HOUSTON, March 15 (Xinhua) -- The number of active drilling rigs in the United States increased to 629 this week, up by seven from the previous week but down by 125 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 510 oil rigs operating in the U.S. oil fields, up by six from the previous week; 116 gas drilling rigs, up by one from last week; and three miscellaneous rigs, the same as last week.
The rigs included 605 land drilling rigs, zero inland water rigs, and 24 offshore drilling rigs.
Of them, 54 are directional drilling rigs, 562 are horizontal drilling rigs and 13 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.
