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                                 TENTH AMENDMENT
                (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)

         This TENTH AMENDMENT dated as of December 13, 2001 (this "Amendment"),
to the Second Amended and Restated Credit Agreement, dated as of June 6, 1997,
as amended and restated through September 14, 1998, and as amended by the First
Amendment dated as of November 19, 1998, the Second Amendment dated as of
December 29, 1998, the Third Amendment dated as of April 8, 1999, the Fourth
Amendment dated as of April 15, 1999, the Fifth Amendment dated as of May 10,
1999, the Sixth Amendment dated as of July 14, 1999, the Seventh Amendment dated
as of March 1, 2000, the Eighth Amendment and Consent dated as of February 21,
2001 and the Ninth Amendment dated as of September 17, 2001 (the "Credit
Agreement"), among Key Energy Group, Inc. (now known as Key Energy Services,
Inc.), a Maryland corporation (the "Borrower"), the several Lenders from time to
time parties thereto, PNC Bank, National Association ("PNC"), as Administrative
Agent, Norwest Bank Texas, N.A., as Collateral Agent and PNC Capital Markets,
Inc., as Arranger.

                                    RECITALS

         A.       Borrower desires to obtain the right to issue additional
senior unsecured notes and to otherwise amend the Credit Agreement.

         B.       On November 19, 2001, the Borrower repurchased approximately
$21,400,000 of the 1997 Convertible Subordinated Notes (the "November 2001
Note Repurchase").

         C.       Borrower desires to obtain the right to consummate the
Senior Subordinated Notes Clawback (as defined herein) out of the proceeds of
the December 2001 Equity Issuance (as defined herein).

         D.       Borrower has asked Lenders to amend the Credit Agreement to
(1) accommodate the issuance of additional senior unsecured notes, (2)
accommodate the Senior Subordinated Notes Clawback, and (3) make other
requested modifications.

                  The parties hereto hereby agree as follows:

                  Section 1.    DEFINED TERMS. Unless otherwise defined
herein, terms which are defined in the Credit Agreement and used herein (and
in the recitals hereto) as defined terms are so used as so defined.

                  Section 2.    AMENDMENT TO SECTION 1.1 [DEFINED TERMS].
Section 1.1 of the Credit Agreement is hereby amended to add the following
definitions in the appropriate alphabetical order:

                           "'DECEMBER 2001 EQUITY ISSUANCE': the issuance by
                           the Borrower of its common stock during December

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                           2001 to one or more institutional investors or
                           investment bankers or in an underwritten public
                           offering.

                           "'FUTURE SENIOR NOTES INDENTURE': the indenture
                           pursuant to which the Borrower will issue the
                           Future Senior Notes which shall comply with the
                           requirements in Section 7.2(p).

                           "'FUTURE SENIOR NOTES': senior notes to be issued by
                           the Borrower in an aggregate principal amount not
                           to exceed $150,000,000, with a maturity of March 1,
                           2008 or later and with an interest rate not to
                           exceed 9.0%.

                           "'SENIOR SUBORDINATED NOTES CLAWBACK': the optional
                           redemption or purchase of approximately $35,400,000
                           principal amount of the Senior Subordinated Notes at
                           a redemption or purchase price of 114% of the
                           principal amount redeemed or repurchased.

                  Section 3.    AMENDMENT TO SECTION 4.22 [INDENTURES].
Section 4.22 of the Credit Agreement is hereby amended by adding the following
clause (d):

                  "(d) The Future Senior Notes and the Future Senior Notes
                  Indenture will contain terms substantially similar to those
                  applicable to the 2001 Senior Notes or other terms reasonably
                  acceptable to the Administrative Agent. All Obligations of the
                  Borrower and the other Loan Parties under this Agreement, the
                  Notes and the other Loan Documents will not conflict with or
                  violate the terms of the Future Senior Notes Indenture and any
                  Loans made or hereafter made to the Borrower will be (i)
                  indebtedness permitted to be incurred under the Future Senior
                  Notes Indenture and (ii) "Permitted Debt" under the provisions
                  of the Future Senior Notes Indenture which correspond to
                  clause (i) of the second paragraph of Section 4.09 of the 2001
                  Senior Notes Indenture (permitting indebtedness under "Credit
                  Facilities" up to $250,000,000). All obligations of the
                  Borrower and the other Loan Parties under the Future Senior
                  Notes Indenture and related documents will not conflict with
                  or violate the terms of the Credit Agreement."

                  Section 4.    AMENDMENT TO SECTION 7.1(c)
[CONSOLIDATED SENIOR LEVERAGE RATIO]. Section 7.1(c) of the Credit Agreement
is hereby amended and restated in its entirety as follows:

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                           "(c) Consolidated Senior Leverage Ratio. As of any
                           fiscal quarter end of the Borrower or as of any date
                           on which an interim computation of this covenant is
                           required under the terms of this Agreement, permit
                           the Consolidated Senior Leverage Ratio to exceed 2.75
                           to 1.00."

                  Section 5.    AMENDMENT TO SECTION 7.2 [LIMITATION ON
         INDEBTEDNESS]. Section 7.2 of the Credit Agreement is hereby amended by
         deleting the word "and" after the semicolon in paragraph (n), by
         deleting the "." at the end of paragraph (o) and replacing it with ";
         and", and by adding a new paragraph (p) as follows:

                           "(p) Indebtedness of Borrower and its Subsidiaries
                           under the Future Senior Notes, provided that prior to
                           the execution of the Future Senior Notes Indenture,
                           the Agent shall have received copies of such
                           indenture and all other documents governing the
                           Future Senior Notes Indenture and the Agent shall
                           have confirmed (such confirmation not to be
                           unreasonably withheld) that such indenture and
                           related documents contain terms substantially similar
                           to those applicable to the 2001 Senior Notes or
                           otherwise comply with Section 4.22; provided further,
                           that on the date of execution of the Future Senior
                           Notes Indenture and after giving effect to the
                           issuance of the Future Senior Notes (the amount of
                           which shall be included as Indebtedness in computing
                           the Consolidated Senior Leverage Ratio and other
                           covenants) the Borrower shall be in proforma
                           compliance with the covenants set forth in Section
                           7.1 of the Credit Agreement and the Borrower shall
                           promptly after such issuance, deliver to the Agent
                           and the Banks copies of the signed indenture and any
                           other documents requested by the Administrative
                           Agent."

                  Section 6.    AMENDMENT TO SECTION 7.4
[LIMITATION ON GUARANTEE OBLIGATIONS]. Section 7.4 of the Credit Agreement is
hereby amended by deleting the word "and" after the semicolon at the end of
paragraph (g), by deleting the "." at the end of paragraph (h) and replacing
it with "; and", and by adding a new paragraph (i) as follows:

                  "(i) Guarantee Obligations of the Subsidiaries of the Borrower
                  with respect to the Future Senior Notes."

                  Section 7.    AMENDMENT TO SECTION 7.5 [LIMITATION ON
FUNDAMENTAL CHANGES].

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Section 7.5 of the Credit Agreement is hereby amended by deleting the word
"and" after the semicolon at the end of paragraph (d), by deleting the "." at
the end of paragraph (e) and replacing it with "; and", and by adding a new
paragraph (f) as follows:

                  "(f) any merger or consolidation consummated in connection
                  with a Permitted Acquisition."

                  Section 8.    Amendment to Section 7.8 [Limitation on Capital
Expenditures]. The fourth line of the grid contained in Section 7.8 of the
Credit Agreement which currently reads: "2002         $65,000,000" is hereby
amended to read as follows:

                  "2002         $80,000,000"

                  Section 9. Amendment to Section 7.10 [Limitation on Optional
Payments and Modifications of Debt Instruments and Organizational Documentation
etc.]. Section 7.10 of the Credit Agreement is hereby amended by:

                  (a) amending and restating in its entirety clause (a) to read
                  as follows:

                  "(a) Make any optional payment or optional prepayment on or
                  redemption or purchase of any material Indebtedness (other
                  than the Loans) or preferred Capital Stock including, without
                  limitation, the Convertible Subordinated Debentures, the 1997
                  Convertible Subordinated Notes, the Put Facility, the Dawson
                  Notes, the Senior Subordinated Notes, the 2001 Senior Notes
                  and the Future Senior Notes," and

                  (b) amending and restating in its entirety clause (b)(i) to
                  read as follows:

                  "(i) the Put Facility (other than any such amendment,
                  modification or change to the terms of the Interim Loans such
                  that would satisfy in all respects the definition of `Senior
                  Subordinated Notes' contained in Section 1.1), the Senior
                  Subordinated Notes, the 2001 Senior Notes, the Future Senior
                  Notes or the Acquisition Documents without the consent of the
                  Required Lenders or", and

                  (c) deleting the last two sentences in the Section and
                  replacing it with the following:

                  "Notwithstanding anything to the contrary in this Section
                  7.10, the Borrower and any of its Subsidiaries may make or
                  cause to be made (i) the Senior Subordinated Notes Clawback;
                  provided, however, that the aggregate purchase price or
                  redemption price paid with respect to the Senior Subordinated
                  Notes purchased or redeemed in the Senior Subordinated Notes
                  Clawback shall not exceed the proceeds received by the Company
                  (after underwriting

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                  discounts) in connection with the December 2001 Equity
                  Issuance; and (ii) any other payment, prepayment,
                  redemption, repurchase or defeasance of any Indebtedness at
                  any time, if, after giving effect to such payment,
                  prepayment, redemption, repurchase or defeasance, (1)
                  Consolidated Liquidity equals or exceeds $25,000,000, (2) no
                  Default or Event of Default has occurred and is continuing,
                  and (3) the Borrower is in compliance with Section 7.1. In
                  addition, the Borrower may make or cause to be made any
                  payment, prepayment, redemption, repurchase or defeasance of
                  (1) the 2001 Senior Notes upon the occurrence of a "Change
                  of Control" under and as defined in the 2001 Senior Note
                  Indenture, or (2) the Future Senior Notes upon the
                  occurrence of a "Change of Control" under and as defined in
                  the Future Senior Notes Indenture."

                  Section 10.   AMENDMENT TO SECTION 7.14 [LIMITATION ON
NEGATIVE PLEDGE CLAUSES]. Section 7.14 of the Credit Agreement is hereby
amended by deleting the word "and" before "the 2001 Senior Notes" and
inserting a ",", and deleting the "." at the end of the Section and replacing
it with ", and (g) the Future Senior Notes."

                  Section 11.   CONDITIONS TO EFFECTIVENESS OF THIS AMENDMENT.
This Amendment shall become effective on the date on which the following
conditions have occurred (the "Effective Date"):

                  (a) the Administrative Agent shall have received a copy of
         this Amendment duly executed and delivered by a duly authorized officer
         of the Borrower, the Required Lenders and the Administrative Agent;

                  (b) the Administrative Agent shall have received the
         Acknowledgment and Consent, attached hereto as Exhibit A
         [Acknowledgment and Consent], executed and delivered by a duly
         authorized officer of each of the signatories thereto;

                  (c) no Default or Event of Default, other than those waived
         under this Amendment, shall exist and be continuing after giving effect
         to the November 2001 Note Repurchase; and

                  (d) the Administrative Agent shall have received such other
         corporate documents and resolutions as the Administrative Agent may
         reasonably request.

                  Section 13.   MISCELLANEOUS.

                  (a) NO DEFAULTS. The Borrower represents and warrants to the
         Administrative Agent and the Lenders that, by its execution and
         delivery hereof to the Administrative Agent, as of the Effective Date,
         after giving effect to this Amendment, and the November 2001 Note
         Repurchase, no Default or Event of Default has occurred and is
         continuing, and the representations and warranties made by the Borrower
         and the other

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         Loan Parties in or pursuant to the Credit Agreement or any Loan
         Documents are true and correct in all material respects on and as of
         the Effective Date as if made on such date (except to the extent that
         any such representations and warranties expressly relate to an
         earlier date, in which case such representations and warranties were
         true and correct in all material respects on and as of such earlier
         date).

                  (b) CONTINUING EFFECT OF THE CREDIT AGREEMENT. This Amendment
         shall not constitute an amendment or waiver of or consent to any
         provision of the Credit Agreement not expressly referred to herein and
         shall not be construed as an amendment, waiver or consent to any action
         on the part of the Borrower that would require an amendment, waiver or
         consent of the Agents or the Lenders except as expressly stated herein.
         Except as expressly consented to hereby, the provisions of the Credit
         Agreement and the other Loan Documents are and shall remain in full
         force and effect.

                  (c) FEES AND EXPENSES. The Borrower agrees to pay or reimburse
         the Administrative Agent on demand for all its reasonable out-of-pocket
         costs and expenses incurred in connection with the preparation and
         execution of this Amendment, including, without limitation, the
         reasonable fees and disbursements of counsel to the Administrative
         Agent.

                  (d) COUNTERPARTS. This Amendment may be executed in any number
         of counterparts (including by telecopy) by the parties hereto, each of
         which counterparts when so executed shall be an original, but all
         counterparts taken together shall constitute one and the same
         instrument.

                  (e) GOVERNING LAW. THIS AMENDMENT AND THE RIGHTS AND
         OBLIGATIONS OF THE PARTIES UNDER THIS AMENDMENT SHALL BE GOVERNED BY,
         AND CONSTRUED AND INTERPRETED IN ACCORDANCE WITH, THE LAW OF THE STATE
         OF NEW YORK.

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                    [SIGNATURE PAGE 1 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]

         IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
duly executed and delivered by their proper and duly authorized officers as of
the day and year first above written.


                                           KEY ENERGY SERVICES, INC. (formerly
                                           known as Key Energy Group, Inc.)



                                           By: /s/ THOMAS K. GRUNDMAN
                                           Title: Executive Vice President & CFO


                                           PNC BANK, NATIONAL ASSOCIATION,
                                           as Administrative Agent and as Lender



                                           By: /s/ RICHARD MUNSICK
                                           Title: Managing Director

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                    [SIGNATURE PAGE 2 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]


                                           BANK POLSKA KASA OPIEKI S.A.,
                                           PEKAO S.A. GROUP, NEW YORK
                                           BRANCH



                                           By:
                                           Title:

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                    [SIGNATURE PAGE 3 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]


                                           BANK LEUMI, USA



                                           By:
                                           Title:

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                    [SIGNATURE PAGE 4 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]


                                           BEAR STEARNS INVESTMENT
                                           PRODUCT INC.


                                           By:
                                           Title:



                                           BEAR STEARNS CORPORATE
                                           LENDING INC.


                                           By:
                                           Title:

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                    [SIGNATURE PAGE 5 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]


                                           ML CLO XV PILGRIM AMERICA
                                           (CAYMAN) LTD.
                                           By:  Pilgrim Investments, Inc.,
                                                as its Investment Manager


                                           By:
                                           Title:



                                           PILGRIM PRIME RATE TRUST
                                           By:  Pilgrim Investments, Inc.,
                                                as its Investment Manager]


                                           By:
                                           Title:

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                    [SIGNATURE PAGE 6 OF 6 TO TENTH AMENDMENT
               (TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT)]


                                           LEHMAN COMMERCIAL PAPER, INC.



                                           By: /s/ ROBERT CHAMBERS
                                           Title: Authorized Signatory

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                                    EXHIBIT A
                           ACKNOWLEDGMENT AND CONSENT

                           ACKNOWLEDGMENT AND CONSENT

                  Each of the undersigned corporations, as a guarantor under
that certain Amended and Restated Master Guarantee and Collateral Agreement,
dated as of June 6, 1997, as amended and restated through September 14, 1998 (as
amended, supplemented or otherwise modified from time to time, the "Guarantee"),
made by each of such corporations in favor of the Collateral Agent, acknowledges
the foregoing amendment and confirms and agrees that the Guarantee is, and shall
continue to be, in full force and effect and is hereby ratified and confirmed in
all respects and the Guarantee and all of the Collateral (as defined in the
Guarantee) do, and shall continue to, secure the payment of all of the
Obligations (as defined in the Guarantee) pursuant to the terms of the
Guarantee. Capitalized terms not otherwise defined herein shall have the
meanings assigned to them in the Credit Agreement referred to in the Amendment
to which this Acknowledgment and Consent is attached.

                                  YALE E. KEY, INC.
                                  KEY ENERGY DRILLING, INC.
                                  WELLTECH EASTERN, INC.
                                  ODESSA EXPLORATION INCORPORATED
                                  KALKASKA OILFIELD SERVICES, INC.
                                  WELL-CO OIL SERVICE, INC.
                                  PATRICK WELL SERVICE, INC.
                                  MOSLEY WELL SERVICE, INC.
                                  RAM OIL WELL SERVICE, INC.
                                  ROWLAND TRUCKING CO., INC.
                                  LANDMARK FISHING & RENTAL, INC.
                                  DUNBAR WELL SERVICE, INC.
                                  FRONTIER WELL SERVICE, INC.
                                  KEY ROCKY MOUNTAIN, INC.
                                  KEY FOUR CORNERS, INC.
                                  JETER SERVICE CO.
                                  JETER WELL SERVICE, INC.
                                  JETER TRANSPORTATION, INC.
                                  INDUSTRIAL OILFIELD SUPPLY, INC.
                                  BROOKS WELL SERVICING, INC.
                                  UPDIKE BROTHERS, INC.
                                  J.W. GIBSON WELL SERVICE COMPANY
                                  KEY ENERGY SERVICES-SOUTH TEXAS, INC.
                                  WATSON OILFIELD SERVICE & SUPPLY, INC.
                                  WELLTECH MID-CONTINENT, INC.
                                  DAWSON PRODUCTION MANAGEMENT, INC.
                                  DAWSON PRODUCTION ACQUISITION CORP.
                                  DAWSON PRODUCTION TAYLOR, INC.

<Page>

                                  KEY ENERGY SERVICES-CALIFORNIA, INC.


                                  By: /s/ THOMAS K. GRUNDMAN
                                  Title: Executive Vice President & CFO



                                  DAWSON PRODUCTION PARTNERS, L.P.
                                  By:   DAWSON PRODUCTION
                                        MANAGEMENT, INC.,
                                        its sole general partner


                                  By: /s/ THOMAS K. GRUNDMAN
                                  Title: Executive Vice President & CFO