On Sunday during his visit to the Gulf Coast, President Obama describes the gulf oil leak as “A Massive and Potentially Unprecedented Environmental Disaster”, the scope of the environmental disaster are becoming clearer, as well as the causes.
Halliburton in spotlight in gulf spill probe
“What we do know is that highly pressurized oil is coming out of the wellhead with no control possible at this time,” said Richard Charter, a drilling expert with the Defenders of Wildlife. “For that to happen, at least three redundant fail-safe mechanisms on and below the rig had to either fail to operate or not have been properly installed.”
The oil rig is managed by British Petrolium (BP), the specific problem appears to have arouse from work being done by Halliburton.
After an exploration well is drilled, cement slurry is pumped through a steel pipe or casing and out through a check valve at the bottom of the casing. It then travels up the outside of the pipe, sheathing the part of the pipe surrounded by the oil and gas zone. When the cement hardens, it is supposed to prevent oil or gas from leaking into adjacent zones along the pipe.
As the cement sets, the check valve at the end of the casing prevents any material from flowing back up the pipe. The zone is thus isolated until the company is ready to start production.
The process is tricky. A 2007 study by the U.S. Minerals Management Service found that cementing was the single most-important factor in 18 of 39 well blowouts in the Gulf of Mexico over a 14-year period.
Halliburton has been accused of performing a poor cement job in the case of a major blowout in the Timor Sea off Australia last August. An investigation is underway.
The company had four employees stationed on the rig at the time of the gulf accident, all of whom were rescued by the Coast Guard. It had completed the final cementing of the well and pipe 20 hours before the blowout April 20.
Read the full article at Los Angelas Times.
PBS NewsHour: Gulf Oil Leak: Facts and Figures.
Update from the Gulf: In Louisiana, Local Fishermen Tapped to Help Oil Spill Cleanup Effort.
PBS News Hour – Monday, May 3, 2010
GULF OIL CLEANUP | BP said it will pay to clean up the oil slick still spreading in the Gulf of Mexico. Judy Woodruff gets the latest update on the crisis from correspondent Tom Bearden in Louisiana.
POLITICAL FUTURE OF OFFSHORE DRILLING | Judy Woodruff gets two points of view on the future for offshore drilling in the U.S., from Kert Davies of Greenpeace and Sara Banaszak, an economist with the industry trade group, the American Petroleum Institute.