Chemical Safety Board to investigate Oklahoma rig explosion

The U.S. Chemical Safety Board said it will launch a full investigation into the Oklahoma rig explosion that killed five people this week as Oklahoma authorities suggested that an equipment failure might have contributed to the tragedy.

The Chemical Safety Board, an independent federal agency charged with investigating industrial chemical accidents, typically only gets involved in the largest, deadliest industrial disasters. The board averages about six investigations a year.

The well fire, which swept through a drilling rig owned by the Houston company Patterson-UTI, was the deadliest U.S. accident in the oil and gas industry since the 2010 Deepwater Horizon tragedy in the Gulf of Mexico killed 11 people. Oklahoma regulators said their initial findings suggest that the failure of the blowout preventer — the same type of equipment that failed in the Deepwater Horizon accident — may have led to the explosion at a drilling site near Quinton, Okla., about 100 miles southeast of Tulsa.

A blowout preventer is equipment at the wellhead designed to control and monitor the well. It’s the last line of defense to seal the well and prevent an uncontrollable release of oil or gas.

The initial report from the Oklahoma Corporation Commission, which regulates oil and industry in the state, said an uncontrolled gas release from the well led workers at the drilling site to engage the blowout preventer to shut off the well, but the blind rams — two heavy steel blocks that meet in the middle of the wellbore to seal a well — failed to close.

Commission spokesman Matt Skinner emphasized that the investigation is in early stages and these are only initial findings. A Patterson-UTI spokesman said Thursday that the company has just begun its efforts to determining the cause of the accident and had no further comment.

The well was operated by Red Mountain, a small Oklahoma oil and gas company. Patterson-UTI ran the drilling operation as Red Mountain’s main contractor.

Three of the five killed were Patterson-UTI employees, including one Texan. The victims are Josh Ray, of Fort Worth; Cody Risk, of Wellington, Colo.; and Matt Smith, Parker Waldridge and Roger Cunningham, all of Oklahoma. Ray, Smith and Risk were Patterson-UTI employees.

Patterson-UTI had a spotty safety record in the past decade but, under new leadership, it had improved its safety record in recent years.

“Certainly, for me and the leadership we have today, safety is the top priority,” said Patterson-UTI CEO Andy Hendricks in a Tuesday interview, declining to comment much on the company’s previous safety record. “There have been cases in the past, but I think the record shows — certainly in the last few years — we’ve been one of the safest companies in the industry.”

Patterson-UTI has about 25 drilling rigs active in Oklahoma, second only to Texas, where it has nearly 60 rigs in operation.

Two investigators from the Chemical Safety Board arrived at the site of the accident on Wednesday, the agency said. The board’s last major investigation focused on the Arkema chemical fires near Houston during Hurricane Harvey last year.

The U.S. Occupational Safety and Hazard Administration is also investigating the explosion.

On Tuesday, the Oklahoma Supreme Court struck down part of the state’s workers compensation law, allowing workers and their families to sue energy companies when they’re injured or killed.