Update: Expert Report Deplores Poor Decisions Leading to Gulf Oil Spill

Dick writes about Earth and planetary science for Science magazine.

A series of ill-advised decisions by operators that saved time and money likely contributed to the eventual blowout and explosion that oiled the Gulf of Mexico this year. That's the preliminary conclusion released today by a committee of the U.S. National Academy of Engineering and the National Research Council, which found nothing inherent in deepwater drilling or the geology of the gulf's offshore oil and gas reservoirs that would have doomed the Deepwater Horizon.

The committee's prime example of a fateful decision was drillers' relying on a newly installed cement plug in the well despite the plug having failed three successive tests of its reliability. The cement was intended to seal the well against inevitable deep pressures, but the test failures were "an irrefutable sign that the cement did not establish a flow barrier," the report states.

The report lists eight other less pivotal decisions that may have contributed to the accident. They range from an unduly simplistic approach to cementing a well that penetrated a complex geologic structure to not installing additional hardware that would have helped back up the cement barrier. "All these decisions appear to have been made in a direction that led to reduced schedule and therefore reduced cost," the committee chair, engineer Donald Winter of the University of Michigan, Ann Arbor, said at today's press conference. The report notes that the lack of "a suitable approach for managing the inherent risks, uncertainties, and dangers" prevented anyone—from drillers on the platform to federal regulatory agencies—from reversing those decisions before they led to catastrophe.

That decision process was overly centralized, the committee found. It notes testimony before another of the 14 groups investigating the accident that revealed that a single BP "wells team leader" was responsible for minimizing cost and staying on schedule as well as for ensuring well safety. And that leader had no "standard practice" to guide tradeoffs between containing costs and ensuring safety, it said. The committee will make specific recommendations in its final report, due next June, that encompass "the full range of factors affecting the safety of drilling operations."

For more on the gulf oil spill, see our full coverage.

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