Oil giant BP is moving its U.S. onshore oil and gas headquarters from Houston to Denver, and taking about 200 of its 4,500 local employees with it. The new Colorado office, the company said on Wednesday, will be closer to its operations in the Rocky Mountains, "an important energy hub of the future."

Two-thirds of BP's oil and gas production and proved reserves are in the Rockies, the company said. It still has operations in east and south Texas, but it sold most of its land in west Texas' prolific Permian Basin about five years ago.

Meanwhile, the company has added acreage in Wyoming and in the San Juan Basin, which stretches from southern Colorado to northern New Mexico.

"We have a vast, vast position in the Rockies," said David Lawler, CEO of BP Lower 48. He called Denver a logical and strategic fit for the business, and lauded the new headquarters' proximity to world-class universities, industry expertise and Rocky Mountain operations.

The move is part of a shift in BP strategy. In the late 2000s, smaller, independent drillers began discovering vast volumes of oil and gas in U.S. shale fields like south Texas' Eagle Ford and Fort Worth's Barnett. But the big oil companies, like Exxon and BP, were slow to adapt and struggled to pick up good acreage in key fields.

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In 2010, BP even sold 10 fields and two gas processing plants in the Permian Basin to Houston-based Apache Corp. for $7 billion, part of an effort to help pay cleanup costs and damages from the Deepwater Horizon oil spill in the Gulf of Mexico.

By 2014, BP executives knew they had to operate their exploration and production division differently. They hired Lawler away from independent Oklahoma City oil and gas production company Sandridge Energy, separated U.S. Lower 48 operations as a stand-alone business, and embraced new shale drilling and well completion techniques.

In 2015, BP bought all of Oklahoma City explorer Devon Energy's assets in the San Juan Basin, adding nearly 15,000 net acres to its portfolio. That year, it completed its first San Juan "multilateral" well, which digs multiple horizontal shafts connected to a single vertical wellbore, accessing more oil and gas via fewer drilling sites.

BP's U.S. Lower 48 onshore operations now span five states — Colorado, New Mexico, Oklahoma, Texas and Wyoming — and 6 million net acres, an area roughly the size of Vermont, with 7.5 billion barrels of oil and gas in the ground. The division pumps about 300,000 barrels of oil equivalent each day.

About 30 percent of the unit's production comes from the San Juan. The company's operations in the basin are based out of Durango, Colo., and Farmington, N.M.

BP has leased office space is in the Lower Highlands district near downtown Denver. The company anticipates the office will open with at least 200 employees, largely from Houston, including the CEO and executive leadership team, with more staff to be added later.

BP's onshore oil and gas division has about 450 workers in Houston now. Houston also houses about 4,000 additional BP employees in the company's Gulf of Mexico, natural gas, wind, and upstream technology groups. BP has about 15,000 employees stationed in various U.S. locations, from Texas wind farms to an Indiana refinery to Alaskan oil fields.

"Houston will remain a large and important center for our business, and we have no plans to change that," Lawler said. Those being transferred to Denver are already doing a significant amount of their work there. Their absence won't affect Houston much, he said, and should save BP commuting time and money.

The division's move isn't about Texas oil fields, Lawler said. "This is a step to get closer to the assets we have," he said. "This was a portfolio decision for us."

BP expects the Denver office to open in the first quarter of 2018.