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Permalink Reply by Martin on June 21, 2010 at 4:01

This is the first page/screen of the article:


It was the last line of defense, the final barrier between the rushing volcanic fury of oil and gas and one of the worst environmental disasters in United States history.

Its very name — the blind shear ram — suggested its blunt purpose. When all else failed, if the crew of the Deepwater Horizon oil rig lost control of a well, if a dreaded blowout came, the blind shear ram’s two tough blades were poised to slice through the drill pipe, seal the well and save the day. Everything else could go wrong, just so long as “the pinchers” went right. All it took was one mighty stroke.

On the night of April 20, minutes after an enormous blowout ripped through the Deepwater Horizon, the rig’s desperate crew pinned all hope on this last line of defense.

But the line did not hold.

For days, technicians and engineers worked furiously to figure out why, according to interviews and hundreds of pages of previously unreleased notes scrawled by industry crisis managers in the disaster’s immediate aftermath.

Engineers sent robotic submersibles 5,000 feet deep to prod the blind shear ram, nestled in the bosom of a five-story blowout preventer standing guard over the Macondo well.

They were driven on, documents and interviews reveal, by indications that the shear ram’s blades had come within a few maddening inches of achieving their purpose. Again and again, they tried to make the blades close completely, knowing it was their best chance to end the nightmare of oil and gas billowing into the Gulf of Mexico.

“If that would’ve worked,” a senior oil industry executive said of the blind shear ram, “that rig wouldn’t have burned up and sunk.”

Much remains unknown about the failure of this ultimate failsafe device. It continues to be a focus of inquiries, and some crucial questions will not be answerable until the blowout preventer is recovered from the sea.

But from documents and interviews, it is possible to piece together some of the decisions and events that came into play when the Deepwater Horizon most needed the blind shear ram.

Engineers contended with hydraulic fluid leaks that may have deprived the ram of crucial cutting force. They struggled to comprehend what was going on in the steel sarcophagus that encased the shear ram, as if trying to perform surgery blindfolded.

They wondered if the blades had by chance closed uselessly on one of the nearly indestructible joints that connect drilling pipe — a significant bit of misfortune, given a decision years before to outfit the Deepwater Horizon’s blowout preventer with just one blind shear ram when other rigs were already beginning to use two of them to guard against just this possibility.

But the questions raised by the failure of the blind shear ram extend well beyond the Deepwater Horizon.

An examination by The New York Times highlights the chasm between the oil industry’s assertions about the reliability of its blowout preventers and a more complex reality. It reveals that the federal agency charged with regulating offshore drilling, the Minerals Management Service, repeatedly declined to act on advice from its own experts on how it could minimize the risk of a blind shear ram failure.

It also shows that the Obama administration failed to grapple with either the well-known weaknesses of blowout preventers or the sufficiency of the nation’s drilling regulations even as it made plans this spring to expand offshore oil exploration.

“What happened to all the stakeholders — Congress, environmental groups, industry, the government — all stakeholders involved were lulled into a sense of what has turned out to be false security,” David J. Hayes, the deputy interior secretary, said in an interview.

Even in one significant instance where the Minerals Management Service did act, it appears to have neglected to enforce a rule that required oil companies to submit proof that their blind shear rams would in fact work.

As it turns out, records and interviews show, blind shear rams can be surprisingly vulnerable. There are many ways for them to fail, some unavoidable, some exacerbated by the stunning water depths at which oil companies have begun to explore.

But they also can be rendered powerless by the failure of a single part, a point underscored in a confidential report that scrutinized the reliability of the Deepwater Horizon’s blowout preventer. The report, from 2000, concluded that the greatest vulnerability by far on the entire blowout preventer was one of the small shuttle valves leading to the blind shear ram. If this valve jammed or leaked, the report warned, the ram’s blades would not budge.

This sort of “single-point failure” figures prominently in an emerging theory of what went wrong with the Deepwater Horizon’s blind shear ram, according to interviews and documents. Some evidence suggests that when the crew activated the blind shear ram, its blades tried to cut the drill pipe, but then failed to finish the job because one or more of its shuttle valves leaked hydraulic fluid.

These kinds of weaknesses were understood inside the oil industry, documents and interviews show. And given the critical importance of the blind shear ram, offshore drillers began adding a layer of redundancy by equipping their blowout preventers with two blind shear rams.

Comments and observations?

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Permalink Reply by Martin on June 21, 2010 at 4:27

Shale Geo --

Have you read the article?

j.

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Permalink Reply by Dorcheated A1 on June 21, 2010 at 4:54

Thanks Jay, if you didn't I was.

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Permalink Reply by Martin on June 21, 2010 at 5:04

What errors are there? That's one of the reasons I posted the article. To find errors.

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Permalink Reply by Martin on June 21, 2010 at 5:10

Please note that I posted only the first screen/page of the article. There are eight more at the linked site.

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Permalink Reply by Martin on June 21, 2010 at 6:25

Jay --

The following is from page 7 --- the attempts to activate the blind shear after the sinking of the platform continues to page 8.

"It would be 27 hours after Mr. Pleasant abandoned ship before engineers could make their next effort to trigger the blind shear ram, according to BP documents.

Within the first few days, engineers had already begun to wonder whether a leak of hydraulic fluid had crippled the ram. “May have had leak & have lost pressure,” one entry reads. Using a robotic submersible equipped with a hydraulic pump, they injected seawater into the blind shear ram, hoping to drive its pistons and blades closed. But the pump did not have nearly the needed strength; it could not pump water fast enough to budge the blades.

Industry studies had highlighted the problem of submersibles without sufficient strength years earlier. Now, as BP and Transocean officials searched the globe for more powerful ones, engineers plotted out a plan essentially to trick the blind shear ram into closing.

When the rig’s control panels fail, two separate backup systems, the deadman and the autoshear, are supposed to close the blind shear ram automatically. The deadman is designed to close the shear ram if the electronic and hydraulic lines connecting the rig to the blowout preventer are severed.

An underwater robot cut several lines at 2:45 a.m. on April 22.

Nothing happened.

The situation was rapidly deteriorating. “2 explosions around 3:30-4:00 this morning & rig listing at about 35 degrees,” a crisis manager wrote. “High risk of sinking.”

The autoshear is designed to trigger the blind shear ram if a rig drifts out of position and yanks its riser loose from the blowout preventer.

At 7:30 a.m., a submersible cut a firing pin on the blowout preventer, simulating the rig’s pulling free. This time, the blowout preventer shuddered, as if struggling to come back to life. “L.M.R.P. rocked & settled,” one note says, referring to the top half of the blowout preventer. But after a few moments, as oil continued to flow, it became clear that this, too, had failed.

Soon after, the Deepwater Horizon sank.

Stunning Discovery

The deadman, the autoshear and the underwater robots constitute the critical backup systems that have given regulators and oil industry officials great confidence that no matter what, they could always find a way to activate their last line of defense." -----

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Permalink Reply by Martin on June 21, 2010 at 11:10

Jay --


There does seems to be plenty of proof to support human error -- ignoring the previous indications of well problems, the question of the cementing operation, etc. The basis of the errors does look like corner cutting to reduce costs.

What do you suspect?

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