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Discovery of second pipe in Deepwater Horizon riser stirs debate among experts

Published: Friday, July 09, 2010, 9:40 PM

For the first time Friday, the Coast Guard and BP acknowledged that a mysterious second pipe, wedged next to the drill pipe in what remains of the Deepwater Horizon's riser, is fouling up the works where the well is spewing hundreds of millions of gallons of crude oil into the Gulf of Mexico.

gulf_oil_blowout_preventer_two_pipes.JPGView full sizeTwo pipes are seen in this view of the riser just above the Macondo well's blowout preventer, captured on BP video in June, just after it was cut.

"We used a diamond saw and we got inside. We found there was actually two sets of drill pipe there," said retired Adm. Thad Allen, the top U.S. Coast Guard official overseeing the response to America's worst-ever oil spill.

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Some experts say a second piece of drill pipe in the riser could have prevented shear rams on the rig's blowout preventer from sealing the well and permanently cutting off the flow of oil after the April 20 explosion. The presence of two pipes could have also contributed to BP's failure to make a clean cut on the riser when securing the existing containment dome, inhibiting its ability to collect the maximum amount of oil.

It "presumably fell down beside it as a result of the explosion and the riser pipe being bent over," Allen said. He noted that the second pipe does not have oil shooting from it.

BP officials said late Friday that they believe the second pipe is drill pipe. Pictures show it is similar in diameter to the known drill pipe.

While Allen said he believes the second pipe fell from above, some experts have advanced another explanation. They believe poorly cemented casings -- tubes that are supposed to form solid walls down thousands of feet of the well bore -- may have been dislodged by the blast of natural gas that shot up out of the well and above the sea floor.

If that's what happened, the piece of pipe would have gone into the blowout preventer, the 450-ton tower of valves and pistons that sits on top of the well head and is supposed to shut off the well in an emergency. The Deepwater Horizon's blowout preventer failed to cut through the pipe that ran through it, and subsequent efforts to shut the so-called shear rams using remote-control submarine robots also failed.

Preliminary investigations have shown that other questionable decisions and well-design choices precipitated the blowout of a well that had been considered a "nightmare" by BP engineers. But the blowout preventer was the last-ditch way to save the rig from the explosions that killed 11 men and eventually led to the interminable leak.

The idea that a loose pipe shot up from deeper in the well and prevented the shear ram from closing has been espoused by such experts as oil industry investment banker Matt Simmons and Bob Bea, a University of California at Berkeley engineer leading a scientific investigation into the blowout. But others have wondered if the mystery pipe isn't just a section of the same drill pipe that came loose, or even a pipe that fell down the riser from the rig 5,000 feet above.

The Coast Guard's acknowledgement of the two metal tubes Friday -- and a subsequent reference by BP to its plans to tie the two pipes together as the company installs a new oil collection system over the shaved-off riser -- actually comes more than a month after the Department of Energy noted the existence of two pipes using special imaging technology. At the time, BP dismissed the Energy findings as "impossible" because only one pipe in sections was used for drilling, a Tribune News Service story reported last month.

Video images of the riser when it was cut in early June clearly showed the two pipes, raising speculation on blogs. Allen said the second pipe also led to a jagged cut on the larger riser pipe, forcing the response team to use the loose cap with a rubber seal. And now, the two pieces are forcing the team to spend several days tying them together and clearing the way for a new, hopefully more solid connection.


Business writers Rebecca Mowbray and Jaquetta White contributed to this report. David Hammer can be reached at dhammer@timespicayune.com or 504.826.3322.


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fldr11 July 09, 2010 at 10:15PM

another puzzle in bps bunch of puzzles.

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TinFoilHatGuy July 09, 2010 at 10:22PM

The second pipe was hiding in the grassy knoll.

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daeschler July 10, 2010 at 2:39AM

If the BOP is left "cemented in" after the well kill, then goes the evidence... a bit like the black box too deep to recover.

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muspench July 10, 2010 at 10:11AM

See, they should know by now what sort of pipe it is anyway. They cut the riser and both pipes before putting the LMRP on, so there's a sample of the second pipe lying on the seabed still inside the riser. All they have to do to retrieve it is make another cut farther along, then bring the section to the surface.

Is it standard practice to leave the BOP down there? I would certainly think not, because I know they're reused (and tremendously expensive).

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daeschler July 10, 2010 at 10:58AM

Yes you could squeeze the riser further up and pick up a 20 ft section so all evidence will be on deck, assuming the riser has not disappeared in soft liqified sea bed around the well.

No one leaves BOP on seabed, but it may be difficult to retrieve at later date after well is killed.
Obviously they have taken the "safest" route to unbolt the flange rather than release the riser connector with an ROV hyd.hotline , I guess it is so bad that the least they distrurb the better it may hold.

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muspench July 10, 2010 at 12:49PM

But if they cemented in the BOP, would that mean they have to leave it in place? I know when they pumped drilling mud in from the top, that went through the BOP. When they pump cement in from the bottom, how far up will it go? Thad Allen talked about the new LMRP they're attaching this weekend, which will fit more closely, yesterday. He said, "[I]f we can get the cap on and we can seal it and maintain the pressure, that will increase our chances of more successfully capping the well below because there will be back pressure against that mud." He means the mud they'll pump in first during the bottom kill before they pump cement.

So I would think the cement would fill everything under the LMRP, but I don't know. If the cement job does leave cement in the BOP, could you take the BOP away without disturbing the remaining cement in the wellbore?

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daeschler July 10, 2010 at 2:50PM

The way they proceed at this stage is with only one thing in mind is to kill the well, and limit further ops. expenses and damages . Probably right who cares about a 3MM $ BOP, most likely wrecked (controls) damaged with abnormal stresses generated by a 5000 ft riser bending over the top of it.
They are not going to remove a BOP ( fully reimboursed to the drilling company by insurances) full of junk and drill pipe(s) , cement , mud , junk shot ect...off the sea bed and just to had more expenses and risks ? Unless it becomes a legal requirement to obtain evidence of the failures ?
I am amazed the well head is still there ? very strong design to cope with bending moment and drive off. May be a new rig has been ordered already in an Asian shipyard with a new BOP, so no time is wasted ?

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muspench July 11, 2010 at 8:41AM

Yes, it was an old BOP to begin with. Transocean bought it from Cameron, and as I recall it hadn't even been inspected since 2005 (!). Given its age and condition, it's virtually worthless... except for the evidentiary value. If it were up to me, I'd make them haul it up for examination, but frankly the government has been far too lenient with BP thus far, letting them direct the containment effort, so I'm wondering whether anyone will force them to recover it.

I know the government has been prodding BP to move faster-- we wouldn't be seeing this cap switch yet if Thad Allen hadn't demanded a quicker timetable from Bob Dudley-- so they may be controlling the process more than is generally apparent. Yes, it's very surprising there's still a connection between the BOP & the well itself; I would have expected oil to be escaping from the seabed around the well by now, honestly.

Here's what struck me: there's a new BOP built into the LMRP they're going to attach. They have the two-pipe situation right in that spot, so they're going to bundle the two pipes before attaching the LMRP. The pipes are not sticking out very far, so they won't reach into the BOP, which couldn't shear & seal two at a time anyway. It sounds like the BOP has a closed position it can take that doesn't require the existence of an actual pipe, because they're definitely planning on shutting the well in using the new LMRP. I'm just not sure why a BOP would be used on the top rather than just designing a closed-in LMRP in the first place. :)

---I'm appending this note to my posts for a few days.
Note: Please don't be confused by any comments posted recently using my name that weren't made using my account. There was a problem last night, and the simple way to make sure a comment is really mine is this: My name, muspench, is also my index page name. Here's my full index page address: http://connect.nola.com/user/muspench/index.html . The fake index pages, thugallen2 and thugallen3, are NOLA Pundit accounts and they may still be up, but not permitted to post.

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5000miles July 10, 2010 at 6:40AM

Good one!! LOL!

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gvicknair July 10, 2010 at 10:49AM

LOL

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leapinleopard July 09, 2010 at 10:33PM

"...raising speculation on blogs?"

Cuz we don't have any watchdogs in our Corporate Media?

Cuz investigative journalists don't get their stories printed?

So what did the more reasonable Blogs say?

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muspench July 10, 2010 at 10:24AM

Here's a sample from theoildrum.com, at the time when the ROV was cutting the riser:

"kyzy on June 3, 2010 - 10:29am
Did anyone catch this? I just snapped an image from the Viking ROV1 feed that seems (to me at least) to show two pipes inside the riser.
Francis on June 3, 2010 - 10:49am
Sure looked that way to me. Similar diameter, but possibly different wall thicknesses. Almost impossible to work out why. The ROV was certainly taking a lot of trouble to get a clear look at the severed end.
Cue the conspiracy theorists.
On reflection, maybe. If the diamond saw had severed the DP, and the BOP shears had also severed the DP, the flow might have pushed the now free length of DP up into the region the shears were cutting. That would mean two pieces of DP in the cut. Would not explain why they appeared to have different wall thicknesses. Doesn't match the theory that the BOP shears stalled on a DP join.
kyzy on June 3, 2010 - 11:02am
The pipes are too mangled to tell if the walls have the same thickness. The one to the right of the image is crimped as you might expect. But, the left pipe is not, as if something "solid" in the pipe resisted the force of the shears to crimp it. You can also see that the riser is much more "squeezed" on the right side. I don;t subscribe to conspiracy theories. There is an explanation for everything, no?
The riser was bent and the only other cut to the riser was several feet downstream. I can't see how the remaining length of DP could have "moved" towards the BOP top if the diamond saw had severed the DP before stalling. The "second pipe" (if what I see is a second pipe) must have fallen in while the riser was still straight.
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indio192 on June 3, 2010 - 10:59am
To me also. Seems that if there are two parallel pieces of pipe inside the riser, then the BOP could not work properly. All the info describing how a BOP works assumes that there is only one pipe inside the BOP and the rams close around this pipe (or shear this pipe). If there are two parallel pipes, the rams can't make a seal. And the shear ram could possibly get jammed." (http://www.theoildrum.com/node/6551#more )

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danny.video July 09, 2010 at 11:22PM

Things we'll never know
1. Why BP insists on capturing rather than capping this.
2. Who was smoking the 2nd pipe?

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TinFoilHatGuy July 10, 2010 at 8:16AM

One thing is true. Capping from top could blow the stack. All experts agreed on that one.

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wispa July 09, 2010 at 11:32PM

Someones pulling our pipe

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