Federal drilling regulators on Monday launched a formal investigation into the blowout of a gas well in the Gulf of Mexico last week that forced the evacuation of 44 workers and ignited a fire that raged for nearly two days.
The Bureau of Safety and Environmental Enforcement began the probe even as workers prepared to drill a relief well at the site so they could plug the original well with cement. Although sand and debris clogged the well Thursday, halting the flow of natural gas and starving the fire of fuel, it could take at least two weeks to plug the hole permanently.
Safety bureau officials said the agency will work with the Coast Guard in examining what caused gas to escape from the well on the morning of July 23 and ignite late that evening. The fire caused the derrick to collapse on the Hercules 265 jack-up rig that had been drilling the well for Houston-based Walter Oil and Gas Corp. Hercules Offshore, the rig owner, also is headquartered in Houston.
Environment: Scientists collect water near site of blown well
A safety bureau engineer based on the Gulf Coast and other agency specialists will lead the investigation.
It’s still unclear what ignited explosive gas on the Hercules rig, but Coast Guard officials speculated last week that friction heat from sand and debris flowing through the blowout preventer on the rig might have triggered the the flames. The blowout preventer is a system of valves, shears and rams meant to cut through drill pipe and seal off well bores in emergencies.
The investigators aim to determine the cause of the blowout and fire and to develop recommendations to prevent similar incidents, the agency said.
A similar probe is continuing into a fire at a Black Elk Energy oil production platform last November that killed three workers. In February, the safety bureau completed a final report on a fatal crane accident two years ago at an offshore production platform owned by Houston-based Energy Resource Technology.
The Coast Guard, Walter Oil and the safety bureau are coordinating the response to the latest incident. They initially set up the unified command center in Houma, La., but now are collaborating remotely as the danger of injuries and significant pollution appears to have past.
Light sheens had been detected at the site of the gas well, about 55 miles from the Louisiana coast. But they have dissipated quickly and safety bureau officials said they weren’t sure if sheens were present Monday.
The natural gas well poses less danger of environmental damage than an oil well blowout like the BP spill in 2010. Booms, skimmers and other specialized equipment can’t always sop up all of an oil spill.
Natural gas naturally evaporates over time, though not without environmental effects as its main component is the greenhouse gas methane. Although methane does not remain in the atmosphere as long as other greenhouse gases, it is 21 times more potent than carbon dioxide in warming the atmosphere.
Safety bureau engineers on Saturday approved Walter’s permit to drill a relief well using the Rowan EXL-3 rig. Meanwhile, workers installed natural gas detectors and high-capacity water hoses on the damaged Hercules rig.