HOUSTON, Jan. 3 (Xinhua) -- The number of active drilling rigs in the United States decreased by nine to 796 this week, down by 279 rigs year-on-year, according to weekly data released by a Houston-based oilfield services company on Friday.
According to Baker Hughes, these active drilling rigs included 670 oil rigs operating in the U.S. oil fields, down by seven from the previous week; 123 gas drilling rigs, down by two from the previous week; and three miscellaneous rigs, unchanged from last week.
The 796 rigs include 773 land drilling rigs, down by eight from the previous week; 22 offshore drilling rigs, down by one; and one inland waters drilling rig which remained unchanged from last week.
Of them, 51 are directional drilling rigs, 701 are horizontal drilling rigs and 44 are vertical drilling rigs.
During the week, the states of New Mexico, Oklahoma, Pennsylvania, Texas and Wyoming all saw a decline in drilling rigs by one, while Alaska is the only state seeing an increase by one to eight rigs.
The number of directional and horizontal drilling rigs in the country both decreased by two this week and were respectively down 15 and 244 year-on-year. The count of vertical rigs decreased by five and was down 20 year-on-year.
By far, the Permian Basin in western Texas and eastern New Mexico has been the largest source of shale oil production growth in the United States, having become an engine of supply growth outside the Organization of the Petroleum Exporting Countries in the past years.
