Anadarko reports gains at four U.S. drill sites HOUSTON, Dec. 5 (UPI) -- More than 100,000 barrels of oil equivalent per day have come from four key U.S. onshore developments, Anadarko Petroleum Corp. said. "Surpassing the milestone of 100,000 boe per day in four of our core U.S. onshore operating areas demonstrates the quality, capabilities and increasing scale of Anadarko's portfolio," Anadarko President and Chief Executive Officer Al Walker said in a statement. The company said production came from the Eagle Ford shale play in Texas, the Marcellus shale play in Pennsylvania, the Greater Natural Buttes area in Utah and the Wattenberg field in Colorado. Anadarko said it's horizontal drilling program set a gross production record of 45,000 boe per day at Wattenberg. The company said sales there are expected to grow 10 percent compared to the third quarter of the year. In May, U.S. Interior Secretary Ken Salazar signed a record of decision for the Greater Natural Buttes project proposed by Anadarko. Salazar approved the development of 3,675 natural gas wells in an existing gas producing area in Uintah County. Eagle Ford and Marcellus are among the largest shale resource areas in the United States.