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July 28, 2010

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Thanks for this, Jacob. Very nice job!

I am a mechanical engineer, but I have mostly designed and built machines smaller than a car, and the most difficult environment I've worked on them in was a semiconductor cleanroom. So I'm a complete layman on deep-sea oil drilling. Still, I have to say a few things. (As opposed to "I have a few things to say", please note.)

First, a couple of months to design, fabricate, and install ANYTHING is pretty quick turn-around. Especially if it's a retrofit, weighs many tons, handles thousands of psi, and has to be installed in mile-deep water by robots. Even more especially if there's any corporate bureaucracy in the way. I could tell you stories about purchasing departments that would curl your hair.

Anyway, I have no doubt that junior engineers at BP were sketching a bolted stack cap on napkins in the cafeteria from the moment they saw the first underwater pictures. No guarantee they saw the pictures right away. And I can easily imagine the senior engineers, and the engineering managers, saying things like "That will take months!" and "We can't be sure it will work; we've never done it before!" and ordering the junior guys to work on the top-hat and whatever that finned contraption was.

But it's entirely possible that no, BP started the A-team working on the bolted stack cap very seriously on day one, and it just plain took 3 months because as the saying goes, "You can't make a baby in 1 month by getting 9 women pregnant". The other kill attempts were just to pass the time, in this view. The top kill, at least, was absolutely, positively just for show.

One thing is a complete mystery to me: people were concerned about the pressure building up and bursting the well inside the seabed as a result of slooowly closing off the flow. Fair enough. But then what the hell is the theory of operation of the "blowout preventer"? Isn't it designed to close off the flow rather fast? Are we maybe lucky that the BOP failed to slam shut?

A really important question to add to your list: how long will the NEXT deep-sea gusher take to kill? If it's identical to this one, maybe they can save a few weeks by dusting off the blueprints for this stack cap. But of course it won't be identical. Once again, the solution will have to be invented; once again it will be something that's never been done before.

By the way, there are 86,400 seconds in a day. Even at 90K barrels a day, we're talking about one barrel per second gushing out of that well. I certainly could not tell from the low-quality video I've seen whether 1 bbl/sec is what we were looking at, coming out of that 9" pipe. What I never saw anywhere was a wider shot: how quickly was that roaring jet spreading out into a lazy plume as it went up?

A barrel of oil, floating on water, will spread out to an enormous area if left to itself. (Interesting factoid: the first reasonably accurate measurement of the size of molecules, long before anybody was sure that atoms are real, was made by dropping a very small, measured volume oil into a large pan of still water and measuring the ultimate surface area of the slick.) Gathering up oil that has spread out into a square-mile layer a few molecules thick seems like a horribly inefficient way to collect a barrel of oil per second.

Pumping "dispersants" into the oil right as it gushes out of the broken pipe seems like a very good way to make gathering up the oil, at the surface, even harder. The point of dispersants seems to be to make oil do that which it doesn't like to do, namely mix with water. If you believe that "The solution to pollution is dilution", then maybe dispersants are a good idea -- for small spills. But not for large gushers.

What oil likes to do is float. Even oil with lots of gas in it that forms clathrates at low temps and high pressures inside rigid pipes demonstrably floats up to the surface if unconstrained. If you could get it to float more or less straight up, to a very localized area of the ocean surface, the job of collecting it would be much easier. Instead of millions of feet (hundreds of miles) of "boom", I say it would have been better to make a mile-long windsock, maybe 100 feet across at the small end and 1000 feet across at the big end. Sink the small end over the gusher; float the big end at or near the surface. The windsock's only purpose would be to keep the rising plume of oil from spreading out very much during its one-mile vertical trip. Evidently there are currents in the Gulf that would tend to drag the windsock off the vertical, but also evidently those currents are small enough that rigs like Deep Water Horizon can maintain position by actively thrusting. I bet a dozen tugboats could keep the windsock near enough to vertical.

IF such a thing could be done, you'd have a barrel of oil per second floating up into a puddle 1000 feet across. Sucking it up right there would be infinitely easier than spooning it off sandy beaches a hundred miles away. Worst case, you could burn it off. A 1000-foot diameter torch would be a hell of an inferno, but not nearly the mess we've got now.

I will end this incoherent ramble (which I lacked the time to make shorter) by asking once again: had the Dubai-based cement contractor sealed the well, had the Swiss-based drilling company not lost 11 people, had the Marshall Islands flagged drilling rig not blown up, had the British company that owns the well jointly with a Japanese company been producing instead of losing 90K barrels a day all this time, in what possible sense would it have been "domestic" oil?

--TP

And the spill lasted more than four hours because they used the cheapest, generic brand.

Someone left the cake out in the rain, and the sweet green icing is flowing down.

Jacob and Tony. Interesting and excellent.

Is it true that Errata Irksomely at Redshite caused the platform to explode and tip over by shooting it with his wife's shotgun?

My best guesses:

"Why were images of the flowing wellhead not released to the public until May 12th?"

It takes time to do this and ROV operators had better things to do; also, PR.

"Why was the obviously grossly-underestimated 1,000 barrels/day BP figure allowed to stand for even the first week (etc)"

Worth noting that flow likely increased substantially over two months; measuring surface slicks is inaccurate with a deep water well w/ dispersant applied at the source and there wasn't an established way to make an estimate.

"Why did BP not have production ships capable of processing 10,000+ barrels a day (etc)"

I don't think the problem was ever having enough ships circa June, but having the plumbing at the wellhead to get oil to the surface.

"Why did it take a month and a half after the hardly-functioning and poorly-sealing "top hat" device was attached for a securely-bolted "capping stack" to be attached?"

Because it was producing a majority of the flow and delivering dispersants to the rest. A secure cap subjects the wellhead to pressures that could be catastrophic... which is why it took several days to test it when it was installed. People were talking about totally capping the well from the beginning.

"Fair enough. But then what the hell is the theory of operation of the "blowout preventer"? Isn't it designed to close off the flow rather fast? Are we maybe lucky that the BOP failed to slam shut?"

The wellhead is designed to be shut off semipermanently once the well is drilled; Deepwater Horizon would go off to the next well and BP would probably let the thing sit unused until the price of oil was high enough to justify deep sea extraction. A wellhead full of broken pipes is not quite as capable. The problem with pressure build up wasn't that it would go up too quickly, but that it might be too high. Going up slowly allows them to reverse course if things start to look worse. To that end, the top kill wasn't worthless because (1) it might've worked and (2) it showed that the BOP could handle fairly high pressures and increased confidence that a cap would work. I think the consensus is that it did not work because of some lack of integrity further down the well.

"make a mile-long windsock"

As a physicist, I like this solution, but something's telling me that it's harder than it seems to make a mile long, thousand-foot diameter piece of fabric that's impervious to oil and at neutral buoyancy throughout its length.

The new Cristo/Jean Claude exhibition that plans to cover a river with miles of fabric is a similar venture without the issues of materials science if you want to find something on a similar scale.

Another question: Why was BP allowed to drill a mile down when they had no credible plan for dealing with a blowout?

Answer: sex, money, and blow.

Sebastian calls it "regulatory capture", I call it "crime".

The head of MMS got canned, but I'm still waiting for the perp walk for the folks who were, literally, f***ing the people they were supposed to be regulating.

I'd also ask: why was the press barred from covering certain aspects of the spill, in some places?

The problem with pressure build up wasn't that it would go up too quickly, but that it might be too high.

I don't think Tony P. was suggesting that the pressure would go up too quickly, but that the flow would be stopped too quickly, creating a pressure shock, much like a water hammer, sending the pressure up too high. The pressure would rise very quickly in that case, but the problem is still how high it would go, not how fast it would get there. The thing that would be too fast would be the change in the flow, if I'm understanding Tony P. correctly.

Blowout preventers have worked successfully many times before. In this case they were worried that the well bore (the part of the well underground, between the oil reservoir and the seabed) was broken or weakened, perhaps by a long period of unrestricted flow, and so they shut it off gradually.

TP, yeah, 3 months is not a long time, on the other hand BP was surely looking at billions of dollars per month in costs from the well flowing. So I think it'll be interesting to find out what they did and when. One problem was that BP's engineering work on this was not transparently communicated to the outside world - there were a lot of things tried that must have taken weeks of planning but were announced just a day or two before they were put into action.

The "windsock" idea was floated quite a few times but was apparently not practical. Well, lots of ideas were floated, what's interesting to me is that the one that actually resolved it was the one any naive observer would have thought of first.

The effect of the dispersants is going to be interesting. I think they might turn out to have been extremely effective in preventing as many concentrated slicks from forming as you'd expect, but that's an amateur's guess. We'll have to see how it turns out.

Wouldn't you rather the slicks were concentrated and therefore easier to clean up, though? Yes, the dispersants could help spread the oil, which would mean that it could be more easily broken down by bacteria and natural reactions without depleting all of the dissolved oxygen in the area of the leak, but how desirable that is would seem to depend on how toxic the dispersants are (apparently quite so) and how the long-chain oil molecules would break down, and what the byproducts would be. Keeping it concentrated and localized as best as possible for ease of skimming would seem to have been a better idea to me.

(CEE here, though just finished school)

CEE? Civil/Environmental?

Yeah, Civil And Environmental Engineering. I didn't specialize in oil spills or anything, though, just an undergrad.

Slart's a CEE, too - Crusty Electrical Engineer (if I remember correctly).

Jacob, I'm not sure why "unrestricted flow" through a pipe would weaken the pipe. Much more likely, I think, is that any damage to the well bore would have happened at the time of the "kick" that caused the explosion. I have no idea how the BOP is attached to whatever pipe sticks out of the sea floor, though, so maybe the riser keeling over was the likeliest cause of (possible) damage to the well bore.

I did not mean to derail the discussion with a hare-brained suggestion. My real point is that SOMEBODY has to be thinking NOW about containing the NEXT underwater gusher -- containing it in some way that doesn't require custom engineering the solution for the particular configuration of broken plumbing on THAT one. If the "windsock" approach has been evaluated by people who actually know what they're talking about, and been deemed impractical, that's good news: we know yet another thing that won't work.

But a generally-applicable oil-confinement approach is what deep-sea drillers ought to be forced to develop. Now, not when the next gusher happens.

We could make that a condition for granting them permits to poke holes in the continental shelf. But that would be yet another "government regulation", don't you know.

--TP

I wouldn't say crusty, exactly. I like to say, instead, that I've been around the block a time or two.

So: get off my LAWN!

TP: I'm not sure why "unrestricted flow" through a pipe would weaken the pipe.

Yeah, I think I misspoke and you're right, that they were worried about the damage done to the well by the blowout itself (and by the poor concreting job that was done on the well prior to the blowout).

A standard-sized flange fitting with bolts designed to be removed and replaced by ROVs at 5,000ft would seem like a good start, and then keeping a "mini-BOP" on-hand that fits that flange. That way even with a blowout preventer failure like this one, they could just bolt on the new cap and shut it off within a few days, rather than a few months.

I'd also ask: why was the press barred from covering certain aspects of the spill, in some places?

What's with the past tense?

Very good post, I neglected to say. Well done, Jacob.

My sister, I have to confess, is/was convinced that this was not a leaky oil well but was instead an asphalt volcano (google that, if you want a tap into a different kind of crazy ore) that was deliberately...um...ventilated, for reasons that I can't fathom, and am not really interested in fathoming.

So to speak.

Probably because I used asphalt volcano, we're going to wind up on Google, but sometimes it's more convenient to have the crazies deliver than to send out for crazy.

And fortunately, the crazies are more than willing to do that.

But a generally-applicable oil-confinement approach is what deep-sea drillers ought to be forced to develop. Now, not when the next gusher happens.

We could make that a condition for granting them permits to poke holes in the continental shelf. But that would be yet another "government regulation", don't you know.

Isn't this the critical question? The lack of preparation and planning strikes me as stunning.

Here's a stupid question from a non-engineer: Why couldn't, among other things, that flange have a rim with holes in it so that a new whatever could be bolted on without having to remove the old bolts? Shouldn't these things be designed, in general, to make it as easy as possible to attach various items of equipment that might be needed?

Why couldn't, among other things, that flange have a rim with holes in it so that a new whatever could be bolted on without having to remove the old bolts?

Things are not designed to be repaired easily in case of failure largely because they're designed not to fail. A rig being destroyed by fire and falling, causing the riser pipe to crimp and break; those things are outside of the design space.

It's a good question: how many designs for different failure contingencies could or should be implemented?

I'd tend to go a different route: design and have standing by repair equipment that could address catastrophic failures. Don't have the equipment to do assembly and disassembly of heavy equipment remotely, a mile underwater? Invent and build some. If the bolts were corroded so they couldn't be undone (and I don't know for sure that was the case), you need to be able to cut them off, or drill them out.

They eventually managed to remove the bolts with a hydraulic tool, although I did watch them practicing for hours and hours one day on another piece of pipe down there - it was really agonizing watching the poor ROVs trying literally hundreds of times to get a socket onto the bolt head.

Agree on the repair crew aspects, although they did have ROVs on-scene very quickly. One thing that was either good fortune or good engineering was that the riser pipe broke above the blowout preventer, rather than the blowout preventer itself breaking off and leaving the wellhead exposed where it emerges from the seabed. That would have been much harder to deal with.

Shouldn't these things be designed, in general, to make it as easy as possible to attach various items of equipment that might be needed?

Bernie, my first boss and mentor in mechanical design engineering had a rule: always throw a few extra tapped holes into any bracket you design, because someday you WILL need to field-retrofit something. So your point is well-taken.

The thing to remember, though, is that next time will be different. Next time, maybe the whole BOP will keel over, leaving a jagged pipe sticking out of the seabed. Or the well bore will fracture 100 feet underground and the oil will be gushing out AROUND the whole "sub-sea package". Or a sinking ship will sever one of the pipelines criss-crossing the Gulf like a spiderweb.

Maybe, if we're lucky, the oil will run out before the next underwater gusher happens. But if not, we need some oil-collection system that doesn't rely on ANY details of the equipment.

--TP

"1. Why were images of the flowing wellhead not released to the public until May 12th?
Why was the obviously grossly-underestimated 1,000 barrels/day BP figure allowed to stand for even the first week, and why did it take the US government a month to go from 5,000 barrels/day (April 28th) to 12,000-19,000 barrels/day (May 27th)? A precautionary approach should not have assumed "best-case" scenarios.
Why did BP not have production ships capable of processing 10,000+ barrels a day in place by the beginning of June when the possibility of "top kill" failing was well understood by then? Additional ships were not dispatched until after the "top hat" cap was in place and it was clear that the production ship on-site was incapable of processing the majority of the oil spewing.
Why did it take a month and a half after the hardly-functioning and poorly-sealing "top hat" device was attached for a securely-bolted "capping stack" to be attached? When was work on the "capping stack" started? Why was nobody talking about unbolting that flange to permanently attach a device to shut off the well from April onwards?"


To answer in order:

1. Money
2. Money
3. Money
4. Money

BP saves billions on fines by lowballing the actual flowrate. Why did the U.S. gov go along? Right now it appears Admiral Thad has not only been captured by BP, but put out to pasture.

Incidentally, we were up to 30,000-60,000 bpd before the cap.

Other questions:

- Yes, flow through the well bore could worsen the leak through sand abrasion of the casing steel pipe.

- The reason quick change flanges aren't used can be summed up in one number: 11,000 psi well pressure.

- That cap isn't going to last long. The well is only safe after it's been killed.

I don't think Bernard was suggesting that the bolts securing the flange be designed to be removed easily, but that there should be another set of bolt holes for securing capping (or other) devices that might be needed later. Tony P., M.E., seems to have gotten that.

Things are not designed to be repaired easily in case of failure largely because they're designed not to fail.

Also known as "The Titanic Syndrome".

Personally, I'm a fan of failover-in-depth.

When somebody says, "That can't happen!" I reach for my hard hat.

None of this intended as critical of slarti's comment, just an observation.

Things are not designed to be repaired easily in case of failure largely because they're designed not to fail.

The difference between things that can go wrong and things that cannot possibly go wrong is that when the things that cannot possibly go wrong go wrong they usually turn out to be impossible to repair or replace.
- Douglas Adams

"Yes, the dispersants could help spread the oil, which would mean that it could be more easily broken down by bacteria and natural reactions without depleting all of the dissolved oxygen in the area of the leak, but how desirable that is would seem to depend on how toxic the dispersants are (apparently quite so) and how the long-chain oil molecules would break down, and what the byproducts would be."

The dispersants used degrade more quickly than oil, do not bioaccumulate, and are not toxic at the concentrations they're quickly diluted to when applied a mile below the surface. On top of that, Nalco only put a dispersant into production that isn't the toxic one everybody's worried about. Although existing stocks were used early on. There's not a wealth of information out there, but there is some peer reviewed literature on dispersant effectiveness on different types of crude, toxicity, etc. Most of the research is performed by oil companies, though, so the same people who are screaming about dispersants being poison are certain it's invalid.

The traditional way of using dispersants on surface spills can be problematic near the shore... the EPA's been all over this from the get-go; go check out Lisa Jackson's press conferences months ago. Oil is toxic at high concentrations, and is highly concentrated if dispersants aren't used. Obviously everyone would prefer not to have to dump millions of barrels of chemicals into the Gulf, but it's a no-brainer in this case.

The argument that allowed BP to drill in the gulf was that The Company would act in its own best interest according to its own profit motive. They then pointed out that they have some of the best scientists, engineers and oil rig experts in world, Therefore they would be able to drill safely at depths that far exceeded any than had been attempted before. This argument proved to be false. As a country we need responsible government regulation. Companies rise and fall and their only constant function is to make as much money as they can. By design companies have no responsibility to humanity, society , loyalty or the future any more than it serves its own interest. In order for this country to prosper in the future and pay off the national dept, we need to audit our relationship with every huge cooperation and make sure those relationships are responsible and fair.

The difference between things that can go wrong and things that cannot possibly go wrong is that when the things that cannot possibly go wrong go wrong they usually turn out to be impossible to repair or replace.
- Douglas Adams

One of my favorite quotes and something I always try to keep in mind even as a software engineer. It's easy to build systems that cannot be taken apart and repaired, and tempting to do so when you believe you've eliminated the need to do so.

A very astute fellow engineer said:
"I have no doubt that junior engineers at BP were sketching a bolted stack cap on napkins in the cafeteria from the moment they saw the first underwater pictures."

Agreed.

"the senior engineers ordered the junior guys to work on the top-hat and whatever that finned contraption was."

Mmmm, I disagree, fellow engineer. In my experience, the more technical knowledge one has, the more they know the right answer. When the wrong answer is forced from above, it is ALWAYS by lexus-driving, overpaid, ignorant "power-dressing" retards who know exactly nothing about what's going on, but who apply their inapplicable daily-life heuristics to matters where they are worse than useless and override the engineers' good judgment.

If my own experience can be generalized, the backstabbing, MBA suits later blamed the very engineers who told them their cockamamie scheme wouldn't work.

Blame BP executives for this. And punish them by taking away their Lexus and their money and their suits and making THEM live in the woods... like I do.

-- faye kane, homeless brain
http://tinyurl.com/fayescave

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