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Geigerclick
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They will also be using Methanol in the new cap.
pgardn said:And this is all having to be done by robot submersibles... Controlled by people that might be rockin and rolling on the surface. Pretty amazing. Amazingly difficult. I wonder how many of these things have run into each other or have gone out of commision. BP is not giving a lot up.
Its possible that we might not want to drill wells 1 mile deep anymore if we cannot fix them. On the other hand, this is a huge experiment that will get some answers. Just wish it all had never happened. Its like having a well on Mars.
This is an interesting simple view of all that has been tried so far...
http://www.nytimes.com/interactive/2010/05/25/us/20100525-topkill-diagram.html?ref=us
This says nothing about using heaters, just warmer seawater and methane (did they mean methanol, I thought methane was hydrating forming the crystals? more methane solves the problem?)
I believe it's because it is not practical to put enough structural strength into the riser pipe to support the loads required of any kind stop valve. The total force on any given 19" (ID) pipe cross section might be ~500 tons. I would think only the massive BOP manifold on the sea floor could handle that kind of load.russ_watters said:I'm a little surprised there doesn't exist any kind of valve that can be attached somewhere along the pipe, then having a slit cut in the pipe, then sliding a blast-gate type valve in place to stop the flow.
mheslep said:I believe it's because it is not practical to put enough structural strength into the riser pipe to support the loads required of any kind stop valve. The total force on any given 19" (ID) pipe cross section might be ~500 tons. I would think only the massive BOP manifold on the sea floor could handle that kind of load.
russ_watters said:I'm a little surprised there doesn't exist any kind of valve that can be attached somewhere along the pipe, then having a slit cut in the pipe, then sliding a blast-gate type valve in place to stop the flow.
...or...since this is a 9" pipe inside a 21" pipe, why can't you just drill a 9" hole through the two pipes and insert a 9" diameter rod/pipe into the hole?
mheslep said:I believe it's because it is not practical to put enough structural strength into the riser pipe to support the loads required of any kind stop valve. The total force on any given 19" (ID) pipe cross section might be ~500 tons. I would think only the massive BOP manifold on the sea floor could handle that kind of load.
Interesting. I'd like to know more about the procedure - would be necessarily very slow on descent, with the load maintained while new sections of riser are attached one after the other. We see cable drops in the graphics of all the heavy gear in these Deepwater Horizon repair / salvage attempts.stewartcs said:They actually deploy the BOP/LMRP stack on the end of the riser and land it on the wellhead.
With no experience in this line, tensile strength that high (700-1200 tons) sounds plausible to me for a (very stable?) riser pipe, but not the shear and compression loads that would appear if a valve was somehow inserted into the pipe and operated at this reservoir pressure - that is what I was referring to above.The LMRP/BOP stack weighs typically around 800,000-lbf. That plus the weight of the riser can be over 1,000,000-lbf depending on the depth. An analysis I performed not that long ago showed a static load of 1,400,000-lbf for a 10,000-ft riser and over 2,400,000-lbf when the dynamics were added (for a particular environment).
CS
mheslep said:Interesting. I'd like to know more about the procedure - would be necessarily very slow on descent, with the load maintained while new sections of riser are attached one after the other. We see cable drops in the graphics of all the heavy gear in these Deepwater Horizon repair / salvage attempts.
stewartcs said:They can typically run about three riser joints per hour. Each joint is either 75-ft (or 90-ft depending on riser design) in length. They are connected by a bolted flange typically. However there are other designs that can be used to increase the running rate.
Essentially they just connect new joints on top of each other until they reach the bottom. At that point they use a special joint called a landing joint to connect the stack to the wellhead. Then they unlock another special joint called a telescopic joint (TJ) to allow compensation of the vessel motions. The outer barrel of the TJ is connected to a tensioning system (either direct acting or wire-line type) to provide the necessary top tension to keep the riser stable.
There are of course more steps involved but that's the short version.
CS
Thanks! I was having difficulty in fathoming how the load (700-1200 tons) is transferred, hand-over-hand so to speak, from section to newly-added-section.stewartcs said:They can typically run about three riser joints per hour. Each joint is either 75-ft (or 90-ft depending on riser design) in length. They are connected by a bolted flange typically. However there are other designs that can be used to increase the running rate.
Essentially they just connect new joints on top of each other until they reach the bottom. S
Bernie100 said:Does anyone know what the approximate temperature of the oil as it comes up the well is?
Bernie100 said:Does anyone know what the approximate temperature of the oil as it comes up the well is?
Geigerclick said:I say this seriously, I have found your posts extremely informative, and if you would be willing I wouldn't mind the long version for the sake of geek-satiation if nothing else!
mheslep said:Thanks! I was having difficulty in fathoming how the load (700-1200 tons) is transferred, hand-over-hand so to speak, from section to newly-added-section.
stewartcs said:The other steps are mundane really - like preparing the drill floor, the moon-pool area, skidding the stack to well center, hanging the string off in the riser spider, etc. Most of those terms don't mean much to the majority of the people who read this since they are industry terms given to specific equipment or to a process.
I've just given the big picture. But if you have specific questions I'd be happy to try and answer them.
CS
Yes, I should have guessed there would be a hoist in the works somewhere. Thanks again.stewartcs said:Each joint is basically sitting in what we call a gimbaled riser spider. The spider sits over the well center on the drill floor while running or retrieving riser. The joint sits on a load shoulder in the spider and holds the entire riser string (with stack on the bottom of last joint) while the next joint is stabbed in and bolted up. The draw-works (big hoisting system) then picks up the string of riser so the spider can be opened partially and then lower down the full length of the joint that was just made up. ...
M Grandin said:I suggested this:
"POSSIBLE REMEDY TO BP OIL LEAK ? Is it not possible sinking succesively smaller (=less diameter) and smaller steel tubes inside present tube in the well? At the same time "gluing" them to surrounding tube. Resulting in a layered steel tube of smaller and smaller inner flow diameter? At last a solid steel shaft is inserted in the last most narrow cylinder. Never a very huge force would be needed to press these units into the remaining cylindrical hole. At least every new cylinder inserted into the wider outside, will decrease the flow - so at last hardly no oil is leaking through. Theoretically this must work. Perhaps also possible inserting a large number of steel bars successevely into the main tube according to the same principle. But the point using cylinders might be possibility minimizing dead space allowing oil leaking through. Just a layman suggestion, almost certainly already considered - but I guess all suggestions are interesting in this critical case. (This is a copy of what I wrote in an ATS thread - perhaps already suggested here) "
Arizona said:What about series of detonations? This could be a quick fix until the relief well is drilled. Detonations can be performed in a matter of weeks. I hope they are not trying alternative methods for the sake of reusing the well bore or to continue to collect oil. They need to stop the oil ASAP.
Drill many small diameter holes lined with explosive ~1000 meters around the well bore. Use the series of detonations to implode the well hole and cover it with ruble (i.e. make the Pressure inside the well<Pressure outside the well). I almost feel that the extreme pressures of the environment would allow for more controlled explosions or implosion from the detonations. This could stop or slow the leak until the relief well is completed.
I did some rough calcs and oil pressure at ~5000 psi, one would have to implode and cover it with ~1000 meters of ruble. I wonder how many meters they can drill in a day?
I have not heard of ideas regarding detonations of the subsea architecture or an implosion of the well head. What are the risks besides letting the oil leak like it has been for the last month? I am sure the have the well bore mapped.
BP should release some stats on the problem (i.e. map/diagram of the well, P's, T's, and V's, effluent components, flow rates, surrounding material properties, etc.) so some independent engineers can be more serviceable
Geigerclick said:I have no experience with modern ROVs, but isn't this incredibly delicate work to be doing with remote feeds and ROVs? It sounds as though they could damage the riser relatively easily.
stewartcs said:The riser is already damage and has no pressure containing capabilities so it doesn't really matter if they damage it more.
CS
No pressure containment? The riser appears to be kinked or otherwise has its ID reduced, possibly by internal debris. These conditions would reduce flow (and increase pressure inside the riser) as compared to a cleanly square cut riser head atop the BOP. I assumed this was the reason spill flow is expected to increase by 20% (per reports) after the cut, prior to a re-containment of some kind.stewartcs said:The riser is already damage and has no pressure containing capabilities so it doesn't really matter if they damage it more.
mheslep said:No pressure containment? The riser appears to be kinked or otherwise has its ID reduced, possibly by internal debris. These conditions would reduce flow (and increase pressure inside the riser) as compared to a cleanly square cut riser head atop the BOP. I assumed this was the reason spill flow is expected to increase by 20% (per reports) after the cut, prior to a re-containment of some kind.
Yes I understand the riser won't hold reservoir pressure. The point was that slicing off the riser is likely to increase the flow temporarily, as the current damaged riser is partially restricting it.stewartcs said:No pressure containment by design. Strictly speaking, it does offer some pressure containment but that's just a consequence of the the required collapse resistance of the pipe. But it is not designed to contain well bore pressure (other than about 500-psi).
zoom_in said:This type of problem highlights both the shortcomings in our (namely the internet's) ability to vertically integrate information streams and the enormous potential of such integration.
Over six billion minds on the planet, millions of people in the US alone with degrees in the sciences and engineering--all of it an underutilized resource on problems such as this one.
I know the BP engineers are working hard to create solutions but regardless of their intelligence or number, they cannot match the potential power of a vertically integrated open approach in a public medium. What do we do when the next disaster like this happens? Do we commit to blind faith in the ethereal "experts", possibly leaving the solution to a handful of stressed-out, overworked engineers or do we demand "information transparency" where any and all technical details (by law) must be made readily available to the public? I have browsed this thread and seen the posts of people who have searched in vain for various tech specs. This is not a BP problem any longer, it is a national problem and a national resource is being wasted--namely the potential power of millions of minds gathered to assimilate raw information streams and produce solutions.
If we want to choose a best solution, why not make the pool of candidates as large as possible? Better, why not generate multiple, overlapping solutions? How many millions does this leak cost daily? For example, a fabric funnel (if it's an efffective idea) could be built concurrently with the ongoing efforts, as a back-up, as insurance, or even to capture the excess that leaks out around the LMRP cap.
I spent about two hours wading through advertisements, waiting for pages to load, downloading relevant diagrams (BP had a FIVE Mb picture file from its failed junk shot attempt with nowhere near that much information in it), sifting through lists of ideas with huge amounts of repetition and no vertical integration, all to produce my ~uneducated guess (partly thanks to no tech specs, at least not without spending another several hours hunting them down and getting hit-or-miss results) as to why various ideas didn't work, to post it in a likely unseen spot in the comments section on a blog on a PBS website.
Take one percent of the energy involved in the finger-pointing, the blame-laying, and the sound and fury about this leak in the media streams--take that one percent and devote it to information transparency, a central website with forums and hierarchical moderation, and focus the above-mentioned national, even global, resource on solutions.