HOUSTON, Dec. 13 (Xinhua) -- The number of active drilling rigs in the United States stands at 589 this week, unchanged from the previous week but down by 34 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 the U.S. oil fields, the same as last week; 103 gas drilling rigs, up by one
