Source : Charleston Daily Mail
FRAMETOWN, W.Va. (AP) Eight small earthquakes in central West Virginia since April have Chesapeake Energy and the state Department of Environmental Protection discussing the possibility of seismic monitoring near a disposal well for gas-drilling fluids.
Oklahoma-based Chesapeake has injected more than 10.6 million gallons of brine and hydraulic fracturing fluid into the well since March 2009. The underground injection site in the Frametown area has been a permitted disposal well since 2008.
Some geologists suspect high pressure and wastewater have lubricated old fault lines, allowing them to slip and trigger small earthquakes. Chesapeake isn’t so sure, but it has agreed to reduce the volume of fluid it’s injecting.
Gene Smith, compliance manager for the DEP, said no link has been proven, and no seismic events have been reported at 70 similar disposal wells around West Virginia. Still, he said, the state will investigate.
“We’re looking at the mechanics of the well, the geology of the area and the events that have been happening in the area, to see, from a scientific level, if what’s taking place could cause earthquakes,” Smith said.
Since April 4, Braxton County has been shaken by eight small earthquakes registering between 2.2 and 3.4 on the Richter scale. No major damage was reported.
Drilling companies are producing wastewater as they rush to tap the Marcellus shale field, a rich natural gas reserve that underlies Ohio, West Virginia, Pennsylvania and New York. The gas is locked in tightly compacted rock a mile underground, and freeing it requires unconventional horizontal drilling technologies and vast amounts of water.
The DEP says many companies are recycling much of their water, but some is also pumped back into storage wells.