Thinking about the BP Oil spill...

[cabinetman]

I'm wondering if some kind of heavy duty air bag (or hydraulic) could be inserted in the pipe and blown up (expanded).
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[chopnhack]

I just checked the spill cam....my first thought was "funnel" can we put a large funnel around the opening and then perhaps as cman said inflate air bags around it to seal off the opening? As for the increasing the pressure into the surrounding strata, are we able to pump this oil up to surface fast enough to balance out the pressure? According to the new estimates 1.3-2.5 million gallons are flowing a day from this pipe... this must have been one mother load of oil and now it seems to have gone to pot.

[jabe]

I feel for all the people living & working there. Losing your livlihood, damaging the environment, killing all the wildlife, what a big mess with no solid solution. I just hope BP's pocket is deep enough to pay for all the clean up, compensation for all the people who lost their jobs & business. That 20 bil is not enough to cover all the damages to the environment & people affected by this mess. Now a storm is coming this will spread the oil out to more places, no gulf coast country, state and even the east coast might get some of this sludge. Why don't the UN get involved, this is a International problem, not only America's.

[Cochese]

I think you're dealing with three major issues with deploying any solution:

1) depth
2) pressure
3) cold

You can't get any humans down there to do any fine tuning on any method, robots have to do it all. You're dealing with pressures different than the surface, so different methods need to be employed. You also have potential ice buildup on anything you do, which is what stopped the very first attempt.

My immediate thought would be to extend a double-headed ram by hydraulics and seal both sides. But I have no idea if the hydraulics or seals would work with those pressures and that temperature.

[chopnhack]

Sure, they could potentially pinch off the pipe, but as others have mentioned the resulting increase in pressure behind the pinch could lead to a blowout of the drill hole since they didnt take the time to cement it properly.

[LCHIEN]

The problem is that they think the well itself is very fragile. One the cement job is known faulty. Two the BOP stack is actually bent - the riser collapsing on it may have bent the casing its attached to when the rig sank. Three the well have been flowing at very high velocity rates, uncontrolled for two months now and they are worried about the possibility of pipe erosion weaking the pipe.

The reservoir is at very high pressure (probably around 22,500 psi assuming 20 ppg mud and 18,000 feet)
The column of oil in the pipe has a head of around 7500 psi leaving about 15,000 PSI that would appear at the top of the well if simply stopped up with no flow.
So simply stopping it by crimping, plugging the pipe etc is like closing off a water hose that has a weak wall - the pressure may rupture the walls and then you'd have an undergroiund blowout where gas and oil would be coming up through fissures in the ocean bottom - essentially un-cappable and not capturable.

By capturing the existing flow into the temporary riser with limited backpressure the presure on the casing is minimized and lowers the risk of losing the well to an underground blowout which is even worse (yes it can get worse). Underground blowouts have been known to leak so much gas into the water that the water density plunges and ships start to sink. They could potentially lose the Q4000 drillship, the Transocean vessel accumulating the oil and all the support boats driving the ROVs and cameras.... makeing the original accident look puny.

[jackellis]

Thanks for the background information. If the well was damaged, maybe having the blowout preventer fail was better than having it work properly and in the process, create a bigger problem.

[LCHIEN]

that depends.
If the blowout preventer had closed properly after the first explosion, then
1. the casing would not be eroded by months of continuous high velocity flow
2. the rig fire may have been extinguished (not fed by more gas and oil) and the rig not sinking and damaging the casing/BOP stack

Then perhaps closing the BOPs would not have been so risky at that point.

[gsmittle]

It strikes me dumb how governors of states affected by the BP spill are outraged by the environmental damage one minute and beating on the Feds to remove the deepwater drilling moratorium the next. Perhaps it's because I'm an engineer and we have certain character defects like a propensity to be rational…

To quote one of my professors in grad school: "Never underestimate a person's ability to hold two mutually contradictory ideas at the same time."

I'm constantly amused by radio talk-show callers who say, "Look, it's simple. All they have to do is …" NOTHING is ever that simple.

I just wish somebody would find a way to cap this sucker.

g.

[LCHIEN]

...It strikes me dumb how governors of states affected by the BP spill are outraged by the environmental damage one minute and beating on the Feds to remove the deepwater drilling moratorium the next. ...
I wonder what Loring has to say? He's the resident expert on this topic.

The rationale is simple and not dumb if you accept two facts:
1. That the Blowout was caused by a series of corporate and human failures, not by failures of technology. In this case there is a strong possibility, even liklihood, that the intial blowout and loss of the rig was caused by certain oil comany operating the rig to not have applied the best judgement according to safety vs. saving money and time pressures. And that the subsequent failure of the BOPs and the release of oil was because of inadequate maintenance and foolish decisions again driven by costs and time.
2. That the gulf states main businesses are seafood, tourism (including hunting fishing) and oil exploration/production (in no particular order). Moratorium on offshore drilling will likely cost 100,000 jobs directly or indirectly and there's already, lets say 100,000 jobs or more at risk from closing of prime fishing areas and prime tourist locales. You've already take two serious hits; do you want the third, too? The kicker is that if the rigs move to other areas of the world during the moratorium, the transit costs are expensive and the contracts long, so it will be many years before they return, if ever. So the loss of jobs will be for years, not just 6 months.

Basically The environmental damage has cost half their constituents jobs or reduction of business. Then A drilling Moratorium will cost the other half of their constituents their jobs or business.

I think that requiring operating companies to have certifications of some sort to the effect that their BOPS are in fact working in all respects and furnish written weekly reports on their state of readiness before restarting drilling will provide a margin of safety. Missing rams, undersized rams, leaking hydraulics and dead batteries (reasons the BOPs at Deepwater Horizon did not close) would not be permitted.

[Rand]

It's looking more and more like they won't be able to stop the leak until they get the relief wells drilled. They said that from the beginning. The last timetable I heard was for completion of the relief wells in August.

[tommyt654]

If that storm hits the area in question I think it,ll be more like Sept before that,ll happen. Hey Loring any thought on Gasland?

[LCHIEN]

gasland

If that storm hits the area in question I think it,ll be more like Sept before that,ll happen. Hey Loring any thought on Gasland?

I didn't know what Gasland was (a movie) until I googled it.
Apparently it's a semi-documentary about worst case what could go wrong.

It has to do with natural gas productin in the northeast (teh Marcellus Shale formations) which are 8900 feet below butin some cases breaks the earths surface.

Natural gas production is enhanced esp in tight shale by hydraulic fracturing, one of the tools of oil/gas producers in which they inject fluids solids or gases at high pressure in the formation causing it to break down and allow easier flow of the oil/gas to the well bore.

I understand the risks esp in shallow wells is that the gas might follow new unintended paths created by fracture... to escape into the water table (gasifying the water e.g. flammable tap water scares) and pooling in low lying areas when vented from fissures - an explosive or even asphixiation hazard.

The gas and water acquifer are trapped (water above and gas below) non-porous layers and the water and gas will be in porous layers usually they are separated by quite a few layers in geologic time - layers being like growth rings in trees.



http://en.wikipedia.org/wiki/Hydraulic_fracturing
gives more info on the hazards currently in the news.

I suspect properly done gas reservioirs are way deep and will not affect the water and surface.... movies like this are often done to scare people with 5% truth and 95% exaggeration, but then, I haven't seen the movie, he might be right on.

Fracturing is not an area I've been exposed to much. I did log a fracturing process once with downhole seismic equipment during a fracturing operation. Lots of big powerful trucks running their pumps at maximum RPM for 15 minutes at a time - very loud and impressive.

[unknown poster]

I read that they intended to drill a new well to intersect this one near the oil resevoir. This new well would pump mud and concrete to seal the well, similar to the top kill but pumped from the bottom instead of the top.

If the cement around the well pipe is questionable, will sealing the pipe from the bottom cause the same risk of leakage around the pipe?

[LCHIEN]

I read that they intended to drill a new well to intersect this one near the oil resevoir. This new well would pump mud and concrete to seal the well, similar to the top kill but pumped from the bottom instead of the top.

If the cement around the well pipe is questionable, will sealing the pipe from the bottom cause the same risk of leakage around the pipe?

Actually they're drilling two wells. One and a spare in case anything goes wrong.

If they intersect the old drill bore just above the reservoir, then they can pump heavy mud at full bottom hole pressure without breaking down the old bore. The mud and later cement will be heavy enough to hold back the oil and not break down the old drill bore since it will be in the new bore and applying hydrostatic head to the reservoir. Once the cement cures then it will be sealed in.