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Oregon Gas Drilling: Different Challenges Between Sandstone and Coal Beds

July 31, 2011 | OPB
CONTRIBUTED BY:
Bonnie Stewart


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  • Conventional gas is considered relatively easy to extract because it is in porous sandstone, rather than tight sandstone, shale or coal-bed reservoirs. credit: U.S. Energy Information Administration and U.S. Geological Survey
  • Coal bed gas near Coos Bay and other parts of the lower 48 states. credit: U.S. Energy Information Administration
Conventional gas is considered relatively easy to extract because it is in porous sandstone, rather than tight sandstone, shale or coal-bed reservoirs. | credit: U.S. Energy Information Administration and U.S. Geological Survey | rollover image for more

Hydraulic fracturing hasn’t been necessary for the region’s only operating gas wells, located in northwestern Oregon. But it’s another story near the state’s southern coast.

Oregon’s Mist Gas Field wells, like those in Idaho, tap into porous sandstone that releases gas without hydraulic fracturing, or “fracking,” says Bob Houston, a top official with the state’s Department of Geology and Mineral Industries, or DOGAMI for short.

Located in a relatively remote area of Columbia County, the wells have been producing gas for decades, beginning in the 1980s. They were drilled vertically and sometimes at an angle to extend a gas pipe’s reach into the sandstone. Once the pipe hits its target, the gas moves through the porous sand without fracking.

More in This Report

  • An overview of Northwest gas drilling, with video, audio, photos and an interactive map.

  • A closer look at gas well activity in Idaho and Washington.

Enerfin Resources Northwest operates 25 Mist wells, and NW Natural pumps gas from four wells there. Neither company has violated state laws, says DOGAMI’s Houston.

NW Natural, a natural gas distributor, also stores gas in the Mist Field, injecting the fuel into previously drained wells.

The Mist Field injection wells are permitted by the state and none has had a violation, says Rodney Weick, water quality manager for the Oregon Department of Environmental Quality’s northwest region. The wells’ 10-year injection permit, however, expired in 2009, and has not been renewed because the DEQ has fallen behind on that work. A draft permit should soon be ready for the company to review, Weick says.

No one has filed a formal complaint about the wells in the 12 years Cynthia Zemaitis has been the county’s natural resources administrator. Landowners, though, have complained that they aren’t paid enough for their mineral rights, she says.

The county owns some of the gas land and, in 2010, earned more than $1 million from leases and royalties.

In Southwest Oregon, however, the story is different because the geology is different.

Like many wells in Colorado, Montana and Wyoming, Coos County wells tap gas in coal beds, not sandstone. A few Coos County wells already have been drilled and fracked and likely will be fracked again if they are reopened for production.

Drilled in 2005 and 2006, the wells have been in limbo since 2008, when the economy crashed and the original leaseholder filed for bankruptcy. Some still hope the wells will attract investors. Others fear the state is not equipped to regulate coal-bed gas operations.

In 2005, North Bend resident Ron Sadler alerted top state officials to the effect the drilling might have on water resources, salmon and steelhead.

Sadler, the former Chief of Forestry Planning for the federal Bureau of Land Management in Oregon and Washington, contacted officials again in 2007, when he learned Halliburton Energy Services had fracked four wells 16 times by injecting a highly pressurized mix of nitrogen, water and possibly other ingredients to force the gas from the coal.

Later, five additional wells were fracked, and they still hold production promise, says Ron Robinson, the Coos Bay operations manager for Westport Energy, which now holds the well permits.

Robinson says he is the only person on the payroll in Oregon, but that could change. The Westport wells are located relatively close to a pipeline, and Robinson says the gas is better than anything coming out of Canada because it is “sweet,” which means it is low moisture, high BTU gas.

Another out-of-state company has made inquiries about the wells and permitting process, say state officials, but the wells still are on hold.

If the wells shift to production, they’ll have to be “dewatered,” which would resurrect the groundwater issue.

“Fifty percent of a coal bed methane project is producing gas; the other 50 percent is dealing with water,” Robinson says.

Sadler fears that removing the water will diminish the area aquifers and alter stream flow patterns, thus disrupting the spawning and rearing habitat of salmonid populations.

Disposing of the extracted water brings its own set of problems.

Before Methane Energy filed for bankruptcy, it received a permit to discharge 100,000 gallons of pretreated water each day into the Davis Slough. That much water would fill about two large in-ground swimming pools.

In issuing the permit, officials relied upon the 2004 U.S. Environmental Protection Agency study that concluded fracking would not contaminate groundwater. That study’s conclusions have been challenged repeatedly in the past few years. In fact, because of numerous recent reports of groundwater contamination, the EPA is conducting a new fracking study.

Originally, Methane Energy’s long-term plan was to drill 300 gas wells on more than 100,000 acres it had leased from public and private landowners. Those leases, considered an asset, now belong to Westport Energy.

If the company shifts into production mode, it will need about a dozen employees, and finding them locally would not be a problem, Robinson says.

“The skill sets in the local community are good,” he says.

Initially, he estimates, the restart could pump about $300,000 into the economy.

© 2011 OPB
Mist Field Oregon Coos Bay hydraulic fracturing fracking natural gas drilling
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