Patterson-UTI Reports Drilling Activity for August 2008

PATTERSON-UTI ENERGY, INC. reported that for the month of August 2008, the Company had an average of 278 drilling rigs operating, including 265 rigs in the U.S. and 13 rigs in Canada. For the two months ended August 2008, the Company had an average of 273 drilling rigs operating, including 261 rigs in the U.S. and 12 rigs in Canada.

Average drilling rigs operating reported in the Company’s monthly announcements represent the average number of the Company’s drilling rigs that were moving or operating under a drilling contract. The Company cautioned that numerous factors in addition to average drilling rigs operating can impact the Company’s operating results and that a particular trend in the number of drilling rigs operating may or may not indicate a trend in or be indicative of the Company’s financial performance. The Company intends to continue providing monthly updates on drilling rigs operating shortly after the end of each month.

Patterson-UTI Energy, Inc. provides onshore contract drilling services to exploration and production companies in North America. The Company has approximately 350 currently marketable land-based drilling rigs that operate primarily in the oil and natural gas producing regions of Texas, New Mexico, Oklahoma, Arkansas, Louisiana, Mississippi, Alabama, Colorado, Utah, Wyoming, Montana, North Dakota, South Dakota, Pennsylvania and western Canada. Patterson-UTI Energy, Inc. is also engaged in the businesses of pressure pumping services and drilling and completion fluid services. Additionally, the Company has an exploration and production business.