Twelve days after an explosion and fire at a Marcellus Shale gas well in Dunkard, Greene County, workers are expected to begin capping two damaged wellheads.
Workers prepared Saturday for capping the first well today, said Kelly Burch, executive director of oil and gas operations for the state Department of Environmental Protection. That is expected to be followed by preparations on Monday and installation of the second cap Tuesday.
A Feb. 11 explosion killed Ian McKee, 27, an employee of Cameron International who was working on the site, and a fire burned for about five days before dying out. The cause of the explosion has not been determined, Mr. Burch said. The fire took place in one well but was directed at a 90-degree angle, damaging a wellhead 20 to 30 feet away, he said.
Once the caps are installed, Mr. Burch said, "The site will be secure. The safety concerns will go away."
Chevron, which owns the wells, hasn't made a decision about the future of the wells, he said, but whatever is decided, more work will have to be done after Tuesday.
The company conducted pressure tests Friday on both wells and found that the integrity of the wells to hold pressure has not been compromised, Mr. Burch said.
"I think the next couple of days are critical. The positive results [Friday] were very welcome news so they could proceed according to schedule without having to do any further remedial activities on the well."
Workers are expected to use an abrasive jet cutter -- which operates with sand and high-pressure water -- to cut off the damaged wellhead on the first one, Mr. Burch said. There is a 180-ton crane on hand for installing a new cap, which is 8 to 10 feet tall.
While the wells were not yet in production when the fire occurred, the old wellhead was designed for production. The new caps will secure the wells.
Chevron said in a news release that the capping and cutting work are planned to take place during daylight hours but might extend into the night. The section of the wellhead where the leak took place will be taken for independent analysis, Chevron said.
Once the two wells are capped, Chevron said its contractor, Wild Well Control, will check a third well and make any needed repairs. After that, the gas flow for the three wells will be stopped.
Other work to be done includes installing plugs as protective barriers about 8,000 feet below the surface in all three wells so that gas pressure does not reach the wellhead. This procedure is expected to take about four days per well. Portions of the work may involve flaring of gas, Chevron said.
"These well intervention efforts involve many steps and will be executed in a precise, controlled, and methodical manner," Chevron said. "We are striving to be efficient in our efforts to minimize the duration of the operations, however, the safety of the workers and operations will determine the appropriate pace."
Lexi Belculfine contributed. Eleanor Chute: email@example.com or 412-263-1955. First Published February 22, 2014 1:36 PM