Nigeria - New Revelations About Chevron Rig Explosion That Killed Two

Chevron Corp. left workers pleading to be evacuated from a gas exploration platform off Nigeria which kept drilling as smoke poured from a borehole until an explosion that killed two people as the rig became engulfed in flames, according to accounts from four of the platform's workers.

Chevron, the second largest U.S. oil major, said it did not receive requests to evacuate the KS Endeavour rig and that staff on board had the right to call a halt to work if they believed conditions were unsafe.

"There were no evacuation requests received before the KS Endeavour incident occurred," the U.S. energy company said in an emailed response to questions from Reuters.

Testimony from some of the 154 workers who were present alleges that, instead of addressing fears that equipment failures and smoke presaged disaster, Chevron flew extra staff to the platform just before the January 16, 2012, blowout.

Chevron says a nationwide Nigerian strike that included staff at airports had disrupted its normal crew changes but that at no time were approved safe manning levels exceeded.

The fire that followed the blast burned on the rig for 46 days until March 2. Chevron drilled a relief well to stem the gas leak, sealing it on June 18. It said in an email to Reuters on July 2 that an investigation with the Nigerian authorities had concluded that an entry of high pressure gas in the wellbore had caused the failure of equipment and fire.

The two who died in the explosion were the installation manager for the rig, Bruno Marce, a French national, and Indian driller Albert Devadas. They worked for KS Drilling, a subsidiary of Singapore-based KS Energy, a sub-contractor employed by Field Offshore Design Engineering (FODE) Ltd to drill a gas exploration well for Chevron off Nigeria.

Transcripts of accounts from three workers were given to Reuters by the offshore oil branch of Britain's Rail, Maritime and Transport (RMT) trade union which said the documents were genuine but withheld the names of the witnesses to protect their employment prospects. Those accounts were backed by subsequent interviews in Nigeria with a worker who was also on the rig.

FODE declined comment, citing confidentiality clauses in its contract with KS Drilling preventing it making public any information about work for Chevron.

The accounts convey rising panic from some of those on the platform, who fearing a blowout, checked each morning the volume of smoke billowing from the drilling borehole.

"Chevron knew for over a week that the well was unstable yet they refused to evacuate us," said one of the rig workers who gave his account to the RMT union.

A Nigerian worker who was aboard the rig at the time of the blast said many wanted to be evacuated.

Speaking at a hotel in Yenagoa, the oil capital of the Niger Delta's oil-rich Bayelsa state, Omietimi Nana, 28, a maintenance worker for FODE said: "We were told we may be evacuated, it was mentioned but it didn't happen. I don't know who made the decision not to evacuate but certainly many people wanted to be evacuated because of the situation," he said.

The most senior witness to give testimony to the RMT, a Frenchman, said a series of pump failures throughout the drilling operation led to a massive build-up of pressure that triggered the blowout.

The Frenchman said rig engineers held a site meeting and advised Chevron to evacuate staff while well pressure control measures were applied.

"That advice was not heeded and additional personnel were even brought onboard to get ahead of what was believed to be impending strike action," the Frenchman, who was at that meeting, said.

Nana added: "About three days before the accident, the drilling company workers told us they wanted to stop drilling because of the gas pressure but they spoke with Chevron who told them to carry on."

The French witness said an earlier failed attempt in late December to drill an exploration well near the same was abandoned after the discovery of a gas leak.

He said that "in an attempt to learn from experience" Chevron began drilling a second well "despite repeated failure of the pumps" and often having to stop drilling in order to service the top-drive, the device on the rig that provides rotational force.

Chevron acknowledged that the first exploration well was abandoned but denied it was because of a gas leak.