Skip to comments.BP's Deepwater Horizon - Static Top Kill vs. Bottom Kill: Weighing the Risks - and Open Thread
Posted on 07/30/2010 10:50:54 AM PDT by Ernest_at_the_Beach
Author's Note: Art Berman (aeberman) is an Oil Drum staff member and geological consultant whose specialties are subsurface petroleum geology, seismic interpretation, and database design and management. He has been interviewed on CNN and BNN about the Deepwater Horizon disaster. William Semple collaborated on this post. Mr. Semple is a drilling engineer and independent drilling consultant with 37 years of experience in the oil and gas industry. He worked for 16 years with a major oil company and has 24 years of experience as a drilling supervisor. He has been a guest contributor on The Oil Drum writing about the Deepwater Horizon (June 19, 2010).
A permanent solution to the BP Macondo blowout in the Gulf of Mexico may be achieved soon but there are risks. Admiral Thad Allen announced on Monday, July 26 that a static top kill would be attempted on August 2. The schedule may be accelerated to July 31 or August 1 according to an announcement today (July 29). The sealing cap has successfully stopped the flow of oil and gas from the well and the pressure continues to build slowly. Temperature at the wellhead has not increased, and seeps near the well are mostly nitrogen and biogenic methane unrelated to leakage. BP Senior Vice President Kent Wells technical update on July 21 explained these findings and showed how the well will be killed.
There are risks involved in both the top and bottom kill procedures. The purpose of this post is to describe those risks. There are two risks associated with the static top kill. First, it may not work at all and second, it may rupture the casing by pumping heavy mud under pressure (bull heading).
(Excerpt) Read more at theoildrum.com ...
Thought this might be interesting.
The top kill seems to stand a better chance, because now that the flow has stopped, they should be able to pump mud down the choke line at the top of the well, and fill the well with mud.
Before when they tried this, the well was flowing, so as soon as any mud entered the top of the well it was just swept away.
I feared that the intercepting well would have the same problem if the well were still flowing. Any mud that entered the bottom of the well would be pushed out of the top of the well by the flowing oil before enough of a mud column could be built up to overcome the oil outflow pressure.
Plus, the bottom intercept well runs the same risk of simply becoming a second gusher. And if it does, there is no place for a second intercept well to intercept the original gusher well.
I vote for top kill!
Seems that getting the oil out of this tap would be a whole lot easier than drilling a whole new well. Or is that too sensible for the obama regime?
Pro: Quicker and easier
Con: subject to pressures and no assurance other fissures in casing or well hole don’t exist or have possible rupture.
Pro: Damn near predictable result of closing off the well at the source.
Con: Very expensive and time consuming.
Either way works.
I believe the answer has two reasons why they cannot put the well into production.
1) The integrity of the well casing over the long term is still very much in doubt.
2) The Blowout Preventor is damaged and would have to be replaced before the well could go into production, and to remove it means gushing oil again. Also, once the BOP is removed, the connecting flange to the well casing may have been damaged from the rig toppling, and it is possible that a new BOP couldn't be fitted.
The safest thing is to cement up this well and start over.
“Con: Very expensive and time consuming.”
Isn’t it it mostly already done??
I thought they were within a feet feet of where they needed to go?
What does Barry think?
How about drilling a new well a few hundred feet away or half mile. Would that reduce the pressure? Could the go horizontal and get near the other well?
Boy a lot of penny wise pound foolish in this thing. BP saved a few bucks. This well was a gold mine if they had done it right the first time.
Technically, “not work at all” is not a risk, if it simply leaves you no better or worse off than you were before.
Blowing out the casing would be a problem, but from what I understand the pressure they would be using would be highly unlikely to blow out anything that is withstanding the current pressure.
But you could hardly make news by saying that things were likely to work or not cause any problems.
I would think one advantage of top-kill first is that when they have to pump mud into the bottom kill, they won’t have to release the oil that is in the main well to allow mud to flow up, since it will be full of mud.
I haven’t seen Barry O. giving a speech about how he and his experts have done anything else...
He be the one plugging the Hole.
He is A-Hole....
He is waiting on his teleprompter to tell him what to say...and it is busy today in Michigan.
BP is the one that does not wish to pump from the cap. The Feds are pushing them to do this. Once a measured flow from the well can be established, the Feds can hit BP with a $4800/barrel fine for the duration of the spill. Someone claimed this would be another $20 billion over and above their current liability.
Not in my understanding. Think of it this way, drill a pin hole into the bottom of a pool or even a tub. Would a second hole that size help?
“What does Barry think?”
He thinks he needs another vacation or a new set of golf clubs.
Most oil formations have multiple wells drilled into them to bring the crude topside. How much does one well relieve the pressure? Not much would be my guess and it’s only a guess.
Nothing says they won’t drill other wells at some point into this formation for production assuming they get gov’t okay. Also bet on the next one they won’t take the mud out of the hole and leave just sea water in the hole. This well wasn’t scheduled to be brought online for production until some years hence. That is why they where shutting it in at the time of the blowout.
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