Patterson-UTI Underscores Drilling Activity for July 2009

Patterson-UTI Energy has reported that for the month of July 2009, the Company had an average of 65 drilling rigs operating, including 63 rigs in the United States and 2 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 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.