HOUSTON, Dec. 6 (Xinhua) -- The number of active drilling rigs in the United States rose to 589 this week, up by seven from the previous week but down by 37 from a year ago, according to the weekly data released Friday by Houston-based oilfield services company Baker Hughes.
These active drilling rigs include 482 oil rigs operating in U.S. oil fields, up by five from the previous week; 102 gas drilling rigs, up
