Concerns Raised on Intersection of Underground Wells
In West Virginia's natural gas boom, a potential concern is what might happen when the maze of underground wells intersect.
There have been three documented cases of deep Marcellus drilling and high-pressure fracking connecting with older wells. Given the hundreds of thousands of wells, said Jim O'Reilly, an expert in regulation and liability at the University of Cincinnati, it's likely there are more problems no one knows about that could be more frequent in the future.
O'Reilly said a lot depends on the stability of underground concrete well casings.
"Anyone that's walked on a crumbling sidewalk realizes that concrete has a life," he said. "It may be a matter of a year, it may be several years - but inevitably, the concrete in the wells will fail."
There are countless private water wells, and 2,000 Marcellus gas permits. The industry says fracking takes place thousands of feet below these other wells. Gene Smith, assistant chief of permitting at the West Virginia Department of Environmental Protection's Office of Oil and Gas, said that normally keeps the wells from affecting each other.
A more common issue, Smith said, is a gas well disrupting - but not contaminating - an aquifer at a few hundred feet below ground.
"Any time you drill through that aquifer - which we do - there could be a disruption in water quality and quantity for a certain amount of time, until that aquifer revives from that shock of being drilled through," he said.
Smith admitted that his department is badly understaffed, with 17 inspectors in the field, charged with monitoring the hundreds of thousands of wells. O'Reilly agreed that's an issue.
"Ideally, all of the state and federal regulators are doing their jobs perfectly," he said. "I just wish there were more of them."
According to the West Virginia Geological and Economic Survey, the industry has drilled more than 150,000 oil and gas wells in the state.
The industry and state regulators contend that a properly constructed well casing should keep the pressure from the Marcellus wells from traveling along natural cracks in the rocks and connecting with other wells.