Apache Corp. evacuated 15 workers from a drilling rig in the Gulf of Mexico and is preparing kill the well after tests found natural gas migrating below the seabed.
The Houston-based company has contracted with specialists Boots & Coots to kill the natural gas well, located in 218 feet of water about 50 miles east of Venice, La. A drilling rig is heading for the site in case it’s needed to bore a relief well to intercept the one being plugged.
Problems first arose on Feb. 4, when workers on the Ensco 87 jackup rig detected a kick, or uncontrolled flow of fluid, in the well. In response, they activated a blowout preventer, which apparently was successful in keeping natural gas from escaping the well.
However later testing revealed that gas had migrated from the bottom of the roughly 8,300-foot well to a shallower sand formation 1,100 feet below the seabed.
After at least one flight over the site Thursday, the federal Bureau of Safety and Environmental Enforcement said it has detected no gas at the seafloor and no sign of pollution at the location.
Apache spokesman John Roper said the company notified federal regulators after the initial kick and regularly as they responded to the incident. “Once we realized this was unconventional, we started having more discussions (with regulators),” he said.
“We evacuated non-essential personnel, we brought in the experts and we notified the government,” Roper added. “The procedures worked; the safety systems are doing their job.”
Former drilling regulator Michael Bromwich said that based on public information, “it appears that both the company and the government have acted properly.”
“Even so, this incident is a sobering reminder that offshore drilling is an inherently risky activity,” said Bromwich, now a consultant in Washington, D.C. “It undermines the often-repeated but erroneous claim that drilling in shallow water has few risks, and reinforces the conclusion that heightened safety and environmental standards should be applied across the board.”
Losses of well control are relatively rare in the Gulf of Mexico; there was just one reported to the Bureau of Safety and Environmental Enforcement in 2012, three in 2011 and four in 2010. Twenty-one such incidents took place from 2007 to the end of 2009.
- One of the 2011 episodes occurred during a plugging and abandonment procedure at a shallow Apache well about 93 miles from shore. When a disturbance was noticed on the water, operations were halted and 42 workers on a liftboat and platform were evacuated to a safe distance.
- In August 2011, a Black Elk Energy well vented gas, prompting workers to activate the blowout preventer at the site. But shearing rams — not pipe-holding rams — had inadvertently been engaged, causing 40 feet of pipe to be cut and drop in the hole.
- And in September 2011, at a Stone Energy Corp. facility operating in 1,100 feet of water, workers noticed a half-mile-long sheen, and liquids coming out of a flare boom. Wells were manually shut in, and later calculations put the amount of fluids spilled at several gallons.
- Regulators have not released information about the 2012 incident.
The safety bureau requires oil and gas companies to report “loss of well control” events, defined as any uncontrolled flow of the formation or other fluid, be it at the surface or underground. Companies also must reported uncontrolled flows resulting from a failure of surface equipment or procedures and flows through diverters.
At the safety bureau’s direction, Apache is moving the Rowan Cecil Provine rig to the site in case it needs to bore a relief well. It was unclear when the Rowan rig would be on site.
The well control specialists at Boots & Coots, a Halliburton company, oversaw drilling of a relief well at BP’s failed Macondo well in 2010.
A relief well — drilled to intersect the existing well at the site — could become necessary, if the well cannot be killed through other means, such as by circulating heavy fluids into the well. A relief well would allow an alternate path for pumping heavy drilling muds and cement at the site.