I was disturbed that the Times Union would print such a factually misleading commentary about alleged leaking gas wells. Josh Fox and Barbara Arrindell in "Fracking is hardly leakproof," June 20, state groundwater protection is simply a single 1-inch thick layer of cement between the formation and the steel casing. As a practicing geologist and petroleum engineer for more than 30 years, I can tell you this is completely incorrect.
While minimum cemented space between the casing and the rock (annulus) varies by state and conditions, it is common practice in shale gas wells to drill a 17 ½-inch surface hole and install 13 3/8 casing past the base of the groundwater, leaving a 4 1/8-inch cemented space.
Surface casing is fully cemented to the surface, centralizers are placed every 120 feet to keep the pipe centered during cementing, and then both the casing and cement are pressure-tested to ensure integrity. Likewise, as the well is deepened, overlapping intermediate and production casing are eventually run and cemented to the surface.
At least three full layers of casing and thick, highly engineered cement protect the groundwater sources. Pressure is continually monitored for any leakage. It is not surprising that gas leaks are actually infrequent, typically inconsequential and fixable, as the state Department of Environmental Conservation can attest.
Propaganda continues to deny New Yorkers the immense economic and environmental benefits of clean-burning natural gas, not to mention the opportunity to eliminate acid rain in the Adirondacks primarily caused by coal-fired power plants.
Scott Cline
Stanley, Ontario County