HOUSTON, March 22 (Xinhua) -- The number of active drilling rigs in the United States decreased to 624 this week, down by five from the previous week and down by 134 from one year ago, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes.
These active drilling rigs included 509 oil rigs operating in the U.S. oil fields, down by one from the previous week; 112 gas drilling rigs, down by four from last week; and three miscellaneous rigs, the same as last week.
The rigs included 601 land drilling rigs, zero inland water rigs, and 23 offshore drilling rigs.
Of them, 56 are directional drilling rigs, 556 are horizontal drilling rigs and 12 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.
