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  • #16
    Jerry. that wasnt wax, it was methane hydrate, a sort of ice-like material that floated to the top of the container, making it buoyant. It will happen every time they try that approach.
    We engineers tend to try and be a bit God-like at times, and usually it comes around and bites us on the a$$, and if we are VERY lucky, only a few people get hurt. You can bet that NOBODY actually ran through a worste-case scenario involving a failed BOP at that depth, or if they did, all records were burned. BP if you recall, had an embarrassing leak/spill on their section of the Aleaska pipeline a couple of years ago. It turned out that they had deliberately "forgone" preventative corrosion inspection/maintenance on the line even though they knew that the oil was sour and corrosive.
    We up here are just commencing our deepest offshore well. Chevron is drilling in 4 kilometers of water and the politicians are saying "the economic benefits make it essential to the economy of Newfoundland and Labrador." I wonder what the quote will be if THAT one blows out? Worse yet, we just granted offshore drilling licences, (four,) to BP to drill in the Beaufort Sea. I wonder how THEY will go?
    NOBODY has the technology and/or skill to carry out effective manipulation of heavy equipment under the conditions that exist at that wellhead.
    I truly hope that I am proven wrong, but I think that that well is going to leak a LONG time. Duffy
    Duffy, Gatineau, Quebec

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    • #17
      Nuke'd Well

      http://www.youtube.com/watch?v=CpPNQoTlacU

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      • #18
        Originally posted by Duffy
        I truly hope that I am proven wrong, but I think that that well is going to leak a LONG time. Duffy
        Here's hoping the relief well can pump enough goop in there to slow it down enough cement will work.
        Design to 0.0001", measure to 1/32", cut with an axe, grind to fit

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        • #19
          Originally posted by Duffy
          I think that that well is going to leak a LONG time. Duffy
          A small tactical nuke is starting to look pretty benign compared to this thing leaking for gawd knows how long.

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          • #20
            Uh,guys there is a gawd awful amount of methane gas in that seabed along with methylhydrates,setting off a nuke might seal the well,but would probably also release a cloud of methane the likes of which we have never seen.
            I just need one more tool,just one!

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            • #21
              Originally posted by camdigger
              Some relatively random inlargely incoherent ramblings.

              Down hole pressures are always startling, but I was under the impression they were using 16 ppg mud to get adequate hydrostatic to maintain control during the operations. At 5000' to the sea bed and another 13000' - 15000' below the seabed, the pressures mount up quick, but not 40,000 psi.
              It was one of the rig survivors who made the claim so I'll respectfully go with that until it's authoritatively debunked. The pressure in the downhole is clearly not a simple pressure gradient - there's well head pressure (from seafloor overburden above the pool and perhaps geologic folding, I presume) in addition to the gradient one expects as one goes deeper in a fluid. If it were a simple gradient there would be no flow from the well for the same reason water on the sea floor is not squeezed by the pressure toward the surface.

              From the Mark Levin show interview:

              "James: Mother Nature every now and then kicks up. The pressures that we're dealing with out there, drilling deeper, deeper water, deeper overall volume of the whole vessel itself, you’re dealing with 30 to 40 thousand pounds per square inch range -- serious pressures."

              I presume those numbers, right or wrong, represent static pressures. Once a column of petroleum, water, mud, gas, what ever, starts to move there is hydroshock when it comes up against a restriction. The gas is expanding on the way to the surface, so the length of the bubble is growing inside the header - that means the top of the bubble is moving faster than the bottom which is likely also accelerating, and the top of the bubble and all above it is accelerating even faster. Once the liquid is blown out the bubble's bottom accelerates as there is less restriction owing to viscosity. There's tremendous friction inside the plumbing, and abrasives in the stream are ripping the snot out of everything.

              Had the header not kinked over and slowed the flow I suspect it would be worn through by now or soon - that may still happen. Then you have the least possible restriction to outflow.

              I recall watching the Baldwin Hills dam in Los Angeles come apart when it developed a leak. Not a lot of head pressure but the earthen dam went from a trickle to a rupture and catastrophic failure in very little time.

              Obviously I'm no expert and didn't even get a good night's sleep, but there is a lot of info out there to follow - some is pure bs, of course.

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              • #22
                Originally posted by dp
                It was one of the rig survivors who made the claim so I'll respectfully go with that until it's authoritatively debunked. The pressure in the downhole is clearly not a simple pressure gradient .
                When you're talking "control densities", it is as simple as a hydrostatic pressure.

                Originally posted by dp
                there's well head pressure (from seafloor overburden above the pool and perhaps geologic folding, I presume) in addition to the gradient one expects as one goes deeper in a fluid. If it were a simple gradient there would be no flow from the well for the same reason water on the sea floor is not squeezed by the pressure toward the surface..
                There are a number of semantic errors here.... Control densities are sufficient to overbalance the bottom hole pressures in conventional drilling. There is no evidence that they were drilling underbalanced with pressure at surface. Had they been drilling underbalanced, the pressure at surface added to the hydrostatic add up to the effective bottom hole pressure. Tectonic action increases formation pressure which we balance with hydrostatic and surface pressures for control.

                Originally posted by dp
                From the Mark Levin show interview:

                "James: Mother Nature every now and then kicks up. The pressures that we're dealing with out there, drilling deeper, deeper water, deeper overall volume of the whole vessel itself, you’re dealing with 30 to 40 thousand pounds per square inch range -- serious pressures."

                I presume those numbers, right or wrong, represent static pressures. Once a column of petroleum, water, mud, gas, what ever, starts to move there is hydroshock when it comes up against a restriction. The gas is expanding on the way to the surface, so the length of the bubble is growing inside the header - that means the top of the bubble is moving faster than the bottom which is likely also accelerating, and the top of the bubble and all above it is accelerating even faster. Once the liquid is blown out the bubble's bottom accelerates as there is less restriction owing to viscosity. There's tremendous friction inside the plumbing, and abrasives in the stream are ripping the snot out of everything...
                Had the header not kinked over and slowed the flow I suspect it would be worn through by now or soon - that may still happen. Then you have the least possible restriction to outflow.
                Erosion is one issue. A bigger issue can be SCC from H2S. I haven't heard whether there is any H2S in the effluent or not. Hopefully, the reservoir is either a well cemented sand or a carbonate which will produce little abrasive matter, otherwise erosion can be a huge issue. Gas flows from wells can reach supersnic speeds and any particulates are very abrasive especially in bends. I've seen well test piping erode enough to leak in a mtter of tens of minutes when flowing wells to clean up.

                FWIW, it is amazing how many personnel around a rig do not understand well control and formation pressures. I'd speculate that less than 25% of the personnel on board have a good understanding of these principles. I do not have definitive proof, but I am forced to sit through a well control course every two years with some of these guys and some of the questions asked make me wonder.
                What credentials did our caller have? Was he a cook or bed maker or laborer? Due to the impending legal battle, you can almost bet he was a ways down the totem pole as all the higher ups will find themselves in discovery proceedings and possibly court as defendants or collateral witnesses.

                Originally posted by dp
                Obviously I'm no expert and didn't even get a good night's sleep, but there is a lot of info out there to follow - some is pure bs, of course.
                I am no expert on offshore operations either. I've spent 99% of my 25 year drilling and completions career onshore, but well control is still well control just different procedures and considerations.
                Last edited by camdigger; 05-11-2010, 02:17 AM.
                Design to 0.0001", measure to 1/32", cut with an axe, grind to fit

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                • #23
                  I worked on quite a few rigs in southern California from Huntington Beach to Santa Barbara (electronics vendor) and have been up and down the crane basket from the water taxi to the drilling deck and back dozens of times. I actually enjoyed that . A lot of my time was spent waiting for the water taxi to come pick me up so I would shoot the sh|t with the crew. Everyone had a passing interest in the hole and the geology, and everyone was preoccupied with safety. I got drilled (pardon the pun) on safety every time I boarded a rig. So even the galley slaves were up on the work even if not expert. The on-board scientists I normally worked with were mischievous in the extreme and probably bored to death and probably exaggerated the most. I was primarily interested in the biology found in the bore. Particularly the microsamples.

                  I even spent a lot of time on the Glomar Explorer when it was stationed in Oxnard. They had a fantastic electronics bay. I guess my point is everyone had some level of accurate knowledge, and some had a bit of pride and could recite whole reams of statistics about well depth, drill rate, tons of iron in the hole, and more. When you're out there on the rig 24/7 you have to do something with your off-duty time or go nuts.

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                  • #24
                    Originally posted by camdigger
                    When you're talking "control densities", it is as simple as a hydrostatic pressure.
                    So one thing I'd read was the curing heat from the concrete gassified or heated some hydrates. If that's the case then extreme expansion is the expected result. My understanding is they dropped the first plug in the hole and were pouring concrete when the well pharted and the rest is history. I can see how melting hydrates can over-pressurize the region briefly and push gas around up, and through the wet concrete. When that happens all the control density balances go out of balance as the gas bubble evacuates the header.

                    I guess too there are some pipe segments that cannot be cut through by the BOP even if it had tried - and the relatively low flow rate suggests the deadman control may have initiated an attempt.

                    One other thing that may be a factor and that regards the geography. That area is in the debris/fracture zone of the Chicxulub crater (the dinosaur killer meteor) and there is quite a bit of unnatural folding and sedimentation. Dunno what that might add to the mixture but it does make that area unique.
                    Last edited by dp; 05-11-2010, 03:26 AM.

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                    • #25
                      Originally posted by wierdscience

                      Some people here are also quietly wondering if it was an accident.It's odd that within 2-3 weeks of new leases being opened up and a public announcement by the prez that we have the first major spill in a very long time in the gulf.
                      Thats a good idea, start another dumb conspiracy theory, you can then blame Muslims, Jews, Black Panthers, Communists, Anti Abortionist or anyone else you happen to be paranoid about this week.

                      While everyone argues which group to blame, the real culprits can then slip under the radar.

                      Not that I'm a cynic you understand.
                      John

                      I used to be indecisive. Now I'm not so sure , but I'm not a complete idiot - some bits are still missing

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                      • #26
                        First off an admission I have no experience of these things to comment wisely but something has been nagging at me since this started.

                        I few years ago I had to go to Weatherfords in Aberdeen, these are the handy hire people of the oil rig world. I went to repair a band saw that cuts riser pipes off when they leave a drill site

                        I got a site tour whilst I was there and the bit that sticks in my mind was a deep pit big enough to drop a small house in - no joke.
                        I asked what it was for and told it was for testing the shut off valves on the sea bed, they pointed one out and it was a steel casting about the size of my van with a spring at the side of it with square coils about 8" square and as tall as the valve.

                        I was told this spring went inside the valve and held it shut, hydraulic pressure from the surface held it open so in the event of an accident it snapped shut.

                        Apparently the pit was there because a few years previously whilst testing one on the shop floor due to a flaw in the casting it exploded, one large chunk hit the end of the travelling crane halfway down the shop and spun it off it's tracks to land in the centre gangway.
                        Fortunately no one was hurt even though it was a fully staffed working day.

                        I have seen no mention of this type of valve in the reports I have read.
                        Does the North sea industry use different valves ?
                        .

                        Sir John , Earl of Bligeport & Sudspumpwater. MBE [ Motor Bike Engineer ] Nottingham England.



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                        • #27
                          I was sent a PDF file in an e-mail which outlines the problems and has pictures of the Horizon Drilling rig before and during the fire which might be if interest to some, how do I go about posting a PDF?

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                          • #28
                            You can't. If you have PDF creator you can choose to have it print images of the PDF instead of making a PDF file.

                            This problem is making the oil sands look positively benign environmentally. There have been quite a few comments to that effect on various news stories. If this takes several months to resolve, and it appears likely, the gulf coast will be a long time recovering. I can't even imagine what the cost will be. One thing is certain, the cost of oil will go up because of it
                            Free software for calculating bolt circles and similar: Click Here

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                            • #29
                              Originally posted by jugs
                              Thats a good idea, start another dumb conspiracy theory, you can then blame Muslims, Jews, Black Panthers, Communists, Anti Abortionist or anyone else you happen to be paranoid about this week.

                              While everyone argues which group to blame, the real culprits can then slip under the radar.

                              Not that I'm a cynic you understand.
                              I didn't start it,people who have worked those rigs for years did.Tripple redundant safteys failing it's almost unheard of.

                              Couple that with the fact that there are several groups who don't want us drilling including governments.That includes our own government who has floated the idea this morning of a new government agency to "over see"all drilling operations ,revenues and royalties"Guess that will be so there is no danger of a revenue stream going untapped four or five times.I mean it is a crisis afterall and we need not let it go to waste.

                              Nah,nothing to see here folks,move along

                              Course we all know who is to blame right? Those damn Limeys at BP!
                              Last edited by wierdscience; 05-11-2010, 09:09 AM.
                              I just need one more tool,just one!

                              Comment


                              • #30
                                Originally posted by wierdscience
                                I didn't start it,people who have worked those rigs for years did.
                                Rush worked on oil rigs?

                                Course we all know who is to blame right? Those damn Limeys at BP!
                                Only problem is, Halliburton had just finished cementing the well, and was in the process of completing the plug when it exploded:

                                Drilling Process Attracts Scrutiny in Rig Explosion
                                http://online.wsj.com/article/SB1000...564769072.html
                                Last edited by lazlo; 05-11-2010, 09:23 AM.
                                "Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did."

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