HOUSTON, Aug. 5 (Xinhua) -- The number of active drilling rigs in the United States stood at 764 this week, down by three from the previous week and 273 from one year ago, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes.
These active drilling rigs included 598 oil rigs operating in the U.S. oil fields, down by seven from the previous week; 161 gas drilling rigs, up by four from last week; and five miscellaneous rigs, unchanged from last week.
The rigs included 746 land drilling rigs, two inland water rigs, and 16 offshore drilling rigs.
Of them, 37 are directional drilling rigs, 698 are horizontal drilling rigs and 29 are vertical drilling rigs.
The Permian Basin in western Texas and eastern New Mexico has been the largest source of shale oil production growth in the United States, and an engine of supply growth outside the Organization of the Petroleum Exporting Countries in the past years.