Like a hurricane menacing the Gulf Coast, the full damage from the destroyed deepwater oil well in British Petroleum’s Mancando field in the Gulf of Mexico won’t be known for many days. Nor will the cost, now estimated to be in the billions, as offshore crews work tirelessly to keep crude from coming onshore and landside volunteers prepare to begin the massive environmental cleanup. How much is at stake could be read more easily in faces than in financial calculations. “I look in the eyes of fisherman and people making their living on the coast, and you just see fear,” says Bob Thomas, director of the Center for Environmental Communications at Loyola University in New Orleans. “So far we haven’t realized the real damage because it hasn’t come into our marshes.”
BP is spending $6 million a day on cleanup costs and, on May 3, said it was giving coastal states $25 million to begin cleanup efforts. Experts say the cleanup could cost BP $4.5 billion to $6 billion.
The oil leak, coming from 40 miles off Louisiana’s coast, began after an April 20 explosion aboard Transocean’s Deepwater Horizon semisubmersible drilling unit. The explosion occurred when oil and gas from the well, 18,000 ft below the mudline under 5,000 ft of water, reached the surface of the rig and ignited. There were 126 crew members aboard the rig; 11 are still missing and presumed dead, and 17 others were injured. Two days later, a second explosion sank the rig. Although Geneva, Switzerland-based Transocean was operating the rig at the time of the accident, BP is held liable by the U.S. government because it is leasing the oil field.
The leak that is believed to have caused the explosion continues to gush into the Gulf of Mexico, with an estimated 210,000 gal of oil a day coming out at the wellhead and at two spots in a riser pipe that crumpled when the Deepwater collapsed. Doug Suttles, chief operating officer for exploration and production for London-based BP, said on April 30 that estimates of the oil leak were “highly imprecise,” because there is no way to measure the oil coming from the well.
Preliminary reports indicate the accident occurred as Halliburton, based in Houston and Dubai, completed concrete placement around the well bore. The oilfield services contractor confirmed it had completed the final production casing about 20 hours before the incident. The company says it had completed pressure tests to demonstrate the integrity of the casing around the well bore.
Bud Danenberger, former offshore regulatory division chief of the U.S. Minerals Management Service, believes there was some “fundamental problem with the [blowout preventer, or BOP] stack” or a mix of human error and a faulty BOP.
A May 3 report by Robert MacKenzie, an oil-industry market analyst with an engineering background, theorizes that “incomplete isolation by the cement allowed a buildup of annular pressure, which contributed to a casing collapse during a negative pressure test, after which the BOP was unable to seal the well due to an obstruction too thick for the BOP to crush/shear, such as a tool joint of drill pipe.”
Change of Direction. The accident and its aftermath immediately shifted the debate on offshore drilling. The Obama administration said on April 29 the spill could affect its decision to open up new areas to drilling, and on May 3 California Gov. Arnold Schwarzenegger (R) retracted his support for drilling off Santa Barbara.
As crews and onshore volunteers—from Pensacola, Fla., to Port Fourchon, La.—prepared to clean up the oil once it reached the coast, BP worked on multiple fronts to stem the flow. “The first thing is to stop this thing at the source,” says Coast Guard Adm. Thad Allen, tapped on May 1 by the Obama administration to coordinate the joint-task-force response to the spill. “To continue to fight this thing on the surface and shore is not the way to do it.” The JTF deployed nine remotely operated vehicles (ROV) to the seafloor to assist in stopping the oil flow.
For more than a week after the explosion, BP’s efforts focused on activating a blowout preventer, manufactured by Houston-based Cameron International, that was placed on top of the well during drilling. The 450-ton, 40-ft-high, 16-ft-wide BOP has hydraulically operated rams that, when activated, act as a shut-off valve for the 5- to 7-inch riser pipe. One of the rams is a shear, which cuts the pipe to stop the flow of oil and gas. The safety devices, which are rated to at least 15,000 psi, are designed to activate when turned on from a rig above or when power is lost, says Danenberger. The BOP was tested 10 days before the explosion. On May 3, Suttles said that tests performed by the ROVs indicate the BOP was at least partially activated; BP believes oil is leaking from its seals.
Focusing on other options, BP is now considering removing the faulty BOP and installing another. The company also said on May 3 that it expects to deploy a containment dome over one of the leaks within a week. The 98-ton box, being built by Houston-based Wild Well Control Inc., Port Fourchon, La., would capture the oil floating to the surface and pipe it to a Transocean drill ship that can hold 125,000 barrels of oil. That method has been used in shallower waters.
“The real problem is the engineering associated with that and how to mechanically accomplish that 5,000 ft down,” Allen says. ROV operators are currently pursuing another option: crimping and cutting the leaking riser pipe. That solution would lessen, but not stop, the flow.
Suttles, Allen and others say the most likely way to stop the oil is by drilling a relief well—a 90-day process—and plugging the hole in the existing well.
Above the oily Gulf waters, planes dropped more than 156,000 gal of dispersant into the slick. The proprietary chemical mix acts like soap and breaks down the oil on and below the surface into less harmful molecules. The dispersants have toxic qualities, says Thomas, “but we’ve got to get rid of this oil.”
The JTF deployed a 200-vessel remediation fleet, including surface-skimmer boats. As of May 4, they had retrieved more than 1 million gal of oil and water.The week of May 3, favorable winds were keeping most of the oil from reaching land; the estimated size of the oil sheet shrank, to 2,000 sq miles from 3,400 sq miles. The Mississippi’s flow is keeping the spill east of the river mouth, and some scientists worry that the farther south and east the oil moves, the more likely the spill could hit the Gulf Stream and make its way up the East Coast.