The number of rigs exploring for oil and natural gas in the U.S. increased by five this week to 511.
A year ago, 838 rigs were active. Depressed energy prices have sharply curtailed oil and gas exploration.
Houston oilfield services company Baker Hughes Inc. said Friday that 418 rigs sought oil and 92 explored for natural gas this week. One was listed as miscellaneous.
Among major oil- and gas-producing states, Texas and Oklahoma each gained two rigs and Alaska, California, North Dakota and Pennsylvania each was up one.
Louisiana, New Mexico and West Virginia each declined by one rig.
Arkansas, Colorado, Kansas, Ohio, Utah and Wyoming were unchanged.
The U.S. rig count peaked at 4,530 in 1981. It bottomed out in May at 404.
