Pioneer Southwest Energy Partners L.P. Reports Third Quarter 2013 Financial and Operating Results

Pioneer Southwest Energy Partners L.P. (“Pioneer Southwest” or “the Partnership”) (NYSE: PSE) today announced financial and operating results for the quarter ended September 30, 2013.

Pioneer Southwest reported third quarter net income of $16 million, or $0.44 per common unit. Net income for the third quarter included unrealized mark-to-market derivative losses of $5 million, or $0.13 per common unit. Without the effect of this item, adjusted income for the third quarter was $21 million, or $0.57 per common unit. Cash flow from operations for the third quarter was $29 million.

The Partnership’s three-rig drilling program continued during the third quarter, with 14 new vertical wells being placed on production. Oil and gas sales for the third quarter averaged 8,872 barrels oil equivalent per day (BOEPD). At the end of the quarter, the Partnership had nine vertical wells awaiting completion. Production continues to benefit from deeper vertical drilling to the Wolfcamp, Strawn and Atoka intervals. The Partnership has a large inventory of remaining oil drilling locations in the Spraberry field, with approximately 120 40-acre vertical locations and 1,275 20-acre vertical locations.

Pioneer Southwest expects to drill approximately 55 vertical wells during 2013. Capital expenditures are forecasted to be $135 million, including facilities. The 2013 drilling program is expected to generate production growth of 13% compared to 2012. Essentially all of the wells are expected to be drilled to the deeper Atoka interval. In addition, successful horizontal Wolfcamp Shale drilling by industry participants in Midland County and Martin County is encouraging for future horizontal drilling potential on the Partnership’s acreage in the area.

Third quarter oil sales averaged 5,792 barrels per day (BPD), natural gas liquids (NGL) sales averaged 1,848 BPD and gas sales averaged 7 million cubic feet per day. The third quarter average realized price for oil was $103.77 per barrel. The average realized price for NGLs was $33.11 per barrel, and the average realized price for gas was $3.07 per thousand cubic feet.

Production costs (including production and ad valorem taxes) for the third quarter averaged $26.36 per barrel oil equivalent (BOE). Depreciation, depletion and amortization expense for the third quarter averaged $10.89 per BOE.

The Partnership has additional borrowing capacity under its credit facility of $69 million as of September 30, 2013, which is expected to be adequate to fund remaining 2013 vertical drilling activities. The Partnership has also entered into derivative contracts that cover approximately 70% of forecasted fourth quarter 2013 production, 70% of forecasted 2014 production and 10% of forecasted 2015 production.

Pioneer Southwest previously announced a cash distribution of $0.52 per outstanding common unit for the quarter ended September 30, 2013. The distribution will be paid on November 12, 2013, to unitholders of record at the close of business on November 4, 2013.

Fourth Quarter 2013 Financial Outlook

The following paragraphs provide the Partnership’s fourth quarter of 2013 outlook for certain operating and financial items.

Production is forecasted to average 8,700 BOEPD to 9,200 BOEPD. Production costs (including production and ad valorem taxes) are expected to average $24.00 per BOE to $27.00 per BOE based on current NYMEX strip prices for oil, NGLs and gas. Depreciation, depletion and amortization expense is expected to average $10.50 per BOE to $11.50 per BOE. General and administrative expense is expected to be $1.5 million to $2.5 million. Interest expense is expected to be $1.0 million to $1.2 million. Accretion of discount on asset retirement obligations is forecasted to be nominal.

Pioneer Southwest’s effective income tax rate is expected to be approximately 1% of earnings before income taxes as a result of Pioneer Southwest being subject to the Texas Margin tax.

Merger Agreement with Pioneer Natural Resources Company

On August 9, 2013, the Partnership entered into an Agreement and Plan of Merger with Pioneer Natural Resources Company (“Pioneer”), Pioneer Natural Resources USA, Inc., a wholly-owned subsidiary of Pioneer (“Pioneer USA”), PNR Acquisition Company, LLC, a wholly-owned subsidiary of Pioneer (“MergerCo”), and Pioneer Natural Resources GP LLC, a wholly-owned subsidiary of Pioneer and the general partner of the Partnership (the “General Partner”), which was amended on October 25, 2013 (as amended, the “Merger Agreement”). Pursuant to the Merger Agreement, MergerCo will merge with and into the Partnership, with the Partnership surviving the merger (the “Merger”), such that following the Merger, the General Partner will remain a wholly-owned subsidiary of Pioneer and the sole general partner of the Partnership, and Pioneer USA will be the sole limited partner of the Partnership. Except for the common units owned by Pioneer, all of the common units outstanding as of the closing of the Merger will be cancelled and, except for dissenting common units, converted into the right to receive 0.2325 of a share of common stock of Pioneer per common unit. The parties anticipate that the Merger will close in the fourth quarter of 2013, pending the satisfaction of certain conditions; however, the Merger Agreement contains customary representations, warranties, covenants and conditions, some of which are beyond the parties’ control, which could delay or prevent the consummation of the Merger.

The Partnership will post a presentation related to its financial and operating results for the quarter ended September 30, 2013, on the Partnership’s website, www.pioneersouthwest.com. A copy of the presentation can be reviewed at the website by selecting “Investors,” then “Investor Presentations.”

Pioneer Southwest is a Delaware limited partnership, headquartered in Dallas, Texas, with current production and drilling operations in the Spraberry field in West Texas. For more information, visit www.pioneersouthwest.com.

This communication does not constitute an offer to sell any securities. Any such offer will be made only by means of a prospectus, pursuant to a registration statement filed with the Securities and Exchange Commission (the “SEC”).

In connection with the proposed Merger, a registration statement on Form S-4 (No. 333-191196) of Pioneer, which includes a proxy statement of the Partnership and constitutes a prospectus of Pioneer, was filed with the SEC by Pioneer on September 16, 2013, and amendments to such registration statement and the proxy statement/prospectus contained therein may be filed in the future. The registration statement has not yet been made effective by the SEC. Investors and security holders are urged to carefully read the documents filed with the SEC regarding the proposed Merger because they contain important information about Pioneer, the Partnership and the proposed Merger. Investors and security holders may obtain a free copy of the proxy statement/prospectus and other documents containing information about Pioneer and the Partnership, without charge, at the SEC’s website at www.sec.gov.

Pioneer, the Partnership and certain of the respective directors and executive officers of Pioneer and the General Partner may be deemed to be participants in the solicitation of proxies from the unitholders of the Partnership in connection with the proposed Merger. Information about the directors and executive officers of Pioneer is set forth in its proxy statement for its 2013 annual meeting of stockholders, which was filed with the SEC on April 11, 2013. Information about the directors and executive officers of the General Partner is set forth in the Partnership’s Annual Report on Form 10-K for the year ending December 31, 2012, which was filed with the SEC on March 14, 2013. These documents can be obtained without charge at the SEC’s website indicated above. Additional information regarding the interests of these participants may be obtained by reading the proxy statement/prospectus regarding the proposed Merger.

Except for historical information contained herein, the statements in this News Release are forward-looking statements that are made pursuant to the Safe Harbor Provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements and the business prospects of Pioneer Southwest are subject to a number of risks and uncertainties that may cause Pioneer Southwest’s actual results in future periods to differ materially from the forward-looking statements.These risks and uncertainties include, among other things, risks associated with the Merger Agreement, including the risks that the Merger will not be consummated and the anticipated benefits from the Merger cannot be fully realized, volatility of commodity prices, the effectiveness of Pioneer Southwest’s commodity price derivative strategy, reliance on Pioneer and its subsidiaries to manage Pioneer Southwest’s business and identify and evaluate drilling opportunities and acquisitions, product supply and demand, competition, the ability to obtain environmental and other permits and the timing thereof, other government regulation or action, the ability to obtain approvals from third parties and negotiate agreements with third parties on mutually acceptable terms, litigation, the costs and results of drilling and operations, availability of equipment, services, resources and personnel required to complete Pioneer Southwest’s operating activities, access to and availability of transportation, processing, fractionation and refining facilities, Pioneer Southwest’s ability to replace reserves, including through acquisitions, and implement its business plans or complete its development activities as scheduled, uncertainties associated with acquisitions, access to and cost of capital, the financial strength of counterparties to Pioneer Southwest’s credit facility and derivative contracts and the purchasers of Pioneer Southwest’s oil, NGL and gas production, uncertainties about estimates of reserves and the ability to add proved reserves in the future, the assumptions underlying production forecasts, quality of technical data and environmental and weather risks, including the possible impacts of climate change. These and other risks are described in Pioneer Southwest’s 10-K and 10-Q Reports and other filings with the SEC. In addition, Pioneer Southwest may be subject to currently unforeseen risks that may have a materially adverse impact on it. Pioneer Southwest undertakes no duty to publicly update these statements except as required by law.

PIONEER SOUTHWEST ENERGY PARTNERS L.P.
UNAUDITED SUPPLEMENTAL EARNINGS PER UNIT INFORMATION
(in thousands, except for per unit amounts)

The Partnership follows the two-class method of calculating basic and diluted net income per unit. Under the two-class method, generally accepted accounting principles ("GAAP") provide that net income be allocated to all securities that participate in the Partnership's earnings. Accordingly, net income is allocated to the General Partner, unvested participating securities and common unitholders. Net losses are allocated to the General Partner and common unitholders but only to unvested participating securities to the extent that they receive distributions during loss periods because unvested participating securities are not contractually obligated to share in the Partnership's net losses. Unit- and unit-based awards with guaranteed dividend or distribution participation rights qualify as "participating securities" during their vesting periods. The Partnership's basic and diluted net income per unit attributable to common unitholders is computed as (i) net income, (ii) less General Partner net income, (iii) less unvested participating securities' basic and diluted net income (iv) divided by weighted average basic and diluted units outstanding.

The following table provides a reconciliation of the Partnership's net income to basic and diluted net income attributable to common unitholders, and the calculation of net income per common unit - basic and diluted, for the three and nine months ended September 30, 2013 and 2012:

PIONEER SOUTHWEST ENERGY PARTNERS L.P.
UNAUDITED SUPPLEMENTAL NON-GAAP FINANCIAL MEASURES
(in thousands)

EBITDAX and distributable cash flow (as defined below) are presented herein and reconciled to the GAAP measures of net cash provided by operating activities and net income. Management of the General Partner believes these financial measures provide additional information to the investment community about the Partnership's ability to generate sufficient cash flow to sustain or increase distributions to its unitholders, among other items. In particular, EBITDAX is used in the Partnership's credit facility to determine the interest rate that the Partnership will pay on outstanding borrowings and to determine compliance with the leverage coverage test. EBITDAX and distributable cash flow should not be considered as alternatives to net cash provided by operating activities or net income, as defined by GAAP.

PIONEER SOUTHWEST ENERGY PARTNERS L.P.
UNAUDITED SUPPLEMENTAL INFORMATION

The following table summarizes net derivative gains and losses that the Partnership has recorded in its earnings for the three and nine months ended September 30, 2013:

PIONEER SOUTHWEST ENERGY PARTNERS L.P.
UNAUDITED SUPPLEMENTAL NON-GAAP FINANCIAL MEASURES
(in millions, except per unit data)

Adjusted income excluding unrealized mark-to-market derivative losses, as presented in this press release, is presented and reconciled to the Partnership’s net income determined in accordance with GAAP because the Partnership believes that this non-GAAP financial measure reflects an additional way of viewing aspects of the Partnership’s business that, when viewed together with its financial results computed in accordance with GAAP, provides a more complete understanding of factors and trends affecting its historical financial performance and future operating results, greater transparency of underlying trends and greater comparability of results across periods. In addition, management believes that this non-GAAP measure may enhance investors’ ability to assess the Partnership’s historical and future financial performance. This non-GAAP financial measure is not intended to be a substitute for the comparable GAAP measure and should be read only in conjunction with the Partnership’s consolidated financial statements prepared in accordance with GAAP. Unrealized mark-to-market derivative gains and losses will recur in future periods; however, the amount can vary significantly from period to period. The table below reconciles the Partnership’s net income for the three months ended September 30, 2013, as determined in accordance with GAAP, to adjusted income excluding unrealized mark-to-market derivative losses for that quarter.