Pennsylvania environmental officials on Monday suspended some operations of a Marcellus Shale natural gas operator whose well blew out last week and spewed natural gas and 35,000 gallons of drilling fluid in a remote part of Clearfield County.
Department of Environmental Protection Secretary John Hanger ordered EOG Resources Inc. to suspend its natural-gas well drilling activities in Pennsylvania until DEP has completed a comprehensive investigation into the leak and the company has implemented any needed changes.
"The Clearfield County incident presented a serious threat to life and property," said Hanger. "We are working with the company to review its Pennsylvania drilling operations fully from beginning to end to ensure an incident of this nature does not happen again."
Investigators said they don't know what caused the well to erupt nor why a mechanical safety device failed to prevent the blowout.
Elizabeth Ivers, a spokeswoman for EOG the Houston company was called Enron Oil and Gas until 1999 said it was formulating a response to the state's action.
"We are very concerned about what happened here and we're not relying on the company to tell us what went wrong," Gov. Rendell said Monday afternoon at a news conference.
DEP inspectors and environmental consultants hired by EOG scurried to erect trenches and collection systems this weekend to sop up the liquids expelled when the well erupted in a 75-foot-tall geyser of natural gas and drilling fluid.
Neil Weaver, a DEP spokesman, said fluids and natural gas escaped in the 16 hours that the well gushed before a containment team sent in from Texas was able to stop the flow on Friday. EOG on Monday estimated that 35,000 gallons of fluid spilled on the ground.
There were no injuries in the accident, and the gas did not ignite. The nearest residence is about a mile from the site, DEP said.
Weaver said Monday that none of the fluid that shot out of the well on the Punxsutawney Hunting Club in Lawrence Township flowed into surface streams.
But inspectors are monitoring the spill to determine whether any chemicals used in hydraulic fracturing - the process known as "fracking" - seeped through the soil into underground water supplies.
"Our preliminary assessment of the damage done to the environment appears modest as the frack fluid was contained and did not appear to reach any streams," Weaver said.
Weaver said that a spring in the area showed "a spike in conductivity," an indication of potential seepage of salty brine from the spill. He said EOG had collected the discharge.
Weaver said DEP is continuing to monitor the situation "because sometimes the impacts of a large spill like this are delayed as the material travels through groundwater."
Investigators are uncertain what caused the blowout.
The monthlong drilling operation ended on March 3. Contractors returned in May to hydraulically fracture the well over 12 days. The process involves the injection of water, sand and chemicals under high pressure to shatter the gas-bearing rock so that the fuel can be recovered.
The frack job ended on May 28. The operator had begun well-completion operations on June 1. The blowout occurred two days later.
High pressure in an oil or gas well is both desired and essential - the pressure is what brings the fuel to the surface. Blowouts occur when the pressure surges and overwhelms control mechanisms.
A device known as a blowout preventer is attached to the wellhead at the surface. It is designed to be triggered by operators to control pressure surges.
"Our preliminary investigation found there was a failure to the blowout preventer," the DEP's Weaver said Monday. "The blowout preventer did not function properly. If it had, there would not have been a blowout. The company also confirmed that the blowout preventer failed."
The failure of a blowout preventer led to the explosion of BP's Deep Horizon well in the Gulf of Mexico in April, which has spilled millions of gallons of crude oil into the gulf.
Though the industry says blowouts are rare, another natural gas well, in West Virginia, blew up on Monday, burning seven workers.
A crew drilling a natural gas well through an abandoned coal mine in the state's northern panhandle hit a pocket of methane gas that somehow ignited, West Virginia inspectors said.
The blast created a column of flame at least 70 feet high, and it will likely burn until a team of well-fire experts can reach the scene to extinguish it, said Bill Hendershot, an inspector with the Department of Environmental Protection's Office of Oil and Gas.
The fire is in a rural area outside Moundsville, about 55 miles southwest of Pittsburgh, and presents no danger to any structures or people, Hendershot said.
Contact staff writer Andrew Maykuth at 215-854-2947 or firstname.lastname@example.org.
Inquirer staff writer Amy Worden contributed to this article.
This article contains information from the Associated Press.