In light of Coast Guard Adm. Thad Allen’s announcement, Sunday, that the Macondo 252 well has finally been sealed for good, we’re dedicating an entire hour to the Deepwater Horizon oil spill. It’s been a long and tortuous saga, replete with conflicting information, so here’s a quick re-cap of events.
1998: Hyundai Heavy Industries commences construction on the Deepwater Horizon in Ulsan, South Korea.
February 23, 2003: After being transported halfway around the world, the rig is delivered to the Gulf of Mexico where it will drill for several years at multiple oil fields.
April 20, 2010: A methane bubble comes up from the well and explodes, killing 11 and injuring 17. The subsequent fire will burn for two days and ultimately sink the platform. The blow-out preventer, a device on the ocean floor engineered to stop the flow of oil in case of emergency, fails to engage, and crude oil gushes from the wellhead some 5,000 feet below the water’s surface.
April 25: Robots deployed to trigger the blow-out preventer manually are unsuccessful. Initial estimates derived from underwater video footage put the flow rate at 1,000 barrels of oil per day, but this figure will increase five-fold over the course of the following week.
April 27: The slick of oil on the surface of the Gulf of Mexico stretches for 100 miles; the Coast Guard sets fire to portions of slick to reduce the quantity of oil in the water. That same day, BP reports a rise in profits as global oil prices increase.
April 30: Ten days after the initial explosion, the Obama administration issues a moratorium on deepwater drilling. The decision sparks controversy in Gulf communities dependent on oil drilling jobs. The 5th U.S. Circuit Court of Appeals will effectively overturn the ban on July 9.
May 8: BP lowers a four story metal dome over the gushing well, but the formation of ice-like gas hydrate crystals threatens to float the dome away; BP abandons the dome. Tar balls begin washing ashore in Alabama.
May 20: BP announces that a tube lowered down to the leaking wellhead is drawing up 5,000 barrels of oil per day. Since this was originally thought to be the leak’s total daily output, previous flow estimates are revised yet again to 20,000 bpd.
May 26: BP attempts a technique known as a ‘top kill,’ during which thousands of barrels of sludge are pumped into the well in order to stop the flow of oil. This, too, will ultimately fail.
June 12: Scientists double the official flow-rate estimate to 40,000 bpd after congress pressures BP to release new video footage of the leak.
July 12: With the original drilling moratorium stymied by the Fifth Circuit, Secretary of the Interior Ken Salazar issues a second, slightly changed moratorium, set to expire on November 30.
July 15: A smaller containment cap stops the leak completely for the first time.
August 4: BP announces the success of a ‘static kill’: an effort to seal the leak using a mixture of cement and heavy drilling mud.
September 16: A relief bore drilled to a depth of 2.5 miles below the ocean’s surface reaches the Macondo 252 well. A cement plug is pumped in the next day.
September 19: A final pressure test determines that the leak is permanently closed, and Adm. Thad Allen releases a statement saying the well is “effectively dead.”