Explorers added oil rigs in the U.S. for a sixth consecutive week after OPEC’s pledge to cut output triggered a crude market rally, allowing producers to lock in higher prices with hedge contracts. Rigs targeting crude in the U.S. rose by 3 to 428, adding to the largest level of work since February. Producers haven’t pulled back activity since the end of June. Natural gas rigs fell by 2 to 94 this week, while miscellaneous rigs rose by 1 to 2, bringing the total for oil and gas up by 2 to 524. Despite the overall activity boost, none of the four largest oil basins added rigs. “Companies are looking at areas that are under-explored or under-developed,” James Williams, president of WTRG Economics in London, Arkansas, said Friday in a phone interview. “But what we’re going to see is continued growth in the major oil plays.” Oil breached $50 […]