A natural gas well blowout and fire on Jan. 22 killed five workers at a Pryor Trust gas well located in Pittsburg County, Okla. The incident occurred while workers were attempting to remove a drilling pipe and replace a worn drill bit.
Pressure from adding drilling mud and weighted liquids were insufficient to offset and block explosive natural gas from exiting the 4,000 m well, the U.S. Chemical Safety & Hazard Investigation Board (CSB) said on Aug. 16 in a factual update of its ongoing investigation.
CSB notes that workers were unable to fully activate a blowout preventer and block the gas, oil, and mud as it exited the well. The accident occurred one week after drilling began and the fire burned for eight hours until crews were able to activate the preventer. The well was operated by Red Mountain Operating and the drilling was done by Patterson-UTI Drilling Company.
CSB released a video animation of the accident, but a report is likely to be a year away. CSB is increasing factual updates it releases, notes board spokesperson Hillary Cohen. “We want to update stakeholders, the public, and industry, throughout the course of the investigation,” she says.