Attempts to plug Cambria well leak succesful

Methane had been venting from bore

It’s been two weeks since an Equitrans Midstream Corp. storage well began venting large volumes of methanein Cambria County.

Several attempts to “kill the well” by pumping heavy liquid from the top of the wellbore had failed. The Canonsburg-basedcompany said its contractors made another effort Saturday and appear to have “successfully flooded the well, stopped the flow of gas, and immediately beganplugging procedures.”

“In accordance with existing onsite safety protocols, crews will work 24/7 to monitor the well as they continue their efforts to permanently halt the venting,” Natalie Cox, a spokeswoman for the company, said ina Saturday evening update.

It’s still not known what caused the well to lose pressure and start venting an estimated 100 million cubic feet of natural gas per day.

The leak likely will result in major costs for Equitrans. If the preliminary leak rate estimate is accurate, the company has already lost

about $10 million in the value of gas alone — not counting the expense of trying to control the well, the disruption to operations during the beginning of cold weather, and whatever penalties might follow.

At Aliso Canyon in California, a much larger natural gas storage field where a well leaked for nearly four months and spewed an estimated 4.62 billion cubic feet of gas several years ago, there were seven attempts to “kill the well” by pumping heavy fluid from the top of the wellbore.

But those efforts, over the course of two months, didn’t succeed. When the company started to worry that applying too much pressure from the top could further damage the well,it drilled a relief well — a new conduit that intersected with the leaking well and allowed the operator to pump cement into the bottom of the troubled well. That ultimately worked and thewell was plugged in February 2016.

The California leak as well as the current leak at Rager Mountain in Cambria County came from a deep storage field under high pressure.

Neither the state Department of Environmental Protection nor Equitrans has disclosed what options are being considered if flooding the well from the top fails.

Ms. Cox reiterated that the company believes nearby residents are not in any danger, but that the company has offered to put people up in a hotel if they’d like. One landowner has accepted the offer.

The company and the DEP have officials stationed at the site 24 hours a day.

Once the well is plugged with cement, Equitrans will investigate the cause of the leak and conduct an environmental assessment of the Rager Mountain storage facility and areas nearby,according to a company update.

“Equitrans is committed to conducting a comprehensive fit-for-service analysis on all wells at the Rager Mountain storage facility prior to returning to full service,” the company said.

The DEP has asked the company to monitor for gas leaking underground.