washingtonpost.com
BP ready to go for 'top kill' to try to plug oil well

By Joel Achenbach and Steven Mufson
Wednesday, May 26, 2010; A01

The most critical moment in the oil spill crisis in the Gulf of Mexico is at hand, as BP engineers armed with 50,000 barrels of dense mud and a fleet of robotic submarines are poised to attempt a "top kill" maneuver to plug the gushing well a mile below the surface.

It's far from a sure bet.

"It has been done successfully in the past, but it hasn't been done at this depth," Kent Wells, the oil company's senior vice president of exploration and production, told reporters in a conference call Tuesday.

This will be the first stab at shutting down the well since the April 20 blowout and fire that killed 11 workers on the drilling rig Deepwater Horizon. Efforts to capture the spewing oil have had limited success. The expanding slick has ridden a steady sea breeze onto 70 miles of Louisiana's shoreline and into shellfish-rich estuaries. The sight of oil-soaked brown pelicans is now common. Sticky rust-brown oil slathers the grass in the marshlands. Federal officials closed more fishing grounds Tuesday, bringing the total to more than 54,000 square miles, nearly a quarter of the federal waters in the gulf.

Oil company executives will be grilled in federal hearings resuming Wednesday in a hotel in suburban New Orleans. Later this week, Interior Secretary Ken Salazar is set to deliver a safety review of offshore drilling to President Obama. And then Obama will fly to the gulf on Friday for his second visit to the region since the crisis began. "Like everybody, he's frustrated," Carol Browner, assistant to the president for energy and climate change, told CNN.

The developments on shore may be overshadowed by what happens in the hours and days ahead in the deep water, where the only light comes from the lamps of the robotic submarines. BP's top-kill plan has been devised over more than a month by what BP calls a dream team of engineers from the oil industry and from such government agencies as the Energy Department, the Minerals Management Service and the U.S. Geological Survey. BP has also logged 17,000 suggestions from outsiders, Wells said.

Huge ships and drilling rigs now crowd the surface 5,000 feet above the blown-out well. Two rigs are drilling relief wells but are not expected to complete their work until August. Parked in the middle of everything is the command vessel for the top-kill operation, the 312-foot Helix Q4000. Close by will be the 381-foot HOS Centerline, one of the largest supply ships in the world, capable of pumping 50 barrels of mud a minute. Two other backup ships carrying mud will be nearby.

All the work at depth is performed by the remotely operated vehicles (ROVs), numbering 12 by latest count, and operated from the surface ships while BP engineers monitor the process from Houston. The ROVs have tinkered with the five-story blowout preventer that sits atop the wellhead. They fixed a leaking hydraulic line, for example, using an ordinary wrench pinched by a robotic arm. They also removed the "yellow pod," the brain of the blowout preventer, and engineers repaired it at the surface before replacing it at depth.

On Tuesday, BP engineers began diagnostic tests on the blowout preventer. This is a critical phase in which the company will learn how much pressure must be overcome when the drilling mud is injected into the well. It could also lead them to abort the maneuver.

"We've got a crack team of experts that are going to pore over the diagnostic data," Wells said. "There is a remote possibility that we would get some information that it wouldn't work."

If all goes as planned, a 30,000-horsepower engine aboard the HOS Centerline will pump mud at 40 to 50 barrels a minute to the Q4000 command vessel, then down a newly installed pipe to the gulf bottom, and then through flexible hoses into multiple portals in the blowout preventer.

What happens next would be all-important. The mud would have to go somewhere. The hope is that so much of it would be forced into the preventer that, even as some of it surged up the riser pipe and into the water along with oil and gas, much of it would go to the bottom of the well. The well would lose all pressure and would become static. Later, BP would inject cement down the wellbore to permanently seal the well.

"We know we'll lose some [mud] out the top, but can we pump fast enough to ultimately kill the well?" Wells said. He said the goal is to "outrun the well."

The danger is that the top kill could worsen the situation. The powerful injection of mud might destabilize the blowout preventer, or punch a bigger hole in the sharp kink in the riser just a few feet above the blowout preventer. If the mud doesn't beat back the spill, that could mean a mess of mud mixed with a larger flow of oil and gas.

Greg McCormack, director of the Petroleum Extension Service at the University of Texas at Austin, said he's cautiously optimistic that the top kill will work, saying: "There's always a trade-off between making it better and making it worse. This probably has the least amount of risk of making it worse."

After a protest from Rep. Edward J. Markey (D-Mass.) and discussions with Coast Guard Adm. Thad W. Allen, BP said Tuesday that it will continue to provide live video feed from the sea floor during the top-kill attempt.

The exact timing and pace of the maneuver have not been set, but Wells said the mud injection will begin no sooner than Wednesday. He cautioned that it could take two days to seal the well.

He also gave details for the first time of another backup plan. The top of the blowout preventer would be severed using the robotic submarines. That would temporarily increase the flow of oil into the gulf by 5 to 15 percent, Wells estimated. Then a specially configured containment dome would be lowered onto the blowout preventer. Ideally it would capture much more of the oil than has been contained so far with a small pipe in the end of the leaking riser, he said. That insertion tool has captured an average of 2,000 barrels a day, Wells said, but the well is leaking many times that amount.

The new containment dome could be lowered within a few days if the top kill fails, he said.

Staff writer Juliet Eilperin in Houma, La., contributed to this report.

Post a Comment


Comments that include profanity or personal attacks or other inappropriate comments or material will be removed from the site. Additionally, entries that are unsigned or contain "signatures" by someone other than the actual author will be removed. Finally, we will take steps to block users who violate any of our posting standards, terms of use or privacy policies or any other policies governing this site. Please review the full rules governing commentaries and discussions. You are fully responsible for the content that you post.

© 2010 The Washington Post Company