U.S. finds faulty bolts on some offshore rig blowout preventers

Wed Feb 6, 2013 6:07pm EST

Feb 6 (Reuters) - U.S. regulators have told offshore rig contractors in the Gulf of Mexico to inspect blowout preventers (BOPs) after a faulty bolt was deemed responsible for a leak of drilling fluid late last month.

The U.S. Bureau of Safety and Environmental Enforcement said on Wednesday that General Electric Co issued a safety notice to customers on Jan. 29 regarding bolts used in its H-4 connector, which connects the BOP to the wellhead.

"Less than a third of the rigs operating in the Gulf were affected by GE's safety notice," the BSEE said. "The inspections and verifications are being done on a rolling basis."

Angie Sedita, an analyst at UBS, said BOPs made by National Oilwell Varco Inc would also be affected, although Cameron International Corp BOPs would not. She calculated a total of 20 GE and 12 NOV BOPs in the Gulf, and expected that 32 rigs off the coast of Brazil would need to be inspected as well.

"The downtime would likely be at the expense of the contract drilling company, but there would still be a discussion between the driller and customer," Sedita said in a research note.

She estimated an impact of up to 10 percent of first-quarter profits for the major rig operators Transocean Ltd, Ensco Plc, Diamond Offshore Drilling Inc and Noble Corp, assuming five days downtime for each rig, but far more in the worst case that could take as long as 14 days.

A Transocean official confirmed on Tuesday there was a plan to replace the bolts as necessary, but added: "At this time, we do not expect this issue to have a significant impact on our business."