<Page>

EXHIBIT 10.11

                             GAS PURCHASE AGREEMENT

         This Agreement, made and entered into as of October 1, 1999, by and
between Ozark Gas Gathering, L.L.C. ("OGG") and Energas Corp. ("Producer").

         WHEREAS, Producer currently owns or represents a working interest in
certain well(s) that it desires to connect to OGG's various gathering
system(s) located in the State of Oklahoma; and

         WHEREAS, OGG agrees to install certain facilities to effect receipt
and purchase of natural gas production owned or marketed by Producer from
certain well(s), described on Exhibit "A" attached hereto and made a part
hereof, subject to the following terms and conditions.

         NOW THEREFORE, in consideration of the mutual covenants and
agreements herein contained, OGG and Producer hereby agree as follows:

1.       FACILITIES. OGG will, at its sole cost and expense, acquire, construct,
         own, operate and maintain all taps, rights-of-way, measurement,
         compression and dehydration equipment and related facilities
         ("Facilities") deemed necessary, in the sole discretion of OGG, to
         install receipt points ("Receipt Point(s)") to effect receipt of
         natural gas production from the well(s) into the OGG gathering system.

2.       PRESSURE. OGG shall endeavor to provide and maintain, or cause to be
         provided and maintained, a monthly average line pressure ("MALP") at
         each Receipt Point not to exceed the contract maximum pressure ("CMP")
         as specified on the attached Exhibit "A". The MALP for each Receipt
         Point shall be derived solely from the data provided by OGG and
         approved by Energas. If the MALP exceeds the CMP at a particular
         Receipt Point for a period of thirty (30) consecutive days, Producer
         may notify OGG in writing within (30) days of the occurrence
         (Producer's Notification). OGG shall have thirty (30) days after
         receipt of Producer's Notification to respond to Producer with OGG's
         plan to reduce the MALP at the Receipt Point(s) to a pressure less than
         or equal to the CMP and the proposed completion date of such plan (OGG
         Response Period). If OGG has not reduced the MALP at the Receipt Point
         to a pressure less than or equal to the CMP within a period of sixty
         (60) days after OGG's receipt of Producer's Notification, Producer
         shall have the option to either (1) request and receive a release of
         the affected well(s) from this Agreement, effective the first day of
         the month following the expiration of the OGG Response Period or (2)
         continue to deliver gas to OGG pursuant to the terms and conditions of
         this Agreement less a six cent (6 cent) reduction in the Service Fee
         as stated on Exhibit "A" effective the first day of the month following
         the expiration of the OGG Response Period. The initial Service Fee as
         stated on Exhibit "A'" will be re-established effective the first day
         of the month following the period when OGG has maintained the MALP at a
         pressure less than or equal to the CMP.

3.       PRIMARY TERM. The Primary Term of this Agreement shall commence on
         October 1, 1999 under the terms of this Agreement, and shall continue
         in effect for a period of six (6) months, until March 31, 2000.
         Thereafter, this Agreement shall remain in effect on a month-to-month
         basis until terminated by either party effective the first day of the
         month following thirty (30) days written notice prior to the end of the
         Primary Term or any annual extension thereto.

4.       COMMITMENT. Producer covenants and agrees that all natural gas produced
         from well(s) and/or dedicated acreage described on Exhibit "A" in which
         Producer currently holds, represents, or markets shall at all times
         throughout the Primary Term, or any extension thereof, be dedicated
         exclusively to OGG under the terms of this Agreement. Producer, at its
         sole discretion, shall have the right to dedicate additional wells or
         acreage to this Agreement. The type of dedication is specified on
         Exhibit "A". Furthermore, Producer commits to deliver 90,000 MMBtu in
         natural gas to OGG from the well(s) described on Exhibit "A" during the
         Primary Term of this Agreement as referenced above in Paragraph 1 to
         compensate OGG for the cost of the metering facilities installed to
         connect the well(s). At the end of the Primary Term, if the total
         volume of natural gas delivered to OGG at the well(s) described on
         Exhibit "A" is less than 90,000 MMBtu, Producer

                                    Page 1
<Page>

         agrees to pay OGG a fee of $0.18 per MMBtu multiplied times the
         deficit volume. Such payment shall be made within (15) days of
         receipt of OGG's invoice. The deficit volume shall be calculated by
         deducting the volume delivered to OGG from the well(s) described on
         Exhibit "A" during the Primary Term from 90,000 MMBtu. It is
         understood that all volumes measured at the well(s) described on
         Exhibit "A" shall be credited toward the volume commitment.

5.       PRICE. OGG shall pay to Producer on a monthly basis, as full
         compensation for the natural gas and all of its components delivered to
         OGG, an amount equal to the Index Price published in the first "Inside
         F.E.R.C. Gas Market Report" issue of each month for Reliant Energy
         Gas Transmission Co. (East Zone) multiplied by the MMBtu's delivered by
         Producer at the Receipt Point. Payment shall be made on or before the
         last day of the month following the production month. The price payable
         hereunder shall be inclusive of all production, severance, excise and
         similar taxes imposed or levied by the state or any other governmental
         agency on the gas produced, sold or delivered hereunder. Producer shall
         pay all royalty and taxes with respect to the gas delivered hereunder.
         In the event OGG is required to remit taxes on behalf of Producer, the
         amount paid shall be deducted from the payment due Producer.

6.       FEES AND FUEL. For applicable services, OGG shall deduct eighteen cents
         (18 cents) per MMBtu from the amount due Producer pursuant to
         Paragraph 5. In addition, OGG shall deduct for fuel four percent (4%)
         of the Price as described in Paragraph 5, multiplied by the volume in
         MMBtu for gas delivered by Producer at the Receipt Point.

7.       TRANSPORTER'S RESERVATIONS. All gas received by OGG pursuant to this
         Agreement shall comply with the terms and provisions contained in the
         Ozark Gas Transmission, L.L.C. FERC Gas Tariff ("Tariff"), as may be
         amended from time to time, which is incorporated herein by reference.
         In the event of a conflict between any provision of this Agreement and
         the Tariff, this Agreement shall control.

8.       QUALITY SPECIFICATIONS. OGG hereby expressly agrees to waive the
         quality specification requirement for water vapor content as stated in
         the Tariff. Furthermore, all gas purchased hereunder will be on a
         saturated basis. With regard to the other quality specifications
         contained in the Tariff, if any tests reveal that any gas does not
         conform to said specifications, then Producer shall have the right to
         promptly bring the gas into conformance. If Producer does not elect to
         treat said non-conforming gas to effect conformance, OGG hereby
         reserves the right to either (i) treat said gas, or cause it to be
         treated, to effect conformance and/or take such action as OGG, in its
         sole judgment, deems necessary to reduce or eliminate the effects that
         may result from receiving non-conforming gas into the Facilities and
         charge actual costs as determined by OGG, or (ii) continue to accept
         said gas without treating, or (iii) refuse to accept gas not conforming
         to the quality specifications. However, acceptance of non-conforming
         gas shall not constitute any continuing waiver of OGG's rights to
         accept or reject all or part of any gas under this Agreement not
         conforming to the quality specifications. If OGG elects to treat the
         gas as provided in Section (i) of this paragraph, OGG shall provide
         Energas with a statement, in writing, estimating the cost to reduce or
         eliminate the effects of the non-conforming gas. Energas shall have ten
         (10) days from receipt of OGG's statement to notify OGG in writing of
         it's election. If Energas rejects OGG's offer to treat the
         non-conforming gas as provided in Section (i), the non-conforming gas
         shall then be released from this Agreement within ten (10) days of
         OGG's receipt of Energas' written rejection.

9.       MODIFICATIONS. With the exception of the modifications contemplated
         under the paragraphs with descriptive headings of "Transporter's
         Reservations" and "Additional Wells" herein, modifications to this
         Agreement will only be allowed through express written agreement
         executed by authorized officers or representatives of both OGG and
         Producer.

10.      WARRANTY/INDEMNIFICATION. Each party hereby warrants to the other that
         at the time of receipt or delivery of gas hereunder, it will have the
         right to receive or deliver, as the case may be, such gas, and that
         such gas shall be free and clear of all liens and adverse claims; and
         each party agrees, with respect to the gas received or delivered by it,
         to indemnify the other party against all

                                    Page 2
<Page>

         suits, actions, debts, accounts, damages, costs (including attorney
         fees), losses and expenses arising from or out of any adverse claim of
         any and all persons to or against said gas while that party has
         responsibility for the gas.

11.      FORCE MAJEURE. If either party is rendered unable, wholly or in part,
         by force majeure or any other cause of any kind not reasonably within
         its control, other than financial, to perform or comply with any
         obligation or condition of this Agreement, upon giving written notice
         and reasonably full particulars to the other party as soon as
         reasonably possible, such obligation or condition shall be suspended
         during the continuance of the inability so caused and such party shall
         be relieved of liability and shall suffer no prejudice for failure to
         perform the same during such period; provided, obligations to make
         payment then due for gas transported hereunder shall not be suspended
         and the cause for suspension (other than labor disputes, strikes or
         lockouts) shall be remedied so far as possible with reasonable
         dispatch. Settlement of strikes, lockouts and labor disputes shall be
         wholly within the discretion of the party having the difficulty. The
         term "force majeure" shall include, without limitation by the following
         enumeration, acts of God and the public enemy, the elements, fire,
         accidents, breakouts, strikes and any other industrial, civil or public
         disturbance, inability to obtain or delay in obtaining rights-of-way,
         material, supplies, permits or labor, any act or omission by parties
         not subject to control by the party having difficulty, and any laws,
         orders, rules, regulations, acts or restraints of any government or
         governmental body or authority, civil or military.

12.      AUDIT RIGHTS. Either party hereto shall have the right at any and all
         reasonable times to examine the books and records of the other party to
         the extent necessary to verify the accuracy of any statement, charge,
         computation or demand made under or pursuant to this Agreement. All
         books and records shall be kept for two (2) years from the date of
         production In addition, any claim by either party of error as to the
         quantity, price, fees or deductions pursuant to this Agreement shall be
         waived unless written notice of such claim is given to the other party
         within two years (2) following the production month.

13.      TRANSFER OF TITLE. Title to the gas shall transfer to OGG at the
         Receipt Point(s). As between the parties hereto, Producer shall be in
         control and in possession of the gas prior to such gas being received
         hereunder by OGG at the Receipt Point(s) and responsible for any
         damages, losses or injuries caused thereby, and upon OGG's physical
         receipt of such gas at the Receipt Point(s), OGG shall thereafter be
         deemed to be in exclusive control and possession of such gas, and
         responsible for any injuries or damages caused thereby; provided,
         however, neither party shall be indemnified for its own omissions or
         negligent acts.

14.      DESCRIPTIVE HEADINGS. The descriptive headings of the provisions of
         this Agreement are formulated and used for convenience only and shall
         not be deemed to affect the meaning or construction of any such
         provision.

15.      EXECUTION AND ASSIGNMENT. This Agreement shall not become a binding
         contract between the parties unless and until it has been executed by
         duly authorized officers or representatives of both Producer and OGG.
         Upon full execution, this Agreement shall be binding upon the parties
         hereto and their representatives, heirs, successors and assigns. All
         references to the parties herein shall include any designee or agent of
         the respective parties. This Agreement may be assigned by either party
         hereto upon written notice to the other party, but no assignment shall
         relieve either party of its obligations hereunder unless such party is
         expressly released in writing from said obligations by the party to
         which it is obligated. Such notice by the assigning party shall include
         furnishing the other party with a copy of the fully executed
         instrument(s) effecting such assignment, and any change in ownership
         shall not become effective or binding until it receives said
         document(s).

16.      APPLICABLE LAW. This Agreement shall be governed by the laws of the
         State of Oklahoma.

                                     Page 3
<Page>

17.      NOTICES. Written notification, as provided for in this Agreement, shall
         be deemed given when physically delivered to the other party in person,
         when transmitted to the other party by confirmed facsimile or
         electronic transmission, or when deposited in the U.S. Mail or with a
         delivery service, postage prepaid, as follows:

         PRODUCER                           OGG
           Energas Corp.                      Ozark Gas Gathering, L.L.C.
           6601 Broadway Ext. Suite 300       P.O. Box 24300
           Oklahoma City, OK 73116-8214       Oklahoma City, OK 73124-0300

           Attn: Mr. Jerry Parry              Attn:  Contract Administration

           Tel:  (405) 879-1752               Tel:   (405) 525-7788
           Fax:  (405) 879-0175               Fax:   (405)  557-6886

IN WITNESS WHEREOF, the undersigned authorized officers or representatives of
OGG and Producer have executed this Agreement by signature below.

                                       ENERGAS CORP.

                                           By:      /s/ Jerry Parry
                                                    ----------------------------

                                           Name:    JERRY PARRY
                                                    ----------------------------

                                           Title:   Land Manager
                                                    ----------------------------


                                       OZARK GAS GATHERING, L.L.C.

                                           By:      /s/ Darrell Marshall
                                                    ----------------------------

                                           Name:    Darrell Marshall
                                                    ----------------------------

                                           Title:   Manager, Ozark Business Unit
                                                    ----------------------------


                                    Page 4
<Page>

                                   EXHIBIT "A"

    This Exhibit "A" is for all purposes attached to and made a part of that
certain Agreement dated October 1, 1999 by and between OGG and Energas,
Corp. covering well(s) and/or dedicated acreage described below

<Table>
<Caption>
-------------- --------------- --------------- ------------ -------------- -------------- ---------------- -------------------------
                                                                             CONTRACT          GROSS                 FEES
                                                                              MAXIMUM       REPRESENTED            $/MMBTU
                                                                             PRESSURE         WORKING
   STATION                         LEGAL                     DEDICATION       ("CMP")        INTEREST      SERVICE        FUEL
   NUMBER        WELL NAME      DESCRIPTION      COUNTY         TYPE          (PSIG)            (%)           FEE       DEDUCTION
-------------- --------------- --------------- ------------ -------------- -------------- ---------------- ---------- --------------
<S>            <C>             <C>             <C>          <C>            <C>            <C>              <C>        <C>
                 John Wells      28-09N-21E      Haskell      Wellbore          70            100.00          .18          4%
                    1-28
-------------- --------------- --------------- ------------ -------------- -------------- ---------------- ---------- --------------
</Table>








                                    Page 5