National Geographic : 2010 Oct
FIXED 1938 Up to 1,754 VK821 TENSION-LEG 1989 Up to 5,000 Ram/Powell SEMISUBMERSIBLE 1963 Unlimited Deepwater Horizon FPS* Early 2000s Unlimited Na Kika *Floating Production Systems Type First used Depth (ft) Example Salt structures 1,000 to 4,999 ft 5,000 ft or more ULTRADEEP- WATER WELLS In the Gulf since 1987 Continental Shelf Gulf ofMexico Deep ocean floor Continental Slope Deepwater Horizon 4 3 2 1 1 2 3 4 since 1985. A er that incident, the PSA and the industry instituted a number of best practices for drilling exploration wells. ese include ri- serless drilling from stations on the sea oor, which prevents oil and gas from owing directly to a rig; starting a well with a small pilot hole through the sediment, which makes it easier to handle gas kicks; having a remote-controlled backup system for activating the blowout pre- venters; and most important, never allowing fewer than two barriers between the reservoir and the sea oor. " e decisions [BP] made when they had in- dications that the well was not stable, the deci- sion to have one long pipe, the decision to have only six centralizers instead of 21 to create the best possible cement job---some of these things were very surprising to us here," says Ognedal. e roots of those decisions lie in BP's cor- porate history, says Robert Bea, a University of California, Berkeley expert in both techno- logical disasters and o shore engineering. BP hired Bea in 2001 for advice on problems it faced a er it took over the U.S. oil companies Amoco and ARCO. One problem, Bea says, was a loss of core competence: A er the merger BP forced thousands of older, experienced oil eld workers into early retirement. at decision, which made the company more dependent on contractors for engineering expertise, was a key ingredient in BP's "recipe for disaster," Bea says. Only a few of the 126 crew members on the Deepwater Horizon worked directly for BP. e drilling operation itself was regulated by SEAFARING RIGS Floating rigs, first developed in the 1960s, have opened deep water to petroleum exploration. Floating platforms allow siphoning of oil from wells that can be many miles from shore. Scale varies in this perspective. The distance between Port Eads and the former site of the Deep- water Horizon is about 50 miles.