Source:
WSJIn recent years, oil giant BP PLC used a well design that has been called "risky" by Congressional investigators in more than one out of three of its deepwater wells in the Gulf of Mexico, significantly more often than most peers, a Wall Street Journal analysis of federal data shows.
The design was used on the well that exploded in the Gulf of Mexico on April 20, killing 11 workers and causing America's worst offshore oil spill. The only other major well design, which is more expensive, includes more safeguards against a natural-gas blowout of the kind that destroyed the Deepwater Horizon.
A Journal analysis of records provided by the U.S. Minerals Management Service shows that BP used the less costly design—called "long string"—on 35% of its deepwater wells since July 2003, the earliest date the well-design data were available. Anadarko Petroleum Corp., a minority partner of BP's in the destroyed well, used it on 42% of its deepwater Gulf wells, though it says it doesn't do so in wells of the type drilled by BP.
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A long-string design is cheaper because a single pipe runs the length of the well and can be installed in one step. But it also can create a dangerous pathway for natural gas to rise unchecked outside the pipe.
The alternative, known as liners, is seen as safer because it has more built-in places to prevent oil or gas from flowing up the well uncontrolled. "There are more barriers, and the barriers are easier to test," says Gene Beck, an engineer and professor at Texas A&M University.
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http://online.wsj.com/article/SB10001424052748704289504575313010283981200.html?mod=WSJ_hpp_LEADSecondNewsCollection
BP advertised that Horizon was the first well to be drilled so deep. A huge deal for them. So what did they do, they used a cheaper well. How does that makes sense.