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                                                                   EXHIBIT 4.18



                         REGISTRATION RIGHTS AGREEMENT


         This REGISTRATION RIGHTS AGREEMENT dated as of September 25, 1997 (this
"Agreement"), by and between UTI ENERGY CORP, a Delaware corporation (the
"Company"), and VAUGHN E. DRUM ("Mr. Drum").

                             W I T N E S S E T H :

         WHEREAS, the Company intends to file a Registration Statement on Form
S-3 (the "Registration Statement") with the Securities and Exchange Commission
(the "Commission") to register up to 2,580,842 shares (the "Shares") of the
Company's common stock, $.01 par value (the "Common Stock"), under the
Securities Act of 1933 (the "1933 Act"); and

         WHEREAS, in connection with the filing of the Registration Statement
to register the Shares, the Company intends to initiate an underwritten public
offering (the "Offering") of the Shares; and

         WHEREAS, subject to the terms and conditions hereof, the Company and
Mr. Drum have agreed to allow Mr. Drum to include up to 112,500 shares of
Common Stock in the Offering;

         NOW, THEREFORE, in consideration of the foregoing and the respective
covenants and agreements herein contained, the parties hereto agree as follows:


         SECTION 1.       PARTICIPATION IN REGISTRATION.

                 (a)      In addition to the Shares, the Company agrees,
subject to the provisions hereof, to include up to 112,500 shares of Common
Stock owned by Mr. Drum (the "Additional Shares") in the Registration Statement
(the filing of the Registration Statement to register the Shares and the
Additional Shares referred to as the "Registration").

                 (b)      The Additional Shares included for sale in the
Offering shall be on the same terms and conditions as the Shares to be
registered and sold through underwriters pursuant to the Registration
Statement; provided, however, that as a condition to the inclusion of the
Additional Shares, Mr. Drum shall execute an underwriting agreement acceptable
to the Company and the underwriters and, if requested, a custody agreement
having such customary terms as the underwriters shall request, including
indemnification, and if the managing underwriter determines and advises the
Company and Mr. Drum in writing that the inclusion in the Offering of all of
the Additional Shares and any other shares of Common Stock sought to be
registered
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by any other stockholder of the Company exercising rights comparable to those
of Mr. Drum under this Agreement (the "Other Common Stock") would, in its
reasonable and good faith judgment, interfere with the successful marketing of
the Shares to be registered for sale in the Offering by the Company, then the
number of Additional Shares and shares of Other Common Stock requested to be
included in the Offering shall be reduced pro rata among Mr. Drum and the
holders of Other Common Stock requesting inclusion in the Offering and may, in
the determination of such managing underwriter, be reduced to zero.

                 (c)      At any time prior to the filing of the Registration
Statement, the Company may terminate this Agreement if the Company determines
that it is not in the interests of the Company to pursue the Offering at such
time.  Nothing contained in this Agreement, however, shall limit the Company's
right to cancel, terminate, postpone or withdraw the Registration for any
reason.

         SECTION 2.       EXPENSES OF REGISTRATION. In connection with the
Registration, the Company will pay all (i) printing expenses, (ii) fees and
expenses of counsel for the Company and (iii) fees and expenses of accountants
for the Company. Mr. Drum will pay (i) all fees and expenses of his counsel,
(ii) all underwriting fees and discounts and brokerage and selling commissions
and (iii) his pro rata registration and filing fees and any fees and expenses
of underwriters' counsel relating to the registration, offering and sale of the
Additional Shares.

         SECTION 3.       INDEMNIFICATION.

                 (a)      In the event of the Registration of the Additional
Shares pursuant to this Agreement, the Company will indemnify and hold harmless
Mr. Drum within the meaning of Section 15 of the 1933 Act, against any losses,
claims, damages or liabilities, joint or several, to which Mr. Drum may become
subject under the 1933 Act or otherwise, insofar as such losses, claims,
damages or liabilities or actions in respect thereof arise out of or are based
upon any untrue statement or alleged untrue statement of any material fact
contained, on the effective date thereof, in the Registration Statement, the
final prospectus, or any amendment thereof or supplement thereto, including all
documents incorporated by reference therein, or arise out of or are based upon
the omission or alleged omission to state therein a material fact required to
be stated therein or necessary to make the statements therein not misleading,
and will reimburse Mr. Drum for any legal or any other expenses reasonably
incurred by them in connection with investigating or defending any such loss,
claim, damage, liability or action; provided, however, that the Company will
not be liable in any such case to the extent that any such loss, claim, damage
or liability arises out of or is based upon an untrue statement or alleged
untrue statement or omission or alleged omission made in the Registration
Statement, such final prospectus or such amendment or supplement, including all
documents incorporated by reference therein, in reliance upon and in conformity
with information furnished to the Company by or on behalf of Mr. Drum
specifically for use in the preparation thereof.





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                 (b)      In the event of the Registration of the Additional
Shares pursuant to this Agreement, Mr. Drum will indemnify and hold harmless
the Company and each person, if any, who controls the Company within the
meaning of Section 15 of the 1933 Act, each officer of the Company who signs
the Registration Statement, each director of the Company and each underwriter
and each person who controls any underwriter within the meaning of Section 15
of the 1933 Act, against any and all such losses, claims, damages, liabilities
or actions which the Company or such officer, director, underwriter or
controlling person may become subject under the 1933 Act or otherwise, and will
reimburse the Company, each such officer, director, underwriter and controlling
person for any legal or any other expenses reasonably incurred by such party in
connection with investigating or defending any such loss, claim, damage,
liability or action, to the extent and only to the extent (a) such loss, claim,
damage, liability or action in respect thereof arises out of or is based upon
any untrue statement or alleged untrue statement of any material fact contained
in the Registration Statement or any such prospectus, or any amendment thereof
or supplement thereto, or arises out of or is based upon the omission or
alleged omission to state therein a material fact required to be stated therein
or necessary to make the statements therein not misleading and (b) any such
statement or omission of a material fact was made in reliance upon and in
conformity with written information furnished to the Company by or on behalf of
Mr. Drum specifically for use in connection with the preparation of the
Registration Statement or prospectus. Mr. Drum also agrees to indemnify each
such underwriter and each person who controls any such underwriter within the
meaning of Section 15 of the 1933 Act as may reasonably and customarily be
requested by the underwriters in connection with the Offering.

                 (c)      Promptly after receipt by any indemnified person of
notice of any claim or commencement of any action in respect of which indemnity
is to be sought against an indemnifying person pursuant to this Agreement, such
indemnified person shall notify the indemnifying person in writing of such
claim or of the commencement of such action, and, subject to provisions
hereinafter stated, in case any such action shall be brought against an
indemnified person and such indemnifying person shall have been notified of the
same, such indemnifying person shall be entitled to participate therein, and,
to the extent it shall wish, to assume the defense thereof, with counsel
reasonably satisfactory to such indemnified person, and after notice from the
indemnifying person to such indemnified person of its election to assume the
defense thereof, such indemnifying person shall not be liable to such
indemnified person in connection with the defense thereof; provided, however,
if there exists or will exist a conflict of interest which would make it
inappropriate in the reasonable judgment of the indemnified person for the same
counsel to represent both the indemnified person and such indemnifying person
then such indemnified person shall be entitled to retain its own counsel at the
expense of such indemnifying person; provided further, however, the
indemnifying person shall not be required to pay for more than one separate
counsel for all of the indemnified persons in addition to any local counsel.





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         SECTION 4.       TRANSFER OF REGISTRATION RIGHTS. The rights granted
to Mr. Drum under this Agreement may not be assigned or transferred by Mr. Drum
to any other person.

         SECTION 5.       AMENDMENT, MODIFICATION AND WAIVER. This Agreement
may be amended with the consent of the Company and the Company may take any
action herein prohibited, or omit to perform any act herein required to be
performed by it, only if the Company shall have obtained the written consent to
such amendment, modification, action or omission to act, of Mr. Drum.

         SECTION 6.       ASSIGNMENT. This Agreement shall be binding upon and
inure to the benefit of and be enforceable by the parties hereto and, with
respect to the Company, its respective successors and assigns.

         SECTION 7.       GOVERNING LAW. This Agreement shall be construed in
accordance with and governed by the laws of the State of Texas, without regard
to the conflicts or choice of law rules of the State of Texas.

         SECTION 8.       NOTICES. Any notice, request, instruction or other
document to be given hereunder by any party hereto to any other party shall be
in writing and delivered personally, by facsimile (with receipt confirmed) or
by registered or certified mail, postage prepaid:

                 (a)      If to the Company, to:

                          UTI Energy Corp
                          16800 Greenspoint Park, Suite 225N
                          Houston, Texas 77060
                          Attention:       P. Blake Dupuis
                          Facsimile:       (281) 873-4141
                          Confirm:         (281) 873-4111

                          with copies to:

                          Fulbright & Jaworski L.L.P.
                          1301 McKinney, Suite 5100
                          Houston, Texas 77010-3095
                          Attention:       Curtis W. Huff
                          Facsimile:       (713) 651-5246
                          Confirm:         (713) 651-5151





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                 (b)      If to Mr. Drum, to:

                          Vaughn E. Drum
                          c/o UTI Energy Corp
                          16800 Greenspoint Park, Suite 225N
                          Houston, Texas 77060
                          Facsimile:       (281) 873-4141
                          Confirm:         (281) 873-4111

                 Any notice which is delivered personally in the manner
provided herein shall be deemed to have been duly given to the party to whom it
is directed upon actual receipt by such party (or its agent for notices
hereunder).  Any notice which is addressed and mailed in the manner herein
provided shall be conclusively presumed to have been duly given to the party to
which it is addressed at the close of business, local time of the recipient, on
the third day after the day it is so placed in the mail. Any notice which is
sent by facsimile shall be deemed to have been duly given to the party to which
it is addressed upon telephonic confirmation of the same as provided herein. A
copy of any notices delivered by facsimile shall promptly be mailed in the
manner herein provided to the party to which such notice was given.

         SECTION 9.       COUNTERPARTS. This Agreement may be executed in
separate counterparts, each of which will be deemed to be an original, but all
of which shall be considered one and the same instrument.





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         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed and delivered by their respective officers thereunto duly authorized
as of the date first above written.

                                        UTI ENERGY CORP



                                        By /s/ P. Blake Dupuis 
                                          -------------------------------
                                              P. Blake Dupuis
                                           Chief Financial Officer


                                        VAUGHN E. DRUM



                                        By /s/ Vaughn E. Drum 
                                          -------------------------------
                                              Vaughn E. Drum





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