The lessons of Equitrans’ storage well blowout are just starting to surface, as gas injection season nears

Pennsylvania gas storage operators and the agencies that oversee them are prepping for the fall injection season while the lessons of last fall’s massive blowout at a Cambria County Equitrans storage well are just trickling in.

This week, heavy equipment is back on the scene in Jackson Township, where Canonsburg-based Equitrans Midstream Corp. is resetting the cement plugs inside the troubled well deeper in the hole, so they can withstand the annual influx of natural gas stored at the Rager Mountain storage field for the winter.

But before it can pump the fuel into the ground, Equitrans needs permission from the federal Pipeline and Hazardous Materials Safety Administration, whose lead in the investigation and regulation of such storage wells has left state environmental officials unsure of their role.

“We’re still feeling around that right now,” Kurt Klapkowski, acting deputy secretary for the Pennsylvania Department of Environmental Protection’s office of oil and gas management, said during a meeting of the Oil and Gas Technical Advisory Board on Tuesday. “Trying to figure out where our jurisdiction ends or might be preempted by the federal government is something we’re looking at everyday as we move into that storage season.”

Mr. Klapkowski said last fall that the “catastrophic” leak at the Rager Mountain well would prompt a review and possible overhaul of how the DEP regulates and inspects such wells — there are more than 1,770 of them in the state, used to inject and withdraw natural gas from dozens of underground storage reservoirs.

So far, “no changes have been made on the regulatory side and no changes have been made in the field,” DEP spokeswoman Lauren Camarda said last week.

The company just recently completed a root cause analysis of what went wrong when the George L Reade 1 well at Rager Mountain suddenly burst open on Nov. 6 and spewed gas for nearly two weeks before it was finally brought under control. Equitrans sent a copy of the report to the DEP last week, and the agency said the document is confidential.

Corrosion is to blame

Publicly, Equitrans released a summary of the analysis which concluded that the problem was only 10 feet deep.

A short and wide metal pipe, which served as the outermost layer of protection for the well, had been thinning — corroding from the water and oxygen in the soil.

Last fall it ruptured, releasing nearly 1.2 billion cubic feet of gas.

The corrosion on the top joint was known to be there in 2016, the last time Equitrans ran a well logging tool through the hole and analyzed the findings. The analysis showed “limited” levels of corrosion that, in the company’s estimation, “did not require remedial action.”

In a more recent analysis of the same data after the rupture, using what Equitrans described as technology that was not available in 2016, the corrosion proved more severe, the company said.

Finding the difference stark, the company reanalyzed the logging records for 180 other storage wells using the new technology and while that identified “numerous disparities,” only two other wells warranted remediation, Equitrans spokeswoman Natalie Cox said. Those two have been temporarily plugged, she said.

Gas trapped in the ground

The company also slightly revised the amount of gas that had escaped during the event to 1.16 billion cubic feet and concluded that while the vast majority vented into the air, 127 million cubic feet escaped somewhere underground.

Based on where it was released and the type of formations that lay above and below that point, the company believes the rogue gas is trapped somewhere between 1,800 and 3,000 feet under the surface, in a sandstone layer sandwiched between two hard slabs of rock. That also happens to be the part of the well without cement around the pipe.

Before the rupture, Equitrans kept the vent on the well open to allow pressure pockets to be released. But that also allowed water, air and dirt to make their way into the annulus, which could have exacerbated the corrosion, the summary said.

The company said it performed “extensive field and laboratory soil and water well testing, which confirmed that no gas migrated to nearby residential areas.”

Some nearby landowners received water quality testing results last week.

Moving forward

Equitrans has replaced the damaged casing on the George L Reade 1 well but hasn’t yet decided if it might want to remove the temporary plugs from the well and continue to operate it, or plug it permanently. That decision, too, will need to be approved by federal pipeline regulators.

The company said it has evaluated all of its Rager Mountain wells — there are 10 storage wells and several observation wells there — and replaced the top joint casing on some “to proactively address less-aggressive corrosion.”

By the end of this year, Equitrans plans to complete updated diagnostics on about 100 wells. The company, which mostly operates pipeline infrastructure and is currently better known for building the Mountain Valley Pipeline, has about 300 storage wells in Pennsylvania.

State environmental regulators are still negotiating with Equitrans over the Rager Mountain incident after the company appealed three compliance orders issued to it by the DEP after the blowout. The most sweeping of those was withdrawn in April. The remaining two orders, which deal with surface issues like possible soil and water contamination from the “kill” fluid — heavy, briny liquid used to flood the well into submission — are still in litigation.

In late July, a judge with the Environmental Hearing Board granted the DEP and Equitrans more time to “conduct further sampling, review environmental data recently collected from the site,” and try to come to a settlement.

DEP inspection records show the agency has recently collected a number of water samples from nearby streams to test for possible contamination.