Tests on BP Well Blowout Preventer Confirm Redesign a Necessity

Yesterday, the Department of Interior released Det Norske Veritas’ (DNV) report on the forensic testing that it conducted on the blowout preventer (BOP) that failed to shut in BP’s blown out Macondo well almost a year ago.  I’m still going through the 500-plus page report to find answers to my many questions about the failed BOP, but I do agree with the over riding recommendation to the industry from DNV:

“The finding of these studies should be considered and addressed in the design of future Blowout Preventers and the need for modifying current Blowout Preventers.”

DNV was addressing a recommendation to the industry that it study the causes and results of “elastic buckling” of the drill pipe within the Macondo BOP that pushed it to the side of the wellbore, preventing the blind shear ram, or the ram that is supposed to cut the pipe and seal the well, from doing so.  During the time of the blowout, the forces within the well were so strong that it lifted the drill pipe, causing it to buckle and push over to the side of the BOP bore, positioning it outside of the shearing faces of the rams.

The long-delayed DNV report is very thorough and highly technical.  I’ve been wading through it for several hours and will write about some of their more detailed conclusions in a later post, but I wanted to make this one key point right now:  The US Government is currently issuing permits to drill knowing full well that operators are using blowout preventers that are insufficiently designed to shut in blown out deepwater wells.  I have been talking about this fatal flaw for months now.  The industry and Gulf Coast politicians have been applying unrelenting political pressure on the government to let deepwater drillers go back to work, and it has rationalized its capitulation saying that the industry has demonstrated its ability to contain deepwater blowouts with new equipment designed to do that.  That’s not really true, of course, since this new equipment is untested in real life conditions.  Add this to the now well documented flawed BOP design, and we have another potential catastrophe on our hands.

I fully understand the many issues surrounding further delaying drilling the deepwater.  Thousands of jobs hang in the balance and our dependence on foreign oil is expanding above already dangerous levels.  Since our elected leaders have failed for over 40 years to establish a comprehensive energy policy, our need for deepwater development has become critical to allow us to maintain at least some control over our own energy destiny.  The elephant in the room, though, is the now documented unreliability of subsea BOPs.  It is an incontrovertible fact, and one that the industry will argue vociforously against, that we are going back to work in the deepwater with unsafe equipment.  Since the government is issuing drilling permits anyway, it is critical that they be issued only to operators who have virtually unblemished track records in the deepwater.  Thankfully, the first new drilling permit was issued last week to Shell, who represents the gold standard in deepwater operations.  You’ll recall that during the height of the crisis last summer, BP’s decisions and design were unfavorably compared to those of Shell’s.  Shell getting this first permit gives me some level of comfort, but it is just one of about a dozen deepwater operators.  I’m not as comfortable with others.

Until we face the fact that we have been driven into the deepwater because of our lack of a national energy policy, and learn from the failures in the previous catastrophe, we are only doomed to repeat that very same catastrophe. 

Bob Cavnar, a 30-year veteran of the oil and gas industry, is the author of Disaster on the Horizon: High Stakes, High Risks, and the Story Behind the Deepwater Well Blowout. He is CEO of Luca Technologies.



  1. Gramiam44 says

    Just saw your appearance on Rachel Maddow, Bob! Factual, honest and informative as usual! You are the go to guy for oil issues with very good reason. Kudos to our mutual blogger friend Juanita Jean for tooting her horn for you!

  2. Oilacct says

    Until such time as BOP’s are available with an extra set of shear rams, which should have happened a long time ago, just to prevent an inability to shear tool joints, would a requirement to use appropriately heavy mud provide enough risk mitigation? From everything that’s been published, it seems like BP could have avoided the blowout by not displacing the heavy mud from the hole. I read a few comments from drillers who said it’s too big a pain to go through the mud to complete the well, but it seems to me that it’s prudent to leave it in.

  3. Fishgrease says

    Bob, you were talking about this very soon after the blowout itself. I don’t remember which show you were on. They asked you about removing the moratorium (which had only just then been placed on deepwater) and you said no, this would require a complete redesign of BOPs and other subsea equipment. I remember agreeing, but also, I was surprised anyone was talking about removing the moratorium when the well was still gushing. I’m certain this was back before they’d captured a drop via any process, so it was very early on in the disaster.

  4. WindorSolarPlease says

    Thank you for writing this..
    I agree..If nothing is learned from this..we are only doomed to repeat that very same catastrophe.

  5. Bob Cavnar says

    Short cutting is what generally leads to these kinds of incidents. They could have certainly left the mud in the riser until the lock down ring was set and the top cement plug in place. Had they done these two things, likely the well would not have gotten away from them, bad cement or not. If they had waited another day, they could have also run a bond log to determine quality and top of cement.
    Like they say, the best way to control a blowout is to not have one in the first place.

  6. Dr Juan says

    The DNV report completely overlooks the fact that nearly all of the seal rubber is gone. There must be something about the drilling fluid environment and thermal conditions during the blow out that causes the rubber to weaken, degrade or decompose. This is why none of rams, even though they did close all failed to seal. And the explanation that the drill pipe buckled way off to the side of the BOP bore did not make any sense to me. The drill pipe is very stiff and was centralized by the closed annular 20 feet above the shear ram and by the upper multiram just ten feet below. If I read the report correctly, these were both closed and are capable of keeping the pipe on the bore center line. And both were thought capable of actually stopping the flow. Of course after the blowout occurs, with little fluid left in the well, the pressure on the rams may have been well above the BOP capability. Next time close the rams sooner guys!

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