Document:

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EXHIBIT 10.32

                                                                         PL-4011

                            UNIT OPERATING AGREEMENT

                                    BETA UNIT

                               SAN PEDRO BAY AREA

                             OUTER CONTINENTAL SHELF

                               OFFSHORE CALIFORNIA

                              Original signed agmt.
                               dtd. August 1, 1982

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                                TABLE OF CONTENTS

ARTICLE                                                                     PAGE
-------                                                                     ----
I       CONFIRMATION OF UNIT AGREEMENT ...................................    2
II      EXHIBITS .........................................................    2
III     DEFINITIONS ......................................................    2
IV      UNIT OPERATOR ....................................................    4
V       APPORTIONMENT OF COSTS AND OWNERSHIP OF PRODUCTION AND PROPERTY ..    4
VI      UNIT EXPENDITURES ................................................    7
VII     MANNER OF EXERCISING SUPERVISION .................................    8
VIII    INDIVIDUAL RIGHTS OF WORKING INTEREST OWNERS .....................    9
IX      AUTHORITY AND DUTIES OF UNIT OPERATOR ............................   11
X       RENTAL, ROYALTY AND MINIMUM ROYALTY ..............................   12
XI      SUBSEQUENT JOINDER, CONTRACTION OR TERMINATION OF UNIT ...........   13
XII     TRANSFERS OF INTEREST ............................................   14
XIII    INSURANCE ........................................................   15
XIV     TAXES ............................................................   17
XV      TITLES ...........................................................   18
XVI     LIABILITY, CLAIMS, AND SUITS .....................................   18
XVII    WITHDRAWAL OF WORKING INTEREST OWNER .............................   19
XVIII   INTERNAL REVENUE PROVISIONS ......................................   21
XIX     EFFECTIVE DATE AND TERM ..........................................   21
XX      ABANDONMENT OF OPERATIONS ........................................   21
XXI     NONDISCRIMINATION ................................................   22
XXII    NOTICES ..........................................................   22
XXIII   EXECUTION ........................................................   23
XXIV    GENERAL ..........................................................   23
XXV     SUCCESSORS AND ASSIGNS ...........................................   23

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                            UNIT OPERATING AGREEMENT

                                    BETA UNIT

                               SAN PEDRO BAY AREA

                  OUTER CONTINENTAL SHELF, OFFSHORE CALIFORNIA

          THIS AGREEMENT, made and entered into as of the 1st day of August,
1982, by the parties who have signed the original of this instrument, a
counterpart thereof or other instrument agreeing to be bound by the provisions
hereof.

                                   WITNESSETH:

          WHEREAS, the parties hereto as Working Interest Owners have executed
an agreement entitled "Unit Agreement for the Development and Operation of the
Beta Unit Area, San Pedro Bay Area, Outer Continental Shelf, Offshore
California", herein referred to as the "Unit Agreement", which among other
things provides for a separate agreement to be entered into by Working Interest
Owners to provide for development and operation of the Unitized Land therein
defined;

          WHEREAS, the Working Interest Owners of Operating Areas 1 and 2 have
constructed an 80 slot platform for drilling and producing operations designated
Platform Ellen, a facilities platform designated Platform Elly and a pipeline to
shore and are conducting drilling and producing operations; and

          WHEREAS, Operations on Leases P-0300, P-0301 and P-0306 are covered by
a separate effective Operating Agreement dated October 1, 1978 and effective
Lease Operating Agreement designating Shell Oil Company as Operator; operations
on Lease P-0296 are covered by a separate Operating Agreement dated February 1,
1976 designating Chevron U.S.A., Inc. as Operator; and Chevron U.S.A. Inc. is
the sole working Interest Owner of Lease P-0306:

          NOW, THEREFORE, in consideration of the mutual agreements herein set
forth, it is agreed as follows:

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                                    ARTICLE I

                         CONFIRMATION OF UNIT AGREEMENT

          1.1 Confirmation of Unit Agreement. The Unit Agreement is hereby
confirmed and by reference made a part of this agreement.

                                   ARTICLE II

                                    EXHIBITS

          2.1 Exhibits. The following Exhibits are incorporated herein by
reference:

               2.1.1 Exhibits A, B and C to the Unit Agreement.

               2.1.2 Exhibit D attached hereto, which is the Accounting
     Procedure applicable to Unit Operations. If there is any conflict between
     this agreement and Exhibit D, this agreement shall control.

               2.1.3 Exhibit E attached hereto which is a plat of the Unit Area
     and designates and describes Operating Areas within the Unit Area.

                                   ARTICLE III

                                   DEFINITIONS

          3.1 Unit Agreement Definitions. The definitions contained in the Unit
Agreement are adopted for all purposes of this agreement. In addition, each term
listed below shall have the meaning stated therefor whenever used in this
agreement.

          3.2 Operating Area is that portion of the Unitized Land which is
outlined on, described in, and designated by number on Exhibit E. Additional
Operating Areas may be created and Operating Areas may be revised and combined
as hereinafter provided.

          3.3 Exploratory Areas. Each Tract of Unitized Land, exclusive of any
portion thereof within an Operating Area, shall constitute a separate
Exploratory Area.

          3.4 Area Participation of a Working Interest Owner within an Operating
Area is the sum of the percentages obtained by multiplying the Working Interest
of such Working Interest Owner in each Tract within an Operating Area by the
Tract Participation of such Tract.

          3.5 Lease Basis means participation by a Party in the proportion that
its undivided Working Interest in a lease or Exploratory Area bears to the
entire Working Interest therein.

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          3.6 Oil and Gas Rights are the rights to explore, develop and operate
lands within the Unit Area for the production of Unitized Substances or to share
in the production so obtained or the proceeds thereof.

          3.7 Party means a party to this agreement including the party acting
as Unit Operator when acting as a Working Interest Owner.

          3.8 Development Well is a well drilled for oil and gas the projected
bottom hole location of which is within an Operating Area.

          3.9 Exploratory Well is a well drilled for oil and gas the projected
bottom hole location of which is within an Exploratory Area.

          3.10 Joint Account is the series of accounts established for the
respective Exploratory Areas, Operating Areas and Platforms showing the charges
and credits accruing because of operations applicable to such areas and
platforms and which are to be shared by the Working Interest Owners on the basis
herein provided.

          3.11 Unit Operations are all operations conducted pursuant to this
agreement and the Unit Agreement.

          3.12 Unit Expenditures are all costs, expenses or indebtedness
incurred by Working Interest Owners or Unit Operator covering more than one
Operating Area pursuant to this agreement and the Unit Agreement for or on
account of Unit Operations.

          3.13 Unit Equipment is all personal property, lease and well
equipment, platforms and other facilities and equipment acquired for use in Unit
Operations.

          3.14 Unitized Land is all submerged land in the Unit area as to which
this Agreement and the Unit Agreement become effective.

          3.15 Unitized Substances are Oil and Gas within or produced from
Unitized land.

          3.16 Drill means to perform all operations reasonably necessary and
incident to the drilling of a well including testing and, if productive of
Unitized Substances, completing and equipping for production, including flow
lines, treaters, separators, and tankage located on the platform, or plugging
and abandoning, if dry.

          3.17 Paying Quantities means that quantity of Unitized Substances
sufficient to yield a return in excess of operating costs.

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          3.18 Common Facilities are facilities such as pipelines, production
platforms and facilities thereon, which are capable of serving more than one
Operating Area.

          3.19 Sub-operator is a party hereto designated as Operator in a
separate Operating Agreement covering a specific portion of the Unit Area.

                                   ARTICLE IV

                                  UNIT OPERATOR

          4.1 Initial Unit Operator. Shell California Production Inc. ("Shell"
or any wholly-owned subsidiary of Shell Oil Company, is designated as Unit
Operator. Shell is recognized as Sub-operator of Leases P-0300, P-03O1 and [??]
and Chevron U.S.A., Inc. is recognized as Sub-operator of Leases P-0296 and each
shall have all of the duties and authorities regarding its operations in its
respective Operating and Exploratory Areas that the Unit Operator has unit this
Agreement regarding Unit Operations.

          4.2 Resignation or Removal of Unit Operator. Resignation or removal of
the Unit Operator shall be governed by the provisions of Article V of the Unit
Agreement.

                                    ARTICLE V

         APPORTIONMENT OF COSTS AND OWNERSHIP OF PRODUCTION AND PROPERTY

          5.1 Apportionment and Ownership Within Operating Areas. All costs
attributable to an Operating Area shall be borne by the Working Interest Owners
in such Operating Area on the basis of the applicable Operating Agreement
referenced on page one hereof, except as otherwise may be specifically provided
herein.

               All production from an Operating Area shall be owned by the
Working Interest Owners in such Operating Area and shared by such Working
Interest Owners on the basis of the applicable Operating Agreement referenced on
page one hereof.

          5.2 Platform Elly. The Working Interest Owners in Operating Area 3
have elected at their sole risk, cost and expense to deliver up to 10,000
barrels/per day of pipeline quality oil (no gas or waste water) to the Deck of
Platform Elly located in Operating Area 1 from Operating Area 3. The treated

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oil shall be metered and delivered into the pipeline to shore. The cost of
operations will conform to Exhibit D, Accounting Procedure.

          5.3 Pipeline to Shore. Working Interest Owners in all Operating Areas
covered by this agreement may participate in the ownership and operation of the
pipeline from Platform Elly to shore based upon [??] usage. Expenditures shall
conform with Exhibit "D". Working Interest shares shall initially be determined
by Operator on the basis of the projections of calendar year throughput for the
next following year which shall also apply retroactively to any preceding
partial year. The initial investment adjustment will include accumulated capital
expenditures plus interest at 12% per annum depreciation. Thereafter, each
year's share will be based upon the [??] year's throughput with annual cash
adjustments of the operating expense and depreciated value of investment costs,
to conform with each year's actual throughput. Payments will be due 30 days
after billing for the adjustment by Operator, and Operator will disperse credit
payments within the ensuing 30 days.

          5.4 New and Revised Operating Areas. The Operating Areas designated on
Exhibit E are recognized as containing Unitized Substances in Paying Quantities.
Any Operating Area may from time to time with the Approval of the Working
Interest Owners therein be revised to include additional lands then regarded as
being capable of production in Paying Quantities, or to exclude lands then
regarded as not being capable of production in Paying Quantities, but no land
shall be excluded from an Operating Area on account of depletion of Unitized
Substances. In the event further drilling in the Unit Area demonstrates the
presence of additional accumulations of Unitized Substances justifying the
construction of an additional platform, an additional Operating Area or Areas
may, with the Approval of the Parties within such proposed Operating Area be
established encompassing those lands which are believed to contain Unitized
Substances in Paying Quantities.

          5.5 Taking in Kind. Each Party shall take in kind or separately
dispose of its proportionate share of all Unitized Substances, exclusive of any
part thereof which may be used in development and producing operations and in
preparing and treating oil or gas for marketing purposes and production
unavoidably lost. Any extra expenditure incurred in the taking in kind or
separate disposition by any Party

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of its proportionate share of Unitized Substances shall be borne by such Party.
Each Party shall execute all division orders and contracts of sale pertaining to
its interest in Unitized Substances, and shall be entitled to receive payment
direct from the purchaser or purchasers thereof for its share thereof.

          5.6 Failure to Take in Kind. In the event any Party shall fail to make
the arrangements necessary to take in kind or separately dispose of its
proportionate share of Unitized Substances, Unit Operator shall have the right,
subject to revocation at will by such Party, but not the obligation, to purchase
such Unitized Substances or sell it to others for the time being, at the best
price obtainable. Any such purchase or sale by Unit Operator shall be subject
always to the right of such Party to exercise at any time its right to take in
kind, or separately dispose of, its share of all Unitized Substances not
previously delivered to a purchaser. All contracts of sale by Unit Operator made
pursuant to this paragraph shall be only for such reasonable periods of time as
are consistent with the minimum needs of the industry under the circumstances,
but in no event shall any such contract be for a period in excess of one year.
Notwithstanding the foregoing, Unit Operator shall not make a sale into
interstate commerce of any other Party's share of gas production without first
giving the other Party sixty (60) days notice of such intended sale.

          5.7 Apportionment and Ownership Within Exploratory Area.
Notwithstanding any other provision herein contained, all Exploratory Wells
drilled within the Unit Area at any time shall be drilled, not under the terms
of this Unit Operating Agreement, but under the terms of the prior existing and
currently effective Operating Agreement covering the Tract on which such well is
located heretofore entered into between the Working Interest Owners of such
Tract, and the costs of any such well shall be borne and the Unitized Substances
produced and saved therefrom shall be owned, prior to the inclusion of such well
in an Operating Area, as in such prior Operating Agreement provided, the
provisions of such Operating Agreement, including the non-consent provisions,
being applicable to such operations. There shall be no readjustment of the costs
of such operations in the event an Operating Area should subsequently be
established or enlarged to encompass such Exploratory Well. If there is

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no currently effective prior operating agreement covering an Exploratory Area,
then the Working Interest Owner of such Exploratory Area shall alone bear and be
responsible for the cost of any Exploratory Well.

                                   ARTICLE VI

                                UNIT EXPENDITURES

          6.1 Basis of Charge to Working Interest Owners. Unit Operator
initially shall pay all Unit Expenditures except those incurred under separate
Operating Agreements covering the respective Operating Areas and Working
Interest Owners shall reimburse Unit Operator for their respective shares
thereof on the basis elsewhere herein provided. All charges, credits and
accounting for Unit Expenditures shall be in accordance with Exhibit D. Each
Party shall bear its proportionate share of all Unit Expenditures incurred in
connection with all Unit Operations which receive the Approval of the Parties.

          6.2 Advance Billings. Unit Operator shall have the right to require
Working Interest Owners to advance their respective shares of estimated Unit
Expenditures by submitting to Working Interest Owners, on or before the 15th day
of any month, an estimate thereof for the succeeding month, with a request for
payment in advance. Within fifteen (15) days thereafter, each Working Interest
Owner shall pay to Unit Operator its share of such estimate. Adjustments between
estimated and actual Unit Expenditures shall be made by Unit Operator at the
close of each calendar month, and the accounts of Working Interest Owners shall
be adjusted accordingly.

          6.3 Commingling of Funds. No funds received by Unit Operator under
this agreement need be segregated or maintained by it as a separate fund but may
be commingled with its own funds.

          6.4 Lien of Unit Operator. Each Working Interest Owner grants to Unit
Operator a lien upon its Oil and Gas Rights in each Tract, its share of Unitized
Substances when produced and its interest in all Unit Equipment as security for
payment of its share of Unit Expenditures, together with interest thereon at the
rate of ten percent (10%) per annum. Unit Operator shall have the right to bring
suit to enforce collection of such indebtedness with or without seeking
foreclosure of the lien. In addition, upon default by any Working Interest

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Owner in the payment of its share of Unit Expenditures, Unit Operator shall have
the right to collect from the purchaser the proceeds from the sale of such
Working Interest Owner's share of Unitized Substances until the amount owned by
such Working Interest Owner, plus interest as aforesaid, has been paid. Each
purchaser shall be entitled to rely upon Unit Operator's written statement
concerning the amount of any default.

          6.5 Unpaid Unit Expense. If any Working Interest Owner fails to pay
its share of Unit Expenditures within sixty (60) days after rendition of a
statement therefor by Unit Operator, each Working Interest Owner agrees, upon
request by Unit Operator, to pay its proportionate part of the unpaid share of
Unit Expenditures of the defaulting Working Interest Owner. The Working Interest
Owners shall be reimbursed by the Unit Operator for the amount so paid, plus any
interest collected thereon, upon receipt by Unit Operator of any past due amount
collected from the defaulting Working Interest Owner. Any Working Interest Owner
so paying a defaulting Working Interest Owner's share of Unit Expenditures shall
be subrogated to the lien and rights herein granted Unit Operator.

          6.6 Offshore Oil Pollution Compensation Fund. Notwithstanding any
provision herein to the contrary, Unit Operator is expressly authorized by
Working Interest Owners to pay the fee imposed by Section 302(d) of the Outer
Continental Shelf Lands Act Amendments of 1978 and to prepare and file such
forms as may be required in connection therewith. Such fee shall be considered a
part of Unit Expenditures for all purposes as defined herein.

                                   ARTICLE VII

                        MANNER OF EXERCISING SUPERVISION

          7.1 Designation of Representatives. Each Working Interest Owner shall
inform Unit Operator in writing of names and addresses of the representative and
alternate who are authorized to represent and bind such Working Interest Owner
with respect to Unit Operations. The representative or alternate may be changed
from time to time by written notice to Unit Operator.

          7.2 Meetings. All meeting of Working Interest Owners shall be called
by Unit Operator upon its own motion or at the request of any Party or Parties
having ten percent (10%) or more of the voting power on each matter to be
considered. Except for emergencies, no meeting shall be called on less than ten
(10) days (exclusive of Saturdays, Sundays

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and legal holidays) advance written notice, with agenda for the meeting
attached. Working Interest Owners represented at the meeting may amend items
included in the Agenda and decide the amended items or other items presented at
the meeting. The representative of Unit Operator shall be chairman of each
meeting.

          7.3 Voting Procedure. Working Interest Owners shall make
Determinations on all matters coming before them as follows:

               7.3.1 Voting Interest. The Parties chargeable with the Unit
     Expenditures of an operation shall have the right to vote thereon in
     proportion to their respective obligations for such expense. Voting on
     other matters shall be on the basis elsewhere herein provided.

               7.3.2 Vote Required. Unless otherwise provided herein or in the
     Unit Agreement, all matters shall be decided by an affirmative vote of
     three or more Working Interest Owners possessing fifty percent (50%) or
     more voting interest.

               7.3.3 Vote at Meeting by Nonattending Working Interest Owner. Any
     Working Interest Owner who is not represented at a meeting may vote by
     letter or telegram addressed to the representative of the Unit Operator if
     its vote is received prior to the vote on the item.

               7.3.4 Poll Votes. Working Interest Owners may vote on and decide,
     by letter or telegram, any matter submitted to Working Interest Owners, if
     no meeting is requested, as provided in Article 8.2, within seven (7) days
     after the proposal is sent to Working Interest Owners. Unit Operator will
     give prompt notice of the results of the voting to all Working Interest
     Owners.

                                  ARTICLE VIII

                  INDIVIDUAL RIGHTS OF WORKING INTEREST OWNERS

          8.1 Reservation of Rights. Working Interest Owners severally reserve
to themselves all their rights, except as otherwise provided in this agreement
and the Unit Agreement.

          8.2 Specific Rights. Each Working Interest Owner shall have, among
others, the following specific rights as to, and only as to, Unit Operations in
which it is sharing in the Unit Expenditures:

               8.2.1 Access to Unitized Land at all reasonable time, weather
     permitting, to inspect Unit Operations. Access to Unitized Land by a
     Working Interest Owner shall be at such Working Interest Owner's sole

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     risk, and such Working Interest Owner agrees to hold Unit Operator and
     other Working Interest Owners harmless of and from and to indemnify Unit
     Operator and other Working Interest Owners against any and all lose or
     liability resulting from or arising out of injuries to such Working
     Interest Owner's personal property, employees, guests or contractors not
     caused by or resulting from the gross negligence or willful misconduct of
     Unit Operator or other Working Interest Owners.

               8.2.2 With respect to wells drilled hereunder, the right, upon
     request, to inspect and receive representative samples of all cores and
     cuttings, and to inspect and receive copies of all logs, including electric
     logs, dipmeter logs and other logs and surveys of the holes which are made.

               8.2.3 The right to participate at its own expense in all
     litigation and all hearings before administrative bodies affecting the
     Unitized Land.

               8.2.4 The right to receive from Unit Operator and Sub-Operator
     currently as obtained daily drilling reports of all wells drilled under the
     terms of this agreement.

               8.2.5 The right to receive from Unit Operator and Sub-Operator
     copies of all reports currently as filed by Unit Operator with govern-
     mental authorities and which are required in connection with Unit
     Operations and the production and disposition of Unitized Substances.

               8.2.6 The right to be present and witness any tests or logging
     conducted in any well drilled hereunder, it being understood that Unit
     Operator and Sub-Operator shall notify orally the affected Working Interest
     Owners of the pendency of any such activity at least four(4) hours in
     advance.

               8.2.7 The right, at its sole cost and expense, to construct and
     operate pipeline and processing facilities required to handle its share of
     Unitized Substances when such facilities are not furnished as a part of
     Unit Operations.

          8.3 Exchange of Well Information. All well logs, charts, analyses,
samples, tests and production information from all wells within the Operating
Areas will be routinely exchanged between the Sub-Operators commencing after
commitment to expenditures for development of the respective Operating Areas.

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          8.4 Treatment of Data and Information. All geophysical, geological,
exploration, reservoir and other data and information normally regarded by
prudent oil operators as sensitive data and information and which is acquired by
Working Interest Owners from any Unit Operation shall be for the sole and
exclusive use and benefit of such Working Interest Owners and their respective
affiliated companies, as hereinafter defined, and shall not be disclosed by them
or their affiliates to any other person unless all Working Interest Owners
involved in the Unit Operation involved consent in writing to such disclosure.
For the purpose of this paragraph an affiliated company shall mean: (1) a
corporation which is the direct or indirect subsidiary of a Party hereto; (2) a
corporation of which a Party hereto is a direct or indirect subsidiary; (3) a
corporation which is a direct or indirect subsidiary of a corporation of which a
Party hereto is a direct or indirect subsidiary; and (4) in the case of Shell
Oil Company, N. V. Koniuklijke Nederlandsche Petroleum Maatschappij, a company
of the Netherlands, the "Shell" Transport and Trading Company Limited, an
English Company, and all other companies, excluding Shell, in whatever country
organized, in which either or both of said named companies shall at the time in
question and directly or indirectly through one or more intermediaries, own or
control fifty percent or more of the voting stock. A corporation shall be deemed
to be a subsidiary of another corporation if the latter owns fifty percent
(50%) or more of all capital stock of the former which has voting rights of any
kind.

          8.5 Publicity Releases. Unit Operator shall prepare and disseminate
all publicity releases concerning Unit Operations; provided, however, Unit
Operator will obtain approval of the other parties except in circumstances
requiring immediate action.

                                   ARTICLE IX

                      AUTHORITY AND DUTIES OF UNIT OPERATOR

          9.1 Exclusive Right to Operate Unit. Subject to the provisions of this
agreement and to Determinations of Working Interest Owners, Unit Operator shall
have the exclusive right and be obligated to conduct Unit Operations.

          9.2 Responsibility of Operator. In the conduct of Unit Operations,
Unit Operator shall be obligated to use only the care and diligence customarily
exercised by a prudent operator in the area in which this Unit is located and

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in conformity with good oil field practice in said area. Unit Operator shall not
be liable in damages to Working Interest Owners for any act done or omitted in
good faith in the performance of the provisions of this agreement, or for errors
of judgement or for loss or damage to any property or Unit Equipment owned by
Working Interest Owners not resulting from the gross negligence or willful
misconduct of Unit Operator.

          9.3 Liens and Encumbrances. Unit Operator shall endeavor to keep the
lands and leases on the Unitized Land free from all liens and encumbrances
occasioned by Unit Operations, except the lien of Unit Operator granted
hereunder.

          9.4 Employees. The number of employees used by Unit Operator in
conducting Unit Operations, and their selection, hours of labor, and
compensation shall be determined by Unit Operator. Such employees shall be the
employees of Unit Operator.

          9.5 Records. Unit Operator shall keep correct books, accounts and
records of Unit Operations.

          9.6 Reports to Working Interest Owners. Subject to paragraph 8.3, Unit
Operator shall furnish to Working Interest Owners copies of periodic report of
Unit Operations made by Unit Operator to regulatory agencies.

          9.7 Reports to Governmental Authorities. Unit Operator shall make all
reports to governmental authorities that it has the duty to make as Unit
Operator.

          9.8 Geological Information. Sub-Operator shall furnish to an affected
Working Interest Owner the material and information described in Article 8.3 and
8.4 hereof with respect to each operating area in which such Working Interest
Owner is sharing in the Unit Expenditures.

          9.9 Use of Unit Operator's Drilling Equipment. Any operation conducted
hereunder which requires a drilling rig may be conducted by Unit Operator by
means of its own tools and equipment provided that the rates to be charged and
the applicable terms and conditions are set forth in a form of drilling contract
which receives the Approval of the Party or Parties chargeable with the Unit
Expenditures incurred in such operation.

                                    ARTICLE X

                       RENTAL, ROYALTY AND MINIMUM ROYALTY

          10.1 Royalty, Minimum Royalty and Rentals. Royalty on Unitized
Substances payable to the United States of America shall be paid in amount or
value

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by Unit Operator when due. The Joint Account for each Operating Area shall be
charged for a share of royalty which shall be calculated on the actual
production for such Operating Area and in accordance with the royalty rate
applicable to the Tract from which the production is obtained. Minimum royalty
and rentals on Unitized Land payable to the United States of America shall be
paid by the lessees of the respective leases. All overriding royalties,
production payments and any other payments of like nature shall be borne and
paid by the Working Interest Owner owning or claiming the interest which is
subject to such payments.

                                   ARTICLE XI

                       CONTRACTION OR TERMINATION OF UNIT

          11.1 Subsequent Joinder. After the effective date hereof, subsequent
joinder in the Unit Agreement and in this agreement by any owner of a Working
Interest in the Unit Area shall be permitted upon such reasonable terms and
conditions as may be agreed upon by the Parties.

          11.2 Contraction of Unit. The Unit Area may, with the consent of the
Director and subject to the consent of all Parties owning a Working Interest in
the lands proposed to be excluded, be contracted to exclude lands in the
following categories: (a) lands as to which exploratory operations are proposed
to be undertaken by the Working Interest Owners thereof and which lands are
reasonably believed to be underlain by a reservoir which is not in pressure and
hydrocarbon communication with any other producing or producible reservoir in
the Unit Area and which reservoir is reasonably believed to not underlie more
than one lease within the Unit Area and which reservoir is reasonably believed
to not be capable of operation from existing platforms in the Unit Area, or (b)
lands as to which exploratory operations have disclosed a reservoir which is not
in communication with any other producing or producible reservoir in the Unit
Area and which separate reservoir lies predominantly outside the Unit Area. Any
contraction applicable to lands in this category (b) shall be conditioned on
reimbursement by the Working Interest Owners of such lands to the other Parties
hereto for Unit Expenditures theretofore incurred in exploratory operations
hereunder applicable to such lands.

          11.3 Termination of Unit. No application for termination of the Unit
Agreement shall be filed with the Supervisor pursuant to Article 15.2 of the
Unit Agreement without the Approval of the Parties voting within all Operating
Areas.

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                              TRANSFERS OF INTEREST

          12.1 Restriction on Transfer. No Party shall assign, sell, mortgage,
pledge as security, or otherwise transfer its Working Interest (undivided or
otherwise) as to any area less than the entire. Unit Area (horizontally and
vertically). Any such interest must be uniform throughout the Joint Area.

          12.2 Consent to Transfer. The assignment, sale, or transfer of any
Interest to a purchaser who is not a Party hereto shall require the consent of
each Party provided that such consent shall not be unreasonably withheld. Such
consent shall be exercised no later than thirty-five (35) days after the receipt
of written notice as provided in Article 12.5.

          12.3 Assumption of Obligations. No transfer of any Working Interests
shall be effective unless the same is made expressly subject to the Unit
Agreement, this agreement and all previous relevant Operating Agreements and the
transferee agrees in writing to assume and perform all obligations of the
transferor under the Unit Agreement and this agreement insofar as relates to the
interest assigned, except that such assumption of obligations shall not be
required in case of a transfer by mortgage or deed of trust as security for
indebtedness.

          12.4 Effective Date. A transfer of Working Interests shall not be
effective as between the Parties until the first day of the month next following
the delivery to Unit Operator of the original or a certified copy of the
instrument of transfer conforming to the requirements of Section 12.3. In no
event shall a transfer of Working Interests relieve the transferring Party of
any obligations accrued hereunder prior to said effective date, for which
purpose any obligation assumed by the transferor to participate in the drilling
of a well or the construction of a platform prior to such effective date shall
be deemed an accrued obligation.

          12.5 Preferential Right of Purchase. Before any Party makes a sale of
all or any part of its Working Interest herein, it shall give to the other
Parties written notice describing the Working Interest proposed to be sold and
stating the price at which and the terms upon which such Party is willing to
sell the same. For a period of thirty (30) days after receipt of such notice the
other Parties who are Working Interest Owners in the affected tract shall have
the right, exercisable by written notice to the selling Party, to purchase the
interest proposed to be sold at the same price and upon the same terms as stated
in said notice; and if none of the Working Interest Owners in the affected tract
exercises this right, then the other parties shall have a similar purchase
option. If said right

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is exercised by any of the Parties, the obligation to purchase shall be subject
to title to such interests being found to be merchantable in the selling Party
and a reasonable time shall be allowed for examination of title thereto. Upon
approval of title the selling Party shall convey such interest to the purchasing
Party or Parties who shall thereupon pay to the selling Party the purchase price
specified therefore; if two or more Parties have elected to purchase such
interest, the purchase shall be made by them proportionately among themselves
based upon their respective adjusted acre feet then in effect within all
Operating Areas. If no Party exercises said right of purchase within said thirty
(30) day period, as above provided, the sealing Party shall be free to sell the
Working Interest described in its notice to any other purchaser provided the
sale is consumated within ninety (90) days after the giving of the initial
notice of proposal to sell and for a price no lower and terms no less favorable
to selling Party than the price and terms specified in such initial notice. Such
interests shall not be sold after the expiration of said period of ninety (90)
days without again giving written notice to the other Parties and affording the
other Parties the right to purchase as hereinabove provided. The provisions of
the foregoing paragraph shall not apply to:

          A.   The mortgage by any Party of all or any part of its Working
               Interest, or

          B.   To the transfer by any Party of all or any part of its Working
               Interest to an affiliated company as defined in Article 8.4, or

          C.   The sale or other disposition by any Party of all or
               substantially all of its oil and gas properties.

          12.6 Priority of this Article. This Article 12 takes the place of and
supersedes in all respects all provisions relating to transfers of interests
contained in prior Operating Agreements affecting the Unitized Land.

                                  ARTICLE XIII

                                    INSURANCE

          13.1 Insurance. Unit Operator agrees at all times to purchase or
provide the following insurance coverage for protection of the Parties, and
shall charge premiums for same to the Joint Account:

          (a)  Workmen's Compensation Insurance and Employers Liability
               Insurance granting full coverage under the Workmen's Compensation
               Laws of the State of California, for all employees

                                      -15-

<page>

               engaged in work for the Joint Account, with limits of $100,000.00
               per accident on Employers Liability. This insurance shall also
               include protection for liability under the Federal Longshoremen's
               and Harbor Workers' Compensation Act as amended, including
               protection with respect to the extension of this act under the
               Outer Continental Shelf Lands Act. Coverage for liability under
               the Jones Act, Death on the High Seas Act, and the General
               Maritime Law shall be included. Coverage shall be amended to
               provide that a claim "in rem" shall be treated as a claim against
               the employer. Provided, however, that Unit Operator may be a
               self-insurer for liability under said compensation laws, in which
               event the only charge that shall be made to the Joint Account
               shall be an amount equivalent to the premiums which would have
               been paid had such insurance been obtained.

          (b)  General Public Liability Insurance in the amount of $100,000 for
               any one person injured in any one accident and $300,000 for more
               than one person injured in any one accident; and $100,000
               property damage per accident. Coverage shall include watercraft.

          (c)  Automotive Public Liability Insurance in the amount of $100,000
               for any one person injured in any one accident and $300,000 for
               more than one person injured in any one accident; and $100,000
               property damage per accident.

          (d)  Operator shall require contractors and subcontractors performing
               work for the Joint Account to provide such Insurance as deemed
               necessary by Operator in relation to the work to be performed by
               said contractors or subcontractors.

          13.2 Liability Not Covered by Insurance. Liability, except that
covered by insurance, against any of the Parties hereto for damages to property
of third persons or injury to or death of third persons arising out of the
operations hereunder, including expenses Incurred in defending claims or actions
asserting liability of this character, shall be borne separately and
individually, and not jointly and collectively, by the parties hereto in
proportion to their

                                      -16-

<page>

responsibility for Unit Expenditures incurred in the operation involved. Any
Party hereto individually may acquire at its own cost such additional insurance
as it desires to protect itself against any liability not covered by insurance
as aforesaid. All insurance purchased individually by a Party to this Agreement
for operations contemplated hereunder shall contain a waiver by the insurance
company of all rights of subrogation in favor of the Parties to this Agreement.

          13.3 Uninsured Losses. Fire, windstorm, tornado, explosion, vandalism,
malicious mischief, or other extended perils insurance will not be carried by
Unit Operator to protect the Parties. Therefore, the Joint Account shall be
charged with all expenditures incurred as a result of fire, windstorm, tornado,
explosion, valdalism, malicious mischief, or other casualties for which
insurance is not required hereunder. Each Party hereby releases Unit Operator
from all claims for loss by or damage to such Party arising out of, in
connection with, or as an incident to, any act or omission, excluding gross
negligence or willful misconduct of Unit Operator or its employees, agents or
contractors, in operations hereunder, provided, this release shall not apply to
Unit Operator's pro rata share of the costs and expenses as otherwise provided
in this Agreement. The obligations of each Party under this Agreement are
separate and individual, and not joint or collective, with the other Parties
hereto.

          13.4 Notice of Loss. Operator shall promptly notify the other Parties
of any loss, damage or claim not covered by insurance carried by Unit Operator
for the Joint Account.

                                   ARTICLE XIV

                                      TAXES

          14.1 Ad Valorem Taxes. Unit Operator shall make and file all necessary
ad valorem tax renditions and returns with the proper taxing authorities
covering all real and personal property of each Working Interest Owner used or
held by Unit Operator in Unit Operations. Unit Operator shall settle assessments
arising therefrom. All such ad valorem taxes shall be paid by Unit Operator and
charged to the Joint Account; provided that, if the interest of a Working
Interest Owner is subject to a separately assessed overriding royalty interest,
production payment, or similar interest, such Working Interest Owner shall be
given credit for the reduction in taxes paid resulting therefrom.

                                      -17-

<page>

          14.2 Other Taxes. Each Working Interest Owner shall pay or cause to be
paid all production, severance, gathering, and other taxes imposed upon or in
respect of the production or handling of its share of Unitized Substances.

                                   ARTICLE XV

                                     TITLES

          15.1 Warranty and Indemnity. Each Working Interest Owner represents
and warrants that it is the owner of the respective Working Interests set forth
opposite its name in Exhibit B, and hereby agrees to indemnify and hold harmless
the other Working Interest Owners from any loss due to failure, in whole or in
part, of its title to any such interest; provided, that such indemnity shall be
limited to an amount equal to the net value that has been received from the sale
or receipt of Unitized Substances attributed to the interest as to which title
failed. Each failure of title will be deemed to be effective, insofar as this
agreement is concerned, as of the first day of the calendar month in which such
failure is finally determined, and there shall be no retroactive adjustment of
Unit Expenditures, or retroactive allocation of Unitized Substances or the
proceeds thereform, as a result of title failure.

                                   ARTICLE XVI

                          LIABILITY, CLAIMS, AND SUITS

          16.1 Individual Liability. The duties, obligations and liabilities of
Working Interest Owners shall be several and not joint or collective. It is not
the purpose or intention of this agreement to create any partnership, mining
partnership, or association and neither this agreement nor the operations
hereunder shall be construed or considered as creating any such relationship.

          16.2 Basis of Responsibility. All Unit Expenditures for cost of
litigation, liens, judgments and settlement of claims incurred in or resulting
from Unit Operations shall be charged to the Parties responsible for the costs
of such Unit Operations.

          16.3 Settlements. Unit Operator may settle any single damage claim or
suit involving Unit Operations but not involving an expenditure in excess of Ten
Thousand Dollars ($10,000.00), provided the payment is in complete settlement of
such claim or suit. If the amount required for settlement ex-

                                      -18-

<page>

ceeds the above specified amount, the affected Working Interest Owners shall
assume and take over the further handling of the claim or suit unless such
authority is expressly delegated to Unit Operator. All costs and expenses of
handling, settling or otherwise discharging such claim or suit shall be Unit
Expenditures. If a claim is made against any Working Interest Owner or if any
Working Interest Owner is sued on account of any matter arising from Unit
Operations and over which such Working Interest Owner individually has no
control because of the rights given Working Interest Owners and Unit Operator by
this agreement and the Unit Agreement, Working Interest Owner shall immediately
notify Unit Operator, and the claim or suit shall be treated as any other claim
or suit involving Unit Operations.

                                  ARTICLE XVII

                      WITHDRAWAL OF WORKING INTEREST OWNER

          17.1 Withdrawal of Working Interest Owner From Tract. No Oil and Gas
Rights may be surrendered by a Working Interest Owner without the unanimous
prior written consent of the other Working Interest Owners in the affected
tract. A Working Interest Owner may withdraw from this agreement by
transferring, without warranty of title either express or implied, to the
Working Interest Owners in the affected tract who do not desire to withdraw all
its Oil and Gas Rights, exclusive of Royalty Interests, together with its
interest in all Unit Equipment and in all wells used in Unit Operations,
provided that such transfer shall not relieve such Working Interest Owner from
any obligation or liability incurred prior to the first day of the month
following receipt by Unit Operator of such transfer. The delivery of the
transfer shall be made to Unit Operator for the transferees. The transferred
interest shall be owned by the transferees proportionately based upon their
respective percentage ownership of the affected tract.

          17.2 Withdrawal of Entire Tract Working Interest From Unit. The entire
Working Interest Ownership of a tract may not be surrendered without the
unanimous prior written consent of the Working Interest Owners of the remaining
tracts. The Working Interest Owners of the tract to be withdrawn may withdraw
from this agreement by transferring, without warranty of title either express or
implied, to the Working Interest Owners of the remaining tracts all its Oil and
Gas Rights, exclusive of Royalty Interests, together with its interest in all
Unit Equipment and in all wells used in Unit Operations, provided that such
transfer shall not relieve such Working Interest

                                      -19-

<page>

Owner from any obligation or liability incurred prior to the first day of the
month following receipt by Unit Operation of such transfer. The delivery of the
transfer shall be made to Unit Operator of such transferees. The transferred
interest shall be owned by the transferees proportionately based upon their
respective percentage ownership of the remaining tracts prior to the transfer.

          17.3 Procedures For Transfer. The transferees under Article 17.1 or
17.2, in proportion to the respective interests so acquired, shall pay the
transferor for its interest in Unit Equipment, the salvage value thereof less
its share of the estimated cost of salvaging same and of plugging and abandoning
all wells then being used or held for Unit Operations, as determined by Working
Interest Owners. In the event such withdrawing owner's interest in the aforesaid
salvage value is less than such owner's share of such estimated costs, the
withdrawing owner, as a condition precedent to withdrawal, shall pay the Unit
Operator, for the benefit of Working Interest Owners succeeding to its interest,
a sum equal to the deficiency. Within sixty (60) days after receiving delivery
of the transfer, Unit Operator shall render a final statement to the withdrawing
owner for its share of Unit Expense, including any deficiency in salvage value,
as determined by Working Interest Owners, incurred as of the first day of the
month following the date of receipt of the transfer. Provided all Unit Expense,
including any deficiency hereunder, due from the withdrawing owner has been paid
in full within thirty (30) days after the rendering of such final statement by
the Unit Operator, the transfer shall be effective the first day of the month
following its receipt by Unit Operator and, as of such effective date,
withdrawing owner shall be relieved from all further obligations and liabilities
hereunder and under the Unit Agreement, and the rights of the withdrawing
Working Interest Owner hereunder and under the Unit Agreement shall cease
insofar as they existed by virtue of the interest transferred.

          17.4 Limitation on Withdrawal. Notwithstanding anything set forth in
Articles 17.1 or 17.2, Working Interest Owners may refuse to permit the
withdrawal of a Working Interest Owner if its Working Interest is burdened by
any overriding royalties, production payments, net proceeds interest, carried
interest, or any other interest created out of the Working Interest in excess of
the lessor's royalty, unless the other Working Interest Owners willing to
accept the assignment agrees to accept the Working Interest subject to such
burdens.

                                      -20-

<page>

                                  ARTICLE XVIII

                           INTERNAL REVENUE PROVISION

          18.1 Internal Revenue Provision. Each of the Parties hereto elects
under the authority of Section 761(a) of the Internal Revenue Code of 1954, to
be excluded from the application of all of the provisions of Subchapter K of
Chapter 1 of Subtitle A of the Internal Revenue Code of 1954. If the income tax
laws of the State of California contain, or may hereafter contain, provisions
similar to those contained in the Subchapter of the Internal Revenue Code of
1954 above referred to under which a similar election is permitted, each of the
Parties agree that such election shall be exercised. Beginning with the first
taxable year of the operation each Party agrees that the deemed election
provided by Regulations Section 1.761-2(b)(2)(ii) will apply and no Party will
file an application under Regulations Section 1.761-2(b)(3)(i) or (ii) to revoke
said election.

                                   ARTICLE XIX

                             EFFECTIVE DATE AND TERM

          19.1 Effective Date. This agreement shall become effective on the date
and at the time that the Unit Agreement becomes effective.

          19.2 Term. This agreement shall continue in effect so long as the Unit
Agreement remains in effect, and thereafter until (a) all unit wells have been
abandoned and plugged or turned over to Working Interest Owners in accordance
with Article XX, (b) all Unit Equipment and real property acquired for the Joint
Account have been disposed of by Unit Operator in accordance with instructions
of Working Interest Owners and (c) there has been a final accounting.

                                   ARTICLE XX

                            ABANDONMENT OF OPERATIONS

          20.1 Termination. Upon termination of the Unit Agreement, the
following shall occur:

               20.1.1 Oil and Gas Rights. Oil and Gas Rights in and to each
          separate Tract shall no longer be affected by this agreement, and
          thereafter the Parties shall be governed by the terms and provisions
          of the leases, contracts and other instruments affecting the separate
          Tracts.

                                      -21-

<page>

               20.1.2 Right to Operate. Working Interest Owners of any Tract
          that desire to take over and continue to operate wells located thereon
          may do so by paying Unit Operator, for credit to the Joint Account,
          the net salvage value of the casing and equipment in and on the wells
          and platforms together with the Common Facilities which are taken
          over, as estimated by Working Interest Owners, and by agreeing to plug
          each well at such time as it is abandoned, remove platforms and
          restore the Unitized Land insofar as is practicable to its original
          conditions, as may be required by law.

               20.1.3 Salvaging Wells. Unit Operator shall salvage as much of
          the casing and equipment in or on wells not taken over by Working
          Interest Owners of separate Tracts as can economically and reasonably
          be salvaged and shall cause the wells to be plugged and abandoned
          properly and in accordance with law.

               20.1.4 Cost of Salvaging. Working Interest Owners shall share the
          cost of salvaging, liquidation or other distribution of assets and
          properties used in Unit Operations in proportion to their respective
          Area Participations.

                                   ARTICLE XXI

                                NONDISCRIMINATION

          21.1 Nondiscrimination. In connection with the performance of
operations hereunder, Unit Operator shall comply with all of the Federal
Contract Provisions contained in the appendix hereto, wherein Unit Operator is
referred to as Contractor, which provisions are incorporated herein by this
reference.

                                  ARTICLE XXII

                                     NOTICES

          22.1 Giving and Receipt. Except as otherwise specified herein, any
notice, consent or statement herein provided or permitted to be given by Unit
Operator or a Party to the Parties shall be given in writing by United States
mail or by telegraph or Telex, properly addressed to each Party to whom given,
with postage or charges prepaid, or by delivery thereof in person to the Party
to whom given; however, if delivered to a corporate Party, it shall not be
deemed given unless delivered personally to an executive officer of such Party
or to its representative designated pursuant to Article 7.1. A notice given

                                      -22-

<page>

under any provision hereof shall be deemed given only when received by the Party
to whom such notice is directed, except that any notice given by United States
registered mail or by telegraph properly addressed to the Party to [??] given
with all postage and charges prepaid, shall be deemed given to and received by
the Party to whom directed forty-eight (48) hours after such notice is deposited
in the United States mail or twenty-four (24) hours after such notice is filed
with an operating telegraph company for immediate transmission by telegraph, and
also except that a notice to Unit Operator shall not be deemed given until
actually received by it.

          22.2 Proper Addresses. Each Party's proper address shall be deemed to
be the address set forth under or opposite its signature hereto unless and until
such Party specifies another post office address within the continental limited
of the United States by not less than ten (10) days prior written notice to all
other Parties.

                                  ARTICLE XXIII

                                    EXECUTION

          23.1 Original, Counterpart, or Other Instrument. A party may become a
Party to this agreement by executing the original of this instrument, a [??]
part thereof or other instrument agreeing to be bound by the provisions hereof.
The execution of any such instrument shall have the same effect as if all the
Parties had executed the same instrument.

                                  ARTICLE XXIV

                                     GENERAL

          24.1 Gender and Number. As used herein, whenever the context so
requires, the neuter gender includes the masculine and the feminine, and the
singular includes the plural, and vice versa.

          24.2 Headings. The table of contents contained in this agreement and
the title headings of the respective articles of this agreement are inserted
for convenience only and shall not be deemed to be part of this agreement or
considered in construing this agreement.

                                   ARTICLE XXV

                             SUCCESSORS AND ASSIGNS

          25.1 Successors and Assigns. The provisions hereof shall be covenants
running with the lands, leases and interests covered hereby and shall be binding
upon and inure to the benefit of the respective heirs, devisees,

                                      -23-

<page>

legal representatives, successors and assigns of the Parties hereto.

          IN WITNESS WHEREOF, the Parties hereto have executed this agreement on
the dates opposite their respective signatures.

                                        UNIT OPERATOR, SUB-OPERATOR AND
                                        WORKING INTEREST OWNER

Date: August 2, 1982                    SHELL CALIFORNIA PRODUCTION INC.

Address: P. O. Box 4578
         Houston, TX 77210              By: /s/ [ILLEGIBLE]
Telex:                                      ------------------------------------
         ----------------------------                Attorney-in-Fact

                                        SUB-OPERATOR AND WORKING
                                        INTEREST OWNER

Date:                                   CHEVRON U.S.A. INC.
         ----------------------------
Address: 2120 Diamond Boulevard
         Concord, CA 94520              By:
Telex:   910-372-7340                       ------------------------------------
         SOCOSAN SFO

Date:    8-10-82                        PETRO LEWIS BETA COMPANY JOINT VENTURE

Address: 5500 Ming Avenue, Suite 300
         Bakersfield, California        By: /s/ Richard E. Bennett
         93309                              ------------------------------------
Telex:   910-327-1010                       Richard E. Bennett
                                            Vice President,
                                            Petro-Lewis Funds, Inc.,
                                            Managing Venturer

Date:                                   AMINOIL USA, INC.
         ----------------------------
Address: P. O. Box 94193
         Houston, TX 77018              By:
Telex:   762060                             ------------------------------------
                                        Attest:
                                                --------------------------------

Date:                                   SANTA FE ENERGY COMPANY
         ----------------------------
Address: 10737 Shoemaker Avenue
         Santa Fe Springs, CA 90670     By:
Telex:   910-583-1928                       ------------------------------------
                                        Attest:
                                                --------------------------------

Date:                                   UNION OIL COMPANY OF CALIFORNIA
         ----------------------------
Address: P. O. Box 7600
         Los Angeles, CA 90051          By:
Telex:                                      ------------------------------------
         ----------------------------

                                      -24-

<page>

legal representatives, successors and assigns of the Parties hereto.

          IN WITNESS WHEREOF, the Parties hereto have executed this agreement on
the dates opposite their respective signatures.

                                        UNIT OPERATOR, SUB-OPERATOR AND
                                        WORKING INTEREST OWNER

Date: August 2, 1982                    SHELL CALIFORNIA PRODUCTION INC.

Address: P. O. Box 4578
         Houston, TX 77210              By: /s/ [ILLEGIBLE]
Telex:                                      ------------------------------------
         ----------------------------                Attorney-in-Fact

                                        SUB-OPERATOR AND WORKING
                                        INTEREST OWNER

Date:                                   CHEVRON U.S.A. INC.
         ----------------------------
Address: 2120 Diamond Boulevard
         Concord, CA 94520              By:
Telex:   910-372-7340                       ------------------------------------
         SOCOSAN SFO

Date:                                   PETRO LEWIS BETA COMPANY JOINT VENTURE
         ----------------------------
Address:
         ----------------------------   By:
         ----------------------------       ------------------------------------
Telex:
         ----------------------------

Date: August 6, 1982                    AMINOIL USA, INC.
Address: P. O. Box 88
         Huntington Beach, CA 92648     By: /s/ W. L. Donnelly
Telex:   910-596-1304                       ------------------------------------
                                            W. L. Donnelly, Vice President

                                        Attest: /s/ J. H. Loeb
                                                --------------------------------
                                                J. H. Loeb, Asst. Secretary

Date:                                   SANTA FE ENERGY COMPANY
         ----------------------------
Address: 10737 Shoemaker Avenue
         Santa Fe Springs, CA 90670     By:
Telex:   910-583-1928                       ------------------------------------
                                        Attest:
                                                --------------------------------

Date:                                   UNION OIL COMPANY OF CALIFORNIA
         ----------------------------
Address: P. O. Box 7600
         Los Angeles, CA 90051          By:
Telex:                                      ------------------------------------
         ----------------------------

                                      -24-

<page>

legal representatives, successors and assigns of the Parties hereto.

     IN WITNESS WHEREOF, the Parties hereto have executed this agreement on the
dates opposite their respective signatures.

                                        UNIT OPERATOR, SUB-OPERATOR AND
                                        WORKING INTEREST OWNER

Date:                                   SHELL CALIFORNIA PRODUCTION INC.
         ----------------------------
Address: P. O. Box 4578
         Houston, TX 77210              By:
Telex:                                      ------------------------------------
         ----------------------------                Attorney-in-Fact

                                        SUB-OPERATOR AND WORKING
                                        INTEREST OWNER

Date:                                   CHEVRON USA, INC.
         ----------------------------
Address: P. O. Box 8000
         Concord, CA 94524              By:
Telex:   910-372-7340                       ------------------------------------
         SOCOSAN SFO

Date:                                   PETRO LEWIS BETA COMPANY JOINT VENTURE
         ----------------------------
Address:
         ----------------------------   By:
                                            ------------------------------------
         ----------------------------
Telex:
         ----------------------------

Date:                                   AMINOIL USA, INC.
         ----------------------------
Address: P. O. Box 94193
         Houston, TX 77018              By:
Telex:   762060                             ------------------------------------
                                        Attest:
                                                --------------------------------

Date: April 22, 1983                    SANTA FE ENERGY COMPANY

Address: 10737 Shoemaker Avenue
         Santa Fe Springs, CA 90670     By: /s/ G.N. Shirley
                                            ------------------------------------
                                            G.N. Shirley, Vice President
Telex:   910-583-1928                   Attest:
                                                --------------------------------
                                                K.M. Bates, Assistant Secretary

Date:                                   UNION OIL COMPANY OF CALIFORNIA
         ----------------------------
Address: P. O. Box 7600
         Los Angeles, CA 90051          By:
Telex:                                      ------------------------------------
         ----------------------------

                                      -24-

<page>

legal representatives, successors and assigns of the Parties hereto.

          IN WITNESS WHEREOF, the Parties hereto have executed this agreement on
the dates opposite their respective signatures.

                                        UNIT OPERATOR, SUB-OPERATOR AND
                                        WORKING INTEREST OWNER

Date: August 2, 1982                    SHELL CALIFORNIA PRODUCTION INC.

Address: P. O. Box 4578
         Houston, TX 77210              By: /s/ [ILLEGIBLE]
Telex:                                      ------------------------------------
         ----------------------------                Attorney-in-Fact

                                        SUB-OPERATOR AND WORKING
                                        INTEREST OWNER

Date: March 25, 1983                    CHEVRON U.S.A. INC.

Address: 2120 Diamond Boulevard
         Concord, CA 94520              By: /s/ [ILLEGIBLE]
Telex:   910-372-7340                       ------------------------------------
         SOCOSAN SFO                        Assistant Secretary

Date:                                   PETRO LEWIS BETA COMPANY JOINT VENTURE
         ----------------------------
Address:
         ----------------------------   By:
                                           ------------------------------------
         ----------------------------
Telex:
         ----------------------------

Date:                                   AMINOIL USA, INC.
         ----------------------------
Address: P. O. Box 94193
         Houston, TX 77018              By:
Telex:   762060                             ------------------------------------
                                        Attest:
                                                --------------------------------

Date:                                   SANTA FE ENERGY COMPANY
         ----------------------------
Address: 10737 Shoemaker Avenue
         Santa Fe Springs, CA 90670     By:
Telex:   910-583-1928                       ------------------------------------
                                        Attest:
                                                --------------------------------

Date: MAR 28 1983                       UNION OIL COMPANY OF CALIFORNIA

Address: P. O. Box 7600
         Los Angeles, CA 90051          By: /s/ [ILLEGIBLE]
Telex:   (213) 304-7798                     ------------------------------------
                                            It's attorney-in-fact

                                      -24-

<page>

Date: August 9, 1982                    HAMILTON BROTHERS OIL COMPANY

Address: 1600 Broadway, Suite 2600
         Denver, CO 80202               By: /s/ [ILLEGIBLE]
                                            ------------------------------------
Telex: 45-851

Date: August 9, 1982                    HAMILTON BROTHERS EXPLORATION C0MPANY

Address:  1600 Broadway, Suite 2600
          Denver, CO 80202              By: /s/ [ILLEGIBLE]
                                            ------------------------------------
Telex: 45-851                               VICE PRESIDENT

Date: August 9, 1982                    HAMILTON BROTHERS CORPORATION

Address : 1600 Broadway, Suite 2600
          Denver, CO 80202              By: /s/ [ILLEGIBLE]
                                            ------------------------------------
Telex: 45-851                               VICE PRESIDENT

                                        MINOCO UAQ, LTD., a  California
ATTEST [ILLEGIBLE]                      limited partnership
       ------------------------------
Date: 4-12-83                           By: Minoco Southern Corporation,
                                            a Nevada corporation,
                                            managing general partner
Address: MINOCO
         2029 Century Park East,
         Second Floor, Los Angeles,     By: /s/ W. E. Bauer
         California 90067                   ------------------------------------
                                            W. E. Bauer, Vice President
TWX: 910-490-1974

                                        MINOCO 1980-IPLC OIL AND GAS PROGRAM,
ATTEST [ILLEGIBLE]                      a California limited partnership
       ------------------------------

Date: 4-12-83                           By: Minoco Southern Corporation,
                                            a Nevada corporation, managing
                                            general partner
Address: MINOCO
         2029 Century Park East,
         Second Floor, Los Angeles,     By: /s/ W. E. Bauer
         California 90067                   ------------------------------------
                                            W. E. Bauer, Vice President
TWX: 910-490-1974

                                        PACIFIC FEDERAL VENTURES, a California
                                        joint venture comprised of Pacific [??]
                                        Investments, Inc., a California
                                        corporation and MGC Ventures U.S., Ltd.,
                                        a California corporation

ATTEST [ILLEGIBLE]
       ------------------------------   By: MGC Ventures U.S., Ltd., as
Date: 4-12-83                               attorney-in-fact for Pacific

Address: MINOCO
         2029 Century Park East,        By: /s/ W. E. Bauer
         Second Floor, Los Angeles,         ------------------------------------
         California 90067                   W. E. Bauer, Vice President

TWX:     910-490-1974

                                        By: MGC Ventures U.S., Ltd.
ATTEST [ILLEGIBLE]
       ------------------------------

                                        By: /s/ W. E. Bauer
                                            ------------------------------------
                                            W. E. Bauer, Vice President

                                      -25-<PAGE>

EXHIBIT 10.33

                                   AMENDMENT
                                   ---------

         THIS AGREEMENT, made and entered into this 15th day of April, 1983, by
and between the parties whose names are subscribed to below.

                                  WITNESSETH:

         WHEREAS, the parties hereto have executed that certain "Unit Operating
Agreement, Beta Unit, San Pedro Bay Area, Outer Continental Shelf, Offshore
California" dated as of August 1, 1982, (hereinafter called "Unit Operating
Agreement:); and

         WHEREAS, the parties desire to amend said Unit Operating Agreement in
the particulars hereinafter set forth;

         NOW, THEREFORE, in consideration of the mutual benefit to be obtained
the parties agree as follows:

         1. Article 12.2 is hereby amended by inserting after "...consent of
each party" the words "owning a Working Interest in the affected Lease".

         2. Article 12.5 is hereby deleted and the following inserted in its
place

                  12.5 Preferential Right of Purchase. Except as hereinabove
                  provided, any preferential right of purchase shall be governed
                  by and implemented in accordance with the prior existing and
                  currently effective operating agreement covering the affected
                  Lease.

         Except as herein modified, said Unit Operating Agreement remains in
full force and effect.

         This instrument may be executed in counterpart with the same effect as
if all parties had executed the same instrument.

                                      -1-

<page>

         IN WITNESS whereof the parties have executed this instrument as of the
date first written above.

HAMILTON BROTHERS OIL COMPANY                SHELL CALIFORNIA PRODUCTION INC.

By: /s/ signature                                By: /s/ T.L. Marshall
    --------------------------------             -------------------------------
    Executive Vice President                     Attorney-in-Fact
                                                 T.L. Marshall

HAMILTON BROTHERS EXPLORATION CO.            AMINOIL USA, INC.

By: /s/ signature                                By: /s/ D.E. Vanderberg
    --------------------------------             -------------------------------
    Vice President                               D.E. Vanderberg Contract Agent
                                                 ATTEST

HAMILTON BROTHERS CORPORATION                SANTA FE ENERGY COMPANY

By: /s/ signature                            By: /s/ G.N. Shirley
    --------------------------------             -------------------------------
    Vice President                               G.N. Shirley, Vice President

                                                 ATTEST /s/ K.M. Bales
                                                 Assistant Secretary

CHEVRON USA, INC.                            PETRO LEWIS BETA COMPANY JOINT
                                             VENTURE

By: /s/ signature                            By: /s/ Richard E. Bennett
    --------------------------------             -------------------------------
    Title                                        Richard E. Bennett, Vice
                                                 President, Petro Lewis Funds,
                                                 Inc., Managing Venturer

UNION OIL COMPANY OF CALIFORNIA              MINOCO UAQ, LTD., a California
                                             Limited Partnership

By: /s/ K.J. Robertson                       By: Minaco Southern Corporation, a
   ---------------------------------             Nevada Corporation, Managing
   K.J. Robertson                                General Partner
   Its Attorney-in-Fact

ATTEST /s/ signature

PACIFIC FEDERAL VENTURES, a                  By: /s/ W.E. Bauer
California Joint Venture comprised               -------------------------------
of Pacific Energy Investments, Inc.              W.E. Bauer, Vice President
a California Corporation and MGC
Ventures U.S. Ltd., a California             MINACO 1680 - ILPC OIL AND GAS
Corporation                                  PROGRAM, a California Limited
                                             Partnership

By: MGC Ventures, U.S., Ltd.                 By: Minoco Southern Corporation, a
                                                 Nevada Corporation, Managing
By: /s/ W.E. Bauer                               General Partner
   --------------------------------
   W.E. Bauer, Vice President                By: /s/ W.E. Bauer
                                                 -------------------------------
ATTEST /s/ signature                             W.E. Bauer, Vice President

By: MGC Ventures, U.S., Ltd.                 ATTEST /s/ signature
    as Attorney-in-Fact for
    Pacific Energy Investments,
    Inc.

By: /s/ W.E. Bauer
    --------------------------------
    W.E. Bauer, Vice President

ATTEST /s/ signature

STATE OF CALIFORNIA     )
                        ) ss.
COUNTY OF ORANGE        )

On April 21, 1983, before me, the undersigned, a Notary Public in and for said
County and State, personally appeared D.E. Vanderberg, personally known to me
(or proved to me on the basis of satisfactory evidence) to be the Contract Agent
of Aminoil USA, Inc. the corporation that executed the within instrument, and
personally known to me (or proved to me on the basis of satisfactory evidence)
to be the person who executed the within instrument on behalf of the corporation
therein named, and acknowledged to me that such corporation executed the within
instrument pursuant to its by-laws or a resolution of its board of directors.

[SEAL]                                  /s/ Ellen Nannie
                                        ----------------------------------------
                                        Notary Public in and for said County
                                        and State

                                      -2-

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