Exhibit 10(z)

                        ASSET PURCHASE AND SALE AGREEMENT

                THIS AGREEMENT made as of the 4th, of May, 2001.

AMONG:

                       TESTCO INC. de MEXICO, S.A. de C.V.
     a corporation incorporated under the laws of the United Mexican States
                                 (the "Vendor")

                                     - and -

                                 ITS-TESTCO, LLC
                   a limited liability company organized under
           the laws of the State of Oklahoma, United States of America
                               (the "Shareholder")


                                     - and -

                PD OILFIELD SERVICES MEXICANA, S. de R.L. de C.V.
     a corporation incorporated under the laws of the United Mexican States
                                (the "Purchaser")

WHEREAS:

A.   The Vendor is the owner of the Assets;

B.   The Shareholder is the legitimate owner of 100% of the outstanding shares
     issued by the Vendor.

C.   The Purchaser is willing to purchase the Assets from the Vendor and the
     Vendor is willing to sell the Assets to the Purchaser in accordance with
     the terms and conditions of this Agreement;

     NOW THEREFORE IN CONSIDERATION OF the mutual covenants and agreements
hereinafter set forth, and for other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the Parties hereto
covenant and agree as follows:


                                    ARTICLE I
                  DEFINITIONS AND PRINCIPLES OF INTERPRETATION

1.1  Definitions - Whenever used in this Agreement, the following words and
     terms shall have the respective meanings ascribed to them as follows:

     "Agreement" means this Asset Purchase and Sale Agreement, including any
     Schedules attached hereto, and all amendments made by written agreement
     between the Parties;

     "Assets" means those assets owned by the Vendor and listed in Schedule "A"
     attached hereto which shall include all type of service agreements, if any,
     warranties by producers, insurance policies, spare parts supplier
     agreements, if any, and any other agreements and governmental licenses
     required for the proper operation of the Assets;

     "Asset Lease Agreements" means those agreements listed in Schedule "D"
     attached hereto which are entered into by the Vendor and which may involve
     the use of some of the Assets on and after the Closing Date;

     "Business Day" means a day other than a Saturday, Sunday, or any other day
     on which the principal commercial banks located in McAllen, Texas are not
     open for business during normal banking hours;

     "Closing" means subject to the terms and conditions of this Agreement, the
     completion of the sale, assignment, transfer and conveyance by the Vendor
     to the Purchaser and the purchase and receipt by the Purchaser from the
     Vendor of the Assets, and the execution and delivery by the Parties of all
     documents, and the satisfaction of all conditions required for such
     transactions to be completed;

     "Closing Date" means May 4th, 2001 or such other date as the Parties may
     agree upon as the date upon which the Closing shall take place;

     "Employees" means those employees of the Vendor listed in Schedule "C"
     attached hereto;

     "Encumbrances" means mortgages, charges, pledges, security interests,
     liens, encumbrances, actions, claims, demands and equities of any nature
     whatsoever or howsoever arising and any rights or privileges capable of
     becoming any of the foregoing;

     "Excluded Assets" means any real property whether leased or owned by the
     Vendor, any leased or borrowed equipment, any cash, receivables and
     equivalents, any contracts or agreements, any intellectual property rights,
     trade names, any prepaid deposits, including any applicable equipment
     duties, notes and any accounts receivable, including Mexican sales tax
     receivable, collected, collectible or in any way associated with the
     business and operations of the Vendor;

     "Governmental Charges" means all taxes, customs, duties, certificates,
     rates, levies, assessments, reassessments and other charges associated or
     in connection with the Assets, including the process of having goods and/or
     equipment nationalized in the country of Mexico, together with all
     penalties, interest and fines with respect thereto, payable to any federal,
     provincial, state, municipal, local or other government or governmental
     agency, authority, board, bureau or commission, domestic or foreign;

     "Mexico" means the United Mexican States;


     "Parties" means the parties to this Agreement, collectively, and "Party"
     means any one of them;

     "Purchase Price" has the meaning set out in Section 2.1; and

     "Taxes" means all federal, state and local taxes, fiscal rights, duties and
     contributions, including, but not limited to, all payment obligations to
     the Instituto Mexicano del Seguro Social (IMSS), Instituto Nacional para el
     Fondo de la Vivienda de los Trabajadores (INFONAVIT), Sistema de Ahorro
     para el Retiro (SAR) payroll, withholding, excise, added value, social
     security, sales use real and personal property, asset tax, use and
     occupancy, business and occupation, real estate, capital stock, and
     franchise or other tax (including interest and penalties thereon and
     including estimated payment amounts thereof).

1.2  Schedules - The following are the Schedules annexed hereto and incorporated
     by reference and deemed to be part hereof:

                  Schedule "A"      -       Assets
                  Schedule "B"      -       Bill of Sale
                  Schedule "C"      -       Employees
                  Schedule "D"      -       Asset Lease Agreements

1.3  Entire Agreement - With the exception of a Letter Agreement dated May 4th,
     2001 made between the Purchaser, the Shareholder and the Vendor with
     respect to the employment status of the Employees, a Letter Agreement dated
     May 4th, 2001 made between the Purchaser, The Beard Company and Testco Inc.
     regarding the corporate tax status of the Vendor, and a Rental Agreement
     dated May 4th, 2001 made between the Purchaser and the Vendor regarding the
     rental of certain of the Assets for a period of time on and after the
     Closing Date, this Agreement constitutes the entire agreement between the
     Parties and supercedes all prior and contemporaneous agreements,
     understandings, negotiations and discussions, whether oral or written, of
     the Parties, and there are no warranties, representations and other
     agreements between the Parties in connection with the subject matter hereof
     except as specifically set forth in this Agreement.

1.4  Extended Meanings - In this Agreement, words importing the singular number
     include the plural and vice versa; words importing the masculine gender
     include the feminine and neuter genders.

1.5  References - References to an Article, Section, Subsection, Paragraph or
     Schedule shall be construed as references to an Article, Section,
     Subsection, Paragraph or Schedule to this Agreement unless the context
     otherwise requires.

1.6  Currency - Unless otherwise indicated, all dollar amounts referred to in
     this Agreement are in American (U.S.) dollars.

1.7  Governing Law - This Agreement shall be construed in accordance with the
     laws of Mexico and shall be treated, in all respects, as a Mexican
     contract.

1.8  Language of Agreement - This Agreement shall be written in both the English
     and Spanish languages. Should there be any discrepancy or conflict between
     the English language version and the Spanish language version of this
     Agreement, the language of the English version shall govern.


                                   ARTICLE II
                           SALE AND PURCHASE OF ASSETS

2.1  Purchase Price of the Assets - The Vendor shall sell to the Purchaser, and
     the Purchaser shall purchase from the Vendor, the Assets, which for greater
     certainty shall exclude the Excluded Assets and any applicable Mexican IVA
     taxes, for an aggregate purchase price of U.S. $885,672.00 (the "Purchase
     Price").

2.2  Payment of Purchase Price - The Purchaser shall pay the Vendor the Purchase
     Price in the following manner:

     (a)  On Closing, the Purchaser shall pay the Vendor by way of wire transfer
          U.S. $800,000.00 plus all applicable Mexican IVA taxes based on the
          total aggregate Purchase Price stated in Section 2.1 above;

     (b)  The Purchaser shall hold back a total of U.S. $85,672.00 from the
          payment of the Purchaser Price for a period of ninety (90) days from
          the Closing Date and subject to any issues of indemnification as set
          out in Article VI hereof, the Purchaser shall pay the Vendor the
          balance of any such hold back monies remaining, if any, by way of wire
          transfer in the following manner:
<TABLE>
<S>                                                                        <C>
          (i) on the expiry of thirty (30) days from the Closing Date:     U.S. $28,557.34
          (ii) on the expiry of sixty (60) days from the Closing Date:     U.S. $28,557.33
          (iii) on the expiry of ninety (90) days from the Closing Date:   U.S. $28,557.33
</TABLE>

     (c)  Where the Purchaser reduces its payment of any or all of the hold back
          money referred to in Subsection 2.2(b) above, the Purchaser shall
          provide to the Vendor written reasons for such reduction along with a
          proper accounting of such amounts, if possible.

2.3  Bill of Sale - On Closing, the Parties agree to execute a Bill of Sale with
     respect to the sale of the Assets in the form provided in Schedule "B"
     attached hereto which shall be in compliance with applicable Mexican tax
     laws.


                                   ARTICLE III
                         REPRESENTATIONS AND WARRANTIES

3.1  Representations and Warranties of the Vendor and the Shareholder - The
     Vendor and the Shareholder hereby represent and warrant to the Purchaser
     that as of the date of this Agreement:

     (a)  Organization and Good Standing of the Corporation - The Vendor is a
          corporation duly incorporated and organized and is validly existing
          under the laws of Mexico and has all necessary power, authority and
          capacity to own or otherwise hold the Assets and is in good standing
          and has conducted its business in accordance with applicable laws, the
          failure to comply with which would not have an adverse impact on the
          Vendor or its ability to convey the Assets to the Purchaser.

     (b)  Title to Assets - The Vendor is the owner of the Assets, free and
          clear of any Encumbrances, and as such is entitled to absolutely
          convey to the Purchaser at Closing all of its right, title and
          interest in the Assets.

     (c)  Corporate Authority and Binding Obligations - The Vendor has all
          necessary right and capacity, full corporate power and absolute
          authority to sign and deliver this Agreement, and to sell, assign and
          transfer the Assets in the manner contemplated in this Agreement, to
          perform its obligations under this Agreement, and to otherwise
          complete the transactions contemplated in this Agreement. The Vendor,
          its respective boards of directors, and its respective shareholders
          have taken all necessary or desirable actions, steps and corporate and
          other proceedings to approve or authorize, validly and effectively,
          the entering into, and the signing, delivery and performance of, this
          Agreement, sale, assignment and transfer of the Assets. The Vendor has
          conferred upon its legal representatives the necessary and sufficient
          powers and authority to sign and execute this Agreement on its behalf,
          which powers and authority have not been limited, modified or revoked
          in any manner whatsoever.

     (d)  Location of Assets - Both now and at Closing, all of the Assets are
          located in Mexico within a distance of approximately twenty (20) miles
          from Reynosa, Tamaulipas, Mexico.

     (e)  Use of the Assets - As of the Closing Date, the Assets shall be made
          available for the sole and immediate use by the Purchaser. For greater
          clarification as of the Closing Date, these are no lease agreements or
          other arrangements in place with any third party which may involve the
          use, operation or delivery of any of the Assets on or after the
          Closing Date except for those agreements stated in Schedule "D"
          attached hereto.

     (f)  Termination of Employees - As of the Closing Date, the Vendor will
          have properly terminated those Employees listed in Section A of
          Schedule "C" attached hereto in accordance with Mexican law and will
          have paid such Employees, in full, all earned wages, bonuses,
          benefits, severance, vacation pay, insurance and any other amounts
          owing to the Employees which have accrued in connection with their
          employment by the Vendor up to and including the Closing Date. Such
          termination payment shall not be, and is not part of the Purchase
          Price.

     (g)  Payment of Taxes - As of the Closing Date, the Vendor shall have
          properly filed and paid before the corresponding tax authorities all
          of the Taxes and tax returns which are due and payable by the Vendor
          prior to such Closing Date.

     (h)  All or Substantially all of the Assets of the Business of the Vendor -
          Excepting the Excluded Assets, the Assets consist of all of the assets
          of the Vendor which are set out in Schedule "A" attached hereto.

3.2  Representations and Warranties of the Purchaser - The Purchaser hereby
     represents and warrants to the Vendor and the Shareholder that as of the
     date of this Agreement:

     (a)  Organization and Good Standing of the Corporation - The Purchaser is a
          corporation duly incorporated and organized and is validly existing
          under the laws of Mexico.

     (b)  Corporate Authority and Binding Obligations - The Purchaser has all
          necessary right and capacity, full corporate power and absolute
          authority to sign and deliver this Agreement, and to purchase the
          Assets in the manner contemplated in this Agreement, to perform its
          obligations under this Agreement, and to otherwise complete the
          transactions contemplated in this Agreement. The Purchaser, its
          respective boards of directors, and its respective shareholders have
          taken all necessary or desirable actions, steps and corporate and
          other proceedings to approve or authorize, validly and effectively,
          the entering into, and the signing, delivery and performance of, this
          Agreement, sale, assignment and transfer of the Assets. It has
          conferred upon its legal representative the necessary and sufficient
          powers and authority to sign and execute this Agreement on its behalf,
          which powers and authority have not been limited, modified or revoked
          in any manner whatsoever.

3.3  Condition of the Assets - Subject to Sections 3.1, 4.1 and 6.1, the Parties
     agree that the Assets are to be purchased on an "as is-where is" basis and
     there are no collateral agreements, conditions, representations or
     warranties of any nature whatsoever made by the Vendor, express or implied,
     arising at law, by statute or in equity or otherwise, with respect to the
     quality and condition of the Assets.


                                   ARTICLE IV
                                    COVENANTS

4.1  Covenants of the Vendor and the Shareholder - The Vendor and the
     Shareholder covenant and agree with the Purchaser as follows:

     (a)  From the date of this Agreement up to and including the Closing Date,
          the Vendor shall keep the Assets in a safe and secure location in
          accordance with the representations made in this Agreement and in the
          same state of repair and condition as they were on the date of this
          Agreement or the date of last inspection by the Purchaser, whichever
          is earlier, usual wear and tear excepted, and the Vendor shall
          immediately inform the Purchaser if the condition or location of the
          Assets materially changes in any respect. Therefore, the Vendor shall
          have the duties and obligations as "Depositary" of the Assets,
          pursuant to the provisions contained for such purposes under the
          Federal Civil Code, until the Purchaser has full control and
          possession of the Assets.

     (b)  As of the Closing Date, the Vendor shall ensure that any and all
          Assets located in Mexico are certified by the applicable Mexican
          governmental authority as being "nationalized" as that term is
          understood and applied in such country with respect to the use and
          importation of goods and equipment into Mexico.

     (c)  Upon the completion of any Asset Lease Agreement listed in Schedule
          "D" attached hereto, the Vendor shall immediately terminate in
          accordance with Mexican law those applicable Employees listed in
          Section B of Schedule "C" attached hereto, and in connection with such
          termination, the Vendor shall pay such Employees, in full, all earned
          wages, bonuses, benefits, severance, vacation pay, insurance and any
          other amounts owing to such Employees which have accrued in connection
          with their employment by the Vendor up to and including the date of
          their termination. The Vendor acknowledges and agrees that such
          termination payment shall not be, and is not part of the Purchase
          Price.

     (d)  The Vendor will cooperate with the Purchaser in any and all respects
          so as to carry out the transactions contemplated by this Agreement in
          the most beneficial tax-effective manner available to the Purchaser,
          including determining an allocation of value with respect to the
          Assets and cooperating with the Purchaser in asserting the deemed
          value of the Assets, in case any Mexican taxing authority concludes
          that such values have not been properly determined.

     (e)  The Vendor shall properly collect and remit any applicable taxes
          associated with the purchase of the Assets by the Purchaser to the
          relevant governmental authority and in that regard will also arrange
          for the proper and timely filing of any applicable tax documents
          associated with such transaction.

     (f)  Within a term not to exceed thirty (30) days as from the Closing Date,
          the Vendor shall provide to the Purchaser for its review and approval
          prior to its filing before the applicable Mexican taxing authorities,
          any and all tax returns and any notices prepared as a result of the
          execution and performance of this Agreement.

     (g)  The Shareholders agree that they will not liquidate the Vendor within
          a period of one (1) year from the Closing Date.


                                    ARTICLE V
                              CLOSING ARRANGEMENTS

5.1  Closing - The Closing will take place on the Closing Date or on such other
     date that the Parties may agree. On Closing, the Parties shall arrange for
     the execution and delivery via facsimile, where applicable, of all such
     documents associated with such transaction. The Parties agree to arrange
     for the subsequent timely distribution and execution of original copies of
     such documents, where required, so that each Party shall have at least one
     set of original copies for its records.

5.2  Delivery of Documents by Vendor - The Vendor shall deliver to the Purchaser
     at Closing the following:

     (a)  evidence satisfactory to the Purchaser that all of the Assets located
          in Mexico at Closing are "nationalized", as that term is understood
          and applied in such country with respect to the use and importation of
          goods and equipment into Mexico;

     (b)  an executed copy of the Bill of Sale in the form provided in Schedule
          "B" attached hereto; and

     (c)  all other documents, instruments and writings required to be delivered
          by the Vendor pursuant to this Agreement or otherwise required in
          connection herewith, including but not limited to (i) warranties by
          producers; (ii) insurance policies; (iii) service agreements, if any;
          (iv) spare parts supplier agreements; (v) environmental permits and
          licenses, if any; (vi) import permits; (vii) evidence of import duties
          payments; (viii) evidence of payment of all Taxes which are due and
          payable by the Vendor at the Closing; and (ix) evidence of the
          complete termination of those applicable Employees at Closing.

5.3  Delivery of Documents by Purchaser - The Purchaser will deliver to the
     Vendor at Closing the following:

     (a)  an executed copy of the Bill of Sale in the form provided in Schedule
          "B" attached hereto;

     (b)  a wire transfer for that portion of the Purchase Price owing at
          Closing in accordance with Section 2.2(a) hereof; and

     (c)  all other documents, instruments and writings required to be delivered
          by the Purchaser pursuant to this Agreement or otherwise required in
          connection herewith.


                                   ARTICLE VI
                                 INDEMNIFICATION

6.1  Indemnity by Vendor and Shareholder- The Vendor and the Shareholder
     acknowledge and agree that they will jointly and severally indemnify and
     save the Purchaser harmless, at any time on or after the consummation of
     Closing, from and against any claims, demands, actions, cause of action,
     damage, loss, deficiency, cost, liability and expense which may be made or
     brought against the Purchaser or which the Purchaser may suffer or incur as
     a result of, in respect of or arising out of:

     (a)  any and all Governmental Charges incurred by the Purchaser with
          respect to "nationalizing" any Assets in Mexico as that term is
          understood and applied in such country with respect to the use and
          importation of goods and equipment into Mexico;

     (b)  any loss, damage, repair, theft or destruction of any of the Assets
          that arises prior to the Closing Date;

     (c)  any non-performance or non-fulfilment of any covenant or agreement on
          the part of the Vendor contained in this Agreement or in any document
          given in order to carry out the transactions contemplated hereby;

     (d)  any misrepresentation, inaccuracy, incorrectness or breach of any
          representation or warranty made by the Vendor contained in this
          Agreement or contained in any document or certificate given in order
          to carry out the transactions contemplated hereby;

     (e)  all costs and expenses including legal fees on a solicitor-and-client
          basis, incidental to or in respect of the foregoing;

     (f)  any Tax or related claim asserted against the Purchaser as a result of
          this Agreement or relating to the Assets with respect to any period
          ending on or prior to the Closing;

     (g)  any and all other Taxes which may be due as a result of the sale
          contemplated by this Agreement; and

     (h)  any and all liabilities, obligations or claims of or against the
          Purchaser as a result of, or arising from the labour relationships
          with the Employees.

6.2  Indemnity by Purchaser - The Purchaser acknowledges and agrees that it will
     indemnify and save the Vendor and the Shareholder harmless from and against
     any claims, demands, actions, cause of action, damage, loss, deficiency,
     cost, liability and expense which may be made or brought against the Vendor
     or which the Vendor may suffer or incur as a result of, in respect of or
     arising out of:

     (a)  any non-performance or non-fulfilment of any covenant or agreement on
          the part of the Purchaser contained in this Agreement or in any
          document given in order to carry out the transactions contemplated
          hereby;

     (b)  any misrepresentation, inaccuracy, incorrectness or breach of any
          representation or warranty made by the Purchaser contained in this
          Agreement or contained in any document or certificate given in order
          to carry out the transactions contemplated hereby; and

     (c)  all costs and expenses including legal fees on a solicitor-and-client
          basis, incidental to or in respect of the foregoing.

                                   ARTICLE VII
                                     GENERAL

7.1  Expenses - All costs and expenses (including, without limitation, the fees
     and disbursements of legal counsel) incurred in connection with this
     Agreement and the transactions contemplated hereby shall be paid by the
     Party incurring such expenses.

7.2  Risk - All risks of ownership of the Assets shall stay with the Vendor up
     to the Closing Date whereupon all such risk shall pass to the Purchaser on
     and after the Closing Date.

7.3  Time - Time shall be of the essence in this Agreement.

7.4  Notices - Any notice required or permitted to be given hereunder, or for
     the purposes hereof for any future payment to any Party, shall be
     sufficiently given if in writing and delivered personally, or in the case
     of written notice only, if transmitted by telecopier or other form of
     recorded communication to such Party:

     (a)  in the case of the Vendor and the Shareholder at:

          The Beard Company, Enterprise Plaza
          Suite 320, 5600 North May Avenue
          Oklahoma City, Oklahoma U.S.A.
                  73112

          Attention:        Herb Mee, Jr.
          Facsimile:        (405) 842-9901

     (b)  in the case of the Purchaser at:

          c/o Northland Energy Corporation
          4600, 150-6th Avenue S.W.
          Calgary, Alberta
          T2P 3Y7

          Attention:        Darwin Little, Senior Controller
          Facsimile:        (403) 206-2644

          with a copy to:

          Borden Ladner Gervais LLP
          Barristers and Solicitors
          1000 Canterra Tower
          400 - 3rd Avenue S.W.
          Calgary, AB, T2P 4H2

          Attention: Brian Roberts
          Facsimile: (403) 266-1395

          and a copy to:

          Lopez Velarde, Heftye Abogados
          Guilliermo Gonzalez Camarena No. 1600 - 6 piso
          Colonia Santa Fe, Centro de Ciudad
          01210 Mexico, D.F.

          Attention:       Rogelio Lopez-Velarde
          Facsimile:       (525) 081-1425

     or at such other address as the Party to whom such notice or payment is to
     be given shall have last notified to the Party giving the same in the
     manner provided in this Section. Any notice delivered to the Party to whom
     it is addressed shall be deemed to have been given and received on the day
     it is so delivered at such address, provided that if the notice is
     delivered after 4:00 p.m. (local time) or if such day is not a Business Day
     then the notice shall be deemed to have been given and received on the
     Business Day next following such day. Any notice transmitted by telecopier
     or other form of recorded communication shall be deemed given and received
     on the first Business Day after its transmission.

7.5  Assignment - This Agreement may not be assigned by either Party without the
     prior written consent of the other Party. Subject thereto, this Agreement
     shall enure to the benefit of and be binding upon the Parties and their
     respective successors and permitted assigns.

7.6  Further Assurances - The Parties shall provide all such reasonable
     assurances as may be required to consummate the transactions contemplated
     hereby, and each Party shall provide such further documents or instruments
     required by any other Party as may be reasonably necessary or desirable to
     effect the purpose of this Agreement and carry out its provisions, whether
     before or after the Closing.

7.7  Amendments - This Agreement may only be amended by agreement in writing
     signed by both Parties hereto.

7.8  Counterparts - This Agreement may be executed by the Parties in separate
     facsimile counterparts, each of which when so executed and delivered shall
     be an original, but all such counterparts shall together constitute one and
     the same instrument.

7.9  Severability - If any provision or section of this Agreement or the
     application thereof is held invalid under specified circumstances, the
     remainder of this Agreement or the application of such provision or section
     or part under other circumstances, shall not be affected thereby.


     IN WITNESS WHEREOF the Parties have duly executed this Agreement as of the
date first above written.

                                    TESTCO INC. de MEXICO, S.A. de C.V.


                                    Per:    NORBERT J. ROTHER
                                            Norbert J. Rother
                                            Attorney-in-Fact


                                    Per:    HERBERT M. MEE JR.
                                            Herbert M. Mee Jr.
                                            Attorney-in-Fact


                                    ITS-TESTCO, LLC
                                    Per its Manager:  Testco, Inc.


                                    Per:    NORBERT J. ROTHER
                                            Norbert J. Rother
                                            Attorney-in-Fact


                                    PD OILFIELD SERVICES MEXICANA, S. de R.L.
                                    de C.V.


                                    Per:    MICHAEL J. MCNULTY
                                            Michael J. McNulty
                                            Attorney-in-Fact


                                    Per:    JIM MCKIRAHAN
                                            Jim McKirahan
                                            Attorney-in-Fact

<PAGE>
                                  SCHEDULE "A"

                                     ASSETS

<PAGE>
                                  SCHEDULE "B"

                                  BILL OF SALE

<PAGE>
                                  SCHEDULE "C"

                                    EMPLOYEES


A.       Employees not associated with any Asset Lease Agreement

1.       Ayala Salinas, Javier
2.       Escalante Carreon, Ignacio
3.       Fuentes Segura Sergio, Alejandro
4.       Gomez Jasso Jose, Guadalupe
5.       Gutierrez Gonzalez, Gabriel
6.       Ugarte Castillo, Raul
7.       Rosales Chaves, Rodolfo
8.       Razo Aguilar Simon, Pedro
9.       Guajardo Gutierrez, Leona rdo
10.      Trevino Ibarra, Ruben
11.      Cantu Hernandez, Pablo
12.      Gomez Jasso Jose, Luis
13.      De la O Peral Ta, Eusebio
14.      Silvia Anabeth Cruz, Hernandez
15.      Tovar Mejia Luis, Andres
16.      Chavez Salazar Miguel, Angel
17.      Munoz Garcia, Fernando
18.      Acosta Ramirez Jose, Luis


B.       Employees associated with an Asset Lease Agreement

1.       Garcia Silva, Efren
2.       Arturo Aurelio Tellez, Leon
3.       Flores Noguera, Gustavo
4.       Sanchez Villanueva, Enrique
5.       Torres Torres Francisco, Javier
6.       Salomon Salinas de la Cruz

<PAGE>
                                  SCHEDULE "D"

                              ASSET LEASE AGREEMENT



Service Contract dated _______________, between Dowell Schlumberger de Mexico
S.A. de C.V. and Testco Inc. de Mexico S.A. de C.V.