CSB’s Ongoing Investigation into Fatal Gas Well Explosion in OK

The US Chemical Safety Board is in the early stages of its investigation into the fatal gas well explosion on January 22, near Quinton, Oklahoma, that killed five drilling rig workers.

Red Mountain Operating (RMO) is the leaseholder and operator of the well involved in the incident – referred to as the Pryor Trust 0718 1H-9 well.

In drilling, the operator is responsible for the well’s design and the drilling program, which should account for well-specific conditions that could increase the risk or complexity of the drilling contractor’s various drilling and well control operations.

The drilling contractor, in this case, Patterson-UTI Drilling Company, LLC (Patterson-UTI), brings the infrastructure (drilling rig) and supplies the workforce (rig crew) which operates the drilling rig. Consequently, the drilling contractor also has more direct control over the primary operations (drilling) and emergency response (well control).

Another well had recently been drilled by Patterson-UTI on this pad without incident. Drilling of 1H-9 began on January 11, 2018, and currently, the CSB is unaware of any deviations from the original well plan. At the time of the incident, the rig crew had recently pulled the drill pipe and associated drilling tools out of the well in preparation to change out the drill bit.

Both RMO and Patterson-UTI have cooperated with the CSB’s investigation and promptly provided the well plan, daily drilling reports, and electronic rig data.

The CSB is currently reviewing that information and plans to interview eyewitnesses and others present at the well site beginning as early as next week.

Investigators will return to the site to continue their field work as key pieces of equipment are ready to be collected.