined in the Owners'
            Fractionation Agreements. Williams shall have the right to cause the
            fractionation fees it is to pay under the Option Dedication to be
            re-determined by notifying CBF no more than one hundred fifty (150)
            days no later than ninety (90) days prior to January 1, 2003, of (i)
            its election to exercise the Option granted herein and (ii) its
            request to re-determine the fractionation fees it is to pay under
            the Option Dedication, even though the Option Dedication has not yet
            been evidenced in a fractionation agreement or is yet effective.

            3.  Additionally, as further conditions to its exercise of the
                Option granted herein, upon such exercise, Williams agrees:

                a.   upon the CBF partners' reasonable grounds for insecurity
                concerning the financial ability of Williams, or any affiliate
                transferee of Williams, to perform its obligations as a limited
                partner of CBF, to deliver a mutually-acceptable parent guaranty
                of such obligations either by Williams' ultimate parent company
                or a Williams' affiliate acceptable to the CBF partners and
                containing terms and conditions that are essentially similar in
                all material respects to the parent

<Page>

Williams Midstream Natural Gas Liquids, Inc.
December 23, 1998
Page 3

                guaranty (currently in effect) supporting Amoco MB Fractionation
                Company's obligations as a limited partner in CBF; and

                b.   agree in writing to be bound by the then current terms of
                the Limited Partnership Agreement governing CBF and to assume
                all obligations, liabilities and duties with respect to the
                percentage of partnership interest acquired by exercise of the
                Option granted herein.

      Amoco MB Fractionation Company, Dynegy Midstream Services, Limited
Partnership and Downstream Energy Ventures Co., L.L.C. each intervene herein
and are executing this Letter Agreement solely for the purpose of (i)
acknowledging the right of Williams to acquire an ownership interest in CBF
in accordance with the provisions of this Letter Agreement, (ii) consenting
to such acquisition by Williams and (iii) waiving any rights (preferential or
otherwise) that they may have to acquire such ownership interest in CBF.

      If the foregoing represents your understanding of our agreement, please
so indicate by signing the two originals of this Letter Agreement in the
appropriate spaces and returning one fully executed original to me. This
letter agreement may be executed in multiple counterparts.

AGREED TO AND ACCEPTED THIS 23RD DAY
OF DECEMBER, 1998:

CEDAR BAYOU FRACTIONATORS, L.P.
BY:   Downstream Energy Ventures Co., L.L.C.
      its Managing General Partner

By:  /s/  TERRY D. JONES
--------------------------------------------
Printed Name:  Terry D. Jones
               -----------------------------
Title:  Vice President
      --------------------------------------

AGREED TO AND ACCEPTED THIS 23RD DAY
OF DECEMBER, 1998:

WILLIAMS MIDSTREAM NATURAL GAS
LIQUIDS, INC.

By:  /s/  STEVEN MALCOLM
--------------------------------------------
Printed Name:  Steven Malcolm
            --------------------------------
Title:         President
      --------------------------------------

<Page>

Williams Midstream Natural Gas Liquids, Inc.
December 23, 1998
Page 4

APPROVED AND JOINED IN BY THE FOLLOWING INTERVENORS IN THEIR CAPACITY OF
PARTNERS IN CEDAR BAYOU FRACTIONATORS, L.P. FOR THE LIMITED PURPOSES STATED
ABOVE,

Dynegy Midstream Services, LIMITED Partnership, limited partner
      By:   Dynegy Midstream G.P., Inc., general partner

By:  /s/  STEPHEN A. FURBACHER
--------------------------------------------
Printed Name:  Stephen A. Furbacher
            --------------------------------
Title:  PRESIDENT
     ---------------------------------------

Amoco MB Fractionation Company, limited partner

By:  /s/  A.B. ANDERSON
--------------------------------------------
Printed Name:  A.B. Anderson
            --------------------------------
Title:  President
     ---------------------------------------

Downstream Energy Venture Co., L.L.C., Managing General Partner

By:  /s/  WILLIAM E. PUCKETT
--------------------------------------------
Printed Name:  William E. Puckett
            --------------------------------
Title:         Vice President
      --------------------------------------

<Page>

                       'Confidential Treatment Requested'

  DYNEGY MIDSTREAM SERVICES, LIMITED PARTNERSHIP
  1000 Louisiana Street, Suite 5800
  Houston, Texas 77002
  Phone 713.507.6400
  www.dynegy.com

                                December 23, 1998

                                                               [DYNEGY LOGO]

  Mr. Steven J. Malcolm
  Senior Vice President and General Manager
  Williams Midstream Natural Gas Liquids, Inc.
  P. 0. Box 3102
  Tulsa, Oklahoma 74101

             RE:   Option To Acquire Interest In Cedar Bayou Fractionators, L.P.

  Dear Mr. Malcolm:

      This letter agreement ("Letter Agreement") sets forth certain terms and
  conditions between Williams Midstream Natural Gas Liquids, Inc. ("Williams")
  and Dynegy Midstream Services, Limited Partnership ("Dynegy") regarding an
  option hereby granted by Dynegy in favor of Williams, or any affiliate
  transferee of Williams, to acquire a portion of Dynegy's ownership interest
  in Cedar Bayou Fractionators, L.P. ("CBF"), the owner of the fractionator
  situated in Mont Belvieu, Texas, previously owned by Dynegy (the
  "Fractionator"). This Letter Agreement is being entered into
  contemporaneously with that certain Fractionation Agreement between CBF and
  Williams Energy Marketing & Trading Company (the "Fractionation Agreement").
  If prior to the exercise of the Option granted herein, the Fractionation
  Agreement terminates for any reason whatsoever, the Option granted herein
  shall likewise IPSO FACTO terminate.

      During the period from January 1, 2001, to October 1, 2004, Williams
  shall have the right to acquire a portion of Dynegy's limited partnership
  interest in CBF, at a price set forth as follows. For each one percent of
  such limited partnership interest in CBF acquired from Dynegy pursuant to
* this Option, Williams shall pay to Dynegy (i) the sum of [REDACTED] plus
  (ii) an amount determined by multiplying the additional ownership interest
* percentage Williams is electing to acquire times (x) the sum of [REDACTED],
* and (y) the sum of [REDACTED]. The maximum amount of additional ownership
  that Williams will be entitled to acquire under this Option will be the
  lesser of (a) fifteen percent (15%), or (b) a percentage interest calculated
  by dividing the volume of Raw Product delivered to the Fractionator by or on
  behalf of Williams and/or its affiliates during the preceding twelve (12)
  Months by the total volume of NGLs fractionated at the Fractionator during
  the same time period, and then subtracting from this quotient any additional
  ownership interest acquired

<Page>

Williams Midstream Natural Gas Liquids, Inc.
December 23, 1998
Page 2

by Williams and/or its affiliates pursuant to the option granted by CBF to
Williams dated of even date herewith (the "CBF Option"). "Pay-out capital"
shall be defined as capital invested in Fractionator projects netting at
least a demonstrated fifteen percent (15%) after-tax rate of return; or, for
projects netting less than a demonstrated fifteen percent (15%) after-tax
rate of return, that portion of capital invested in such projects that would
result in an equivalent fifteen (15%) after-tax rate of return. The
after-tax rate of return will be calculated using the criteria described in
Exhibit "A" which is attached.

To the extent feasible without limiting the benefits to Williams of the
Option granted herein, the parties agree that they will cooperate to
structure any acquisition of ownership interests in CBF by Williams in the
most tax efficient manner reasonably achievable.

As conditions to its exercise of the Option granted herein, upon such
exercise, Williams agrees:

         a.   upon the CBF partners' reasonable grounds for insecurity
         concerning the financial ability of Williams, or any affiliate
         transferee of Williams, to perform its obligations as a limited
         partner of CBF, to deliver a mutually-acceptable parent guaranty of
         such obligations either by Williams' ultimate parent company or a
         Williams' affiliate acceptable to the CBF partners and containing
         terms and conditions that are essentially similar in all material
         respects to the parent guaranty (currently in effect) supporting
         Amoco MB Fractionation Company's obligations as a limited partner in
         CBF; and

         b.   to agree in writing to be bound by the then current terms of the
         Limited Partnership Agreement governing CBF, and to assume all
         obligations, liabilities and duties with respect to the percentage
         of ownership interests acquired by Williams by exercise of the
         Option granted herein.

      Amoco MB Fractionation Company and Downstream Energy Ventures Co.,
L.L.C. each intervene herein and are executing this Letter Agreement solely
for the purpose of (i) consenting to the acquisition by Williams of a portion
of Dynegy's ownership interest in CBF in accordance with the provisions of
this Letter Agreement and (ii) waiving any rights (preferential or otherwise)
that said entities may have to acquire such ownership interest in CBF.

      Dynegy warrants that it has all necessary authority to enter into this
agreement and that it will maintain sufficient equity interest in CBF to
allow Williams to exercise the options granted herein in accordance with
their terms.

      If the foregoing represents your understanding of our agreement, please
so indicate by signing the two originals of this Letter Agreement in the
appropriate spaces and returning one fully executed original to me. This
letter agreement may be executed in multiple counterparts.

<Page>

Williams Midstream Natural Gas Liquids, Inc.
December 23, 1998
Page 3

AGREED TO AND ACCEPTED THIS 23RD DAY
OF DECEMBER, 1998:

DYNEGY MIDSTREAM SERVICES, LIMITED PARTNERSHIP
By: Dynegy Midstream G.P., Inc., its General Partner

By: /s/  STEPHEN A. FURBACHER
--------------------------------------------
Printed Name:  Stephen A. Furbacher
             -------------------------------
Title:         PRESIDENT
      --------------------------------------

AGREED TO AND ACCEPTED THIS 23RD DAY
OF DECEMBER, 1998:

WILLIAMS MIDSTREAM NATURAL GAS
LIQUIDS, INC.

By:  /s/  STEVEN MALCOLM
--------------------------------------------
Printed Name:  Steven Malcolm
             -------------------------------
Title:         President
      --------------------------------------

INTERVENORS

ACKNOWLEDGED AND AGREED TO THIS
23RD DAY OF DECEMBER, 1998

Downstream Energy Ventures Co., L.L.C.,
      As General Partner in Cedar Bayou Fractionators, L.P.

By:  /s/  WILLIAM E. PUCKETT
--------------------------------------------
Printed Name:   William E. Puckett
            --------------------------------
Title:          Vice President
     ---------------------------------------

<Page>

Williams Midstream Natural Gas Liquids, Inc.
December 23, 1998
Page 4

Amoco MB Fractionation Company,
      As Limited Partner in Cedar Bayou Fractionators, L.P.

By:  /s/  A.B. ANDERSON
--------------------------------------------
Printed Name:  A.B. Anderson
            --------------------------------
Title: President
      --------------------------------------

<Page>

                                   Exhibit "A"

                                       To
  Dynegy/Williams Option to Acquire Interest in Cedar Bayou Fractionators, L.P.

The following are some of the basic economic evaluation criteria that will be
used to evaluate the after-tax rate of return on "Pay-out capital" projects,
it being understood that the following are intended as guidelines only and
are not exclusive and some may not be appropriate for some projects.

1.    The implicit value of the investment shall be computed using a mid year
      discounted cash flow analysis.

2.    The tax rate shall be the combined federal and state nominal tax rates.
      Applicable state and local ad valorem taxes will be included in the cash
      flow analysis.

3.    Tax depreciation shall be computed using the Federal Tax Code.

4.    The project life shall be the industry standard, not to exceed 20 years.

5.    Debt financing on the project will not be considered. All cash flows shall
      be computed on an unleveraged basis.

6.    Operating and maintenance (O&M) costs will be comparable to similar
      applications within the industry. O&M will be escalated using indices
      cited in the Fractionation Agreement between Williams and CBF.

7.    For capital projects involving plant capacity expansions or plant fuel
      efficiency, revenues shall be incremental to the 1998 capacity of the CBF
      fractionator and the 1998 fuel efficiency of the CBF fractionator.

8.    If available, actual cost will be used for original capital investment
      costs. Otherwise, independent engineering estimates of costs to be spent
      will be used.

9.    The cash flow analysis will include required maintenance capital
      expenditures and related upstream or downstream capital expenditures that
      are necessary for the projects.

10.   The terminal asset value cannot exceed the lesser of: i) the original
      costs; or ii) five (5) times the projects earnings (before interest,
      depreciation and amortization, sometimes referred to as "EBIDA").

11.   The evaluation of a project shall take place at the time that Williams is
      exercising the Option granted in the Letter Agreement to which this
      Exhibit "A" is attached and if actual project performance varies from the
      estimate made at that time, Williams may not thereafter make any claim for
      reimbursement or any amounts paid to Dynegy for an ownership interest in
      reliance on such estimate nor will Dynegy have any right for additional
      payments for a similar reason.<Page>
                                                                   Exhibit 10.21

"Pages where confidential treatment has been requested are marked 'Confidential
Treatment Requested.' The redacted material has been separately filed with the
Commission, and the appropriate section has been marked at the appropriate place
and in the margin with a star (*)."

                          LIMITED PARTNERSHIP AGREEMENT

                                       of

                         CEDAR BAYOU FRACTIONATORS, L.P.

                         A Delaware Limited Partnership

                            Effective January 1, 1998

<Page>

                           LIMITED PARTNERSHIP AGREEMENT
                                        OF
                          CEDAR BAYOU FRACTIONATORS, L.P.

                                 TABLE OF CONTENTS

<Table>
<S>                                                                                          <C>
  1.     PARTNERSHIP FORMATION ...............................................................1
         1.1.   Formation ....................................................................1
         1.2.   Filings and Further Action ...................................................1
         1.3.   Name .........................................................................2
         1.4.   Place of Business; Registered Agent ..........................................2
         1.5.   Purpose ......................................................................2
         1.6.   Term .........................................................................3
         1.7.   Waiver of Right of Partition .................................................3
  2.     DEFINED TERMS .......................................................................3
  3.     INITIAL CAPITAL CONTRIBUTIONS ......................................................10
         3.1.   Warren ......................................................................10
         3.2.   DEVCO .......................................................................10
         3.3.   Amoco .......................................................................10
         3.4.   Default in Making of Initial Capital Contributions ..........................11
         3.5.   Other Remedies ..............................................................11
         3.6.   Increase in Amoco Interest ..................................................11
         3.7.   Withdrawal of Capital .......................................................12
         3.8.   Interest on Capital .........................................................12
         3.9.   Construction Costs ..........................................................12
         3.10.  Capital Accounts ............................................................13
  4.     REPRESENTATION AND WARRANTIES ......................................................14
         4.1.   All Partners ................................................................14
         4.2.   Representations of DEVCO and Warren Regarding the Fractionation Facilities...15
         4.3.   Inspection and Condition of Fractionator Facility ...........................16
         4.4.   Partners' Knowledge and Expertise ...........................................16
         4.5.   Environmental Laws ..........................................................17
         4.6.   Disclaimer of Representations and Warranties ................................17
         4.7.   Partnership's Assumption of Obligations .....................................17
         4.8.   Cross Indemnifications and Defense Costs ....................................17
         4.9.   Exclusive Remedy ............................................................20
         4.10.  Survival of and Scope of Indemnities ........................................20
  5.     OTHER AGREEMENTS ...................................................................20
         5.1.   Partner Fractionation Agreements ............................................20
         5.2.   Conveyancing Documents ......................................................20
         5.2.   Amoco Parent Guaranty .......................................................21

                                       i
<Page>

         5.3. Assignment of Other Agreements ................................................21
         5.4. Operating Agreement ...........................................................21
  6.     DISTRIBUTIONS ......................................................................21
         6.1. Monthly Distributions .........................................................21
         6.2. Distributions on Termination ..................................................21
  7.     ALLOCATIONS TO PARTNERS ............................................................22
         7.1. In General ....................................................................22
         7.2. Other Tax Allocations .........................................................22
         7.3. Special Allocations ...........................................................22
         7.4. Curative Allocations ..........................................................23
  8.     MANAGEMENT OF THE PARTNERSHIP ......................................................24
         8.1.  Management Committee .........................................................24
         8.2.  Meeting Notice ...............................................................24
         8.3.  Voting Procedures ............................................................24
         8.4.  Vote Required ................................................................24
         8.5.  Minutes ......................................................................24
         8.6.  Matters Requiring Unanimous Approval .........................................25
         8.7.  Authority to Bind the Partnership ............................................27
         8.8.  Duties of Managing General Partner ...........................................27
         8.9.  Change of Managing General Partner ...........................................27
         8.10. Duties of General Partners and Others Controlling General Partners ...........28
  9.     OPERATION OF THE FACILITY ..........................................................28
         10.10. Change of Operator ..........................................................29
         10.11. Resignation of Operator .....................................................29
         10.12. Removal of Operator .........................................................29
         10.13. Successor Operator ..........................................................29
         10.14. Transactions With Affiliates ................................................30
  10.    INDEMNITIES AND INSURANCE ..........................................................30
         10.1. Definitions ..................................................................30
         10.2. Obligations of Partner .......................................................31
         10.3. Indemnity to Managing General Partner ........................................31
         10.4. Insurance ....................................................................32
         10.5. Policy Requirements ..........................................................32
         10.6. Third Parties ................................................................33
         10.7. Notice .......................................................................33
  11.    TRANSFERABILITY OF PERCENTAGE INTERESTS ............................................33
         11.1. Transfer to Affiliates .......................................................33
         11.2. Transfers to Parties Other Than Affiliates ...................................33
         11.3. Right of First Refusal .......................................................33
         11.4. Changes in Control ...........................................................34
         11.5. General Conditions of Transfers ..............................................34

                                       ii
<Page>

  12.    WINDING UP AND TERMINATION OF THE PARTNERSHIP ......................................35
         12.1.  Events Requiring Winding Up .................................................35
         12.2.  Partner's Purchase of Property ..............................................35
         12.3.  Time of Liquidation .........................................................35
         12.4.  No Liability for Return of Capital ..........................................35
         12.5.  Liquidation Procedure .......................................................36
         12.6   Negative Capital Account Balances ...........................................36
  13.    ALTERNATIVE DISPUTE RESOLUTION .....................................................36
  14.    GENERAL PROVISIONS .................................................................39
         14.1.  Notices .....................................................................39
         14.2.  Survival of Rights ..........................................................41
         14.3.  Amendment and Waiver ........................................................41
         14.4.  Agreement in Counterparts ...................................................41
         14.5.  Governing Law ...............................................................41
         14.6.  Additional Documents ........................................................41
         14.7.  Severability ................................................................41
         14.8.  Sections, Exhibits and Schedules ............................................42
         14.9.  Attorneys' Fees .............................................................42
         14.10. Power of Attorney ...........................................................42
         14.11. Principles of Construction and Interpretation ...............................43
         14.12. Setoffs and Counterclaim ....................................................43
</Table>

                                      iii
<Page>

EXHIBITS

A.    Accounting Procedures

B.    Income Tax Matters

C.    Warren/DEVCO Contributed Assets

      Part I         -      Surface Lease Area
      Part II        -      Fractionator
      Part III       -      Related Facilities
      Part IV        -      Permits
      Part V         -      Contracts
      Part VI        -      Surface Lease Area Excluded Assets

D.    Lease Agreement (Surface Lease Area and Water Rights Areas)

E.    Partner Fractionation Agreements

F.    Form of Assignment and Bill of Sale

G.    Disclosure Schedule

H.    Amoco Oil Company Guaranty

                                      iv
<Page>

                          LIMITED PARTNERSHIP AGREEMENT
                                       OF
                         CEDAR BAYOU FRACTIONATORS, L.P.

      THIS LIMITED PARTNERSHIP AGREEMENT ("Agreement") is entered into this 1st
day of January, 1998, to be effective that same date, by and between Downstream
Energy Ventures Co., L.L.C., a Delaware limited liability company, as a General
Partner ("DEVCO"), Warren Petroleum Company, Limited Partnership, a Delaware
limited partnership, as a Limited Partner ("Warren") and Amoco MB Fractionation
Company, a Delaware corporation, as a Limited Partner ("Amoco"), sometimes
referred to individually as "Party" and collectively as "Parties".

                                    PREMISES

      A. Warren currently owns and operates the Fractionation Facility for the
purpose of fractionation of natural gas liquids delivered by various third
parties to the Mont Belvieu, Texas, area;

      B. On the Effective Date of this Agreement, DEVCO has acquired an
undivided two percent (2%) ownership interest in and to the Fractionation
Facility; and

      C. DEVCO, Warren and Amoco wish to form a business combination for the
purpose and of jointly owning and operating the Fractionation Facility; and

      In consideration of the foregoing premises and the mutual covenants and
agreements contained in this Agreement, the Parties agree as follows:

1.    PARTNERSHIP FORMATION.

      1.1. FORMATION. Subject to the provisions of this Agreement, the Parties
do hereby form a limited partnership (the "Partnership") pursuant to the
provisions of the Delaware Revised Uniform Limited Partnership Act, Sections
1701 et seq. of Title Six of the Delaware Code (such Act, as amended from time
to time, or any successor statute or statutes thereto, being called the "Act").

      1.2. FILINGS AND FURTHER ACTION. Upon the request of the Managing General
Partner, the other General Partners and the Limited Partners shall promptly
execute and deliver all such certificates and other instruments conforming
hereto as shall be necessary for the Managing General Partner to accomplish all
filing, recording, publishing and other acts appropriate to comply with all
requirements for the formation and operation of limited partnership under the
laws of the State of Delaware and for the qualification and operation of a
limited partnership in all other jurisdictions where the Partnership shall
propose to conduct business. This Agreement shall constitute the Agreement of
Partnership. The Partners also agree to make all necessary filings in the State
of Texas and execute all other documents necessary to comply with the laws of
the State of Texas regarding

                                       1
<Page>

the qualification of the Partnership to engage in business therein. In
addition, to the extent the Partners agree to engage in business in other
states, the Partners shall execute such further documents and take such
further actions as shall be appropriate to comply with the requirements of
the laws for the formation and operation of a partnership in each such state.

      1.3. NAME. The name of the Partnership is Cedar Bayou Fractionators, L.P.

      1.4. PLACE OF BUSINESS; REGISTERED AGENT.

            1.4.1. The principal place of business of the Partnership shall be
            1000 Louisiana, Suite 5800, Houston, Texas 77002. The Managing
            General Partner, at any time and from time to time, may change the
            location of the Partnership's principal office as the Managing
            General Partner shall determine to be necessary or desirable.

            1.4.2. The registered office of the Partnership in the State of
            Delaware shall be 1209 Orange Street, Wilmington, New Castle County,
            Delaware 19801, and the registered agent for service of process on
            the Partnership at such registered office shall be The Corporation
            Trust Company. The registered office of the Partnership in the State
            of Texas shall be 811 Dallas Avenue, Houston, Texas 77002 and the
            registered agent for service of process on the Partnership at such
            registered office shall be CT Corporation System. The Management
            Committee, at any time and from time to time, may direct the
            Managing General Partner to change the Partnership's registered
            offices or registered agents or both by complying with the
            applicable provisions of the Act, and may establish, appoint and
            change additional registered offices and registered agents of the
            Partnership in such other states as the Management Committee shall
            determine to be necessary or advisable.

      1.5. PURPOSE. The purposes of the Partnership and the business to be
carried on by it, subject to the limitations contained elsewhere in this
Agreement, are to engage in the business of providing natural gas liquids
fractionation services for natural gas liquids being delivered by third
parties into the Mont Belvieu Area as same is defined below. The Partnership
will accomplish these purposes through the ownership and operation of the
Fractionation Facility and entering into agreements with the Partners, their
affiliates, and third parties for the fractionation of their owned and
controlled natural gas liquids delivered to Fractionation Facility.
Additionally, the Partnership may carry on any other activities necessary to,
in connection with, or incidental to the accomplishment of the foregoing
purposes. The Partners acknowledge that an Affiliate of Warren, Warren NGL,
Inc. ("Warren NGL") has a prior existing commitment pursuant to a
partnership agreement governing Gulf Coast Fractionators, a Texas general
partnership, ("GCF") as a general partner therein, to advise GCF of
fractionation opportunities in the Mont Belvieu Area regarding fractionation
of natural gas liquids for third parties and the Partners hereto agree that
actions taken by Warren NGL or by Warren in assisting Warren NGL pursuant to
its obligations to GCF shall not be in violation of any duties of

                                       2
<Page>

Warren hereunder.

      1.6. TERM. The Partnership commenced, on December 4, 1997 but as among the
Partners will be treated as formed, on the Effective Date and shall continue
until December 31, 2022, (the "Primary Term") and year to year thereafter (each
said year being and "Extended Term") unless and until any Partner or a group of
Partners holding collectively more than eighty-eight percent (88%) of the
Percentage Interests terminates this Agreement as of the end of either the
Primary Term or any successive Extended Term by giving written notice to all of
the other Partners at least nine (9) months prior to such termination date; and
the Partnership shall terminate as of the date of any such a termination of this
Agreement unless terminated or dissolved earlier in accordance with this
Agreement, or by law. The Primary Term and the Extended Terms, if any, will be
collectively referred to as the "Term" of this Agreement.

      1.7. WAIVER OF RIGHT OF PARTITION. All Property shall be owned by the
Partnership and no Partner shall have an ownership in the Property or any
portion thereof. Each Partner, to the extent permitted by applicable law, hereby
waives its right to partition of the Property and, to that end, agrees that it
will not seek or be entitled to partition of any Property, whether by physical
partition, judicial sale or otherwise, until the termination of this Agreement.

2.    DEFINED TERMS.

As used in this Agreement, the following terms have the meanings set forth
below, unless the context requires otherwise.

      "ACT" has the meaning set forth in Section 1.1.

      "ACCOUNTING PROCEDURES" shall mean the Accounting Procedures for the
      Partnership set forth in Exhibit A and incorporated herein by reference.

      "ADJUSTED CAPITAL ACCOUNT DEFICIT" means, with respect to any Partner, the
      deficit balance, if any, in such Partner's Capital Account as of the end
      of the relevant calendar year, after giving effect to the following
      adjustments: (i) credit to such Capital Account any amounts which such
      Partner is obligated to restore pursuant to any provision of this
      Agreement or is deemed to be obligated to restore pursuant to the
      penultimate sentences of Treasury Regulations Section 1.704-2(g)(1) and
      1.704-2(i)(5); and (ii) debit to such Capital Account the items described
      in Treasury Regulations Section 1.704-1(b)(2)(ii)(d)(4),
      1-704-1(b)(2)(ii)(d)(5), and 1.704-1(b)(2)(ii)(d)(6). This definition is
      intended to comply with the provisions of Treasury Regulations Section
      1.704-1(b)(2)(ii)(d) and shall be interpreted consistently therewith.

      "AFFILIATE" means, when used with respect to a specified Partner, any
      Person that directly,

                                       3
<Page>

      or indirectly through one or more intermediaries, controls or is
      controlled by or is under common control with the specified Partner. For
      purposes of this definition: "CONTROL" shall mean ownership of fifty
      percent (50%) or more of either the outstanding voting stock of the
      controlled Person, as to corporations, or other ownership interests which
      carry with them the right to direct the policies and management of the
      subject entity, as to non-corporate entities.

      "AGREEMENT" means this Limited Partnership Agreement.

      "CAPITAL CONTRIBUTION" means any amounts of cash or fair market value of
      property committed to the Partnership by a Partner pursuant to any
      portions of Section 3 hereof.

      "CAPITAL ACCOUNT" means the account to be maintained by the Partnership
      for each Partner in accordance with Section 3.10

      "CODE" shall mean the Internal Revenue Code of 1986, as amended from time
      to time.

      "CONSTRUCTION COST" means the cost of constructing any facility or
      equipment used or useful in the Partnership's' operations, or any
      expansion thereof; including, without limitation, materials, labor,
      equipment, permits, consulting fees, accounting and legal fees, insurance
      costs, contractors' fees, land and easement costs, administrative overhead
      charges allowed pursuant to Section 3.10(a) of the Accounting Procedures,
      and all other costs necessary or incidental thereto, excluding only any
      costs incurred by the Partners which comprise any portion of their Initial
      Investment and any interest, amortization or overhead costs incurred by a
      Partner.

      "CONVEYANCING DOCUMENTS" means those documents described in Section 5.2.

      "DAY" or "DAILY" shall mean a twenty-four (24) hour period commencing 7:00
      a.m. Central Standard or Daylight Savings time, as applicable, and
      extending until 7:00 a.m. Central Standard or Daylight Savings time, as
      applicable, on the following Day.

      "DISCLOSURE SCHEDULE" means Exhibit G to this Agreement.

      "DISTRIBUTABLE CASH" shall mean with respect to any period all cash
      revenues of the Partnership including, without limitation, those amounts
      received from the Operator pursuant to the Operating Agreement (not
      including (i) Capital Contributions, (ii) funds received by the
      Partnership in respect of indebtedness incurred by the Partnership, (iii)
      interest or other income earned on temporary investment of Partnership
      funds pending utilization, and (iv) proceeds from the sale of assets in
      partial or complete liquidation of the Partnership) less the sum of the
      following: (x) all amounts expended by the Partnership pursuant to this
      Agreement in such period; and (y) such working capital or reserves or
      other amounts as the

                                      4
<Page>

      Managing General Partner reasonably determines to be necessary or
      appropriate for the proper operation of the Partnership business and/or
      its winding up and liquidation.

      "DISTRIBUTION" means a distribution of cash or property made by the
      Partnership to a Partner under the terms of this Agreement.

      "EFFECTIVE DATE" means the date designated as such in the first Section of
      this Agreement. As among the Partners, the Partnership will be treated as
      formed on the Effective Date.

      "ENVIRONMENTAL CONDITION" as used herein means any condition which exists
      that affects the quality of the air, water, surface or subsurface of the
      ground in such a manner that the existence of such condition is unlawful
      under any Environmental Law, including Warren's failure to acquire or
      maintain any necessary air or water permits.

      "ENVIRONMENTAL CONTAMINANT" shall mean Hazardous Substances, Hazardous
      Waste or Hazardous Materials.

      "ENVIRONMENTAL LAWS" shall mean any and all laws, regulations, rules,
      orders, ordinances, requirements or determinations of any governmental
      authority, with jurisdiction, (including court rulings establishing common
      law liability) pertaining to the Release of Environmental Contaminants,
      and any other applicable regulations, rules, ordinances, codes, licenses,
      or orders by any governmental agencies in effect which govern the quality
      of the air, water, surface or subsurface of the ground, including, without
      limitation, the presence of any underground storage tanks or drums; and
      including, without limitation, the Comprehensive Environmental Response,
      Compensation and Liability Act (CERCLA), as amended by Superfund
      Amendments and Reauthorization Act (SARA), 42 U.S.C. 9 Sections 6901 et
      seq.; Resource Conservation and Recovery Act (RCRA), as amended by the
      Solid Waste Disposal Act (SWDA), 42 U.S.C. Sections 6901 et seq.; Federal
      Water Pollution Control Act (FWPCA), as amended by the Clean Water Act
      (CWA), 33 U.S.C. Sections 1251 et seq.; Clean Air Act (CAA), 42 U.S.C.,
      Sections 7401 et seq.; Toxic Substances Control Act (TOSCA), 15 U.S.C.
      Sections 2601 et seq, and any similar state enactments.

      "FRACTIONATION FACILITY" or "FACILITY" shall mean the following property,
      facilities and related assets which are to be contributed by DEVCO and
      Warren to the Partnership pursuant to the terms hereof:

      (1)   SURFACE LEASE AREA, WATER RIGHTS AND EASEMENT. A real property
            surface lease (the "LEASE AGREEMENT") in the form attached hereto as
            Exhibit D for a term coterminous with this Agreement granting the
            Partnership use of the surface property described in Part I of
            Exhibit C (the "SURFACE LEASE AREA"), which comprises the areas on
            which the Fractionator (as defined immediately below) is situated
            and the use

                                       5
<Page>

            of certain water wells located on the "WATER RIGHTS AREAS"
            described on Exhibit A to the Lease Agreement, and the right to
            extract water therefrom; and an easement for the term hereof to
            allow the continued presence of, and Partnership access to, all
            Related Facilities, as defined below.

      (2)   FRACTIONATION FACILITY. All of Warren's and DEVCO's right, title and
            interest in and to all the equipment, personal property and
            facilities comprising that certain natural gas liquids fractionation
            facility, and other facilities appurtenant thereto and necessary for
            the operation of said fractionation facility, all as same are
            located in the Surface Lease Area (as defined immediately above), as
            such fractionator facility is generally described in Part II of
            Exhibit C (THE "FRACTIONATOR"), less and except those assets
            described as "Excluded Assets" in Part IV of Exhibit C.

      (3)   RELATED FACILITIES. All of Warren's and DEVCO's right, title and
            interest in and to those facilities and equipment outside of the
            Surface Lease Area related to the Fractionator and which are
            described in Part III of Exhibit C, and excluding any items not
            expressly described therein (the "RELATED FACILITIES").

      (4)   PERMITS. All of Warren's right, title and interest in and to all of
            the environmental and other governmental permits, licenses, orders,
            franchises and related instruments or rights necessary to the
            ownership or operation of any portions of the Fractionator as
            described in Exhibit C, and which in accordance with the applicable
            law or the terms of such instruments are not to be maintained in the
            name of the Operator of the Fractionator and that, by their terms,
            may be assigned ("PERMITS"), as described in Part IV of said
            Exhibit C.

      (5)   CONTRACTS. All of Warren's and DEVCO's right, title and interest in
            and to those certain contracts and agreements relating solely to the
            Fractionator that, by their terms, may be assigned including but not
            limited to fractionation services agreements, gas supply, electrical
            and other utilities purchase agreements, maintenance and services
            agreements and intellectual property licensing and confidentiality
            agreements, as same are listed in Part V of Exhibit C ("CONTRACTS").

      (6)   RECORDS. All of Warren's and DEVCO's right, title and interest in
            and to all files, records and other data in the actual possession of
            Warren or DEVCO, necessary for the Partnership's operation of the
            Fractionator (except to the extent same relate to any retained
            properties still owned by Warren and DEVCO); including, but not
            limited to, all operational records, technical records, processing
            records, measurement, pipeline balancing and connection agreements,
            United States Department of Transportation and other governmental
            agency-required files, contract files, copies of accounting files,
            and copies of computer spreadsheets used for accounting and
            allocations, but

                                       6
<Page>

            excluding tax records and accounting records which relate
            exclusively to accounting periods prior to the date of contribution
            of the Fractionator to the Partnership. ("RECORDS").

      (7)   EXCLUDED ASSETS. "FRACTIONATOR FACILITY" is understood to expressly
            exclude: (i) any of the equipment, facilities, or assets located
            within the Surface Lease Area and which are described in Part VI of
            Exhibit C ("SURFACE LEASE AREA EXCLUDED ASSETS"); and (ii) any and
            all assets, facilities or properties outside of the Surface Lease
            Area which are not expressly defined above as being Related
            Facilities; (all of same being collectively referred to herein as
            the "EXCLUDED ASSETS").

      "GENERAL PARTNER" means DEVCO and any other Person who becomes an
      additional or successor general partner of the Partnership pursuant to the
      provisions of this Agreement.

      "HAZARDOUS MATERIAL" shall mean any substance that is defined or listed as
      a hazardous or toxic substance under any Environmental Laws (as same are
      in effect as of the Effective Date) or that is otherwise regulated or
      prohibited or subject to investigation or remediation under any
      Environmental Laws.

      "HAZARDOUS SUBSTANCE" and "RELEASE" shall have the meaning specified in
      CERCLA, or any successor statute, unless such terms have been given
      broader meaning by laws, regulations, rules, orders, ordinances,
      requirements or determinations of any governmental authority of the State
      of Texas having jurisdiction (including courts establishing common law
      liability), in which case such broader meaning shall apply.

      "HAZARDOUS WASTE" and "DISPOSE" shall have the meanings specified in RCRA,
      or any successor statute, unless such terms have been given broader
      meaning by laws, regulations, rules, orders, ordinances, requirements or
      determinations of any governmental authority of the State of Texas having
      jurisdiction (including courts establishing common law liability), in
      which case such broader meaning shall apply.

      "INITIAL INVESTMENT" means, the fair market value agreed and stipulated to
      by the Partners of the property and other initial Capital Contributions
      which each Partner is obligated to contribute to the Partnership pursuant
      to Sections 3.1, 3.2 and 3.3 of this Agreement; but excluding any
      amortization, interest or depreciation costs incurred by or on behalf of
      either Partner.

      "KNOWLEDGE" means, with respect to a Party to this Agreement, the actual
      knowledge of any officer or manager directly reporting to an officer of
      such Party in charge of a discrete business area or a subsidiary having
      responsibility for the matter in question and does not include such
      knowledge as could have been obtained by such Persons from employees or

                                       7
<Page>

      records of that Party after doing an investigation into the subject matter
      in question.

      "LIMITED PARTNER" shall mean any Person executing this Agreement below in
      the capacity of a limited partner of the Partnership and includes any
      Person admitted as an additional limited partner or the Partnership
      pursuant to the provisions of this Agreement, or who receives an
      assignment, made in compliance with the transfer restrictions in this
      Agreement, of any limited partnership interest in the Partnership unless
      such assignee elects to convert same to a general partnership interest.
      "Limited Partners" means two or more Persons holding limited partnership
      interests in the Partnership when acting in such capacity.

      "MANAGEMENT COMMITTEE" has the meaning set out in Section 8.1.

      "MANAGING GENERAL PARTNER" shall mean DEVCO or such other General Partner
      as is named to be the Managing General Partner pursuant to the provisions
      of Section 9.10 of this Agreement.

      "MONT BELVIEU AREA" shall mean the geographical area surrounding the Mont
      Belvieu area, including the following counties: Brazoria, Chambers, Fort
      Bend, Galveston, Harris, Jefferson, Liberty and Montgomery.

      "MONTH" or "MONTHLY" shall mean a period commencing at 7:00 a.m. Central
      time on the first Day of a calendar month and ending at 7:00 a.m. Central
      time on the first Day of the next succeeding calendar month.

      "NET OPERATING REVENUE OR LOSSES" means Operating Revenues less Operating
      and Maintenance Expenses or Reduced Operating Expenses whichever is
      applicable.

      "OPERATING AGREEMENT" means the Operating Agreement dated as of the
      Effective Date between the Managing General Partner on behalf of the
      Partnership and the Operator of the Facilities, as the same may be
      amended, modified or supplemented from time to time in accordance with the
      terms thereof and hereof.

      "OPERATING AND MAINTENANCE EXPENSES" means expenditures made and costs
      incurred by the Operator in connection with the operation of the
      Fractionator and as more fully defined and set forth in this Agreement

      "OPERATING REVENUES" means revenues of the Partnership in respect of its
      business.

      "OPERATOR" shall mean the party with whom the Partnership contracts to
      serve as operator of the Facility and the day to day business affairs of
      the Partnership. The Operator shall be supervised by the Managing General
      Partner but is not required to be a Partner. A Limited

                                       8
<Page>

      Partner may serve as Operator only pursuant to a written operating
      agreement and in such case is understood to be acting solely in its
      capacity as an independent contractor and not in its capacity as a
      Partner.

      "PARTNERS" means all of the General Partners and Limited Partners under
      the terms of this Agreement.

      "PARTNERS FRACTIONATION AGREEMENTS" shall mean those agreements shown in
      Exhibit E to be executed by Warren and Amoco, or their designated
      Affiliates.

      "PARTNERSHIP" has the meaning set forth in Section 1.1.

      "PERCENTAGE INTERESTS" shall mean the Partner's respective percentage of
      ownership in the Partnership, subject to changes pursuant to Section 3.6
      and Article 11, it being hereby specified that the Partners' initial
      Percentage Interest shall be as follows:

                          GENERAL PARTNERSHIP INTERESTS
         GENERAL PARTNER                                   PERCENTAGE INTEREST

         DEVCO                                                     2%

                          LIMITED PARTNERSHIP INTERESTS

         LIMITED PARTNER                                   PERCENTAGE INTEREST
         Warren                                                  86.24%
         Amoco                                                   11.76%

                        Total Percentage Interests                100%

      Any subsequent parties who become Partners hereunder in compliance with
      the provisions of this Agreement governing transfers of Partnership
      interests shall hold such Percentage Interests as are designated in the
      transfers to them.

      "PERSON" shall mean any individual, corporation, association, partnership
      (general or limited), joint venture, trust, estate, limited liability
      company, limited liability partnership, or other legal entity or
      organization.

      "PROPERTY" means all assets owned by the Partnership or any single asset
      owned by the

                                       9
<Page>

                    'Confidential Treatment Requested'

      Partnership.

      "RAW PRODUCT" means the mixed stream of demethanized natural gas liquids
      produced by natural gas processing plants prior to such liquids being
      fractionated into final, Specification Products.

      "REDUCED OPERATING EXPENSES" means the net reduction in Operating and
      Maintenance Expenses due to any Construction Costs.

      "SPECIFICATION PRODUCTS" means all the final product produced at the
      Fractionator by fractionation of natural gas liquids received at the
      Fractionator including, but not limited to, ethane, propane, isobutane,
      normal butane and natural gasoline.

      "TERM" has the meaning set out in Section 1.6.

      "THIRD PARTY FRACTIONATION AGREEMENTS" means any agreement to provide
      fractionation and processing services to a third party entered into by the
      Partnership on or after the Effective Date.

      "TRANSFERRING PARTNER" is defined in Section 11.3.

      "TREASURY REGULATION" means the regulations (including temporary
      regulations) promulgated by the United States Department of the Treasury
      pursuant to and in respect of provisions of the Code. All references to
      sections of the Treasury Regulations shall include any corresponding
      provision or provisions of succeeding, similar or substitute, temporary or
      final Treasury Regulations.

3. INITIAL CAPITAL CONTRIBUTIONS. The initial Capital Contributions of the
Partners shall be as follows and shall be made by each of them on or before
December 31, 1997:

         3.1. WARREN. Warren shall convey, as of the Effective Date of this
   Agreement, a ninety eight percent (98%) undivided ownership interest in and
   to the Fractionation Facility to the Partnership, as its Initial Investment,
   by execution and delivery of an Assignment and Bill of Sale substantially in
   the form attached to hereto as Exhibit F.

      3.2. DEVCO. DEVCO shall, as of the Effective Date of this Agreement, a two
   percent (2%) undivided ownership interest in and to the Fractionation
   Facility by execution and delivery of Assignment and Bill of Sale
   substantially in the form of Exhibit F, and pay a cash Capital Contribution
*  in the amount of [REDACTED] to the Partnership, as its Initial Investment.

      3.3. AMOCO. Amoco shall contribute to the Partnership, as of the
   Effective Date of this

                                       10
<Page>

                     'Confidential Treatment Requested'

* Agreement, a cash Capital Contribution in the amount of [REDACTED] as its
  Initial Investment.

      3.4. DEFAULT IN MAKING OF CAPITAL CONTRIBUTIONS. In the event any Partner
  shall fail to pay or deliver when due its Initial Investment or any other
  Capital Contribution and/or fail to honor any other obligation as required
  by this Agreement, and shall fail to cure such default within fifteen (15)
  Days after notice thereof is given to such Partner, then, unless cure is
  prevented by an event of force majeure:

            3.4.1. Any Distribution otherwise payable pursuant to Section 6
            hereof in respect of the defaulting Partner's Percentage Interest
            shall be paid instead, ratably, to the other Partners but only until
            the aggregate amount of Distributions thus reallocated equals two
            times the amount or market value of the default;

            3.4.2. To the extent that the non-defaulting Partners or the
            Partnership suffer any loss or damage as a result of such default
            and any resulting dissolution or termination of this Agreement,
            including, without limitation, lost revenues or adverse tax
            consequences, the defaulting Partner shall be fully and solely
            liable therefor, and

            3.4.3. To the extent the defaulting Partner has been assigned
            specific duties or authority under Section 9 hereof as Operator, the
            non-defaulting Partners may designate another Partner or contract
            with a non-Partner to perform such duties or assume such authority
            without the consent or agreement of the defaulting Partner.

      3.5. OTHER REMEDIES. The above Section 3.4 shall be in addition to, and
  not in lieu of, any other rights and remedies as may be available to the
  non-defaulting Partner(s), all of which shall remain available.

      3.6. INCREASE IN AMOCO INTEREST. Between July 1, 1998, and December 31,
  2002, Amoco shall have the right to increase its Limited Partnership
  Percentage Interest in the Partnership up to a total of 24.5% through one of
  the following methods:

            3.6.1. If agreed to by Warren, a purchase of a portion of Warren's
            Percentage Interest in the Partnership in exchange for cash or
            assets acceptable to Warren, in which case the amount of increase in
*           Amoco's Partnership Interest would be equal to the [REDACTED]
*           divided by the sum of: 1) [REDACTED] and 2) [REDACTED]

            3.6.2. At Amoco's sole election and option, by making additional
            cash Capital Contributions to the Partnership; in which case Amoco's
            total resulting Percentage

                                       11
<Page>

                     'Confidential Treatment Requested'

*           Interest would be equal to the sum of (a) [REDACTED] and (b)
*           [REDACTED], divided by the sum of the three following amounts: 1)
*           [REDACTED], 2) [REDACTED], and 3) [REDACTED]

      3.7. WITHDRAWAL OF CAPITAL. No Partner shall have any right to withdraw or
make a demand for withdrawal or return of any of its Capital Contributions
capital without the consent of all Partners or as provided for in this
Agreement. An unrepaid Capital Contribution is not a liability of the
Partnership or of any Partner. A Partner is not required to contribute or to
lend cash or property to the Partnership to enable the Partnership to return any
Partner's Capital Contribution.

      3.8. INTEREST ON CAPITAL. Except to the extent that interest income to the
Partnership is allocated to them, no interest shall be paid to Partners by the
Partnership on any Capital Contribution.

      3.9. CONSTRUCTION COSTS.

            3.9.1. Any Construction Costs incurred by the Partnership in a
            manner authorized hereunder shall be allocated under this Agreement
            to the Partners herein according to their respective Percentage
            Interests. Any net revenue attributable to additional facilities or
            modifications to existing facilities for which the Construction
            Costs were shared by the Partners in amounts proportionate to their
            Percentage Interests under this Section shall be allocated among
            them in that same proportion.

            3.9.2. In the event a Partner does not desire to contribute its
            proportionate share of any additional Construction Costs after
            receipt of all material information in the possession of or
            available to the other Partners (a "Non-Participating Partner"),
            including without limitation, opportunities or commitments to use
            or otherwise exploit the additional facilities, revenue projections
            attributable to the additional facilities and any other material
            information, then the other Partners who do wish to participate
            (the "Participating Partners") shall have the right to direct the
            Operator to complete such a project and contribute amounts equal
            to the costs for the construction of the additional facilities. In
            such an instance, the Participating Partners shall be fully
            responsible for contributing to the Partnership additional capital
            equal to such costs. The net revenue attributable to any
            additional facilities shall be determined by agreement of the
            Partners and should they fail to agree to same, such allocation
            shall be resolved through the dispute resolution procedures set
            forth in Article 13 below. Additionally, the Participating Partners
            shall receive, as a

                                       12
<Page>

            Distribution from the Partnership, in compensation for their costs
            and risks one hundred percent (100%) of the Partnership's
            incremental Net Operating Revenue attributable to the new
            facilities, which shall be distributed to the Participating Partners
            on a Monthly basis, until the Participating Partner has received an
            amount equal to 200% of that Participating Partner's investment in
            the Construction Costs associated with the new facilities. If said
            200% is not received within five (5) years following commencement of
            operations of the new facilities then, commencing in the sixth year
            following such commencement of operations and for each year
            thereafter continuing through the fifteenth year following same,
            that percentage shall be increased by ten percent (10%) each year,
            but never to exceed, however, 300%. After the Participating Partners
            have received such Distributions of the Net Operating Revenue
            attributable to the new facilities equal to the stated percentage of
            each of the Partners' shares of the Construction Costs, then all
            future Distributions attributable to the new facilities shall be
            made to each Partner according to its Percentage Interest in the
            Partnership.

            3.9.3. Section 3.9.2 notwithstanding, no Partner may decline or
            refuse to contribute any cash Capital Contribution of which the
            Managing General/Partner gives notice when same is required to
            complete any work necessary to comply with any laws or regulations
            applicable to the Facility and its continued operation. Provided,
            however, the Management Committee may direct the Managing General
            Partner to cancel any such a cash Capital Contribution notice, if
            it determines that it is in the best interest of the Partnership to
            either cease the operations which give rise to the applicable legal
            requirements in question on the modify operations in such a manner
            that compliance with such laws and regulations can be achieved with
            cash then available in the Partnership's bank accounts in excess of
            the "Required Working Capital" (as defined in the Operating
            Agreement) which Operator is entitled to retain pursuant to the
            Operating Agreement.

      3.10. CAPITAL ACCOUNTS. A Capital Account shall be established and
maintained for each Partner. Each Partner's Capital Account shall be increased
by (a) the amount of money contributed by that Partner to the Partnership, (b)
the fair market value of property contributed by that Partner to the Partnership
(net of liabilities secured by such contributed property that the Partnership is
considered to assume or take subject to under Section 752 of the Code), and (c)
allocations to that Partner of Partnership income and gain (or items thereof),
including income and gain exempt from tax and income and gain described in
Treasury Regulation Section 1.704-1(b)(2)(iv)(g), but excluding income and
gain described in Treasury Regulations Section 1.704-1(b)(4)(i), and shall be
decreased by (d) the amount of money distributed to that Partner by the
Partnership, (e) the fair market value of property distributed to that Partner
by the Partnership (net of liabilities secured by such distributed property that
such Partner is considered to assume or take subject to under Section 752 of the
Code), (f) allocations to that Partner of expenditures of the Partnership
described (or treated as described)

                                       13
<Page>

in Section 705(a)(2)(B) of the Code, and (g) allocations of Partnership loss and
deduction (or items thereof), including loss and deduction described in Treasury
Regulation Section 1.704-1(b)(2)(iv)(g), but excluding items described in (f)
above and loss or deduction described in Treasury Regulation Sections
1.704-1(b)(4)(i) or 1.704-1(b)(4)(iii). The Partners' Capital Accounts shall
also be maintained and adjusted as permitted by the provisions of Treasury
Regulation Section 1.704-1(b)(2)(iv)(f) and as required by the other provisions
of Treasury Regulation Sections 1.704-1(b)(2)(iv) and 1.704-1(b)(4), including
adjustments to reflect the allocations to the Partners of depreciation,
depletion, amortization, and gain or loss as computed for book purposes rather
than the allocation of the corresponding items as computed for tax purposes, as
required by Treasury Regulation Section 1.704-1(b)(2)(iv)(g). Thus, the
Partners' Capital Accounts shall be increased or decreased to reflect a
revaluation of the Partnership's property on its books based on the fair market
value of the Partnership's property on the date of adjustment immediately prior
to (A) the contribution of money or other property to the Partnership by a new
or existing Partner as consideration for a Percentage Interest or an increased
Percentage Interest (B) the distribution of money or other property by the
Partnership to a Partner as consideration for a Percentage Interest, or (C) the
liquidation of the Partnership. Upon the Disposition of all or a portion of a
Percentage Interest, the Capital Account of the Transferring Partner that is
attributable to such Percentage Interest shall carry over to the transferee in
accordance with the provisions of Treasury Regulation Section
1.704-1(b)(2)(iv)(l).

4. REPRESENTATIONS AND WARRANTIES.

      4.1. ALL PARTNERS. Each Partner, upon becoming a Party to this Agreement,
represents, warrants and agrees that:

            4.1.1. It is either a corporation, limited liability company or
            limited partnership duly organized, validly existing and in good
            standing under the laws of the state where it was organized or
            incorporated, as the case may be, and has the power and authority to
            own (or lease) and use its properties and carry on its business as
            presently conducted;

            4.1.2. It has all requisite power and authority to execute, deliver
            and perform this Agreement and any other agreements required herein
            and to consummate the transactions contemplated by all the
            aforesaid;

            4.1.3. The execution, delivery and performance by it of this
            Agreement and any other agreements required herein and the
            consummation by it of the transactions contemplated by all of the
            aforesaid have been duly authorized by all necessary action on the
            part of such Partner;

            4.1.4. This Agreement and any other agreements required herein have
            been or will

                                       14
<Page>

            be duly and validly executed and delivered by it, and each such
            agreement constitutes the legal, valid and binding obligation of it
            enforceable in accordance with its terms, subject to bankruptcy,
            reorganization, insolvency, and similar laws of general application
            relating to or affecting the rights of creditors;

            4.1.5. The execution, delivery and performance of this Agreement
            and any other agreements required herein and the consummation by it
            of the transactions contemplated by all the aforesaid will not, (i)
            violate any applicable law, (ii) violate any order applicable to it
            or the assets contributed to the Partnership by it, or (iii)
            conflict with, or result in any material breach or default under its
            organization documents, or (iv) conflict with, or result in any
            material breach or default under any legally binding commitment,
            restriction or obligation to which it is bound or subject to, or
            result in the creation of any lien on the property of the
            Partnership or otherwise adversely affect the property of the
            Partnership or the Partnership; and

            4.1.6. It will not voluntarily cause a dissolution or termination of
            the Partnership, technical or otherwise, by failure to maintain its
            corporate existence or by any other act or omission to act.

      4.2. REPRESENTATIONS OF DEVCO AND WARREN REGARDING THE FRACTIONATION
FACILITIES.

            4.2.1. TITLE. DEVCO and Warren have conveyed to the Partnership, as
            of the Effective Date, all of their right, title and interest in and
            to the Fractionation Facilities to the Partnership but shall not,
            and do not hereby, warrant title in any manner other than as
            follows: DEVCO and Warren do warrant and agree to defend any claims
            by third parties claiming title or ownership by, through or under
            DEVCO or Warren, but not otherwise, with regard to the use of the
            Surface Lease Area, Water Rights Areas and the title to the
            Fractionator and the Related Facilities and DEVCO's and Warren's
            right to enter into the Lease Agreement or convey the Fractionator
            and the Related Facilities; and, additionally, that Warren has no
            Knowledge of any parties asserting any claims contrary to Warren's
            possession, use and title to the Fractionation Facility.

            4.2.2. COMPLIANCE WITH LAWS. Warren, to the best of its Knowledge
            and except as to any matters described in the Disclosure Schedule,
            is in compliance with all permits, contracts and agreements relating
            to the Fractionator Facility, and is in compliance with all laws,
            including Environmental Laws, rules and regulations of federal,
            state or local entities which have jurisdiction over Warren or the
            Fractionator Facility.

            4.2.3. LEGAL ACTIONS. Except as shown in the Disclosure Schedule,
            there are no lawsuits, orders, decrees, injunctions or
            administrative, arbitration or other

                                       15
<Page>

            proceedings, pending or, to the Knowledge of Warren, threatened
            against the Fractionator Facility or which could require a change in
            the manner of operations of the Fractionator or use of the
            Fractionator Facility.

            4.2.4. INTELLECTUAL PROPERTY

                  (1) ASSETS. To Warren's Knowledge, the Disclosure Schedule
            contains a true and complete list of all agreements and assets
            governing intellectual property assets which are reasonably
            necessary for lawful operation of the Fractionation Facility,
            including but not limited to license agreements, patents and
            technical information.

                  (2) LICENSE OBLIGATIONS. To Warren's Knowledge, all licenses
            agreements granting Warren the right to use and possession of the
            intellectual property assets listed in the Disclosure Schedule are
            in full force and effect, all fees and payments that are accrued
            under the terms of same have either been paid in full or are not yet
            due, and Warren has received no notice of default from the parties
            licensing same nor to Warren's Knowledge are there any material
            breaches or defaults.

                  (3) NON-INFRINGEMENT. Warren has no Knowledge of any unexpired
            U.S. patents, other than those subject to the agreements listed in
            the Disclosure Schedule or within the scope of a license agreement
            listed in the Disclosure Schedule, that are reasonably likely to be
            infringed by the manufacture or processing of any Raw Product or
            Specification Product which are manufactured or processed by the
            Partnership or are proposed to be manufactured or processed by the
            Partnership and Warren has received no summons, complaint or other
            information suggesting any possible infringement of any unexpired
            patents.

      4.3. INSPECTION AND CONDITION OF FRACTIONATOR FACILITY. Amoco acknowledges
that, prior to its execution of this Agreement, (i) it has been afforded access
to and the opportunity to inspect the Fractionator Facility, (ii) it has
inspected the Fractionator Facility to the extent it deems necessary or
advisable, and (iii) it is relying upon its own inspections and investigation in
order to satisfy itself as to the condition and suitability of the Fractionator
Facility. Therefore, the Partners agree that the Partnership is receiving and
accepting the conveyance of the Fractionator Facility, and the tangible assets
comprising same, on an "AS IS" and "WHERE IS" basis and agrees to assume all
risks with respect to the Fractionator Facility, whether or not revealed by any
of the Partners' investigation, as of the Effective Date.

      4.4. PARTNERS' KNOWLEDGE AND EXPERTISE. The Partners' are engaged in the
business of producing Raw Products and of transporting, fractionating and
selling Raw Products and Specifications Products and related oil and gas
businesses, and are familiar with all federal, state and

                                       16
<Page>

local statutes, laws, ordinances, rules and regulations applicable to the
Fractionator Facility and any associated business the Partnership intends to
conduct in connection with the Fractionator Facility after the execution hereof,
and has the expertise necessary to independently evaluate Warren's and DEVCO's
title to, and the condition, operation, suitability, performance and prospects
of, the Fractionator Facility.

      4.5. ENVIRONMENTAL LAWS. Amoco acknowledge that, prior to their execution
of this Agreement, they have independently conducted such environmental
inspections and investigations or obtained such environmental reports, audits,
studies, assessments and inspections as they deemed necessary or advisable and
that they are relying upon their own inspections and investigation in order to
satisfy themselves as to environmental matters pertaining to the Fractionator
Facility.

      4.6. DISCLAIMER OF REPRESENTATIONS AND WARRANTIES. EXCEPT AS TO MATTERS
EXPRESSLY INDEMNIFIED AGAINST IN THIS AGREEMENT, (A) PARTNERSHIP AND THE
PARTNERS ACCEPT THE ASSETS COMPRISING THE FRACTIONATOR FACILITY "AS IS" AND
"WHERE IS" AND WITH ALL FAULTS AND DEFECTS, WHETHER PATENT OR LATENT, (B)
NEITHER WARREN OR DEVCO MAKE ANY REPRESENTATION OR WARRANTIES OF ANY KIND,
WHETHER EXPRESS OR IMPLIED, WITH RESPECT TO ALL OR ANY OF SAID ASSETS,
INCLUDING, WITHOUT LIMITATION, ANY IMPLIED WARRANTIES OR MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE OR ANY REPRESENTATION WITH RESPECT TO THE
DESIGN, QUALITY, DURABILITY OR SUITABILITY OF THE FRACTIONATOR FACILITY, OR
ANY PORTIONS THEREOF, FOR A PARTICULAR PURPOSE, AND (C) NEITHER WARREN NOR
DEVCO MAKE ANY REPRESENTATIONS OR WARRANTIES OF ANY KIND, WHETHER EXPRESS OR
IMPLIED, IN CONNECTION WITH THE VALUE, CONDITION, FITNESS OR USE OF SAID
ASSETS OR THE PRESENCE, ABSENCE OR CONDITION OF ANY ENVIRONMENTAL CONTAMINANT
OR THE PRESENCE OR EXISTENCE OF ANY ENVIRONMENTAL CONDITION, EXCEPT FOR THOSE
ENVIRONMENTAL MATTERS DISCLOSED IN THE DISCLOSURE SCHEDULE.

      4.7. PARTNERSHIP'S ASSUMPTION OF OBLIGATIONS. From and after the Effective
Date the Partnership hereby assumes and shall be solely responsible for, and
shall perform and discharge all obligations, claims, liabilities, and taxes to
the extent same arise out of or relate to the ownership of the Fractionator
Facility or operation thereof from; including; without limitation, any
obligations under any Environmental Laws applicable from and after the Effective
Date to the extent same arise from or relate to conditions at or the operations
of the Fractionator Facility from and after the Effective Date, subject to the
Partnership's rights of indemnity under the express indemnities given in this
Agreement.

      4.8. CROSS INDEMNIFICATIONS AND DEFENSE COSTS. The following cross
indemnifications between the Partners and the Partnership with regard to the
Fractionator Facility shall be applicable to all claims, damages, costs,
demands, causes of action, fines, penalties, and losses (hereinafter referred to
as "Claims").

                                       17
<Page>

            4.8.1. Warren hereby agrees to indemnify, hold harmless and defend
            the Partnership and its individual Partners, their respective
            directors, officers, employees, partners, representatives,
            successors and assigns from and against all Claims (including
            reasonable attorney's fees), excluding Claims between the
            Partnership and its Affiliates regarding the Fractionator Facility,
            which are asserted at any time against the Partnership or any of the
            Partners, and which arise out of, and are directly related to, or
            are in any manner connected with Warren's operation of any portion
            of the Fractionator Facility or ownership of an interest in any
            portion of the Fractionator Facility, or any portion thereof, prior
            to the Effective Time, including, but not limited to, all Claims
            related to breaches or defaults of the Contracts, Claims for injury
            or death to persons, Claims for damage to property and Claim
            relating to violations of applicable laws, including Environmental
            Laws, rules, orders, regulations or codes. This indemnity in this
            Section includes indemnity against all Claims, costs of removal and
            disposal, and any liabilities arising from the presence at the
            facility, of certain volumes of naturally occurring radioactive
            material waste ("NORM") that results from the fractionation of Raw
            Product received at the Facility. Such NORM is predominantly Pb 210
            NORM waste and concentrates in particulate removed in the Facility's
            amine treating system filters and in sludge present in various
            vessels in the Facility, including sumps which capture water that is
            drained from various vessels. No disposal facility is currently
            available in the State of Texas for such NORM wastes and same will
            continue to be generated and stored at the Facility after the
            Effective Date until cost effective disposal services can be
            obtained by the Operator. The presence, and location, of such NORM
            wastes at the Facility is disclosed in the Disclosure Schedule and
            Warren agrees to clearly identify, mark and segregate NORM wastes
            generated prior to the Effective Date from those generated
            thereafter. PROVIDED, HOWEVER, THE INDEMNITY GIVEN BY WARREN IN THIS
            SECTION SHALL NOT EXTEND TO: (a) ANY CLAIMS WHICH ARE FOUNDED UPON
            ANY ALLEGED VIOLATION OF ENVIRONMENTAL LAWS TO THE EXTENT SAME ARE
            BASED ON LAWS OR REGULATIONS, OR AMENDMENTS THERETO, WHICH WERE NOT
            IN EFFECT ON THE EFFECTIVE DATE; OR (b) ANY CLAIMS WHICH ARE
            ASSERTED BY ANY THIRD PERSONS FROM AND AFTER THE EFFECTIVE DATE AND
            WHICH ARE FOUNDED UPON WARREN'S INTERPRETATION OR ADMINISTRATION OF
            ANY OF THE CONTRACTS PRIOR TO THE EFFECTIVE DATE TO THE EXTENT SUCH
            CLAIMS RELATE TO MONIES CLAIMED TO BE OWED, OR CONTRACTUAL DAMAGES
            ASSERTED, AND WHICH MONIES OR DAMAGES ARE ATTRIBUTABLE TO ANY
            ACCOUNTING PERIODS FROM AND AFTER THE EFFECTIVE DATE, AND THE
            PARTNERS EXPRESSLY ACKNOWLEDGES THAT THEY HAVE HAD AN ADEQUATE
            OPPORTUNITY TO REVIEW WARREN'S RECORDS REGARDING THE CONTRACTS AND
            WARREN'S ADMINISTRATION THEREOF AND THE PARTNERSHIP ASSUMES THE RISK
            OF ANY SUCH CONTRACTUAL CLAIMS AS TO CLAIMS FOR DAMAGES OR AMOUNTS
            OWED WHICH ARE ATTRIBUTABLE TO ACCOUNTING PERIODS FROM AND AFTER THE
            EFFECTIVE DATE.

                                       18
<Page>

            4.8.2. Warren and DEVCO also hereby agree to indemnify, hold
            harmless and defend the other Partners and the Partnership, their
            respective directors, officers, employees, partners,
            representatives, successors and assigns from and against all Claims
            (including reasonable attorney's fees) resulting from any inaccuracy
            in or breach of Warren's and DEVCO's representations and warranties
            under this Agreement.

            4.8.3. The Partners hereby agree that they and the Partnership shall
            indemnify, hold harmless and defend Warren and DEVCO, their
            respective directors, officers, employees, partners,
            representatives, successors and assigns from and against all Claim
            (including reasonable attorney's fees), which are asserted at any
            time against Warren and DEVCO, and which arise out of, and are
            directly related to, or are in any manner connected with the
            Partnership's operation of the Fractionator Facility or ownership of
            an interest in the Fractionator Facility, or any portion thereof on
            or after the Effective Date, including, but not limited to:
            obligations assumed by the Partnership under Section 4.7 above; all
            Claims related to breaches or defaults of contracts or agreements;
            Claims for injury or death to persons; Claims for damage to
            property and Claims relating to violations of applicable laws,
            rules, orders, regulations or codes; and any Claims: (a) which arise
            in any way in connection with any Environmental Conditions EXCLUDING
            Claims arising in connection with Environmental Conditions which
            relate to operation of the Fractionator Facility, or any portions
            thereof, prior to the Effective Date; or (b) which are asserted by
            any third persons from and after the Effective Date and which are
            founded upon Warren's interpretation or administration of any of the
            Contracts prior to the Effective Date to the extent such Claims
            relate to monies claimed to be owed, or contractual damages
            asserted, and which are attributable to any accounting periods from
            and after the Effective Date.

            4.8.4. The Partners agree also hereby agree that they shall
            indemnify, hold harmless and defend Warren and DEVCO, their
            respective directors, officers, employees, partners,
            representatives, successors and assigns from and against all Claims
            (including reasonable attorney's fees) resulting from any inaccuracy
            in or breach of their respective representations and warranties
            under this Agreement.

            4.8.5. With respect to all indemnifications contained in this
            Agreement, the indemnifying Party shall have the full authority to
            handle the defense of, and to negotiate, settle or in any other
            manner compromise any Claim for which it is indemnifying the other
            Party; and, so long as the indemnifying Party is conducting that
            defense in a reasonable manner, the indemnitee shall not be entitled
            to claim any legal expenses or costs of defense from the
            indemnifying Party. Provided, however, any settlement or release
            entered into or accepted by the indemnifying Party shall include a
            full release of the indemnified Parties hereunder. It is provided,
            however, that the

                                       19
<Page>

            indemnitee shall have the right to participate in the defense of any
            Claim(s) in which the indemnitee is named, and be represented by
            counsel chosen by the indemnitee, provided that the costs, fees and
            expenses of that participation shall remain the responsibility of
            and shall be borne by the indemnitee. The indemnitee shall only be
            entitled to compensation of costs of defense, including reasonable
            attorneys fees, in the event that the indemnifying Party has failed
            to conduct a reasonable defense of the Claim(s).

      4.9. EXCLUSIVE REMEDY. The remedies set forth in this Article 4 shall
be the Partnership's and the individual Partners' exclusive remedies for any
and all liabilities, costs or expenses, including any violation of any laws,
occurring at or in connection with the Fractionator Facility prior to the
Effective Date and the Closing Date, regardless of when discovered by the
Partnership, either pursuant to this Agreement or pursuant to any other
rights, including (without limitation) any common law rights or any rights
created by or implied from any state or federal statute or regulation.

      4.10. SURVIVAL OF AND SCOPE OF INDEMNITIES. The indemnity provisions of
this Agreement shall survive for a period of four (4) years from the Effective
Date; excluding, however, the Partnership's indemnity given in Section 4.8.3.
above, which shall not expire. Further, the Partnership and the Parties agree
that the indemnities given herein shall not extend to or include to
consequential damages incurred by the indemnified Parties or to punitive damages
which are imposed as a result of the conduct of the indemnitee seeking to
recover such amounts under an indemnity.

5. OTHER AGREEMENTS.

      5.1. PARTNER FRACTIONATION AGREEMENTS. As of the Effective Date, Warren
and Amoco and an affiliate of Amoco, Amoco Oil Company, have also executed
Fractionation Agreements with the Partnership in the forms attached hereto as
Exhibit E.

      5.2. CONVEYANCING DOCUMENTS. After the execution of this Agreement but on
or before the Effective Date of this Agreement, Warren and DEVCO will have
executed and delivered the Conveyancing Documents; consisting of the following:

            5.2.1. The Lease Agreement, in the form attached as Exhibit D;

            5.2.2. Three Assignments and Bills of Sale (all in the form set
            forth in Exhibit F); one from Warren to DEVCO of a two percent (2%)
            undivided interest in and to the Fractionation Facility, one from
            DEVCO to the Partnership of that same 2% interest, and one from
            Warren to the Partnership of a ninety-eight percent (98%) undivided
            interest in and to the Fractionation Facility;

                                       20
<Page>

            5.2.3. One easement, in a form to be agreed to between the Partners,
            Warren and DEVCO, to be for the same term as the term of this
            Agreement, for the purpose of allowing the continued presence of,
            and Partnership access to, all Related Facilities, with terms no
            more burdensome than those set forth for surface use in the Lease
            Agreement.

      5.3. AMOCO PARENT GUARANTY. On or before the Effective Date of this
Agreement, Amoco shall have obtained an original executed guaranty of its
obligations hereunder by its parent company, Amoco Oil Company, substantially in
the form attached hereto as Exhibit H, and delivered same to Warren and DEVCO,
and Warren and DEVCO shall not be obligated to execute their respective
Conveyancing Documents to convey title to the Fractionation Facility into the
Partnership until receipt of same.

      5.4. ASSIGNMENT OF OTHER AGREEMENTS. To the extent that any of the
Contracts can not, by their terms or because of the objection of a party to such
Contract be assigned to the Partnership, Warren will deliver all Raw Product
which it receives pursuant to such Contracts and will fractionate same at the
Fractionation Facility, and will provide the Partnership the beneficial rights,
including without limitation any fee payments to which it might be entitled
under fractionation service agreements, to the Partnership, and the Partnership
agrees to perform and bear the responsibility for all obligations of Warren
under such Contracts.

      5.5. OPERATING AGREEMENT. On the Effective Date, DEVCO, for and on behalf
of the Partnership and in its capacity as the Managing General Partner, and the
Partners, for the limited purposes stated therein, shall execute with Warren the
Operating Agreement.

6. DISTRIBUTIONS.

      6.1. MONTHLY DISTRIBUTIONS. By the thirtieth (3Oth) day following the end
of each Month, the Managing General Partner shall distribute to the Partners and
the Partners shall receive any Distributable Cash based on their respective
Percentage Interests, and subject to any Distributions then in effect pursuant
to Section 3.9.2. Distributions of $50,000 or more shall be made by wire
transfer and payments of less than $50,000 shall be made by check, all to each
Partner in accordance with the individual payment instructions provided by each
Partner to the Managing General Partner.

      6.2. DISTRIBUTIONS ON TERMINATION. Upon termination of the Partnership,
the Partners shall take account of all of the Partnership's Property and
liabilities. Notwithstanding the foregoing provisions of this Section 6, the
proceeds of liquidation of the Property, or Property distributed in kind,
shall be applied and distributed in the following order:

                                       21
<Page>

            6.2.1. PAYMENT OF DEBTS AND ESTABLISHMENT OF RESERVES. To the extent
            permitted by law, the proceeds of the liquidation sales shall be
            paid or distributed as follows:

                  (1) First, to the expenses of liquidation:

                  (2) Second, to the repayment of the debts of the Partnership
            other than debts owing to the Partners;

                  (3) Third, to the establishment of reasonable reserves for
            obligations and contingent liabilities of the Partnership; and

                  (4) Fourth, to the repayment of such debts as are owing to the
            Partners.

            6.2.2. DISTRIBUTIONS TO PARTNERS. All remaining available proceeds
            from dissolution and winding up of the Partnership, shall be
            distributed to all of the Partners in amounts equal to the Partners'
            positive Capital Account balances after adjusting such Capital
            Accounts for all distributions made pursuant to Section 6.1 above
            and all allocations under Article 7 below.

7. ALLOCATIONS TO PARTNERS.

      7.1. IN GENERAL. For purposes of maintaining the Capital Accounts pursuant
to Section 3.10 and for income tax purposes, except as provided in Section 7.2,
7.3 and 7.4, each item of income, gain, loss, deduction and credit of the
Partnership shall be allocated to the Members in accordance with their
Percentage Interests.

      7.2. OTHER TAX ALLOCATIONS. For income tax purposes, income, gain, loss,
and deduction with respect to property contributed to the Partnership by a
Partner or revalued pursuant to Treasury Regulation Section 1.704-1(b)(2)(iv)(f)
shall be allocated among the Partners in a manner that takes into account the
variation between the adjusted tax basis of such property and its book value, as
required by Section 704(c) of the Code and Treasury Regulation Section 1.704-1
(b)(4)(i), using the remedial allocation method permitted by Treasury Regulation
Section 1.704-3(d).

      7.3. SPECIAL ALLOCATIONS. The following special allocations shall be made
in the following order:

            7.3.1. QUALIFIED INCOME OFFSET. In the event any Partner
            unexpectedly receives any adjustments, allocations, or distributions
            described in Section 1.704-1(b)(2)(ii)(d)(4), Section
            1.704-1(b)(2)(ii)(d)(5), or Section 1.704-1(b)(2)(ii)(d)(6) of the
            Treasury Regulations, items of Partnership income and gain shall be
            specially allocated to each such Partner in an amount and manner
            sufficient to

                                       22
<Page>

            eliminate, to the extent required by the Treasury Regulations, the
            Adjusted Capital Account Deficit of such Person as quickly as
            possible, provided that an allocation pursuant to this
            Section 7.3.1. shall be made only if and to the extent that such
            Person would have an Adjusted Capital Account Deficit after all
            other allocations provided for in this Article 7 have been
            tentatively made as if this Section 7.3.1. were not in this
            Agreement.

            7.3.2. GROSS INCOME ALLOCATION. In the event any Partner has an
            Adjusted Capital Account Deficit at the end of any calendar year
            which is in excess of the sum of (i) the amount such Partner is
            obligated to restore pursuant to any provision of this Agreement,
            and (ii) the amount such Partner is deemed to be obligated to
            restore pursuant to the penultimate sentences of Treasury
            Regulations Section 1.704-2(g)(1) and 1.704-2(i)(5), each such
            Partner shall be specially allocated items of Partnership income and
            gain in the amount of such excess as quickly as provided that an
            allocation pursuant to this Section 7.3.2. shall be made possible
            only if and to the extent that such Person would have an Adjusted
            Capital Account Deficit in excess of such sum after all other
            allocations provided for in this Article 7 have been made as if
            Section 7.3.1. hereof and this Section 7.3.2. were not in this
            Agreement.

            7.3.3. SECTION 754 ADJUSTMENT. To the extent an adjustment to the
            adjusted tax basis of any Partnership asset pursuant to Code Section
            734(b) or Code Section 743(b) is required, pursuant to Treasury
            Regulations Section 1.704-1(b)(2)(iv)(m)(2) or Treasury Regulations
            Section 1.704-1(b)(2)(iv)(m)(4), to be taken into account in
            determining Capital Accounts as the result of a distribution to a
            Partner in complete liquidation of its interest in the Partnership,
            the amount of such adjustment to the Capital Accounts shall be
            treated as an item of gain (if the adjustment increases the basis of
            the asset) or loss (if the adjustment decreases such basis) and such
            gain or loss shall be specially allocated to the Partners in
            accordance with their Percentage Interests in the event Treasury
            Regulations Section 1.704-1(b)(2)(iv)(m)(2) applies, or to the
            Partners to whom such distribution was made in the event Treasury
            Regulations Section 1.704-1(b)(2)(iv)(m)(4) applies.

            7.3.4. If a cash Distribution under Section 3.9.2 is made, then
            income will be allocated to the Participating Partners in an amount
            equal to the Distribution.

      7.4. CURATIVE ALLOCATIONS. The allocations set forth in Section 7.3.1.,
7.3.2., and 7.3.3. (the "Regulatory Allocations") are intended to comply with
certain requirements of Treasury Regulations Section 1.704-1(b). Notwithstanding
any other provision of this Article 7

                                       23
<Page>

(other than the Regulatory Allocations), the Regulatory Allocations shall be
taken into account in allocating items of income, gains and loss deduction
among the Partners so that, to the extent possible, the net amount of such
allocations of items of income, gains, and loss deduction and the Regulatory
Allocations to the Partners shall be equal to the net amount that would have
been allocated to them if the Regulatory Allocations had not occurred.
Allocations made pursuant to this Section 7.4 are hereby authorized by the
Management Committee and shall be for the purpose of minimizing the economic
distortions that might otherwise result from the application of the
Regulatory Allocations.

8. MANAGEMENT OF THE PARTNERSHIP.

      8.1. MANAGEMENT COMMITTEE. The business of the Partnership shall be
managed by the Managing General Partner, subject to review and approval of
certain matters by the Management Committee. The Management Committee shall
be comprised of principal representatives appointed by each of the Partners.
For purposes of representation on the Management Committee, each Partner
shall have one representative on the Management Committee. The Management
Committee shall meet at least once during the calendar year and such meetings
will be held to inform the members of the activities of the Partnership and
to act on any matters which require action by the Management Committee
including review and approval of the budgets prepared by the Operator under
the supervision of the Managing General Partner. Each Partner shall bear its
own costs incurred in connection with its representative traveling to and
attending any Management Committee meeting and same shall not be considered a
Partnership expense for which the Partner is entitled to reimbursement from
the Partnership's funds.

      8.2. MEETING NOTICE. The Management Committee shall meet upon five (5)
business Days notice at the call of any Partner to all other Partners. However,
the Managing General Partner shall give all Partners 30 Days minimum advance
notice of the time and place of the annual meeting.

      8.3. VOTING PROCEDURES. The Management Committee may act by vote at a
meeting or without a meeting by written vote. Members of the Management
Committee may participate in a meeting by means of conference telephone or
similar communications equipment by means of which all individuals participating
in the meeting shall constitute presence in person at such meeting. Each
Management Committee representative shall be entitled to a number of votes equal
to its Partner's Percentage Interest at the time of any vote.

      8.4. VOTE REQUIRED. Except as otherwise provided in this Agreement,
approval of any matter by the Management Committee shall require a vote of more
than eighty-eight percent (88%) of the total Percentage Interest of all Partners
entitled to vote.

      8.5. MINUTES. The Management Committee will appoint a secretary who will
be present at and record the minutes of all meetings and promptly provide each
member with copies thereof

                                       24
<Page>

following each meeting. The original of the minutes as approved by each Partner
shall be maintained at the principal office of the Managing General Partner.

      8.6. MATTERS REQUIRING UNANIMOUS APPROVAL. The following items shall
require approval of all members of the Management Committee:

                  (1) Authorize any short term or long term borrowing or other
            debt on behalf of the Partnership, except for trade credit incurred
            by the Operator or the Managing General Partner in the ordinary
            course of business and within their expenditure authorities set
            forth in this Agreement or in the Operating Agreement;

                  (2) Sell, lease, mortgage, pledge, transfer, assign, or
            otherwise encumber or dispose of all or substantially all of the
            Property or merger or combination of the Partnership with or into
            any other Person in one or a series of transactions;

                  (3) Lend money to, or guarantee the obligation of any Person
            on behalf of the Partnership;

                  (4) Make, execute or delivery for the Partnership any
            mortgage, deed of trust or security agreement conveying a security
            interest in any of the Property;

                  (5) Release, compromise or settle any claim against the
            Partnership or in its favor (except upon full satisfaction of claims
            in its favor) in excess of $500,000 or any insurance claim in excess
            of $250,000;

                  (6) Any decision to rebuild or repair any portions of the
            facilities of the Partnership after the occurrence of a casualty
            loss or damage to such facilities if the cost of rebuilding or
            repair equals or exceeds $5,000,000;

                  (7) Require Partners to make any Capital Contributions to the
            Partnership other than their Initial Investments;

                  (8) Cause the Partnership to make any tax elections, decisions
            or allocations other than as necessary to carry into effect the
            express provisions of this Agreement;

                  (9) Institute any judicial or administrative proceedings on
            behalf of any Partners individually or institute any judicial or
            administrative proceedings on behalf of the Partnership where the
            amount in controversy is in excess of $500,000, except to the extent
            expressly authorized under the Operating Agreement;

                                       25
<Page>

                  (10) Terminate the business or dissolve the Partnership or
            appoint a liquidating trustee other than as provided in Article 12;

                  (11) Change the provisions of Exhibit B (Income Tax Matters);

                  (12) Amend this Agreement, the Operating Agreement, the
            Conveyancing Documents or the Partners Fractionation Agreements;

                  (13) Create or dispose of any subsidiary of the Partnership or
            any interest therein;

                  (14) Enter into any material contract or arrangement having a
            term in excess of two (2) years (excluding material master services
            agreements) other than the than Third Party Fractionation
            Agreements, the Conveyancing Documents, Operating Agreement, the
            Partners Fractionation Agreements or any other agreements
            specifically contemplated by this Agreement and intended to be
            effective as of the Effective Date;

                  (15) Enter into any Third Party Fractionation Agreement having
            a term in excess of five (5) years;

                  (16) Except as otherwise provided herein, do or permit or
            suffer to be done any act or thing whereby the Partnership may be
            wound up, liquidated or dissolved (whether voluntarily or
            compulsorily);

                  (17) Change the nature or scope of the Partnership's business
            or commence any new business outside of the scope activities related
            or incidental to the purposes of the Partnership set forth in
            Section 1.5 or outside of the Mont Belvieu Area;

                  (18) Do any act which would make it impossible to accomplish
            the purposes of the Partnership;

                  (19) Change the definition of fiscal year in Section 9.2.

                  (20) Admit any additional partner to the Partnership except
            pursuant to Section 11;

                  (21) Remove or change the Managing General Partner, except as
            provided in Section 8.9;

                  (22) Place or permit any liens to exist on the Property if
            consent for such

                                      26
<Page>

            liens is required under any debt instruments of any Partner or an
            Affiliate of any Partner; and

                  (23) Purchase any insurance for the Partnership or any
            Partner(s) beyond that required by law or that required to be
            maintained by the Operator pursuant to the terms of the Operating
            Agreement.

      8.7. AUTHORITY TO BIND THE PARTNERSHIP. Except as provided in this
Agreement or as expressly authorized by the Management Committee consistent
with this Agreement, no Partner shall have any power or authority to act on
behalf of the Partnership in any manner affecting the Partnership, or to bind
the Partnership, or to represent that it has such power or authority.

      8.8. DUTIES OF MANAGING GENERAL PARTNER. The Managing General Partner
shall supervise and monitor the Operator's performance of its duties pursuant to
the terms of the Operating Agreement and Article 9 below and shall serve as the
Tax Matters Partner and perform generally all managerial duties related to
conducting the ordinary business of the Partnership to the extent same have not
been delegated to the Operator, including filing of any tax returns,
governmental filings, and reports. Certain portions of Article 9 below also
govern the Managing General Partner's performance and authority hereunder to the
extent same expressly so state.

      8.9. CHANGE OF MANAGING GENERAL PARTNER

            8.9.1. RESIGNATION OF MANAGING GENERAL PARTNER. The Managing
            General Partner or any successor may resign effective 180 Days after
            written notice to the Management Committee. A vote of 100% approval
            of all the Partners will be required to select a new Managing
            General Partner. Upon the date the resignation is effective, the
            Managing General Partner shall be relieved of its obligations except
            as otherwise provided in this Agreement.

            8.9.2. REMOVAL OF MANAGING GENERAL PARTNER. The Managing General
            Partner may be removed by the vote of more than eight-eight percent
            (88%) of the Percentage Interest of the Partners if; (1) such
            Managing General Partner breaches any material provision of this
            Agreement and fails or refuses to cure such breach within a
            reasonable time after written notice from the Management Committee
            to do so; or (2) Managing General Partner is placed in bankruptcy or
            receivership or executes an assignment for the benefit of creditors.
            Managing General Partner has the right to demand an arbitration of
            the fairness and reasonableness of any such removal pursuant to the
            dispute resolution provisions of this Agreement. The Partners may,
            by unanimous vote of the Management Committee, elect a successor
            Managing General Partner.

                                       27
<Page>

            8.9.3. SUCCESSOR MANAGING GENERAL PARTNER. Upon the resignation or
            removal of the Managing General Partner, as provided for above, the
            following shall govern:

                  (1) Management Committee shall promptly select a successor in
            accordance with the procedures set forth in such sections. Any
            Partner may submit a bid to the Management Committee to become
            Managing General Partner. Upon notice of resignation or removal of
            any Managing General Partner, said managing General Partner shall
            forthwith deliver to its successor, originals of all books, records,
            accounts, and audits and all other data and information in its and
            its Affiliates' possession relative to this Agreement.

                  (2) In the event of resignation or removal of Managing General
            Partner, such Managing General Partner shall be reimbursed for
            charges, expenditures and liabilities incurred by it for services
            rendered hereunder in accordance with this Agreement, except for
            such charges, expenditures or liabilities which are in dispute, and
            said dispute will be resolved in accordance with the dispute
            provisions of Section 13.

                  (3) Any Party hereto becoming a successor Managing General
            Partner shall thereupon succeed to all duties, powers, obligations,
            rights and authorities conferred upon the Managing General Partner
            herein.

            8.9.4. COMPENSATION TO PARTNERS. Except as otherwise provided in
            this Agreement, all agreements regarding services for which the
            Partners or any Affiliate is to receive compensation from the
            Partnership or with respect to partnership activities shall be
            embodied in written contracts which precisely describe the services
            to be rendered and all compensation to be paid and which are
            approved by the Management Committee.

      8.10. DUTIES OF GENERAL PARTNERS AND OTHERS CONTROLLING GENERAL PARTNERS.
To the extent that, at law or in equity, any Partner, or any employee, agent or
representative of same, has duties (including fiduciary duties) and liabilities
relating thereto to the Partnership or to the Partners, the General Partners and
any other Person acting in connection with the Partnership's business or
affairs, they shall not be liable to the Partnership or to any Partner for their
good faith reliance on the provisions of this Agreement. The provisions of this
Agreement, to the extent that they restrict the duties and liabilities of any
such Person otherwise existing at law or in equity, are agreed by the Partners
to replace such other duties and liabilities of such Persons

9. OPERATION OF THE FACILITY.

      9.1. GENERAL. Subject to the provisions of the Operating Agreement,
Operator shall

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<Page>

have the exclusive right to operate the Facility, supervise construction of all
modifications to the Facility and negotiate agreements with third parties
related to the operation of the Partnership business; including, without
limitation, for the provision of processing or fractionating services, all
strictly in the manner set forth in the Operating Agreement. The Operating
Agreement shall also govern removal and resignation of the Operator.

      9.2. Fiscal Year. The fiscal year of the Partnership shall be the calendar
year.

      9.3. CHANGE OF OPERATOR. The Partners may, by unanimous vote of the
Management Committee, direct the Managing General Partner to select a successor
Operator and direct the Managing General Partner to terminate the Operating
Agreement with the then current Operator, provided same is a termination allowed
under the terms of the Operating Agreement. Once a successor Operator is
selected by the Managing General Partner, such successor Operator and the new
Operating Agreement proposed to be executed with such successor shall be
submitted by the Managing General Partner to the Management Committee for
approval.

      9.4. RESIGNATION OF OPERATOR. Operator or any successor may resign
effective 180 Days after written notice to the Management Committee. A vote of
100% approval of all the Partners will be required to select a new Operator.
Upon the date the resignation is effective, the Operator shall be relieved of
its obligations except as otherwise provided in the Operating Agreement.

      9.5. REMOVAL OF OPERATOR . Operator may be removed by a vote of more than
fifty percent (50%) (based an Percentage Interests held) of the Management
Committee representatives other than those to whom the Operator is an Affiliate
if; the Operator is then in breach of the terms of the Operating Agreement and
the Partnership has the right to terminate same pursuant to Section 9.3 of the
Operating Agreement.

      9.6. SUCCESSOR OPERATOR. Upon the resignation or removal of the Operator,
as provided for in any of the above Sections 9.3, 9.4 and 9.5, the following
shall govern:

                        (i) Management Committee shall promptly select a
                  successor in accordance with the procedures set forth in such
                  sections. Any Partner may submit a bid from it or one of its
                  Affiliates to the Management Committee to operate the
                  Facility. Upon notice of resignation or removal of any
                  Operator, said Operator shall forthwith deliver to its
                  successor, originals of all books, records, accounts, and
                  audits and all other data and information in its and its
                  Affiliates' possession relative to the Operating Agreement.

                        (ii) In the event of resignation or removal of Operator,
                  such Operator shall be reimbursed for charges, expenditures
                  and liabilities

                                     29
<Page>

                  incurred by it for services rendered hereunder in accordance
                  with the Operating Agreement, except for such charges,
                  expenditures or liabilities which are in dispute, and said
                  dispute will be settled in a timely manner.

                        (iii) Any party hereto becoming a successor Operator
                  shall thereupon succeed to all duties, powers, obligations,
                  rights and authorities conferred upon the Operator in the
                  newly executed Operating Agreement and herein with regard to
                  the operation of the Facility.

      9.7. TRANSACTIONS WITH AFFILIATES. Notwithstanding any other provisions of
this Agreement, the following provisions and restrictions shall govern with
respect to any transactions between the Partnership and the Partners or their
Affiliates:

            9.7.1. ACQUIRING ASSETS. The Partnership shall not acquire any
            property or assets from a Partner or any Affiliate of a Partner,
            except as to the Operator to the extent allowed pursuant to the
            terms of Exhibit A (Accounting Procedure), unless the terms of the
            transaction are approved by a majority of all the other Partners.

            9.7.2. TRANSFERRING ASSETS. The Partnership shall not transfer any
            asset to a Partner or any Affiliate of a Partner except pursuant to
            Section 9 herein or Exhibit A.

            9.7.3. CONTRACTS WITH AFFILIATES. The Partnership shall be entitled
            to engage in any transaction related to its business with the
            Partners or Affiliates of the Partners, provided that Partners
            owning a majority of all Percentage Interests held by disinterested
            Partners (i.e., those who are not directly or through any of their
            Affiliates a party to the transaction being reviewed) shall approve
            the terms, conditions and fees for such services or transactions.

            9.7.4. COMPENSATION TO PARTNERS. Except as otherwise provided in
            this Agreement, all agreements regarding services for which the
            Partners or any Affiliate is to receive compensation from the
            Partnership or with respect to partnership activities shall be
            embodied in written contracts which precisely describe the services
            to be rendered and all compensation to be paid.

10. INDEMNITIES AND INSURANCE.

      10.1. DEFINITIONS. For the purposes of this Section 10, "Partner",
"Partnership", "Operator" and "Affiliate" will be deemed to include their
respective officers, directors, agents and employees.

                                      30
<Page>

      10.2. OBLIGATIONS OF PARTNER. No Partner shall be held individually
responsible or liable for damage arising out of:

            10.2.1. Breach of this Agreement by another Partner;

            10.2.2. Misrepresentation by another Partner;

            10.2.3. Anything done or omitted to be done through the gross
            negligence or willful misconduct of another Partner.

            10.2.4. Any activity engaged in by another Partner outside the
            ordinary course of the business of the Partnership.

To the extent that a Partner's conduct falls within the list herein enumerated,
that Partner agrees to indemnify and hold harmless and defend each of the other
Partners and their Affiliates and the Partnership from and against all claims,
loss, damage, demand, liability, obligations, or rights of actions on account
thereof.

      10.3. INDEMNITY TO MANAGING GENERAL PARTNER NOTWITHSTANDING ANYTHING IN
THIS AGREEMENT TO THE CONTRARY, THE PARTNERSHIP AND EACH PARTNER, AS TO ITS
PERCENTAGE INTEREST IN THE PARTNERSHIP, HEREBY SPECIFICALLY AGREES THAT MANAGING
GENERAL PARTNER SHALL NOT BE LIABLE FOR, AND RELEASES MANAGING GENERAL PARTNER
FROM AND AGREES TO INDEMNIFY AND HOLD HARMLESS MANAGING GENERAL PARTNER FROM
AND AGAINST ANY AND ALL CLAIMS, WHETHER FINANCIAL OR OTHERWISE, IN ANY WAY
ARISING OUT OF, IN CONNECTION WITH, OR INCIDENT TO THE OPERATION OF THE
FACILITY, INCLUDING, BUT NOT LIMITED TO, (I) ANY VIOLATION OR ALLEGED VIOLATION
OF ANY APPLICABLE LAWS, INCLUDING ENVIRONMENTAL LAWS; (II) ANY INJURY TO OR
DEATH OF ANY PERSONS OR LOSS OF ANY PROPERTY; AND (III) ALL CLAIMS ARISING OUT
OF ANY CONTRACTS OR AGREEMENTS, INCLUDING BUT NOT LIMITED TO INDEMNITY
OBLIGATIONS ASSUMED BY THE MANAGING GENERAL PARTNER. IN ALL CASES DESCRIBED
ABOVE, THE PARTNERSHIP'S AND EACH PARTNER'S OBLIGATION TO INDEMNIFY AND HOLD THE
MANAGING GENERAL PARTNER HARMLESS SHALL APPLY WHETHER OR NOT ANY SUCH CLAIMS
SHALL ARISE IN WHOLE OR IN PART FROM ANY SOLE, JOINT OR CONCURRENT FAULT OR
NEGLIGENCE OF THE MANAGING GENERAL PARTNER, OR ANY OF ITS CONTRACTORS, PROVIDED,
HOWEVER, THAT THE PARTNERSHIP AND EACH PARTNER SHALL NOT BE REQUIRED TO RELEASE,
INDEMNIFY OR HOLD HARMLESS THE MANAGING GENERAL PARTNER FROM ANY CLAIMS ARISING
OUT OF, ATTRIBUTABLE TO, IN CONNECTION WITH OR INCIDENT TO ANY GROSS

                                     31
<Page>

NEGLIGENCE, FRAUD OR WILLFUL MISCONDUCT OF THE MANAGING GENERAL PARTNER, THE
OPERATOR OR THEIR RESPECTIVE CONTRACTORS. THE FOREGOING RELEASE AND INDEMNITY
APPLIES TO ACTS OR OMISSIONS OF THE MANAGING GENERAL PARTNER WITH RESPECT TO
BUSINESS DECISIONS PERTAINING TO THE FACILITY.

      10.4. INSURANCE. Each Partner shall maintain its own insurance against its
portion of the risks attendant to the ownership and operation of the Property.
Each Partner shall maintain, at such Partner's expense, at all times during the
term of this Agreement the insurance coverage set forth below with companies
satisfactory to the Management Committee with full policy limits applying, but
not less than, as stated. The minimum insurance coverage shall be as follows:

            (a)   Auto Liability, including employer's non-owned coverage, with
                  minimum limits of $1,000,000:

            (b)   General Liability coverage with minimum limits of $1,000,000
                  bodily injury and property damage each and in the aggregate to
                  include broad form property damage coverage;

            (c)   Umbrella Liability coverage with limits of at least
                  $5,000,000; and

            (d)   Property loss coverage in an amount equal to a percentage of
                  the replacement value of the Property equal to such Partner's
                  Percentage Interest.

Each policy shall be endorsed to provide waiver of subrogation rights in favor
of the Partnership and each Partner. Each Partner agrees to contribute to the
Partnership proceeds of its insurance to pay any losses of the Partnership that
would have been covered had the Partnership maintained its own policies of that
same type and coverage. Each Partner may self-insure as to the risks that would
otherwise be covered by the above types of coverage, but shall be obligated to
pay and contribute to the Partnership amounts that would have been payable under
industry standard form policies for such coverages up to the amounts set forth
above. Provided, however, no Partner shall be obligated to pay insurance
proceeds or contribute to the Partnership any amounts as to casualty losses
within the scope of Section 8.6.6 above unless and until the Management
Committee approves the rebuilding or repair of the effected portions of the
facilities.

      10.5. POLICY REQUIREMENTS. With respect to the insurance obtained by the
Partners as provided in Section 10.4 above, such insurance shall include the
following:

            (a)   A requirement that the insurer provide the Partnership with
                  thirty (30) days written notice prior to the effective date of
                  any cancellation of or material change to any such insurance;

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<Page>

            (b)   Each such insurance policy shall name the Partnership and each
                  Partner as additional insureds with respect to the operation
                  of the Facility and shall be primary to and not in excess of
                  or contributory with any other insurance available to the
                  Partnership or each Partner.

      10.6. THIRD PARTIES. It is not the intention of the Partners to release
from liability any third party with whom the Managing General Partner
contracts for the performance of the carrying out of its obligations in terms
of this Agreement. The provisions of this Article 10 are not made for the
benefit of any person or entity other than the Partnership, the Partners and
their Affiliates.

      10.7. Notice. The indemnified Party shall promptly give notice to the
indemnifying Party of any CLAIMS loss, damage, demands, liabilities, obligations
or rights of action for which such Party seeks indemnity.

11. TRANSFERABILITY OF PERCENTAGE INTERESTS.

      11.1. TRANSFERS TO AFFILIATES. A Partner may, at any time upon written
notice to the Partnership, transfer all or any part of its Percentage Interest
to any Affiliate or Affiliates. After complying with the requirements of Section
11.5, any Affiliate transferee shall automatically become a Partner in
accordance with the provisions of this Agreement without any requirement of an
affirmative vote by the other Partners.

      11.2. TRANSFERS TO PARTIES OTHER THAN AFFILIATES. Subject to the Partners'
Right of First Refusal contained in Section 11.3, a Partner may transfer all or
any part of its total Percentage Interest to one or more parties other than
Affiliates upon receiving the written consent to that transfer from all of the
other Partners. The other Partners agree that they will not unreasonably
withhold written consent to any such transfer. After complying with the
requirements of Section 11.5, each transferee shall thereafter be a Partner for
all purposes of this Agreement.

      11.3. RIGHT OF FIRST REFUSAL. If a Partner desires to dispose of all or
some of its Percentage Interest in the Partnership ("Transferring Partner") to a
non-Affiliate, then it may do so after first offering the interest to the other
Partners who hold Partnership interests of the same class as the one to be
transferred ("Qualified Partners"), and such Qualified Partners shall have a
preferential right to purchase such interest on the same terms offered by a bona
fide purchaser ready and able to purchase. The Transferring Partner shall give
written notice to the Qualified Partners, at least 45 Days prior to the
effective date of such disposition, specifying the interest, the price and terms
of sale, the identity of the proposed purchaser and attaching a good faith
letter of intent between the Transferring Partner and the proposed purchaser
containing the material terms and conditions of the sale. Each of the Qualified
Partners shall have a period of 60 Days after the receipt of the notice to
exercise its option to purchase the interest on the terms and conditions set
forth in the letter of intent or similar

                                     33
<Page>

document. If any of the Qualified Partners wishes to exercise its option under
this Section it shall do so by giving written notice to the Transferring Partner
and each of the other Partners within the 60-Day period. If more than one of the
Qualified Partners exercises their options under this Section, the Percentage
Interest being transferred shall be divided and sold to each of the exercising
Qualified Partners in shares proportional to each such Qualified Partner's
Percentage Interest. If the Transferring Partner has not completed said sale
within 120 Days following the expiration of the 60 Day period, then the
preferential rights of the Qualified Partners shall be considered as revived and
the interest shall have to be re-offered to the Qualified Partners by the
Transferring Partner in accordance with this Section. The rights granted to
Partners under this Section shall apply to each and every transfer of all or any
portion of any Percentage Interests other than to Affiliates of a Partner, and
such rights shall apply regardless of whether prior conveyances of that same or
other Percentage Interests have occurred without any Partners exercising their
preferential rights hereunder and these rights shall not be deemed waived as to
Percentage Interests held by new Partners or transferees of any of the original
Partners due to the other Partner or Partners failing to exercise same as to any
prior transfers, including the transfer to such new Partner or transferee.

      11.4. CHANGES IN CONTROL. A change in the ultimate parent company of a
Partner, or the merger or sale thereof to a previously unrelated third party,
shall not be considered a transfer of the Percentage Interest by the affected
Partner and the other Partner's rights under Section 11.3 above shall not be
considered to be activated or applicable.

      11.5. GENERAL CONDITIONS OF TRANSFERS. Every transfer, assignment or other
disposition of all or any part of a Partner's Percentage Interest under any
provision of this Agreement shall be conditioned upon its being effective only
when the party receiving that Percentage Interest agrees in writing to be bound
by this Agreement and to assume all obligations, liabilities and duties with
respect to that Percentage Interest to which the prior holder was bound and that
the transfer, assignment or other disposition shall be conditioned in the case
of a transfer to an Affiliate that the transferor shall remain responsible, as a
guarantor, for compliance by the transferee with the requirements of this
Agreement.

      11.6. Notwithstanding anything to the contrary herein contained, no
Partner shall be permitted to transfer all or any portion of his interests
(except involuntary to his personal representative by operation of law) if in
the opinion of the tax advisors normally employed by the Partnership, it is more
likely than not that such transfer will terminate the Partnership for federal
income tax purposes under Code Section 708(b)(1)(B). Any Partner proposing to
make a transfer otherwise permitted under this Agreement of all or any portion
of its Percentage Interest shall give notice of the proposed transfer to the
Partnership at least forty-five (45) business days prior to the time of the
proposed transfer. If, within such period, the Partnership does not obtain and
deliver such an opinion to the Partner proposing to make such transfer, the
proposed transfer may be consummated in the manner described in the
aforementioned notice to the Partnership. Any attempted transfer in violation of
the conditions set forth herein shall be null and void AB INITIO and

                                     34
<Page>

the Partner making or attempting to make such a prohibited transfer shall
indemnify and hold the Partnership and each other Partner wholly and
completely harmless from any cost, liability, or damage (including any
increase in their respective federal and state tax liabilities) resulting
therefrom.

12. WINDING UP AND TERMINATION OF THE PARTNERSHIP.

      12.1. EVENTS REQUIRING WINDING UP. The Partnership shall be wound up and
terminated upon the earliest of the following events:

            12.1.1. The expiration of the Term pursuant to the terms of Section
            1.6; or

            12.1.2. The written demand of one or more Partners controlling
            ninety percent (90%) or more of the Percentage Interests;

            12.1.3. Upon the removal, withdrawal, bankruptcy, insolvency, or
            dissolution of a Partner unless, at the time, there are at least two
            other Partners; or

            12.1.4. Sale or other disposition of all or substantially all of the
            Property;

            12.1.5. Entry of an order of judicial dissolution under the Act;

            12.1.6. Failure of any Partner to deliver or cause to be delivered
            its Initial Investment within fifteen (15) days after the Effective
            Date.

      12.2. PARTNER'S PURCHASE OF PROPERTY. The Partners or any Affiliate may
bid in any open bidding process held by a liquidator and, if its bid is
determined to be the best, it may purchase any of the Property upon
dissolution. The liquidator shall notify each Partner in writing of any
offers it receives to purchase any of the Property. Each Partner shall have
the right to purchase any Partnership Property for the same price and on the
same terms and conditions offered in writing by any third party and which are
acceptable to the liquidator in preference to such third party. The
preferential purchase rights available to the Partners shall be exercised by
written election delivered to the liquidator within thirty (30) business days
after such Partner has received notice of the offer and the failure to
respond to a notice of a third party offer shall be deemed a waiver of the
rights under this Section 12.2.

      12.3. TIME OF LIQUIDATION. A reasonable time shall be allowed for the
orderly liquidation of the Property and the discharge of liabilities to
creditors so as to enable the Partners to minimize the normal losses
attendant upon a liquidation.

      12.4. NO LIABILITY FOR RETURN OF CAPITAL. No Partner shall be personally
liable for the return of all or any part of the contributions of any other
Partner to the Partnership. Any such

                                       35
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return shall be made solely from the Partnership Property.

      12.5. LIQUIDATION PROCEDURE.

            12.5.1. Liquidation, winding up and termination of the Partnership
            will commence upon dissolution and be conducted and supervised by
            the Managing General Partner, unless dissolution is brought about by
            an event referred to in Section 12.1.3 where the Partner involved is
            the Managing General Partner, in which case liquidation, winding up
            and termination shall be conducted and supervised by a liquidating
            trustee approved by all the remaining Partners, or by a liquidating
            trustee selected by the all of the members of the Management
            Committee. It is expressly recognized that the General Partner, in
            conducting a liquidation, winding-up and termination of the
            Partnership under this Section, shall be entitled to sell all or any
            part of the Property to itself or to a Limited Partner in accordance
            with Section 12.2, except to the extent all the Partners agree to
            distribute some or all of the Property to one or more Limited
            Partners. The General Partner or other liquidating trustee in
            exercising is obligations under this Section will have all rights
            and powers with respect to the Property and liabilities of the
            Partnership, including the right to transfer such Property and
            settle liabilities and will proceed with reasonable promptness to
            liquidate the Partnership.

            12.5.2. Dissolution of the Partnership shall be effective on the Day
            on which the event occurs giving rise to the dissolution, but the
            Partnership shall not terminate until the Certificate of Limited
            Partnership filed under the Act shall have been canceled and the
            Property shall have been distributed as provided in this Section.
            Notwithstanding the dissolution of the Partnership prior to the
            termination of the Partnership, the business of the Partnership, as
            such, shall continue to be governed by this Agreement. Upon
            dissolution, the Managing General Partner or, if there is none, the
            liquidating trustee approved by all of the members of the Management
            Committee shall liquidate the Property through one or more sales by
            or on behalf of the Partnership under this Section, apply and
            distribute the proceeds from such sales and distribute the Property
            as provided in Section 12.6, and cause the cancellation of the
            Partnerships Certificate of Limited Partnership.

      12.6. NEGATIVE CAPITAL ACCOUNT BALANCES. No Partner shall have any
obligation to restore any negative balance in its Capital Account upon
liquidation of the Partnership.

13. ALTERNATIVE DISPUTE RESOLUTION

      (a) COVERED DISPUTES - Any dispute, controversy or claim (whether
sounding in contract, tort or otherwise) arising out of or relating to this
Agreement, including, without limitation, the meaning of its provisions, or
the proper performance of any of its terms by either Party, its breach,

                                        36
<Page>

termination or invalidity ("Dispute") will be resolved in accordance with the
procedures specified in this Section, which will be the sole and exclusive
procedure for the resolution of any such Dispute, except that a Party,
without prejudice to the following procedures, may file a complaint to seek
preliminary injunctive or other provisional judicial relief, if in its sole
judgment, that action is necessary to avoid irreparable damage or to preserve
the status quo. Despite the filing of any such injunctive or other
provisional judicial relief, the Parties will continue, subject to Subsection
(j) below, to participate in the applicable procedures specified in this
Section. The obligation to participate in such applicable procedures shall
not require either Party to participate in the negotiation between executives
procedures set forth in Subsection (c) below or the mediation procedures set
forth in Subsection (d) below if either Party determines, in its sole
discretion, that such procedures would be futile.

      (b) INITIATION OF PROCEDURES. Either Party desiring to initiate the
dispute resolution procedures set forth in this Section with respect to a
Dispute not resolved in the ordinary course of business (the "Initiating
Party") must give written notice of the Dispute (the "Dispute Notice") to
the other Party (the "Non-Initiating Party"). The Dispute Notice shall
include (i) a statement of that Party's position and a summary of arguments
supporting that position, and (ii) the name and title of the executive who
will represent that Party, and of any other person who will accompany the
executive, in the negotiations under Subsection (c) below.

      (c) NEGOTIATION BETWEEN EXECUTIVES - If one Party has given a Dispute
Notice under Subsection (b) above, the Parties may attempt in good faith to
resolve the Dispute within forty-five (45) days following receipt of the
Dispute Notice by the Non-Initiating Party by negotiation between executives
who have authority to settle the Dispute and who are at a higher level of
management than the persons with direct responsibility for administration of
this Agreement or the matter in Dispute. Within fifteen (15) days after
receipt of the Dispute Notice, the Non-Initiating Party may submit to the
other a written response. If given, the response will include (i) a statement
of that Party's position and a summary of arguments supporting that position,
and (ii) the name and title of the executive who will represent that Party
and of any other person who will accompany the executive. If such a response
is given by the Non-Initiating Party, within forty-five (45) days following
receipt of the Dispute Notice by the Non-Initiating Party, the executives of
both Parties will meet at a mutually acceptable time and place, and
thereafter, as often as they reasonably deem necessary, to attempt to resolve
the Dispute.

      (d) MEDIATION - If the Dispute has not been resolved by negotiation under
the Subsection (c) above within forty-five (45) days following receipt of the
Dispute Notice by the Non-Initiating Party or if the Non-Initiating Party fails
to respond within the required fifteen (15) day period, either Party may
initiate the mediation procedure of this Subsection by giving written notice to
the other Party ("Mediation Notice"). The Parties will endeavor to settle the
Dispute by mediation within sixty (60) days of the Mediation Notice under the
then current Center for Public Resources ("CPR") Model Mediation Procedure for
Business Disputes. If the Parties have not agreed upon a mediator within

                                        37
<Page>

seven (7) days after the Mediation Notice, either Party may request CPR
assistance in the selection of a mediator under its guidelines. Unless
otherwise agreed to by the Parties, no discovery shall be allowed during the
sixty (60) day mediation period. If both Parties elect to participate in the
mediation procedures set forth herein, the cost of the mediator will be
shared equally between the Parties, unless otherwise agreed to in writing by
the Parties. If one Party elects not to participate in the mediation
procedures, neither Party shall bear any cost associated with such procedure,
other than costs that each Party may have incurred in connection therewith
which shall be borne by the Party that incurred such costs.

      (e) ARBITRATION. If the Dispute has not been resolved by mediation
under the Subsection (d) above within the required sixty (60) day period or
if either Party fails and/or refuses to participate in such mediation
procedures, either Party may request that the matter be resolved through
arbitration by submitting a written notice (the "Arbitration Notice") to the
other. Any arbitration that is conducted hereunder shall be governed by the
Federal Arbitration Act, 9 U.S.C. Section 1 ET SEQ., as amended, and will not
be governed by the arbitration acts, statutes, or rules of any other
jurisdiction.

      (f) ARBITRATION PROCEDURE. The Arbitration Notice shall name the
noticing Party's arbitrator and shall contain a statement of the issue(s)
presented for arbitration. Within fifteen (15) Days of receipt of an
Arbitration Notice, the other Party shall name its arbitrator by written
notice to the other and may designate any additional issue(s) for
arbitration. The two named arbitrators shall select the third arbitrator
within fifteen (15) Days after the date on which the second arbitrator was
named. Should the two arbitrators fail to agree on the selection of the third
arbitrator, either Party shall be entitled to request the Senior Judge of the
United States District Court for the Southern District of Texas to select the
third arbitrator. Should either Party fail and/or refuse to name its
arbitrator within the required fifteen (15) day period, the other Party shall
be entitled to request the Senior Judge of the United States District Court
for the Southern District of Texas to select the arbitrator for such Party.
All arbitrators shall be qualified by education or experience within the
natural gas liquids portion of the energy industry to decide the issues
presented for arbitration. No arbitrator shall be: a current or former
director, officer, or employee of either Party or its Affiliates; an attorney
(or member of a law firm) who has rendered legal services to either Party or
its Affiliates within the preceding three Years; or an owner of any of the
common stock of either Party, or its Affiliates.

      (g) ARBITRATION HEARING. The three arbitrators shall commence the
arbitration proceedings within twenty-five (25) Days following the
appointment of the third arbitrator. The arbitration proceedings shall be
held at a mutually acceptable site and if the Parties are unable to agree on
a site, the arbitrators shall select the site. The arbitrators shall have the
authority to establish rules and procedures governing the arbitration
proceedings, including, without limitation, rules concerning discovery. Each
Party shall have the opportunity to present its evidence at the hearing. The
arbitrators may call for the submission of pre-hearing statements of position
and legal authority, but no post-hearing briefs shall be submitted. The
arbitration panel shall not have the authority to award

                                        38
<Page>

incidental, consequential, special, punitive or exemplary damages. In
addition, if an issue under consideration is limited to a determination of an
amount of money owed by one Party to the other, each Party shall submit to
the arbitration panel a final offer of its proposed resolution of the
dispute. The arbitration panel shall be charged to select from the two
proposals the one which the panel finds to be the most reasonable and
consistent with the terms and conditions of this Agreement, and the
arbitration panel shall not average the Parties' proposals or otherwise craft
its own remedy. All evidence submitted in an arbitration proceeding,
transcripts of such proceedings, and all documents submitted by the Parties
in an arbitration proceeding shall be kept confidential and shall not be
disclosed to any third Party by either Party hereto.

      (h) ARBITRATION DECISION AND COSTS. The decision of the arbitrators or
a majority of them, shall be in writing and shall be final and binding upon
the Parties as to the issue(s) submitted. The cost of the hearing shall be
shared equally by the Parties, and each Party shall be responsible for its
own expenses and those of its counsel or other representatives. Each Party
hereby irrevocably waives, to the fullest extent permitted by law, any
objection it may have to the arbitrability of any such disputes,
controversies or claims and further agrees that a final determination in any
such arbitration proceeding shall be conclusive and binding upon each Party.

      (i) ENFORCEMENT OF AWARD. Judgment upon any award rendered by the
arbitrators may be entered in any court having jurisdiction. The prevailing
Party shall be entitled to reasonable attorneys' fees in any contested court
proceeding brought to enforce or collect any award of judgment rendered by
the arbitrators.

      (j) TOLLING AND PERFORMANCE. Except as otherwise provided in this
Article 13, all applicable statutes of limitation and defenses based upon the
passage of time and all contractual limitation periods specified in this
Agreement, if any, will be tolled while the procedures specified in this
Article 13 are pending. The Parties will take all actions to effectuate
necessary to effectuate the tolling of any applicable statute of limitation
or contractual limitation periods. All deadlines specified herein may be
extended by mutual written agreement of the Parties. Each Party is required
to continue to perform its obligations under this Agreement pending final
resolution of any Dispute, unless to do so would be impossible or
impracticable under the circumstances. Notwithstanding the foregoing, the
statute of limitations of the State of Texas applicable to the commencement
of a lawsuit will apply to the commencement of an arbitration under this
Agreement, except that no defenses will be available based upon the passage
of time during any negotiation or mediation called for by the preceding
Subsections of this Section.

14. GENERAL PROVISIONS.

      14.1. NOTICES. Except as otherwise provided herein, any notice, offer,
request, instruction, correspondence or other communication which shall be
given to any Partner in connection with the business of this Partnership
shall be duly given if and when reduced to writing and delivered

                                        39
<Page>

personally or mailed by registered or certified mail, postage prepaid and
return receipt requested, or facsimile to the Partner's address indicated
below:

                FOR GENERAL PARTNER:

                To:                DOWNSTREAM ENERGY VENTURES CO., L.L.C.
                Attention:         Vice President, Asset Marketing and Services
                At:                1000 Louisiana, Suite 5800
                                   Houston, Texas 77002
                Phone:             (713) 507-3843
                Facsimile:         (713) 767-8286

                FOR AMOCO LIMITED PARTNER:

                To:                Amoco MB Fractionation Company
                Attention:         Manager, NGL Planning and Optimization
                                   Mail Code 1102
                At:                200 East Randolph Drive
                                   Chicago, Illinois 60601
                or:                P.0. Box 87707
                                   Chicago, Illinois 60681-0707

                Phone:             (312) 856-6730
                FAX:               (312) 616-0624

                FOR WARREN LIMITED PARTNER:

                To:                WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP
                Attention:         Vice President, Asset Marketing and Services
                At:                1000 Louisiana, Suite 5800
                                   Houston, Texas 77002
                Phone:             (713) 507-3843
                Facsimile:         (713) 767-8286

or at such other address as a Partner shall designate by written notice to
the others. A notice sent by facsimile shall be deemed to have been receive
by the close of the first Business Day following the Day on which it was
transmitted and confirmed by transmission report or such earlier time as
confirmed orally or in writing by the receiving Party. Notice by U. S. Mail,
whether by U. S. Express Mail, registered mail or certified mail, or by
overnight courier shall

                                       40
<Page>

      be deemed to have been received by the close of the second Business Day
      after the Day upon which its was sent, or such earlier time as is
      confirmed orally or in writing by the receiving Party. Any Partner may
      change its address or facsimile number by giving notice of such change in
      accordance with this provision.

      14.2. SURVIVAL OF RIGHTS. This Agreement shall be binding upon and
inure to the benefit of the Partners and their authorized successors and
assigns.

      14.3. AMENDMENT AND WAIVER. This Agreement may be amended only by a
written agreement executed by all of the Partners. No waiver by either Party
of any default under this Agreement shall be deemed to be a waiver of any
future default, whether of a like or a different character. No waiver shall
be effective unless made in writing and signed by the Party to be charged
with such wavier.

      14.4. AGREEMENT IN COUNTERPARTS. This Agreement, or any amendment
thereto, may be executed in multiple counterparts, each of which shall be
deemed an original Agreement.

      14.5. GOVERNING LAW. THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF
THE PARTIES HEREUNDER SHALL BE GOVERNED BY AND INTERPRETED, CONSTRUED AND
ENFORCED IN ACCORDANCE WITH THE LAWS OF THE STATE OF DELAWARE, EXCLUDING ANY
CONFLICT-OF-LAWS RULE OR PRINCIPLE THAT MIGHT REFER THE GOVERNANCE OR THE
CONSTRUCTION OF THIS AGREEMENT TO THE LAW OF ANOTHER JURISDICTION.

      14.6. ADDITIONAL DOCUMENTS. Each Partner, upon the request of the other
Partners, agrees to perform any further acts and execute and deliver any
documents which may be reasonably necessary to carry out the provisions of
this Agreement.

      14.7. SEVERABILITY. This Agreement and the operations hereunder shall
be subject to the valid and applicable federal and state laws and the valid
and applicable orders, laws, local ordinances, rules, and regulations of any
local, state or federal authority having jurisdiction, but nothing contained
herein shall be construed as a waiver of any right to question or contest any
such order, laws, rules, or regulations in any forum having jurisdiction in
the premises. If any provision of this Agreement is held to be illegal,
invalid, or unenforceable under the present or future laws effective during
the term of this Agreement, (i) such provision will be fully severable, (ii)
this Agreement will be construed and enforced as if such illegal, invalid, or
unenforceable provision had never comprised a part of this Agreement, and
(iii) the remaining provisions of this Agreement will remain in full force
and effect and will not be affected by the illegal, invalid, or unenforceable
provision or by its severance from this Agreement. Furthermore, in lieu of
such illegal, invalid, or unenforceable provision, there will be
added automatically as a part of this Agreement a provision similar in terms
to such illegal, invalid, or unenforceable provision as may be possible and
as may be legal, valid, and enforceable. If a

                                       41
<Page>

provision of this Agreement is or becomes illegal, invalid, or unenforceable
in any jurisdiction, the foregoing event shall not affect the validity or
enforceability in that jurisdiction of any other provision of this Agreement
nor the validity or enforceability in other jurisdictions of that or any
other provision of this Agreement.

      14.8. SECTIONS, EXHIBITS AND SCHEDULES. All exhibits and schedules or
descriptions referred to in this Agreement are expressly incorporated herein
by reference as if set forth in full, whether or not attached hereto. All
references to "Articles," "Sections" and "Exhibits" in this Agreement shall
be construed to be references to the Sections, Article, and Exhibits
comprising this Agreement or which are attached hereto, unless otherwise
specifically stated to the contrary.

      14.9. ATTORNEYS' FEES. In the event litigation is commenced to enforce
any of the provisions of this Agreement, to recover damages for breach of any
of the provisions of this Agreement, or to obtain declaratory relief in
connection with any of the provisions of this Agreement, the prevailing Party
shall be entitled to recover reasonable attorneys' fees and costs if such
action proceeds to judgment. Under no circumstances, however, shall any
Partner or its Affiliates be liable for consequential or punitive damages
arising for a breach of this Agreement.

      14.10. POWER OF ATTORNEY.

            14.10.1. MANAGING GENERAL PARTNER. Each Limited Partner hereby
            constitutes and appoints the Managing General Partner as its true
            and lawful agent and attorney-in-fact, with full power of
            substitution, to make, execute, sign, acknowledge and file in its
            name, place and stead;

                  (1) Any certificate or instrument that may be required or
            appropriate to be filed by the Partnership in order to qualify the
            Partnership to do business as a Partnership in any other state;

                  (2) Any and all amendments or modifications of the instruments
            described in (1) immediately above; and

                  (3) All documents or instruments that may be required or
            appropriate to effectuate the continuation of the Partnership
            (including tax returns and reports, subject to the provisions of
            Section 8) or the dissolution and termination of the Partnership, as
            from time to time amended, all in accordance with the terms of this
            Agreement.

            14.10.2. OPERATOR. Each Limited Partner hereby expressly agrees that
            in accordance with its appointment of the Managing General Partner
            as its attorney-in-fact under the terms of Section 14.10, with full
            power of substitution, that the

                                       42
<Page>

            Managing General Partner may in turn appoint the Operator as its
            substitute to make, execute, and sign any contracts or agreements
            for and on behalf of the Partnership that the Operator is authorized
            to make and enter into under the terms of this Agreement and the
            Operating Agreement.

            14.10.3. DURATION. The foregoing power of attorney of each Limited
            Partner shall be irrevocable, and it shall survive and shall not be
            affected by the subsequent dissolution, bankruptcy or termination of
            any Limited Partner, and it shall extend to such Limited Partner's
            permitted successors and assigns. Each Limited Partner hereby waives
            any and all defenses that may be available to contest, negate or
            disaffirm the actions taken by the General Partner as its
            attorney-in-fact, or the Operator as the General Partner's
            substitute in that capacity, under this power in accordance with
            this Agreement.

            14.10.4. RELIANCE. Any Person other than a Partner may relay on the
            power of attorney granted in this Section without inquiry into this
            Agreement or compliance with it, regardless of whether the use of
            such power is in accordance with this Agreement; provided, that the
            General Partner or Operator shall be liable to the Partnership and
            severally to each Limited Partner for any grossly negligent or
            willful misuse of such power not in accordance with the other terms
            of this Agreement.

      14.11. PRINCIPLES OF CONSTRUCTION AND INTERPRETATION. In construing
this Agreement, the following principles shall be followed:

            (A) no consideration shall be given to the fact or presumption that
      one Party had a greater or lesser hand in drafting this Agreement:

            (B) examples shall not be construed to limit, expressly or by
      implication, the matter they illustrate:

            (C) the word "includes" and its syntactical variants mean "includes,
      but is not limited to" and corresponding syntactical variant expressions:
      and

            (D) the plural shall be deemed to include the singular and vice
      versa, as applicable.

      14.12. SETOFFS AND COUNTERCLAIMS. Except as otherwise provided herein,
each Party reserves to itself all rights, set-offs, counterclaims, and other
remedies and/or defenses which that Party is or may be entitled to arising
from or out of this Agreement or as otherwise provided by law.

                                        43
<Page>

      IN WITNESS WHEREOF, the Partners have executed this Agreement as of the
Effective Date.

                                        DOWNSTREAM ENERGY VENTURES CO.,
                                        L.L.C,

                                        By: /s/ William E. Puckett
                                           ------------------------------------
                                           William E. Puckett, Vice President

                                        WARREN PETROLEUM COMPANY,
                                        LIMITED PARTNERSHIP

                                        By: /s/ Stephen A. Furbacher
                                           ------------------------------------
                                            Stephen A. Furbacher, President

                                        AMOCO MB FRACTIONATION COMPANY

                                        By: /s/ A. Boyd Anderson
                                           ------------------------------------
                                            A. Boyd Anderson, President

                                       44
<Page>

                                   EXHIBIT A
                      TO LIMITED PARTNERSHIP AGREEMENT FOR
                         CEDAR BAYOU FRACTIONATORS, L.P.

                              ACCOUNTING PROCEDURE

                             I. GENERAL PROVISIONS

1.       As used in this Accounting Procedure, the following terms have the
         meaning set forth below:

         "Technical Employees" shall mean those employees of Operator having
         special and specific engineering or technical skills, including but not
         limited to process, project, design and environmental engineers, and
         whose primary function is the handling of specific operating conditions
         and problems.

         "Personal Expenses" shall mean Travel Expenses and other reasonable
         reimbursable expenses.

         "Travel Expenses" shall mean air fare, lodging, meals, laundry,
         business related telephone calls, taxis, car rental, tolls, parking and
         any other reasonable and necessary travel-related expenses.

         "Controllable Material" shall mean Material which at the time is so
         classified in the Material Classification Manual as most recently
         recommended by the Council of Petroleum Accountants Societies.

2.       CONFLICT WITH AGREEMENT

         In the event of a conflict between the provisions of this Accounting
         Procedure and the provisions of the Agreement to which this Accounting
         Procedure is attached, the provisions of the Agreement shall control.

3.       APPROVAL BY MANAGEMENT COMMITTEE

         When an approval or other agreement of the Parties is expressly
         required under this Accounting Procedure and if the Agreement to which
         this Accounting Procedure is attached contains no contrary provision in
         regard thereto, Operator shall notify and obtain the approval of the
         Management Committee.

                                       45
<Page>

                               II. DIRECT CHARGES

Operator shall charge the Account for the following items:

1.       LABOR

         A.  (1)  Salaries and wages of Operator's employees directly employed
                  at the Facility (even if such employees are also
                  contemporaneously employed at other facilities of Operator in
                  the Mont Belvieu area, including Operator's Warrengas Terminal
                  and Operator's Mont Belvieu Terminal) in the conduct of the
                  Operations.

             (2)  Salaries and wages of Operator's Technical Employees while
                  performing work related to a potential Capital Project
                  directly pertaining to the Facility, while working either in
                  Operator's Houston headquarters office or at the Facility,
                  subject to the limitations set forth in Article 3.2(f) of the
                  Agreement.

         B.  Operator's cost of holiday, vacation, sickness and disability
             benefits and other customary allowances paid to employees whose
             salaries and wages are chargeable to the Account under Paragraph
             1.A(1) of this Section II. Such costs under this Paragraph 1.B may
             be charged on a "when and as paid basis" or by "percentage
             assessment" on the amount of salaries and wages chargeable to
             the Account under Paragraph 1.A(1) of this Section II. If
             percentage assessment is used, the rate shall be based on the
             Operator's cost experience.

         C.  Expenditures or contributions made pursuant to assessments
             imposed by Governmental Authority which are applicable to
             Operator's costs chargeable to the Account under Paragraphs 1.A(1)
             and 1.B of this Section II.

         D.  Personal Expenses of those employees whose salaries and wages
             are chargeable to the Account under Paragraph 1.A(1) and 1.A(2)
             of this Section II.

         E.  Training for those employees whose salaries and wages are
             chargeable to the Account under Paragraph 1.A(1) of this
             Section II.

2.       EMPLOYEE BENEFITS

         Operator's actual costs of established plans for employees' group
         life insurance, hospitalization,

                                       46

<Page>

         pension, retirement, stock purchase, thrifts, bonus, and other
         benefit plans of a like nature, applicable to Operator's labor cost
         chargeable to the Account under Paragraph 1.A(1) of the this
         Section II.

3.       MATERIAL

         Materials purchased or furnished by Operator for the Facility as
         provided under Section IV of this Accounting Procedure.

4.       TRANSPORTATION

         Transportation of Material, but subject to the following limitations:

         A.      If Material is moved to the Facility from Operator's warehouse
                 or other properties, no charge shall be made to the Account
                 for a distance greater than the distance from the nearest
                 reliable supply store where like Material is normally
                 available, or railway receiving point nearest the facility,
                 unless agreed to by the Parties.

         B.      If surplus Material is moved to Operator's warehouse or other
                 storage point, no charge shall be made to the Account for a
                 distance greater than the distance to the nearest reliable
                 supply store where like Material is normally available, or
                 railway receiving point nearest the Facility, unless agreed to
                 by the Parties. No charge shall be made to the Account for
                 moving Material to other properties belonging to Operator,
                 unless agreed to by the Parties.

         C.      In the application of Paragraphs A and B above, the option to
                 equalize or charge actual trucking cost is available when the
                 actual charge is $400 or less excluding accessorial charges.
                 The $400 will be adjusted to the amount most recently
                 recommended by the Council of Petroleum Accountants Societies.

5.       CONTRACT SERVICES

         The cost of contract services of any kind, including those for
         technical services, consulting services, maintenance and equipment.

6.       EQUIPMENT FURNISHED BY OPERATOR

         A.      Operator shall charge the Account for use of Operator-owned
                 equipment, including, but not limited to, cars, trucks, cranes
                 or "cherry pickers", laboratory instruments, machine,
                 electrical and/or meter shop tools or instruments, and fire
                 fighting equipment

                                      47

<Page>

                 and training facilities, as may be used for the benefit of the
                 Facility from time to time, at rates commensurate with
                 Operator's actual costs of ownership and operation, not to
                 exceed the average commercial rates currently prevailing in
                 the immediate area of the Facility. Such rates may include
                 labor, maintenance, repairs, other operating expense,
                 insurance, taxes, depreciation and interest on gross investment
                 (less accumulated depreciation) not to exceed the prime rate
                 charged by Wells Fargo Bank, San Francisco per annum and an
                 element of the estimated cost to dismantle and abandon the
                 equipment.

         B.      In lieu of charges in Paragraph 6A above, Operator may elect
                 to use average commercial rates prevailing in the immediate
                 area of the Facility. For automotive equipment, Operator may
                 elect to use rates published by the Petroleum Motor Transport
                 Association.

7.       DAMAGES AND LOSSES TO FACILITY

         All costs or expenses necessary for the repair or replacement of all
         or any portion of the Facility made necessary because of damages or
         losses incurred by fire, flood, storm, theft, accident, or other
         causes. Operator shall furnish the Partnership with written notice
         of damages or losses incurred as soon as practicable after a report
         thereof has been received by Operator.

8.       LEGAL EXPENSES, SETTLEMENTS AND JUDGMENTS

         Expense of handling, investigating and settling Claims, discharging
         liens, payment of judgments, and amounts paid for settlement of
         Claims, including but not limited to amounts paid to third persons
         for personal injury, death or property damage, and fines levied by
         a Governmental Authority. No charge for services of Operator's legal
         staff or fees or expense of outside attorneys shall be made unless
         previously agreed to by the Partnership.

9.       TAXES

         All taxes of every kind and nature assessed or levied upon or in
         connection with the Facility which have been paid by the Operator
         for the benefit of the Partnership.

10.      INSURANCE

         Net premiums paid by Operator for insurance, as provided for in
         Article VI of the Agreement. In the event Operator acts as
         self-insurer for Workers' Compensation and Employers' Liability,
         Operator may include the risk under its self-insurance program in
         providing coverage under State and Federal laws and charge the
         Account at Operator's cost not to exceed manual rates.

                                       48

<Page>

         Operator shall also charge the Account for insurance deductibles.

11.      COMMUNICATIONS

         Costs of acquiring, leasing, installing, operating, repairing and
         maintaining communication systems including radio and microwave
         facilities serving the Facility. In the event communication facilities
         systems serving the Facility are Operator-owned, charges to the Account
         shall be made as provided in Paragraph 6 of this Article II.

12.      OFFICE SUPPLIES

         Cost of stationery and office supplies, and cleaning, repairing and
         maintaining office equipment located at the Facility.

13.      DATA PROCESSING

         Costs of data processing expenses, computer rental and other
         computer supplies used at the Facility.

14.      TRAVEL EXPENSES

         Travel Expenses of Operator's Houston-based headquarters personnel
         traveling to, from and working at the Facility.

15.      COMPLIANCE COSTS

         All direct costs and expenses related to compliance with Applicable
         Laws, including Environmental and Safety Laws, affecting the
         Facility including costs of pollution prevention, environmental
         permitting, environmental audits and surveys, and remediation
         programs.

16.      ABANDONMENT AND RECLAMATION

         Costs incurred for abandonment of the Facility, including
         dismantling, removal and restoration costs and costs required by
         Governmental Authority.

17.      PERMITS AND RIGHTS-OF-WAY

         Costs incurred in obtaining and maintaining permits, licenses,
         leases, rights-of-way and easements.

                                      49

<Page>

                     'Confidential Treatment Requested'

18.      AFFILIATE CHARGES

         Charges for any services or Materials provided by an Affiliate of
         Operator; provided, however, that such charges shall not exceed the
         average prevailing commercial rate for such services or Materials.

19.      UTILITIES

         Costs for electrical power, water, gas and any services provided by
         a utility company.

20.      OTHER EXPENDITURES

         Any other expenditure not covered or dealt with in the foregoing
         provision of this Section II and which is incurred by Operator and
         is of direct benefit to the Facility.

                                  III. OVERHEAD

As compensation for administrative services, supervision and warehousing
costs, Operator shall receive the Overhead Fees provided for in this Section
III (the "Overhead Fees"). Such Overhead Fees shall be in lieu of the office
expenses of Operator's headquarters office currently located in Houston,
Texas (but shall not be in lieu of the office expenses of Operator's field
offices) and salaries or wages plus applicable burdens and expenses of all
personnel of Operator, except those costs, expenses and salaries directly
chargeable under Section II.

1.       OPERATING OVERHEAD

         Operator, in addition to the actual costs and expenses provided in
         Section II, shall receive, as compensation for its administrative
         overhead expense in supervising the operation and maintenance of the
         Facility, which compensation shall begin upon the Effective Date, a
         sum equal to twelve percent (12%) of the costs and expense provided
         for in Section II of this Accounting Procedure, with the exception
         of fuel and electric power obtained from an outside source. The
*        maximum administrative overhead fee for 1998 shall be [REDACTED]. This
         sum shall be subject to adjustment on the first Day of each calendar
         year beginning in 1999, such adjustment to be computed by multiplying
         the rate currently in use by percentage increase or decrease in the
         average weekly earnings of Crude Petroleum and Gas Production Workers
         for the last calendar year compared to the preceding year as shown by
         "The Index of Average Weekly Earnings of Crude Petroleum and Gas
         Production Workers" as published by the United States Department of
         Labor, Bureau of Labor Statistics. Except for the employees whose
         salary, wages and expenses will be direct charges in accordance with
         Section II., Paragraph 1.A, the Overhead Fee,

                                      50

<Page>

                     'Confidential Treatment Requested'

         adjusted as aforesaid, shall be in lieu of all salaries and expenses
         of all personnel employed at all offices of Operator.

2.       OVERHEAD - CAPITAL PROJECTS

         To compensate Operator for overhead costs incurred in connection
         with a Capital Project, Operator at its sole discretion, shall
         either negotiate a rate prior to the beginning of such Project, or
         shall receive an Overhead Fee based on the following rates:

         A.       If the Operator absorbs its internal engineering, design and
                  drafting costs related to the project:

                  (1)      For Capital Projects actually costing less than
*                          [REDACTED] of the Capital Expenditures incurred;
*                 (2)      For Capital Projects actually costing [REDACTED] or
                           more, and where the Approved AFE is less than or
*                          equal to [REDACTED] plus [REDACTED] of that portion
*                          of the Approved AFE over [REDACTED]; and
*                 (3)      For Capital Projects actually costing [REDACTED] or
*                          more, and where the Approved AFE is over [REDACTED]
*                          plus [REDACTED] of that portion of the Approved AFE
*                          amount over [REDACTED].

         B.       If the Operator is reimbursed by the Partnership for internal
                  engineering, design and drafting costs related to the
                  project:

                  (1)      For Capital Projects actually costing less than
*                          [REDACTED] of the Capital Expenditures incurred;
*                 (2)      For Capital Projects actually costing [REDACTED] or
                           more, and where the Approved AFE is less than or
*                          equal to [REDACTED] plus [REDACTED] portion of the
*                          Approved AFE over [REDACTED]; and
*                 (3)      For Capital Projects actually costing [REDACTED] or
*                          more, and where the Approved AFE is over [REDACTED]
*                          plus [REDACTED] of that portion of the Approved AFE
*                          amount over [REDACTED].

         Total cost shall mean the gross costs of any one Capital Project.
         For the purpose of this paragraph, the component parts of a single
         Capital Project shall not be treated separately.

         On each Capital Project, Operator shall advise the Partnership in
         advance which of the above options shall apply.

         Expenditures subject to overhead will not be reduced by insurance
         recoveries, and no other

                                       51

<Page>

                       'Confidential Treatment Requested'

         overhead provisions of this Section III shall apply.

                   IV. PRICING OF ACCOUNT MATERIAL PURCHASES,
                           TRANSFERS AND DISPOSITIONS

         Operator is responsible for supplying Material and shall make proper
         and timely charges and credits for all Material movements. Operator
         shall make timely disposition of surplus Material, subject to the
         approval of the Management Committee as provided for in
         Article 2.3(q) of the Agreement, such disposal being made either
         through sale to Operator or sale to outsiders.

1.       PURCHASES

         Material purchased shall be charged to the Account at the price paid
         by Operator (including transportation) after deduction of all
         discounts received. In case of Material found to be defective or
         returned to vendor for any other reasons, credit shall be made to
         the Account when adjustment has been received by the Operator.

2.       TRANSFERS AND DISPOSITIONS

         Material furnished to the Facility from Operator's stock and
         Material transferred from the Facility or disposed of by the
         Operator, unless otherwise agreed to by the Parties, shall be priced
         on the following basis exclusive of cash discounts. Operator may
         also charge the Account with the cost of transporting such Material.

         A.       New Material (Condition A)

*                 New Material shall be priced at [REDACTED]

         B.       Good Used Material (Condition B)

                  Material in sound and serviceable condition and suitable for
                  reuse without reconditioning:

                  (1)      Material used on and moved from the Facility

*                          (a)      At [REDACTED], as determined by Paragraph A,
                                    if Material was originally charged to the
                                    Account as new

                                      52

<Page>

                    'Confidential Treatment Requested'

                                    Material or

*                          (b)      At [REDACTED], as determined by Paragraph A,
                                    if Material was originally charged to the
                                    Account as Condition B Material.

                  (2)      Material not used on and moved from the Facility

*                          (a)      At [REDACTED], as determined by Paragraph A.

                           (b)      The cost of reconditioning, if any, shall
                                    be absorbed by the property to which the
                                    Material is transferred.

         C.       Other Used Material

                  (1)      Condition C
                           Material which is not in sound and serviceable
                           condition and not suitable for its original function
                           until after reconditioning shall be priced at
*                          [REDACTED] as determined by Paragraph A. The cost of
                           reconditioning shall be charged to the Facility (if
                           the Material is being transferred to the Facility),
                           provided Condition C value plus cost of
                           reconditioning does not exceed Condition B value.

                  (2)      Condition D
                           Material, excluding junk, no longer for its original
                           purpose, but usable for some other purpose shall be
                           priced on a basis commensurate with its use. Operator
                           may dispose of Condition D Material under procedures
                           normally used by Operator without prior approval of
                           the Partnership.

                  (3)      Condition E
                           Junk shall be priced at prevailing prices. Operator
                           may dispose of Condition E Material under procedures
                           normally utilized by Operator without prior approval
                           of the Partnership.

         D.       Obsolete Material

                  Material which is serviceable and useable for its original
                  function but condition and/or value of such Material is not
                  equivalent to that which would justify a price as provided
                  above may be specially priced as agreed to by the Parties.
                  Such price should result in the Account being charged with
                  the value of the service rendered by such Material.

                                      53

<Page>

                     'Confidential Treatment Requested'

         E.       Pricing Conditions

                  (1)      Loading or unloading costs may be charged to the
*                          Account at the rate of [REDACTED] per hundred weight
                           on all tubular goods movements, in lieu of actual
                           loading or unloading costs sustained at the stocking
                           point. The above rate shall be adjusted as of the
                           first Day of each year following the Effective Date
                           by the same percentage increase or decrease used to
                           adjust the Overhead Fee cap in Section III. Each
                           year, the rated calculated shall be rounded to the
                           nearest cent and shall be the rate in effect until
                           the first Day of the next year. Such rate shall be
                           published each year by the Council of Petroleum
                           Accountants Societies.

                  (2)      Material involving erection costs shall be charged
                           at applicable percentage of the current knocked-down
                           price of new Material.

3.       PREMIUM PRICES

         Whenever Material is not readily obtainable at published or listed
         prices because of national emergencies, strikes or other unusual
         causes over which the Operator has no control, the Operator may
         charge the Account for the required Material at the Operator's
         actual cost incurred in providing such Material, in making it
         suitable for use, and in moving it to the Facility; provided notice
         in writing is furnished to the Partnership of the proposed charge
         prior to charging the Account for such Material.

4.       WARRANTY OF MATERIAL FURNISHED BY OPERATOR

         Operator does not warrant the Material furnished. In case of
         defective Material, credit shall not be passed to the Account until
         adjustment has been received by Operator from the manufacturers or
         their agents.

                                 V. INVENTORIES

The Operator shall maintain detailed records of Controllable Material.

1.       PERIODIC INVENTORIES, NOTICE AND REPRESENTATION

         At reasonable intervals, inventories shall be taken by Operator of
         the Account Controllable Material. Written notice of intention to
         take inventory shall be given by Operator to the Management
         Committee at least thirty (30) days before any inventory is to begin
         so that

                                       54

<Page>

         the Management Committee may be represented when any inventory is
         taken. Failure of the Management Committee to be represented at an
         inventory shall bind the Management Committee to accept the
         inventory taken by Operator.

2.       RECONCILIATION AND ADJUSTMENT OF INVENTORIES

         Adjustments to the Account resulting from the reconciliation of a
         physical inventory shall be made within six months following the
         taking of the inventory. Inventory adjustments shall be made by
         Operator to the Account for overages and shortages, but, Operator
         shall be held accountable only for shortages due to lack of
         reasonable diligence.

3.       SPECIAL INVENTORIES

         Special inventories may be taken whenever there is any sale, change
         of interest, or change of Operator. It shall be the duty of the
         Party selling to notify the other Party as quickly as possible after
         the transfer of interest takes place. In such cases, both the seller
         and the purchaser shall be governed by such inventory. In cases
         involving a change of Operator, all Parties shall be governed by
         such inventory.

4.       EXPENSE OF CONDUCTING INVENTORIES

         A.       The expense of conducting periodic inventories shall be
                  charged to the Account.

         B.       The expense of conducting special inventories shall be
                  charged to the Party requesting such inventories, except
                  inventories required due to change of Operator shall be
                  charged to the Account.

                                               55

<Page>

                                    EXHIBIT B

                      TO THE LIMITED PARTNERSHIP AGREEMENT
                                       OF
                         CEDAR BAYOU FRACTIONATORS, L.P.

                               INCOME TAX MATTERS

         1. TAX RETURNS, PROCEEDINGS AND ELECTIONS. Tax returns, proceedings,
and elections shall be governed by the provisions of this Exhibit B as it may
be amended from time to time by a vote of the Management Committee.

                  (a) Downstream Energy Ventures, L.L.C., the Managing
General Partner, is designated the tax matters partner ("TMP") as defined in
Section 6231(a)(7) of the Code. The designation of TMP shall be effective
only for operations conducted by the Partners pursuant to this Agreement.

                  (b) The TMP shall cause to be prepared all necessary
federal, state, and local partnership income, excise, and property tax
returns and furnish a copy of the proposed federal and state income tax
returns to the Partners for their review not later than one month prior to
the due date, including extensions, for filing such returns. The TMP shall
timely file such returns and, upon the written request of a Partner, shall
provide the Partners with schedules which are consistent with the treatment
of all items on those returns. The TMP agrees to use reasonable efforts in
the preparation and filing of such tax returns but, in doing so, shall incur
no liability to any Partner with respect to such returns or any elections
relating thereto. In addition, the TMP shall furnish, within sixty (60) Days
of the close of each calendar year, estimates of the tax information required
by the Partners for federal and state income tax reporting requirements.

                  (c) The Partner(s) shall furnish the TMP with such information
as it may reasonably request to aid in the preparation of the applicable returns
and which will permit it to provide the Internal Revenue Service with sufficient
information so that proper notice can be mailed-to such Partner(s) as provided
in Section 6223 of the Code.

                  (d) To the extent and in the manner provided by applicable
treasury regulations, the TMP shall keep each Partner and Management
Committee representative informed of all administrative and judicial
proceedings for the adjustment of Partnership items (as defined in Section
6231(a)(3) of the Code) at the Partnership level.

                  (e) If an administrative proceeding contemplated under Section
6223 of the Code has begun, the Partner(s) shall notify the TMP of their
treatment of any Item on their federal income tax return in a manner which is or
may be inconsistent with the treatment of that item on the

                                       56
<Page>

Partnership's return.

                  (f) The TMP shall not enter into any extension of the period
of limitations as provided under Section 6229 of the Code without the prior
written consent of the Partner(s) and each Management Committee member.

                  (g) Any Partner who enters into a settlement agreement with
the Secretary of the Treasury with respect to Partnership Items shall promptly
notify the other Partner(s), if any, and each Management Committee member of
such settlement agreement.

                  (h) The TMP shall not bind other Partner(s) to a settlement
agreement without obtaining the written concurrence of the Partner(s) who
will be bound by such agreement.

                  (i) The TMP shall notify all Partner(s) and each Management
Committee member of any intention to file a petition with a court for a
readjustment of any Partnership Items. Such notice shall be given within a
reasonable time so that the Partner(s) and each Management Committee member
may participate in choosing the forum for the filing of any petition. This
provision shall not apply to any Partner who does not have an interest in the
outcome of such matter. Whether a Partner has an interest in the outcome will
be determined using the standard in Section 6226(d) of the Code. Further, the
TMP or Partner who brought the action under Section 6226 of the Code, shall
provide the other Partners and each Management Committee member with notice
of any intention to seek review of a determination by any court under that
Section.

                  (j) No Partner may file a request for an administrative
adjustment of Partnership Items for any taxable year pursuant to Section 6227
of the Code without first notifying all other Partners and each Management
Committee member. If the other Partner(s) agree with the requested
adjustment, the TMP shall file the request for administrative adjustment on
behalf of the Partnership.

                  (k) If any part of an administrative adjustment request filed
by a Partner is not allowed by the Internal Revenue Service, the Partner filing
such request shall seek the concurrence of other Partner(s) and each Management
Committee member with regard to the filing of a petition with a court and with
regard to seeking review of the determination by any court in the same manner as
provided in Section 1 (i) of this Exhibit.

                  (l) The TMP and the Partners shall use all reasonable efforts
to comply with the responsibilities as outlined herein and in Sections 6222
through 6233 of the Code, but shall incur no liability to any Partner for
failure to fulfill such responsibilities.

                  (m) The provisions of this Exhibit B shall survive the
termination of the Partnership or the termination of any Partner's interest in
the Partnership and shall remain binding on the Partner(s) for a period of time
necessary to resolve with the Internal Revenue Service or the

                                       57
<Page>

Department of the Treasury any and all matters regarding the federal income
taxation of the Partnership and any applicable state income tax matters.

         2. ELECTIONS. The Parties agree that the TMP is directed to make the
following elections on behalf of the Partnership in the appropriate returns
of the Partnership prepared pursuant to Section 1 above:

                  (a) To adopt the accrual method of accounting;

                  (b) To compute the allowance for depreciation or cost recovery
using the shortest permissible life and most rapid recovery method permitted
under the Code;

                  (c) To elect the calendar year as the fiscal year of the
Partnership;

                  (d) To elect in a timely manner pursuant to Section 266 of
the Code and the Treasury Regulations thereunder to charge to the capital
account with respect to the property acquired or constructed by the
Partner(s) under this Agreement all taxes and carrying charges including
interest on indebtedness, which may be capitalized thereunder;

                  (e) To elect to amortize all organization costs of the
Partnership under Section 709 of the Code; and

                  (f) To make such other elections as the Management Committee
may direct.

         3. SECTION 754 ELECTION. Upon the transfer of an interest in the
Partnership and upon the written request of the transferee, the Partnership
shall make an election at the written request of the transferee Partner
pursuant to Section 754 of the Code to adjust the basis of Partnership
Property. Any Partner or successor in interest, whose basis in Partnership
Property is adjusted pursuant to Section 743(b) of the Code, shall assume
sole compliance responsibility to reflect the adjustment to basis of its
Partnership Property under Section 743(b) of the Code, to prepare and attach
a statement to its income tax return showing the computation of the
adjustment and the Partnership properties to which the adjustment has been
allocated.

                                       58
<Page>

                               EXHIBIT C - PART I

                               SURFACE LEASE AREA

The Surface Lease Area is that area within the "Surface Lease Boundary" as
indicated on Warren Drawing Number CBF-1001, "Fractionator Shared Services &
Property Boundaries Plot Plan" (the "Plot Plan"), as copy of which is
attached hereto and incorporated herein; and as more fully described in full
in the metes and bounds description attached hereto and certified by Robert
L. Hall, Registered Professional Land Surveyor No. 1610, dated December 12,
1997, which is incorporated herein by reference.

<Page>

STATE OF TEXAS)
COUNTY OF CHAMBERS)

FIELD NOTES of a 53.880 acre tract of land situated in the William Bloodgood
League, Abstract Number 4, Chambers County, the Henry Griffith League,
Abstract Number 12, Chambers County, the William Bloodgood Augmentation
Survey, Abstract Number 5, Chambers County, and being out of and a part of a
242.5057 acre tract of land called Tract 9 and conveyed to Midstream
Combination Corp. by Chevron U.S.A. Inc., in deed dated August 20, 1996, and
recorded in volume 308 at Page 85 of the Official Public Records of Chambers
County. This 53.880 acre tract of land is more particularly described by
metes and bounds as follows, to-wit:

NOTE: ALL BEARINGS ARE LAMBERT GRID BEARINGS AND ALL COORDINATES REFER TO THE
STATE PLANE COORDINATE SYSTEM, SOUTH CENTRAL ZONE, AS DEFINED BY ARTICLE 21.071
OF THE NATURAL RESOURCES CODE OF THE STATE OF TEXAS, 1927 DATUM. ALL DISTANCES
ARE ACTUAL DISTANCES. REFERENCE IS MADE TO PLAT OF EVEN DATE ACCOMPANYING THIS
METES AND BOUNDS DESCRIPTION.

BEGINNING at a brass cap set in concrete for the Northeast corner of this
tract of land, having a State Plane Coordinate Value of Y = 752,799.30 and X
= 3,299,929.27. From this BEGINNING corner a 1 1/4 inch iron pipe found for
the Northeast corner of said Bloodgood League, an interior corner of the
Henry Griffith League, Abstract Number 12, Chambers County, an angle point in
the North line of said 242.5057 acres, and an angle point in the South line
of a tract of land conveyed to Texas Eastern Transmission Corporation by 0.
Z. Smith, et ux, in deed dated January 3, 1959, and recorded in Volume 227 at
Page 201 of the Deed Records of Chambers County bears North 15 DEG. 06' 33"
West a distance of 1245.27 feet.

THENCE in a Southerly direction with the East line of this tract of land the
following courses to brass caps set in concrete:

         South  15 DEG. 19' 31" East  495.89 feet;
         North  79 DEG. 11' 30" East   39.03 feet;
         South  13 DEG. 05' 10" East   72.16 feet;
         South  74 DEG. 48' 00" West   36.40 feet;
         South  15 DEG. 20' 53" East 1099.45 feet to a brass cap set in
concrete for the Southeast corner of this tract of land.

THENCE South 76 DEG. 53' 10" West with the South line of this tract of land a
distance of 1149.43 feet to a brass cap set in concrete for the Southwest corner
of this tract of land, in the West line of said 242.5057 acres, and in the East
line of a 25.28 acre tract of land called First Tract and conveyed to Exxon
Pipeline Corporation in Partition Deed dated July 22, 1971, and recorded in
Volume 326 at Page 646 of the Deed Records of Chambers County.

<Page>

PAGE NO. 2 - 53.880 ACRES

THENCE North 11 DEG. 44' 58" West with the West line of this tract of land,
the West line of said 242.5057 acres, and the East line of said 25.28 acres a
distance of 626.28 feet to a brass cap set in concrete for an interior corner
of this tract of land, an interior corner of said 242.5057 acres, and the
Northeast corner of said 25.28 acres.

THENCE SOUTH 76 DEG. 49' 25" West with the a South line of this tract of
land, a South line of said 242.5057 acres, and the North line of said 25.28
acres a distance of 152.77 feet to a brass cap set in concrete for the most
Northerly Southwest corner of this tract of land.

THENCE in a Westerly and Northerly direction with the West line of this tract
of land the following courses to brass caps set in concrete:

         North  19 DEG. 42' 27" East   81.08 feet;
         North  13 DEG. 03' 18" West  228.62 feet;
         South  76 DEG. 56' 42" West  278.41 feet;
         South  13 DEG. 03' 18" East   77.07 feet;
         South  76 DEG. 56' 42" West  133.07 feet;
         North  13 DEG. 03' 18" West  314.52 feet;
         South  76 DEG. 56' 42" West  171.52 feet;
         North  13 DEG. 03' 18" West  350.11 feet to a brass cap set in
concrete for the Northwest corner of this tract of land, in a non-tangent curve
to the right.

THENCE in a Northeasterly direction with the North line of this tract of land
and said non-tangent curve to the right, concave Southeast, having a central
angle of 180 DEG. 331' 33", a radius of 1185.34 feet, an arc length of 383.95
feet, and a chord bearing and distance of North 53 DEG. 10' 11" East 382.28
feet to a brass cap set in concrete for a corner of this tract of land and
the end of said curve.

THENCE in an Easterly direction with the North line of this tract of land the
following courses to brass caps set in concrete:

         North  72 DEG. 12' 42" East  106.35 feet;
         North  74 DEG. 27' 33" East   93.65 feet;
         North  77 DEG. 15' 59" East 1211.38 feet to the PLACE OF BEGINNING,
containing within said boundaries 53.880 acres of land.

SURVEYED: December 8, 1997.

<Page>

PAGE NO. 2 - 53.880 ACRES

                             SURVEYOR'S CERTIFICATE

I, Robert L. Hall, Jr., Reg Professional Land Surveyor No. 1610, do hereby
certify that the foregoing field notes were prepared from an actual survey made
on the ground on the date shown and that all lines, boundaries and landmarks are
accurately described therein.

WITNESS my hand and seal at Baytown, Texas, this the 12th., day of December,
A.D., 1997.

/s/ Robert L. Hall, Jr.

REG. PROFESSIONAL LAND SURVEYOR
NO. 1610
97-1388H. FDN

[SEAL]

<Page>

                               EXHIBIT C - PART II

                                  FRACTIONATOR

The Fractionator includes vessels and equipment for raw product treating,
fractionation and natural gasoline treating as shown and described on the
drawing attached hereto "Fractionator Plant - Vessel, Equipment & Building
Legend" (labeled "CADD File: CBF-1002) attached hereto and incorporated
herein; including, without limitation, the following:

Raw product treating for the inlet stream into the Facility consists of three
contactors (presently utilizing monoethanol amine), two caustic contactors
utilizing the UOP extractive Merox process and the associated equipment to
circulate, regenerate and operate these systems.

Fractionation towers designated T-1 through T-12 consist of two deethanizers
(T-1, T-5), three depropanizers ( T-2, T-7, T-9 ), two debutanizers ( T-4A,
T-10) and three deisobutanizers ( T-6, T-8, T-12). Towers T-3 and T-11 are
not in use at the present time and T-4 is utilized as a feed drum.

Natural gasoline treating provides a "Doctor" sweet product.

Injection pumps transfer all finished products to the underground storage
terminal with metering of all finished products (metering to be completed).

Utilities to support fractionation include cooling towers #1, #2, #3, #4 and
#6, steam boilers #1, #2, #3, #4, #8, plant air/instrument air, hot oil
furnace A and hot oil furnace B which provide heat to reboil towers T-8, T-9,
T-10, aerial coolers, propane refrigeration systems for the deethanizers, and
various buildings including a central control room with all controls for the
fractionation process, offices, storage buildings and their contents.

<Page>

                              EXHIBIT C - PART III
                               RELATED FACILITIES

The Related Facilities are the following assets, which are further reflected
on and marked as the "Off Site Fractionator Assets" on Warren Drawing Number
CBF-1001, "Fractionator Shared Services & Property Boundaries Plot Plan" (the
"Plot Plan"), as copy of which is attached hereto and incorporated herein:

o     three water wells located west and southwest of the Facility including the
      pumps and piping to transport the water to the Facility
o     the fire water pumps located north northwest of the Facility at the fresh
      water canal
o     the flare tank pump out line
o     the "Outfall" which is used for the NPDES permit for the Facility located
      west of the Facility on the drainage canal, as marked on the Plot Plan
o     the piping to bring nitrogen into the Facility from the Air Liquide meter
      station located west of the Facility
o     the electrical power line bringing electricity from the H L & P substation
      to number 6 cooling tower which is located on the east and north side of
      the Facility
o     the imports to manifold area LPG pipelines located on the east side of the
      Facility
o     the finished product metering to be located east of the Facility
o     the potable water lines for Mont Belvieu City water
o     the sewer lines to the City of Mont Belvieu
o     the telephone and LAN fiber optics lines
o     the telephone system
o     the entire fire water system including all piping inside and adjacent to
      the Facility.

These assets are depicted on the Plot Plan thereon.

<Page>

                              EXHIBIT C - PART IV

                                    PERMITS

<Table>
<Caption>
----------------------------------------------------------------------------------------------------
        PERMIT           AGENCY         PERMIT REQUIREMENTS AND                DATE OF ISSUE/
                                          SPECIAL CONDITIONS                  EXPIRATION DATE
----------------------------------------------------------------------------------------------------
<S>                      <C>       <C>                                     <C>
     TXD980625974          EPA     Hazardous Waste Notification I.D.
----------------------------------------------------------------------------------------------------
       TX0002887           EPA     NPDES Permit                            Issued: Sept. 28, 1988
----------------------------------------------------------------------------------------------------
        GLP-001            TRRC    Texas Water Dishcharge Permit.          Issued: Oct. 20, 1987
                                                                           Expires: March 1, 2001
----------------------------------------------------------------------------------------------------
        P009174            TRRC    Gas Plant Evaporation/Retention Pit     Issued July 29, 1988
                                   (Amine sump)                            No Experiation
----------------------------------------------------------------------------------------------------
        P009175            TRRC    Gas Plant Evaporation/Retention Pit     Issued July 29, 1988
                                   (158 A Classifier sump)                 No Expiration
----------------------------------------------------------------------------------------------------
        P009176            TRRC    Gas Plant Evaporation/Retention Pit     Issued July 29, 1988
                                   (158 Classifier sump)                   No Expiration
----------------------------------------------------------------------------------------------------
        P009177            TRRC    Gas Plant Evaporation / Retention Pit   Issued July 29, 1988
                                   (Truck dock sump)                       No Expiration
----------------------------------------------------------------------------------------------------
        Pending            TRRC    Gas Plant Evaporation / Retention Pit   Pending Approval -
                                   (Truck dock sump)                       Applied for lst. Quarter
                                                                           1997
----------------------------------------------------------------------------------------------------
         5452             TNRCC    Texas Air Operating Permit (New Source  Issued: August 30, 1993
                                   Review Permit)                          Expires: August 30, 2003
----------------------------------------------------------------------------------------------------
        O-00612           TNRCC    Texas Federal Operating Permit          Pending Approval -
                                   Application Account Number - CI-0022-A  Application submitted -
                                                                           4th Quarter 1997
----------------------------------------------------------------------------------------------------
</Table>

<Page>

                                    EXHIBIT C
                                     PART V
                                    CONTRACTS

<Table>
<Caption>
WARREN                                                                                  CONTRACT
FILE NO.       CONTRACT PARTY                           TYPE OF CONTRACT                  DATE
--------       --------------                           ----------------                --------
<S>            <C>                                      <C>                             <C>
10003          Basis Petroleum                          Fractionation                   02/25/97

10004          Arco Oil & Gas Company                   Fractionation                   02/24/93

10007          Amerada Hess Corporation                 Fractionation                   01/08/96

10035          Valero Marketing, L.P.                   Fractionation                   10/19/95

10039          Unocal Corporation                       Fractionation                   04/15/96

10043          Marathon Oil Company                     Fractionation                   07/05/94

10044          Marathon Oil Company                     Fractionation                   12/01/92

10067          Mobil Oil Corporation                    Fractionation                   04/01/97

10076          Conoco Inc.                              Fractionation                   07/01/97

10078          Amerada Hess Corporation                 Fractionation                   09/28/93

10080          El Paso Field Services Co.               Fractionation                   08/01/97

10082          Mapco Natural Gas Liquids Inc.           Fractionation                   05/15/97

97-11-00468    Natural Gas Clearinghouse                Gas Sales                       01/01/98

(None)         The Light Company                        Electrical Supply               09/27/96

(None)         David Baker Manley                                                       10/16/95

(None)         Pritchard                                                                1995
</Table>

<Page>

                               EXHIBIT C - PART VI
                       SURFACE LEASE AREA EXCLUDED ASSETS

The Surface Lease Area Excluded Assets are the following assets, which are
further reflected on and marked as "Excluded & Retained by Warren" on Warren
Drawing Number CBF-1001, "Fractionator Shared Services & Property Boundaries
Plot Plan" (the "Plot Plan") attached hereto and incorporated herein:

o     the butane isomerization Facility (labeled "ISONM')
o     the 10 inch pipeline dedicated to delivering feed to the butane
      isomerization Facility
o     the nitrogen line delivering nitrogen to the terminal
o     the natural gas line delivering fuel gas to the terminal
o     the electrical feeder line from the H L & P substation delivering
      electricity to the butane isomerization Facility
o     the flare line from the terminal
o     the Chevron Pipeline (CPL) propane line
o     the butane isomerization Facility flare, flare line and flare knock out
      tank
o     the hydrogen metering station and piping to the butane isomerization
      Facility
o     the pipelines for instrument air, hydrogen, fuel gas, nitrogen, steam and
      RO water, brine water, hot oil fill from storage, the Cedar Bayou fuel gas
      line and the fiber optics line all associated with the butane
      isomerization Facility
o     the phone, DCS, and LAN lines in the butane isomerization Facility
o     the potable water line to the butane isomerization Facility
o     the Chevron Pipeline corridor running east and west through the Facility

<Page>

                                    EXHIBIT D

                                       TO

                        LIMITED PARTNERSHIP AGREEMENT

                                 LEASE AGREEMENT

                  WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP

                                      AND.

                         CEDAR BAYOU FRACTIONATORS, L.P.

<Page>

                                TABLE OF CONTENTS
<Table>
<S>                                                                                       <C>
1.      RENTAL ............................................................................1
2.      TERM ..............................................................................1
3.      OPERATIONS AND MAINTENANCE ........................................................1
4.      LIABILITY .........................................................................2
5.      REMEDY FOR BREACH .................................................................2
6.      CONSTRUCTION BY LESSEE ............................................................3
7.      ENCUMBRANCE OF LEASEHOLD ESTATE ...................................................4
8.      WARANTIES AND LIMITATIONS AND DISCLAIMERS .........................................4
9.      MECHANICS' LIENS ..................................................................5
10.     CONDEMNATION ......................................................................5
11.     NOTICES ...........................................................................6
12.     FORCE MAJEURE......................................................................7
13.     ALTERNATIVE DISPUTE RESOLUTION ....................................................8
14.     RESTRICTION ON ASSIGNMENT ........................................................12
15.     NO COMMISSIONS, FEES OR REBATES  .................................................12
16.     SEVERABILITY .....................................................................12
17.     GOVERNING LAW ....................................................................13
18.     ENTIRE AGREEMENT, AMENDMENT AND WAIVER ...........................................13
19.     SETOFFS AND COUNTERCLAIMS ........................................................13
20.     NO PARTNERSHIP, ASSOCIATION, ETC. ................................................13
21.     EXHIBITS .........................................................................13
22.     DTPA WAIVER.......................................................................13
23.     PRINCIPLES OF CONSTRUCTION AND INTERPRETATION.....................................14
24.     FURTHER DOCUMENTS.................................................................14
25.     HEADINGS AND PARAGRAPHS...........................................................14
26.     NO THIRD PARTY BENEFICIARY........................................................14
27.     RIGHT OF FIRST REFUSAL............................................................14
</Table>

                                       i
<Page>

EXHIBITS

         Exhibit A ..........................The Property

                                       ii
<Page>

                      'Confidential Treatment Requested'

                                 LEASE AGREEMENT

            In consideration for the mutual covenants herein, effective
  January 1, 1998, WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP ("Lessor")
  does hereby lease, let and demise the property described on Exhibit A
  attached hereto (the "Property") to CEDAR BAYOU FRACTIONATORS, L.P.
  ("Lessee") for the purposes of owning, operating, modifying and constructing
  modifications to, repairing and maintaining a natural gas liquids
  fractionation facility in accordance with the following terms and
  conditions. Lessor and Lessee are sometimes referred to herein as "Party"
  or, collectively, "Parties."

      1. RENTAL. This agreement (the "Lease") is given in consideration of
* [REDACTED] paid by Lessee to Lessor, receipt of which is hereby acknowledged,
  said amount shall cover the rental hereunder for the period of January 1,
  1998 to December 31, 2022. In addition, Lessee shall reimburse Lessor for
  all property taxes, ad valorem taxes and similar obligations (property
  taxes) assessed during the term hereof with respect to the Property and all
  improvements thereon owned by the Lessee which are paid by Lessor, within
  thirty (30) days of Lessee's receipt of Lessor's invoice itemizing such
  taxes, subject to Lessee's right to contest, in good faith, any such
  assessment or revaluation made by the governmental authority assessing such
  tax. If Lessee elects to contest any such assessment, then Lessee shall
  indemnify and hold harmless Lessor for all fines, penalties, interest,
  liens and other claims which may arise as the result of any delay in making
  payments or Lessee's challenge of the assessments, as well as for any
  increase in taxes to Lessor on its adjoining property should the challenge
  proceeding result in a reassessment of same. All payments due Lessor
  hereunder shall be remitted by Lessee to Lessor either in the form of a
  check at the address identified in Paragraph 11 or by wire transfer or
  other electronic means in accordance with the wire transfer or electronic
  payment instructions provided by Lessor in writing from time to time.

      2. TERM. This Lease shall be commence and be effective as of January 1,
  1998 (the "Effective Date"), and shall continue until December 31, 2022,
  (the "Primary Term") and year to year thereafter (each said year being and
  "Extended Term") unless and until either Party terminates this Agreement as
  of the end of either the Primary Term or any successive Extended Term by
  giving written notice to the other Party at least nine (9) months prior to
  such termination date. The Primary Term and the Extended Terms, if any, will
  be collectively referred to as the "Term" of this Lease. If Lessee exercises
* its option to extend the Lease, rental in the amount of [REDACTED] for each
  Extended Term shall be paid on or before the expiration of the Primary Term
  or the prior Extended Term, as applicable. Any notice or payment due under
  this Paragraph shall be sent to Lessor at the address in Paragraph 11.

      3. OPERATIONS AND MAINTENANCE. (a) Lessee shall maintain the Property
  in accordance with the requirements, standards and procedures of all
  applicable local, state and federal laws governing safety, toxic, hazardous
  or deleterious substances and environmental protection, and regulations
  promulgated thereunder. Lessee shall use the Property for the purposes of
  operating, repairing, modifying and constructing modifications to, and
  maintaining a natural gas liquids

                                       1
<Page>

fractionation facility, and associated gas and liquids pipelines and
appurtenant surface equipment, or any combination thereof. Should Lessee make
any use of the Property other than those uses described, it shall not be
considered to be in breach hereunder unless and until written notice and
demand for cessation of such use has been delivered by Lessor to Lessee
pursuant to Paragraph 5 below and Lessee shall have the time allowed for in
said Paragraph 5 to cease such use or otherwise cure such default.

      (b) Lessee assumes all responsibility for and agrees to bear and pay
all costs and expenses and other obligations associated with the maintenance
and use of the Property on and after the Effective Date. Lessee shall be
entitled to remove any and all improvements and fixtures affixed to the
Property and any personal property for a period of one (1) year from and
after the date of termination, but shall be obligated only to remove personal
property. Thereafter, any such improvements and fixtures still remaining
shall become part of the Property and shall be owned by Lessor and title to
any remaining personal property shall pass to Lessor and Lessor shall be
entitled to dispose of same in any manner without making an accounting
thereof to Lessee.

      (c) Lessee shall have the rights of ingress and egress across Lessor's
surrounding and/or adjacent properties by use of existing roadways. Lessee
shall limit said access to routes approved in advance by Lessor and shall
create no thorough-fares or roadways without the express written consent of
Lessor. Lessor shall have the rights of ingress and egress across the Lease
premises for the operation of equipment and facilities contained thereon
and/or surrounding properties. Lessee and Lessor shall share in the
maintenance of all jointly used roadways proportionate to each Parties'
respective use thereof.

      (d) Lessee retains the right to grant new and/or additional rights of
way, easements or any other surface use rights to any third parties provided
such grants do not materially interfere with Lessee's quiet use and enjoyment
of the Property.

      4. LIABILITY. Lessee shall protect, indemnify and hold harmless Lessor,
its officers, agents, employees and Affiliates against all claims by third
parties for damage to property, personal injury (including death), fines,
penalties and any other losses (including reasonable and actual attorney's
fees and costs of litigation) arising out of or in any way connected with
Lessee's use, maintenance and operation of the Property during the term of
this Lease, excluding only those matters arising out of Lessor's occupation
or use of, or presence on, the Property; provided, however, that nothing in
this Lease, including any indemnities given herein, shall be construed so as
to lessen or modify in any way any of Lessee's or its constituent partners'
indemnity rights and limitations of liability granted by Lessor, with regard
to Lessor's prior ownership and operation of the facilities located on the
Property and the Excluded Assets as same are provided for that certain
Limited Partnership Agreement for Cedar Bayou Fractionators, L.P. with an
effective date of January 1, 1998.

      5. REMEDY FOR BREACH. In the event that Lessor considers that Lessee
has at any time (i) violated any of its obligations under this Lease, (ii)
failed to make any payment within thirty (30) days of Lessor's written
demand, (iii) terminated its operations; (iv) otherwise liquidated or
dissolved

                                        2
<Page>

itself upon the filing of a bankruptcy, receivership, or respite petition by
or against Lessee, and the failure to dismiss same within sixty (60) days, or
(v) upon Lessee's suspension, failure or insolvency, Lessor shall notify
Lessee in writing setting out the specific facts upon which such claim is
based. Upon receipt of such notice, Lessee shall have thirty (30) days to
cure any breach or other deficiency. If an obligation of which Lessee is
considered by Lessor to be in default is one other than payment of monies and
is not reasonably capable of being performed within said thirty (30) days,
Lessee shall be obligated to commence within that thirty (30) days such
actions as are necessary to cure the default and to continue such actions
with reasonable diligence until that performance is completed. Should Lessee
fail to commence the cure of the alleged breach or deficiency within the time
allowed, Lessor, without putting Lessee in default may, at its option, cancel
this Lease. Any such termination shall be an additional remedy and shall not
prejudice the right of Lessor to collect any amounts due it hereunder for any
damage or loss suffered by it and shall not waive any other remedy to which
Lessor may be entitled for breach of this Lease.

      6. CONSTRUCTION BY LESSEE

            (a) GENERAL CONDITIONS. Lessee may, at any time and from time to
time during the term of this Lease, erect, maintain, alter, remodel,
reconstruct, rebuild, replace, and remove buildings and other improvements on
the Property, and correct and change the contour of the Property, subject to the
following:

            (i)   Lessee bears the cost of any such work; and

            (ii)  The Property must at all times be kept free of mechanics' and
                  materialmen's liens.

            (b)   EASEMENTS AND DEDICATIONS. Lessor must cooperate with Lessee
concerning easements and dedications of the Property as follows:

            (i)   Granting. To provide for the more orderly development of the
                  Property, it may be necessary, desirable, or required that
                  pipeline, drainage, gas supply, power lines, public use, and
                  other easements and dedications and similar rights be granted
                  or dedicated over or within portions of the Property. Lessor
                  must, on Lessee's request, join with Lessee in executing and
                  delivering the documents, from time to time, and throughout
                  the Lease term, as may be appropriate, necessary, or required
                  by applicable governmental agencies, public utilities, and
                  private entities for the purpose of granting such easements
                  and dedications; provided, however, Lessor may not be
                  compelled to do so with regard to any easements, dedications
                  or similar rights which, when exercised by the grantee of
                  same, would result in construction of facilities or activities
                  by third parties which materially interfere with Lessor's
                  operations on the adjacent properties.

                                       3
<Page>

            (ii)  Expenses. Lessee exclusively bears the cost and expense of any
                  action required of Lessor under Subparagraph (i) above.

      7.    ENCUMBRANCE OF LEASEHOLD ESTATE.

            (a) LESSEE'S RIGHT TO ENCUMBER. Lessee may, at any time and from
time to time, encumber the leasehold interest, by deed of trust, mortgage, or
other security instrument, without obtaining Lessor's consent, but no such
encumbrance shall constitute a lien on Lessor's fee title to the Property. The
indebtedness secured by the encumbrance will at all times be and remain
inferior and subordinate to all the conditions, covenants, and obligations of
this Lease and to all of Lessor's rights under this Lease. References in this
Lease to "Lender" refer to any person or entity to whom Lessee has encumbered
its leasehold interest.

            (b) NOTICES TO LENDER. At any time after execution and
recordation in Chambers County, Texas, of any mortgage or deed of trust
encumbering Lessee's leasehold interest, Lender must notify Lessor in writing
that the mortgage or deed of trust has been given and executed by Lessee and
furnish Lessor with the address to which it wants copies of notices to be
mailed, or designate some person or corporation as its agent and
representative for the purpose of receiving copies of notices. Lessor must
mail to Lender and to any agent or representative designated by Lender, at
the addresses given, duplicate copies of all written notices that Lessor
gives or serves on Lessee under the terms of this Lease after receiving such
a notice from Lender.

            (c) LENDER'S CONSENT REQUIRED FOR MODIFICATION. At any time after a
notice has been delivered to Lessor pursuant to Subparagraph (b) above, Lessor
and Lessee will neither modify nor terminate this Lease by mutual consent
without Lender's written consent.

            (d) LENDER'S RIGHT TO PREVENT FORFEITURE. Lender may do any act
required of Lessee to prevent forfeiture of Lessee's leasehold interest; all
such acts are as effective to prevent a forfeiture of Lessee's rights under this
Lease as if done by Lessee.

      8.    WARRANTIES AND LIMITATIONS AND DISCLAIMERS.

            (a) WARRANTIES. Lessor warrants that (i) Lessor has authority to
enter into this Lease and (ii) Lessee may peaceably enjoy the use of the
Property free of claims by any other Party claiming by, through or under
Lessor. Lessor hereby warrants and agrees to defend title to the Property
against the claims of all persons claiming by through or under Lessor, but
not otherwise. Lessor covenants that the Property is not subject to any liens,
claims or other encumbrances other than rights of way and easements of record
as of the date hereof and that it has no knowledge nor has it received any
notice that it is in default under the terms thereof.

            (b) LIMITATIONS AND DISCLAIMERS. EXCEPT AS SET FORTH IN THIS
PARAGRAPH, LESSOR MAKES NO WARRANTY OF ANY OTHER KIND WHATEVER, EXPRESS OR
IMPLIED, WITH RESPECT TO THE PROPERTY, AND ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS

                                        4

<Page>

FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED BY LESSOR AND EXCLUDED FROM
THIS LEASE. ADDITIONALLY, LESSOR DISCLAIMS ANY WARRANTY OF SUITABILITY THAT
MAY OTHERWISE HAVE ARISEN BY OPERATION OF LAW. LESSOR DOES NOT WARRANT THAT
THERE ARE NO LATENT DEFECTS IN THE PROPERTY OR ANY FACILITIES LOCATED THEREON
THAT ARE VITAL TO LESSEE'S USING THE PROPERTY FOR ITS INTENDED COMMERCIAL
PURPOSE OR THAT THESE ESSENTIAL FACILITIES WILL REMAIN IN A SUITABLE
CONDITION. LESSEE LEASES THE PROPERTY "AS IS" - WHETHER SUITABLE OR NOT - AND
WAIVES THE IMPLIED WARRANTY OF SUITABILITY.

      9. MECHANICS' LIENS. Lessee will not cause or permit any mechanics'
liens or other liens to be filed against the fee of the Property or against
Lessee's leasehold interest in the land or any buildings or improvements on
the Property by reason of any work, labor, services, or materials supplied or
claimed to have been supplied to Lessee or anyone holding the Property or any
part of it through or under Lessee. If such a mechanic's lien or
materialman's lien is recorded against the Property or any buildings or
improvements thereon, Lessee must either cause it to be removed or, if Lessee
in good faith wishes to contest the lien, take timely action to do so, at
Lessee's sole expense. If Lessee contests the lien, Lessee will indemnify
Lessor and hold it harmless from all liability for damages occasioned by the
lien or the lien contest and will, in the event of a judgment of foreclosure on
the lien, cause the lien to be discharged and removed before the judgment is
executed.

      10.   CONDEMNATION.

            (a) PARTIES' INTERESTS. If the Property or any part thereof is
taken for public or quasi-public purposes by condemnation as a result of any
action or proceeding in eminent domain, or is transferred in lieu of
condemnation to any authority entitled to exercise the power of eminent
domain, this Paragraph 10 governs Lessor's and Lessee's interests in the
award or consideration for the transfer and the effect of the taking or
transfer on this Lease.

            (b) TOTAL TAKING - TERMINATION. If the Property is taken in its
entirety or so transferred as described in Subparagraph (a) above, this Lease
and all of the rights, title, and interest under it will cease on the date
that title to the Property or part thereof vests in the condemning authority,
and the proceeds of the condemnation will be divided between Lessor and
Lessee based on the ratio of the fair market value of all Lessee-owned
fixtures and improvements located on the Property to a total value of the
Property and all fixtures and improvements thereon. If the parties cannot
agree on such fair market values, they shall mutually agree on qualified
third party appraisers; one to establish the value of the Property alone and
one experienced in valuing natural gas liquids industry assets to establish
the value of the Lessee-owned fixtures and improvements.

            (c) PARTIAL TAKING - TERMINATION. If only part of the Property is
taken or transferred as described in Subparagraph (a) above, this Lease will
terminate if, in Lessee's opinion, the remainder of the Property is in such a
location - or is in such form, shape, or reduced size - that Lessee's
facilities cannot be effectively and practicably operated on the remaining
Property. In that event, this Lease and all rights, title, and interest under
it will cease on the date that title to the portion of the Property taken or
transferred vests in the condemning authority. The proceeds of the

                                        5

<Page>

condemnation will be divided in the same manner as provided for above;
provided, however, that Lessor's share shall be reduced by the fair market
value of any of the Property retained.

            (d) CONTINUATION WITH RENT ABATEMENT. If part of the Property is
taken or transferred as described in Subparagraph (a) above and, in Lessee's
opinion, the remainder of the Property is in such a location and in such
form, shape, or size that Lessee's business can be effectively and
practicably operated on the remaining portions of the Property, this Lease
will terminate with respect to the portion of the Property taken or
transferred as of the date title to such portion vests in the condemning
authority but will continue in full force with respect to the portion of the
Property not taken or transferred. There shall be no refund or abatement of
rent, in such instance and any proceeds of condemnation shall be shared
between the parties in a manner to be agreed to at that time.

            (e) VOLUNTARY CONVEYANCE. Lessor shall not voluntarily convey all
or part of the Property to a public utility, agency, or authority under
threat of a taking under the power of eminent domain without Lessee's prior
written consent. Any such voluntary conveyance will be treated as a taking
within the meaning of this Paragraph 10.

      11. NOTICES. Any notice or other communication provided for in this
Lease or any notice which either Party may desire to give to the other shall
be in writing and shall be deemed to have been properly given if and when
sent by facsimile transmission, delivered by hand, or if sent by mail, upon
deposit in the United States mail, either U.S. Express Mail, registered mail
or certified mail, with all postage fully prepaid, or if sent by courier, by
delivery to a bonded courier with charges paid in accordance with the
customary arrangements established by such courier, in each case addressed to
the Parties at the following addresses:

                LESSOR:      Warren Petroleum Company, Limited Partnership
                             1000 Louisiana, Suite 5800
                             Houston, Texas 77002-5050
                             ATTN: Vice President, Asset Marketing and Services
                             Telephone: 713-507-3843
                             Telecopier: 713-507-6846

                LESSEE:      Cedar Bayou Fractionators, Limited Partnership
                             c/o Warren Petroleum Company, Limited Partnership
                             1000 Louisiana, Suite 5800
                             Houston, TX 77002-5050
                             ATTN: General Counsel
                             Telephone: 713-507-6400
                             Telecopier: 713-507-6987

                                        6

<Page>

or at such other address as either Party shall designate by written notice to
the other. A notice sent by facsimile shall be deemed to have been received
by the close of the business day following the day on which it was
transmitted and confirmed by transmission report or such earlier time as
confirmed orally or in writing by the receiving Party. Notice by U.S. Mail,
whether by U.S. Express Mail, registered mail or certified mail, or by
overnight courier shall be deemed to have been received by the close of the
second business day after the day upon which it was sent, or such earlier
time as is confirmed orally or in writing by the receiving Party. Any Party
may change its address or facsimile number by giving notice of such change in
accordance herewith.

      12.   FORCE MAJEURE.

      (a)   In the event either Party hereto is rendered unable, wholly or in
            part, by reason of Force Majeure to carry out its obligations under
            this Lease, upon such Party's giving notice and reasonably full
            particulars of such Force Majeure in writing to the other Party
            after the occurrence of the cause relied on, then the obligations of
            such Party, other than the obligation to pay money due hereunder,
            insofar and only insofar as they are affected by such Force
            Majeure, shall be suspended during the continuance of any inability
            so caused, but for no longer period; and such cause shall, so far
            as reasonably possible, be remedied with all reasonable dispatch.

      (b)   The term "Force Majeure" shall mean acts of God, strikes, lockouts
            or other industrial disputes or disturbances, acts of the public
            enemy, wars, blockades, insurrections, riots, epidemics, landslides,
            lightning, earthquakes, fires, tornadoes, hurricanes, storms, and
            warnings for any of the foregoing which may necessitate either Party
            to either act or refrain from acting in a manner that might
            otherwise constitute a breach hereunder, floods, washouts, arrests
            and restraints of governments (either federal, state, civil or
            military), civil disturbances, explosions, sabotage, breakage or
            accidents to equipment, machinery, plants, or any portion thereof,
            or lines of pipe, the making of repairs or alterations to any of the
            foregoing, inability to secure labor or materials, freezing of
            equipment, machinery, plants, or any portion thereof, or lines of
            pipe, partial or entire failure of wells or gas supply, electric
            power shortages, necessity for compliance with any court order, or
            any law, statute, ordinance, rule, regulation or order promulgated
            by a governmental authority having or asserting jurisdiction,
            inclement weather that necessitates extraordinary measures and
            expense to construct facilities and/or maintain operations, or any
            other causes, whether of the kind enumerated herein or otherwise,
            which are not within the reasonable control of the Party claiming
            suspension and which by the exercise of due diligence such Party is
            unable to prevent or overcome. Such term shall likewise include, in
            those instances where either Party hereto is required to obtain
            servitudes, rights-of-way, grants, permits or licenses to enable
            such Party to fulfill its obligations hereunder, the inability of
            such Party to acquire, or delays on the part of such Party in
            acquiring,, at reasonable cost and after the exercise of reasonable
            diligence, such servitudes, rights-of-way grants, permits or
            licenses, and in those instances where either Party hereto

                                        7

<Page>

            is required to furnish materials and supplies for the purpose of
            constructing or maintaining facilities to enable such Party to
            fulfill its obligations hereunder, the inability of such Party to
            acquire, or delays on the part of such Party in acquiring, at
            reasonable cost and after the exercise of reasonable diligence, such
            materials and supplies. The term "Force Majeure" shall also include
            any event of force majeure occurring with respect to the facilities
            or services of either Party's suppliers or customers providing a
            service or providing any equipment, goods, supplies or other items
            necessary to the performance of such Party's obligations, and shall
            also include curtailment or interruption of deliveries or services
            by third-party suppliers or customers as a result of an event
            defined as Force Majeure hereunder.

      (c)   Notwithstanding Subparagraph 12(a) above, it is understood and
            agreed that the settlement of strikes or lockouts shall be entirely
            within the discretion of the Party having the difficulty, and that
            the above requirement that any Force Majeure shall be remedied with
            all reasonable dispatch shall not require the settlement of strikes
            or lockouts by acceding to the demands of the opposing party when
            such course is inadvisable in the discretion of the Party having the
            difficulty.

      13.   ALTERNATIVE DISPUTE RESOLUTION.

      (a)   COVERED DISPUTES- Any dispute, controversy or claim (whether
            sounding in contract, tort or otherwise) arising out of or
            relating to this Lease, including, without limitation, the
            meaning of its provisions, or the proper performance of any of
            its terms by either Party, its breach, termination or invalidity
            ("Dispute") will be resolved in accordance with the procedures
            specified in this Paragraph, which will be the sole and exclusive
            procedure for the resolution of any such Dispute, except that a
            Party, without prejudice to the following procedures, may file a
            complaint to seek preliminary injunctive or other provisional
            judicial relief, if in its sole judgment, that action is
            necessary to avoid irreparable damage or to preserve the status
            quo. Despite the filing of any such injunctive or other
            provisional judicial relief, the Parties will continue, subject to
            Subparagraph (j) below, to participate in the applicable
            procedures specified in this Paragraph. The obligation to
            participate in such applicable procedures shall not require
            either Party to participate in the negotiation between executives
            procedures set forth in Subparagraph (c) below or the mediation
            procedures set forth in Subparagraph (d) below if either Party
            determines, in its sole discretion, that such procedures would be
            futile.

      (b)   INITIATION OF PROCEDURES. Either Party desiring to initiate the
            dispute resolution procedures set forth in this Paragraph with
            respect to a Dispute not resolved in the ordinary course of business
            (the "Initiating Party") must give written notice of the Dispute
            (the "Dispute Notice") to the other Party (the "Non-Initiating
            Party"). The Dispute Notice shall include (i) a statement of that
            Party's position and a summary of

                                        8

<Page>

            arguments supporting that position, and (ii) the name and title of
            the executive who will represent that Party, and of any other person
            who will accompany the executive, in the negotiations under
            Subparagraph (c) below.

      (c)   NEGOTIATION BETWEEN EXECUTIVES - If one Party has given a Dispute
            Notice under Subparagraph (b) above, the Parties may attempt in
            good faith to resolve the Dispute within forty-five (45) days
            following receipt of the Dispute Notice by the Non-Initiating
            Party by negotiation between executives who have authority to
            settle the Dispute and who are at a higher level of management
            than the persons with direct responsibility for administration of
            this Lease or the matter in Dispute. Within fifteen (15) days
            after receipt of the Dispute Notice, the Non-Initiating Party may
            submit to the other a written response. If given, the response
            will include (i) a statement of that Party's position and a
            summary of arguments supporting that position, and (ii) the name
            and title of the executive who will represent that Party and of
            any other person who will accompany the executive. If such a
            response is given by the Non-Initiating Party, within forty-five
            (45) days following receipt of the Dispute Notice by the
            Non-Initiating Party, the executives of both Parties will meet at
            a mutually acceptable time and place, and thereafter, as often as
            they reasonably deem necessary, to attempt to resolve the Dispute.

      (d)   MEDIATION - If the Dispute has not been resolved by negotiation
            under the Subparagraph (c) above within forty-five (45) days
            following receipt of the Dispute Notice by the Non-Initiating Party
            or if the Non-Initiating Party fails to respond within the required
            fifteen (15) day period, either Party may initiate the mediation
            procedure of this Subparagraph by giving written notice to the other
            Party ("Mediation Notice). The Parties will endeavor to settle the
            Dispute by mediation within sixty (60) days of the Mediation Notice
            under the then current Center for Public Resources ("CPR") Model
            Mediation Procedure for Business Disputes. If the Parties have not
            agreed upon a mediator within seven (7) days after the Mediation
            Notice, either Party may request CPR assistance in the selection of
            a mediator under its guidelines. Unless otherwise agreed to by the
            Parties, no discovery shall be allowed during the sixty (60) day
            mediation period. If both Parties elect to participate in the
            mediation procedures set forth herein, the cost of the mediator will
            be shared equally between the Parties, unless otherwise agreed to in
            writing by the Parties. If one Party elects not to participate in
            the mediation procedures, neither Party shall bear any cost
            associated with such procedure, other than costs that each Party may
            have incurred in connection therewith which shall be borne by the
            Party that incurred such costs.

      (e)   ARBITRATION. If the Dispute has not been resolved by mediation under
            the Subparagraph (d) above within the required sixty (60) day period
            or if either Party fails and/or refuses to participate in such
            mediation procedures, either Party may request that the matter be
            resolved through arbitration by submitting a written notice

                                        9

<Page>

            (the "Arbitration Notice") to the other. Any arbitration that is
            conducted hereunder shall be governed by the Federal Arbitration
            Act, 9 U.S.C. Section 1 ET SEQ., as amended, and will not be
            governed by the arbitration acts, statutes, or rules of any other
            jurisdiction.

      (f)   ARBITRATION PROCEDURE. The Arbitration Notice shall name the
            noticing Party's arbitrator and shall contain a statement of the
            issue(s) presented for arbitration. Within fifteen (15) Days of
            receipt of an Arbitration Notice, the other Party shall name its
            arbitrator by written notice to the other and may designate any
            additional issue(s) for arbitration. The two named arbitrators
            shall select the third arbitrator within fifteen (15) Days after
            the date on which the second arbitrator was named. Should the two
            arbitrators fail to agree on the selection of the third
            arbitrator, either Party shall be entitled to request the Senior
            Judge of the United States District Court for the Southern
            District of Texas to select the third arbitrator. Should either
            Party fail and/or refuse to name its arbitrator within the
            required fifteen (15) day period, the other Party shall be
            entitled to request the Senior Judge of the United States
            District Court for the Southern District of Texas to select the
            arbitrator for such Party. All arbitrators shall be qualified by
            education or experience within the natural gas liquids portion of
            the energy industry to decide the issues presented for
            arbitration. No arbitrator shall be: a current or former
            director, officer, or employee of either Party or its Affiliates;
            an attorney (or member of a law firm) who has rendered legal
            services to either Party or its Affiliates within the preceding
            three Years; or an owner of any of the common stock of either
            party, or its Affiliates.

                                        10

<Page>

      (g)   ARBITRATION HEARING. The three arbitrators shall commence the
            arbitration proceedings within twenty-five (25) Days following the
            appointment of the third arbitrator. The arbitration proceedings
            shall be held at a mutually acceptable site and if the Parties are
            unable to agree on a site, the arbitrators shall select the site.
            The arbitrators shall have the authority to establish rules and
            procedures governing the arbitration proceedings, including, without
            limitation, rules concerning discovery. Each Party shall have the
            opportunity to present its evidence at the hearing. The arbitrators
            may call for the submission of pre-hearing statements of position
            and legal authority, but no posthearing briefs shall be submitted.
            The arbitration panel shall not have the authority to award
            incidental, consequential, special, punitive or exemplary damages.
            In addition, if an issue under consideration is limited to a
            determination of an amount of money owed by one Party to the other,
            each Party shall submit to the arbitration panel a final offer of
            its proposed resolution of the dispute. The arbitration panel shall
            be charged to select from the two proposals the one which the panel
            finds to be the most reasonable and consistent with the terms and
            conditions of this Lease, and the arbitration panel shall not
            average the Parties' proposals or otherwise craft its own remedy.
            All evidence submitted in an arbitration proceeding, transcripts of
            such proceedings, and all documents submitted by the Parties in an
            arbitration proceeding shall be kept confidential and shall not be
            disclosed to any third Party by either Party hereto.

      (h)   ARBITRATION DECISION AND COSTS. The decision of the arbitrators or a
            majority of them, shall be in writing and shall be final and binding
            upon the Parties as to the issue(s) submitted. The cost of the
            hearing shall be shared equally by the Parties, and each Party shall
            be responsible for its own expenses and those of its counsel or
            other representatives. Each Party hereby irrevocably waives, to the
            fullest extent permitted by law, any objection it may have to the
            arbitrability of any such disputes, controversies or claims and
            further agrees that a final determination in any such arbitration
            proceeding shall be conclusive and binding upon each Party.

      (i)   ENFORCEMENT OF AWARD. Judgment upon any award rendered by the
            arbitrators may be entered in any court having jurisdiction. The
            prevailing Party shall be entitled to reasonable attorneys' fees in
            any contested court proceeding brought to enforce or collect any
            award of judgment rendered by the arbitrators.

      (j)   TOLLING AND PERFORMANCE. Except as otherwise provided in this
            Paragraph 13, all applicable statutes of limitation and defenses
            based upon the passage of time and all contractual limitation
            periods specified in this Lease, if any, will be tolled while the
            procedures specified in this Paragraph 13 are pending. The Parties
            will take all actions to effectuate necessary to effectuate the
            tolling of any applicable statute of limitation of contractual
            limitation periods. All deadlines specified herein may be extended
            by mutual written agreement of the Parties. Each Party is required
            to continue to perform its obligations under this Lease pending
            final resolution of any

                                        11

<Page>

            Dispute, unless to do so would be impossible or impracticable under
            the circumstances. Notwithstanding the foregoing, the statute of
            limitations of the State of Texas applicable to the commencement of
            a lawsuit will apply to the commencement of an arbitration under
            this Lease, except that no defenses will be available based upon the
            passage of time during any negotiation or mediation called for by
            the preceding Subparagraphs of this Paragraph.

      14. RESTRICTION ON ASSIGNMENT. This Lease or rights therein may not be
pledged, mortgaged, transferred, sublet or assigned in whole or in part by
Lessee without the prior written consent of Lessor, which consent shall not
be unreasonably withheld; except as to the following assignments, which shall
not require Lessor's consent: (i) assignments to a party or parties acquiring
all or substantially all of the assets of Lessee; (ii) assignments or
subletting to Affiliates of Lessee; (iii) encumbrances of the leasehold
estate created hereby to a Lender pursuant to the provisions of Paragraph 7
of this Lease; and (iv) licenses or permits for terms of two (2) years or
less to third parties in connection with Lessee's operations on the Property.
Any attempt to assign this Lease in a manner contrary to the terms of this
Paragraph without Lessor's consent shall be void.

      15. NO COMMISSIONS, FEES OR REBATES. Except as expressly provided in
this Lease, no director, employee or agent of either Party shall give or
receive any commission, fee, rebate gift or entertainment of significant cost
or value in connection with this Lease. Any representative or
representative(s) authorized by either Party may audit the applicable records
of the other Party for the purpose of determining whether there has been
compliance with this Paragraph.

      16. SEVERABILITY. This Lease and the operations hereunder shall be
subject to the valid and applicable federal and state laws and the valid and
applicable orders, laws, local ordinances, rules, and regulations of any
local, state or federal authority having jurisdiction, but nothing contained
herein shall be construed as a waiver of any right to question or contest any
such order, laws, rules, or regulations in any forum having jurisdiction in
the premises. If any provision of this Lease is held to be illegal, invalid,
or unenforceable under the present or future laws effective during the term
of this Lease, (i) such provision will be fully severable, (ii) this Lease
will be construed and enforced as if such illegal, invalid, or unenforceable
provision had never comprised a part of this Lease, and (iii) the remaining
provisions of this Lease will remain in full force and effect and will not be
affected by the illegal, invalid, or unenforceable provision or by its
severance from this Lease. Furthermore, in lieu of such illegal, invalid, or
unenforceable provision, there will be added automatically as a part of this
Lease a provision similar in terms to such illegal, invalid, or unenforceable
provision as may be possible and as may be legal, valid, and enforceable. If
a provision of this Lease is or becomes illegal, invalid, or unenforceable in
any jurisdiction, the foregoing event shall not affect the validity or
enforceability in that jurisdiction of any other provision of this Lease nor
the validity or enforceability in other jurisdictions of that or any other
provision of this Lease.

      17. GOVERNING LAW. THIS AGREEMENT AND THE RIGHTS AND DUTIES OF THE PARTIES
ARISING OUT OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED, ENFORCED, AND
PERFORMED IN ACCORDANCE WITH THE LAWS OF

                                        12

<Page>

THE STATE OF TEXAS, AS THE SAME MAY BE AMENDED FROM TIME TO TIME, WITHOUT
GIVING EFFECT TO ANY CHOICE OR CONFLICT OF LAW PROVISION OR RULE THAT WOULD
CAUSE THE APPLICATION OF THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF
TEXAS.

      18. ENTIRE AGREEMENT AMENDMENT AND WAIVER. This Lease, including
without limitation, all exhibits hereto, integrates the entire understanding
between the Parties with respect to the subject matter covered and supersedes
all prior understandings, drafts, discussions, or statements, whether oral or
in writing, expressed or implied, dealing with the same subject matter. This
Lease may not be amended or modified in any manner except by a written
document signed by both Parties that expressly amends this Lease. No waiver
by either Party hereto of any of the provisions of this Lease shall be deemed
or shall constitute a waiver of any other provision hereof (whether or not
similar) nor shall such waiver constitute a continuing waiver unless
expressly provided. No waiver shall be effective unless made in writing and
signed by the Party to be charged with such wavier.

      19. SETOFFS AND COUNTERCLAIMS. Except as otherwise provided herein,
each Party reserves to itself all rights, set-offs, counterclaims, and other
remedies and/or defenses which such Party is or may be entitled to arising
from or out of this Lease or as otherwise provided by law.

      20. NO PARTNERSHIP, ASSOCIATION, ETC. Nothing contained in this Lease
shall be construed to create an association, trust, partnership, or joint
venture or impose a trust or partnership duty, obligation, or liability on or
with regard to either Party.

      21. EXHIBITS. All Exhibits attached hereto are incorporated herein by
reference as fully as though contained in the body hereof. If any provision of
any Exhibit conflicts with the terms and provisions hereof, the provisions of
this Lease shall prevail.

      22. DTPA WAIVER. EACH PARTY EXECUTING THIS AGREEMENT HEREBY WAIVES ITS
RESPECTIVE RIGHTS, IF ANY, UNDER THE DECEPTIVE TRADE PRACTICES-CONSUMER
PROTECTION ACT, SECTION 17.41 ET SEQ., TEXAS BUSINESS & COMMERCE CODE, A LAW
THAT GIVES CONSUMERS SPECIAL RIGHTS AND PROTECTIONS. AFTER CONSULTATION WITH
AN ATTORNEY OF ITS OWN SELECTION, EACH PARTY EXECUTING THIS AGREEMENT
VOLUNTARILY CONSENTS TO THIS WAIVER. IN ADDITION, EACH PARTY EXECUTING THIS
AGREEMENT HEREBY REPRESENTS AND WARRANTS TO THE OTHER PARTY THAT (i) SUCH
PARTY'S LEGAL COUNSEL WAS NOT DIRECTLY OR INDIRECTLY IDENTIFIED, SUGGESTED,
OR SELECTED BY THE OTHER PARTY OR BY AN AGENT OF SUCH OTHER PARTY, AND (ii)
NEITHER PARTY EXECUTING THIS AGREEMENT IS IN A SIGNIFICANTLY DISPARATE
BARGAINING POSITION.

      23. PRINCIPLES OF CONSTRUCTION AND INTERPRETATION. In construing this
Lease, the following principles shall be followed:

<Page>

      (a)   no consideration shall be given to the fact or presumption that
            one Party had a greater or lesser hand in drafting this Lease;

      (b)   examples shall not be construed to limit, expressly or by
            implication, the matter they illustrate;

      (c)   the word "includes" and its syntactical variants mean "includes,
            but is not limited to" and corresponding syntactical variant
            expressions; and

      (d)   the plural shall be deemed to include the singular and vice
            versa, as applicable.

      24. FURTHER DOCUMENTS. Each Party hereto, upon the request of the other
Party, agrees to perform any further acts and execute and deliver any
documents which may be reasonably necessary to carry out the provisions of
this Lease. Lessor will from time to time and at any reasonable time execute
and deliver to Lessee, when Lessee reasonably requests, other instruments and
assurances approving, ratifying, and confirming this Lease and the leasehold
estate created by it and certifying that the Lease is in full force and that
no default under the Lease on Lessee's part exists. But, if any default on
Lessee's part does exist, Lessor must specify in any such instrument each
such default of which it then has knowledge.

      25. HEADINGS AND PARAGRAPHS. All references to "Paragraphs" and
"Subparagraphs" herein pertain to Paragraphs and Subparagraphs of this
Agreement, unless expressly stated otherwise. Headings are for purposes of
reference only and shall not be used to construe the meaning of this Lease.

      26. NO THIRD PARTY BENEFICIARY. This Lease is for the sole benefit of
the Parties and their respective successors and permitted assigns, and shall
not inure to the benefit of any other person whomsoever, it being the
intention of the Parties that no third person shall be deemed a third Party
beneficiary of this Lease.

      27. RIGHT OF FIRST REFUSAL. In the event Lessor receives an offer to
purchase any of the Property or the Retained Property (the two being
collectively referred to as the "Option Property") and such offer is
acceptable to Lessor, then Lessor shall notify Lessee in writing of the terms
and conditions offered by such third party and shall offer to sell that
portion of the Option Property covered by the offer to Lessee for the same
consideration and on the same terms and conditions as offered by the third
party. Lessee shall have ten (10) business days after its receipt of Lessor's
notice to accept Lessor's offer and if Lessee rejects or otherwise fails to
accept the offer within such time, then Lessor shall be entitled to sell the
property to such third party in accordance with the offer; provided, however,
that if such sale is not consummated within ninety (90) days after the end of
Lessee's period for accepting Lessor's offer under this Paragraph or if the
terms and conditions of the sale to such third party are materially altered
after the expiration of Lessee's period for accepting Lessor's offer, then
Lessee's rights of first refusal hereunder shall be reinstated and Lessor
shall be required to again notify Lessee of the terms and conditions offered

                                      14

<Page>

by that same or any other third party for the purchase of all or any portion
of the Option Property. Lessee's above stated right of first refusal option
under this Paragraph shall not apply to any sale by Lessor to any of its
Affiliates, nor to a sale of all of the assets of Lessor. However, the right
of first refusal option granted hereunder shall be a vested and continuing
right of Lessee that shall survive any transfer of title to all or any
portion of the Option Property (including transfers to any of Lessor's
Affiliates) and both the initial and any subsequent transferee or grantee of
Lessor's title therein shall be required to comply with the provisions of this
Paragraph as to any subsequent transfers of title to any portion of the
Option Property.

      IN WITNESS WHEREOF, the parties hereto have executed this agreement in
multiple originals to be effective as of the date set forth in Paragraph 2.

ATTEST:                            WARREN PETROLEUM COMPANY,
                                   LIMITED PARTNERSHIP
____________________________       BY: _______________________________________
                                   Name: _____________________________________
                                   Title: ____________________________________

                                   CEDAR BAYOU FRACTIONATORS, L.P.

                                   BY: Downstream Energy Ventures Co., L.L.C.,
                                       Managing General Partner

                                       By: ___________________________________
                                       Name: _________________________________
                                       Title:

                                      15

<Page>

                                ACKNOWLEDGMENTS

STATE OF TEXAS

COUNTY OF HARRIS

      On this      day of         , 1997, before me appeared             to
me personally known, being by me duly sworn, did say that he is the
of WARREN PETROLEUM G.P. INC., general partner of WARREN PETROLEUM COMPANY,
LIMITED PARTNERSHIP, and that said instrument was signed on behalf of said
corporation by authority of its Board of Directors, and he acknowledged said
instrument to be the free act and deed of said corporation and said
partnership.

      SWORN TO AND SUBSCRIBED before me,            , 1997.

                                                 -----------------------------
My Commission expires:                                    Notary Public

----------------------------------

STATE OF TEXAS

COUNTY OF HARRIS

      On this      day of         , 1997, before me appeared             , to
me personally known, being by me duly sworn, did say that he is the
of DOWNSTREAM ENERGY VENTURES, L.L.C., managing general partner of CEDAR
BAYOU FRACTIONATORS, L.P., a Delaware limited partnership, and that said
instrument was signed on behalf of said corporation by authority of its Board
of Directors, and he acknowledged said instrument to be the free act and deed
of said corporation and said partnership.

      SWORN TO AND SUBSCRIBED before me,            , 1997.

                                                 -----------------------------
My Commission expires:                                    Notary Public

----------------------------------

                                      16

<Page>

                                    EXHIBIT A

                                  THE PROPERTY

SURFACE LEASE AREA:

THE USE OF THE SURFACE ONLY AS TO THE FOLLOWING AREA: That area described in
the metes and bounds description attached hereto and certified by Robert L.
Hall, Registered Professional Land Surveyor No. 1610, dated December 12,
1997, which is incorporated herein by reference.

WATER RIGHTS AREA:

LESSEE IS GRANTED THE RIGHT TO WITHDRAW ANY WATER REQUIRED FOR ITS OPERATIONS
ON THE ABOVE SURFACE LEASE AREA ONLY, AND IN ACCORDANCE WITH ALL APPLICABLE
LAWS AND REGULATIONS, FROM AND THROUGH THE THREE EXISTING WATER WELLS OWNED
BY LESSOR ON THE FOLLOWING DESCRIBED TRACTS, AND SHALL MAINTAIN AND OPERATE
SAID WELLS DURING THE TERM HEREOF, AND SHALL HAVE USE OF SO MUCH OF THE
SURFACE OF THE BELOW TRACTS AS IS REASONABLY NECESSARY TO OPERATE AND
MAINTAIN SAID WATER WELLS, TOGETHER WILL FULL RIGHT OF INGRESS AND EGRESS
THERETO OVER AND ACROSS ALL EXISTING ROADWAYS AND PATHS LEADING TO SAID WATER
WELLS IN THE SAME MANNER AS SET FORTH IN PARAGRAPH 3(c) IN THE LEASE:

WATER WELLS #1 AND #2

That certain tract of land containing 6.97 acres, more or less, located in
Chambers County, Texas identified as Tract 16 on that certain plat prepared
by BUSCH, HUTCHISON & ASSOCIATES, INC. and recorded in the Map Records of
Chambers County, Texas in Volume B, Page 127; said tract being conveyed from
NGC CORPORATION, formerly known as Midstream Combination Corp. to Warren
Petroleum Company, Limited Partnership in that DEED, ASSIGNMENT AND
CONVEYANCE recorded in Volume 308 at Page 623 of the Official Public Records
of Chambers County, Texas.

WATER WELL #3

That certain tract of land containing 3.318 acres, more or less, located in
Chambers County, Texas identified as Tract 1 on that certain plat prepared by
BUSCH, HUTCHISON & ASSOCIATES, INC. and recorded in the Map Records of
Chambers County, Texas in Volume B, Page 126; said tract being conveyed from
NGC CORPORATION, formerly known as Midstream Combination Corp. to Warren
Petroleum Company, Limited Partnership in that DEED, ASSIGNMENT AND
CONVEYANCE recorded in Volume 308 at Page 623 of the Official Public Records
of Chambers County, Texas.

                                      17

<Page>

STATE OF TEXAS)
COUNTY OF CHAMBERS)

FIELD NOTES of a 53.880 acre tract of land situated in the William Bloodgood
League, Abstract Number 4, Chambers County, the Henry Griffith League,
Abstract Number 12, Chambers County, the William Bloodgood Augmentation
Survey, Abstract Number 5, Chambers County, and being out of and a part of a
242.5057 acre tract of land called Tract 9 and conveyed to Midstream
Combination Corp. by Chevron U.S.A. Inc., in deed dated August 20, 1996, and
recorded in Volume 308 at Page 85 of the Official Public Records of Chambers
County. This 53.880 acre tract of land is more particularly described by
metes and bounds as follows, to-wit:

NOTE: ALL BEARINGS ARE LAMBERT GRID BEARINGS AND ALL COORDINATES REFER TO THE
STATE PLANE COORDINATE SYSTEM, SOUTH CENTRAL ZONE, AS DEFINED BY ARTICLE
21.071 OF THE NATURAL RESOURCES CODE OF THE STATE OF TEXAS, 1927 DATUM. ALL
DISTANCES ARE ACTUAL DISTANCES. REFERENCE IS MADE TO PLAT OF EVEN DATE
ACCOMPANYING THIS METES AND BOUNDS DESCRIPTION.

BEGINNING at a brass cap set in concrete for the Northeast corner of this
tract of land, having a State Plane Coordinate Value of Y = 752,799.30 and X
= 3,299,929.27. From this beginning corner a 1 1/4 inch iron pipe found for
the Northeast corner of said Bloodgood League, an interior corner of the
Henry Griffith League, Abstract Number 12, Chambers County, an angle point in
the North line of said 242.5057 acres, and an angle point in the South line
of a tract of land conveyed to Texas Eastern Transmission Corporation by
0. Z. Smith, et ux, in deed dated January 3, 1959, and recorded in Volume 227
at Page 201 of the Deed Records of Chambers County bears North 15 DEG. 06' 33"
West a distance of 1245.27 feet.

THENCE in a Southerly direction with the East line of this tract of land the
following courses to brass caps set in concrete:

        South 15 DEG. 19' 31" East  495.89 feet;
        North 79 DEG. 11' 30" East   39.03 feet;
        South 13 DEG. 05' 10" East   72.16 feet;
        South 74 DEG. 48' 00" West   36.40 feet;
        South 15 DEG. 20' 53" East 1099.45 feet to a brass cap set
in concrete for the Southeast corner of this tract of land.

THENCE South 76 DEG. 53' 10" West with the South line of this tract of land a
distance of 1149.43 feet to a brass cap set in concrete for the Southwest
corner of this tract of land, in the West line of said 242.5057 acres, and
in the East line of a 25.28 acre tract of land called First Tract and
conveyed to Exxon Pipeline Corporation in Partition Deed dated July 22, 1971,
and recorded in Volume 326 at Page 646 of the Deed Records of Chambers County.

<Page>

PAGE NO. 2 - 53.880 ACRES

THENCE North 11 DEG. 44' 58" West with the West line of this tract of land,
the West line of said 242.5057 acres, and the East line of said 25.28 acres a
distance of 626.28 feet to a brass cap set in concrete for an interior corner
of this tract of land, an interior corner of said 242.5057 acres, and the
Northeast corner of said 25.28 acres.

THENCE South 76 DEG. 49' 25" West with the a South line of this tract of
land, a South line of said 242.5057 acres, and the North line of said 25.28
acres a distance of 152.77 feet to a brass cap set in concrete for the most
Northerly Southwest corner of this tract of land.

THENCE in a Westerly and Northerly direction with the West line of this tract
of land the following courses to brass caps set in concrete:

          North 19 DEG. 42' 27" East  81.08  feet;
          North 13 DEG. 03' 18" West 228.62  feet;
          South 76 DEG. 56' 42" West 278.41  feet;
          South 13 DEG. 03' 18" East  77.07  feet;
          South 76 DEG. 56' 42" West 133.07  feet;
          North 13 DEG. 03' 18" West 314.52  feet;
          South 76 DEG. 56' 42" West 171.52  feet;
          North 13 DEG. 03' 18" West 350.11  feet to a brass
cap set in concrete for the Northwest corner of this tract of land, in a
non-tangent curve to the right.

THENCE in a Northeasterly direction with the North line of this tract of land
and said non-tangent curve to the right, concave Southeast, having a central
angle of 18 DEG. 33' 33", a radius of 1185.34 feet, an arc length of 383.95
feet, and a chord bearing and distance of North 53 DEG. 10' 11" East 382.28
feet to a brass cap set in concrete for a corner of this tract of land and
the end of said curve.

THENCE in an Easterly direction with the North line of this tract of land the
following courses to brass caps set in concrete:

          North 72 DEG. 12' 42" East  106.35 feet;
          North 74 DEG. 27' 33" East   93.65 feet;
          North 77 DEG. 15' 59" East 1211.38 feet to the PLACE OF
BEGINNING, containing within said boundaries 53.880 acres of land.

SURVEYED: December 8, 1997.

<Page>

PAGE NO. 2 - 53.880 ACRES

                             SURVEYOR'S CERTIFICATE

I, Robert L. Hall. Jr., Reg Professional Land Surveyor No. 1610, do hereby
certify that the foregoing field notes were prepared from an actual survey
made on the ground on the date shown and that all lines, boundaries and
landmarks are accurately described therein.

WITNESS my hand and seal at Baytown, Texas, this the 12th., day of December,
A.D., 1997.

/s/ Robert L. Hall, Jr.
REG. PROFESSIONAL LAND SURVEYOR
NO. 1610
97-1388H.FDN

[SEAL]

<Page>

                                   EXHIBIT E
                                      TO
                        LIMITED PARTNERSHIP AGREEMENT

                       PARTNER FRACTIONATION AGREEMENTS

<Page>

                             FRACTIONATION AGREEMENT

                                 by and between

                         CEDAR BAYOU FRACTIONATORS, L.P.

                                       and

                               AMOCO OIL COMPANY.

                            EFFECTIVE JANUARY 1, 1998
<Page>

                               TABLE OF CONTENTS

<Table>
<Caption>
                                                                            Page
                                                                            ----
<S>                                                                         <C>
ARTICLE I: DEFINITIONS ...................................................    1

ARTICLE II: TERM .........................................................    4

ARTICLE III: AMOCO'S PERFORMANCE .........................................    4

ARTICLE IV: CBF'S PERFORMANCE ............................................    5

ARTICLE V: TRANSFER OF CUSTODY ...........................................    7

ARTICLE VI: MEASUREMENT ..................................................    7

ARTICLE VII: COMPENSATION TO CBF .........................................    7

ARTICLE VIII: TAXES AND OTHER PAYMENTS ...................................    9

ARTICLE IX: ACCOUNTING AND AUDIT PROCEDURES ..............................    9

ARTICLE X: BILLING AND PAYMENT ...........................................   10

ARTICLE XI: FORCE MAJEURE ................................................   11

ARTICLE XII: INDEMNIFICATION AND LIMITATION OF LIABILITY .................   12

ARTICLE XIII: DISPUTE RESOLUTION .........................................   13

ARTICLE XIV: MISCELLANEOUS ...............................................   16

EXHIBIT "A" - AMOCO'S DEDICATED PLANTS

EXHIBIT "B" - SPECIFICATION PRODUCTS SPECIFICATIONS
</Table>

<Page>

                             FRACTIONATION AGREEMENT

     THIS AGREEMENT (the "Agreement") is made and entered into as of the 1st
Day of January, 1998, by and between, Cedar Bayou Fractionators, L.P., a
Delaware limited partnership (hereinafter referred to as "CBF"), and Amoco
Oil Company, a Delaware corporation (hereinafter referred to as "Amoco"),
sometimes also referred to individually as "Party" and collectively as
"Parties."

     WITNESSETH:

     WHEREAS, Amoco owns, controls or has rights to certain volumes of
natural gas liquids recovered by various natural gas processing facilities
available for fractionation; and

     WHEREAS, CBF owns a Fractionation Facility, hereinafter defined,
situated in Mont Belvieu, Chambers County, Texas; and

     WHEREAS, Amoco has arranged for the transportation and delivery of such
Raw Product, hereinafter defined, and/or Butane-Gasoline Mix, hereinafter
defined, to Mont Belvieu, Texas; and

     WHEREAS, CBF has arranged for the receipt of such Raw Product and/or
Butane-Gasoline Mix from Amoco, as well as Raw Product and/or Butane-Gasoline
Mix owned by third parties, at the Delivery Point, hereinafter defined; and

     WHEREAS, it is the mutual desire of CBF and Amoco that CBF receive
Amoco's Raw Product at the Delivery Point and redeliver to Amoco, or its
designee, Specification Products, hereinafter defined, at the Storage
Facility, hereinafter defined, or at other mutually agreeable locations.

     NOW THEREFORE, in consideration of the premises and the mutual covenants
and agreements herein contained, the parties hereto agree as follows:

                             ARTICLE I: DEFINITIONS

     When the following terms or expressions are used in this Agreement, they
shall have the meanings defined below:

     "AFFILIATE" shall mean a Person that directly or indirectly through one or
     more intermediates, controls, or is controlled by or is under common
     control with the Person specified. The term "control" (including the terms
     "controlled by" or "under common control with") means the possession,
     directly or indirectly, of the power to direct or cause the direction of
     the management and policies of a Person, whether through ownership, by
     contract, or otherwise. Any Person shall be deemed to be an Affiliate of

                                       1
<Page>

     any specified Person if such Person owns 50% or more of the voting
     securities of the specified Person, if the specified Person owns fifty
     percent (50%) or more of the voting securities of the specified Person, if
     the specified Person owns fifty percent (50%) or more of the voting
     securities of such Person, or if fifty percent (50%) or more of the voting
     securities of the specified Person and such Person are under common
     control.

     "BACK-END MIX" shall mean any mixture of Components which will be
     fractionated by the Fractionation Facility without requiring the use of the
     Fractionator's de-ethanizer.

     "BACK-END FEE" shall have the meaning as ascribed to it in Article VII.

     "BARREL" shall mean 42 Gallons.

     "BASE RATE" shall have the meaning as ascribed to in it Article X.

     "BUSINESS DAY" shall mean a Day on which Federal Reserve member banks in
     New York City are open for business.

     "CLAIMS" shall have the meaning as ascribed to in Section 12.1 hereinafter.

     "COMPONENT" shall mean the individual hydrocarbon constituents of Raw
     Product, including but not limited to: methane, ethane, propane, isobutane,
     normal butane, isopentane, normal pentane, hexanes and heavier, as well as
     other non-hydrocarbon Components allowed by Pipeline.

     "DAY" OR "DAILY" shall mean a twenty-four (24) hour period commencing 7:00
     a.m. Central Standard or Daylight Savings time, as applicable, and
     extending until 7:00 a.m. Central Standard or Daylight Savings time, as
     applicable, on the following Day.

     "DELIVERY POINT" shall mean the point of interconnection between the
     Pipelines and Storage Facility at which point Amoco's Raw Product is
     delivered to CBF through the Storage Facility.

     "FEE RE-DETERMINATION ARBITRATION" shall have the meaning set forth in
     Section 13.5.

     "FINAL OFFERS" shall mean final offers made by the Parties prior to
     submission of a monetary dispute to an arbitrator, in the manner specified
     in Section 13.7.

     "FORCE MAJEURE" shall have the meaning as ascribed to it in Article XI.

     "FRACTIONATION FACILITY" OR "FRACTIONATOR" shall mean the fractionation
     unit owned by CBF situated in the vicinity of Mont Belvieu, Chambers
     County, Texas, which is operated by Warren which fractionation unit is used
     for the purpose of fractionating Raw Product streams into Specification
     Products.

                                       2
<Page>

     "GALLON" shall mean the unit of volume used for the purpose of measurement
     of liquid. One U. S. liquid Gallon contains 231 cubic inches when the
     liquid is at a temperature of 60 degrees Fahrenheit and at the vapor
     pressure of the liquid being measured.

     "KOCH COMMITMENT" shall mean that volume of Raw Product committed by Amoco
     to Koch Hydrocarbons Company ("Koch") under an agreement effective July 1,
     1997.

     "MONT BELVIEU AREA" shall mean the geographical area surrounding Mont
     Belvieu, Texas including the following Texas counties:

                    Brazoria                         Harris
                    Chambers                         Jefferson
                    Fort Bend                        Liberty
                    Galveston                        Montgomery

     However, the following facilities shall be excluded from the Mont Belvieu
     Area:

        Amoco's refinery and chemical plant in the vicinity of Texas City, Texas
        Amoco's chemical plant in the vicinity of Alvin, Texas
        Amoco's chemical plant in the vicinity of Pasadena, Texas
        Amoco's chemical plant in the vicinity of Mont Belvieu, Texas

     "MONTH" OR "MONTHS" OR "MONTHLY" shall mean the period commencing on the
     first Day of a Month and ending on the first Day of the next succeeding
     Month.

     "PIPELINE(S)" shall mean any pipeline which delivers Amoco's Raw Product to
     the Storage Facility. Currently, the four (4) pipelines capable of
     delivering such Raw Product are the Seminole Pipeline, the Chaparral
     Pipeline, the West Texas Pipeline, and Black Lake Pipeline. During 1998,
     CBF desires to connect to the Dean Pipeline which is owned and operated by
     Duke Energy.

     "PRIMARY TERM" shall have the meaning as ascribed to it in Article II.

     "RAW PRODUCT" shall mean that mixture of liquid hydrocarbons delivered by
     Pipelines to the Storage Facility in accordance with the terms of any
     connection agreements or pipeline tariffs in effect from time to time.

     "REDELIVERY POINT" shall mean the Storage Facility owned and operated by
     Warren.

     "SPECIFICATION PRODUCT(S)" shall mean the liquid hydrocarbons meeting the
     specifications provided for in Exhibit "B", attached hereto, fractionated
     from the Raw Product.

     "STORAGE FACILITY" shall mean the underground storage facilities owned and
     operated by

                                       3
<PAGE>

                       'Confidential Treatment Requested'

     Warren at or near Mont Belvieu, Chambers County, Texas, including, but not
     limited to, all storage caverns, related surface and subsurface equipment,
     and loading and unloading terminals.

     "WARREN" shall mean Warren Petroleum Company, Limited Partnership.

     "YEAR" OR "YEARLY" shall mean a period of 365 consecutive Days; provided,
     however that any Year which contains the date of February 29 shall consist
     of 366 consecutive Days.

     "Y-GRADE" shall mean any Raw Product which will be fractionated by CBF's
     fractionation facility other than Back-End Mixes.

     "Y-GRADE FEE" shall have the meaning as ascribed to it in Article VII.

                                ARTICLE II: TERM

     This Agreement shall have a primary term commencing on January 1, 1998 and
* ending [REDACTED] (the "Primary Term") and shall continue in effect from Year
  to Year thereafter; provided that either Party shall have the right to
  terminate this Agreement effective at the end of the Primary Term or any
  Yearly anniversary thereafter by giving the other Party at least twelve
  Months prior written notice.

                        ARTICLE III: AMOCO'S PERFORMANCE

3.1  Except as set-forth in Section 3.2, Amoco shall deliver or cause to be
     delivered to the Delivery Point for fractionation under the terms of the
     Agreement, the Raw Product which it owns and/or controls and which are
     produced from the dedicated plants listed in Exhibit "A", and which are
     delivered to the Mont Belvieu Area. Such Raw Product shall include both
     Y-Grade and Back-End Mixes. Volumes of Raw Product from the dedicated
     plants listed in Exhibit "A" but which are currently subject to the Koch
     Commitment will be delivered to CBF following the termination of that
     commitment. Amoco further agrees that for any volumes of Y-Grade or
     Back-end Mixes that Amoco may now or in the future have available from
     plants that are not listed in Exhibit "A" and that are delivered to the
     Mont Belvieu Area and that can economically be delivered and fractionated
     at CBF versus alternative opportunities, that Amoco will offer such volumes
     to become dedicated to CBF and that if CBF accepts same, then such volumes
     shall become dedicated under the terms of this Agreement.

3.2  The following volumes shall be excepted from the dedication set-forth in
     Section 3.1 above.

     (1)  Amoco volumes which are dedicated under the Koch Commitment shall not
          be

                                       4
<Page>

                       'Confidential Treatment Requested'

          dedicated to CBF until July 1, 1998.

     (2)  Amoco volumes which are delivered to the Mont Belvieu Area via Duke
          Energy's pipeline, which moves Raw Product from the Matagorda County,
          Texas to Mont Belvieu, Texas (formerly referred to as the Dean
          Pipeline) shall not be dedicated until the following conditions are
          met.

          (a)  A pipeline connection is operational that will allow deliveries
               from the Duke Energy pipeline to CBF's fractionation facility.

          (b)  The Amoco volume on said pipeline is not dedicated under any
               third-party agreement that is in existence at the time that item
               (a) occurs.

     (3)  Volumes from Amoco's Old Ocean Plant located in Brazoria Country,
          Texas.

     (4)  Volumes from Apache's Hastings Plant located in Brazoria Country,
          Texas.

     (5)  Volumes from Exxon's Katy Plant located in Waller County, Texas.

     (6)  Any Amoco volumes which CBF does not commit to accept under the
          provisions of Article IV of this Agreement.

3.3  Amoco shall direct Pipeline to prepare, during each Month, an allocation of
     ownership of the Pipeline's commingled Raw Product, by Components actually
     delivered to CBF. Amoco and CBF are to accept and rely on such allocation.

3.4  Prior to the beginning of each Month, CBF will estimate the volumes of
     Specification Products for which disposition instructions will be required
     from Amoco. Such estimates will be established by utilizing the actual
     volumes of Raw Product delivered to the Fractionation Facility during the
     most recent Month for which actual volumes are available and adjusting for
     anticipated variances as may be advised by Amoco from time to time. As set
     forth in Article IX of this Agreement, Amoco and CBF shall exchange and
     reconcile Monthly statements detailing Amoco's product movement no later
     than the last Day of each succeeding Month following the Month in question.

3.5  Amoco is procuring the fractionation services under this Agreement for the
     purpose of fractionating Raw Product and not for the purpose of reselling
     such services and agrees not to so resell said services.

                          ARTICLE IV: CBF'S PERFORMANCE

4.1  CBF shall accept delivery of and provide fractionation for a maximum of
*    [REDACTED] Barrels per Day of Amoco's Y-Grade and [REDACTED] Barrels per
     Day of Back-End Mixes as determined on a Monthly average basis. Volumes
     above these amounts will be accepted by CBF for fractionation on a space
     available basis.

                                       5
<Page>

4.2  CBF shall deliver Specification Products to Amoco or its designee at the
     Storage Facility or at other mutually agreed upon locations. CBF will
     redeliver Specification Products during the same Month in which the Raw
     Product containing such Components is delivered to CBF, so long as Pipeline
     deliveries allow for fractionation of said Raw Product at a rate
     approximating the Daily average Pipeline delivery rate for said Month.

4.3  CBF shall not routinely hold back Specification Products from Amoco as a
     minimum inventory requirement. However, CBF shall have the right to
     withhold distribution of Amoco's Specification Products, on a CBF ownership
     percentage basis, to the extent that CBF has insufficient volumes of
     Specification Products to meet its obligations to its fractionation
     customers. To determine Amoco's ownership percentage in CBF, the combined
     ownership percentage of both Amoco MB Fractionation Company (a partner in
     CBF) and Amoco MBF Company (a partner in DEVCO) shall be considered.

4.4  The quantity of the five Specification Products due Amoco will be as
     follows, based on the Pipelines' reported volumes of each Component which
     have been delivered for Amoco's account:

     (1)  EP MIX (80/20): the volume will be equal to (a) 100% of the ethane
          Component plus methane Component up to 1.5 liquid volume percent of
          the ethane Component, (b) plus propane Component equal to 25% of the
          volume in (a) above.

     (2)  PROPANE: the volume will be equal to 100% of the propane Component
          minus the propane use for the EP Mix.

     (3)  ISOBUTANE: the volume will be equal to 100% of the isobutane
          Component.

     (4)  NORMAL BUTANE: the volume will be equal to 100% of the normal butane
          Component.

     (5)  NATURAL GASOLINE: the volume will be equal to 100% of the isopentane
          and heavier Components.

4.5  In the event CBF actually produces purity ethane utilizing its existing
     facilities (as of January 1, 1998), then Amoco reserves the right to
     receive a prorated share of its ethane as purity ethane. The maximum
     Monthly volume of purity ethane that Amoco may elect to receive would be
     calculated as follows:

     AE = [AEY/TEY] x E

     Where:
     AE = Amoco's prorated share of purity ethane
     AEY = the ethane Component of Amoco's delivered Y-Grade during the

                                       6
<Page>

                       'Confidential Treatment Requested'

               calendar Month
     TEY = the total amount of ethane Component in Y-Grade delivered to the
               Fractionator for fractionation services during the Calendar Month
     E = the volume of purity ethane produced by CBF during the calendar Month

                         ARTICLE V: TRANSFER OF CUSTODY

     Amoco warrants that it has the right to cause the Raw Product to be
fractionated. Custody of the Raw Product shall transfer to CBF at the Delivery
Points, subject to Amoco's right, pursuant to Section 4.2 above, to receive
allocated Gallons of Specification Products at the Storage Facility. Custody of
Specification Products shall be delivered to Amoco or its designee. CBF shall at
no time take title to the Raw Product or the resulting Specification Products
while such products are in the custody of CBF.

                             ARTICLE VI: MEASUREMENT

6.1  Volumes of Raw Product, shall be measured and calculated in accordance with
     the then current Pipeline tariff or CBF's Pipeline connection agreements.
     CBF shall furnish Amoco with current copies of all Pipeline connection
     agreements and any future modifications to such agreements.

6.2  Volumes of Specification Products delivered by CBF in accordance with
     Article IV, shall be measured and calculated in accordance with CBF's
     standard measurement procedures at Mont Belvieu and shall conform to good
     measurement practices in the industry and the then current API Manual of
     Petroleum Measurement Standards. CBF shall furnish Amoco with the current
     copies of all standard measurement procedures for Mont Belvieu and any
     future modifications to such procedures.

                        ARTICLE VII: COMPENSATION TO CBF

7.1  Subject to Article VIII, as full consideration for the fractionation
     services provided hereunder, Amoco shall pay to CBF a fractionation fee for
     each Gallon of Y-Grade ("Y-Grade Fee") or Back-End Mixes ("Back-End Fee")
     delivered by, or on behalf of, Amoco to CBF each Month. Such fees shall be
     determined on a calendar quarter basis by the following formulas:

*    Y-Grade Fee = [REDACTED]

                    and

                                       7
<Page>

                       'Confidential Treatment Requested'

*    Back-End-Fee = [REDACTED]

Where:

         FUEL   = The fuel cost (in $/MMBtu) equivalent to the Houston Ship
                  Channel Index of INSIDE FERC'S GAS MARKET REPORT, for natural
                  gas (large packages) for the preceding calendar quarter
*                 plus [REDACTED] per MMBTU.

         ELEC   = The combined average cost of purchased electricity (in
                  CENTS/KWH) at the Fractionator for the preceding calendar
                  quarter.

         CPIU   = The combined average Consumer Price Index, as published by
                  the United States Department of Labor, for the preceding
                  calendar quarter.

7.2  The above fee formulas shall remain in effect during the first five Years
     of the Primary Term unless CBF implements a significant energy reduction
     project similar to that contemplated by Warren and Amoco in December of
     1997. If such project is implemented and significant energy consumption
     efficiencies are realized due to same, then CBF and Amoco will mutually
     agree upon a new formula to become effective with the start of the first
     Month that follows the start-up of said project by 60 Days. Such new
     formula should initially reflect the same resulting fees as the above
     formulas, but will utilize new factors as are appropriate to be changed to
     reflect the change in energy consumption patterns at the Fractionator,
     provided that the definition of "FUEL," "ELEC" and "CPIU" above shall not
     change.

7.3  Either Party shall have the right to initiate a renegotiation of either or
     both of the above fees and fee formulas to be effective on any or each of
*    the [REDACTED] of the Effective Date (the "Price Change Dates") by giving
     the other Party at least ninety (90) Days and no more than one hundred
     fifty (150) Days notice prior to any of the Price Change Dates. Such
     negotiations shall commence immediately upon the date of receipt of such
     notice by the other Party and continue for at least sixty (60) Days
     thereafter (the "Negotiation Period"). During the Negotiation Period, each
     Party shall submit to the other Party one or more written offers for the
     new fee or fees. If CBF and Amoco are unable to agree to the new fee or
     fees by the end of the Negotiation Period, either CBF or Amoco shall have
     the right to have the new fee or fees re-determined by initiating Fee
     Re-Determination Arbitration pursuant to Sections 13.5 through 13.10,
     provided that in arbitrating such fee re-determinations, the arbitrator's
     choice shall be based on a determination of which of the Parties' Final
     Offers most closely approximates the then current fair market rate for the
     fractionation and other services provided by CBF hereunder, based on a
     five Year term for volumes and composition of Raw Product similar

                                       8

<Page>

     to that then being tendered hereunder by Amoco, and with the market area
     for comparison being the Mont Belvieu Area.

                     ARTICLE VIII: TAXES AND OTHER PAYMENTS

     Amoco shall be responsible for the payment of any royalties, overriding
royalties, and other payments due or to become due on the Raw Products or the
Specification Products which are subject to this Agreement. Any tax applicable
to the Raw Products or the Specification Products or the services provided by
CBF hereunder, including but not limited to any tax applicable to stored volumes
of Specification Products, shall be borne and paid by Amoco unless such tax is
by law imposed upon CBF, in which event, such tax shall be paid by CBF and
charged to Amoco and reimbursed by Amoco. Amoco shall indemnify and hold CBF and
their respective Affiliate's directors, officers, agents and employees harmless
from and against any and all claims, demands or causes of action of any kind,
together with all loss, damage and expense (including court costs and attorney's
fees) arising with respect to the payment of any taxes, royalties, overriding
royalties and other payments due or to become due on the services, Raw Products
or Specification Products which are subject to this Agreement.

                   ARTICLE IX: ACCOUNTING AND AUDIT PROCEDURES

9.1  Amoco or its designee shall furnish the following reports to CBF: (i)
     Amoco's share of Components in the Raw Product delivered each Month for the
     Month in question by the tenth Day of the next succeeding Month; (ii)
     instructions for delivery of Specification Products for the Month in
     question during the Month in question, as set forth in Section 3.4; and
     (iii) twelve (12) Month forecast of Raw Product projected to be delivered
     under this Agreement, as requested by CBF from time to time.

9.2  CBF shall furnish each Month for the preceding Month, the following reports
     to Amoco: (i) volumes of Amoco's Specification Products attributable to the
     Raw Product delivered to CBF each Month, in accordance with the
     reconciliation described in Section 3.4; (ii) Specification Products
     volumes delivered to Amoco or its designee each Month in accordance with
     the reconciliation described in Section 3.4; and (iii) Amoco's inventories
     of Specification Product(s) each Month, in accordance with the
     reconciliation described in Section 3.4. CBF shall furnish initial reports
     of these items by the twentieth Day of the Month succeeding the Month and
     shall fully complete volume and money reconciliations as described in
     Section 9.3 below.

9.3  Volume and money reconciliation shall be prepared by Amoco and by CBF on a
     Monthly basis. Amoco and CBF shall cooperate to identify and reconcile
     volume balances and amounts owed. As each Party completes each Month's
     reconciliation, a copy of the reconciliation shall be sent to the other
     Party but no later than the last Day of the Month succeeding the Month in
     question.

9.4  All invoices or statements issued by CBF and any volume and money
     reconciliation reports, or balancing reports, during any calendar Year
     shall conclusively be presumed to be true

                                       9
<Page>

     and correct after twenty-four (24) Months following the end of any such
     calendar Year, unless within the said twenty-four (24) Month period the
     other Party takes written exception thereto and makes claim on the Party
     issuing the invoice, statement or report for adjustment.

9.5  Amoco, upon at least thirty (30) Days prior notice in writing to CBF, shall
     have the right to audit the CBF's records pertaining to performance under
     this Agreement, for any calendar Year within the twenty-four (24) Month
     period following the end of such calendar Year; provided, however, the
     making of ail audit shall not extend the time for the taking of written
     exception to and the adjustments provided for in Section 9.4. Amoco shall
     make every reasonable effort to conduct an audit in a manner which will
     result in a minimum of inconvenience to CBF. CBF shall bear no portion of
     the Amoco's audit cost. An audit shall not be conducted more than once each
     Year. CBF shall reply in writing to an audit report within 180 Days after
     receipt of such report. Should Amoco and CBF fail or be unable to resolve
     any audit disputes, the matter shall be resolved using the dispute
     resolution procedures set forth in Article 13 of this Agreement.

9.6  CBF shall retain all financial and volume records for a minimum of
     forty-eight (48) Months following the end of any calendar Year.

                         ARTICLE X: BILLING AND PAYMENT

     After receiving allocation information from Pipeline each Month, CBF shall
furnish Monthly to Amoco an invoice reflecting all applicable fees and charges
due and Amoco shall pay to CBF the amounts due no later than (i) ten (10) Days
after Amoco's receipt of invoice therefor, if the amount of same is fifty
thousand dollars ($50,000) or more or (ii) fifteen (15) Days after receipt of
invoice therefor, if the amount of same is less than fifty thousand dollars
($50,000). If the Day on which any payment is due is not a Business Day, then
the relevant payment shall be due upon the immediately preceding Business Day,
except if such payment due date is a Sunday or Monday, then the relevant payment
shall be due upon the immediately succeeding Business Day. Any amounts which
remain due and owing after the due date shall bear interest thereon at the lower
of the United States Treasury 90-Day T-Bill interest rate, as published in the
Wall Street Journal on the first Day such rate is quoted at the beginning of
each calendar quarter, plus thirteen (13%), or the maximum lawful rate of
interest (the "Base Rate"). If a good faith dispute arises as to the amount
payable in any statement, the amount not in dispute shall be paid. if Amoco
elects to withhold any payment otherwise due as a consequence of a good faith
dispute, Amoco shall provide CBF with written notice of its reasons for
withholding payment, and, if the amount of such invoice is equal to or greater
than five thousand dollars ($5,000) or the total aggregate amount of all
invoices in which Amoco has withheld payment and is outstanding at any time is
greater than or equal to twenty five thousand dollars ($25,000), Amoco shall
simultaneously place the disputed amount into an escrow account at a mutually
acceptable commercial bank, pending resolution of the dispute. Amoco's election
to withhold payment from CBF and escrow same as provided herein shall be
exercised within thirty (30) Days from Amoco's

                                       10
<Page>

receipt of the invoice giving rise to such good faith dispute. After the thirty
(30) Day period, Amoco shall be required to pay CBF the full amount of the
invoice whether or not there is a good faith dispute as to the amount payable.
If it is subsequently determined, whether by mutual agreement of the Parties or
otherwise, that (i) Amoco is required to pay all or any portion of the disputed
amounts to CBF or (ii) Amoco is entitled to reimbursement for an invoice it
paid, in addition to paying such amounts, the Party making such payment also
shall pay interest accrued on such amounts at the Base Rate from (1) the
original due date until paid in full, if Amoco is required to pay, or (2) the
date Amoco paid the disputed invoice until paid in full, if CBF is required to
pay.

                            ARTICLE XI: FORCE MAJEURE

11.1 In the event either Party hereto is rendered unable, wholly or in part, by
     reason of Force Majeure to carry out its obligations under this Agreement,
     upon such Party's giving notice and reasonably full particulars of such
     Force Majeure in writing to the other Party after the occurrence of the
     cause relied on, then the obligations of such Party, other than the
     obligation to pay money due hereunder, insofar and only insofar as they are
     affected by such Force Majeure, shall be suspended during the continuance
     of any inability so caused, but for no longer period; and such cause shall,
     so far as reasonably possible, be remedied with all reasonable dispatch.

11.2 The term "Force Majeure" shall mean acts of God, strikes, lockouts or other
     industrial disputes or disturbances, acts of the public enemy, wars,
     blockades, insurrections, riots, epidemics, landslides, lightning,
     earthquakes, fires, tornadoes, hurricanes, storms, and warnings for any of
     the foregoing which may necessitate the precautionary shut-down of wells,
     plants, pipelines, gathering systems, loading facilities, terminals, the
     Fractionator or any portion thereof, or other related facilities, floods,
     washouts, arrests and restraints of governments (either federal, state,
     civil or military), civil disturbances, explosions, sabotage, breakage or
     accidents to equipment, machinery, plants, the Fractionator or any portion
     thereof, or lines of pipe, the lack or failure of brine or brine handling
     capacity, the making of repairs or alterations to any of the foregoing,
     inability to secure labor or materials, freezing of equipment, machinery,
     plants, the Fractionator or any portion thereof, or lines of pipe, partial
     or entire failure of wells or gas supply, electric power shortages,
     necessity for compliance with any court order, or any law, statute,
     ordinance, rule, regulation or order promulgated by a governmental
     authority having or asserting jurisdiction, inclement weather that
     necessitates extraordinary measures and expense to construct facilities
     and/or maintain operations, or any other causes, whether of the kind
     enumerated herein or otherwise, which are not within the control of the
     Party claiming suspension and which by the exercise of due diligence such
     Party is unable to prevent or overcome. Such term shall likewise include,
     in those instances where either Party hereto is required to obtain
     servitudes, rights-of-way, grants, permits or licenses to enable such Party
     to fulfill its obligations hereunder, the inability of such Party to
     acquire, or delays on the part of such Party in acquiring, at reasonable
     cost and after the exercise of reasonable diligence, such servitudes,
     rights-of-way grants, permits or licenses, and in those instances where
     either Party hereto is required to furnish materials and supplies for the
     purpose of

                                       11
<Page>

     constructing or maintaining facilities to enable such Party to fulfill its
     obligations hereunder, the inability of such Party to acquire, or delays on
     the part of such Party in acquiring, at reasonable cost and after the
     exercise of reasonable diligence, such materials and supplies. The term
     "Force Majeure" shall also include any event of force majeure occurring
     with respect to the facilities or services of either Party's suppliers or
     customers providing a service or providing any equipment, goods, supplies
     or other items necessary to the performance of such Party's obligations,
     and shall also include curtailment or interruption of deliveries or
     services by such third-party suppliers or customers as a result of an event
     defined as Force Majeure hereunder.

11.3 Notwithstanding Section 11.1 above, it is understood and agreed that the
     settlement of strikes or lockouts shall be entirely within the discretion
     of the Party having the difficulty, and that the above requirement that any
     Force Majeure shall be remedied with all reasonable dispatch shall not
     require the settlement of strikes or lockouts by acceding to the demands of
     the opposing Party when such course is inadvisable in the discretion of the
     Party having the difficulty.

            ARTICLE XII: INDEMNIFICATION AND LIMITATION OF LIABILITY

12.1. AMOCO'S INDEMNITIES: REGARDLESS OF THE PRESENCE OR ABSENCE OF ANY
     INSURANCE COVERAGE MAINTAINED BY EITHER PARTY HERETO, AMOCO HEREBY
     RELEASES, AND AGREES TO DEFEND, PROTECT, INDEMNIFY AND HOLD HARMLESS, CBF,
     ITS OPERATOR, PARTNERS AND ITS PARTNERS' AFFILIATES AND THOSE ENTITIES'
     RESPECTIVE DIRECTORS, OFFICERS, EMPLOYEES, AGENTS AND REPRESENTATIVES
     ("AMOCO INDEMNIFIED PARTIES") FROM AND AGAINST ANY AND ALL CLAIMS, DEMANDS,
     CAUSES OF ACTION, LIABILITY, LOSS, DAMAGE, PENALTIES, FINES, COST AND
     EXPENSE, INCLUDING COURT COSTS AND ATTORNEY'S FEES IN CONNECTION THEREWITH
     ("CLAIMS"), ARISING OUT OF OR RELATED TO:

     (1)  DESTRUCTION, LOSS OR CONTAMINATION OF AMOCO'S RAW PRODUCT AND
          SPECIFICATION PRODUCTS, EVEN WHERE LIABILITY WITHOUT FAULT WOULD
          OTHERWISE BE IMPOSED ON CBF AND REGARDLESS OF THE CAUSE OF SUCH LOSS,
          INCLUDING, WITHOUT LIMITATION, THE NEGLIGENCE OF ANY OF THE AMOCO
          INDEMNIFIED PARTIES, IT BEING UNDERSTOOD AND AGREED THAT AMOCO SHALL
          RETAIN ALL RISK OF LOSS WITH REGARD TO AMOCO'S RAW PRODUCT AND
          ATTRIBUTABLE SPECIFICATION PRODUCTS, EVEN WHEN SAME IS IN CBF'S
          POSSESSION DURING THE PROVIDING OF SERVICES HEREUNDER; and

     (2)  Except as to Claims within the scope of Sections 12.1.(1) above, any
          Claims arising from injuries or damages to the persons or properties
          arising from damages

                                       12
<Page>

          to the tangible physical property in connection with Amoco's, or its
          contractors, handling and possession of Amoco's Raw Product or
          Specifications Products prior to delivery of same to CBF and after
          delivery of same from CBF back to Amoco or its designated
          representative to the extent of Amoco's or its contractor's negligence
          or legal fault for same.

12.2 CBF INDEMNITIES: Regardless of the presence or absence of any insurance
     coverage maintained by either party hereto, CBF hereby releases, and agrees
     to defend, protect, indemnify and hold harmless, Amoco, and its affiliates,
     and agents and those entities' respective directors, officers, employees,
     agents and representatives ("CBF Indemnified Parties") from and against any
     and all claims, demands, causes of action, liability, loss, damage,
     penalties, fines, cost and expense, including court costs and attorney's
     fees in connection therewith ("Claims"), arising from injuries or damages
     to the persons or properties arising from damages to the tangible physical
     property in connection with CBF's, or its contractors, handling and
     possession of Amoco's Raw Product or Specifications Products while same are
     in CBF's possession and prior to delivery of same to Amoco at the Storage
     Facility to the extent of CBF's or its contractor's negligence or legal
     fault for same.

12.3 LIMITATION OF LIABILITY: NEITHER CBF, CBF'S OPERATOR OR AMOCO SHALL BE
     RESPONSIBLE OR LIABLE TO THE OTHERS, OR TO THEIR AGENTS, FOR ANY SPECIAL,
     INCIDENTAL, CONSEQUENTIAL OR PUNITIVE DAMAGES ARISING OUT OF THIS AGREEMENT
     OR ANY BREACH HEREOF, REGARDLESS OF THE CAUSES OF SAME, INCLUDING WHERE
     CAUSED, BY THE NEGLIGENCE OR FAULT OF THE PARTY WHOSE LIABILITY IS LIMITED
     HEREBY.

                        ARTICLE XIII: DISPUTE RESOLUTION

13.1 COVERED DISPUTES - Any dispute, controversy or claim (whether sounding in
     contract, tort or otherwise) arising out of or relating to this Agreement,
     including, without limitation, the meaning of its provisions, or the proper
     performance of any of its terms by either Party, its breach, termination or
     invalidity ("Dispute") will be resolved in accordance with the procedures
     specified in this Section, which will be the sole and exclusive procedure
     for the resolution of any such Dispute, except that a Party, without
     prejudice to the following procedures, may file a complaint to seek
     preliminary injunctive or other provisional judicial relief, if in its sole
     judgment, that action is necessary to avoid irreparable damage or to
     preserve the status quo. Despite the filing of any such injunctive or other
     provisional judicial relief, the Parties will continue, subject to
     Subsection 13.10 below, to participate in the applicable procedures
     specified in this Section. The obligation to participate in such applicable
     procedures shall not require either Party to participate in the negotiation
     between executives procedures set forth in Subsection 13.3 below or the
     mediation procedures set forth in Subsection 13.4 below if either Party
     determines, in its sole discretion, that such procedures would be futile.

                                       13
<Page>

13.2 INITIATION OF PROCEDURES. Either Party desiring to initiate the dispute
     resolution procedures set forth in this Section with respect to a Dispute
     not resolved in the ordinary course of business (the "Initiating Party")
     must give written notice of the Dispute (the "Dispute Notice") to the other
     Party (the "Non-Initiating Party"). The Dispute Notice shall include (i) a
     statement of that Party's position and a summary of arguments supporting
     that position, and (ii) the name and title of the executive who will
     represent that Party, and of any other person who will accompany the
     executive, in the negotiations under Subsection 13.3 below.

13.3 NEGOTIATION BETWEEN EXECUTIVES - If one Party has given a Dispute Notice
     under Subsection 13.2 above, the Parties may attempt in good faith to
     resolve the Dispute within forty-five (45) Days following receipt of the
     Dispute Notice by the Non-Initiating Party by negotiation between
     executives who have authority to settle the Dispute and who are at a higher
     level of management than the persons with direct responsibility for
     administration of this Agreement or the matter in Dispute. Within fifteen
     (15) Days after receipt of the Dispute Notice, the Non-Initiating Party may
     submit to the other a written response. If given, the response will include
     (i) a statement of that Party's position and a summary of arguments
     supporting that position, and (ii) the name and title of the executive who
     will represent that Party and of any other person who will accompany the
     executive. If such a response is given by the Non-Initiating Party, within
     forty-five (45) Days following receipt of the Dispute Notice by the
     Non-Initiating Party, the executives of both Parties will meet at a
     mutually acceptable time and place, and thereafter, as often as they
     reasonably deem necessary, to attempt to resolve the Dispute.

13.4 MEDIATION - If the Dispute has not been resolved by negotiation under the
     Subsection 13.3 above within forty-five (45) Days following receipt of the
     Dispute Notice by the Non-Initiating Party or if the Non-Initiating Party
     fails to respond within the required fifteen (15) Day period, either Party
     may initiate the mediation procedure of this Subsection by giving written
     notice to the other Party ("Mediation Notice"). The Parties will endeavor
     to settle the Dispute by mediation within sixty (60) Days of the Mediation
     Notice under the then current Center for Public Resources ("CPR") Model
     Mediation Procedure for Business Disputes. If the Parties have not agreed
     upon a mediator within seven (7) Days after the Mediation Notice, either
     Party may request CPR assistance in the selection of a mediator under its
     guidelines. Unless otherwise agreed to by the Parties, no discovery shall
     be allowed during the sixty (60) Day mediation period. If both Parties
     elect to participate in the mediation procedures set forth herein, the cost
     of the mediator will be shared equally between the Parties, unless
     otherwise agreed to in writing by the Parties. If one Party elects not to
     participate in the mediation procedures, neither Party shall bear any cost
     associated with such procedure, other than costs that each Party may have
     incurred in connection therewith which shall be borne by the Party that
     incurred such costs.

13.5 ARBITRATION. If the Dispute has not been resolved by mediation under the
     Subsection 13.4 above within the required sixty (60) Day period or if
     either Party fails and/or refuses to participate in such mediation
     procedures, either Party may request that the matter be resolved through
     arbitration by submitting a written notice (the "Arbitration Notice") to

                                       14
<Page>

     the other. Additionally, if the Parties have been unable to agree on a fee
     re-determination initiated by either Party pursuant to Section 7.3 during
     the Negotiation Period, as set forth in said section, either Party may then
     initiate arbitration to by submitting an Arbitration Notice to the other
     and such fee re-determination shall not be submitted to the procedures set
     forth in Sections 13.2 through 13.4 but shall be arbitrated pursuant to
     this Section 13.5 and the following Subsections 13.6 through 13.10, as
     applicable ("Fee Re-Determination Arbitration"). Any arbitration that is
     conducted hereunder shall be governed by the Federal Arbitration Act, 9
     U.S.C. Section 1 ET SEQ., as amended, and will not be governed by the
     arbitration acts, statutes, or rules of any other jurisdiction.

13.6 ARBITRATION PROCEDURE. The Arbitration Notice shall name the noticing
     Party's arbitrator and shall contain a statement of the issue(s) presented
     for arbitration. Within fifteen (15) Days of receipt of an Arbitration
     Notice, the other Party shall name its arbitrator by written notice to the
     other and may designate any additional issue(s) for arbitration. The two
     named arbitrators shall select the third arbitrator within fifteen (15)
     Days after the date on which the second arbitrator was named. Should the
     two arbitrators fail to agree on the selection of the third arbitrator,
     either Party shall be entitled to request the Senior Judge of the United
     States District Court for the Southern District of Texas to select the
     third arbitrator. Should either Party fail and/or refuse to name its
     arbitrator within the required fifteen (15) Day period, the other Party
     shall be entitled to request the Senior Judge of the United States District
     Court for the Southern District of Texas to select the arbitrator for such
     Party. Notwithstanding the foregoing, in the case of a Fee Re-Determination
     Arbitration, the Parties shall mutually select a single arbitrator within
     thirty (30) Days after receipt of the Arbitration Notice and if they should
     fail to agree on the arbitrator within that time period, either Party shall
     be entitled to request the Senior Judge of the United States District Court
     for the Southern District of Texas to select the arbitrator. The cost of
     the arbitrator shall be shared equally between the Parties. All arbitrators
     shall be qualified by education or experience within the natural gas
     liquids portion of the energy industry to decide the issues presented for
     arbitration. No arbitrator shall be: a current or former director, officer,
     or employee of either Party or its Affiliates; an attorney (or member of a
     law firm) who has rendered legal services to either Party or its Affiliates
     within the preceding three Years; or an owner of any of the common stock of
     either Party, or its Affiliates.

13.7 ARBITRATION HEARING. The three arbitrators or in the case of Fee
     Re-Determination Arbitration, the single arbitrator shall commence the
     arbitration proceedings within twenty-five (25) Days following the
     appointment of the third arbitrator or the single arbitrator, as
     appropriate. The arbitration proceedings shall be held at a mutually
     acceptable site and if the Parties are unable to agree on a site, the
     arbitrators shall select the site. The arbitrators shall have the authority
     to establish rules and procedures governing the arbitration proceedings,
     including, without limitation, rules concerning discovery. Each Party shall
     have the opportunity to present its evidence at the hearing. The
     arbitrators may call for the submission of pre-hearing statements of
     position and legal authority, but no post-hearing briefs shall be
     submitted. The arbitration panel shall not have the authority to award
     incidental, consequential, special, punitive or exemplary

                                       15
<Page>

     damages. In addition, if an issue under consideration is limited to a
     determination of an amount of money owed by one Party to the other, or Fee
     Re-Determination Arbitration, each Party shall submit to the single
     arbitrator a final offer of its proposed resolution of the dispute ("Final
     Offers"). The arbitrator shall be charged to select from the two Final
     Offers the one which the panel finds to be the most reasonable and
     consistent with the terms and conditions of this Agreement, and the
     arbitrator shall not average the Parties' proposals or otherwise craft its
     own remedy. With regard to Fee Re-Determination Arbitration, the basis for
     the arbitrator's decision shall be based on the factors set forth is said
     Section 7.3 All evidence submitted in an arbitration proceeding,
     transcripts of such proceedings, and all documents submitted by the Parties
     in an arbitration proceeding shall be kept confidential and shall not be
     disclosed to any third Party by either Party hereto.

13.8 ARBITRATION DECISION AND COSTS. The decision of the arbitrators or a
     majority of them, shall be in writing and shall be final and binding upon
     the Parties as to the issue(s) submitted. The cost of the hearing shall be
     shared equally by the Parties, and, except as provided in Section 13.6,
     each Party shall be responsible for its own expenses and those of its
     counsel or other representatives. Each Party hereby irrevocably waives, to
     the fullest extent permitted by law, any objection it may have to the
     arbitrability of any such disputes, controversies or claims and further
     agrees that a final determination in any such arbitration proceeding shall
     be conclusive and binding upon each Party.

13.9 ENFORCEMENT OF AWARD. Judgment upon any award rendered by the arbitrators
     may be entered in any court having jurisdiction. The prevailing Party shall
     be entitled to reasonable attorneys' fees in any contested court proceeding
     brought to enforce or collect any award of judgment rendered by the
     arbitrators.

13.10 TOLLING AND PERFORMANCE. Except as otherwise provided in this Article
     XIII, all applicable statutes of limitation and defenses based upon the
     passage of time and all contractual limitation periods specified in this
     Agreement, if any, will be tolled while the procedures specified in this
     Article XIII are pending. The Parties will take all actions to effectuate
     necessary to effectuate the tolling of any applicable statute of limitation
     or contractual limitation periods. All deadlines specified herein may be
     extended by mutual written agreement of the Parties. Each Party is required
     to continue to perform its obligations under this Agreement pending final
     resolution of any Dispute, unless to do so would be impossible or
     impracticable under the circumstances. Notwithstanding the foregoing, the
     statute of limitations of the State of Texas applicable to the commencement
     of a lawsuit will apply to the commencement of an arbitration under this
     Agreement, except that no defenses will be available based upon the passage
     of time during any negotiation or mediation called for by the preceding
     Subsections of this Section.

                           ARTICLE XIV: MISCELLANEOUS

14.1 EXISTING LAWS AND REGULATIONS. This Agreement and the operations hereunder
     shall be subject to the applicable federal and state laws and the
     applicable orders, laws, rules

                                       16
<Page>

     and regulations of any state or federal authority having or asserting
     jurisdiction, but nothing contained herein shall be construed as a waiver
     of any right to question or contest any such order, law, rule or
     regulation. The parties shall be entitled to regard all such laws, rules,
     regulations and orders as valid and may act in accordance therewith until
     such time as the same may be invalidated by final judgment in a court of
     competent jurisdiction.

14.2 GOVERNING LAW. THIS AGREEMENT AND THE RIGHTS AND DUTIES OF THE PARTIES
     ARISING OUT OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED, ENFORCED
     AND PERFORMED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS, AS THE
     SAME MAY BE AMENDED FROM TIME TO TIME, WITHOUT GIVING EFFECT TO ANY CHOICE
     OR CONFLICT OF LAW PROVISION OR RULE THAT WOULD CAUSE THE APPLICATION OF
     THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF TEXAS.

14.3. WAIVER. No waiver by either Party of any default under this Agreement or
     any of the provisions of this Agreement shall be deemed to be a waiver of
     any future default or any other provision hereof, whether of a like or a
     different character. No waiver shall be effective unless made in writing
     and signed by the Party to be charged with such wavier, nor shall such
     waiver constitute a continuing waiver unless expressly provided by the
     Party to be charged with such wavier.

14.4 SUCCESSORS AND ASSIGNS. This Agreement shall inure to the benefit of and be
     binding upon the parties hereto and their respective successors and
     assigns. Notwithstanding the foregoing, neither Party may assign this
     Agreement, nor any interest herein, without the prior written consent of
     the other Party, which consent shall not be unreasonably withheld;
     provided, however, that a Party may from time to time designate an
     Affiliate to perform this Agreement, either in whole or in part, such
     performance being considered that of the Party hereto. It is understood,
     however, that by such designation, said Party hereto does not thereby avoid
     obligations imposed by the terms and provisions hereof. Amoco further
     specifically agrees that it will not assign its interest in the volumes of
     Raw Product dedicated to this Agreement without the prior written consent
     of CBF, which consent shall not be unreasonably withheld; provided such
     assignment is made subject to this Agreement and any Assignee ratifies and
     adopts this Agreement in writing.

14.5 EXHIBITS. Unless specifically otherwise provided, if any term or condition
     expressed or implied in any Exhibit to this Agreement conflicts or is at
     variance with any term or condition of this Agreement, this Agreement shall
     prevail. All Exhibits as referenced herein are attached hereto and made a
     part hereof.

14.6 DTPA WAIVER. THE PARTIES CERTIFY THAT THEY ARE NOT "CONSUMERS" WITHIN THE
     MEANING OF THE TEXAS DECEPTIVE TRADE PRACTICES-CONSUMER PROTECTION ACT,
     SUBCHAPTER E OF CHAPTER 17, SECTIONS 17.42, ET SEQ., OF THE TEXAS BUSINESS
     AND COMMERCE CODE, AS AMENDED ("DTPA"). THE PARTIES COVENANT, FOR
     THEMSELVES AND FOR AND ON BEHALF OF ANY SUCCESSOR OR ASSIGNEE, THAT, IF THE
     DTPA IS APPLICABLE, (a) THE PARTIES ARE "BUSINESS CONSUMERS" AS THAT TERM
     IS DEFINED IN THE DTPA, (b) OTHER THAN SECTION 17.555 OF THE TEXAS BUSINESS
     AND COMMERCE CODE, EACH PARTY HEREBY

                                       17
<Page>

     WAIVES AND RELEASES ALL OF ITS RIGHTS AND REMEDIES UNDER THE DTPA AS
     APPLICABLE TO THE OTHER PARTY AND ITS SUCCESSORS AND ASSIGNS, AND (c) EACH
     PARTY SHALL DEFEND AND INDEMNIFY THE OTHER FROM AND AGAINST ANY AND ALL
     CLAIMS OF OR BY THAT PARTY OR ANY OF ITS SUCCESSOR AND ASSIGNS OR ANY OF
     ITS OR THEIR AFFILIATES BASED IN WHOLE OR IN PARTY OF THE DTPA, ARISING UT
     OF OR IN CONNECTION WITH THE TRANSACTION SET FORTH IN THIS AGREEMENT.

14.7 HEADINGS, ARTICLES AND SECTIONS. All references to Articles" and "Sections"
     herein pertain to Articles and Sections of this Agreement, unless expressly
     stated otherwise. Headings are for purposes of reference only and shall not
     be used to construe the meaning of this Agreement.

14.8 PRINCIPLES OF CONSTRUCTION AND INTERPRETATION. In construing this
     Agreement, the following principles shall be followed:

     (i)    no consideration shall be given to the fact or presumption that
     one Party had a greater or lesser hand in drafting this Agreement:

     (ii)   examples shall not be construed to limit, expressly or by
     implication, the matter they illustrate:

     (iii)  the word "includes" and its syntactical variants mean "includes,
     but is not limited to" and corresponding syntactical variant
     expressions: and

     (iv)   the plural shall be deemed to include the singular and vice
     versa, as applicable.

14.9 NOTICES. Any notice, request, instruction, correspondence, or other
     documentation to be given hereunder by either Party to the other shall be
     in writing and delivered personally or mailed by registered or certified
     mail, postage prepaid and return receipt requested, or facsimile as
     follows:

          FOR CBF:

          To:          Cedar Bayou Fractionators, L.P.
                       c/o Warren Petroleum Company, Limited Partnership
          Attention:   Vice President, Asset Marketing and Services
          At:          1000 Louisiana, Suite 5800
                       Houston, TX 77002-5050

          Phone:       (713) 507-3843
          FAX:         (713) 767-8286

                                       18

<Page>

          With a copy to:   General Counsel
                            Warren Petroleum Company,
                            Limited Partnership
                            1000 Louisiana, Suite 5800
                            Houston, TX 77002-5050
                            Phone: 713-507-6400
                            Fax: 713-507-6987

          FOR AMOCO (EXCEPT ACCOUNTING MATTERS):

          To:          Amoco Oil Company
          Attention:   Manager, NGL Planning and Optimization
                       Mail Code 1102
          At:          200 East Randolph Drive
                       Chicago, Illinois 60601
          or:          P. 0. Box 87707
                       Chicago, Illinois 60681-0707

          Phone:       (312) 856-6730
          FAX:         (312) 616-0624

          FOR AMOCO ACCOUNTING MATTERS:

          To:          Amoco Business Services
          Attention:   NGL Accounting - 14th Floor
          At:          P.O. Box 200, Station M
                       Calgary, Alberta T2P 2H8

          Phone:       (403) 233-1179
          FAX:         (403) 233-1052

      or at such other address as either Party shall designate by written notice
      to the other. A notice sent by facsimile shall be deemed to have been
      receive by the close of the first Business Day following the Day on which
      it was transmitted and confirmed by transmission report or such earlier
      time as confirmed orally or in writing by the receiving Party. Notice by
      U. S. Mail, whether by U. S. Express Mail, registered mail or certified
      mail, or by overnight courier shall be deemed to have been received by the
      close of the second Business Day after the Day upon which its was sent, or
      such earlier time as is confirmed orally or in writing by the receiving
      Party. Any Party may change its address or facsimile number by giving
      notice of such change in accordance with herewith.

14.10 NO THIRD PARTY BENEFICIARY. This Agreement is for the sole benefit of the
      Parties and their respective successors and permitted assigns, and shall
      not inure to the benefit of any other person whomsoever, it being the
      intention of the Parties that no third person shall be deemed a third
      party beneficiary of this Agreement.

                                       19
<Page>

14.11 SEVERABILITY. This Agreement and the operations hereunder shall be subject
      to the valid and applicable federal and state laws and the valid and
      applicable orders, laws, local ordinances, rules, and regulations of any
      local, state or federal authority having jurisdiction, but nothing
      contained herein shall be construed as a waiver of any right to question
      or contest any such order, laws, rules, or regulations in any forum having
      jurisdiction in the premises. If any provision of this Agreement is held
      to be illegal, invalid, or unenforceable under the present or future laws
      effective during the term of this Agreement, (i) such provision will be
      fully severable, (ii) this Agreement will be construed and enforced as if
      such illegal, invalid, or unenforceable provision had never comprised a
      part of this Agreement, and (iii) the remaining provisions of this
      Agreement will remain in full force and effect and will not be affected
      by the illegal, invalid, or unenforceable provision or by its severance
      from this Agreement. Furthermore, in lieu of such illegal, invalid, or
      unenforceable provision, there will be added automatically as a part of
      this Agreement a provision similar in terms to such illegal, invalid, or
      unenforceable provision as may be possible and as may be legal, valid, and
      enforceable. If a provision of this Agreement is or becomes illegal,
      invalid, or unenforceable in any jurisdiction, the foregoing event shall
      not affect the validity or enforceability in that jurisdiction of any
      other provision of this Agreement nor the validity or enforceability in
      other jurisdictions of that or any other provision of this Agreement.

14.12 ENTIRE AGREEMENT AND AMENDMENT. This Agreement, including, without
      limitation, all exhibits hereto, integrates the entire understanding
      between the Parties with respect to the subject matter covered and
      supersedes all prior understandings, drafts, discussions, or statements,
      whether oral or in writing, expressed or implied, dealing with the same
      subject matter. This Agreement may not be amended or modified in any
      manner except by a written document signed by both parties that expressly
      amends this Agreement.

14.13 SETOFFS AND COUNTERCLAIMS. Except as otherwise provided herein, each Party
      reserves to itself all rights, set-offs, counterclaims, and other remedies
      and/or defenses which that Party is or may be entitled to arising from or
      out of this Agreement or as otherwise provided by law.

14.14 NO PARTNERSHIP OR ASSOCIATION. Nothing contained in this Agreement shall
      be construed to create an association, trust, partnership, or joint
      venture or impose a trust or partnership duty, obligation, or liability on
      or with regard to either Party.

14.15 NO COMMISSIONS, FEES OR REBATES. Except as expressly authorized by this
      Agreement, no director, employee or agent of either Party shall give or
      receive any commission, fee, rebate gift or entertainment of significant
      cost or value in connection with this Agreement. Any representative or
      representative(s) authorized by either Party may audit the applicable
      records of the other Party for the purpose of determining whether there
      has been compliance with this Section.

                                       20
<Page>

                   'Confidential Treatment Requested'

  14.16 NO PARTNERSHIP, ASSOCIATION, ETC. Nothing contained in this Agreement
        shall be construed to create an association, trust, partnership, or
        joint venture or impose a trust or partnership duty, obligation, or
        liability on or with regard to either Party.

                         ARTICLE XV: FUEL SUPPLY OPTION

        By giving sixty (60) Days written notice to CBF prior to the beginning
        of any calendar year, Amoco may elect to sell fuel gas to CBF at a
*       price equal to [REDACTED] of the then estimated fuel gas consumption of
        the Fractionator, which estimate shall be established Monthly by CBF in
        its sole discretion. Amoco will be solely responsible for all costs
        associated with arranging for the delivery of such fuel gas to the
        Fractionator.

            IN WITNESS WHEREOF, the parties have executed this Agreement as of
  the Day and Year first above written.

  Cedar Bayou Fractionators, L.P.

  By: Downstream Energy Ventures Co., L.L.C.
  Title: Managing General Partner

  By: /s/ William E. Puckett
     ----------------------------
       William E. Puckett
  Title: Vice President
        -------------------------

  AMOCO OIL COMPANY

  By: /s/ A. B. ANDERSON
     ----------------------------

  Title: MANAGER, NGL SUPPLY & LOGISTICS
        -------------------------

                                       21
<Page>

                                   EXHIBIT "A"
                                       to
                             Fractionation Agreement
                                 by and between
                        Cedar Bayou Fractionators, L. P.
                                       and
                                Amoco Oil Company

                            AMOCO'S DEDICATED PLANTS

<Table>
<Caption>
Plant                                        Location
-----                                        --------
<S>                                          <C>
Anschutz                                     Uinta Co., Wyoming

Denver City Plant                            Yoakum Co., Texas

Echo Springs                                 Carbon Co., Wyoming

Goldsmith Plant                              Ector Co., Texas

Headleee Devonian Plant                      Ector Co., Texas

Ignacio                                      La Plata Co., Colorado

Kutz                                         Rio Arriba, Co., New Mexico

Lybrook                                      Rio Arriba Co., New Mexico

Opal                                         Lincoln Co., Wyoming

Painter                                      Uinta Co., Wyoming

San Juan                                     San Juan Co., New Mexico

Walton Plant                                 Winkler Co., Texas

Wamsutter                                    Carbon Co., Wyoming

Wasson C02 Plant                             Yoakum Co., Texas

West Seminole Plant                          Gaines Co., Texas

Whitney Canyon                               Uinta Co., Wyoming

Willard Plant                                Yoakum Co., Texas
</Table>

                                       22

<Page>

                                    EXHIBIT B
                                 ETHANE-PROPANE
                                  80-20 MIXTURE
                                  SPECIFICATION

Product characteristics with test methods are herein specified for
ethane-propane 80-20 mixtures received by Warren Petroleum Company, Limited
Partnership.

<Table>
<Caption>
                                                                                           TEST METHODS
PRODUCT CHARACTERISTICS                             MINIMUM           MAXIMUM              LATEST REVISION
-----------------------                             -------           -------              ---------------
<S>                                                <C>                <C>                <C>

1.  COMPOSITION                                                                            ASTM E-260
         Percent by Liquid Volume
         Methane (Percent of Ethane)                                  2.0                  GPA 2177
         Ethylene (Percent of Ethane)                                 1.0
         Methane, Ethane & Ethylene                 78.0              82.0
         Propane, Propylene, & Butanes              18.0              22.0                 ASTM D-2163
         Propylene                                                    1.0
         Butanes                                                      0.8

2. CORROSION
         Copper Strip @ 100 DEG. F                                    1-b                  ASTM D-1838
         (Invalid if additive or inhibitor
         is used.)
         Corrosion Additive or Inhibitor,
         PPM by Weight                                                1                    Applicable Industry
                                                                                           Practices

3. TOTAL SULFUR

         PPM by Weight in Liquid                                      120                  ASTM D-3246

4. DRYNESS                                                            No Free Water        Visual

5. CARBON DIOXIDE
         PPM by Weight in Liquid                                      1,000                GPA 2177
</Table>

PRODUCT ACCOUNTING

For accounting purposes, methane and ethylene shall be considered ethane,
propylene and butanes shall be considered propane within the above listed
specification limits.

Any excess of these hydrocarbon Components above the specification limits shall
not be accounted for.

                                       1
<Page>

                                    EXHIBIT B
                              PROPANE SPECIFICATION

Product characteristics with test methods are herein specified for propane
received by Warren Petroleum Company, Limited Partnership. This product meets
the requirement of the GPA HD-5 propane specification.

<Table>
<Caption>
                                                                                           TEST METHODS
PRODUCT CHARACTERISTICS                             MINIMUM           MAXIMUM              LATEST REVISION
-----------------------                             -------           -------              ---------------
<S>                                                 <C>               <C>                  <C>

1.  COMPOSITION                                                                            ASTM E-260
         Percent by Liquid Volume Ethane                              As limited by other
                                                                      Components & vapor
                                                                      pressure.
         Propane                                    90.0              100
         Propylene                                                    5.0                  ASTM D-2163
         Butanes & Heavier                                            2.5

2.  VAPOR PRESSURE
         Psig @ 100 DEG. F                                            208                  ASTM D-1267

3.  CORROSION
         Copper Strip @ 100 DEG. F                                    1-b                  ASTM D-1838
         (Invalid if additive or inhibitor is
         used.)
         Corrosion Additive or Inhibitor, PPM
         by Weight.                                                   1                    Applicable Industry Practices

4.  TOTAL SULFUR
         PPM by Weight in Liquid                                      120                  ASTM D-3246

5.  HYDROGEN SULFIDE
         PPM by Weight in Liquid                                      1                    Field - Length of Stain Tube
         (Lab test required if field test is                                               Lab Chromatography with Flame
         positive.)                                                                        Photometric Detector

6.  CARBONYL SULFIDE
         PPM by Weight in Liquid                                      2                    Field - Length of Stain Tube
         (Field test invalid if C(4) + exceeds 1.0
         LV%) (Lab test required if field test                                             Lab - UOP 212 or UOP 791
         is positive.)                                                                     Lab - Gas Chromatography with
                                                                                           Flame Photometric Detector
7.  NON-VOLATILE RESIDUE
         a) Milliliters @ 100 DEG. F                                  0.05                 ASTM D-2158
         b) Oil Stain                                                 Pass

THE FOLLOWING TESTS ARE OPTIONAL, DEPENDING
  UPON THE PRODUCT SOURCE:

8. DRYNESS
         Freeze Valve, Seconds                                        60 (Note 2)          ASTM D-2713

9.  VOLATILE RESIDUE
         95% Evaporated - Temperature, DEG. F                        -37                  ASTM D-1837

10. AMMONIA
         PPM by Weight in Liquid                                      1                    Field - Length of Stain Tube
                                                                                           Lab - UOP 430

11. FLUORIDES
         PPM by Weight in Liquid as                                   5                    Field - Length of Stain Tube
         Monatomic Fluorine

12. OTHER DELETERIOUS SUBSTANCES (PPM BY
      WEIGHT IN LIQUID)
         Includes but not limited to                                  1                    Gas chromatography with flame
         (Isoprene, Butadiene, Vinyl                                                       ionization or electron capture
         Chloride, glycol, amine, caustic)                                                 detection or other
</Table>

NOTES: (1) The test methods for items 2 and 7 are not necessary if a
       compositional analysis is available which indicates compliance with these
       requirements.
       (2) The addition of methanol in the distribution system should be on a
       spot basis and must not exceed a rate of 5 Gallons per 10,000 Gallons of
       product.

                                       2
<Page>

                                    EXHIBIT B
                           NORMAL BUTANE SPECIFICATION

Product characteristics with test methods are herein specified for normal butane
received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                           TEST METHODS
PRODUCT CHARACTERISTICS                             MINIMUM           MAXIMUM              LATEST REVISION
-----------------------                             -------           -------              ---------------
<S>                                                 <C>               <C>                  <C>

1. COMPOSITION                                                                             ASTM E-260
         Percent by Liquid Volume
         Isobutane and Lighter                                        5.0                  ASTM D-2163
         Butylane (Percent of N. Butane)                              1.0
         N. Butane & Butylene                       95.0              100                  GPA 2165
         Pentanes & Heavier                                           2.0

2. VAPOR PRESSURE
         Psig @ 100 DEG. F                                            50                   ASTM D-1267

3. CORROSION
         Copper Strip @ 100 DEG. F                                    1-b                  ASTM D-1838
         (Invalid if additive or inhibitor is
         used.)
         Corrosion Additive or Inhibitor, PPM
         by Weight                                                    1                    Applicable Industry Practices

4. TOTAL SULFUR
         PPM by Weight in Liquid                                      140                  ASTM D-3246

5. VOLATILE RESIDUE
         95% Evaporated - Temperature, DEG. F                         +36                  ASTM D-1837

6.  DRYNESS                                                           No Free Water        Visual
</Table>

NOTE: The test methods for Items 2 and 5 are not necessary if a compositional
analysis indicates compliance with these requirements.

                                       3
<Page>

                                    EXHIBIT B
                             ISOBUTANE SPECIFICATION

Product characteristics with test methods are herein specified for isobutane
received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                           TEST METHODS
PRODUCT CHARACTERISTICS                             MINIMUM           MAXIMUM              LATEST REVISION
-----------------------                             -------           -------              ---------------
<S>                                                 <C>               <C>                  <C>

1. COMPOSITION                                                                             ASTM E-260
         Percent by Liquid Volume
         Propane, Propylene and Lighter                               3.0                   ASTM D-2163
         Isobutane                                  96.0              100
         Butylene, Normal Butane & Heavier                            4.0

2.       VAPOR PRESSURE
         Psig @ 100 DEG. F                                             62                   ASTM D-1267

3. CORROSION
         Copper Strip @ 100 DEG. F                                    1-b                  ASTM D-1838
         (Invalid if additive or inhibitor is
         used.)
         Corrosion Additive or Inhibitor, PPM
         by Weight                                                    1                    Applicable Industry Practices

4. TOTAL SULFUR
         PPM by Weight in Liquid                                      140                  ASTM D-3246

5. VOLATILE RESIDUE
         95% Evaporated - Temperature DEG. F                          +16                  ASTM D-1837

6. DRYNESS                                                            No Free Water        Visual
</Table>

NOTE: The test methods for Items 2 and 5 are not necessary if an adequate
compositional analysis is available which indicates compliance with these
requirements.

                                       4
<Page>

                                    EXHIBIT B
                         NATURAL GASOLINE SPECIFICATION

Product characteristics with test methods are herein specified for natural
gasoline received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                           TEST METHODS
PRODUCT CHARACTERISTICS                             MINIMUM           MAXIMUM              LATEST REVISION
-----------------------                             -------           -------              ---------------
<S>                                                 <C>               <C>                  <C>

1. COMPOSITION                                                                             ASTM E-260
         Percent by Liquid Volume
         Butanes & Lighter                                            3.0                  GPA 2165
         Pentanes & Heavier                         97                100

2. VAPOR PRESSURE

   Psi @ 100 DEG. F, Reid                                              14                  ASTM D-323

3. CORROSION

         Copper Strip @ 104 DEG. F                                    1-b                  ASTM D-130
         (Invalid if additive or inhibitor is
         used.)
         Corrosion Additive or Inhibitor, PPM
         by Weight.                                                   1                    Applicable Industry Practices

4. DOCTOR TEST                                                        Negative             GPA 1138

5. DRYNESS                                                            No Free Water        Visual

6. COLOR                                            +25               No Color             Field White Cup Method
                                                                                           Lab - ASTM D-156
7. DISTILLATION
         End Point, DEG. F                                            375                  ASTM D-216
</Table>

NOTE: The test methods for Items 2 and 7 are not necessary if an adequate
compositional analysis is available which indicates compliance with these
requirements.

                                       5

<Page>

                             FRACTIONATION AGREEMENT

                                 by and between

                         CEDAR BAYOU FRACTIONATORS, L.P.

                                       and

                            WARREN GAS LIQUIDS, INC..

                            EFFECTIVE JANUARY 1, 1998

<Page>

                                 TABLE OF CONTENTS

<Table>
<Caption>
                                                                                            Page
                                                                                            ----
<S>                                                                                         <C>
 ARTICLE I: DEFINITIONS ......................................................................1

 ARTICLE II: TERM ............................................................................4

 ARTICLE III: WARREN'S PERFORMANCE ...........................................................4

 ARTICLE IV: CBF'S PERFORMANCE ...............................................................5

 ARTICLE V: TRANSFER OF CUSTODY ..............................................................6

 ARTICLE VI: MEASUREMENT .....................................................................7

 ARTICLE VII: COMPENSATION TO CBF ............................................................7

 ARTICLE VIII: TAXES AND OTHER PAYMENTS ......................................................8

 ARTICLE IX: ACCOUNTING AND AUDIT PROCEDURES .................................................9

 ARTICLE X: BILLING AND PAYMENT ..............................................................10

 ARTICLE XI: FORCE MAJEURE ...................................................................10

 ARTICLE XII: INDEMNIFICATION AND LIMITATION OF LIABILITY ....................................12

 ARTICLE XIII: DISPUTE RESOLUTION ............................................................13

 ARTICLE XIV: MISCELLANEOUS ..................................................................16

EXHIBIT "A" -- WARREN'S DEDICATED PLANTS

EXHIBIT "B" -- SPECIFICATION PRODUCTS SPECIFICATIONS
</Table>

<Page>

                             FRACTIONATION AGREEMENT

      THIS AGREEMENT (the "Agreement") is made and entered into as of the 1st
Day of January, 1998, by and between, Cedar Bayou Fractionators, L.P., a
Delaware limited partnership (hereinafter referred to as "CBF"), and Warren
Gas Liquids, Inc., a Delaware corporation (hereinafter referred to as
"Warren"), sometimes also referred to individually as "Party" and
collectively as "Parties."

      WITNESSETH:

      WHEREAS, Warren owns, controls or has rights to certain volumes of
natural gas liquids recovered by various natural gas processing facilities
available for fractionation; and

      WHEREAS, CBF owns a Fractionation Facility, hereinafter defined,
situated in Mont Belvieu, Chambers County, Texas; and

      WHEREAS, Warren has arranged for the transportation and delivery of
such Raw Product, hereinafter defined, and/or Butane-Gasoline Mix,
hereinafter defined, to Mont Belvieu, Texas; and

      WHEREAS, CBF has arranged for the receipt of such Raw Product and/or
Butane-Gasoline Mix from Warren, as well as Raw Product and/or
Butane-Gasoline Mix owned by third parties, at the Delivery Point,
hereinafter defined; and

      WHEREAS, it is the mutual desire of CBF and Warren that CBF receive
Warren's Raw Product at the Delivery Point and redeliver to Warren, or its
designee, Specification Products, hereinafter defined, at the Storage
Facility, hereinafter defined, or at other mutually agreeable locations.

      NOW THEREFORE, in consideration of the premises and the mutual
covenants and agreements herein contained, the parties hereto agree as
follows:

                             ARTICLE I: DEFINITIONS

      When the following terms or expressions are used in this Agreement, they
shall have the meanings defined below:

      "AFFILIATE" shall mean a Person that directly or indirectly through one or
      more intermediates, controls, or is controlled by or is under common
      control with the Person specified. The term "control" (including the terms
      "controlled by" or "under common control with") means the possession,
      directly or indirectly, of the power to direct or cause the direction of
      the management and policies of a Person, whether through ownership, by
      contract, or otherwise. Any Person shall be deemed to be an Affiliate of
      any specified Person if such Person owns 50% or more of the voting
      securities of the

                                        1

<Page>

      specified Person, if the specified Person owns fifty percent (50%) or more
      of the voting securities of the specified Person, if the specified Person
      owns fifty percent (50%) or more of the voting securities of such Person,
      or if fifty percent (50%) or more of the voting securities of the
      specified Person and such Person are under common control.

      "BACK-END MIX" shall mean any mixture of Components which will be
      fractionated by the Fractionation Facility without requiring the use of
      the Fractionator's de-ethanizer.

      "BACK-END FEE" shall have the meaning as ascribed to it in Article VII.

      "BARREL" shall mean 42 Gallons.

      "BASE RATE" shall have the meaning as ascribed to it in Article X.

      "BUSINESS DAY" shall mean a Day on which Federal Reserve member banks in
      New York City are open for business.

      "CLAIMS" shall have the meaning as ascribed to in Section 12.1
      hereinafter.

      "COMPONENT" shall mean the individual hydrocarbon constituents of Raw
      Product, including but not limited to: methane, ethane, propane,
      isobutane, normal butane, isopentane, normal pentane, hexanes and heavier,
      as well as other non-hydrocarbon Components allowed by Pipeline.

      "DAY" OR "DAILY" shall mean a twenty-four (24) hour period commencing 7:00
      a.m. Central Standard or Daylight Savings time, as applicable, and
      extending until 7:00 a.m. Central Standard or Daylight Savings time, as
      applicable, on the following Day.

      "DELIVERY POINT" shall mean the point of interconnection between the
      Pipelines and Storage Facility at which point Warren's Raw Product is
      delivered to CBF through the Storage Facility.

      "FEE RE-DETERMINATION ARBITRATION" shall have the meaning set forth in
      Section 13.5.

      "FINAL OFFERS" shall mean final offers made by the Parties prior to
      submission of a monetary dispute to an arbitrator, in the manner specified
      in Section 13.7.

      "FORCE MAJEURE" shall have the meaning as ascribed to it in Article XI.

      "FRACTIONATION FACILITY" OR "FRACTIONATOR" shall mean the fractionation
      unit owned by CBF situated in the vicinity of Mont Belvieu, Chambers
      County, Texas, which is operated by Warren which fractionation unit is
      used for the purpose of fractionating Raw Product streams into
      Specification Products.

                                       2
<Page>

      "GALLON" shall mean the unit of volume used for the purpose of measurement
      of liquid. One U.S. liquid Gallon contains 231 cubic inches when the
      liquid is at a temperature of 60 degrees Fahrenheit and at the vapor
      pressure of the liquid being measured.

      "MONT BELVIEU AREA" shall mean the geographical area surrounding Mont
      Belvieu, Texas including the following Texas counties:

                Brazoria                           Harris
                Chambers                           Jefferson
                Fort Bend                          Liberty
                Galveston                          Montgomery

      "MONTH" OR "MONTHS" OR "MONTHLY" shall mean the period commencing on the
      first Day of a Month and ending on the first Day of the next succeeding
      Month.

      "PIPELINE(S)" shall mean any pipeline which delivers Warren's Raw Product
      to the Storage Facility. Currently, the four (4) pipelines capable of
      delivering such Raw Product are the Seminole Pipeline, the Chaparral
      Pipeline, the West Texas Pipeline, and Black Lake Pipeline. During 1998,
      CBF desires to connect to the Dean Pipeline which is owned and operated by
      Duke Energy.

      "PRIMARY TERM" shall have the meaning as ascribed to it in Article II.

      "RAW PRODUCT" shall mean that mixture of liquid hydrocarbons delivered by
      Pipelines to the Storage Facility in accordance with the terms of any
      connection agreements or pipeline tariffs in effect from time to time.

      "REDELIVERY POINT" shall mean the Storage Facility owned and operated by
      Warren.

      "SPECIFICATION PRODUCT(S)" shall mean the liquid hydrocarbons meeting the
      specifications provided for in Exhibit "B", attached hereto, fractionated
      from the Raw Product.

      "STORAGE FACILITY" shall mean the underground storage facilities owned and
      operated by Warren at or near Mont Belvieu, Chambers County, Texas,
      including, but not limited to, all storage caverns, related surface and
      subsurface equipment, and loading and unloading terminals.

      "WARREN" shall mean Warren Petroleum Company, Limited Partnership.

      "YEAR" OR "YEARLY" shall mean a period of 365 consecutive Days; provided,
      however that any Year which contains the date of February 29 shall consist
      of 366 consecutive Days.

                                       3
<Page>

      "Y-GRADE" shall mean any Raw Product which will be fractionated by CBF's
      fractionation facility other than Back-End Mixes.

      "Y-GRADE FEE" shall have the meaning as ascribed to it in Article VII.

                                 ARTICLE II: TERM

      This Agreement shall have a primary term commencing on January 1, 1998 and
      ending December 31, 2012 (the "Primary Term") and shall continue in effect
      from Year to Year thereafter; provided that either Party shall have the
      right to terminate this Agreement effective at the end of the Primary
      Term or any Yearly anniversary thereafter by giving the other Party at
      least twelve Months prior written notice.

                           ARTICLE III: WARREN'S PERFORMANCE

3.1   Except as set-forth in Section 3.2, Warren shall deliver or cause to be
      delivered to the Delivery Point for fractionation under the terms of the
      Agreement, the Raw Product which it owns and/or controls and which are
      produced from the dedicated plants listed in Exhibit "A", and which are
      delivered to the Mont Belvieu Area. Such Raw Product shall include both
      Y-Grade and Back-End Mixes. Warren further agrees that for any volumes of
      Y-Grade or Back-end Mixes that Warren may now or in the future have
      available from plants that are not listed in Exhibit "A" and that are
      delivered to the Mont Belvieu Area and that can economically be delivered
      and fractionated at CBF versus alternative opportunities, that Warren will
      offer such volumes to become dedicated to CBF and that if CBF accepts
      same, then such volumes shall become dedicated under the terms of this
      Agreement.

3.2   Any volumes which CBF does not commit to accept under the provisions of
      Article IV of this Agreement shall be excepted from the dedication
      set-forth in Section 3.1 above.

3.3   In addition to the volume commitments set-forth in Sections 3.1 and 3.2,
      Warren shall also deliver or cause to be delivered to the Delivery Point
      the Raw Product which Warren owns or controls from the following
      agreements.

      (1)   All fractionation agreements with Enserch Processing, Inc. dated in
            May or June of 1994.

      (2)   Raw Product Purchase Agreement with Western Gas Resources, Inc.
            effective September 1, 1997.

      (3)   Raw Product Purchase Agreement with Westar Gas Company effective
            January 1, 1997.

                                       4
<Page>

                       'Confidential Treatment Requested'

      (4)   Raw Product Purchase Agreement with KN Gas Gathering, Inc. dated
            December 1, 1987.

3.4   Warren shall direct Pipeline to prepare, during each Month, an allocation
      of ownership of the Pipeline's commingled Raw Product, by Components
      actually delivered to CBF. Warren and CBF are to accept and rely on such
      allocation.

3.5   Prior to the beginning of each Month, CBF will estimate the volumes of
      Specification Products for which disposition instructions will be required
      from Warren. Such estimates will be established by utilizing the actual
      volumes of Raw Product delivered to the Fractionation Facility during the
      most recent Month for which actual volumes are available and adjusting for
      anticipated variances as may be advised by Warren from time to time. As
      set forth in Article IX of this Agreement, Warren and CBF shall exchange
      and reconcile Monthly statements detailing Warren's product movement no
      later than the last Day of each succeeding Month following the Month in
      question.

3.6   Warren is procuring the fractionation services under this Agreement for
      the purpose of fractionating Raw Product and not for the purpose of
      reselling such services and agrees not to so resell said services.

                          ARTICLE IV: CBF'S PERFORMANCE

4.1   CBF shall accept delivery of and provide fractionation for a maximum of
*     [REDACTED] Barrels per Day of Warren's Y-Grade and [REDACTED] Barrels per
      Day of Back-End Mixes as determined on a Monthly average basis. Volumes
      above these amounts will be accepted by CBF for fractionation on a space
      available basis.

4.2   CBF shall also accept delivery of and provide fractionation for all
      volumes delivered by Warren in accordance with Section 3.3 and for all
      volumes delivered by Warren from extensions of the agreements set forth in
      Section 3.3.

4.3   CBF shall deliver Specification Products to Warren or its designee at the
      Storage Facility or at other mutually agreed upon locations. CBF will
      redeliver Specification Products during the same Month in which the Raw
      Product containing such Components is delivered to CBF, so long as
      Pipeline deliveries allow for fractionation of said Raw Product at a rate
      approximating the Daily average Pipeline delivery rate for said Month.

4.4   CBF shall not routinely hold back Specification Products from Warren as a
      minimum inventory requirement. However, CBF shall have the right to
      withhold distribution of Warren's Specification Products, on a CBF
      ownership percentage basis, to the extent that CBF has insufficient
      volumes of Specification Products to meet its obligations to its
      fractionation customers. To determine Warren's ownership percentage in
      CBF, Warren's ownership percentage in both DEVCO and CBF shall be
      considered.

                                       5
<Page>

4.5   The quantity of the five Specification Products due Warren will be as
      follows, based on the Pipelines' reported volumes of each Component which
      have been delivered for Warren's account:

      (1)   EP MIX (80/20): the volume will be equal to (a) 100% of the ethane
            Component plus methane Component up to 1.5 liquid volume percent of
            the ethane Component, (b) plus propane Component equal to 25% of
            the volume in (a) above.

      (2)   PROPANE: the volume will be equal to 100% of the propane Component
            minus the propane use for the EP Mix.

      (3)   ISOBUTANE: the volume will be equal to 100% of the isobutane
            Component.

      (4)   NORMAL BUTANE: the volume will be equal to 100% of the normal butane
            Component.

      (5)   NATURAL GASOLINE: the volume will be equal to 100% of the isopentane
            and heavier Components.

4.5   In the event CBF actually produces purity ethane utilizing its existing
      facilities (as of January 1, 1998), then Warren reserves the right to
      receive a prorated share of its ethane as purity ethane. The maximum
      Monthly volume of purity ethane that Warren may elect to receive would be
      calculated as follows:

      AE = [ AEY / TEY ] x E

      Where:

      AE = Warren's prorated share of purity ethane
      AEY = the ethane Component of Warren's delivered Y-Grade during the
                 calendar Month
      TEY = the total amount of ethane Component in Y-Grade delivered to the
                 Fractionator for fractionation services during the calendar
                 Month
      E = the volume of purity ethane produced by CBF during the calendar Month

                            ARTICLE V: TRANSFER OF CUSTODY

      Warren warrants that it has the right to cause the Raw Product to be
fractionated. Custody of the Raw Product shall transfer to CBF at the Delivery
Points, subject to Warren's right, pursuant to Section 4.2 above, to receive
allocated Gallons of Specification Products at the Storage Facility. Custody of
Specification Products shall be delivered to Warren or its designee. CBF shall
at no time take title to the Raw Product or the resulting Specification Products
while such products are in the custody of CBF.

                                       6
<Page>

                       'Confidential Treatment Requested'

                               ARTICLE VI: MEASUREMENT

6.1   Volumes of Raw Product, shall be measured and calculated in accordance
      with the then-current Pipeline tariff or CBF's Pipeline connection
      agreements. CBF shall furnish Warren with current copies of all Pipeline
      connection agreements and any future modifications to such agreements.

6.2   Volumes of Specification Products delivered by CBF in accordance with
      Article IV, shall be measured and calculated in accordance with CBF's
      standard measurement procedures at Mont Belvieu and shall conform to
      good measurement practices in the industry and the then current API
      Manual of Petroleum Measurement Standards. CBF shall furnish Warren
      with the current copies of all standard measurement procedures for Mont
      Belvieu and any future modifications to such procedures.

                        ARTICLE VII: COMPENSATION TO CBF

7.1   Except at provided in Section 7.4, as full consideration for the
      fractionation services provided hereunder, Warren shall pay to CBF a
      fractionation fee for each Gallon of Y-Grade ("Y-Grade Fee") or Back-End
      Mixes ("Back-End Fee") delivered by, or on behalf of, Warren to CBF each
      Month. Such fees shall be determined on a calendar quarter basis by the
      following formulas:

*     Y-Grade Fee = [REDACTED]

                              and

*     Back-End-Fee = [REDACTED]

      Where:

          FUEL = The fuel cost (in $/MMBtu) equivalent to the Houston Ship
                 Channel Index of INSIDE FERC'S GAS MARKET REPORT, for natural
                 gas (large packages) for the preceding calendar quarter plus
*                [REDACTED] per MMBTU.

          ELEC = The combined average cost of purchased electricity (in
                 CENTS/KWH) at the Fractionator for the preceding calendar
                 quarter.

          CPIU = The combined average Consumer Price Index, as published by the
                 United States Department of Labor, for the preceding calendar
                 quarter.

                                       7
<Page>

                       'Confidential Treatment Requested'

7.2   The above fee formulas shall remain in effect during the first five Years
      of the Primary Term unless CBF implements a significant energy reduction
      project similar to that contemplated by Warren and Warren in December of
      1997. If such project is implemented and significant energy consumption
      efficiencies are realized due to same, then CBF and Warren will mutually
      agree upon a new formula to become effective with the start of the first
      Month that follows the start-up of said project by 60 Days. Such new
      formula should initially reflect the same resulting fees as the above
      formulas, but will utilize new factors as are appropriate to be changed to
      reflect the change in energy consumption patterns at the Fractionator,
      provided that the definition of "FUEL," "ELEC" and "CPIU" above shall not
      change.

7.3   Either Party shall have the right to initiate a renegotiation of either or
      both of the above fees and fee formulas to be effective on any or each of
*     the [REDACTED] (the "Price Change Dates") by giving the other Party at
      least ninety (90) Days and no more than one hundred fifty (150) Days
      notice prior to any of the Price Change Dates. Such negotiations shall
      commence immediately upon the date of receipt of such notice by the other
      Party and continue for at least sixty (60) Days thereafter (the
      "Negotiation Period"). During the Negotiation Period, each Party shall
      submit to the other Party one or more written offers for the new fee or
      fees. If CBF and Warren are unable to agree to the new fee or fees by the
      end of the Negotiation Period, either CBF or Warren shall have the right
      to have the new fee or fees re-determined by initiating Fee
      Re-Determination Arbitration pursuant to Sections 13.5 through 13.10,
      provided that in arbitrating such fee re-determinations, the arbitrator's
      choice shall be based on a determination of which of the Parties' Final
      Offers most closely approximates the then current fair market rate for
      the fractionation and other services provided by CBF hereunder, based on
      a five Year term for volumes and composition of Raw Product similar to
      that then being tendered hereunder by Warren, and with the market area
      for comparison being the Mont Belvieu Area.

7.4   The fractionation fees for all volumes delivered by Warren under
      provisions of Section 3.3 shall be the same as the fractionation fees
      provided for in the agreements set forth in Section 3.3.

                         VIII: TAXES AND OTHER PAYMENTS

      Warren shall be responsible for the payment of any royalties,
overriding royalties, and other payments due or to become due on the Raw
Products or the Specification Products which are subject to this Agreement,
Any tax applicable to the Raw Products or the Specification Products or the
services provided by CBF hereunder, including but not limited to any tax
applicable to stored volumes of Specification Products, shall be borne and
paid by Warren unless such tax is by law imposed upon CBF, in which event,
such tax shall be paid by CBF and charged to Warren and reimbursed by Warren.
Warren shall indemnify and hold CBF and their respective Affiliate's
directors, officers, agents and employees harmless from and against any and
all claims, demands or causes of action of any kind, together with all loss,
damage and expense (including

                                       8
<Page>

court costs and attorney's fees) arising with respect to the payment of any
taxes, royalties, overriding royalties and other payments due or to become due
on the services, Raw Products or Specification Products which are subject to
this Agreement.

                   ARTICLE IX: ACCOUNTING AND AUDIT PROCEDURES

9.1   Warren or its designee shall furnish the following reports to CBF: (i)
      Warren's share of Components in the Raw Product delivered each Month for
      the Month in question by the tenth Day of the next succeeding Month; (ii)
      instructions for delivery of Specification Products for the Month in
      question during the Month in question, as set forth in Section 3.4; and
      (iii) twelve (12) Month forecast of Raw Product projected to be delivered
      under this Agreement, as requested by CBF from time to time.

9.2   CBF shall furnish each Month for the preceding Month, the following
      reports to Warren: (i) volumes of Warren's Specification Products
      attributable to the Raw Product delivered to CBF each Month, in accordance
      with the reconciliation described in Section 3.4; (ii) Specification
      Products volumes delivered to Warren or its designee each Month in
      accordance with the reconciliation described in Section 3.4; and (iii)
      Warren's inventories of Specification Product(s) each Month, in accordance
      with the reconciliation described in Section 3.4. CBF shall furnish
      initial reports of these items by the twentieth Day of the Month
      succeeding the Month and shall fully complete volume and money
      reconciliations as described in Section 9.3 below.

9.3   Volume and money reconciliation shall be prepared by Warren and by CBF on
      a Monthly basis. Warren and CBF shall cooperate to identify and reconcile
      volume balances and amounts owed. As each Party completes each Month's
      reconciliation, a copy of the reconciliation shall be sent to the other
      Party but no later than the last Day of the Month succeeding the Month in
      question.

9.4   All invoices or statements issued by CBF and any volume and money
      reconciliation reports, or balancing reports, during any calendar Year
      shall conclusively be presumed to be true and correct after twenty-four
      (24) Months following the end of any such calendar Year, unless within the
      said twenty-four (24) Month period the other Party takes written exception
      thereto and makes claim on the Party issuing the invoice, statement or
      report for adjustment.

9.5   Warren, upon at least thirty (30) Days prior notice in writing to CBF,
      shall have the right to audit the CBF's records pertaining to performance
      under this Agreement, for any calendar Year within the twenty-four (24)
      Month period following the end of such calendar Year; provided, however,
      the making of an audit shall not extend the time for the taking of written
      exception to and the adjustments provided for in Section 9.4. Warren
      shall make every reasonable effort to conduct an audit in a manner which
      will result in a minimum of inconvenience to CBF. CBF shall bear no
      portion of the Warren's audit cost. An audit shall not be conducted more
      than once each Year. CBF shall reply in writing to an audit report within
      180 Days after receipt of such report. Should Warren and CBF fail or be
      unable to resolve any audit disputes, the matter shall be

                                       9
<Page>

      resolved using the dispute resolution procedures set forth in Article 13
      of this Agreement.

9.6   CBF shall retain all financial and volume records for a minimum of
      forty-eight (48) Months following the end of any calendar Year.

                         ARTICLE X. BILLING AND PAYMENT

      After receiving allocation information from Pipeline each Month, CBF shall
furnish Monthly to Warren an invoice reflecting all applicable fees and charges
due and Warren shall pay to CBF the amounts due no later than (i) ten (10) Days
after Warren's receipt of invoice therefor, if the amount of same is fifty
thousand dollars ($50,000) or more or (ii) fifteen (15) Days after receipt of
invoice therefor, if the amount of same is less than fifty thousand dollars
($50,000). If the Day on which any payment is due is not a Business Day, then
the relevant payment shall be due upon the immediately preceding Business Day,
except if such payment due date is a Sunday or Monday, then the relevant payment
shall be due upon the immediately succeeding Business Day. Any amounts which
remain due and owing after the due date shall bear interest thereon at the lower
of the United States Treasury 90-Day T-Bill interest rate, as published in the
Wall Street Journal on the first Day such rate is quoted at the beginning of
each calendar quarter, plus thirteen (13%), or the maximum lawful rate of
interest (the "Base Rate"). If a good faith dispute arises as to the amount
payable in any statement, the amount not in dispute shall be paid. If Warren
elects to withhold any payment otherwise due as a consequence of a good faith
dispute, Warren shall provide CBF with written notice of its reasons for
withholding payment, and, if the amount of such invoice is equal to or greater
than five thousand dollars ($5,000) or the total aggregate amount of all
invoices in which Warren has withheld payment and is outstanding at any time is
greater than or equal to twenty five thousand dollars ($25,000), Warren shall
simultaneously place the disputed amount into an escrow account at a mutually
acceptable commercial bank, pending resolution of the dispute. Warren's election
to withhold payment from CBF and escrow same as provided herein shall be
exercised within thirty (30) Days from Warren's receipt of the invoice giving
rise to such good faith dispute. After the thirty (30) Day period, Warren shall
be required to pay CBF the full amount of the invoice whether or not there is a
good faith dispute as to the amount payable. If it is subsequently determined,
whether by mutual agreement of the Parties or otherwise, that (i) Warren is
required to pay all or any portion of the disputed amounts to CBF or (ii) Warren
is entitled to reimbursement for an invoice it paid, in addition to paying such
amounts, the Party making such payment also shall pay interest accrued on such
amounts at the Base Rate from (1) the original due date until paid in full, if
Warren is required to pay, or (2) the date Warren paid the disputed invoice
until paid in full, if CBF is required to pay.

                           ARTICLE XI: FORCE MAJEURE

11.1  In the event either Party hereto is rendered unable, wholly or in part, by
      reason of Force Majeure to carry out its obligations under this Agreement,
      upon such Party's giving notice and reasonably full particulars of such
      Force Majeure in writing to the other Party after the occurrence of the
      cause relied on, then the obligations of such Party, other than the

                                       10
<Page>

      obligation to pay money due hereunder, insofar and only insofar as they
      are affected by such Force Majeure, shall be suspended during the
      continuance of any inability so caused, but for no longer period; and such
      cause shall, so far as reasonably possible, be remedied with all
      reasonable dispatch.

11.2  The term "Force Majeure" shall mean acts of God, strikes, lockouts or
      other industrial disputes or disturbances, acts of the public enemy, wars,
      blockades, insurrections, riots, epidemics, landslides, lightning,
      earthquakes, fires, tornadoes, hurricanes, storms, and warnings for any
      of the foregoing which may necessitate the precautionary shut-down of
      wells, plants, pipelines, gathering systems, loading facilities,
      terminals, the Fractionator or any portion thereof, or other related
      facilities, floods, washouts, arrests and restraints of governments
      (either federal, state, civil or military), civil disturbances,
      explosions, sabotage, breakage or accidents to equipment, machinery,
      plants, the Fractionator or any portion thereof, or lines of pipe, the
      lack or failure of brine or brine handling capacity, the making of repairs
      or alterations to any of the foregoing, inability to secure labor or
      materials, freezing of equipment, machinery, plants, the Fractionator or
      any portion thereof, or lines of pipe, partial or entire failure of wells
      or gas supply, electric power shortages, necessity for compliance with any
      court order, or any law, statute, ordinance, rule, regulation or order
      promulgated by a governmental authority having or asserting jurisdiction,
      inclement weather that necessitates extraordinary measures and expense to
      construct facilities and/or maintain operations, or any other causes,
      whether of the kind enumerated herein or otherwise, which are not
      within the control of the Party claiming suspension and which by the
      exercise of due diligence such Party is unable to prevent or overcome.
      Such term shall likewise include, in those instances where either Party
      hereto is required to obtain servitudes, rights-of-way, grants, permits
      or licenses to enable such Party to fulfill its obligations hereunder,
      the inability of such Party to acquire, or delays on the part of such
      Party in acquiring, at reasonable cost and after the exercise of
      reasonable diligence, such servitudes, rights-of-way grants, permits or
      licenses, and in those instances where either Party hereto is required
      to furnish materials and supplies for the purpose of constructing or
      maintaining facilities to enable such Party to fulfill its obligations
      hereunder, the inability of such Party to acquire, or delays on the
      part of such Party in acquiring, at reasonable cost and after the
      exercise of reasonable diligence, such materials and supplies. The term
      "Force Majeure" shall also include any event of force majeure occurring
      with respect to the facilities or services of either Party's suppliers
      or customers providing a service or providing any equipment, goods,
      supplies or other items necessary to the performance of such Party's
      obligations, and shall also include curtailment or interruption of
      deliveries or services by such third-party suppliers or customers as a
      result of an event defined as Force Majeure hereunder.

11.3  Notwithstanding Section 11. 1 above, it is understood and agreed that the
      settlement of strikes or lockouts shall be entirely within the discretion
      of the Party having the difficulty, and that the above requirement that
      any Force Majeure shall be remedied with all reasonable dispatch shall not
      require the settlement of strikes or lockouts by acceding to the demands
      of the opposing Party when such course is inadvisable in the discretion of
      the Party having the difficulty.

                                       11
<Page>

              ARTICLE XII: INDEMNIFICATION AND LIMITATION OF LIABILITY

12.1. WARREN'S INDEMNITIES: REGARDLESS OF THE PRESENCE OR ABSENCE OF ANY
      INSURANCE COVERAGE MAINTAINED BY EITHER PARTY HERETO, WARREN HEREBY
      RELEASES, AND AGREES TO DEFEND, PROTECT, INDEMNIFY AND HOLD HARMLESS, CBF,
      ITS OPERATOR, PARTNERS AND ITS PARTNERS' AFFILIATES AND THOSE ENTITIES'
      RESPECTIVE DIRECTORS, OFFICERS, EMPLOYEES, AGENTS AND REPRESENTATIVES
      ("WARREN INDEMNIFIED PARTIES") FROM AND AGAINST ANY AND ALL CLAIMS,
      DEMANDS, CAUSES OF ACTION, LIABILITY, LOSS, DAMAGE, PENALTIES, FINES, COST
      AND EXPENSE, INCLUDING COURT COSTS AND ATTORNEY'S FEES IN CONNECTION
      THEREWITH ("CLAIMS"), ARISING OUT OF OR RELATED TO:

      (1)   DESTRUCTION, LOSS OR CONTAMINATION OF WARREN'S RAW PRODUCT AND
            SPECIFICATION PRODUCTS, EVEN WHERE LIABILITY WITHOUT FAULT WOULD
            OTHERWISE BE IMPOSED ON CBF AND REGARDLESS OF THE CAUSE OF SUCH
            LOSS, INCLUDING, WITHOUT LIMITATION THE NEGLIGENCE OF ANY OF THE
            WARREN INDEMNIFIED PARTIES, IT BEING UNDERSTOOD AND AGREED THAT
            WARREN SHALL RETAIN ALL RISK OF LOSS WITH REGARD TO WARREN'S RAW
            PRODUCT AND ATTRIBUTABLE SPECIFICATION PRODUCTS, EVEN WHEN SAME IS
            IN CBF`S POSSESSION DURING THE PROVIDING OF SERVICES HEREUNDER; and

      (2)   Except as to Claims within the scope of Sections 12.1.(1) above, any
            Claims arising from injuries or damages to the persons or properties
            arising from damages to the tangible physical property in connection
            with Warren's, or its contractors, handling and possession of
            Warren's Raw Product or Specifications Products prior to delivery of
            same to CBF and after delivery of same from CBF back to Warren or
            its designated representative to the extent of Warren's or its
            contractor's negligence or legal fault for same.

12.2  CBF INDEMNITIES: Regardless of the presence or absence of any insurance
      coverage maintained by either party hereto, CBF hereby releases, and
      agrees to defend, protect, indemnify and hold harmless, Warren, and its
      affiliates, and agents and those entities' respective directors, officers,
      employees, agents and representatives ("CBF Indemnified Parties") from and
      against any and all claims, demands, causes of action, liability, loss,
      damage, penalties, fines, cost and expense, including court costs and
      attorney's fees in connection therewith ("Claims"), arising from injuries
      or damages to the persons or properties arising from damages to the
      tangible physical property in connection with CBF's, or its contractors,
      handling and possession of Warren's Raw Product or Specifications Products
      while same are in CBF's possession and prior to delivery of same to Warren
      at the Storage Facility to the extent of CBF's or its contractor's
      negligence or legal fault for same.

                                       12
<Page>

12.3  LIMITATION OF LIABILITY: NEITHER CBF, CBF'S OPERATOR OR WARREN SHALL BE
      RESPONSIBLE OR LIABLE TO THE OTHERS, OR TO THEIR AGENTS, FOR ANY SPECIAL,
      INCIDENTAL, CONSEQUENTIAL OR PUNITIVE DAMAGES ARISING OUT OF THIS
      AGREEMENT OR ANY BREACH HEREOF, REGARDLESS OF THE CAUSES OF SAME,
      INCLUDING WHERE CAUSED BY THE NEGLIGENCE OR FAULT OF THE PARTY WHOSE
      LIABILITY IS LIMITED HEREBY.

                         ARTICLE XIII: DISPUTE RESOLUTION

13.1  COVERED DISPUTES - Any dispute, controversy or claim (whether sounding in
      contract, tort or otherwise) arising out of or relating to this Agreement,
      including, without limitation, the meaning of its provisions, or the
      proper performance of any of its terms by either Party, its breach,
      termination or invalidity ("Dispute") will be resolved in accordance with
      the procedures specified in this Section, which will be the sole and
      exclusive procedure for the resolution of any such Dispute, except that a
      Party, without prejudice to the following procedures, may file a complaint
      to seek preliminary injunctive or other provisional judicial relief, if in
      its sole judgment, that action is necessary to avoid irreparable damage or
      to preserve the status quo. Despite the filing of any such injunctive or
      other provisional judicial relief, the Parties will continue, subject to
      Subsection 13.10 below, to participate in the applicable procedures
      specified in this Section. The obligation to participate in such
      applicable procedures shall not require either Party to participate in the
      negotiation between executives procedures set forth in Subsection 13.3
      below or the mediation procedures set forth in Subsection 13.4 below if
      either Party determines, in its sole discretion, that such procedures
      would be futile.

13.2  INITIATION OF PROCEDURES. Either Party desiring to initiate the dispute
      resolution procedures set forth in this Section with respect to a Dispute
      not resolved in the ordinary course of business (the "Initiating Party")
      must give written notice of the Dispute (the "Dispute Notice") to the
      other Party (the "Non-Initiating Party"). The Dispute Notice shall include
      (i) a statement of that Party's position and a summary of arguments
      supporting that position, and (ii) the name and title of the executive who
      will represent that Party, and of any other person who will accompany the
      executive, in the negotiations under Subsection 13.3 below.

13.3  NEGOTIATION BETWEEN EXECUTIVES - If one Party has given a Dispute Notice
      under Subsection 13.2 above, the Parties may attempt in good faith to
      resolve the Dispute within forty-five (45) Days following receipt of the
      Dispute Notice by the Non-Initiating Party by negotiation between
      executives who have authority to settle the Dispute and who are at a
      higher level of management than the persons with direct responsibility for
      administration of this Agreement or the matter in Dispute. Within fifteen
      (15) Days after receipt of the Dispute Notice, the Non-Initiating Party
      may submit to the other a written response. If given, the response will
      include (i) a statement of that Party's position and a summary of
      arguments supporting that position, and (ii) the name and title of the
      executive who will represent that Party and of any other person who will
      accompany the executive. If such a response is given by the Non-Initiating
      Party, within forty-five (45) Days following receipt

                                       13
<Page>

      of the Dispute Notice by the Non-Initiating Party, the executives of both
      Parties will meet at a mutually acceptable time and place, and thereafter,
      as often as they reasonably deem necessary, to attempt to resolve the
      Dispute.

13.4  MEDIATION - If the Dispute has not been resolved by negotiation under the
      Subsection 13.3 above within forty-five (45) Days following receipt of the
      Dispute Notice by the Non-Initiating Party or if the Non-Initiating Party
      fails to respond within the required fifteen (15) Day period, either Party
      may initiate the mediation procedure of this Subsection by giving written
      notice to the other Party ("Mediation Notice"). The Parties will endeavor
      to settle the Dispute by mediation within sixty (60) Days of the Mediation
      Notice under the then current Center for Public Resources ("CPR") Model
      Mediation Procedure for Business Disputes. If the Parties have not agreed
      upon a mediator within seven (7) Days after the Mediation Notice, either
      Party may request CPR assistance in the selection of a mediator under its
      guidelines. Unless otherwise agreed to by the Parties, no discovery shall
      be allowed during the sixty (60) Day mediation period. If both Parties
      elect to participate in the mediation procedures set forth herein, the
      cost of the mediator will be shared equally between the Parties, unless
      otherwise agreed to in writing by the Parties. If one Party elects not to
      participate in the mediation procedures, neither Party shall bear any cost
      associated with such procedure, other than costs that each Party may have
      incurred in connection therewith which shall be borne by the Party that
      incurred such costs.

13.5  ARBITRATION. If the Dispute has not been resolved by mediation under the
      Subsection 13.4 above within the required sixty (60) Day period or if
      either Party fails and/or refuses to participate in such mediation
      procedures, either Party may request that the matter be resolved through
      arbitration by submitting a written notice (the "Arbitration Notice") to
      the other. Additionally, if the Parties have been unable to agree on a fee
      re-determination initiated by either Party pursuant to Section 7.3 during
      the Negotiation Period, as set forth in said section, either Party may
      then initiate arbitration to by submitting an Arbitration Notice to the
      other and such fee re-determination shall not be submitted to the
      procedures set forth in Sections 13.2 through 13.4 but shall be arbitrated
      pursuant to this Section 13.5 and the following Subsections 13.6 through
      13.10, as applicable ("Fee Re-Determination Arbitration"). Any arbitration
      that is conducted hereunder shall be governed by the Federal Arbitration
      Act, 9 U.S.C. Section 1 ET SEQ., as amended, and will not be governed by
      the arbitration acts, statutes, or rules of any other jurisdiction.

13.6  ARBITRATION PROCEDURE. The Arbitration Notice shall name the noticing
      Party's arbitrator and shall contain a statement of the issue(s) presented
      for arbitration. Within fifteen (15) Days of receipt of an Arbitration
      Notice, the other Party shall name its arbitrator by written notice to the
      other and may designate any additional issue(s) for arbitration. The two
      named arbitrators shall select the third arbitrator within fifteen (15)
      Days after the date on which the second arbitrator was named. Should the
      two arbitrators fail to agree on the selection of the third arbitrator,
      either Party shall be entitled to request the Senior Judge of the United
      States District Court for the Southern District of Texas to select the
      third arbitrator. Should either Party fail and/or refuse to name its
      arbitrator within the required fifteen (15) Day period, the other Party
      shall be entitled to request the Senior Judge of the United States
      District Court for the Southern District of Texas to select the

                                       14
<Page>

      arbitrator for such Party. Notwithstanding the foregoing, in the case of a
      Fee Re-Determination Arbitration, the Parties shall mutually select a
      single arbitrator within thirty (30) Days after receipt of the Arbitration
      Notice and if they should fail to agree on the arbitrator within that time
      period, either Party shall be entitled to request the Senior Judge of the
      United States District Court for the Southern District of Texas to select
      the arbitrator. The cost of the arbitrator shall be shared equally between
      the Parties. All arbitrators shall be qualified by education or experience
      within the natural gas liquids portion of the energy industry to decide
      the issues presented for arbitration. No arbitrator shall be: a current or
      former director, officer, or employee of either Party or its Affiliates;
      an attorney (or member of a law firm) who has rendered legal services to
      either Party or its Affiliates within the preceding three Years; or an
      owner of any of the common stock of either Party, or its Affiliates.

13.7  ARBITRATION HEARING. The three arbitrators or in the case of
      Fee Re-Determination Arbitration, the single arbitrator shall
      commence the arbitration proceedings within twenty-five (25) Days
      following the appointment of the third arbitrator or the single
      arbitrator, as appropriate. The arbitration proceedings shall be
      held at a mutually acceptable site and if the Parties are unable to
      agree on a site, the arbitrators shall select the site. The
      arbitrators shall have the authority to establish rules and
      procedures governing the arbitration proceedings, including, without
      limitation, rules concerning discovery. Each Party shall have the
      opportunity to present its evidence at the hearing. The arbitrators
      may call for the submission of pre-hearing statements of position
      and legal authority, but no post-hearing briefs shall be submitted.
      The arbitration panel shall not have the authority to award
      incidental, consequential, special, punitive or exemplary damages.
      In addition, if an issue under consideration is limited to a
      determination of an amount of money owed by one Party to the other,
      or Fee Re-Determination Arbitration, each Party shall submit to the
      single arbitrator a final offer of its proposed resolution of the
      dispute ("Final Offers"). The arbitrator shall be charged to select
      from the two Final Offers the one which the panel finds to be the
      most reasonable and consistent with the terms and conditions of this
      Agreement, and the arbitrator shall not average the Parties'
      proposals or otherwise craft its own remedy. With regard to Fee
      Re-Determination Arbitration, the basis for the arbitrator's
      decision shall be based on the factors set forth is said Section 7.3
      All evidence submitted in an arbitration proceeding, transcripts of
      such proceedings, and all documents submitted by the Parties in an
      arbitration proceeding shall be kept confidential and shall not be
      disclosed to any third Party by either Party hereto.

13.8  ARBITRATION DECISION AND COSTS. The decision of the arbitrators or a
      majority of them, shall be in writing and shall be final and binding upon
      the Parties as to the issue(s) submitted. The cost of the hearing shall be
      shared equally by the Parties, and, except as provided in Section 13.6,
      each Party shall be responsible for its own expenses and those of its
      counsel or other representatives. Each Party hereby irrevocably waives, to
      the fullest extent permitted by law, any objection it may have to the
      arbitrability of any such disputes, controversies or claims and further
      agrees that a final determination in any such arbitration proceeding shall
      be conclusive and binding upon each Party.

                                       15
<Page>

13.9  ENFORCEMENT OF AWARD. Judgment upon any award rendered by the arbitrators
      may be entered in any court having jurisdiction. The prevailing Party
      shall be entitled to reasonable attorneys' fees in any contested court
      proceeding brought to enforce or collect any award of judgment rendered by
      the arbitrators.

13.10 TOLLING AND PERFORMANCE. Except as otherwise provided in this Article
      XIII, all applicable statutes of limitation and defenses based upon the
      passage of time and all contractual limitation periods specified in this
      Agreement, if any, will be tolled while the procedures specified in this
      Article XIII are pending. The Parties will take all actions to effectuate
      necessary to effectuate the tolling of any applicable statute of
      limitation or contractual limitation periods. All deadlines specified
      herein may be extended by mutual written agreement of the Parties. Each
      Party is required to continue to perform its obligations under this
      Agreement pending final resolution of any Dispute, unless to do so would
      be impossible or impracticable under the circumstances. Notwithstanding
      the foregoing, the statute of limitations of the State of Texas applicable
      to the commencement of a lawsuit will apply to the commencement of an
      arbitration under this Agreement, except that no defenses will be
      available based upon the passage of time during any negotiation or
      mediation called for by the preceding Subsections of this Section.

                           ARTICLE XIV: MISCELLANEOUS

14.1  EXISTING LAWS AND REGULATIONS. This Agreement and the operations hereunder
      shall be subject to the applicable federal and state laws and the
      applicable orders, laws, rules and regulations of any state or federal
      authority having or asserting jurisdiction, but nothing contained herein
      shall be construed as a waiver of any right to question or contest any
      such order, law, rule or regulation. The parties shall be entitled to
      regard all such laws, rules, regulations and orders as valid and may act
      in accordance therewith until such time as the same may be invalidated by
      final judgment in a court of competent jurisdiction.

14.2  GOVERNING LAW. THIS AGREEMENT AND THE RIGHTS AND DUTIES OF THE PARTIES
      ARISING OUT OF THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED, ENFORCED
      AND PERFORMED IN ACCORDANCE WITH THE LAWS OF THE STATE OF TEXAS, AS THE
      SAME MAY BE AMENDED FROM TIME TO TIME, WITHOUT GIVING EFFECT TO ANY CHOICE
      OR CONFLICT OF LAW PROVISION OR RULE THAT WOULD CAUSE THE APPLICATION OF
      THE LAWS OF ANY JURISDICTION OTHER THAN THE STATE OF TEXAS.

14.3. WAIVER. No waiver by either Party of any default under this Agreement or
      any of the provisions of this Agreement shall be deemed to be a waiver of
      any future default or any other provision hereof, whether of a like or a
      different character. No waiver shall be effective unless made in writing
      and signed by the Party to be charged with such wavier, nor shall such
      waiver constitute a continuing waiver unless expressly provided by the
      Party to be charged with such wavier.

14.4  SUCCESSORS AND ASSIGNS. This Agreement shall inure to the benefit of and
      be binding upon the parties hereto and their respective successors and
      assigns. Notwithstanding the

                                       16
<Page>

      foregoing, neither Party may assign this Agreement, nor any interest
      herein, without the prior written consent of the other Party, which
      consent shall not be unreasonably withheld; provided, however, that a
      Party may from time to time designate an Affiliate to perform this
      Agreement, either in whole or in part, such performance being considered
      that of the Party hereto. It is understood, however, that by such
      designation, said Party hereto does not thereby avoid obligations imposed
      by the terms and provisions hereof. Warren further specifically agrees
      that it will not assign its interest in the volumes of Raw Product
      dedicated to this Agreement without the prior written consent of CBF,
      which consent shall not be unreasonably withheld; provided such assignment
      is made subject to this Agreement and any Assignee ratifies and adopts
      this Agreement in writing.

14.5  EXHIBITS. Unless specifically otherwise provided, if any term or condition
      expressed or implied in any Exhibit to this Agreement conflicts or is at
      variance with any term or condition of this Agreement, this Agreement
      shall prevail. All Exhibits as referenced herein are attached hereto and
      made a part hereof.

14.6  DTPA WAIVER. THE PARTIES CERTIFY THAT THEY ARE NOT "CONSUMERS" WITHIN THE
      MEANING OF THE TEXAS DECEPTIVE TRADE PRACTICES-CONSUMER PROTECTION ACT,
      SUBCHAPTER E OF CHAPTER 17, SECTIONS 17.42, ET SEQ., OF THE TEXAS BUSINESS
      AND COMMERCE CODE, AS AMENDED ("DTPA"). THE PARTIES COVENANT, FOR
      THEMSELVES AND FOR AND ON BEHALF OF ANY SUCCESSOR OR ASSIGNEE, THAT, IF
      THE DTPA IS APPLICABLE, (a) THE PARTIES ARE "BUSINESS CONSUMERS" AS THAT
      TERM IS DEFINED IN THE DTPA, (b) OTHER THAN SECTION 17.555 OF THE TEXAS
      BUSINESS AND COMMERCE CODE, EACH PARTY HEREBY WAIVES AND RELEASES ALL OF
      ITS RIGHTS AND REMEDIES UNDER THE DTPA AS APPLICABLE TO THE OTHER PARTY
      AND ITS SUCCESSORS AND ASSIGNS, AND (c) EACH PARTY SHALL DEFEND AND
      INDEMNIFY THE OTHER FROM AND AGAINST ANY AND ALL CLAIMS OF OR BY THAT
      PARTY OR ANY OF ITS SUCCESSOR AND ASSIGNS OR ANY OF ITS OR THEIR
      AFFILIATES BASED IN WHOLE OR IN PARTY OF THE DTPA, ARISING UT OF OR IN
      CONNECTION WITH THE TRANSACTION SET FORTH IN THIS AGREEMENT.

14.7  HEADINGS, ARTICLES AND SECTIONS. All references to "Articles" and
      "Sections" herein pertain to Articles and Sections of this Agreement,
      unless expressly stated otherwise. Headings are for purposes of reference
      only and shall not be used to construe the meaning of this Agreement.

14.8  PRINCIPLES OF CONSTRUCTION AND INTERPRETATION. In construing this
      Agreement, the following principles shall be followed:

      (i) no consideration shall be given to the fact or presumption that one
      Party had a greater or lesser hand in drafting this Agreement:

      (ii) examples shall not be construed to limit, expressly or by
      implication, the matter they illustrate:

      (iii) the word "includes" and its syntactical variants mean "includes,
      but is not limited

                                       17
<Page>

      to" and corresponding syntactical variant expressions: and

      (iv) the plural shall be deemed to include the singular and vice versa, as
      applicable.

14.9  NOTICES. Any notice, request, instruction, correspondence, or other
      documentation to be given hereunder by either Party to the other shall be
      in writing and delivered personally or mailed by registered or certified
      mail, postage prepaid and return receipt requested, or facsimile as
      follows:

          FOR CBF:

          To:             Cedar Bayou Fractionators, L.P.
                          c/o Warren Petroleum Company, Limited Partnership
          Attention:      Vice President, Asset Marketing and Services
          At:             1000 Louisiana, Suite 5800
                          Houston, TX 77002-5050
          Phone:          (713) 507-3843
          FAX:            (713) 767-8286

          With a copy to:     General Counsel
                              Warren Petroleum Company, Limited Partnership
                              1000 Louisiana, Suite 5800
                              Houston, TX 77002-5050
                              Phone: 713-507-6400
                              Fax: 713-507-6987

          FOR WARREN GAS LIQUIDS, INC.:

          To:             Warren Gas Liquids, Inc.
          Attention:      Vice President, Asset Marketing Services
                          1000 Louisiana, Suite 5800
                          Houston, Texas 77002
          Phone:          (713) 507-3843
          FAX:            (713) 767-8286

      or at such other address as either Party shall designate by written notice
      to the other. A notice sent by facsimile shall be deemed to have been
      receive by the close of the first Business Day following the Day on which
      it was transmitted and confirmed by transmission report or such earlier
      time as confirmed orally or in writing by the receiving Party. Notice by
      U. S. Mail, whether by U. S. Express Mail, registered mail or certified
      mail, or by overnight courier shall be deemed to have been received by the
      close of the second Business Day after the Day upon which its was sent, or
      such earlier time as is confirmed orally or in writing by the receiving
      Party. Any Party may change its address or

                                       18
<Page>

      facsimile number by giving notice of such change in accordance with
      herewith.

14.10 NO THIRD PARTY BENEFICIARY. This Agreement is for the sole benefit of the
      Parties and their respective successors and permitted assigns, and shall
      not inure to the benefit of any other person whomsoever, it being the
      intention of the Parties that no third person shall be deemed a third
      party beneficiary of this Agreement.

14.11 SEVERABILITY. This Agreement and the operations hereunder shall be subject
      to the valid and applicable federal and state laws and the valid and
      applicable orders, laws, local ordinances, rules, and regulations of any
      local, state or federal authority having jurisdiction, but nothing
      contained herein shall be construed as a waiver of any right to question
      or contest any such order, laws, rules, or regulations in any forum having
      jurisdiction in the premises. If any provision of this Agreement is held
      to be illegal, invalid, or unenforceable under the present or future laws
      effective during the term of this Agreement, (i) such provision will be
      fully severable, (ii) this Agreement will be construed and enforced as if
      such illegal, invalid, or unenforceable provision had never comprised a
      part of this Agreement, and (iii) the remaining provisions of this
      Agreement will remain in full force and effect and will not be affected by
      the illegal, invalid, or unenforceable provision or by its severance from
      this Agreement. Furthermore, in lieu of such illegal, invalid, or
      unenforceable provision, there will be added automatically as a part of
      this Agreement a provision similar in terms to such illegal, invalid, or
      unenforceable provision as may be possible and as may be legal, valid, and
      enforceable. If a provision of this Agreement is or becomes illegal,
      invalid, or unenforceable in any jurisdiction, the foregoing event shall
      not affect the validity or enforceability in that jurisdiction of any
      other provision of this Agreement nor the validity or enforceability in
      other jurisdictions of that or any other provision of this Agreement.

14.12 ENTIRE AGREEMENT AND AMENDMENT. This Agreement, including, without
      limitation, all exhibits hereto, integrates the entire understanding
      between the Parties with respect to the subject matter covered and
      supersedes all prior understandings, drafts, discussions, or statements,
      whether oral or in writing, expressed or implied, dealing with the same
      subject matter. This Agreement may not be amended or modified in any
      manner except by a written document signed by both parties that expressly
      amends this Agreement.

14.13 SETOFFS AND COUNTERCLAIMS. Except as otherwise provided herein, each Party
      reserves to itself all rights, set-offs, counterclaims, and other remedies
      and/or defenses which that Party is or may be entitled to arising from or
      out of this Agreement or as otherwise provided by law.

14.14 NO PARTNERSHIP OR ASSOCIATION. Nothing contained in this Agreement shall
      be construed to create an association, trust, partnership, or joint
      venture or impose a trust or partnership duty, obligation, or liability on
      or with regard to either Party.

14.15 NO COMMISSIONS, FEES OR REBATES. Except as expressly authorized by this
      Agreement, no director, employee or agent of either Party shall give
      or receive any commission, fee, rebate gift or entertainment of
      significant cost or value in connection with this Agreement.

                                       19
<Page>

      Any representative or representative(s) authorized by either Party may
      audit the applicable records of the other Party for the purpose of
      determining whether there has been compliance with this Section.

14.16 NO PARTNERSHIP, ASSOCIATION, ETC. Nothing contained in this Agreement
      shall be construed to create an association, trust, partnership, or joint
      venture or impose a trust or partnership duty, obligation, or liability on
      or with regard to either Party.

            IN WITNESS WHEREOF, the parties have executed this Agreement as of
the Day and Year first above written.

CEDAR BAYOU FRACTIONATORS, L.P.

By:______________________________
Title:___________________________

WARREN GAS LIQUIDS, INC.

By:______________________________

Title:___________________________

                                       20
<Page>

                                  EXHIBIT "A"
                                       TO

                             FRACTIONATION AGREEMENT
                                 BY AND BETWEEN
                         CEDAR BAYOU FRACTIONATORS, L.P.

                                       AND

                  WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP

                 WARREN'S DEDICATED PLANTS AND TRUCK INJECTION POINTS

<Table>
<Caption>

PLANTS                                         COUNTY/STATE
------                                         ------------
<S>                                           <C>
Anschutz East                                 Uinta Co., Wyoming
Breckridge                                    Stephens Co., Texas
Bridger Lake                                  Summit Co., Texas
Carter Creek                                  Uinta Co., Wyoming
Eunice                                        Lea Co., New Mexico
Goldsmith                                     Ector Co., Texas
Headlee                                       Ector Co., Texas
Indian Basin                                  Eddy Co., New Mexico
Monohans                                      Ward Co., Texas
Monument                                      Lea Co., New Mexico
Moores Orchard                                Fort Bend Co., Texas
New Hope                                      Franklin Co., Texas
Painter (Amoco)                               Uinta Co., Wyoming
Rangley                                       Rio Blanco Co., Colorado
Sandhills/Pakenham                            Crane Co., Texas
Sandhills                                     Crane Co., Texas
Saunders                                      Lea Co., New Mexico
Shackelford                                   Shackelford Co., Texas
Sherman                                       Hansford Co., Texas
Snyder                                        Scurry Co., Texas
Whitney Canyon                                Uinta Co., Wyoming
Pascagoula Refinery*                           Pascagoula, Mississippi

TRUCK INJECTION POINTS                        COUNTY/STATE
----------------------                        ------------
Abilene                                       Taylor Co., Texas
Bridgeport                                    Wise Co., Texas
Gladewater                                    Gregg Co., Texas

</Table>

*Provided the product is fractionated

                                       21
<Page>

                                            EXHIBIT B
                                          ETHANE-PROPANE
                                          80-20 MIXTURE
                                            SPECIFICATION

Product characteristics with test methods are herein specified for
ethane-propane 80-20 mixtures received by Warren Petroleum Company, Limited
Partnership.

<TABLE>
<CAPTION>
                                                                         TEST METHODS
PRODUCT CHARACTERISTICS                 MINIMUM       MAXIMUM          LATEST REVISION
-----------------------                ---------     ----------        -----------------
<S>                                    <C>           <C>               <C>
1. COMPOSITION                                                            ASTM E-260
       Percent by Liquid Volume
       Methane (Percent of Ethane)                       2.0              GPA 2177
       Ethylene (Percent of Ethane)                      1.0
       Methane, Ethane & Ethylene         78.0           82.0
       Propane, Propylene, & Butanes      18.0           22.0             ASTM D-2163
       Propylene                                         1.0
       Butanes                                           0.8

2. CORROSION
       Copper Strip @ 100 DEG. F                         1-b              ASTM D-1838
       (Invalid if additive or inhibitor
       is used.)
       Corrosion Additive or Inhibitor,
       PPM by Weight                                     1                Applicable Industry
                                                                          Practices
3. TOTAL SULFUR
       PPM by Weight in Liquid                           120              ASTM D-3246

4. DRYNESS                                               No Free Water    Visual

5. CARBON DIOXIDE
       PPM by Weight in Liquid                           1,000            GPA 2177
</TABLE>

PRODUCT ACCOUNTING

For accounting purposes, methane and ethylene shall be considered ethane,
propylene and butanes shall be considered propane within the above listed
specification limits.

Any excess of these hydrocarbon Components above the specification limits
shall not be accounted for.

                                       22
<Page>

                                    EXHIBIT B
                              PROPANE SPECIFICATION

Product characteristics with test methods are herein specified for propane
received by Warren Petroleum Company, Limited Partnership. This product meets
the requirement of the GPA HD-5 propane specification.

<Table>
<Caption>
                                                                                  TEST METHODS
PRODUCT CHARACTERISTICS                 MINIMUM           MAXIMUM                LATEST REVISION
-----------------------                 -------           ---------------------  -------------------
<S>                                     <C>               <C>                    <C>
1.  COMPOSITION                                                                  ASTM E-260
       Percent by Liquid Volume Ethane                    As limited by other
                                                          Components & vapor
                                                          pressure.
       Propane                          90.0              100
       Propylene                                          5.0                    ASTM D-2163
       Butanes & Heavier                                  2.5
2.  VAPOR PRESSURE
       Psig @ 100 DEG. F                                  208                    ASTM D-1267
3.  CORROSION
       Copper Strip @ 100 DEG. F                          1-b                    ASTM D-1838
       (Invalid if additive or inhibitor is
       used.)
       Corrosion Additive or Inhibitor, PPM
       by Weight                                          1                      Applicable Industry Practices
4.  TOTAL SULFUR
       PPM by Weight in Liquid                            120                    ASTM D-3246
5.  HYDROGEN SULFIDE
       PPM by Weight in Liquid                            1                      Field - Length of Stain Tube
       (Lab test required if field test is                                       Lab Chromatography with Flame
       positive.)                                                                Photometric Detector
6.  CARBONYL SULFIDE
        PPM by Weight in Liquid                           2                      Field - Length of Stain Tube
        (Field test invalid if C(4)+ exceeds 1.0
        LV%) (Lab test required if field test                                    Lab - UOP 212 or UOP 791
        is positive.)                                                            Lab - Gas Chromatography with
                                                                                 Flame Photometric Detector
7. NON-VOLATILE RESIDUE
        a) Milliliters @ 100 DEG. F                       0.05                   ASTM D-2158
        b) Oil Stain                                      Pass
THE FOLLOWING TESTS ARE OPTIONAL, DEPENDING UPON THE PRODUCT SOURCE:
8.  DRYNESS
        Freeze Valve, Seconds                             60 (Note 2)            ASTM D-2713
9.  VOLATILE RESIDUE
        95% Evaporated - Temperature, DEG. F              -37                    ASTM D-1837
10. AMMONIA
        PPM by Weight in Liquid                           1                      Field - Length of Stain Tube
                                                                                 Lab - UOP 430
11. FLUORIDES
        PPM by Weight in Liquid as                        5                      Field - Length of Stain Tube
        Monatomic Fluorine
12. OTHER DELETERIOUS SUBSTANCES (PPM BY WEIGHT IN LIQUID)
        Includes but not limited to                       1                      Gas chromatography with flame
        (Isoprene, Butadiene, Vinyl                                              ionizaton or electron capture
         Chloride, glycol, amine, caustic)                                       detection or other
</Table>

NOTES:
-------------------

(1) The test methods for items 2 and 7 are not necessary if a compositional
    analysis is available which indicates compliance with these requirements.
(2) The addition of methanol in the distribution system should be on a spot
    basis and must not exceed a rate of 5 Gallons per 10,000 Gallons of
    product.

                                                23

<Page>

                                    EXHIBIT B
                           NORMAL BUTANE SPECIFICATION

Product characteristics with test methods are herein specified for normal
butane received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                  TEST METHODS
PRODUCT CHARACTERISTICS                MINIMUM            MAXIMUM                LATEST REVISION
-----------------------                -------            -------                ---------------
<S>                                    <C>                <C>                    <C>
1. COMPOSITION                                                                   ASTM E-260
       Percent by Liquid Volume
       Isobutane and Lighter                              5.0                    ASTM D-2163
       Butylene (Percent of N. Butane)                    1.0
       N. Butane & Butylene            95.0               100                    GPA 2165
       Pentanes & Heavier                                 2.0
2. VAPOR PRESSURE
       Psig @ 100 DEG. F                                  50                     ASTM D-1267
3. CORROSION
       Copper Strip @ 100 DEG. F                          1-b                    ASTM D-1838
       (Invalid if additive or inhibitor is
       used.)
       Corrosion Additive or Inhibitor, PPM
       by Weight                                          1                      Applicable Industry Practices
4. TOTAL SULFUR
       PPM by Weight in Liquid                            140                    ASTM D-3246
5. VOLATILE RESIDUE
       95% Evaporated - Temperature, DEG. F               +36                    ASTM D-1837
6. DRYNESS                                                 No Free Water         Visual
</Table>

NOTE:
-------------------

The test methods for Items 2 and 5 are not necessary
if a compositional analysis indicates compliance with these requirements.

                                      24

<Page>

                                  EXHIBIT B
                           ISOBUTANE SPECIFICATION

Product characteristics with test methods are herein specified for isobutane
received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                   TEST METHODS
PRODUCT CHARACTERISTICS                        MINIMUM            MAXIMUM        LATEST REVISION
-----------------------                        -------           ---------      --------------------
<S>                                            <C>               <C>            <C>
1. COMPOSITION                                                                  ASTM E-260
        Percent by Liquid Volume
        Propane, Propylene and Lighter                           3.0            ASTM D-2163
        Isobutane                              96.0              100
        Butylene, Normal Butane & Heavier                        4.0
2. VAPOR PRESSURE
        Psig @ 100 DEG. F                                        62             ASTM D-1267
3. CORROSION
        Copper Strip @ 100 DEG. F                                1-b            ASTM D-1838
        (Invalid if additive or inhibitor is
        used.)
        Corrosion Additive or Inhibitor, PPM
        by Weight                                                1              Applicable Industry Practices
4. TOTAL SULFUR
        PPM by Weight in Liquid                                  140            ASTM D-3246
5. VOLATILE RESIDUE
        95% Evaporated - Temperature DEG. F                     +16             ASTM D-1937
6. DRYNESS                                                       No Free Water  Visual
</Table>
NOTE:
-------------------

The test methods for Items 2 and 5 are not necessary if an adequate
compositional analysis is available which indicates compliance with these
requirements.

                                               25

<Page>

                                  EXHIBIT B
                        NATURAL GASOLINE SPECIFICATION

Product characteristics with test methods are herein specified for natural
gasoline received by Warren Petroleum Company, Limited Partnership.

<Table>
<Caption>
                                                                                  TEST METHODS
PRODUCT CHARACTERISTICS                       MINIMUM    MAXIMUM                 LATEST REVISION
-----------------------                       -------    -------                 ------------------
<S>                                           <C>        <C>                     <C>
1.  COMPOSITION                                                                  ASTM E-260
       Percent by Liquid Volume
       Butanes & Lighter                                 3.0                     GPA 2165
       Pentanes & Heavier                     97         100
2. VAPOR PRESSURE
       Psi @ 100 DEG. F, Reid                            14                      ASTM D-323
3. CORROSION
       Copper Strip @ 104 DEG. F                         1-b                     ASTM D-130
       (Invalid if additive or inhibitor is
       used.)
       Corrosion Additive or Inhibitor, PPM
       by Weight                                          1                      Applicable Industry Practices
4. DOCTOR TEST                                            Negative               GPA 1138
5. DRYNESS                                                No Free Water          Visual
6. COLOR                                      +25         No Color               Field White Cup Method
                                                                                 Lab - ASTM D-156
7. DISTILLATION
       End Point, DEG. F                                  375                    ASTM D-216
</Table>

NOTE:
-------------------

The test methods for Items 2 and 7 are not necessary if an adequate
compositional analysis is available which indicates compliance with these
requirements.

                                               26

<Page>

                                    EXHIBIT F

                            ASSIGNMENT AND CONVEYANCE

                                      FROM

                                    [GRANTOR]

                                       TO

                        [CEDAR BAYOU FRACTIONATORS, L.P.
                     OR DOWNSTREAM ENERGY VENTURESCO., L.L.C.]

      WITNESSETH THAT, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, and with reference to that
certain Limited Partnership Agreement with an Effective Date of January 1,
1998, between Downstream Energy Ventures Co., L.L.C., Warren Petroleum
Company, Limited Partnership, and Amoco MB Fractionation Company (the
"Limited Partnership Agreement"), with the capitalized terms used herein
without definition having the respective meanings ascribed thereto in the
Limited Partnership Agreement), the undersigned Grantor hereby GRANTS,
BARGAINS, SELLS, CONVEYS, ASSIGNS, TRANSFERS AND DELIVERS unto Grantee and
its successors and assigns, forever, subject to those encumbrances listed on
Exhibit A attached hereto, which Exhibit A is hereby incorporated herein by
this reference thereto and made a part hereof for all purposes, an undivided
[    (  %)] interest in the following described assets, properties, rights
and interests (collectively, the "CONVEYED INTEREST"):

      (1)   FRACTIONATION FACILITY. All the equipment, personal property and
            facilities comprising that certain natural gas liquids
            fractionation facility, and other facilities appurtenant thereto
            and necessary for the operation of said fractionation facility,
            all as same are located in the Surface Lease Area (as defined
            immediately above), as such fractionator facility is generally
            described in Part II of Exhibit A (the "FRACTIONATOR"), less and
            except those assets described as "Excluded Assets" in Part IV of
            Exhibit A.

      (2)   RELATED FACILITIES. All those facilities and equipment outside of
            the Surface Lease Area related to the Fractionator and which are
            described in Part III of Exhibit A, and excluding any items not
            expressly described therein (the "RELATED FACILITIES").

      (3)   PERMITS. All environmental and other governmental permits,
            licenses, orders, franchises and related instruments or rights
            necessary to the ownership or operation of any portions of the
            Fractionator as described in Exhibit A, and which, in accordance
            with the applicable law or the terms of such instruments are not
            to

<Page>

            be maintained in the name as the operator of the Fractionator and
            that, by their terms, may be assigned ("PERMITS"), as described in
            Part IV of said Exhibit A.

      (4)   CONTRACTS. All of Warren's and DEVCO's right, title and interest
            in and to those certain contracts and agreements relating solely
            to the Fractionator that, by their terms, may be assigned
            including but not limited to fractionation services agreements,
            gas supply, electrical and other utilities purchase agreements,
            maintenance and services agreements and intellectual property
            licensing and confidentiality agreements, as same are listed in
            Part V of Exhibit A ("CONTRACTS").

      (5)   RECORDS. All files, records and other data in the actual
            possession of Warren or DEVCO, necessary for the Partnership's
            operation of the Fractionator (except to the extent same relate
            to any retained properties still owned by Warren and DEVCO);
            including, but not limited to, all operational records, technical
            records, processing records, measurement, pipeline balancing and
            connection agreements, United States Department of Transportation
            and other governmental agency-required files, contract files,
            copies of accounting files, and copies of computer spreadsheets used
            for accounting and allocations, but excluding tax records and
            accounting records which relate exclusively to accounting periods
            prior to the date of contribution of the Fractionator to the
            Partnership. ("RECORDS").

      (6)   EXCLUDED ASSETS. "FRACTIONATOR FACILITY" is understood to
            expressly exclude: (i) any of the equipment, facilities, or
            assets located within the Surface Lease Area and which are
            described in Part VI of Exhibit A ("SURFACE LEASE AREA EXCLUDED
            ASSETS"); and (ii) any and all assets, facilities or properties
            outside of the Surface Lease Area which are not expressly defined
            above as being Related Facilities; (all of same being
            collectively referred to herein as the "EXCLUDED ASSETS").

(Collectively, the "Assets")

      TO HAVE AND TO HOLD the Conveyed Interest in and to the Assets,
together with such rights, titles, interests, remedies, powers and privileges
appertaining thereto, unto Grantee, its successors and assigns, forever.

      AND from and after the date hereof, at the request of Grantee, Grantor
will, at its expense, execute, acknowledge and deliver or cause to be
executed, acknowledged and delivered, such other or additional instruments of
conveyance or transfer as Grantee may reasonably request in order to more
effectively carry out the intent hereof and to better vest in Grantee the
Conveyed Interest intended to be transferred hereunder, as contemplated by
the Limited Partnership Agreement.

      GRANTOR shall not, and does not hereby, warrant title to the Conveyed
Interest in any manner other than as follows: Grantor does warrant and agree
to defend any claims by third parties claiming title or ownership by,
through or under Grantor, but not otherwise warrants title

                                      2

<Page>

to the Conveyed Interest in the Assets and does grants hereby any and all
interest therein which it currently holds;

      NOTWITHSTANDING any other provision hereof to the contrary, nothing
contained herein shall in any way supersede, modify, replace, amend, change,
rescind, waive, exceed, expand, enlarge or in any way affect any of the
provisions, including without limitation any of the representations,
warranties, covenants, indemnities, limitations, rights or remedies contained
in the Limited Partnership Agreement, and this instrument is intended solely
to effect the transfer of the Conveyed Interest sold and purchased as
contemplated by the Limited Partnership Agreement.

      THIS ASSIGNMENT AND CONVEYANCE shall not constitute an assignment of
any contract, operating license or other permit or agreement which, by its
terms or as a matter of law, is not assignable without the consent of a third
party, unless and until such third party shall have consented to such
assignment.

      IN WITNESS WHEREOF, Grantor has caused this instrument to be duly
executed and delivered by one or more of its officers thereunto duly
authorized, on        , 1997, but same to be effective as of January 1, 1998, at
7:00 a.m., Central Standard Time.

                                      [GRANTOR ENTITY NAME]

                                      By:  -------------------------------

                                      Title: -----------------------------

STATE OF TEXAS              Section
                            Section
COUNTY OF HARRIS            Section

BEFORE ME, the undersigned authority, a Notary Public, on this day personally
appeared             , known to me to be the person and              of
[GRANTOR ENTITY], whose name is subscribed to the foregoing instrument and
acknowledged to me that he/she executed the same as the act of such
corporation for the purposes and consideration therein expressed in the
capacity therein stated.

Given under my hand and seal of office this     day of             , 1997.

-----------------------------
Notary Public in and for
The State of Texas

My Commission Expires:

-----------------------------

                                      3

<Page>

                                    EXHIBIT G

                                       TO

                           LIMITED PARTNERSHIP AGREEMENT

                               DISCLOSURE SCHEDULE

1.    Legal Proceedings: Warren's activity in the fractionation business in
      the Mont Belvieu, Texas, area, including any future activities through
      the Partnership, is subject to certain restrictions pursuant to that
      certain Agreement Containing Consent Order between the Federal Trade
      Commission the Warren's ultimate parent company, NGC Corporation, a
      copy of which has been provided to the Partners and the Partners have
      had an adequate opportunity to review same. As an indirect, majority
      owned, subsidiary of NGC Corporation, the Partnership shall also be
      subject to said Agreement Containing Consent Order.

2.    Intellectual Property Assets:

      o     Merox(R) Process License Agreement between Warren and UOP, dated
            September 6, 1996, concerning the use of the Merox(R) patented
            process in two units in the Fractionation Facility, as well as one
            unit located at another Warren facility

      o     Datastream Software License Agreement for Datastream Systems, Inc.
            proprietary MP2 computerized maintenance management system in use
            at the Fractionation Facility.

      o     ABB Simcon, Inc. "Software Sub-licensing Agreement for Digital
            Software Program Binaries" dated October 1, 1991, as supplemented
            by ABB Simcon, Inc. letter of December 1, 1992, for the licensing
            of various PC-Based and Digital VAX/VMS compatible software
            (applications, operating systems and system utilities) in
            connection with the Fractionation Facility's control systems used
            to operate the Facility's process systems.

      o     Saros Corporation "License Agreement with Premium Maintenance Plan"
            with Chevron Information Technology Company, a division of Chevron
            U.S.A. Inc.; pursuant to which Chevron acquired on behalf of Warren
            licensing rights to certain Saros Corporation document and image
            management software, as more fully described therein.

3.    Environmental Disclosures: Due to the unavailability of commercial
disposal facilities for naturally occurring radioactive materials waste
("NORM"), Warren has had to store and retain certain volumes of NORM on site
and the Facility. These NORM wastes result from the fractionation of Raw
Product received at the Facility. Such NORM waste is predominately Pb 210
NORM waste and concentrates in particulate

<Page>

removed in the Facility's amine treating system filters and in sludge present
in various vessels in the Facility, including sumps which capture water that
is drained from various vessels. No disposal facility is currently available
in the State of Texas for such NORM waste and same will continue to be
generated and stored at the Facility after the Effective Date until cost
effective disposal services can be obtained by the Operator. Such wastes are
currently stored in approximately seventy five 55 gallon drums and various
containers located at the Facility, the exact location of which was disclosed
to Amoco representatives, but which is secured.

<Page>

                                   EXHIBIT H
                                    GUARANTY

      This Guaranty Agreement (the "Guaranty") is made effective January 1,
1998 (the "Effective Date") by Amoco Oil Company, a Maryland Corporation
("Guarantor") in favor of Warren Petroleum Company, Limited Partnership and
its subsidiaries and affiliates ("Beneficiary") in consideration of the
Beneficiary entering into various agreements with Amoco Fractionation Company
and Amoco MBF Company (the "Obligors"), both Delaware corporations, relating
to the Cedar Bayou Fractionators, L.P., a Delaware limited partnership.

      The Beneficiary and Obligors are anticipating entering into the
following agreements with regard to the formation of the Partnership (the
"Partnership Agreements") whereby the Obligors will assume certain
obligations and make certain warranties and indemnities as more fully described
in those agreements (the "Obligations"):

      A.    Limited Partnership Agreement of Cedar Bayou Fractionators, L.P.;

      B.    Limited Liability Company Agreement of Downstream Energy Ventures
            Co., L.L.C.; and

      C.    Operating Agreement between the Partnership and Warren.

The Obligors are wholly-owned subsidiaries of Amoco Oil Holding Company, a
wholly-owned subsidiary of Guarantor. The Beneficiary will be entering into
the Partnership

<Page>

Agreements with the Obligors, and the Guarantor wishes to provide this
Guaranty to the Beneficiary to induce the Beneficiary to enter into those
Partnership Agreements.

      This Guaranty by Guarantor shall remain in full force and effect during
the terms of the Partnership Agreements and any extensions or renewals
thereof and thereafter until Obligors have fully performed all of their
respective obligations under the Partnership Agreements.

      The Guarantor waives notice of acceptance hereof and of all defaults or
disputes with the Obligors, notice of demand, presentment, protest or
non-payment and of the settlement or adjustment of such defaults or disputes
and all benefits of discussion and division. The Guarantor, without affecting
its liability hereunder in any respect, consents to and waives notice of any
and all modifications and changes to the terms and provisions of the
Partnership Agreements or any other changes in the Obligors' Obligations.

      The obligation of the Guarantor as set forth in this Guaranty is a
primary and an unconditional obligation and covers all Obligations of the
Obligors to Beneficiary which arise under the Partnership Agreements and all
costs, expenses and attorneys' fees which Beneficiary may incur in
collecting, or endeavoring to collect, all or any part of the Obligations and
enforcing this Guaranty. Guarantor's obligation shall be enforceable before
or after proceeding against Obligors and shall be effective regardless of the
solvency or insolvency of Obligors at any time, the extension or
modification of the Obligations by operation of law or the subsequent
incorporation, reorganization, merger or consolidation of the Obligors or any
other change in the composition, nature, personnel or location of the
Obligors.

                                       2

<Page>

      In executing this Guaranty, the Guarantor represents and warrants to
Beneficiary that:

      A. The Guarantor is a corporation duly organized and validly existing,
is in good standing and has full power and authority to make and deliver
this Guaranty to and in favor of Beneficiary;

      B. The execution, delivery and performance of the Guaranty by the
Guarantor has been dully authorized by all necessary action of its principals
and does not and will not violate the provisions of, or constitute a default
under, any presently applicable law or its organizational instruments or any
agreement presently binding on it; and

      C. This Guaranty has been executed and delivered by a duly authorized
officer of the Guarantor and constitutes a lawful and binding obligation
legally enforceable against Guarantor in accordance with its terms.

      This Guaranty shall be governed by and construed, enforced and
performed in accordance with the laws of the State of Texas as the same may
be amended from time to time, without regard to any choice or conflict of
law, provision or rule that would cause the application of the laws of any
jurisdiction other than the State of Texas. Beneficiary and Guarantor, by
accepting this Guaranty, each submit to the non-exclusive jurisdiction of the
courts of the State of Texas and to the federal courts located in Houston,
Texas, in connection with this Guaranty, but not otherwise.

      Guarantor and Beneficiary agree that the Alternative Dispute Resolution
procedures set forth in Article 13 of the Limited Partnership Agreement of
Cedar Bayou Fractionators, L.P. shall apply to any and all disputes,
controversies or claims (whether sounding in contract, tort or otherwise)
arising out of or relating to this Guaranty,

                                       3

<Page>

including, without limitation, the meaning of its provisions, or the proper
performance of any of its terms, its breach, termination or invalidity, and
the enforcement of same, as though copied herein in its entirety but with the
substitution of Guarantor in the place of Amoco Fractionation Company and
Amoco MBF Company.

      This Guaranty has been duly executed effective as of the Effective Date.

                                      GUARANTOR:

                                      AMOCO OIL COMPANY

                                      By:_______________________________

                                      Name:_____________________________

                                      Title:____________________________

                                      BENEFICIARY:

                                      WARREN PETROLEUM COMPANY,
                                      LIMITED PARTNERSHIP

                                      By: Warren Petroleum G. P., Inc.
                                          its General Partner

                                      By: ____________________________________

                                      Name: Stephen A. Furbacher

                                      Title: President

                                       4

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