This is an update from the joint hearings by the Coast Guard and the Bureau of Ocean Energy Management, Regulation and Enforcement investigating the causes of the Deepwater Horizon oil rig explosion on April 20.
In a suprise announcement to conclude Tuesday's Marine Board investigative hearings in Kenner, four Transocean employees who were scheduled to testify Wednesday decided not to show up.
David Adler, an attorney representing two of the scheduled witnesses, said he is trying to review pertinent documents that the Coast Guard has not released to him. The other two witnesses are represented by attorney Steve London, who suddenly faces a conflict because a client of his was named a "party of interest" by investigators earlier Tuesday.
The scheduled witnesses were supposed to provide testimony about modifications to the rig's blowout preventer. They are: subsea supervisors Ray Odenwald, Jim McWhorter and Mark Hay and subsea superintendent Billy Stringfellow.
Adler represents Hay and Stringfellow, while London represents Odenwald and McWhorter. London also represents the rig's chief engineer Stephen Bertone, who testified Monday and was added to the list of parties of interest by the panel.
The panel was caught off-guard by the cancellations Tuesday and was forced to cancel Wednesday's hearing. The hearings will continue Thursday, Coast Guard Capt. Hung Nguyen said.
Three other scheduled witnesses have previously refused to show up for one reason or another. One, BP company man Robert Kaluza, invoked his Fifth Amendment right not to incriminate himself. His fellow company man, Donald Vidrine, has twice called in sick. And toolpusher Wyman Wheeler, a Transocean employee, didn't show up Monday because of an illness.
In addition, Transocean executive Daun Winslow had been scheduled to testify Wednesday and had to reschedule to August hearings in Houston.
Coast Guard spokesman Chief Mike O'Berry said Wednesday's four witnesses had all agreed to testify voluntarily, then withdrew. He said subpoenas compelling them to appear had not been issued yet.
BP ordered a lockdown sleeve, a device used to hold tubes in place inside the well, but never got to install it because, contrary to traditional practice, the company decided to wait to place it until protective drilling mud was removed.
Testifying before a Marine Board investigative panel, Ross Skidmore, a veteran subsea well supervisor in charge of installing the lockdown sleeve, said that in his 33 years in the business, he had always seen the device installed in the mud that sits in the well and guards against explosive kicks of gas.
"This was the first time I'd seen it (planned) after spacing out,"or replacing the heavy mud with lighter seawater, Skidmore said. He said he questioned the plan onboard, but he was new to the rig and deferred to others.
"I asked why couldn't we go ahead and do this in mud," he said. "I was told it wasn't going to happen. We were going to go through in the sequence we were given."
The testimony was yet another indicator that in spite of dangerous readings and confusing test results, BP and the rig crew didn't pick the safest procedures in the moments before the disaster.
Add to the lockdown sleeve issue BP's decisions to forego a test of gas presence in the well, to skip another test that would have measured the integrity of cement barriers and to ignore a warning from cementer Halliburton two days before the disaster that its well design brought a "SEVERE gas flow problem."
Skidmore said the rig workers saw the finish line on that well and may have relaxed.
"Everyone went to the mindset this job is through," he said. "When you run the last string of casing and there's a test done on it, you say, 'This job, we're at the end of it, we're going to be OK.' I'm not talking from supervisor's view, but from the working man's."
A Marine Board panel investigating the cause of the Deepwater Horizon explosion has released a list of "anomalies" it believes were experienced on the rig in the 36 hours leading up to the April 20 accident.
At noon on April 20, about 10 hours before the rig was engulfed in natural gas-fueled flames, 15 barrels of the drilling mud that guards against gas kicking upward bled back to the rig as pressure on the well below was released. The investigators say that was higher than the 5 barrels that typically come back during such a pressure release.
In the afternoon, the rig crew was pumping drilling mud out tosupply boat at the same time as seawater was being pumped into the well, a time-saving measure the investigators said made it hard to track fluid in the well hole -- fluid that is measured to determine if the well is safe for closing in.
Just before 5 p.m., investigators suspect the annular valve on the blowout preventer was leaking. A few minutes later when the drilling team ran the first of two key tests called a "negative pressure test," they measured 1,250 pounds per square inch of pressure on the drill pipe.
That was apparently a high level of pressure, but BP interpreted the negative test as a success, indicating it would be safe to remove the protective drilling mud and place a final cement plug in the hole.
But the investigators found that the pressure on the pipe was a cause of concern for some onboard the rig:
"Some employees recalled a disagreement between Transocean (the rig's owner) and BP on the rig floor about the negative test and pressure on the work string," the investigators' report states.
During the negative test, another 15 barrels of drilling mudescaped, and the investigators' report says the well kept flowing,which could have been an indication that the kill line on the blowoutpreventer that should have closed in the well was "plugging."
At 7:10 p.m., about two hours and 40 minutes before the explosions, the two top BP officials in charge, company men Robert Kaluza and Don Vidrine, were involved in a discussion about drill pipe "pressure anomaly," the report said.
In the final two hours, electronic data indicated the well, whichwas supposed to be static in preparation for temporary abandonment, kept flowing. Finally, about 20 minutes before the explosions, pumping of mud had stopped, but the investigators said there was a possible report from the rig's mud pits that mud was coming back from the well anyway.
David Hammer can be reached at firstname.lastname@example.org