Document:

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                                                         Exhibit 10.21(a)

                                 FIRST AMENDMENT

                                       TO

                          LIMITED PARTNERSHIP AGREEMENT

                                       OF

                         CEDAR BAYOU FRACTIONATORS, L.P.
                        (A Delaware Limited Partnership)

THIS FIRST AMENDMENT to Limited Partnership Agreement is entered into as of,
and is effective, the 23rd day of December 1998 for the purpose of amending
that certain "Limited Partnership Agreement of Cedar Bayou Fractionators,
L.P. ("CBF") between Dynegy Midstream Services, Limited Partnership (formerly
known as Warren Petroleum Company, Limited Partnership) ("Dynegy") and Amoco
MB Fractionation Company ("Amoco") effective January 1, 1998 (the
"Agreement"). Said Agreement provided for the creation of a limited
partnership between the parties, for the purpose of owning certain
partnership interests in and to a Delaware limited partnership to own and
operate a fractionation facility situated in Mont Belvieu, Texas.

WHEREAS, effective the same date as the above effective date of this
Amendment simultaneously with the execution of this First Amendment, Dynegy
and Amoco have executed a certain Letter Agreement with Williams Midstream
Natural Gas Liquids, Inc. ("Williams") regarding "Option to Acquire interest
in Cedar Bayou Fractionators, L.P." wherein Williams was granted an option to
acquire a five percent (5%) limited liability interest in CBF. Additionally,
Dynegy has granted an additional option to Williams to acquire certain
portions of Dynegy's  limited partnership interests in CBF (both of said
options being referred to as the "Options"); and

WHEREAS, Dynegy and Amoco have agreed that certain amendments to the Agreement
would be desirable and are required to accommodate the addition of a third owner
in CBF and to reflect other matters for which Dynegy and Amoco have agreed
amendments are appropriate.

NOW, THEREFORE, Amoco and Dynegy hereby agree to amend the Agreement in the
following manner:

1.  GLOBAL CHANGES. To reflect the change of names of the below listed entities,
    all references to the below terms in the Agreement are amended to the below
    listed references, each as of the date indicated:

      a)  All references to "Warren Petroleum Company, Limited Partnership"
          and the defined term "Warren" applicable to said entity (when
          appearing by itself in the Agreement), are

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          amended to be "Dynegy Midstream Services, Limited Partnership" and
          "Dynegy," respectively, effective June 9, 1998.

      b)  All references to "Warren Petroleum G.P., Inc." are amended to be
          "Dynegy Midstream G.P., Inc." effective June 14, 1998.

2.    SECTION 1, PARTNERSHIP FORMATION, SECTION 1.6, TERM, is amended by
      deleting the reference in the first sentence thereof to "eighty-eight
      percent (88%)" and substituting therefor "eighty-six and nine hundred
      twenty-eight thousandths percent (86.928%)."

3.    SECTION 2, DEFINED TERMS, is amended by adding the following new
      definitions and by amending certain existing definitions as indicated
      below:

      a)  NEW DEFINITIONS:

          "ADDITIONAL LIMITED PARTNER" means a Person other than the Initial
          Limited Partners who has acquired a Percentage Interest in the
          Partnership either from all of the Partners or from another Partner
          in accordance with Section 11 of this Agreement, which Percentage
          Interest, as well as the other Partners after the transfer, will be
          reflected in such Additional Limited Partner's Admission Agreement.

          "ADMISSION AGREEMENT" means the agreement between an Additional
          Limited Partner and the Partnership described in Section 11.5 and
          referenced in Section 3.11.

      b)  AMENDMENTS TO EXISTING DEFINITIONS:

          In the first line of the definition of "EFFECTIVE DATE," delete the
          words "first Section" and replace them with "first paragraph."

          "INITIAL LIMITED PARTNERS" are DEVCO, Dynegy and Amoco, as
          identified in the preamble hereof.

          In the definition of "PERCENTAGE INTERESTS," insert in the third
          line before the word "Partners'" the words "Initial Limited", delete
          the last sentence of the definition and replace it with the
          following: "Any Persons who become Additional Limited Partners
          hereunder after the Effective Date of this Agreement in compliance
          with the provisions of this Agreement governing transfers of
          Partnership interests shall hold such Percentage Interests as are
          designated in the transfer to them and as described in their
          Admission Agreement and the Percentage Interests of the Initial
          Limited Partners or other Partners, as applicable, transferring such
          interest to such an Additional Limited Partner shall be adjusted
          accordingly and shall also be described in said Admission Agreement.

4.    Section 3.6, INCREASE IN AMOCO INTEREST., Delete the date "December 31,
      2002" and replace it with "October 1, 2004."

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5.    Add a new Section 3.11 as follows:

      "3.11  ADDITIONAL LIMITED PARTNERS. Each Additional Limited Partner shall
      make Capital Contributions described in its Admission Agreement. The
      amount of the Additional Limited Partner's Capital Contribution, the time
      for making such contributions, and any change in other Limited Partners'
      Capital Accounts and Percentage Interests that may result, shall be set
      forth in such Admission Agreement."

6.    The following amendments are each agreed to be effective only if and when
      Williams acquires a limited partnership interest in CBF:

      a)  SECTION 8.3, VOTING PROCEDURES, is amended by adding the following
          sentence at the end thereof:

          "Provided that proper notice is given or duly waived by the
          Management Committee representatives for all Partners entitled to
          vote at a meeting, the presence of at least two (2) Management
          Committee members, representing Partners which collectively hold
          more than eighty-six and nine hundred twenty-eight thousandths
          percent (86.928%) of the total Percentage Interests in the
          Partnership, shall be sufficient to constitute a quorum for the
          transaction of business."

      b)  SECTION 8.4, VOTE REQUIRED, is amended by changing the reference
          therein to "eighty-eight percent (88%)" to "eighty-six and nine
          hundred twenty-eight thousandths percent (86.928%).

      c)  SECTION 8.6, MATTERS REQUIRING UNANIMOUS APPROVAL, delete the section
          title and introductory sentence and replace them with the following:

          "MATTERS REQUIRING SUPER-MAJORITY APPROVAL. Approval of the
          following matters by the Management Committee shall require a vote
          of members having authority to vote ninety percent (90%) or more of
          the total Percentage Interests of all Partners entitled to vote:"

      d)  SECTION 8.92, REMOVAL OF MANAGING GENERAL PARTNER, is amended by
          changing the reference therein to "eighty-eight percent (88%)" to
          "eighty-six and nine hundred twenty-eight thousandths percent
          (86.928%)."

Except as amended by this First Amendment all other terms and conditions of the
Agreement effective January 1, 1998, shall remain unchanged and in full force
and effect.

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      IN WITNESS WHEREOF, this First Amendment is entered into and executed as
of the date first written above.

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

/s/  STEPHEN A. FURBACHER
---------------------------------------
Name:  Stephen A. Furbacher
Title: President

AMOCO MB FRACTIONATION COMPANY, as Initial Limited Partner

By:  /s/  A. BOYD ANDERSON
---------------------------------------
Name:  A. Boyd Anderson
Title: President

DOWNSTREAM ENERGY VENTURES CO., L.L.C., as General Partner

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

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                                                           Exhibit 10.22

"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 (*)."

                            MUTUAL SERVICES AGREEMENT

                                 BY AND BETWEEN

                         CEDAR BAYOU FRACTIONATORS, L.P.

                                       AND

                    WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP

                            EFFECTIVE JANUARY 1, 1998

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                            MUTUAL SERVICES AGREEMENT

      This MUTUAL SERVICES AGREEMENT is entered into this 16th day of December
1997, to be effective as of January 1, 1998 (the "Effective Date") by and
between Cedar Bayou Fractionators, L.P., a Delaware Limited Partnership (the
"CBF") and Warren Petroleum Company, Limited Partnership ("Warren").

      WHEREAS, as of the Effective Date, CBF has acquired ownership of a certain
natural gas liquids fractionation facility located in Mont Belvieu, Texas,
formerly owned by Warren and Warren has retained title to the adjacent natural
gas liquids storage facility and terminal;

      WHEREAS, the fractionator and the storage facility, as having formerly
been under common ownership, have shared certain facilities and services and CBF
and Warren wish to establish terms under which they will continue the
coordination of operations between the CBF fractionator and the Warren Storage
facility and terminal in order to efficiently operate same and wish to set forth
herein the terms on which CBF and Warren will each provide certain physical
facilities and services to the other during the term of this Agreement;

      NOW, THEREFORE, CBF and Warren agree as follows:

                         ARTICLE 1. SCOPE & DEFINITIONS

1.1   SCOPE

      The Parties agree that each shall be solely responsible for the operation
of their own respective facilities and all costs, expenses and liabilities
related to same excepting only such services and facilities as each Party has
expressly agreed to provide to the other Party under the terms of this
Agreement.

1.2   DEFINITIONS

      The following terms are defined as stated for this purposes of this
      Agreement:

      "ACTION" shall mean any and all claims (whether in contract, tort or
      indemnity), demands, causes of action, liens, actions, suits, alternative
      dispute resolution proceedings and governmental authority proceedings or
      investigations.

      "APPLICABLE LAWS" shall mean all present and future applicable and valid
      laws, rules, regulations, statutes, guidance documents or requirements
      (including consent decrees and administrative orders), codes, ordinances
      or other requirements of the United States or any regional, state or local
      government entity, including all related amendments and implementing
      regulations, including Environmental and Safety Laws.

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

      "CBF FACILITY" means the CBF owned natural gas liquids fractionation
      facility located in Mont Belvieu, Texas, and all the appurtenant equipment
      and facilities related thereto which have been conveyed as of the
      Effective Date hereto, pursuant to the CBF Limited Partnership Agreement,
      from Warren and DEVCO to CBF.

      "CBF OPERATING AGREEMENT" means that certain Operating Agreement of even
      date herewith executed between CBF in its capacity as owner of the CBF
      Facility and Warren in its capacity as CBF's contract operator of the CBF
      Facility.

      "CBF'S OPERATOR" means the contract operator of the CBF Facility, which is
      initially Warren as of the Effective Date.

      "CBF PREMISES" means that area leased to CBF within which the primary
      portions of the CBF Facility are located as indicated by the Surface Lease
      Boundary on the Plot Plan.

      "CLAIMS" shall mean collectively all Actions and Losses.

      "DAY" OR "DAILY" means the period of 24 consecutive hours commencing at
      7:00 a.m. on a calendar day and ending at 7:00 a.m. Central Standard Time
      or Central Daylight Savings Time, as applicable, on the next succeeding
      calendar day.

      "DEVCO" means Downstream Energy Ventures Company, L.L.C, presently the
      general partner of CBF.

      "EFFECTIVE DATE" means January 1, 1998.

      "ENVIRONMENTAL AND SAFETY LAWS" shall mean all Applicable Laws pertaining
      to human health, safety and/or the environment, waste management, natural
      resources, conservation, wildlife, any activity related to any
      environmental matter, including, without limitation, the Comprehensive
      Environmental Response, Compensation, and Liability Act of 1980, 42 U.S.C.
      Sections 9601 ET SEQ. ("CERCLA"); the Resource Conservation and Recovery
      Act, 42 U.S.C Sections 6901 ET SEQ. ("RCRA"); the Clean Water Act, 33
      U.S.C. Sections 1251 ET SEQ.; the Toxic Substances Control Act, 15 U.S.C.
      Sections 2601 ET SEQ.; the Clean Air Act, 42 U.S.C. Sections 7401 ET SEQ.;
      the Hazardous Liquid Pipeline Safety Act, 49 U.S.C. Sections 60101 ET
      SEQ.; the Occupational Safety and Health Act, 29 U.S.C. Sections 651 ET
      SEQ.; and the Natural Gas Pipeline Safety Act, 49 U.S.C. Sections 60101
      ET SEQ., as amended from time to time.

      "ISOM Unit" means the Warren owned isomerization facilities located
      immediately south of the CBF Facility, in the area indicated as the
      "ISOM" area marked in red on the Plot Plan.

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                       'Confidential Treatment Requested'

      "LOSS" shall mean the sum of all costs, expenses (including court costs
      and reasonable attorneys fees), liabilities (whether environmental,
      financial or otherwise), fines, penalties, losses, interest, damages
      (including personal injury to or death of any person or damages or loss of
      any property), decrees, awards, judgments and settlements, including but
      not limited to the cost of investigation thereof.

      "PARTY" means either the CBF or Warren. "Parties" shall mean both CBF and
      Warren.

      "PLOT PLAN" means the plot plan attached hereto, labeled as Exhibit A
      hereto, and initialed by the Parties for identification purposes, which is
      incorporated herein by reference, and which depicts the location of, and
      some detail regarding, the CBF Facility, the Warren Terminal, the ISOM
      Unit and other related facilities.

      "WARREN FACILITIES" shall mean the Warren Terminal, the ISOM Unit and
      other Warren owned facilities located on the Warren Premises.

      "WARREN TERMINAL" shall mean the Warren owned and operated natural gas
      liquids storage facilities which are equipped to store and receive and
      deliver, via pipelines, rail cars, and tank trucks, mixed streams of
      natural gas liquids and final specification products, which are located
      adjacent to the CBF Facility.

      "WARREN PREMISES" shall mean those areas shown on the Plot Plan that are
      outside of the CBF Premises and other Warren property in the general area
      of the Warren Terminal and the CBF Facility.

                                 ARTICLE 2. TERM

      This Agreement shall commence on January 1, 1998, and continue for a term
* of [REDACTED] years thereafter.

                           ARTICLE 3. SERVICES BY CBF

  3.1   FUEL GAS

      CBF shall provide fuel gas to the Warren Terminal and the ISOM Unit as is
  necessary for operation of same, it being understood that same is being
  provided to CBF by third parties and, therefore, CBF cannot guaranty or be
  liable for any interruptions in fuel gas service. All metering of gas volumes
  shall be done by Warren (said meters being located on the Warren Premises) in
  accordance with accepted industry practices as same are in effect at the
  Warren Terminal from time to time.

  3.2   FLARES

      CBF shall allow Warren to continue the physical piping connection between
  the Warren Terminal and the flares and the flare related equipment located at
  the CBF Facility (including, without limitation, flares, flare tanks, and
  water and product pumps), as marked on the Plot Plant, (the "Flare
  Equipment") but excluding the "ISOM Flare" and the "No. 4 Flare Tank for
  ISOM", as same are marked on the Plot Plan. In

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                       'Confidential Treatment Requested'

  connection with such continued connection to the Flare Equipment, Warren shall
  be authorized to flare natural gas liquids and gas originating from the
  Warren Terminal through such flares as are appropriate for the configuration
  and design of same, subject to any operating procedures established by CBF,
  it being understood that any such operating procedures may not constructively
  or otherwise result in Warren being denied the use of the Flare Equipment in
  connection with operations at the Warren Terminal. Both Parties agree to
  cooperate to prepare and file any and all regulatory reports as necessary to
  allow both Parties to use the Flare Equipment and to properly report any
  discharges resulting from the use of the Flare Equipment which are required
  by law to be reported to regulatory authorities. The Party initiating any
  flaring of natural gas liquids, gas or any other substances through their own
  use of the Flare Equipment shall be solely responsible for any fines,
  penalties or assessments arising as a result of such flaring activity and
  hereby agrees to indemnify the Party against same, including any reasonable
  attorney's fees incurred by the other Party prior to tendering any claim
  hereunder to the indemnifying Party for defense of same. Should either Party
  become aware of any proposed assessment, fine or penalty arising from any
  flaring by the other Party hereunder, it shall advise the other Party as soon
  as feasible and allow such Party to manage resolution of any such matter.

      In consideration for the access and use of the Flare Equipment, Warren
* shall pay to CBF [REDACTED] of CBF's costs incurred in the maintenance of the
  Flare Equipment.

  3.3   EMERGENCY NITROGEN SUPPLY

      CBF shall provide emergency nitrogen back up service through the nitrogen
  pipeline currently connected to the CBF Facility and the Warren Terminal and
  shall maintain a nitrogen supply agreement to maintain nitrogen supply in
  said pipeline. Warren agrees, however, that such nitrogen shall be used only
  in an emergency where Warren's normal operating supply of instrument air
  nitrogen has been interrupted and nitrogen is needed to continue operations
  at the Warren Terminal. There shall be no charge to Warren for the
  availability or use of such emergency nitrogen supply provided same is used
  on an emergency basis consistent with the terms of this section.

  3.4   FRESH WELL WATER SUPPLY

      CBF shall supply to the Warren Terminal a supply of fresh water from its
  well water supply system as is needed by the Warren Terminal for
  miscellaneous uses, but same shall not be used in storage well operations or
  for fire water system supply. There will be no charge to Warren for this
  service or such water. Each Party shall maintain their own portions of the
  well water supply system located on their respective facilities at their own
  cost and expense.

  3.5   DRAINAGE CULVERT ACCESS

      Surface runoff water from the Warren Premises collects and drains to
  Cedar Bayou through a concrete lined drainage culvert which traverses the CBF
  Facility. CBF agrees to continue to maintain same in a reasonably clear and
  functional condition

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substantially the same as the condition it is in as of the Effective Date in
order to allow such drainage to continue.

3.6   FIRE WATER SYSTEM

      The Parties acknowledge that the fire water system, including all
equipment and piping, serving both the CBF Facility and the ISOM Unit (the "Fire
Water System") were designed as one system and are not segregated between those
two facilities. Contemporaneous herewith, CBF has acquired all right, title and
interest formerly held by Warren in the entirety of the Fire Water System,
including all portions located both within the CBF Premises and the Warren
Premises. The Parties agree that CBF shall continue to maintain and operate, at
its sole cost and expense, all portions of the Fire Water System wherever
located.

3.7   SHARED SERVICES

       To the extent possible and agreed to by the Parties on a year to year
basis, the below services provided by third parties at the CBF Facility and
the Warren Premises shall be procured under one agreement for both the CBF
Facility and the Warren Premises. For that reason, during the initial year
hereunder, and year to year thereafter as and when approved by CBF's
Management Committee, CBF's Operator shall contract with the appropriate
third parties to provide the following described services and shall
coordinate the actual provision of such services to both facilities. The
portion of the costs incurred for such third party services shall be
allocated each year between the Parties based on factors approved by CBF's
Management Committee as a part of the process of approving the operating and
maintenance expenses budgets submitted annually by CBF's Operator. Should
Warren cease to be CBF's Operator during the term hereof, any then current
successor operator and Warren shall agree to the allocation of such costs
prior to CBF's Operator submitting the CBF share of such costs to the CBF
Management Committee in its proposed annual budget:

      (a)   Equipment maintenance services: Maintainance, servicing of existing
            equipment owned separately by CBF and Warren, procurement of
            replacement equipment, when needed, upon approval of the Party whose
            equipment is being replaced, with all equipment purchase costs to be
            borne solely by the Party receiving same, for the following types of
            equipment and systems:

            (i)   Telephone/PBX;

            (ii)  Radio equipment;

            (iii) Local Area Network and attached computers, and

            (iv)  Communications equipment.

      (b)   Premises security services, if applicable.

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                      'Confidential Treatment Requested'

                          ARTICLE 4. SERVICES BY WARREN

4.1   ELECTRICAL SUPPLY

      (a)   POWER SUPPLY AND SUBSTATION

      The "Warvue electrical substation" (the name designated by Houston
  Lighting & Power for such electrical substation) and power lines connecting
  same to the CBF Facility and the Warren Premises are owned by Warren. Warren,
  as former owner of the CBF Facility, entered into and maintains an electrical
  power contract with Houston Lighting and Power (hereinafter known as the
  "HL&P Contract"), pursuant to which the CBF Facility and the Warren
  Premises are supplied with electrical power from HL&P delivered to a HL&P
  metering facility at the electrical substation. CBF agrees to reimburse
  Warren for the actual electrical cost attributable to the CBF Facility
  which will be prorated based upon data obtained from Warren owned
  electrical meters which measure separately the electricity directed through
  the substation to both the CBF Facility and the Warren Premises.

      (b)   SUBSTATION MAINTENANCE COSTS

      Warren will also maintain a current maintenance contract with an outside
  maintenance firm for all maintenance costs of the substation. The costs
  will be prorated proportionate to power usage for the prior calendar year.
  Non-routine maintenance work that is identifiable to a specific facility
  will be charged 100% to the respective facility.

      (e)   FUTURE ARRANGEMENTS

      Should Warren and CBF mutually agree to do so in the future, the Parties
  may contract separately with HL&P, or mutually enter into an agreement to
  provide for separate and direct billing by HL&P to each Party, so as to
  require the installation of separate HL&P metering for each of their
  respective facilities. The Parties agree that, in such instance, CBF and
  Warren shall each share equally in the costs of installing additional
  metering facilities at the electrical substation and the Parties shall
  agree at such time as to which added items of metering equipment will be
  owned by which Party.

4.2   TRAINING CENTER

      The Warren owned Training Center building and facilities and equipment
  therein shall be used by both Warren and CBF, with Warren being responsible
* for scheduling use and CBF shall reimburse Warren [REDACTED] of the costs
  incurred in the operation and maintenance of same. Should Warren commence
  operation of the ISOM Unit, the percentage allocation of costs will be
  renegotiated subject to Section 5.1.

4.3   CBF SPECIFICATION PRODUCT METERS

      Warren shall maintain the specification product custody transfer meters
  owned by CBF and located on the Warren Terminal premises in normal operating
  condition in accordance with accepted industry tolerances and standards.
  Additionally, Warren shall perform meter provings on such custody transfer
  meters at intervals established by CBF's

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Operator but no less frequently than required by Warren's standard
measurement procedures. Such meter provings shall be performed in accordance
with Warren's standard measurement procedures, as such measurement procedures
may change from time to time, and shall conform to good measurement practices
in the industry and the then current API Manual of Petroleum Measurement
Standards. Warren shall furnish CBF with a copy of Warren's measurement
procedures by January 1, 1998, and Warren shall furnish CBF with a current
copy each time such procedures are changed during the term of this agreement.
CBF shall have the right to witness all such meter provings.

      CBF shall pay Warren for all costs incurred in providing maintenance on
the referenced meters including, but not limited to, labor time expended in
performing meter provings.

4.4   ACCESS TO BRINE POND

      Warren shall continue to allow CBF access to the Warren Terminal's West
Brine Pond to which the CBF "Flare Tank Pump Out" line discharges, as such
line is marked on the Plot Plan, such access to be solely for the purpose of
continuing to operate said Flare Tank Pump Out line to the extent any
discharges from such line are in compliance with all applicable permits.

4.5   UNTREATED WATER SUPPLY

      Warren shall provide CBF with untreated water supplies sufficient to
properly pressurize and operate the fire water system serving the CBF
Facility. CBF will reimburse all of Warren's costs incurred with respect to
untreated water provided to the fire water system, including amounts paid to
the City of Houston for the volumes of untreated water provided to CBF under
this Section 4.5.

4.6   TRUCK SCALES

      Warren will allow the CBF Operator to use the truck scales located at
the Warren Terminal for the purpose of weighing loads removed by waste
removal contractors removing waste from the CBF Facility.

4.7   ISOM UNIT AIR COMPRESSOR

      As of the Effective Date, Warren, as former owner of the CBF Facility,
had connected a newer model air compressor located in the ISOM Unit, and the
title to which has been retained by Warren, to the instrument air system
serving the CBF Facility. Warren agrees to allow CBF to continue to use the
referenced air compressor to provide instrument air to the CBF Facility's
instrument air system; provided, that:

            (i)   CBF's Operator shall maintain said air compressor in good
                  operating condition, ordinary wear and tear excepted, and
                  shall be responsible for the costs of ordinary consumable
                  supplies, electric costs (calculated based on compressor
                  runtime and horsepower) and replacement parts necessary to so
                  maintain said air compressor, and

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            (ii)  Warren may terminate CBF's use of same on thirty (30) Days
                  notice.

                     ARTICLE 5. OTHER AGREEMENTS & SERVICES

      The Parties acknowledge that prior to the Effective Date both the
Warren Facilities and the CBF Facility were under the common ownership and
operation of Warren and in partitioning the ownership of the CBF Facility
from the remainder of the Warren property owned at Warren Facilities and
adjacent properties, the Parties have attempted to determine all services and
equipment and facilities that were used to support both the Warren Facilities
and the CBF Facility in common and establish herein terms for such continued
common use and support. However, the Parties acknowledge that the nature of
the former common ownership and operation of the Warren Facilities and the
CBF Facility, and the physical integration of such facilities in the past,
could create a need for the Parties to address additional items in the future
to allow the Parties to operate and support their respective facilities.
Therefore, the Parties agree as follows:

5.1   ISOM UNIT USAGE

      The Parties acknowledge that the ISOM Unit owned by Warren cannot
operate except in coordination with, and in connection with, the operation of
the CBF Facility but that the ISOM Unit is not currently operating. Should
Warren determine in the future that it wishes to commence operation of the
ISOM Unit, CBF agrees to negotiate in good faith to establish terms under
which the ISOM Unit can receive products from the CBF Facility and other
sources and process same through the ISOM Unit, including compensation
provisions to recognize the costs incurred and benefits received by the
Parties respectively as a result of such operation of the ISOM Unit and CBF
agrees that it will not unreasonably withhold consent to any request from
Warren to coordinate to allow the operation of the ISOM Unit provided that
CBF is kept whole on any costs it might incur in connection with such
operations.

5.2   OTHER SERVICES

      The Parties will negotiate in good faith to amend this Agreement to
address provisions for access by either Party to the services or facilities
of the other Party which were inadvertently omitted, it being understood that
neither Party may be compelled hereby to provide any services or allow
access to any of its facilities to the other Party by virtue of this Section
if it does not agree to the level of cost reimbursement or compensation
therefor, taking into account the administrative burden of providing and
accounting for same, or if it does not agree to allow physical access by the
other Party hereunder to any of its physical facilities due to safety,
regulatory, environmental or legal factors deemed sufficient by such Party.

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                   ARTICLE 6. LIMITATION ON PARTIES' LIABILITY

6.1   DEFINITIONS

      For the purposes of this Article 5, "Party" will be deemed to include each
Party's respective affiliates, officers, directors, agents, employees, partners,
representatives, successors and assigns.

6.2   MUTUAL INDEMNIFY

      NOTWITHSTANDING ANYTHING IN THIS AGREEMENT TO THE CONTRARY, EACH PARTY
(THE "INDEMNIFYING PARTY" FOR PURPOSES OF THIS SECTION 6.2) SPECIFICALLY
AGREES THAT THE OTHER PARTY HEREUNDER (THE "INDEMNIFIED PARTY" FOR PURPOSES
OF THIS SECTION 6.2) SHALL NOT BE LIABLE FOR, AND RELEASES THE INDEMNIFIED
PARTY FROM AND AGREES TO INDEMNIFY AND HOLD HARMLESS THE INDEMNIFIED PARTY
FROM AND AGAINST ANY AND ALL CLAIMS, WHETHER FINANCIAL OR OTHERWISE, IN ANY
WAY ARISING OUT OF, IN CONNECTION WITH, OR INCIDENT TO THE SERVICES PROVIDED
BY THE INDEMNIFIED PARTY HEREUNDER (INCLUDING CONTRACTS OR AGREEMENTS
NECESSARY TO PROVIDE SUCH SERVICES), INCLUDING, BUT NOT LIMITED TO, (I) ANY
VIOLATION OR ALLEGED VIOLATION OF ALL 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 INDEMNIFIED
PARTY. IN ALL CASES DESCRIBED ABOVE, THE INDEMNIFYING PARTY'S OBLIGATION TO
INDEMNIFY AND HOLD THE INDEMNIFIED PARTY 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 INDEMNIFIED PARTY OR ANY OF ITS
CONTRACTORS, PROVIDED, HOWEVER, THAT THE INDEMNIFYING PARTY SHALL NOT BE
REQUIRED TO RELEASE, INDEMNIFY OR HOLD HARMLESS THE INDEMNIFIED PARTY FROM
ANY CLAIMS AND LOSSES ARISING OUT OF, ATTRIBUTABLE TO, IN CONNECTION WITH OR
INCIDENT TO ANY GROSS NEGLIGENCE, FRAUD OR WILLFUL MISCONDUCT OF THE
INDEMNIFIED PARTY OR ITS CONTRACTORS.

6.3   STANDARD OF CARE IN MAINTENANCE & DISCLAIMER OF WARRANTIES

        In connection with performing maintenance or work on the equipment or
other property of the other Party, the Party performing such maintenance or
work shall use ordinary care and shall maintain same in normal operating
condition, ordinary wear and tear excepted, and shall not be liable for the
costs of replacements parts or replacement equipment, which costs shall be
borne by the owner of the particular equipment or property in question EXCEPT
to the extent otherwise specifically provided in Articles 3 or 4 above. THE
FOREGOING NOTWITHSTANDING, BOTH PARTIES HEREBY DISCLAIM ANY AND ALL
WARRANTIES OR REPRESENTATIONS REGARDING THE SERVICES THEY ARE TO PROVIDE
HEREUNDER, INCLUDING ANY EXPRESS OR IMPLIED WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE CONFORMANCE TO ANY SPECIFICATIONS OR
STANDARDS OTHER THAN THOSE SPECIFICALLY SET FORTH IN THIS AGREEMENT.

                                      -9-
<Page>

                      ARTICLE 7. INVOICING, PAYMENT, AUDITS & TAXES

7.1   CHARGES TO CBF PARTNERSHIP ACCOUNT

      During any time periods when Warren is CBF's Operator, the following
terms apply: Warren, in its capacity as CBF's Operator, shall charge CBF's
Partnership account for all amounts for which CBF is obligated hereunder on a
monthly basis, provided same shall be so charged to the CBF's "Account" as
same is defined in the CBF Operating Agreement and consistent with the
authority granted to the "Operator" under the CBF Operating Agreement. Also
on a monthly basis, Warren shall deposit to the said Account of CBF all
amounts which Warren is obligated to pay to CBF hereunder.

7.2    INVOICES & PAYMENTS

      During any time periods when Warren is not CBF's Operator, this Section
7.2 shall be applicable as follows: All amounts payable by either Party
hereunder shall be invoiced by the Party entitled to same (the "Invoicing
Party") by the 25th Day of the month following the month in which same
accrued and shall be payable by the Party obligated to pay same (the "Paying
Party") within thirty (30) Days of the date of the invoice. 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").

7.3   SPARE PARTS & EQUIPMENT TRANSFERS

      To the extent either Party provides spare parts or replacement equipment
out of its own inventory to repair or replace equipment or facilities owned by
the other Party in connection with providing services within the scope of this
Agreement, the cost of same for invoicing purposes shall be established based on
the terms of Part IV, Exhibit A (Accounting Procedure) attached to the CBF
Operating Agreement.

7.4   ADJUSTMENTS

      All charges made by Warren to the CBF Account, as provided for in
Section 7.1 above, or invoices or statements issued during any calendar year
pursuant to Section 7.2 above, 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 Party to whom
a charge was made takes written exception thereto and makes claim on the
other Party hereto for adjustment. No adjustment favorable to Warren when it
is acting in its capacity as CBF's Operator shall be made unless it is made
within the same prescribed period. The provisions of this Section 7.4 shall
not prevent adjustments resulting from a physical inventory of Controllable
Material in the manner provided for in Exhibit "A", Section V, to the CBF
Operating Agreement.

                                      -10-
<Page>

7.5   AUDITS

      Either Party, in its capacity as a Paying Party, upon at least thirty (30)
Days prior notice in writing to the Invoicing Party, shall have the right to
audit the records of the Invoicing Party regarding the fees, charges and
reimbursements invoiced or otherwise charged to the Paying Party hereunder for
any calendar year within the twenty-four (24) calendar month period following
the end of such calendar year. The Paying Party shall make every reasonable
effort to conduct an audit in a manner which will result in a minimum of
inconvenience to Invoicing Party. The Paying Party shall bear all costs of
conducting the audit of such records. An audit shall not be conducted more than
once each year. The Paying Party must present its report and any exceptions to
the Paying Party in writing hereunder within the above stated 24 month period
and the Invoicing Party shall reply in writing to the Paying Party's audit
report within 180 Days after receipt of such report. Should the Parties fail or
be unable to resolve any audit disputes, the matter shall be resolved using the
dispute resolution procedures set forth in Article 8 of this Agreement.

7.6   TAXES

      All fees, charges and reimbursements set forth in this Agreement are
exclusive of taxes. The Paying Party shall be responsible for all taxes,
levies, and assessments directly related to any amounts payable by it,
excepting taxes based on the net income or gross receipts of the Invoicing
Party. The Paying Party shall, upon receipt of notice from the Invoicing
Party, promptly pay, or if the Invoicing Party has paid any such amounts,
reimburse the Invoicing Party for all such taxes, levies, or assessments.
Each Party agrees to hold the other Party harmless from all claims and
liabilities arising from such Party's failure to report or pay such taxes,
excluding penalties, interest or other liabilities which result from, or
could have been avoided, but for, unreasonable delays by the Party claiming a
right for indemnity hereunder in providing the referenced notice for reasons
within its exclusive control.

                  ARTICLE 8. 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, 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

                                      -11-

<Page>

            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 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

                                      -12-

<Page>

            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.

                                      -13-

<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 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,
            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 8, 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 8 are pending. The Parties will
            take all actions to effectuate necessary to

                                      -14-

<Page>

            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 9. LAWS, REGULATIONS AND FORCE MAJEURE

9.1   LAWS AND REGULATIONS

      This Agreement and all operations hereunder shall be subject to all
Applicable Laws, but nothing contained herein shall be construed as a waiver of
any right to question or contest any Applicable Law in any forum having
jurisdiction over the premises.

9.2   GOVERNING LAW

      THIS AGREEMENT AND THE LEGAL RELATIONS BETWEEN THE PARTIES WITH RESPECT TO
THIS AGREEMENT, SHALL BE PERFORMED, INTERPRETED AND ENFORCED IN ACCORDANCE WITH
LAWS OF THE STATE OF TEXAS WITHOUT REGARD TO RULES CONCERNING CONFLICTS OF LAW
THAT WOULD DIRECT THE APPLICATION OF ANY OTHER LAWS.

9.3   FORCE MAJEURE

      In the event of any Party hereto being rendered unable, wholly or in
part, by force majeure to carry out its obligations under this Agreement,
other than to make payments then or thereafter due hereunder, it is agreed
that on such Party giving notice and full particulars of such force majeure
in writing to the other Party as soon as possible after the occurrence of the
cause relied on, then the obligations of the Party giving such notice, so
far 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 as far as possible be remedied with all reasonable and diligent
dispatch by the Party claiming such in order to put itself in a position to
carry out its obligations under this Agreement. The term "force majeure" as
employed herein shall mean acts of God, strikes, lockouts, or other
industrial disturbances, sabotage, wars, blockades, insurrections, riots,
epidemics, landslides, lightning, earthquakes, fires, storms, storm warnings,
floods, washouts, arrests and restraints of governments and people, civil
disturbances, explosions, breakage or accident to equipment, machinery or
lines of pipe, the necessity for making repairs or alterations to equipment,
machinery or lines of pipe, freezing of wells or lines of pipe, partial or
entire failure of wells, pipes or other portions of the Facility, well
failures or blowouts, cratering

                                      -15-

<Page>

of wells, inability to obtain pipe, materials, equipment, rights-of-way,
permits, or labor, any legislative, governmental or judicial actions which are
resisted in good faith, and any other causes, whether of the kind herein
enumerated or otherwise, not within the control of the Party claiming suspension
and which by the exercise of due diligence such Party could not have prevented.
The term Force Majeure as employed herein shall likewise include (a) in those
instances where either Party hereto is required to obtain servitudes,
rights-of-way grants, permits or licenses or any other authority to enable such
Party to acquire, or the 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 or other authority, and (b) in those
instances where either Party hereto is required to furnish materials and
supplies for the purpose of constructing or maintaining the Facility, or is
required to secure permits, licenses, or permissions from any governmental
agency or other authority to enable such Party to fulfill its obligations
hereunder, the inability of such Party to acquire, or the delays on the part of
such Party in acquiring, at reasonable cost and after the exercise of reasonable
diligence, such materials and supplies, permits, permissions and other
authority.

      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 opposing Party when such course is inadvisable in the
discretion of the Party having the difficulty.

                              ARTICLE 10. NOTICES.

10.1  ADDRESSES FOR NOTICES

      Any notice or other communication provided for in this Agreement 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:

      If to CBF:

      CEDAR BAYOU FRACTIONATORS, L.P.
      1000 Louisiana, Suite 5800
      Houston, Texas 77002
      Attention: Vice President, Asset Marketing and Services
      Phone: (713) 507-3843
      Facsimile: (713) 767-8286

                                      -16-

<Page>

      With a copy to:

      AMOCO MB FRACTIONATION COMPANY
      200 East Randolph Drive
      Chicago, Illinois 60601
      Attention:  Manager, NGL Planning and Optimization
      Phone:      (312) 856-6730
      Facsimile:  (312) 616-0624

      If to Warren:

      WARREN PETROLEUM COMPANY, LIMITED PARTNERSHIP
      1000 Louisiana, Suite 5800
      Houston, Texas 77002
      Attention: Vice President, Asset Marketing and Services
      Phone: (713) 507-3843
      Facsimile: (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
      received 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 it was sent, or
      such earlier time as is confirmed orally or in writing by the receiving
      Party. Either Party may change its address or facsimile number by giving
      notice of such change in accordance with herewith.

                          ARTICLE 11. MISCELLANEOUS

      11.1 WAIVER. No waiver by either Party of the performance of any
provision, condition or requirement herein shall be deemed to be a waiver of,
or in any manner release the other Party from performance of any other
provision, condition or requirement herein; nor shall it be deemed to be a
waiver of, or in any manner release the other Party from future performance of
the same provision, condition, or requirement; nor shall any delay or omission
of a Party in exercising any right hereunder in any manner impair the exercise
of any such right or any like right accruing to it thereafter. No waiver shall
be effective unless made in writing and signed by the Party to be charged with
such waiver.

      11.2 AMENDMENT. This Agreement may be amended only by a written agreement
executed by both Parties that expressly amends this Agreement.

                                      -17-
<Page>

      11.3 AGREEMENT IN COUNTERPARTS. This Agreement, or any amendment thereto,
may be executed in multiple counterparts, each of which shall be deemed an
original Agreement upon the signature by each of the Parties on at least one
counterpart.

      11.4 FURTHER ASSURANCES. Each Party, upon the request of the other Party
agrees to perform any further acts and execute and deliver any other documents,
which may be reasonably necessary to carry out the provisions of this
Agreement.

      11.5 VALIDITY. If any provision of this Agreement is held to be illegal,
invalid, or unenforceable and such invalidity or unenforceability has or would
have a material and substantial negative impact on the rights, duties or
obligations of either Party, then the Parties shall meet to determine if such
negative impact can be eliminated or mitigated. If such negative impact can not
be eliminated or mitigated to the satisfaction of the Party affected thereby,
that Party shall have the right to terminate this Agreement. If any provision of
this Agreement is held to be illegal, invalid, or unenforceable and such
invalidity or unenforceability does not have a material and substantial negative
impact on the rights, duties or obligations of either Party, (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, (1) 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 and (2) such illegality,
invalidity or unenforceability 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.

      11.6 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. In the event of any
conflict between the terms and conditions of this Agreement and the terms and
conditions of any exhibit, schedule or other documents referenced herein, the
terms and conditions of this Agreement shall govern and control.

      11.7 ENTIRE AGREEMENT. This Agreement, including all exhibits,
schedules and descriptions incorporated herein, constitutes and contains the
full and final agreement of the Parties hereto relating to the matters
described herein, and unless otherwise specified herein, this Agreement
supersedes and replaces any and all prior agreements or understandings
(whether written or oral) between or among the Parties regarding the subject
matter hereof, including but not limited to the Letter of Intent between
Warren and Amoco Oil Company dated November 7, 1997.

                                      -18-

<Page>

      11.8 TITLES AND HEADINGS. The titles and headings contained in this
Agreement are for reference purposes only and shall not affect the meaning or
interpretation of this Agreement.

       11.9 BINDING EFFECT. This Agreement and the covenants, obligations,
undertakings, rights and benefits set forth herein shall be binding on and inure
to the benefit of the Parties and their respective authorized successors and
assigns. Neither Party hereto may assign its interest herein without the consent
of the other Party, which consent will not be unreasonably withheld; but no such
consent to assignment shall relieve the assignor of any liability hereunder
unless otherwise agreed in writing by the other Party. No assignment of this
Agreement shall affect or bind the other Party until it shall have been
furnished with an original executed or certified copy of the assignment
instrument.

      11.10 BENEFITS OF AGREEMENT RESTRICTED TO PARTIES. Nothing in this
Agreement, expressed or implied, shall give or be construed to give any person,
other than the Parties hereto (including their Affiliates) and their successors
and assigns, any legal or equitable right, remedy or claim under or in respect
to this Agreement or under any covenant, condition or provision contained
herein; and all such covenants, conditions and provisions shall be for the sole
benefit of the Parties hereto.

      11.11 RESERVATION OF RIGHTS. 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 Agreement or as otherwise provided by law.

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

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

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

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

      11.13 DISCLAIMER OF LIABILITY. NEITHER PARTY SHALL BE LIABLE TO THE
OTHER FOR SPECIAL, INDIRECT, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES
RESULTING FROM OR ARISING OUT OF THIS AGREEMENT, INCLUDING WITHOUT LIMITATION,
LOSS OR USE, INCREASED COST OF OPERATIONS, LOSS OF PROFIT OR REVENUE, OR
BUSINESS INTERRUPTIONS, HOWEVER SAME MAY BE CAUSED AND REGARDLESS OF THE
OTHER PARTY'S NEGLIGENCE (AND REGARDLESS OF WHETHER SUCH NEGLIGENCE IS SOLE,
JOINT,

                                      -19-

<Page>

CONCURRENT, ACTIVE, PASSIVE OR GROSS), FAULT, LIABILITY WITHOUT FAULT, OR
WILLFUL MISCONDUCT. THE DISCLAIMER OF LIABILITY SET FORTH IN THE PRECEDING
SENTENCE SHALL INCLUDE BOTH AFFILIATED AND UNAFFILIATED THIRD PARTY CLAIMS FOR
SPECIAL, INDIRECT, CONSEQUENTIAL, PUNITIVE OR EXEMPLARY DAMAGES.

      11.14 ACKNOWLEDGMENT. EACH OF THE PARTIES HERETO SPECIFICALLY ACKNOWLEDGES
AND AGREES (1) THAT IT HAS A DUTY TO READ THIS AGREEMENT AND THAT IT IS CHARGED
WITH NOTICE AND KNOWLEDGE OF THE TERMS HEREOF, AND (2) THAT IT HAS IN FACT READ
THIS AGREEMENT AND IS FULLY INFORMED AND HAS FULL NOTICE AND KNOWLEDGE OF THE
TERMS, CONDITIONS AND EFFECTS OF THIS AGREEMENT. EACH PARTY HERETO FURTHER
AGREES THAT IT WILL NOT CONTEST THE VALIDITY OR ENFORCEABILITY OF ANY SUCH
PROVISIONS OF THIS AGREEMENT ON THE BASIS THAT THE PARTY HAD NO NOTICE OR
KNOWLEDGE OF SUCH PROVISIONS OR THAT SUCH PROVISIONS ARE NOT "CONSPICUOUS".

      11.15 JOINT EFFORTS. This Agreement shall be considered for all purposes
as prepared through the joint efforts of the Parties, and shall not be construed
against one Party or the other as a result of the preparation, submittal or
other event of negotiation, drafting or execution thereof.

      11.16 CONFLICTS OF INTEREST. 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.
Upon reasonable advance written notice to the other Party, any mutually
agreeable representative(s) authorized by either Party may audit the
applicable records of the other Party solely for the purpose of determining
whether there has been compliance with this Section 11.16.

WARREN PETROLEUM COMPANY,
  LIMITED PARTNERSHIP
By:  Warren Petroleum G.P., Inc.,
     its general partner

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

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

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

                                      -20-

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