2010 – The Deepwater Horizon drilling rig explodes in the Gulf of Mexico, killing eleven workers and beginning an oil spill that lasted six months.
Deepwater Horizon was an ultra-deepwater, dynamically positioned, semi-submersible offshore drilling rig owned by Transocean and operated by the BP company. On 20 April 2010, while drilling in the Gulf of Mexico at the Macondo Prospect, a blowout caused an explosion on the rig that killed 11 crewmen and ignited a fireball visible from 40 miles away. The fire was inextinguishable and, two days later, on 22 April, the
Horizon collapsed, leaving the well gushing at the seabed and becoming the largest marine oil spill in history. Built in 2001 in South Korea by Hyundai Heavy Industries, the rig was commissioned by R&B Falcon (a later asset of Transocean), registered in Majuro, and under lease to BP from 2001 until September 2013. In September 2009, the rig drilled the deepest oil well in history at a vertical depth of 35,050 feet and measured depth of 35,055 feet in the Tiber Oil Field at Keathley Canyon block 102, approximately 250 miles southeast of Houston, in 4,132 feet of water. At 7:45 p.m. CDT on 20 April 2010, during the final phases of drilling the exploratory well off the gulf of Mexico, a geyser of seawater erupted from the marine riser onto the rig, shooting 230 feet into the air. This was followed soon by the eruption of a slushy combination of drilling mud, methane gas, and water. The gas component of the slushy material quickly transitioned into a fully gaseous state and then ignited into a series of explosions and then a firestorm. An attempt was made to activate the blowout preventer, but it failed. The final defense to prevent an oil spill, a device known as a blind shear ram, was activated but failed to plug the well. Ten workers were presumed killed by the initial explosion and an eleventh worker, a crane operator, also died in the subsequent fire. The resultant oil spill continued until 15 July when it was closed by a cap. Relief wells were used to permanently seal the well, which was declared "effectively dead" on 19 September 2010.
