Not Impressed with BP's Top Cap Procedure

[erpowers]

Since BP has placed the cap on the oil well I have not been impressed with what has happened. I realize that it was pointed out that as a result of the attempt to cap the well there was a chance that there would be more oil released into the gulf. However, it seems that things have gotten worse without anything getting better. From the pictures that that I am seeing on tv even with the cap on there is much more oil leaking into the gulf than before.

[BeFree]

1. Thank god for dispersants!!

If all that oil just went to the surface then all the beaches would have oil on them.

BP has saved the beaches!! Good job, BP!!

:puke:

[Schema Thing]

2. er, no.

[damntexdem]

3. Oh, but you should be: it doesn't stop the gusher, but it recovers oil.

So the gusher still pollutes, but BP gets oil on which it can make a profit.

So much better than plugging the gusher -- then they wouldn't be able to recover anything until the relief well is finished, if it works.

[pipoman]

4. Plug it already

[tiptoe]

5. Nor is Dimitry @TheOilDrum Mmbr 1wk4dy ('apparently you don't work on Star Wars'..."Well, I do...")

http://www.theoildrum.com/user/Dimitry/comments

http://www.theoildrum.com/node/6558#comment-640208 Dimitry on June 4, 2010 - 12:59pm

One more time.

The current approach being tried has simply not seen any calculations and is driven by non-technical considerations. This is largely another "siphoning" time waster they tried before. Sure they will bring a trickle to the surface (like 10% of the flow) and will get headlines that say "all on track". 90% of the stuff is going into the Gulf.

Do the math. Draw a control volume around the cap. Look at the inlet and outlet pressures.

The inlet pressure will vary between the stagnation pressure inside the BOP (~3 ksi) and if you temporarily assume a good seal to the top flange, stagnation pressure of the reservoir (~13 ksi). The oulet pressure is about 2 ksi, if the entire upper tube volume is filled with oil. On the other side of the seal is 2.2 ksi water pressure.

Now look at the seal. Can it stand up to 3-11 ksi pressure differential? N.O. It's going to leak like a sieve, with an alternative outlet area larger than the area of the tiny pipe they cleverly fitted on this engineering marvel. So where is majority of the flow going to go? Right out into the water. "The chimney effect"? Sure, consider the tiny pipe evacuated entirely - pure vacuum, 0 psi. The seal will still leak like a sieve, it can't hold any significant pressure differential.

This is just a dumb static calculation. If you add the complexity of viscous, multi-phase flow that is really coming out of the BOP, very little of it will be channeled into the tiny pipe over the terribly inefficient blob of the manifold. They didn't even try to reduce the diameter over a large length! Remember, flow has momentum, viscosity and turbulence, it takes a lot of work to take it from one geometric form factor and "fit" it into a smaller space - you have to do work and in order to do that you must be able to contain manifold pressure. This is so basic, any engineer who really works with this stuff should be able to do this in his or her sleep.

I am now conviced that BP is not running this with engineering first, but rather as a PR excercise with managers in charge who really do not know the core business of their company.

The only way they can deliver this devil of a flow to the surface is in a 21" riser pipe - exactly as they do in production.

http://www.theoildrum.com/node/6566#comment-641970 Dimitry on June 5, 2010 - 10:26pm

I understand their system for getting some oil out to the surface in the safest possible way to their topside crew.

It does get some oil out of the water and gives them at least some good press.

I also think it is not the best approach for the nation.

BP methods have been very cautious from the beginning. While I understand their motives, I think that the leak site should have been nationalized, their license revoked and another company, perhaps not an oil company brought in to deal with the leak. All of these things are controlled by political, not technical decisions.

The topside risk should be weighed against the massive pollution risk and a national disaster which is unfolding.

Leaving things in a legal status quo has been a mistake as evidenced by the gigantic amount of oil that has leaked into our waters so far.

http://www.theoildrum.com/node/6566#comment-642085 Dimitry on June 6, 2010 - 12:32am

...
If you continue to argue corporate liability, this thing is going to liably go on for a very long time to come.

Someday you just got to get out of the "business as usual" paradigm. I argue this time is now.

http://www.theoildrum.com/node/6566#comment-642068 Dimitry on June 6, 2010 - 12:22am

My point is status quo is unsustainable here.

If there is a company who can get the job done, but needs to have liability limited, that can be done.

I am a professional in my own field and I don take responsibility for my decisions, and had done so for nearly 25 years.

In my line of work - military missiles, large naval radars - three failures in a row is not an option. If that is the result, in many fields it means you are done for now, lets bring in another team.

I am sorry if the BP engineers and managers feel hurt and under appreciated. Frankly, they are big boys and girls and they will get over it. Their individuals feelings is really not the most important thing here, nor is the BP corporate survival.

http://www.theoildrum.com/node/6566#comment-642124 ormondotvos on June 6, 2010 - 1:25am

"In my line of work - military missiles, large naval radars - three failures in a row is not an option."

Apparently you don't work on Star Wars.

I think the arguments for BP continuing are sound.

Mere frustration isn't evidence.

http://www.theoildrum.com/node/6566#comment-642132 Dimitry on June 6, 2010 - 1:31am

=Apparently you don't work on Star Wars==

Well, I do, though we don't really call that anymore :)

Did hit that satellite recently, one shot.

Not too shabby for a "way out", "never done before" kind of thing.

http://www.theoildrum.com/node/6568/643108 Dimitry Jun 7 2010 - 1:20am

I really don't understand why you are so upset at another engineer, who is looking at billowing oil entering our Gulf trying to suggest a better alternative.

I can sing praises to the great feats of BP engineering, who welded a simple cap out of steel, placed it on a roughly cut riser pipe and have achieved less than 50% collection after 40 days of trying. I know it was difficult to do at this depth and I know the people who are doing are very good at their job. From an engineering point of view, though, it is a very crude and rough concept prototype, with no refinement and very little analysis.

I proposed a simple system, that has less back pressure on the BOP, uses standard production equipment and very standard flow management (hydraulic valve, diverter), allows for 100% oil capture to topside or refinery pipe and allows the industry to do what it does best - to produce oil, instead of producing CFD analyses.

What's more it is far cheaper than the schemes tried so far. All standard equipment except for a hydraulic valve and diverter, and I know the oil industry can make that.

And judging by their practice on the flange bolts right now, that's exactly what they are finally thinking, too.

Are you upset that a lowly "cookbook" aerospace engineer has thought of this rather obvious solution?

http://www.theoildrum.com/node/6568/643130 Dimitry on June 7, 2010 - 1:49am

...
What I am proposing simply has a wide open 21" diameter riser full of oil to the surface or another low pressure sink. It will have lowest pressure on the BOP, unless the production equipment applies it. Since we wouldn't want that, if the flow is too much topside, a simple hydraulic valve/diverter will put the flow into the water, instead of the main stack. Depending where the splitter is, a full divert can bring the the pressure on the BOP to the full water pressure (which it had before the cap), or slightly less, if it is closer to the surface.