BP says 'top kill' fails to stop flow from leaking gulf well

BP PLC said May 29 that the “top kill” operation failed to stop the flow of oil and gas from the runaway Macondo deepwater well in the Gulf of Mexico off Louisiana, and oil spill response crews next will work to install a new collection system on top of the failed blowout preventer (BOP).

Paula Dittrick
Senior Staff Writer

HOUSTON, May 29
– BP PLC said May 29 that the “top kill” operation failed to stop the flow of oil and gas from the runaway Macondo deepwater well in the Gulf of Mexico off Louisiana, and oil spill response crews next will work to install a new collection system on top of the failed blowout preventer (BOP).

BP Group Chief Executive Tony Hayward said, “We worked the top kill procedures hard for 3 days. We pumped more than 30,000 barrels of mud at high pressures through the system. We fired 16 different bridging material shots.”

He said BP, industry experts, scientists, and government officials studied the data throughout the top kill process. The next step is deployment of the Lower Marine Riser Package (LMRP) Cap Containment System, which already is sitting on the seabed.

“Together with our counterparts in government, we made the decision that the best way to minimize the flow of oil into the gulf is to set aside top kill and move immediately to place a containment cap over the leak,” Hayward said.

"I am disappointed that this operation did not work,” Hayward said. “The team executed the operation perfectly, and the technology worked without a single hitch. We remain committed to doing everything we can to make this situation right."

Despite successfully pumping a total of over 30,000 bbl of heavy mud, in three attempts at rates up to 80 bbl/min, and deploying a wide range of different bridging materials into the BOP, the operation did not overcome the flow from the well, BP said. Bridging materials and the junk shot were used as expected (OGJ, May 24, 2010, p. 22).

BP and partners hired Transocean Ltd.’s semisubmersible, Deepwater Horizon, to drill the Macondo well on Mississippi Canyon Block 252. The Deepwater Horizon exploded Apr. 20, leaving 11 crew members dead. On Apr. 22, the rig sank.

New containment system
Doug Suttles, chief operating officer of BP Exploration & Production, said the top kill pumping started at 1 p.m. CDT on May 26. The operation involved repeatedly pumping awhile and then stopping and monitoring the well. The decision to give up on the top kill effort was made about 4 p.m. on May 29.

“The next thing to do is to capture as much of the flow as we can,” Suttles said, adding the LMRP cap is expected to collect a majority of the leaking oil and gas. “It’s another version of what we used to call top hat” (OGJ, May 17, 2010, p. 23). The collected oil and gas will go to a drillship on the surface.

The LMRP cap installation involves cutting and then removing the damaged riser from the top of the failed BOP to leave a cleanly-cut pipe. The cap is designed to be connected to a riser from Transocean’s Discoverer Enterprise drillship and placed over the LMRP with the intention of the cap capturing most of the oil and gas flowing from the well.

BP said the LMRP cap “has not been previously carried out in 5,000 ft of water, and the successful deployment of the containment system cannot be assured.”

The first relief well has reached 12,090 ft of its 18,000 ft TD. Drilling of the second relief well is temporarily suspended and is expected to recommence shortly. It’s at 8,576 ft.

“This scares everybody, the fact that we can’t stop this flow,” Suttles said. “We are going to keep after it until we get it fully contained, fully stopped, and until we get this relief well done.”

Contact Paula Dittrick at paulad@ogjoinline.com.

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