Posted on 06/03/2010 2:34:57 PM PDT by 7thOF7th
With each gallon of oil that leaks out of the hole in the Gulf, a vacuous cavity is forming and no longer providing structural support to the subterranean oil deposit. It is this very pressure that pushes the oil out of the hole. Under normal operating conditions sea water or heavy mud is used to replace the volume of oil extracted. If nothing is filling the space of the leaking oil, a catastrophe of immense and long lasting impact could occur. If the ceiling of the subterranean cavern collapses, it will release the entire oil deposit into the Gulf of Mexico. This would be biblical in size and scope of disasters as over a billion gallons of crude oil and gas are released all at once. IMHO
(Please, no 50000 gigabyte .PDF files!)
If the DP has dropped back down into the well, what they can do then, even if they don't have 100% seal on the wellhead, is to rig a snubbing unit at surface and run 1" wash pipe into the new riser and down into the surface casing and pump kill mud (18 pounds/gallon should do it).
Problem is, they've probably got multiple flowpaths from the formation face to surface: one up the old DP, one in the production string around the DP (what's left of it), and another behind pipe up through one of the liner laps into the production-casing/surface casing annulus to surface, which is how the gas got to surface in the first place.
They would sequentially have to fill all three of those flowpaths with heavy kill mud.
Oh, and there's also the problem that they're still communicated behind pipe with the lost-circulation zone above 12,000' MD, which stands ready to take their kill mud the same way it took their mud originally when they lost circulation at TD. Which would compromise their new hydrostatic regime they're trying to set up and allow the well to flow behind pipe again.
It's sort of a hydrodynamic version of whack-a-mole. Whack this one, the other one pops up. Gas has too many flowpaths to surface, it's gonna bite you.
BS!!!
Until they put in the offshore rigs in So, California thousands of barrels of oil boiled up for hundreds of years daily and nothing colapsed.
The oil rigs relived the gas pressure and reduced the flow to a low volume today.
In the 40s and early 50s when I was going to the beach there wasn’t a beach in So California that wasn’t covered with tar.
So much oil used to flow naturaly that the Spanish beached their ships at Golita to tar the bottoms 400 years ago.
They cut off the top of the riser. There is no way to bolt a BOP Stack onto that. There has been a failure inside the BOP Stack. The Engineers know this and this is why they will not run drill pipe inside the 9-5/8 inch casing which in all probability they could not anyway. The failure in all probability is at the casing hanger for the 9-5/8 inch casing. The oil and gas is coming from the formation around the outside of the 9-5/8 inch casing. You could fill the casing up with cement and the well would still flow!
That well will flow until the relief wells are drilled into the production zone and they kill the well and fill it with cement. Hopefully BPs effort to attach the new riser assembly will collect the oil until they have killed the well.
Exactly! It is rare to find large cavities (caves, basically) full of oil, and those tend to be self-supporting and fill with water after the oil is gone.
I pretty much agree with LG’s analysis on this. Too many problems all at the same time. they might have trouble killing this thing from the bottom in fact.
As to putting a new BOP on top of the one already in place, I think they are afraid that the integrity of the topside well structure has been compromised too much for that. Remember that 5000’ of riser and the deepwater horizon itself were anchored to that pivot point for two days before and during the sinking. That well head has withstood many extreme loads already and, if it were me making the decisions, I sure wouldn’t want to put any more stress on it at this point.
What are the chances of THAT? My dad sold for Cameron for years (long ago) and in all my years of selling drilling equipment I've never heard of them all failing.
Good point.
That has had me wondering, too.
I think it may have been a question of having had the chance to close them once the blowout was apparent before the explosion.
I have been wondering why no one has attempted to hook up lines to the existing BOP and close those rams (or maybe they did), but there may be other problems.
Is there still drill pipe in the hole?
Can another stack be bolted onto the existing wellhead if the current BOP was removed? Is the casing in good enough shape to withstand the pressure? I am sure these questions have been asked elsewhere.
I know that a ROV has tried to close the rams.
No. The oil is in porous rock that is being squeezed out due to the influx of sea water. There is no cavity being formed.
The question is one of whether or not there is junk in the hole. It'd be a real bugger to get stuck in there with the well blowing out--and there would be significantly less ability to capture the oil coming out.
Then there's the mud. If they needed 16.8# to hold it with the mile of riser, they'd need somewhere between 19# to 22# to hold it without a riser (5,000 ft. less column), and anything short of bottom would take heavier yet. Pretty tough to kill it halfway down...even with the ECD, and you'd lose the mud without a way to capture it at the wellhead.
With all that went on, I wouldn’t be very surprised if there is some mechanical damage in there somewhere.
Pretty small. I am also puzzled by this. I keep wondering if when the cement job failed and they had about 8000 psi on the outside of the 9 5/8 casing that perhaps casing was forced up into the BOP Stack. However, the shear rams should have been able to cut that also.
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