ENERGY

Oil, Gas Rig Count Jumps by 31: The number of working oil and gas rigs in the United States jumped by 31 this week to 787, Baker Hughes Inc. said. The tally also neared last year’s high mark of 796, the Houston tool maker said. Last week, the count climbed by one to 756. The rig count is the widely watched index of domestic drilling activity. It represents the number of rigs actively exploring for--not producing--oil and natural gas. Baker Hughes has kept track of the count since 1940. The count peaked at 4,500 in December, 1981, during the oil boom. This summer, the count dropped to a record low of 596.