Pioneer Natural Resources Company (NYSE:PXD) today announced a significant discovery in the Eagle Ford Shale in South Texas. The Sinor #5 well, which is located in Live Oak County, Texas, flowed at an initial rate of approximately 11.3 million cubic feet of natural gas equivalent per day (approximately 8.3 million cubic feet of natural gas per day and 500 barrels of condensate per day) on a 22/64 inch choke with 4,550 pounds per square inch wellhead flowing pressure. The liquids-rich gas contains 1,200 British thermal units per cubic foot. The well was drilled to a true vertical depth of approximately 13,000 feet and completed in a 2,600-foot lateral section with a nine-stage fracture stimulation (frac). The well is currently producing to sales.

Scott Sheffield, Chairman and CEO, stated, “The initial results of the Sinor #5 discovery are very encouraging, especially considering the significant volume of higher-valued condensate and natural gas liquids. This discovery, coupled with the Eagle Ford Shale wells recently completed by others, reinforces our expectation that this shale play will be very prolific. Our South Texas team has extensive experience drilling horizontal wells in the Edwards formation, which lies directly below the Eagle Ford formation. When combined with our greater than 2,000 square miles of 3-D seismic data, logs from more than 150 operated wells, proprietary core samples and existing infrastructure, we are confident in our ability to unlock the significant resource potential contained within our 310,000 gross acres in the play.”

The Sinor #5 well is the first of a five-well program initiated by Pioneer in August to assess the resource potential across the Company’s Eagle Ford acreage. Pioneer now plans to expand the five-well program by continuously operating one rig in the play through 2010 and will evaluate a further expansion as additional drilling results become known. The Company has spud its second well and expects to test the benefits of longer laterals and additional frac stages going forward.

Pioneer is a large independent oil and gas exploration and production company, headquartered in Dallas, with operations in the United States, South Africa and Tunisia. For more information, visit Pioneer’s website at www.pxd.com.

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 are subject to a number of risks and uncertainties that may cause Pioneer’s actual results in future periods to differ materially from the forward-looking statements. These risks and uncertainties include, among other things, volatility of commodity prices, 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, access to and availability of drilling equipment and transportation, processing and refining facilities, Pioneer's ability to implement its business plans or complete its development projects as scheduled, access to and cost of capital, quality of technical data, and environmental and weather risks. These and other risks are described in Pioneer’s 10-K and 10-Q Reports and other filings with the Securities and Exchange Commission. In addition, Pioneer may be subject to currently unforeseen risks that may have a materially adverse impact on it. Pioneer undertakes no duty to publicly update these statements except as required by law.