<PAGE>   1
As filed with the Securities and Exchange Commission on May 8, 2001
                                                       Registration No. [______]

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   ----------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

                           --------------------------
                           PATTERSON-UTI ENERGY, INC.
             (Exact name of registrant as specified in its charter)

               Delaware                                          75-2504748
    (State or other jurisdiction of                           (I.R.S. Employer
     incorporation or organization)                          Identification No.)

   4510 Lamesa Highway, Snyder, Texas                               79549
(Address of Principal Executive Offices)                         (Zip Code)

                                   ----------

                              AMENDED AND RESTATED
                UTI ENERGY CORP. 1996 EMPLOYEE STOCK OPTION PLAN
                                       and
AMENDED AND RESTATED NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN OF UTI ENERGY CORP.
                           (Full title of the plan(s))

                                   ----------

                                Cloyce A. Talbott
                             Chief Executive Officer
                           Patterson-UTI Energy, Inc.
                    4510 Lamesa Highway, Snyder, Texas 79549
                                 (915) 573-1104
            (Name, address and telephone number of agent for service)

                                   Copies to:

<TABLE>
<S>                                                                             <C>
         Jonathan D. Nelson                                                     Thomas H. Maxfield, Esq.
         Chief Financial Officer and Vice President - Finance                   Baker & Hostetler LLP
         4510 Lamesa Highway                                                    303 East Seventeenth Avenue
         Snyder, Texas  79549                                                   Suite 1100
                                                                                Denver, Colorado  80203
</TABLE>
                                   ----------

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
==================================================================================================
                                       Proposed maximum    Proposed maximum
Title of securities    Amount to be     offering price    aggregate offering       Amount of
to be registered       registered(1)     per share(2)          price(2)        registration fee(2)
--------------------   -------------   ----------------   ------------------   -------------------
<S>                    <C>             <C>                <C>                  <C>
Common Stock, par
value $.01 per share      1,225,300         $32.875           $9,251,013            $2,312.75
==================================================================================================
</TABLE>

(1)      The number of shares of common stock, par value $.01 per share, stated
         above ("Common Stock") consists of the aggregate number of shares which
         may be issued upon exercise of options previously granted under the
         Amended and Restated UTI Energy Corp. 1996 Employee Stock

<PAGE>   2
         Option Plan ("Employee Plan") and the Amended and Restated Non-Employee
         Director Stock Option Plan of UTI Energy Corp. ("Non-Employee Plan")
         (collectively, the "Plans"). The maximum number of shares which may be
         sold upon exercise of options granted under the Plans are subject to
         (i) adjustment in accordance with the anti-dilution and other
         provisions of the Plans ("Plan Provisions"); and (ii) the Stockholder
         Rights Plan dated January 2, 1997 between Patterson Energy, Inc. and
         Continental Stock Transfer & Trust Company, as rights agent ("Rights
         Agreement"). Accordingly, pursuant to Rule 416 promulgated under the
         Securities Act of 1933, as amended ("Securities Act"), this
         Registration Statement covers, in addition to the number of shares
         stated above, an indeterminate number of shares which may be subject to
         grant or otherwise issuable after the operation of any Plan Provision
         and/or the Rights Agreement.

(2)      Calculated pursuant to Rule 457(h), based upon the exercise price of
         outstanding options granted pursuant to the Plans. The exercise prices
         for the Common Stock underlying the options granted range from $3.65625
         to $32.875 per share of Common Stock.


<PAGE>   3

                                EXPLANATORY NOTE

         Patterson-UTI Energy, Inc. ("Registrant") hereby files this
Registration Statement on Form S-8 relating to its Common Stock issuable upon
the exercise of options granted under the Plans.

         Pursuant to the merger described in the Agreement and Plan of Merger
between Patterson Energy, Inc. and UTI Energy Corp. dated as of February 4, 2001
("Merger Agreement"), UTI Energy Corp. ("UTI") merged with and into Patterson
Energy, Inc. ("Patterson"), with Patterson as the surviving corporation under
the name "Patterson-UTI Energy, Inc." ("Merger"). Under the Merger Agreement,
the Registrant assumes the obligations of UTI under the Plans and each option to
purchase or acquire whole shares of UTI common stock granted under the Plans and
outstanding immediately prior to the effective time of the Merger ("UTI Stock
Option") becomes an option to purchase or acquire an equal number of shares of
the Registrant's Common Stock ("Substituted Option"). The Substituted Options
are exercisable upon the same terms and conditions applied to the UTI Stock
Options before the effective time of the Merger, after giving effect to any
existing provisions under the Plans that provide for the automatic acceleration
of vesting upon a change of control of UTI.

         This Registration Statement relates solely to the Common Stock of the
Registrant issuable upon exercise of the Substituted Options pursuant to the
Plans as follows:

         -        1,075,300 shares of Common Stock subject to the Employee Plan;
                  and

         -        150,000 shares of Common Stock subject to the Non-Employee
                  Plan.


                                       1
<PAGE>   4


                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

         The document(s) containing the information required by Part I will be
sent or given to employees as specified by Rule 428(b). Such documents are not
being filed with the Securities & Exchange Commission ("Commission") either as
part of this Registration Statement or as prospectuses or prospectus supplements
pursuant to Rule 424. Such documents and the documents incorporated by reference
in this Registration Statement pursuant to Item 3 of Part II to this Form S-8,
taken together, constitute a prospectus that meets the requirements of Section
10(a) of the Securities Act.


                                       I-1
<PAGE>   5


                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         All documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), subsequent to the date of the filing of this Registration
Statement and prior to the filing of a post-effective amendment that indicates
that all securities registered hereunder have been sold, or that deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of the filing of such documents. The documents listed in (a) through (i) below
are incorporated by reference in this Registration Statement.

         (a)      The Annual Report on Form 10-K of the Registrant for the
                  fiscal year ended December 31, 2000, filed with the Commission
                  on March 2, 2001;

         (b)      Patterson's Quarterly Report on Form 10-Q for the quarter
                  ended March 31, 2001, filed with the Commission on
                  May 7, 2001;

         (c)      Patterson's Current Report on Form 8-K dated February 5, 2001
                  and filed with the Commission on February 6, 2001;

         (d)      Patterson's Current Report on Form 8-K dated February 4, 2001
                  and filed with the Commission on February 16, 2001;

         (e)      Patterson's Current Report on Form 8-K dated March 27, 2001
                  and filed with the Commission on March 27, 2001;

         (f)      Patterson's Current Report on Form 8-K dated April 19, 2001
                  and filed with the Commission on April 23, 2001;

         (g)      Patterson's Current Report on Form 8-K filed with the
                  Commission on May 8, 2001;

         (h)      All other reports filed by the Registrant or Patterson with
                  the Commission pursuant to Section 13(a) or 15(d) of the
                  Exchange Act since December 31, 2000; and

         (i)      The description of the Registrant's Common Stock contained in
                  the Registrant's Registration Statement on Form 8-A, which
                  became effective with the Commission on November 2, 1993.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not Applicable.


                                      II-1
<PAGE>   6


ITEM 5.  INTEREST OF NAMED EXPERTS AND COUNSEL.

         The validity of the shares of the Registrant's Common Stock offered
hereby are being passed upon for the Registrant by Baker & Hostetler, LLP,
counsel to the Registrant. Members of that firm currently own 7,000 shares of
the Registrant's common stock.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         The Delaware General Corporation Law ("DGCL") allows a corporation to
indemnify directors, officers, employees and agents for costs and expenses
incurred by or in connection with an action, suit or proceeding brought by
reason of their position as a director, officer, employee or agent. The person
indemnified must have acted in good faith and in a manner he reasonably believed
to be in or not opposed to the best interests of the corporation. The DGCL
provides that a corporation may advance payment of expenses under certain
circumstances. The DGCL further provides that the indemnification and
advancement of expenses provisions of the DGCL will not be deemed exclusive of
any other rights of indemnification or advancement of expenses to which
directors, officers, employees and agents may be entitled under bylaw,
agreement, vote of stockholders or disinterested directors or otherwise, both as
to action in such person's official capacity and as to action in another
capacity while holding such office.

         In addition to the general indemnification section, Delaware law
provides further protection for directors under Section 102(b)(7) of the DGCL.
This section allows a Delaware corporation to include in its certificate of
incorporation a provision that eliminates or limits the personal liability of a
director for monetary damages for breaches of the director's fiduciary duty of
care, provided that any such provision does not (in the words of the statute) do
any of the following:

         "eliminate or limit the liability of a director (i) for any breach of
         the director's duty of loyalty to the corporation or its stockholders,
         (ii) for acts or omissions not in good faith or which involve
         intentional misconduct or a knowing violation of law, (iii) under
         Section 174 of this Title [dealing with willful or negligent violation
         of the statutory provision concerning dividends and stock purchases and
         redemptions], or (iv) for any transaction from which the director
         derived an improper personal benefit. No such provision shall eliminate
         or limit the liability of a director for any act or omission occurring
         prior to the date when such provision becomes effective...."

         The DGCL further empowers the board of directors of the Registrant to
make other indemnification as authorized under the provisions of the restated
certificate of incorporation or bylaws, corporate resolution or agreement so
long as the indemnification is consistent with the DGCL.

         The Registrant's restated certificate of incorporation provides that,
to the fullest extent permitted by the DGCL, a director of the Registrant will
not be liable to the Registrant or its stockholders for monetary damages for
breach of fiduciary duty as a director. The Registrant's bylaws provide that to
the extent that a director, officer, employee or agent of the Registrant is
successful on the merits of defense of a suit or proceeding brought against him
by reason of his position within the Registrant, he shall be indemnified against
expenses (including attorneys'


                                      II-2
<PAGE>   7


fees) actually and reasonably incurred in connection with such action. In other
circumstances, a director, officer employee or agent of the Registrant may be
indemnified against expenses (including attorneys' fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by him in connection
with such action, suit or proceeding if he acted in good faith and in a manner
he reasonably believed to be in and not opposed to the best interest of the
Registrant, and, with respect to a criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful; however, in an action or
suit by or in the right of the Registrant to procure a judgment in its favor,
such person will not be indemnified if he has been adjudged to be liable to the
Registrant unless and only to the extent that the Delaware Court of Chancery or
the court in which such action or suit was brought determines upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the Court of Chancery or such other court deems proper. A
determination that indemnification is proper will be made by a majority of the
Registrant's disinterested directors, by independent legal counsel or by the
stockholders of the Registrant. The Registrant's bylaws also provide that the
Registrant may advance the payment of expenses and that the indemnification and
advancement of expense provisions of the bylaws are nonexclusive. The Registrant
maintains director and officer liability insurance covering director and officer
indemnification.

         In addition, the Merger Agreement provides that the Registrant will
indemnify the former officers and directors of UTI from liabilities arising out
of actions or omissions in their capacity as such prior to the effective time of
the Merger, and advance reasonable litigation expenses incurred in connection
with such actions or omissions, to the full extent permitted under UTI's
certificate of incorporation and bylaws. In addition, for a period of six years
after the effective time of the Merger, the Registrant will provide UTI's
officers and directors with an insurance and indemnification policy that
provides coverage through the effective time of the Merger; provided that the
maximum aggregate amount of premiums that the Registrant will be required to pay
to provide and maintain this coverage does not exceed $300,000 per year.


ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable.

ITEM 8.  EXHIBITS.

         The Exhibits listed in the accompanying Exhibit Index are filed or
incorporated by reference as part of this Registration Statement.

ITEM 9.  UNDERTAKINGS.

A.       The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement: (i) to include any
prospectus required by Section 10(a)(3) of the Securities Act; (ii) to reflect
in the prospectus any facts or events arising after the effective date of the
registration statement (or the most recent post-effective amendment thereof)
which, individually or in the aggregate, represent a fundamental change in the
information set


                                      II-3
<PAGE>   8


forth in the registration statement. Notwithstanding the foregoing, any decrease
or increase in volume of securities offered (if the total dollar value of the
securities offered would not exceed that which was registered) and any deviation
from the low or the high end of the estimated maximum offering range may be
reflected in the form of a prospectus filed with the Commission pursuant to Rule
424(b) if, in the aggregate, the changes in volume and price represent no more
than a 20% change in the maximum aggregate offering price set forth in the
"Calculation of Registration Fee" table in this Registration Statement; and
(iii) to include any material information with respect to the plan of
distribution not previously disclosed in the registration statement or any
material change to such information in the registration statement; provided,
however, that clauses (i) and (ii) do not apply if the information required to
be included in a post-effective amendment by those clauses is contained in
periodic reports filed with or furnished to the Commission by the Registrant
pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934,
as amended ("Exchange Act") that are incorporated by reference in this
Registration Statement;

         (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered that remain unsold at the termination of
the offering.

B.       The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

C.       Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the provisions described under Item 6 above or otherwise,
the Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.


                                      II-4
<PAGE>   9


                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Houston, State of Texas, on the 8th day of May, 2001.


                                                PATTERSON-UTI ENERGY, INC.



                                                By:  /s/ CLOYCE A. TALBOTT
                                                    -----------------------
                                                    Cloyce A. Talbott
                                                    Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Cloyce A. Talbott and A. Glenn Patterson,
or either of them, severally, as his/her attorney-in-fact and agent, with full
power of substitution and resubstitution, for him/her and in his/her name,
place, and stead, in any and all capacities, to sign any and all post-effective
amendments to this Registration Statement, and to file the same with all
exhibits hereto, and all other documents in connection herewith, with the
Commission, granting unto said attorney-in-fact and agent, and either of them,
full power and authority to do and perform each and every act and thing
requisite or necessary to be done in and about the premises, as fully to all
intents and purposes as he/she might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or either of them, or
their or his substitutes, may lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities indicated
on the 8th day of May, 2001.

<TABLE>
<CAPTION>
            SIGNATURE                                TITLE
            ---------                                -----
<S>                                <C>
    /s/ CLOYCE A. TALBOTT          Chief Executive Officer, Director (principal
--------------------------         executive officer)
    Cloyce A. Talbott

    /s/ JONATHAN D. NELSON         Vice President-Finance, Chief Financial Officer,
--------------------------         Secretary, Treasurer (principal financial
   Jonathan D. Nelson              officer and principal accounting officer)


    /s/ MARK S. SIEGEL             Chairman of the Board, Director
--------------------------
     Mark S. Siegel

    /s/ A. GLENN PATTERSON
--------------------------
    A. Glenn Patterson             President, Chief Operating Officer, Director
</TABLE>


                                      II-5
<PAGE>   10


<TABLE>
<S> /s/ SPENCER D. ARMOUR, III          <C>
------------------------------
   Spencer D. Armour, III          Director


    /s/ KENNETH N. BERNS
------------------------------
     Kenneth N. Berns              Director

    /s/ STEPHEN J. DeGROAT
------------------------------
    Stephen J. DeGroat             Director

    /s/ VAUGHN E. DRUM
------------------------------
     Vaughn E. Drum                Director

    /s/ ROBERT C. GIST
------------------------------
     Robert C. Gist                Director

    /s/ CURTIS W. HUFF
------------------------------
      Curtis W. Huff               Director

    /s/ KENNETH R. PEAK
------------------------------
     Kenneth R. Peak               Director

    /s/ NADINE C. SMITH
------------------------------
     Nadine C. Smith               Director
</TABLE>


                                      II-6


<PAGE>   11


                                  EXHIBIT INDEX


<TABLE>
<CAPTION>
        EXHIBIT
        NUMBER                  EXHIBIT DESCRIPTION
        -------                 -------------------
<S>             <C>
         4.1      Restated Certificate of Incorporation(1)

         4.2      Bylaws(2)

         4.3      Stockholder Rights Plan dated January 2, 1997 between
                  Patterson Energy, Inc. and Continental Stock Transfer & Trust
                  Company, as rights agent(3)

         4.4      Amended and Restated UTI Energy Corp. 1996 Employee Stock
                  Option Plan

         4.5      Amended and Restated Non-Employee Director Stock Option Plan
                  of UTI Energy Corp.

         5.1      Opinion of Baker & Hostetler LLP

        15.1      Awareness Letter of PricewaterhouseCoopers LLP

        23.1      Consent of Independent Accountants, PricewaterhouseCoopers LLP

        23.2      Consent of M. Brian Wallace, Independent Petroleum Engineer

        23.3      Consent of Baker & Hostetler LLP(4)

        24.1      Power of Attorney(5)
</TABLE>


(1)      Incorporated herein by reference to Item 7, "Financial Statements and
         Exhibits" to Current Report on Form 8-K; filed with the Commission on
         May 8, 2001.

(2)      Incorporated herein by reference to Item 27, "Exhibits" to Amendment
         No. 2 to Registration Statement on Form SB-2 (File No. 33-68058-FW);
         filed October 28, 1993.

(3)      Incorporated herein by reference to Item 2, "Exhibits" to Registration
         Statement on Form 8-A; filed January 14, 1997.

(4)      Included in Opinion of Baker & Hostetler, LLP; filed as Exhibit 5.1.

(5)      Included in the signature page to this Registration Statement.
[{"type": "S-8", "sequence": "1", "filename": "d86833s-8.txt", "description": "FORM S-8", "secsgml_size_bytes": 26200}]
{"company-data": {"conformed-name": "PATTERSON UTI ENERGY INC", "cik": "0000889900", "assigned-sic": "1381", "irs-number": "752504748", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-60466", "film-number": "1625999"}, "business-address": {"street1": "4510 LAMESA HWY", "street2": "P O DRAWER 1416", "city": "SNYDER", "state": "TX", "zip": "79549", "phone": "9155731104"}, "mail-address": {"street1": "P O DRAWER 1416", "city": "SNYDER", "state": "TX", "zip": "79550"}, "former-company": {"former-conformed-name": "PATTERSON ENERGY INC", "date-changed": "19940228"}}
1
As filed with the Securities and Exchange Commission on May 8, 2001
                                                       Registration No. [______]

================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                   ----------
                                    FORM S-8
                             REGISTRATION STATEMENT
                                      Under
                           The Securities Act of 1933

                           --------------------------
                           PATTERSON-UTI ENERGY, INC.
             (Exact name of registrant as specified in its charter)

               Delaware                                          75-2504748
    (State or other jurisdiction of                           (I.R.S. Employer
     incorporation or organization)                          Identification No.)

   4510 Lamesa Highway, Snyder, Texas                               79549
(Address of Principal Executive Offices)                         (Zip Code)

                                   ----------

                              AMENDED AND RESTATED
                UTI ENERGY CORP. 1996 EMPLOYEE STOCK OPTION PLAN
                                       and
AMENDED AND RESTATED NON-EMPLOYEE DIRECTOR STOCK OPTION PLAN OF UTI ENERGY CORP.
                           (Full title of the plan(s))

                                   ----------

                                Cloyce A. Talbott
                             Chief Executive Officer
                           Patterson-UTI Energy, Inc.
                    4510 Lamesa Highway, Snyder, Texas 79549
                                 (915) 573-1104
            (Name, address and telephone number of agent for service)

                                   Copies to:
Jonathan D. Nelson                                                     Thomas H. Maxfield, Esq.
         Chief Financial Officer and Vice President - Finance                   Baker & Hostetler LLP
         4510 Lamesa Highway                                                    303 East Seventeenth Avenue
         Snyder, Texas  79549                                                   Suite 1100
                                                                                Denver, Colorado  80203
----------

                         CALCULATION OF REGISTRATION FEE
==================================================================================================
                                       Proposed maximum    Proposed maximum
Title of securities    Amount to be     offering price    aggregate offering       Amount of
to be registered       registered(1)     per share(2)          price(2)        registration fee(2)
--------------------   -------------   ----------------   ------------------   -------------------
Common Stock, par
value $.01 per share      1,225,300         $32.875           $9,251,013            $2,312.75
==================================================================================================
(1)      The number of shares of common stock, par value $.01 per share, stated
         above ("Common Stock") consists of the aggregate number of shares which
         may be issued upon exercise of options previously granted under the
         Amended and Restated UTI Energy Corp. 1996 Employee Stock
2
         Option Plan ("Employee Plan") and the Amended and Restated Non-Employee
         Director Stock Option Plan of UTI Energy Corp. ("Non-Employee Plan")
         (collectively, the "Plans"). The maximum number of shares which may be
         sold upon exercise of options granted under the Plans are subject to
         (i) adjustment in accordance with the anti-dilution and other
         provisions of the Plans ("Plan Provisions"); and (ii) the Stockholder
         Rights Plan dated January 2, 1997 between Patterson Energy, Inc. and
         Continental Stock Transfer & Trust Company, as rights agent ("Rights
         Agreement"). Accordingly, pursuant to Rule 416 promulgated under the
         Securities Act of 1933, as amended ("Securities Act"), this
         Registration Statement covers, in addition to the number of shares
         stated above, an indeterminate number of shares which may be subject to
         grant or otherwise issuable after the operation of any Plan Provision
         and/or the Rights Agreement.

(2)      Calculated pursuant to Rule 457(h), based upon the exercise price of
         outstanding options granted pursuant to the Plans. The exercise prices
         for the Common Stock underlying the options granted range from $3.65625
         to $32.875 per share of Common Stock.
3

                                EXPLANATORY NOTE

         Patterson-UTI Energy, Inc. ("Registrant") hereby files this
Registration Statement on Form S-8 relating to its Common Stock issuable upon
the exercise of options granted under the Plans.

         Pursuant to the merger described in the Agreement and Plan of Merger
between Patterson Energy, Inc. and UTI Energy Corp. dated as of February 4, 2001
("Merger Agreement"), UTI Energy Corp. ("UTI") merged with and into Patterson
Energy, Inc. ("Patterson"), with Patterson as the surviving corporation under
the name "Patterson-UTI Energy, Inc." ("Merger"). Under the Merger Agreement,
the Registrant assumes the obligations of UTI under the Plans and each option to
purchase or acquire whole shares of UTI common stock granted under the Plans and
outstanding immediately prior to the effective time of the Merger ("UTI Stock
Option") becomes an option to purchase or acquire an equal number of shares of
the Registrant's Common Stock ("Substituted Option"). The Substituted Options
are exercisable upon the same terms and conditions applied to the UTI Stock
Options before the effective time of the Merger, after giving effect to any
existing provisions under the Plans that provide for the automatic acceleration
of vesting upon a change of control of UTI.

         This Registration Statement relates solely to the Common Stock of the
Registrant issuable upon exercise of the Substituted Options pursuant to the
Plans as follows:

         -        1,075,300 shares of Common Stock subject to the Employee Plan;
                  and

         -        150,000 shares of Common Stock subject to the Non-Employee
                  Plan.

                                       1
4

                                     PART I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

         The document(s) containing the information required by Part I will be
sent or given to employees as specified by Rule 428(b). Such documents are not
being filed with the Securities & Exchange Commission ("Commission") either as
part of this Registration Statement or as prospectuses or prospectus supplements
pursuant to Rule 424. Such documents and the documents incorporated by reference
in this Registration Statement pursuant to Item 3 of Part II to this Form S-8,
taken together, constitute a prospectus that meets the requirements of Section
10(a) of the Securities Act.

                                       I-1
5

                                     PART II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

ITEM 3.  INCORPORATION OF DOCUMENTS BY REFERENCE.

         All documents filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), subsequent to the date of the filing of this Registration
Statement and prior to the filing of a post-effective amendment that indicates
that all securities registered hereunder have been sold, or that deregisters all
securities then remaining unsold, shall be deemed to be incorporated by
reference in this Registration Statement and to be a part hereof from the date
of the filing of such documents. The documents listed in (a) through (i) below
are incorporated by reference in this Registration Statement.

         (a)      The Annual Report on Form 10-K of the Registrant for the
                  fiscal year ended December 31, 2000, filed with the Commission
                  on March 2, 2001;

         (b)      Patterson's Quarterly Report on Form 10-Q for the quarter
                  ended March 31, 2001, filed with the Commission on
                  May 7, 2001;

         (c)      Patterson's Current Report on Form 8-K dated February 5, 2001
                  and filed with the Commission on February 6, 2001;

         (d)      Patterson's Current Report on Form 8-K dated February 4, 2001
                  and filed with the Commission on February 16, 2001;

         (e)      Patterson's Current Report on Form 8-K dated March 27, 2001
                  and filed with the Commission on March 27, 2001;

         (f)      Patterson's Current Report on Form 8-K dated April 19, 2001
                  and filed with the Commission on April 23, 2001;

         (g)      Patterson's Current Report on Form 8-K filed with the
                  Commission on May 8, 2001;

         (h)      All other reports filed by the Registrant or Patterson with
                  the Commission pursuant to Section 13(a) or 15(d) of the
                  Exchange Act since December 31, 2000; and

         (i)      The description of the Registrant's Common Stock contained in
                  the Registrant's Registration Statement on Form 8-A, which
                  became effective with the Commission on November 2, 1993.

ITEM 4.  DESCRIPTION OF SECURITIES.

         Not Applicable.

                                      II-1
6

ITEM 5.  INTEREST OF NAMED EXPERTS AND COUNSEL.

         The validity of the shares of the Registrant's Common Stock offered
hereby are being passed upon for the Registrant by Baker & Hostetler, LLP,
counsel to the Registrant. Members of that firm currently own 7,000 shares of
the Registrant's common stock.

ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.

         The Delaware General Corporation Law ("DGCL") allows a corporation to
indemnify directors, officers, employees and agents for costs and expenses
incurred by or in connection with an action, suit or proceeding brought by
reason of their position as a director, officer, employee or agent. The person
indemnified must have acted in good faith and in a manner he reasonably believed
to be in or not opposed to the best interests of the corporation. The DGCL
provides that a corporation may advance payment of expenses under certain
circumstances. The DGCL further provides that the indemnification and
advancement of expenses provisions of the DGCL will not be deemed exclusive of
any other rights of indemnification or advancement of expenses to which
directors, officers, employees and agents may be entitled under bylaw,
agreement, vote of stockholders or disinterested directors or otherwise, both as
to action in such person's official capacity and as to action in another
capacity while holding such office.

         In addition to the general indemnification section, Delaware law
provides further protection for directors under Section 102(b)(7) of the DGCL.
This section allows a Delaware corporation to include in its certificate of
incorporation a provision that eliminates or limits the personal liability of a
director for monetary damages for breaches of the director's fiduciary duty of
care, provided that any such provision does not (in the words of the statute) do
any of the following:

         "eliminate or limit the liability of a director (i) for any breach of
         the director's duty of loyalty to the corporation or its stockholders,
         (ii) for acts or omissions not in good faith or which involve
         intentional misconduct or a knowing violation of law, (iii) under
         Section 174 of this Title [dealing with willful or negligent violation
         of the statutory provision concerning dividends and stock purchases and
         redemptions], or (iv) for any transaction from which the director
         derived an improper personal benefit. No such provision shall eliminate
         or limit the liability of a director for any act or omission occurring
         prior to the date when such provision becomes effective...."

         The DGCL further empowers the board of directors of the Registrant to
make other indemnification as authorized under the provisions of the restated
certificate of incorporation or bylaws, corporate resolution or agreement so
long as the indemnification is consistent with the DGCL.

         The Registrant's restated certificate of incorporation provides that,
to the fullest extent permitted by the DGCL, a director of the Registrant will
not be liable to the Registrant or its stockholders for monetary damages for
breach of fiduciary duty as a director. The Registrant's bylaws provide that to
the extent that a director, officer, employee or agent of the Registrant is
successful on the merits of defense of a suit or proceeding brought against him
by reason of his position within the Registrant, he shall be indemnified against
expenses (including attorneys'

                                      II-2
7

fees) actually and reasonably incurred in connection with such action. In other
circumstances, a director, officer employee or agent of the Registrant may be
indemnified against expenses (including attorneys' fees), judgments, fines and
amounts paid in settlement actually and reasonably incurred by him in connection
with such action, suit or proceeding if he acted in good faith and in a manner
he reasonably believed to be in and not opposed to the best interest of the
Registrant, and, with respect to a criminal action or proceeding, had no
reasonable cause to believe his conduct was unlawful; however, in an action or
suit by or in the right of the Registrant to procure a judgment in its favor,
such person will not be indemnified if he has been adjudged to be liable to the
Registrant unless and only to the extent that the Delaware Court of Chancery or
the court in which such action or suit was brought determines upon application
that, despite the adjudication of liability but in view of all the circumstances
of the case, such person is fairly and reasonably entitled to indemnity for such
expenses which the Court of Chancery or such other court deems proper. A
determination that indemnification is proper will be made by a majority of the
Registrant's disinterested directors, by independent legal counsel or by the
stockholders of the Registrant. The Registrant's bylaws also provide that the
Registrant may advance the payment of expenses and that the indemnification and
advancement of expense provisions of the bylaws are nonexclusive. The Registrant
maintains director and officer liability insurance covering director and officer
indemnification.

         In addition, the Merger Agreement provides that the Registrant will
indemnify the former officers and directors of UTI from liabilities arising out
of actions or omissions in their capacity as such prior to the effective time of
the Merger, and advance reasonable litigation expenses incurred in connection
with such actions or omissions, to the full extent permitted under UTI's
certificate of incorporation and bylaws. In addition, for a period of six years
after the effective time of the Merger, the Registrant will provide UTI's
officers and directors with an insurance and indemnification policy that
provides coverage through the effective time of the Merger; provided that the
maximum aggregate amount of premiums that the Registrant will be required to pay
to provide and maintain this coverage does not exceed $300,000 per year.

ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.

         Not Applicable.

ITEM 8.  EXHIBITS.

         The Exhibits listed in the accompanying Exhibit Index are filed or
incorporated by reference as part of this Registration Statement.

ITEM 9.  UNDERTAKINGS.

A.       The undersigned Registrant hereby undertakes:

         (1) To file, during any period in which offers or sales are being made,
a post-effective amendment to this registration statement: (i) to include any
prospectus required by Section 10(a)(3) of the Securities Act; (ii) to reflect
in the prospectus any facts or events arising after the effective date of the
registration statement (or the most recent post-effective amendment thereof)
which, individually or in the aggregate, represent a fundamental change in the
information set

                                      II-3
8

forth in the registration statement. Notwithstanding the foregoing, any decrease
or increase in volume of securities offered (if the total dollar value of the
securities offered would not exceed that which was registered) and any deviation
from the low or the high end of the estimated maximum offering range may be
reflected in the form of a prospectus filed with the Commission pursuant to Rule
424(b) if, in the aggregate, the changes in volume and price represent no more
than a 20% change in the maximum aggregate offering price set forth in the
"Calculation of Registration Fee" table in this Registration Statement; and
(iii) to include any material information with respect to the plan of
distribution not previously disclosed in the registration statement or any
material change to such information in the registration statement; provided,
however, that clauses (i) and (ii) do not apply if the information required to
be included in a post-effective amendment by those clauses is contained in
periodic reports filed with or furnished to the Commission by the Registrant
pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934,
as amended ("Exchange Act") that are incorporated by reference in this
Registration Statement;

         (2) That, for the purpose of determining any liability under the
Securities Act, each such post-effective amendment shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof; and

         (3) To remove from registration by means of a post-effective amendment
any of the securities being registered that remain unsold at the termination of
the offering.

B.       The undersigned Registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act, each filing of the
Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
Exchange Act (and, where applicable, each filing of an employee benefit plan's
annual report pursuant to Section 15(d) of the Exchange Act) that is
incorporated by reference in the registration statement shall be deemed to be a
new registration statement relating to the securities offered therein, and the
offering of such securities at that time shall be deemed to be the initial bona
fide offering thereof.

C.       Insofar as indemnification for liabilities arising under the Securities
Act may be permitted to directors, officers and controlling persons of the
Registrant pursuant to the provisions described under Item 6 above or otherwise,
the Registrant has been advised that in the opinion of the Commission such
indemnification is against public policy as expressed in the Securities Act and
is, therefore, unenforceable. In the event that a claim for indemnification
against such liabilities (other than the payment by the Registrant of expenses
incurred or paid by a director, officer or controlling person of the Registrant
in the successful defense of any action, suit or proceeding) is asserted by such
director, officer or controlling person in connection with the securities being
registered, the Registrant will, unless in the opinion of its counsel the matter
has been settled by controlling precedent, submit to a court of appropriate
jurisdiction the question whether such indemnification by it is against public
policy as expressed in the Securities Act and will be governed by the final
adjudication of such issue.

                                      II-4
9

                                   SIGNATURES

         Pursuant to the requirements of the Securities Act, the Registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-8 and has duly caused this Registration
Statement to be signed on its behalf by the undersigned, thereunto duly
authorized, in the City of Houston, State of Texas, on the 8th day of May, 2001.

                                                PATTERSON-UTI ENERGY, INC.

                                                By:  /s/ CLOYCE A. TALBOTT
                                                    -----------------------
                                                    Cloyce A. Talbott
                                                    Chief Executive Officer

         KNOW ALL MEN BY THESE PRESENTS, that each person whose signature
appears below constitutes and appoints Cloyce A. Talbott and A. Glenn Patterson,
or either of them, severally, as his/her attorney-in-fact and agent, with full
power of substitution and resubstitution, for him/her and in his/her name,
place, and stead, in any and all capacities, to sign any and all post-effective
amendments to this Registration Statement, and to file the same with all
exhibits hereto, and all other documents in connection herewith, with the
Commission, granting unto said attorney-in-fact and agent, and either of them,
full power and authority to do and perform each and every act and thing
requisite or necessary to be done in and about the premises, as fully to all
intents and purposes as he/she might or could do in person, hereby ratifying and
confirming all that said attorneys-in-fact and agents, or either of them, or
their or his substitutes, may lawfully do or cause to be done by virtue hereof.

         Pursuant to the requirements of the Securities Act, this Registration
Statement has been signed by the following persons in the capacities indicated
on the 8th day of May, 2001.
SIGNATURE                                TITLE
            ---------                                -----
/s/ CLOYCE A. TALBOTT          Chief Executive Officer, Director (principal
--------------------------         executive officer)
    Cloyce A. Talbott

    /s/ JONATHAN D. NELSON         Vice President-Finance, Chief Financial Officer,
--------------------------         Secretary, Treasurer (principal financial
   Jonathan D. Nelson              officer and principal accounting officer)

    /s/ MARK S. SIEGEL             Chairman of the Board, Director
--------------------------
     Mark S. Siegel

    /s/ A. GLENN PATTERSON
--------------------------
    A. Glenn Patterson             President, Chief Operating Officer, Director
II-5
10
/s/ SPENCER D. ARMOUR, III
------------------------------
   Spencer D. Armour, III          Director

    /s/ KENNETH N. BERNS
------------------------------
     Kenneth N. Berns              Director

    /s/ STEPHEN J. DeGROAT
------------------------------
    Stephen J. DeGroat             Director

    /s/ VAUGHN E. DRUM
------------------------------
     Vaughn E. Drum                Director

    /s/ ROBERT C. GIST
------------------------------
     Robert C. Gist                Director

    /s/ CURTIS W. HUFF
------------------------------
      Curtis W. Huff               Director

    /s/ KENNETH R. PEAK
------------------------------
     Kenneth R. Peak               Director

    /s/ NADINE C. SMITH
------------------------------
     Nadine C. Smith               Director
II-6
11

                                  EXHIBIT INDEX
EXHIBIT
        NUMBER                  EXHIBIT DESCRIPTION
        -------                 -------------------
4.1      Restated Certificate of Incorporation(1)

         4.2      Bylaws(2)

         4.3      Stockholder Rights Plan dated January 2, 1997 between
                  Patterson Energy, Inc. and Continental Stock Transfer & Trust
                  Company, as rights agent(3)

         4.4      Amended and Restated UTI Energy Corp. 1996 Employee Stock
                  Option Plan

         4.5      Amended and Restated Non-Employee Director Stock Option Plan
                  of UTI Energy Corp.

         5.1      Opinion of Baker & Hostetler LLP

        15.1      Awareness Letter of PricewaterhouseCoopers LLP

        23.1      Consent of Independent Accountants, PricewaterhouseCoopers LLP

        23.2      Consent of M. Brian Wallace, Independent Petroleum Engineer

        23.3      Consent of Baker & Hostetler LLP(4)

        24.1      Power of Attorney(5)
(1)      Incorporated herein by reference to Item 7, "Financial Statements and
         Exhibits" to Current Report on Form 8-K; filed with the Commission on
         May 8, 2001.

(2)      Incorporated herein by reference to Item 27, "Exhibits" to Amendment
         No. 2 to Registration Statement on Form SB-2 (File No. 33-68058-FW);
         filed October 28, 1993.

(3)      Incorporated herein by reference to Item 2, "Exhibits" to Registration
         Statement on Form 8-A; filed January 14, 1997.

(4)      Included in Opinion of Baker & Hostetler, LLP; filed as Exhibit 5.1.

(5)      Included in the signature page to this Registration Statement.