Wednesday, June 25, 2008

OGAP Report on the Marcellus Shale

The Oil and Gas Accountability Project, a Colorado-based environmental organization dedicated to reducing the impacts of oil and gas development, has released a new report on Marcellus shale drilling.

The report provides helpful information on the size, depth, location and geology of the shale, as well as basics on horizontal and vertical drilling and the cost to develop different types of wells. But the report is most provocative-- and takes its most direct advocacy stance-- in its sections on hydraulic fracturing, naturally occurring radioactive materials (NORMs), metals, hydrogen sulfide and well spacing.

For example, the report sites Schlumberger, an oil and gas service company, and representatives from Range Resources and Cabot Oil and Gas saying that slickwater, a type of hydraulic fracturing fluid that requires "much more water than a typical sand and water frac," may be more effective at fracturing high-pressure areas of the shale than nitrogen gas or nitrogen foam.

"If this is the case," the report notes, "then landowners in the overpressured regions in the northern part of the play [which includes Northeastern Pennsylvania] can expect to see a lot more water truck activity than landowners in the southern part of the Marcellus shale."

The report devotes several sections to the amount of water that may be needed to explore the shale. It notes that "a well drilled in the Marcellus shale may have to be fracked several times over the course of its life to keep the gas flowing, and that each fracking operation may require more water than the previous one."

The report recommends that Pennsylvania study the radioactive material that may be in the waste produced from Marcellus wells (a process that has already been started, according to comments by Ronald Gilius, the head of the state Bureau of Oil and Gas Management, at an operators summit in Harrisburg earlier this month). The report points out that Pennsylvania does not have specific oil and gas regulations that pertain to NORMs, but other states, including Texas and New Mexico, do.

This may be a concern, OGAP notes, because the Marcellus shale is considered to be relatively more radioactive than other geological formations. The report cites a 1992 study of the radioactivity of the shale where it approaches the surface in Onondaga County, N.Y., which showed that the average amount of radon found in homes underlain by Marcellus shale was more than twice the U.S. Environmental Protection Agency's "action level"-- "the level when it is recommended that homeowners try to reduce the radon."

The OGAP report is based primarily on information drawn from other gas shales where more exploration has been done, like the Barnett Shale in Texas, but OGAP cautions readers "not to assume that what has occurred in any other gas shale basin will necessarily occur in the Marcellus shale." Most of the data is compiled from news reports, oil and gas trade publications, and scientific studies.