Top Expert: Geology is “Fractured”, Relief Wells May Fail … BP is Using a “Cloak of Silence”, Refusing to Share Even Basic Data with the Government

Friday, August 20, 2010
By Paul Martin

Washington’s Blog

Few people in the world know more about oil drilling disasters than Dr. Robert Bea.

Bea teaches engineering at the University of California Berkeley, and has 55 years of experience in engineering and management of design, construction, maintenance, operation, and decommissioning of engineered systems including offshore platforms, pipelines and floating facilities. Bea has worked for many years in governmental and quasi-governmental roles, and has been a high-level governmental adviser concerning disasters. He worked for 16 years as a top mechanical engineer and manager for Shell Oil, and has worked with Bechtel and the Army Corps of Engineers. One of the world’s top experts in offshore drilling problems, Bea is a member of the Deepwater Horizon Study Group, and has been interviewed by news media around the world concerning the BP oil disaster.

Washington’s Blog spoke with Dr. Bea yesterday.

WB: Is BP sharing information with the government?

Bea: No. BP is using a “cloak of silence”. BP is not voluntarily sharing information or documents with the government.

In May, for example, Senator Boxer subpoenaed information from BP regarding footage of the seafloor taken before the blowout by BP’s remotely operated vehicles (ROVs). We still have not received a response 12 weeks later.

[Bea subsequently clarified that he's not sure whether BP has failed to release the information, or Senator Boxer's committee has sat on the information. My bet is on BP. Indeed, BP has refused to answer some very basic written questions from Congressman Markey, chair of the Select Committee on Energy Independence and Global Warming. See this and this. Indeed, it is unclear whether BP is sharing vital details even with Thad Allen, Secretary of energy Chu, or the Unified Command].

WB: Might there be problems with the relief wells? I know that it took a couple of relief wells to finally stop the Ixtoc leak, and it has taken as many as 5 relief wells to stop some blowouts.

Bea: Yes, it could take repeated attempts.

WB: Are there any conditions at BP’s well which might make killing the leak with relief wells more difficult than with the average deepwater oil spill?

Bea: That’s an interesting question. You have to ask why did this location blow out when nearby wells drilled in even deeper water didn’t blow out.

You have to look at the geology of the Macondo well. It is in a subsalt location, in a Sigsbee salt formation. [For background, see this and this]

The geology is fractured.

Usually, the deeper you drill, the more pressure it takes to fracture rock. This is called the “fracture gradient”.

But when BP was drilling this well, the fracture gradient reversed. Indeed, BP lost all pressure as it drilled into the formation.

WB: Is it possible that this fractured, subsea salt geology will make it difficult to permanently kill the oil leak using relief wells?

Bea: Yes, it could. The Santa Barbara channel seeps are still leaking, decades after the oil well was supposedly capped. This well could keep leaking for years.

Scripps mapped out seafloor seeps in the area of the well prior to the blowout. Some of the natural seeps penetrate 10,000 to 15,000 feet beneath the seafloor. The oil will follow lines of weakness in the geology. The leak can travel several horizontal miles from the location of the leak.

[In other words, the geology beneath the seafloor is so fractured, with soft and unstable salt formations, that we may never be able to fully kill the well even with relief wells. Instead, the loss of containment of the oil reservoir caused by the drilling accident could cause oil to leak out through seeps for years to come. See this and this for further background].

WB: I know that you’ve previously said that you’re concerned that there might be damage to the well bore, which could make it more difficult for the relief wells to succeed.

Bea: Yes, that’s still a concern.

WB: I have heard that BP is underestimating the size of the oil reservoir (and see this). Is it possible that the reservoir is bigger than BP is estimating, and so – if not completely killed – the leak could therefore go on for longer than most assume?

Bea: That’s plausible.

The Rest…HERE

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