Update on BP's top kill efforts, now largest spill in US History

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

It should, for the ocean is infinitely more valuable to life than oil and its products. But I'm not holding my breath. . .

Try explaining that to the heavily subsidized farmer in land-locked Nebraska who wants to know why he should pay more for his farm implement diesel fuel, more for his natural gas sourced ammonia fertilsers, more for his petroleum chemical based herbicides and pesticides, and more to the energy consuming handlers and transporters that he uses to get his crop to market.

[KGW]

Re: Update on BP's top kill efforts, now largest spill in US History

It should, for the ocean is infinitely more valuable to life than oil and its products. But I'm not holding my breath. . .

Chernobyl didn't stop the world from continuing to build nuclear reactors. The Macondo blowout won't stop the world, including BP, from drilling deepwater offshore wells.

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

I'm beginning to doubt BP will ever get another chance to drill a well in waters this deep. So we may never know what changing any "drilling procedures" would accomplish. Sounds like maybe the "relief well by August" is being very optimistic. What happens if that does not work? How long will this thing gush? Years? Decades?

I would be happy to take the other side of that bet. I don't have any difficulty imagining there will be more deepwater rigs drilling for oil in the Gulf of Mexico five years from now than there were just before the Deepwater Horizon ignited. As the cheap supply of oil depletes it has become a difficult and dangerous job to find more of the stuff. The citizens of the USA may finally be starting to understand that...some day maybe their politicians will catch up with them.

The current ban on drilling in the Gulf of Mexico makes some sense because there are simply not enough resources in the industry and the government agencies to deal with a second simultaneous serious offshore incident at the moment. But a complete and permanent ban on drilling in the basin that supplies 10% of USA daily consumption of both crude oil and natural gas would be another matter entirely. I do not see that happening.

As for how long it keeps flowing, the relief well is the best shot and will be tried more than once if necessary. Also, the collapsed marine riser is attached to a high pressure fitting on the top of the wellhead/BOP stack, so removing the riser [either cutting it off, or using the remote underwater robot vehicles to unbolt the flange] and positioning a second BOP or new riser manifold connection is still an option. The reason this hasn't yet been attempted is because the current thinking is the riser is acting as a choke and limiting the flow to a large degree, and therefore removing it will likely increase the flow measurably...which means if they are subsequently unable to position the BOP or new marine riser they will have a bigger problem on their hands. As I said...difficult and dangerous.

More like Chernobyl if this continues. But I really don't see what Obama has to do with it. I doubt any human effort could contain a spill of this magnitude. And I have not heard any evidence that his administration was regulating drilling any differently than previous ones.

Chernobyl didn't stop the world from continuing to build nuclear reactors. The Macondo blowout won't stop the world, including BP, from drilling deepwater offshore wells.

[metalman]

Re: Update on BP's top kill efforts, now largest spill in US History

thank you. facts... how refreshing.

[flintlock]

Re: Update on BP's top kill efforts, now largest spill in US History

More like Chernobyl if this continues. But I really don't see what Obama has to do with it. I doubt any human effort could contain a spill of this magnitude. And I have not heard any evidence that his administration was regulating drilling any differently than previous ones.

[D-Mack]

Re: Update on BP's top kill efforts, now largest spill in US History

Obama's Katrina or Three Mile Island or both?

President Obama says Gulf Disaster "Should Serve as a Wake-up Call that it’s Time to Move Forward" on Energy and Climate Bill

[flintlock]

Re: Update on BP's top kill efforts, now largest spill in US History

I'm beginning to doubt BP will ever get another chance to drill a well in waters this deep. So we may never know what changing any "drilling procedures" would accomplish. Sounds like maybe the "relief well by August" is being very optimistic. What happens if that does not work? How long will this thing gush? Years? Decades?

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

So, that article about the Schlumberger engineers bailing out just before the explosion was bogus?

I am at the point where I don't believe much of anything I read about any topic in the mainstream media any more. On Macondo the noise has completely overwhelmed the signal...

[Master Shake]

Re: Update on BP's top kill efforts, now largest spill in US History

Show us the evidence that BP "skimped" on cement or anything else while setting the intermediate casing sections on the blow out well and then you might have a case for what you are implying above.

You can't, and therefore you don't.

The methods that are used to drill these wells come from the collective experience of all the operators in the Gulf of Mexico, not just BP. There's lots of accusations floating around, many of them in highly emotional and perjorative wrappings. As an engineer I couldn't give a damn what the world thinks of BP...I am only interested in what actually happened and why. That means stripping out all the emotion and politicization around this tragedy and trying to extract the facts.

Comparing how the Macondo well was drilled and cased with procedures used in the high Arctic or Norway is not nearly as relevant as comparisons with how the most experienced operators in the Gulf of Mexico are drilling similar wells through the same geology and to the same targets in the adjacent exploration blocks. And so far I have seen no compelling evidence that the way BP drilled and cased Macondo differs materially from the way Exxon or Shell or any other experienced GoM operator would have drilled and cased that same well. Let's remember that the well was completely cased and had passed the positive and negative pressure tests before the blowout. It is the sequence of events that happened after that allowed the blowout to occur.

So, that article about the Schlumberger engineers bailing out just before the explosion was bogus?

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

GRG55, what is the incremental cost of drilling a relief well along with the main well, when examined in the context of an entire project like this? Does it raise the cost of the oil extracted by one percent, or by 50% or double it? Since a relief well is apparently the only truly effective remedy for a blow-out under sea, how much do we raise the price of a barrel of oil if we ALWAYS install them to be ready for the rare event when we actually use them? Thanks again for your amazing technical insights here.

I'll come back to an analogy I used before. This blowout is something like having all the engines on a B747 fail in quick succession. We can safely surmise that something failed at the bottom of this fully cased well to allow formation oil and gas to enter the wellbore. That is like having the first engine fail on the airplane. Rare, but it should not be catastrophic. What turned this into a blowout is a sequence of subsequent events culminating in the failure of the last line of defense, the blowout preventors. That was like losing the last engine on the plane. At that point you know you can't keep it in the air and you are going down.

It all comes down to a matter of risk management. We could build even more redundancy into our commercial aircraft fleet and therefore try to further reduce the fatal accident rate - and we do try to make changes from what is learned from each and every air crash investigation. The same thing will happen after the investigations into the Macondo blowout are completed. Drilling a simultaneous "relief well" may not be the answer [is six engines better than four?], we'll just have to wait and see as the real facts come out as to what actually happened and why. That should be what drives changes in procedures and regulations.

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

GRG55, I suspect you know it already, but BP WILL be changing the "drilling procedures" a LOT so as to over design this well for safety and not skimp on using "too much" cement when cementing the different sections of the completion ;)

Show us the evidence that BP "skimped" on cement or anything else while setting the intermediate casing sections on the blow out well and then you might have a case for what you are implying above.

You can't, and therefore you don't.

The methods that are used to drill these wells come from the collective experience of all the operators in the Gulf of Mexico, not just BP. There's lots of accusations floating around, many of them in highly emotional and perjorative wrappings. As an engineer I couldn't give a damn what the world thinks of BP...I am only interested in what actually happened and why. That means stripping out all the emotion and politicization around this tragedy and trying to extract the facts.

Comparing how the Macondo well was drilled and cased with procedures used in the high Arctic or Norway is not nearly as relevant as comparisons with how the most experienced operators in the Gulf of Mexico are drilling similar wells through the same geology and to the same targets in the adjacent exploration blocks. And so far I have seen no compelling evidence that the way BP drilled and cased Macondo differs materially from the way Exxon or Shell or any other experienced GoM operator would have drilled and cased that same well. Let's remember that the well was completely cased and had passed the positive and negative pressure tests before the blowout. It is the sequence of events that happened after that allowed the blowout to occur.

[Shakespear]

Re: Update on BP's top kill efforts, now largest spill in US History

As the relief well is drilled the crew will have to carry out substantially the same procedures as during the drilling of the original well...for example setting and cementing intermediate steel casing at intervals on the way down. Until they get near the intercept point there normally won't be any significant differences in the drilling procedures.

GRG55, I suspect you know it already, but BP WILL be changing the "drilling procedures" a LOT so as to over design this well for safety and not skimp on using "too much" cement when cementing the different sections of the completion ;)

[Andreuccio]

Re: Update on BP's top kill efforts, now largest spill in US History

The third of the oceans part is Revelations. I think the "Wars and rumors of wars" is from Matthew.

[ThePythonicCow]

Re: Update on BP's top kill efforts, now largest spill in US History

Thanks for the update, GRG55. It makes sense (dang -- I don't get to use the phrase "clear as mud" ;).)

[GRG55]

Re: Update on BP's top kill efforts, now largest spill in US History

...How does the releif well work? I assume it lowers the pressure in the resevior and the hole in ground will stop spewing oil.
How close to the actual well do they have to get to lower the pressure? How sure of a thing is this?

"Relief well" is actually a bit of a confusing misnomer. A relief well is not designed to "relieve pressure" from the existing blowout wellbore. Quite the opposite actually.

A relief well is drilled in a similar way to a conventional well but it targets to intercept the blowout wellbore above the producing formation [using directional drilling techniques]. In this case the blowout well is roughly 15,000 feet deep [measured from the wellhead on the ocean floor] so the relief well will be targetted to intercept at perhaps 8,000 - 10,000 feet sub-seafloor depth. As the relief well is drilled the crew will have to carry out substantially the same procedures as during the drilling of the original well...for example setting and cementing intermediate steel casing at intervals on the way down. Until they get near the intercept point there normally won't be any significant differences in the drilling procedures.

A little dissertation on drilling mud might be worthwhile here. The "mud" isn't a mixture of soil and water like the stuff we played with in the back yard as kids. It's actually a complex chemical soup that has a specific gravity greater than one [e.g. it is denser than fresh water] that can be controlled by changing the chemical mixture and water content. It serves several purposes. In addition to holding back the formation pressure as the well is being drilled the drilling mud also cools and lubricates the drill bit, and picks up and holds the rock cuttings from the bit in suspension to carry them back to the surface during drilling operations [the drill cuttings have to continuously be removed from the well or the bit risks being jammed in the bore]. The higher the density of drilling mud the greater the margin of safety over formation pressure but also the greater the viscosity. The greater the viscosity the slower the rate of drilling [think of it as turning the long drill string and bit in a thicker "sludge"]. This is one dilemma facing BP now - do something quick dammit, but make sure you don't have another screw up.

For this reason normal mud weights will be used to drill most of the depth of the relief well [contrary to some reports BP really would like this nightmare to end sooner rather than later]. I do not know the details of BP's relief well drilling program, but typically a relief well is not drilled all the way into the blowout wellbore. As it approaches the intercept point, but before actually hitting that target, drilling is often suspended and the relief wellbore is circulated to the "kill fluid", which in this case is likely to be a "weighted up" mud [sometimes in shallow, lower pressure wells, salt water alone is enough to kill the well]. The combination of the hydrostatic head from the heavy kill fluid and hydraulic pressure applied to the relief wellbore from surface is used to fracture the rock creating a pathway from the end of the relief well to the blowout wellbore, through which the kill fluid is forced at high rate in an effort to overcome the blowout formation. This is seriously complicated by the fact that the original wellbore is cased and cemented all the way down...so they may have to use shaped explosive charges to make the connection from the relief well to the blowout bore.

A relief well is the only reasonably high-probability-of-success way to kill a blowout like this one. That is the reason that starting the first relief well was done as quickly as possible by BP. So reliant are they on the success of this technique that for back-up a second relief well is drilling about one week behind the first one...just in case something goes wrong with the first relief well [stuck drill bit, hole collapse, etc.]. They simply cannot afford to wait to start a second relief well until after they have any sort of problem with the first one. If the first attempt with a relief well fails, then there will be a second attempt, and if necessary a third and a fourth...because there is no other better option to stop the blowout.

Hopefully the above description is reasonably clear...if not let me know and I'll try again [for you drilling engineers out there, I know I have had to make some simplifications in the interests of clarity].

Finally, for those who still think that blowing up the well or dropping something big on the wellhead is a good idea, I would suggest you reconsider. No engineer in his right mind would ever do anything to deliberately risk the integrity of the wellhead. If explosives are used to try to collapse the well casing and pinch it off and it destroys the wellhead in the process, then the ability to actually secure the well is seriously, seriously compromised. I would not be willing to depend on a pinched off casing to contain the well forever. If such an attempt failed to pinch off the well then the risk is an absolute open flow blowout...and if you think they have problems now... ;-)

In Kuwait after Gulf War I, many of the wellheads had been sabotaged by Saddam's retreating troops. Before many of those wells could be secured the damaged wellheads had to be cut off, new casing bowls secured to the casing stubs and new wellheads installed...all while the wells were spewing flammable hydrocarbons immediately above the workers. Try that in 5000 feet of water.