HOUSTON, July 21 (Xinhua) -- The number of active drilling rigs in the United States fell to 669 this week, down by six from the previous week and by 89 from this time last year, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes.
These active drilling rigs included 530 oil rigs operating in the U.S. oil fields, down by seven from the previous week; 131 gas drilling rigs, down by two from last week; and eight miscellaneous rigs, up by three from last week.
The rigs included 647 land drilling rigs, four inland water rigs, and 18 offshore drilling rigs.
Of them, 51 are directional drilling rigs, 600 are horizontal drilling rigs and 18 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.
