The number of rigs drilling for oil in the U.S. climbed four in the past week to 432, continuing a trend of increases, according to oil-field services company Baker Hughes Inc. BHI -1.41 % The U.S. oil-rig count is typically viewed as a proxy for activity in the sector. After peaking at 1,609 in October 2014, low oil prices put downward pressure on production and the rig count fell sharply. The oil rig count has generally been rising since the beginning of the summer. The nation’s gas-rig count jumped 11 to 105 in the past week. The U.S. offshore-rig count was unchanged at 23, which is down 10 from a year ago. On Friday, crude oil prices wavered between gains and losses, on concerns about persistently high global oil supplies. “We need some other kind of bullish factor to get a sustained move from here,” said Tariq Zahir, managing […]