PTEN Patterson UTI Energy Inc

SUMMARY

This summary highlights information contained elsewhere in this joint proxy statement/prospectus and may not contain all the information that is important to you with respect to the merger and the other matters being considered at the Patterson-UTI and SSE special meetings. Patterson-UTI and SSE urge you to read the remainder of this joint proxy statement/prospectus carefully, including the attached Annexes, and the other documents to which we have referred you. See also the section titled “Where You Can Find More Information” beginning on page 233. We have included page references in this summary to direct you to a more complete description of the topics presented below.

The Companies

Patterson-UTI Energy, Inc.

Patterson-UTI Energy, Inc., a Delaware corporation, is a Houston, Texas-based oilfield services company that primarily owns and operates in the United States one of the largest fleets of land-based drilling rigs and a large fleet of pressure pumping equipment. Patterson-UTI’s contract drilling business operates in the continental United States and western Canada, and its pressure pumping business operates primarily in Texas and the Appalachian region. Patterson-UTI also manufactures and sells pipe handling components and related technology to drilling contractors in North America and other select markets. In addition, Patterson-UTI owns and invests as a non-operating working interest owner in oil and natural gas assets that are primarily located in Texas and New Mexico. As of December 31, 2016, Patterson-UTI had a drilling fleet that included 161 APEX ^® rigs. As of December 31, 2016, Patterson-UTI had approximately 1.1 million hydraulic horsepower to provide pressure pumping services.

Patterson-UTI’s common stock is traded on the Nasdaq Global Select Market under the symbol “PTEN.”

The principal executive offices of Patterson-UTI are located at 10713 West Sam Houston Parkway North, Suite 800, Houston, Texas 77064, and Patterson-UTI’s telephone number is (281) 765-7100. Additional information about Patterson-UTI and its subsidiaries is included in documents incorporated by reference into this joint proxy statement/prospectus. See “Where You Can Find More Information” on page 233.

Seventy Seven Energy Inc.

Seventy Seven Energy Inc., a Delaware corporation, is an Oklahoma City, Oklahoma-based independent oilfield services company that provides a wide range of wellsite services and equipment to U.S. land-based exploration and production customers operating in unconventional resource plays. SSE offers services and equipment that are strategic to its customers’ oil and natural gas operations. SSE’s services include drilling, hydraulic fracturing and oilfield rentals. SSE’s operations are geographically diversified across many of the most active oil and natural gas plays in the onshore United States, including the Anadarko and Permian Basins and the Eagle Ford, Haynesville, Marcellus, Niobrara and Utica Shales. On June 30, 2014, SSE separated from Chesapeake Energy Corporation (“CHK”) in a series of transactions, which is referred to in this joint proxy statement/prospectus as the “spin-off.” Prior to the spin-off, SSE was an Oklahoma limited liability company operating under the name “Chesapeake Oilfield Operating, L.L.C.” and an indirect, wholly-owned subsidiary of CHK.

SSE’s common stock is traded on the OTC Market Group Inc.’s OTC Grey market (the “OTC Grey”) under the symbol “SVNT.”

The principal executive offices of SSE are located at 777 NW 63rd St., Oklahoma City, Oklahoma 73116, and SSE’s telephone number is (405) 608-7777.

Pyramid Merger Sub, Inc.

Pyramid Merger Sub, Inc., a wholly owned subsidiary of Patterson-UTI, is a Delaware corporation that was formed on December 7, 2016 for the sole purpose of effecting the merger. In the merger, Merger Sub will be merged with and into SSE, with SSE surviving the merger as a wholly owned subsidiary of Patterson-UTI.

The Meetings

The Patterson-UTI Special Meeting (see page 63)

The special meeting of Patterson-UTI stockholders will be held at Patterson-UTI’s executive offices at 10713 West Sam Houston Parkway North, Suite 800, Houston, Texas 77064 on                 , at                 , local time. The special meeting of Patterson-UTI stockholders is being held to consider and vote on:

Completion of the merger is conditioned on approval by Patterson-UTI stockholders of the issuance of Patterson-UTI common stock pursuant to the merger agreement.

Only record holders of shares of Patterson-UTI common stock at the close of business on February 22, 2017, the record date for the Patterson-UTI special meeting, are entitled to notice of, and to vote at, the Patterson-UTI special meeting. At the close of business on the record date, the only outstanding voting securities of Patterson-UTI were common stock, and 166,327,753 shares of Patterson-UTI common stock were issued and outstanding, approximately          of which were owned and entitled to be voted by Patterson-UTI directors and executive officers. The Patterson-UTI directors and executive officers are currently expected to vote their shares in favor of each Patterson-UTI proposal listed above.

With respect to each Patterson-UTI proposal listed above, Patterson-UTI stockholders may cast one vote for each share of Patterson-UTI common stock that they own as of the Patterson-UTI record date. The proposal to approve the issuance of Patterson-UTI common stock requires the affirmative vote of a majority of the shares of Patterson-UTI common stock, present in person or represented by proxy at the Patterson-UTI special meeting and entitled to vote thereon. The proposal to approve the adjournment of the Patterson-UTI special meeting, if necessary or appropriate, to solicit additional proxies requires the affirmative vote of a majority of the shares of Patterson-UTI common stock, present in person or represented by proxy at the Patterson-UTI special meeting and entitled to vote on the proposal, regardless of whether there is a quorum.

No business may be transacted at the Patterson-UTI special meeting unless a quorum is present. If a quorum is not present at the special meeting, or if a quorum is present at the special meeting but there are not sufficient votes at the time of the special meeting to approve the proposal to issue shares of Patterson-UTI common stock in connection with the merger, then the chairman of the meeting has the power to adjourn the meeting, or, alternatively, Patterson-UTI stockholders may be asked to vote on a proposal to adjourn the Patterson-UTI special meeting in order to permit the further solicitation of proxies. No notice of an adjourned meeting need be given unless the date, time and place of the resumption of the meeting are not announced at the adjourned meeting, the adjournment is for more than 30 days or, if after the adjournment, a new record date is fixed for the adjourned meeting, in which case a notice of the adjourned meeting shall be given to each stockholder of record entitled to vote at the meeting.

Reasons for the Merger; Recommendation of the Patterson-UTI Board of Directors (see page 83)

The Patterson-UTI board of directors unanimously approved the merger agreement, the merger and the other transactions contemplated by the merger agreement, and declared the merger agreement, the merger and the other transactions contemplated by the merger agreement (including the issuance of shares of Patterson-UTI common stock to SSE stockholders in connection with the merger) to be advisable and fair to and in the best interests of Patterson-UTI stockholders. The Patterson-UTI board of directors unanimously recommends that Patterson-UTI stockholders vote “FOR” the proposal to approve the issuance of Patterson-UTI common stock pursuant to the merger agreement and “FOR” the proposal to approve the adjournment of the Patterson-UTI special meeting to a later date or dates, if necessary or appropriate to solicit additional proxies in the event there are not sufficient votes at the time of the special meeting to approve the issuance of shares of Patterson-UTI common stock. For more information regarding the factors considered by the Patterson-UTI board of directors in reaching its decisions relating to its recommendation, see the section titled “The Merger—Patterson-UTI’s Reasons for the Merger; Recommendation of the Patterson-UTI Board of Directors.”

Opinion of Patterson-UTI’s Financial Advisor (see page 86)

Patterson-UTI engaged Piper Jaffray & Co., through its Simmons & Company International division (referred to as “Piper Jaffray”), to act as financial advisor in connection with the transactions contemplated by the merger agreement. On December 12, 2016, Piper Jaffray delivered to the Patterson-UTI board of directors its oral opinion, confirmed by its delivery of a written opinion dated December 12, 2016, that, as of the date thereof, and based upon and subject to the assumptions, procedures, factors, qualifications, limitations and other matters set forth in Piper Jaffray’s written opinion, the up to 49,559,000 shares of Patterson-UTI common stock to be issued for all outstanding shares of SSE pursuant to the merger agreement was fair, from a financial point of view, to Patterson-UTI.

The full text of Piper Jaffray’s written opinion dated December 12, 2016, which sets forth, among other things, the assumptions made, procedures followed, matters considered and qualifications and limitations on the scope of review undertaken by Piper Jaffray in delivering its opinion, is attached as Annex C to this proxy statement/prospectus and is incorporated herein by reference in its entirety.

Piper Jaffray’s opinion was addressed to, and provided for the information and benefit of, the Patterson-UTI board of directors and was delivered to the Patterson-UTI board of directors in connection with its evaluation of the fairness of the merger consideration from a financial point of view, to Patterson-UTI, and did not address any other aspects or implications of the transactions contemplated by the merger agreement. Piper Jaffray’s opinion does not constitute a recommendation to the Patterson-UTI board of directors or to any other persons in respect of the transactions contemplated by the merger agreement, including as to how any holder of Patterson-UTI common stock should vote or act with respect to the proposal to adopt any other matter. Piper Jaffray’s opinion did not address the relative merits of the transactions contemplated by the merger agreement compared to other business or financial strategies that might be available to Patterson-UTI, nor did it address the underlying business decision of Patterson-UTI to enter into the merger agreement or to consummate the transactions contemplated by the merger agreement.

For a more complete discussion of Piper Jaffray’s opinion, see “The Merger—Opinion of Patterson-UTI’s Financial Advisor” beginning on page 86 .

The SSE Special Meeting (see page 68)

The special meeting of SSE stockholders will be held at SSE’s executive offices at 777 N.W. 63rd Street, Oklahoma City, Oklahoma 73116, on                 , 2017, at                 , local time. The special meeting of SSE stockholders is being held in order to consider and vote on:

Completion of the merger is conditioned on approval and adoption of the merger agreement and the transactions contemplated by the merger agreement, including the merger, by the SSE stockholders. The proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to SSE’s named executive officers in connection with the merger is a vote separate and apart from the vote on the proposal to adopt the merger agreement. Accordingly, a SSE stockholder may vote to approve one proposal and not the other. Because the vote on the proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to SSE’s named executive officers in connection with the merger is advisory in nature only, it will not be binding on SSE or Patterson-UTI, and the approval of that proposal is not a condition to the completion of the merger.

Only record holders of shares of SSE common stock at the close of business on February 22, 2017, the record date for the SSE special meeting, are entitled to notice of, and to vote at, the SSE special meeting. At the close of business on the record date, the only outstanding voting securities of SSE were common stock, and 22,949,374 shares of SSE common stock were issued and outstanding and entitled to vote at the SSE special meeting, approximately              of which were owned and entitled to be voted by SSE directors and executive officers. The SSE directors and executive officers are currently expected to vote their shares in favor of each of the SSE proposals listed above.

In connection with the execution of the merger agreement, certain affiliates of Axar Capital Management, LLC, BlueMountain Capital Management, LLC and Mudrick Capital Management, L.P. have entered into voting and support agreements with Patterson-UTI, pursuant to which each such stockholder agreed to vote all of its shares of SSE common stock in favor of the adoption of the merger agreement and against, among other things, alternative transactions. As of the date of this joint proxy statement/prospectus, those stockholders hold and are entitled to vote in the aggregate approximately 59% of the issued and outstanding shares of SSE common stock entitled to vote at the SSE special meeting. In the event that SSE’s board of directors changes its recommendation that SSE stockholders adopt the merger agreement, such stockholders, taken together, will be required to vote shares that, in the aggregate, represent 39.99% of the issued and outstanding shares of SSE common stock on such proposal, with each such stockholder being able to vote the balance of its shares of SSE common stock on such proposal in such stockholder’s sole discretion. See “The Merger Agreement—Voting and Support Agreements” beginning on page 148 for more information.

With respect to each SSE proposal listed above, SSE stockholders may cast one vote for each share of SSE common stock that they own as of the SSE record date. The proposal to adopt the merger agreement requires the affirmative vote of a majority of the outstanding shares of SSE common stock entitled to vote thereon. The proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to SSE’s named executive officers in connection with the merger requires the affirmative vote of a majority of

the voting power of the outstanding shares present in person or represented by proxy at the special meeting and entitled to vote thereon, assuming a quorum is present. The proposal to approve adjournment of the SSE special meeting, if necessary or appropriate, to solicit additional proxies requires the affirmative vote of a majority of the voting power of the outstanding shares present in person or represented by proxy at the special meeting and entitled to vote thereon, regardless of whether there is a quorum.

No business may be transacted at the SSE special meeting unless a quorum is present. If a quorum is not present, or if fewer shares are voted in favor of the proposal to adopt the merger agreement, than is required, then the chairman of the meeting has the power to adjourn the meeting, or, alternatively, SSE stockholders may be asked to vote on a proposal to adjourn the SSE special meeting in order to permit the further solicitation of proxies. No notice of an adjourned meeting need be given unless the date, time and place of the resumption of the meeting are not announced at the adjourned meeting, the adjournment is for more than 30 days, or, if after the adjournment, a new record date is fixed for the adjourned meeting, in which cases a notice of the adjourned meeting shall be given to each stockholder of record entitled to vote at the meeting.

Reasons for the Merger; Recommendation of the SSE Board of Directors (see page 95)

The SSE board of directors unanimously approved the merger agreement, the merger and the other transactions contemplated by the merger agreement, and declared the merger agreement, the merger and the other transactions contemplated by the merger agreement to be advisable and fair to and in the best interests of SSE stockholders. The SSE board of directors unanimously recommends that SSE stockholders vote “FOR” the proposal to adopt the merger agreement, “FOR” the proposal to approve, on an advisory (non-binding) basis, the compensation that may be paid or become payable to SSE’s named executive officers in connection with the merger and “FOR” the proposal to approve the adjournment of the SSE special meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the special meeting to adopt the merger agreement. For more information regarding the factors considered by the SSE board of directors in reaching its decision to recommend the approval of the merger agreement, see the section titled “The Merger—SSE’s Reasons for the Merger; Recommendation of the SSE Board of Directors.”

Opinion of SSE’s Financial Advisor (see page 98)

SSE retained Morgan Stanley & Co. LLC, which we refer to in this joint proxy statement/prospectus as “Morgan Stanley,” in connection with the merger. On December 12, 2016, Morgan Stanley rendered to the SSE board of directors its oral opinion, subsequently confirmed in writing on December 12, 2016, that, as of such date and based upon and subject to the various assumptions made, procedures followed, matters considered and qualifications and limitations on the scope of the review undertaken by Morgan Stanley as set forth in its written opinion, the consideration to be received by SSE stockholders pursuant to the merger agreement was fair, from a financial point of view, to the holders of SSE common stock. The full text of Morgan Stanley’s written opinion dated as of December 12, 2016, to the SSE board of directors, which sets forth, among other things, the assumptions made, procedures followed, matters considered and qualifications and limitations on the scope of review undertaken by Morgan Stanley in rendering its opinion, is attached as Annex D to, and is incorporated by reference into, this joint proxy statement/prospectus. The summary of the opinion of Morgan Stanley in this joint proxy statement/prospectus is qualified in its entirety by reference to the full text of the opinion. We encourage you to read Morgan Stanley’s opinion and the summary of Morgan Stanley’s opinion below carefully and in their entirety.

Morgan Stanley’s opinion was rendered for the benefit of the SSE board of directors, in its capacity as such, and addressed only the fairness, from a financial point of view, of the consideration to be received by SSE stockholders pursuant to the merger agreement to the holders of SSE common stock as of the date of

the opinion. Morgan Stanley’s opinion does not address any of the relative merits of the transactions contemplated by the merger agreement as compared to other business or financial strategies that might be available to SSE, nor does it address the underlying business decision of SSE to enter into the merger agreement or proceed with any other transaction contemplated by the merger agreement. In addition, Morgan Stanley’s opinion does not in any manner address the prices at which Patterson-UTI common stock will trade following the consummation of the merger or at any time. The opinion was addressed to, and rendered for the benefit of, the SSE board of directors and was not intended to, and does not, constitute advice or a recommendation to any holder of SSE common stock as to how to vote or act on any matter with respect to the merger.

For a more complete discussion of Morgan Stanley’s opinion, see “The Merger—Opinion of SSE’s Financial Advisor” beginning on page 98.

The Merger

A copy of the merger agreement is attached as Annex A to this joint proxy statement/prospectus. Patterson-UTI and SSE encourage you to read the entire merger agreement carefully because it is the principal document governing the merger. For more information on the merger agreement, see the section titled “The Merger Agreement” beginning on page 125.

Form of the Merger (see page 125)

Subject to the terms and conditions of the merger agreement, at the effective time, Merger Sub, a wholly owned subsidiary of Patterson-UTI that was formed for the sole purpose of effecting the merger, will merge with and into SSE. SSE will survive the merger and become a wholly owned subsidiary of Patterson-UTI.

Merger Consideration (see page 125)

Each issued and outstanding share of SSE common stock, other than shares owned by SSE and its wholly owned subsidiaries, shares owned by Patterson-UTI or Merger Sub and shares for which appraisal rights held by SSE stockholders have been perfected in compliance with Section 262 of the DGCL, will be converted into the right to receive a number of shares of Patterson-UTI common stock equal to the exchange ratio. The exchange ratio will be equal to 49,559,000 shares of Patterson-UTI common stock, divided by the total number of shares of SSE common stock outstanding or deemed outstanding immediately prior to the effective time (which includes (i) shares of SSE common stock outstanding as a result of the exercise of warrants to acquire SSE common stock, (ii) shares of SSE common stock deemed outstanding as a result of the vesting of SSE restricted stock unit awards that existed prior to the execution of the merger agreement, (iii) any shares of SSE common stock subject to perfected appraisal rights, (iv) shares of SSE common stock that underlie restricted stock unit awards that SSE issues on or after the execution of the merger agreement and (v) 50% of any shares of SSE common stock that have been tendered to SSE on or after August 1, 2016 for the purposes of satisfying tax withholding obligations upon the vesting of SSE restricted stock unit awards); provided that, in the event that any Series A warrants to acquire shares of SSE common stock are forfeited or net settled, such 49,559,000 shares of Patterson-UTI common stock will be reduced by a number equal to (i) the aggregate exercise price for the warrants that are forfeited or net settled, divided by (ii) the volume weighted average price of a share of Patterson-UTI common stock for the ten consecutive trading days immediately preceding the third business day prior to the closing. In no event will Patterson-UTI issue more than 49,559,000 shares of its common stock as merger consideration. Annex B of this joint proxy statement/prospectus sets forth illustrative calculations of the exchange ratio.

In addition, Patterson-UTI will not issue fractional shares of SSE common stock pursuant to the merger agreement. Instead, each SSE stockholder who otherwise would have been entitled to receive a fraction of a share

of Patterson-UTI common stock will receive cash (without interest) in lieu thereof, upon surrender of his or her shares of SSE common stock. The exchange agent will aggregate and sell all fractional shares issuable as part of the merger consideration at the prevailing price on the NASDAQ. An SSE stockholder who would otherwise have received a fraction of a share of Patterson-UTI common stock will receive an amount of cash generated from such sales attributable to the stockholder’s proportionate interest in the net proceeds of such sales, less expenses and without interest.

The exchange ratio will not be adjusted for changes in the market value of the common stock of SSE or Patterson-UTI. As a result, the implied value of the consideration to SSE stockholders will fluctuate between the date of this joint proxy statement/prospectus and the effective time. Based on the closing price of Patterson-UTI common stock on the NASDAQ on December 12, 2016, the last trading day before public announcement of the merger, the aggregate transaction value of the merger consideration payable to SSE stockholders was approximately $1.42 billion, assuming the issuance of 49,559,000 shares of Patterson-UTI common stock.

Treatment of SSE Incentive Plan Restricted Stock Unit Awards (see page 114)

Each SSE restricted stock unit award granted prior to December 12, 2016 that is outstanding as of immediately prior to the effective time will immediately vest, and any forfeiture restrictions applicable to all such awards will immediately lapse. Such restricted stock unit awards will be deemed settled, and shares of SSE common stock subject to such awards will be treated as shares of SSE common stock and receive the merger consideration. In addition, at the effective time, each SSE restricted stock unit award granted on or following December 12, 2016 will be assumed by Patterson-UTI and converted into a restricted stock unit award, with the same terms and conditions as in effect immediately prior to the effective time, covering a number of shares of Patterson-UTI common stock equal to (i) the number of shares of SSE common stock subject to the award immediately prior to the effective time, multiplied by (ii) the exchange ratio (discussed above), rounded to the nearest whole share.

Expected Timing of the Merger

Patterson-UTI and SSE currently expect the closing of the merger to occur late in the first quarter or early in the second quarter of 2017. However, the merger is subject to the satisfaction or waiver of conditions as described in the merger agreement, and it is possible that factors outside the control of Patterson-UTI and SSE could result in the merger being completed at an earlier time, a later time or not at all.

Conditions to Completion of the Merger (see page 142)

The respective obligations of Patterson-UTI, SSE and Merger Sub to effect the merger and otherwise consummate the transactions contemplated by the merger agreement are subject to the satisfaction or waiver of the following conditions at or before the closing date:

In addition, Patterson-UTI’s and Merger Sub’s obligations to effect the merger are subject to the satisfaction or waiver of the following additional conditions:

In addition, SSE’s obligations to effect the merger is subject to the satisfaction or waiver of the following additional conditions:

Debt Financing (see page 134)

In connection with the merger, Patterson-UTI entered into a financing commitment letter with Canyon Capital Advisors LLC for a senior unsecured bridge facility in an aggregate principal amount not to exceed $150 million for the purposes of repaying or redeeming certain of SSE and its subsidiaries’ indebtedness and to pay related fees and expenses. Any undrawn commitments under the bridge facility will automatically terminate on the closing date. Patterson-UTI may issue debt securities or equity, incur bank loans or consummate other financings or use cash on hand in lieu of drawing all or a portion of the bridge loan committed to be funded under the bridge facility.

No Solicitation of Competing Proposals (see page 135)

The merger agreement generally precludes SSE from, directly or indirectly, (i) soliciting, initiating, facilitating, knowingly encouraging or inducing or taking any action that could be reasonably expected to lead to the making, submission or announcement of a proposal competing with the transactions contemplated by the merger agreement, (ii) furnishing any nonpublic information regarding SSE or its subsidiaries to any third party in connection with or in response to a proposal competing with the transactions contemplated by the merger agreement, (iii) engaging in discussions or negotiations with any third party with respect to a proposal competing with the transactions contemplated by the merger agreement, (iv) approving, endorsing, or recommending a proposal competing with the transactions contemplated by the merger agreement or (v) entering into any agreement contemplating or otherwise relating to a proposal competing with the transactions contemplated by the merger agreement. However, if SSE receives a proposal meeting certain requirements from a third party, and the SSE board of directors determines in good faith, after consultation with its outside legal counsel and its outside financial advisor, that such competing proposal is or is reasonably likely to result in a superior proposal, and that the failure to take such action would be inconsistent with its fiduciary duties under applicable legal requirements, SSE may furnish non-public information to, and engage in discussions or negotiations with, that third party regarding such competing proposal. See the section titled “The Merger Agreement—No Solicitation of Competing Proposals.”

In addition, the merger agreement generally precludes Patterson-UTI from, directly or indirectly, (i) soliciting, initiating, facilitating, knowingly encouraging or inducing or taking any action that could be reasonably expected to lead to the making, submission or announcement of a proposal competing with the transactions contemplated by the merger agreement, (ii) furnishing any nonpublic information regarding Patterson-UTI or its subsidiaries to any third party in connection with or in response to a proposal competing with the transactions contemplated by the merger agreement, (iii) engaging in discussions or negotiations with any third party with respect to a proposal competing with the transactions contemplated by the merger agreement, (iv) approving, endorsing, or recommending a proposal competing with the transactions contemplated by the merger agreement or (v) entering into any agreement contemplating or otherwise relating to a proposal competing with the transactions contemplated by the merger agreement. However, if Patterson-UTI receives a proposal meeting certain requirements from a third party, and the Patterson-UTI board of directors determines in good faith, after consultation with its outside legal counsel and its outside financial advisor, that such competing proposal is or is reasonably likely to result in a superior proposal, and that the failure to take such action would be inconsistent with its fiduciary duties under applicable legal requirements, Patterson-UTI may furnish

non-public information to, and engage in discussions or negotiations with, that third party regarding such competing proposal. See the section titled “The Merger Agreement—No Solicitation of Competing Proposals.”

Changes in Board Recommendations (see page 138)

The merger agreement generally provides that, subject to the exceptions described below, SSE may not change its recommendation that SSE stockholders adopt the merger agreement, and Patterson-UTI may not change its recommendation that Patterson-UTI stockholders approve the issuance of Patterson-UTI common stock in the merger.

However, notwithstanding the foregoing, the merger agreement provides that, prior to obtaining SSE stockholder approval of the merger and in response to a bona fide competing proposal that did not result from a material breach of the non-solicitation covenants and certain related covenants, SSE may effect a change of recommendation after satisfaction of certain conditions set forth under “The Merger Agreement—Changes in Board Recommendations.” In addition, the merger agreement provides that, prior to obtaining SSE stockholder approval of the merger and in response to an intervening event with respect to SSE, SSE may effect a change of recommendation after satisfaction of certain conditions set forth under “The Merger Agreement—Changes in Board Recommendations.”

The merger agreement also provides that, prior to obtaining Patterson-UTI stockholder approval of the proposed issuance of Patterson-UTI common stock in the merger and in response to a bona fide competing proposal that did not result from a material breach of the non-solicitation covenants and certain related covenants or an intervening event with respect to Patterson-UTI, the Patterson-UTI board of directors or any committee thereof may effect a change of recommendation after satisfaction of certain conditions set forth under “The Merger Agreement—Changes in Board Recommendations.”

Termination of the Merger Agreement (see page 144)

The merger agreement may be terminated prior to the effective time under the following circumstances:

Termination Fees and Expenses (see page 146)

Generally, all fees and expenses incurred in connection with the merger agreement and the transactions contemplated by the merger agreement will be paid by the party incurring those expenses, subject to the specific exceptions discussed in this joint proxy statement/prospectus. In certain circumstances, SSE or Patterson-UTI may be required to pay up to $7,500,000 of the other party’s expenses, SSE may be required to pay Patterson-UTI a termination fee of $40,000,000, or Patterson-UTI may be required to pay SSE a termination fee of either $40,000,000 or $100,000,000. See the section titled “The Merger Agreement—Termination Fees and Expenses” beginning on page 146 for a discussion of the circumstances under which such termination fee will be required to be paid.

Comparison of Stockholder Rights and Corporate Governance Matters (see page 168)

The governing corporate documents of SSE differ from the governing corporate documents of Patterson-UTI. As a result, SSE stockholders that receive Patterson-UTI common stock as merger consideration will have different rights once they become stockholders of Patterson-UTI. These differences are described in detail under the section titled “Comparison of Rights of Patterson-UTI Stockholders and SSE Stockholders.”

Listing of Patterson-UTI Common Stock; Halting of Trading of SSE Common Stock (see page 121)

It is a condition to the completion of the merger that the shares of Patterson-UTI common stock to be issued to SSE stockholders be authorized for listing on the NASDAQ at the effective time, subject to official notice of issuance. Upon completion of the merger, shares of SSE common stock will cease to be traded on the OTC Grey.

Interests of SSE Directors and Executive Officers in the Merger (see page 113)

SSE’s directors and executive officers have interests in the merger that may be different from, or in addition to, the interests of the SSE stockholders generally. The members of the SSE board of directors were aware of and

considered these interests, among other matters, in evaluating and negotiating the merger agreement and the merger, and in recommending that SSE stockholders adopt the merger agreement.

These interests include, among others:

In addition, the SSE board of directors has adopted a resolution providing that the disposition of SSE shares by SSE’s officers and directors in exchange for Patterson-UTI shares in the merger is intended to be exempt from liability pursuant to Section 16(b) of the Exchange Act.

Regulatory Clearances Required to Complete the Transactions (see page 118)

Consummation of the merger is subject to the expiration or termination of any applicable waiting period under the HSR Act. On January 3, 2017, Patterson-UTI and SSE filed Notification and Report Forms with the Antitrust Division of the Department of Justice and the Federal Trade Commission, which is referred to as the FTC. On January 13, 2017, Patterson-UTI and SSE were notified by the FTC that the early termination of the waiting period under the HSR Act had been granted. See “The Merger—Regulatory Clearances Required for the Merger.”

Board of Directors and Executive Management Following the Merger (see page 118)

Following the completion of the merger, it is anticipated that the Patterson-UTI board of directors will have seven members, consisting of the seven individuals currently serving on the Patterson-UTI board of directors as of the date of this joint proxy statement/prospectus.

Following the completion of the merger, it is anticipated that each of the Patterson-UTI executive officers will continue to serve in their current positions and under the same compensation plans and arrangements that were in place prior to the merger.

Appraisal Rights (see page 121)

The holders of Patterson-UTI common stock are not entitled to appraisal rights in connection with the merger under Delaware law.

The holders of SSE common stock are entitled to appraisal rights in connection with the merger under Delaware law. SSE common stock held by stockholders that do not vote for approval of the merger and make a demand for appraisal in accordance with Delaware law will not be converted into Patterson-UTI common stock, but will be converted into the right to receive from the combined company consideration determined in accordance with Delaware law.

Exchange of Shares in the Merger (see page 126)

On or prior to the effective time, Patterson-UTI will enter into an agreement with a bank or trust company reasonably acceptable to SSE to act as agent for the holders of SSE common stock in connection with the merger and to receive the merger consideration and cash sufficient to pay cash (without interest) in lieu of fractional shares to which holders of fractional shares may become entitled. At the effective time, each share of SSE common stock outstanding immediately prior to the effective time, other than shares owned by SSE and its wholly owned subsidiaries, shares owned by Patterson-UTI or Merger Sub and shares for which appraisal rights held by SSE stockholders have been perfected, will be converted into the right to receive a number of shares of Patterson-UTI common stock equal to the exchange ratio (as defined above).

Promptly after the effective time, but in no event later than three business days after the closing date, Patterson-UTI will cause the exchange agent to mail to each holder of SSE common stock a letter of transmittal specifying, among other things, that delivery will be effected, and risk of loss and title to any certificates shall pass, only upon proper delivery of such certificates to the exchange agent, or in the case of book entry shares, upon adherence to the procedures set forth in the letter of transmittal and instructions explaining the procedure for surrendering SSE stock certificates in exchange for shares of Patterson-UTI common stock or, in the case of book entry shares, the surrender of such shares for payment of the merger consideration.

After the effective time, shares of SSE common stock, including shares for which appraisal rights held by SSE stockholders have been perfected, will no longer be outstanding. At the effective time, all such shares will be automatically canceled and will cease to exist, and each certificate or book entry share, if any, that previously represented shares of SSE common stock (other than shares for which appraisal rights have been perfected) will represent only the right to receive the merger consideration as described above, any cash (without interest) in lieu of fractional shares of Patterson-UTI common stock and any dividends or other distributions to which the holders of the certificates become entitled upon surrender of such certificates or book entry shares. Any shares of SSE common stock for which appraisal rights have been perfected will represent the right to payment of the fair value of such shares in accordance with the provisions of Section 262 of the DGCL. With respect to those shares of Patterson-UTI common stock deliverable upon the surrender of SSE stock certificates or book entry shares, until holders of such SSE stock certificates or book entry shares have surrendered those stock certificates or book entry shares to the exchange agent, those holders will not receive dividends or distributions declared or made with respect to such shares of Patterson-UTI common stock with a record date after the effective time.

SSE stockholders will not receive any fractional shares of Patterson-UTI common stock pursuant to the merger. Instead of any fractional shares, SSE stockholders will be paid an amount in cash (without interest) for such fraction of a share. The exchange agent will aggregate and sell all fractional shares issuable as part of the merger consideration at the prevailing price on the NASDAQ. An SSE stockholder who would otherwise have received a fraction of a share of Patterson-UTI common stock will receive an amount of cash generated from such sales attributable to the stockholder’s proportionate interest in the net proceeds of such sales, less expenses and without interest.

Patterson-UTI stockholders need not take any action with respect to their stock certificates.

Anticipated Accounting Treatment (see page 156)

Patterson-UTI prepares its financial statements in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”). The merger will be accounted for using the acquisition method of accounting with Patterson-UTI being considered the acquirer of SSE for accounting purposes. This means that Patterson-UTI will allocate the purchase price to the fair value of SSE’s tangible and intangible assets and liabilities at the acquisition date, with the excess purchase price being recorded as goodwill. Under the acquisition method of accounting, goodwill is not amortized but is tested for impairment at least annually.

Material U.S. Federal Income Tax Consequences (see page 153)

The merger is intended to qualify as a “reorganization” within the meaning of Section 368(a) of the Code. It is a condition to Patterson-UTI’s obligation to complete the merger that Patterson-UTI receive an opinion of Vinson & Elkins LLP, counsel to Patterson-UTI, to the effect that the merger will qualify as a “reorganization” within the meaning of Section 368(a) of the Code, and it is a condition to SSE’s obligation to complete the merger that SSE receive an opinion of Wachtell, Lipton, Rosen & Katz, special counsel to SSE, to the effect that the merger will qualify as a “reorganization” within the meaning of Section 368(a) of the Code. If the merger so qualifies, a U.S. holder (as defined under “Material U.S. Federal Income Tax Consequences”) of SSE common stock generally will not recognize any gain or loss for U.S. federal income tax purposes upon the exchange of shares of SSE common stock for shares of Patterson-UTI common stock pursuant to the merger, except with respect to cash received in lieu of fractional shares of Patterson-UTI common stock. For further information, see “Material U.S. Federal Income Tax Consequences” beginning on page 153.

Your tax consequences will depend on your individual situation. Accordingly, please consult your own tax advisor for a full understanding of the particular tax consequences of the merger to you.

Risk Factors (see page 35)

In evaluating the merger, in addition to the other information contained in this joint proxy statement/prospectus, you should carefully consider the risk factors relating to the merger and each of Patterson-UTI and SSE beginning on page 35.