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Gulf Oil Spill: Relief bore intersects BP's broken well

September 16, 2010 |  8:55 pm

Federal officials announced Thursday night that an emergency relief well has successfully intersected the bottom of BP's damaged Gulf of Mexico oil well.

"Through a combination of sensors embedded in the drilling equipment and sophisticated instrumentation that is capable of sensing distance to the well casing, BP engineers and the federal science team have concluded that the Development Driller III relief well has intersected the Macondo well," retired Coast Guard Adm. Thad Allen, the federal spill commander, said in a statement.

Crews will next prepare to pump cement into the well's outer ring "and complete the bottom kill of the well," Allen said.

The breach of BP’s well, after months of emergency drilling to more than two miles below the ocean floor, sets up a rapid endgame to a five-month saga that began April 20, when an explosion and ensuing fire aboard the Deepwater Horizon drilling rig killed 11 workers and sent the vessel to the sea floor two days later.

The gush of oil from the blown-out well became the worst offshore oil spill in U.S. history, spewing 205 million gallons until engineers affixed a cap to the well in July.

The disaster closed fisheries in the Gulf of Mexico, sidelining workers and dealing a heavy blow to the seafood industry and to seaside beach towns from Louisiana to Florida. It is blamed for the death of at least 5,939 birds, 584 sea turtles and more than 60 dolphins, although scientists believe the hidden toll is much higher.

The spill also led to a moratorium on deep-water drilling that has been the subject of court battles and political fighting between the Obama administration and largely Republican elected officials in the gulf and elsewhere.

BP’s market value plummeted, and as of Sept. 16, the oil giant had shed 34% of its market capitalization compared with its December 2009 value. BP estimates it has spent more than $6 billion on cleanup and compensation, over and above the $20 billion it has deposited in an escrow fund to compensate for economic damages.

At its height, the cleanup effort involved thousands of vessels and tens of thousands of workers deployed in four states. About 966 miles of shoreline were soiled by the mixture of Louisiana light crude and chemicals used to disperse it.

Of the 4.9 million barrels of oil that gushed from the well, one-quarter was burned, skimmed or piped to tanker ships, according to an August report released by the National Oceanic and Atmospheric Administration.

A second quarter has evaporated or dissolved. A third quarter, which the government calls “residual” oil, made its way into the ocean as a light sheen on the water or as tar balls.

The remaining quarter is believed to be deep below the surface of the gulf in vast clouds of atomized droplets that could alter links in the chain of sea life that scientists are only beginning to understand.

This “dispersed” oil was broken into droplets by the 1.8 million gallons of the chemical dispersant Corexit, which was sprayed on the ocean's surface and deep under the sea.

A massive federal effort to map and study these plumes, some of which are 1,200 to more than 4,000 feet below the surface, is underway.

-- Richard Fausset, in Atlanta and Bettina Boxall in Los Angeles