Paula Dittrick
OGJ Senior Staff Writer
HOUSTON, Aug. 25 -- BP PLC has flushed out hydrates that it found in Transocean Ltd.’s Deepwater Horizon semisubmersible blowout preventer and a capping stack on the blown-out Macondo well in the Gulf of Mexico, a government spokesman said.
BP hoped to replace the Deepwater Horizon BOP on Aug. 26, but that timetable now has been pushed back by at least 24-36 hr. Oil spill response workers believe the system now is free of hydrates.
National Incident Commander and retired US Coast Guard Adm. Thad Allen said hydrates prevented BP from opening one set of rams that it previously closed during pressure tests in the lower marine riser package. The LMRP has another five-ram package, and it’s unclear yet whether those lower rams can be activated, he said.
BP worked Aug. 25 to remove two pieces of drill pipe and to evaluate the condition of a third drill pipe. Allen said one pipe that he previously estimated at 1 ft is actually 18 in. and a second pipe that he had estimated at being 40 ft is actually about 13 ft. The length and condition of the third pipe remains to be determined, he said.
He said the third pipe, previously estimated at 3,000-3,500 ft, might have been cut by a ram in which case BP expects to be able to remove that pipe first and then replace the BOP before completing a relief well.
Another potential scenario is that the pipe is not cut and extends well below the BOP. This could mean that BP has to remove the pipe while it’s still attached to the BOP, Allen said, adding that BP is formulating plans to do that if necessary.
There also is a chance that the pipe might be in contact with cement that was pumped into the well during the earlier “static kill” process.
“We’re not ruling out the possibility that some cement could have adhered to it,” Allen said. Consequently, BP engineers and federal scientists are studying “how much pull should we put on the blowout preventer.”
BP monitoring water
On Aug. 25, BP planned to deploy two satellite-controlled, unmanned vehicles in the gulf as part of its long-term monitoring and research program.
The vehicles, known as Wave Gliders and developed by Liquid Robotics in Silicon Valley, Calif., receive propulsion power from wave action and use solar power for their electronics.
“These vehicles will provide us a steady stream of data about water quality and should significantly increase the available data for ongoing research activity,” said Mike Utsler, chief operating office of BP’s Gulf Coast restoration organization. “We will initially deploy the Wave Gliders between the Macondo well and the shoreline.”
Sensors will monitor water for any emulsified, dissolved, and dispersed oil as well as monitoring for phytoplankton (chlorophyll); and colored, dissolved oxygen matter (CDOM).
Roger Hine, Liquid Robotics president and chief executive officer, said nine optical sensors will be calibrated to monitor water quality, including trace amounts of dispersed oil. The sensors later are expected to be calibrated to include acoustic monitoring of marine mammal activity.
A second pair of Wave Glider vehicles was scheduled to be deployed in September. Data collected by the vehicles will be relayed via satellite and posted on a public web site, BP said.
Contact Paula Dittrick at [email protected].
US Government Accountability Office.
