The Houston firm said Friday 510 rigs sought oil and 127 explored for natural gas amid depressed energy prices. A year ago, 1,633 rigs were active.
Among major oil- and gas-producing states, Texas declined by seven rigs, Pennsylvania was down three, Kansas, New Mexico and North Dakota dropped two each and California was off one.
Alaska increased by two rigs and Ohio was up one.
Arkansas, Colorado, Louisiana, Oklahoma, Utah, West Virginia and Wyoming were all unchanged.
The U.S. rig count peaked at 4,530 in 1981 and bottomed at 488 in 1999.