Anadarko has been given approval to launch an increased density drilling project, expanding operations from one natural gas well every 40 acres to one well every 10 acres. The new spacing variance project is the first approved by the Utah Division of Oil, Gas and Mining and is possible through "directional" or non-vertical drilling.
"This project milestone allows us to effectively recover more of the resources, while at the same time avoid overdrilling, which could lead to two wells competing for the same natural gas reserves," said Brad Miller, general manager for Anadarko's Greater Natural Buttes Field in Uintah County.
Directional drilling, combined with approval to drill wells on 10-acre spacing, will enable the company to produce more domestic energy resources. To minimize surface disturbance, Anadarko plans to utilize directional drilling technology to drill four wells from locations previously used to drill wells spaced 40 acres apart.
"If we drill four wells on a pad, the cycle time is much more efficient," said Miller. "It's a very exciting development."
Gas gathering wells run parallel beneath the ground to a certain depth, then spread out like fans to reach productive areas previously inaccessible through traditional vertical drilling.
"Evidence showed if they didn't drill wells that dense there would be natural gas reserves left in the ground," said Gil Hunt, associate director for the Division of Oil, Gas and Mining.
"Prior to approaching the board with our spacing request, Anadarko spent years conducting research to provide proof that density drilling would yield the results predicted," said Scott Gamble, development evaluation manager for Anadarko.
The increased density drilling project will be conducted entirely in Uintah County on contiguous acreage in the South Canyon and Hatch areas of the Natural Buttes field on federal, state and private land. The wells will be drilled to depths of up to 11,000 feet within the Wasatch and Mesaverde formations.
Because the wellheads can be placed on the same drilling pad, it means fewer rig moves, less truck traffic and less environmental impact.
"We call this a 'brown' field," said Miller, "which means it already has locations and roads in place."
Utilization of existing well pads will have one-tenth the disturbance of building new locations for vertical wells.
Anadarko the largest natural gas producer in Utah is committed to drill 200 natural gas wells in Uintah County this year alone.
Miller said that in 2009, plans call for increasing the current rig count from eight to 12 so that 300 wells can be drilled. In 2010, 15 rigs would drill 400 wells.
"It's cheaper to drill a vertical hole," said Hunt, adding that directional drilling still holds a trump because of the time it saves. "It's more expensive, it requires more technology and more people to run it, but I think companies are weighing that against long environmental impact expense of drilling vertically."
Uintah County is the state's top producer of natural gas. Last year Utah's 4,700 natural gas wells produced 385 billion cubic feet of natural gas Anadarko produced approximately 90 billion cubic feet of natural gas equivalent in the state, according to Miller.
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