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A Petroleum Engineer's Explanation

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posted on May, 31 2010 @ 12:50 AM
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While I lack the depth of experience that many here possess, I feel I do have something to contribute regarding the diesel engines running away. I am no engineer or mechanic, however, I did once discover the wrong way of Seafoaming a Mercedes diesel engine, and I feel the experience may shine some light on this.

The engine doesn't run away immediately. I believe others have mentioned that the air shutoff valves do not work right away either. After a certain amount of fuel is present in the air, it doesn't really matter if you shut off the fuel supply to the motor (ask me how I know).

Furthermore, methane is pretty light and combustable stuff. I don't know exactly how the air shutoff valves work, however, if they are RPM-actuated, I think it would be entirely possible that the engine could blow a piston straight out of the block before exceeding whatever RPM limit the air shutoff valve kicks in at. If the engine sucks in enough methane plus fuel, the resulting explosion could very easily be powerful enough to shoot a piston out before exceeding the air valves RPM limiter, or even before the valve could kick in. As far as I know, the air/fuel ratio in a diesel really doesn't matter, so "lots of fuel" = "really powerful explosion" At that point, with the air in the engine room saturated with combustable gas, anything could set it off (spark from metal on metal, hot combustion gasses suddenly being vented where they don't belong, etc...)




posted on May, 31 2010 @ 01:34 AM
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I have an idea, and here it is. I submitted on a Deepwater Response Tech form.
If you have ever seen a multi section telescoping hydraulic cylinder, then this will make sense.
In a flowing well situation, the only way to stop the flow with mud is to get the mud in the hole at a rate high enough for the mud to build a column of mud in the pipe tall enough for the difference in specific gravity to allow the mud to balance the hydraulic static pressure of the liquid trying to flow up the pipe. The problem with the recent mud attempt was that they couldn't pump the mud in fast enough, as the oil was carrying it up the hole faster than they could pump it in due to the large diameter of the hole, the oil flow rate, and the small diameter of their mud line.
My solution would be to begin dropping a series of long pipes into the well, with each length having a cone or flange near the top end to keep it from dropping completely into the well casing. By beginning with the next smaller size that would fit into the casing, and continuing with each successive pipe string being the next size down, the hole diameter (and flow rate) could be reduced in small steps. The pipes would have to be long enough down the hole so that each telescoping pipe would weigh enough be able to balance and overcome the static hydraulic force of the oil coming up.
At some point, the diameter of the bore would be reduced to a size small enough that they could pump heavy mud into the smallest pipe at a rate that would overcome the upflow. The mud would also come up between all the telescoped sections of pipe, thereby forming a column of mud and steel tall enough to finally balance the hydraulic static pressure of the oil below. At that point, cement could be pumped down the inside pipe to seal the system.
This is a rather simple explanation, and I am sure that there would be some techy things to work out, like where to get all the pipe in telescoping diameters. The materials are somewhere already. It would be just a matter of getting a drilling rig and the pipe to the site, and dropping it in the hole.

ETA, If the pipes only need to be less length than the water depth, then they could be assembled vertically using a drilling rig in the same manner that they do with casing, floated away from the rig with winch barges, then lowered into place in the hole with the oil spewing out of the pipe underwater.
Anyway, just some random thoughts.


[edit on 31-5-2010 by MelonMusketeer]



posted on May, 31 2010 @ 02:46 AM
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Originally posted by poet1b
reply to post by werk71
 


Thanks for an alternative viewpoint from someone else who works in the field.

I have to wonder if the concrete well encasing technique is adequate for deep water wells. Sounds like it can and does work, but is a tricky process.

Why would BP play so loose and fast with the rules, or technological difficulties, of drilling such wells, with so much at stake.

Who is BP? Originally they were calling themselves Anglo Arab oil.

There is some amazing information at this website.

www.modernhistoryproject.org...

Are we looking at a major play in the world's balance of power?



i only think the casing is messed up cause it was stated by BP early in this disaster on a news cast. i think their media releases are more scripted now cause this is under a microscope now.

they may have gotten away with loose practice many times that this became their standard.

can you imaging all the line(pipe) down there like a train wreck, they are lucky it doesnt obstruct the well ..

thanks for the link. gonna check it out right now.



posted on May, 31 2010 @ 03:54 AM
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Woodward Governor, while not the only people in the business, are the defacto standard for engine speed control in the industry. The UG-8 is the one that I am most familiar with. If installed on the gen sets it would have started to reduce fuel to the engine almost immediately and as the speed climbed above set point it would have eventually shut the fuel to the engine off.


Woodward governors are only for controlling fuel.
once you have another source of fuel be it crankcase oil, turbo oil. natural gas. a Woodward governor will not control a runaway.

In some cases even a intake valve will only slow down a runaway.

I had a diesel/propane mix engine runaway that would not stop even with the diesel off the intake valve closed and two CO2 fire bottles fired in the intake.
It ran for 5 more minutes on just the propane in the lines between the control valve and the engine.

Plus there was flame coming out the exhaust stack from the bad fuel air mix of crankcase oil and propane.

So much for adding propane and water injection into the intake of a diesel engine to cut the soot emissions and increase the HP.

The exhaust .er on a diesel is hot enough to light off natural gas.
heat the engine more by burning natural gas in it and every safety shutdown in the world will not stop a explosion.

[edit on 31-5-2010 by ANNED]



posted on May, 31 2010 @ 07:39 AM
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Originally posted by MelonMusketeer
By beginning with the next smaller size that would fit into the casing, and continuing with each successive pipe string being the next size down, the hole diameter (and flow rate) could be reduced in small steps. The pipes would have to be long enough down the hole so that each telescoping pipe would weigh enough be able to balance and overcome the static hydraulic force of the oil coming up.
At some point, the diameter of the bore would be reduced to a size small enough that they could pump heavy mud into the smallest pipe at a rate that would overcome the upflow.


Well the solution that will ultimately fix the problem is very similar to that, the relief wells. They are going to use those to pump mud into the bottom of the existing hole as you suggest. The problem with your idea, is how do you get pipe down the hole? Right now it's just leaking. If they open it up completely to put pipe in the hole, the outflow could make what we have now look like a trickle. Not to mention that depending on where they cut the riser, what's left may still be bent and distorted so badly I'n not sure if they can put straight rigid pipe down a bent crooked hole, if the casing got bent when the riser did. Someone else mentioned trying to insert some kind of flexible pipe in the hole but I'm not aware of 18,000 feet of such flexible pipe and it would have to withstand the pressure of the blowout pushing against it as it's lowered into the hole. Even for rigid pipe that may be a lot of pressure to overcome but a flexible pipe may just create a lot of friction on the sides and bind.

Also one thing I'm not sure about...Pipe is normally lowed into the hole by its own weight, right? If the blowout is pushing against the pipe, its weight won't be enough to lower it, what technology would they use to force the pipe down the hole against the pressure of the blowout? I've worked in normal offshore rig operations before but I've never experienced a blowout.

So there's no doubt that pumping mud in the bottom, aka a "bottom fill" is the answer to plugging the leak.

I'm sure it occurred to them to think about how they could use the existing hole to do that, instead of waiting 3 months while they drill some new holes, don't you think?

[edit on 31-5-2010 by Arbitrageur]



posted on May, 31 2010 @ 09:33 AM
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reply to post by billyjack
 


I agree with your assessment of the situation, as to the mechanics of this terrible mess. I also understand what you are suggesting be done has been done in Russia on a few of their well blow outs and worked but, all of these success were on dry land. Do not miss understand me, I am not saying that this technique can not work in the current environment that this well is in but, I think before a high risk move like that is performed which could cause shell fracturing to occur, a few things need to happen first and foremost.

.1 BP needs to be taken out of the Equation

.2 Congress or the President needs to give the EPA jurisdiction in the Gulf (even if this is temporary move) so NCCT can do proper toxicology testing on the Gulf Stream waters

.3 A panel of experts from the Oil Industry needs to be formed (which could include professionals from BP's engineering division)

.4 Engineering Models needs to be made to see what effects if any new problem solver may cause; and assess those possible outcomes

.5 All of the smaller vessels need to be moved out of the Gulf to allow 4 Super Tankers to be brought on site; to utilize their large vacuum systems and centrifuges; smaller vessels can be brought back into contain outside perimeter and the shorelines

.6 The Navy and Coast Guard should . up the containment with the expertise of the Oil Industry Experts; and all Oil Companies involved need to provide and make available all of the equipment they will need

.7 US Army Biochemical Division needs to bring in "FOX" M93A1 Vehicles to do complete air, water. and soil testing in all major populated areas along the gulf and within a 20 mile radius of the Gulf

.8 US Army Reserve and National Guard troops need be called in to provide the police call (cleanup for non military personnel) and placed on a 24/7 detail working in three separate shifts; with duty officers put in charge of the clean up

.9 US Air Force needs to be given a mandate to provide all logistics for the region in-conjunction with US Army CECOM to provide proper equipment, housing, food, and force readiness operation

.10 The US Treasury Dept. needs to take over financial evaluation; and keep track of overall costs of the clean up

.11 Last but certainly not least, BP needs to foot the Bill!

Once the spill has been contained and the situation is 5 by 5; Congress needs to put together an investigation team to assess any criminal actions if any on the part of BP; and levy fines or federal charges against those directly or indirectly responsible (if they had knowledge of any wrong doing by BP)

Respectfully

MolecularPHD

This is my assessment of this grave situation in the Gulf; there of course are many steps I left out; I am currently writing a complete task readiness report that I will be sending to the powers that be.



posted on May, 31 2010 @ 09:34 AM
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Originally posted by ANNED

Woodward Governor, while not the only people in the business, are the defacto standard for engine speed control in the industry. The UG-8 is the one that I am most familiar with. If installed on the gen sets it would have started to reduce fuel to the engine almost immediately and as the speed climbed above set point it would have eventually shut the fuel to the engine off.


Woodward governors are only for controlling fuel.
once you have another source of fuel be it crankcase oil, turbo oil. natural gas. a Woodward governor will not control a runaway.

In some cases even a intake valve will only slow down a runaway.

I had a diesel/propane mix engine runaway that would not stop even with the diesel off the intake valve closed and two CO2 fire bottles fired in the intake.
It ran for 5 more minutes on just the propane in the lines between the control valve and the engine.

Plus there was flame coming out the exhaust stack from the bad fuel air mix of crankcase oil and propane.

So much for adding propane and water injection into the intake of a diesel engine to cut the soot emissions and increase the HP.

The exhaust .er on a diesel is hot enough to light off natural gas.
heat the engine more by burning natural gas in it and every safety shutdown in the world will not stop a explosion.

[edit on 31-5-2010 by ANNED]


Good point. Being a controls person I was thinking about what could be controlled not the uncontrolled source of fuel / air. Thinking about it in that light makes it seem pretty logical that the engine could have been the source of ignition and nothing would have prevented it from happening.

The OP hit on this but if you've been in the industry any time at all it's pretty obvious that accountants run the industry. Shareholder mentality overrides proper engineering standards and good business practices (like maintaining what you operate, etc). They talk a good line on safety but in general it's about the bottom line not reliability and safety. I see it in every customer that I work for except one and they aren't a publicly traded company. Surprise. I spent 21 years working for a top ten company before going out on my own. The company I started with wasn't publicly traded when I started. It was probably the best time that I've had at work not counting now. Once they went public slowly but surely the turn to an accountant mentality began. I have to give the early President and VP credit. The former was an accountant and the latter was an engineer. They held on to the core values and blended the two disciplines until a merger triggered their golden parachutes and they were supplanted by accountants. From there it started downward. It's funny how a business can eventually make enough money to be self sustainable. They make money in spite of themselves but the employee base is not happy and that makes things very inefficient. I think that's the norm these days.



posted on May, 31 2010 @ 09:40 AM
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This whole thread I think just proved to me how ignorant people on ATS really are.

Have any of you guys seen the video of the official leak?

The GAS/oil(4000:1) is leaking not from the pipes that are in place anymore, its leaking from the actual ground of the sea, in multiple places. And its possible a #ing VOLCANO. There is leaking In other parts of the ocean as well, including 5 miles out in another location. The horizon incident was all done on purpose to cover up whats really happening, and possibly by NK for another reason too, nobody will ever know the true reason, ill leave it up to you guys to do that research.

The OPs post doesn't explain anything at all whats going on. And I cant believe most of you guys are still falling for this oil crap. ITS NOT ABOUT THE OIL ANYMORE. Its about the METHANE and the GASES they are purposely releasing that will eventually reach the ATMOSPHERE, and KILL. Ok? Do you guys get it now? Stop talking about well.s, and pipes and #, and do some research. All of the piping and work done is mostly #ed. I would agree that NK or a submarine exploded underneath the oil rig destroying the whole infastructure.

And thats why BP is delaying, they cant do jack #, its not an oil mans problem anymore, its up to the scientists now.

[edit on 31-5-2010 by adamo21]

[edit on 31-5-2010 by adamo21]



posted on May, 31 2010 @ 09:51 AM
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reply to post by Mike6158
 


All systems have manual E stops for those events that can not be prevented, but any system since the 1980ties that has any serious hazard, like explosion hazards, have automated systems that react to known problems, such as overspeed with a generator.

The larger systems normally have redundant shut down systems, and as I stated earlier, often both electrically and pneumatically controlled. The Deep Water Horizon was supposedly a high tech, new advanced drilling rig. It is hard to believe that their generators didn't have the proper emergency shutdown systems that are standard parts of such equipment these days. By the way, personally I think PLCs are overused these days, and are typically unnecessary components too prone to fail, especially in emergency shutdown systems. It is a good example of technology going backwards.

Detectors for explosive gases should be calibrated to go off long before the gas levels rise to the point of explosion. The systems I am familiar with require that you stay on top of them, keeping up with calibration, they are normally able to react in time to deal with explosive gas levels. As the technician described in the interview, there were blast doors on the generator house, which means it was set up for an explosion proof environment, which means that the normally 90% of the air to the room was constantly being recycled, and should gas sensors detect levels of gas lower than the lowest level allowed, the air into the rooms would have been shut down. Typically, oxygen sensors would be also installed to warn personnel of possible dangers. These types of systems should be installed anywhere there are gases with explosion capabilities, and this is required by the insurance companies whose regulations are often more strict that the government.

Once again the gas detectors are set to go off long before the gas levels rise to an explosive level, so the milliseconds required for these systems to react are not a factor. Modern systems are not that hard to maintain, and bypassing these systems is not only illegal but foolish. The only people bypassing these systems these days are people who don't know what they are doing.

Military stuff quickly becomes standard stuff, if not from the government regulations, than for insurance requirements.

Marine environments require explosion proof electrical enclosures, especially in environments where explosive gases might be present like oil drilling platforms. An explosion proof electrical enclosure is completely sealed off from outside air, door seals, and epoxy in all the incoming conduits. This means that when a circuit break does pop, or an fuse goes, any sparks will not be exposed to easily ignited gases. How can you not know this if you work on this equipment? The heavy duty enclosures will not heat up enough to set off any gas outside of the box unless a seriously catastrophic event occurred. Which would mean that sheeit had already hit the fan.

Things have changed a great deal since the 1970ties, and mercury manometers where phased out in the nineties, because they were prone to releases of mercury.

Shutting the air intake manifold is standard procedure for generator overspeeds these days, especially in environments with explosive gas environments, which is quite common. Once again, standard insurance requirements. These systems aren't that expensive, and are typically very reliable.



posted on May, 31 2010 @ 09:54 AM
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Was wondering if any of the experts here know of any flexible soft materials (such as nanotech weaves) that could be used to contain the spill or direct the spill until the relief wells are completed???

Rather than attaching new pipes, seems it would be possible to attach a flexible fabric to the leaking well and direct the spill to a pipe to be pumped to tankers above. I have read that these materials are stronger than steel and flexible.



posted on May, 31 2010 @ 09:58 AM
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Originally posted by Arbitrageur

Also one thing I'm not sure about...Pipe is normally lowed into the hole by its own weight, right? If the blowout is pushing against the pipe, its weight won't be enough to lower it, what technology would they use to force the pipe down the hole against the pressure of the blowout? I've worked in normal offshore rig operations before but I've never experienced a blowout.

So there's no doubt that pumping mud in the bottom, aka a "bottom fill" is the answer to plugging the leak.

I'm sure it occurred to them to think about how they could use the existing hole to do that, instead of waiting 3 months while they drill some new holes, don't you think?


I've got kinfolk that started on the floor and worked his way up to country manager for offshore operations overseas. I remember him telling me about a blowout on a rig that he was driller on (he wasn't the driller when it blew out). The BOP worked but not before sections of the drill string blew out, smashed into the cat. and smashed a few things up on location.

I think the thing that most people miss here is the enormous pressures involved and what they can do to steel pipe. I think that you are on the money and I also think that Top Kill was forced on them in a "do something, do anything, just do something" way.

I've been trying to make contact with people I know in the industry to confirm this but so far I've had no luck. The entire offshore industry is consumed by this leak and it's negative affect on a HUGE part of the gulf coast as far as employment goes in some way or other so getting a chance to talk to them has not proven to be easy. They're probably tired of talking about it. That said- (I'm repeating myself I know) The wells in the gulf that I'm familiar with, admittedly they are few, are predominantly natural gas wells. "Oil" is a secondary product in that it is a constituent of natural gas but it's not the primary component. For example- the inlet gas composition at a plant down in Mobile, AL that processes natural gas from platforms in the gulf was 88% Methane. It's not a "rich gas" stream. Another customer that I work for has a plant down near Grand Cheniere. They are a midline facility in that they have separation equipment between the gulf produced natural gas and a cryo plant. Their function is to remove oil from the gas stream before it is sent to the cryo plant. During normal operations the flow of oil is a trickle. They only receive oil in any significant volume when the people that own the line pig the line. They stick a foam pig in the line at the platform and it pushes the condensed fluid in the line into the facility. As the pig and column of fluid nears the facility the inlet scrubbers start dumping to the oil storage tanks. They have to control the rate of inflow at this point but the pigging operation is a relatively benign operation and they do not get a huge volume of oil into the facility. The stuff that collects in the line is partially the result of condensation and partially the result of some oil from the well. At high pressure and cold temperatures (like at the bottom of the ocean) some natural gas liquids will condense.

My point is- the DWH well is not an "oil well" in the sense that it's primary component isn't the thick gooey stuff like you saw with the Exxon Valdez spill. It's a natural gas well. The "plume" that we see on videos is the result of condensed natural gas liquids. They are pretty volatile if heated. Meaning that they want to be a vapor at warmer temps and lower pressures. That said, unless the NGL's come to the surface through some means of transport, the bulk of them may lay on the bottom or in lower layers and possibly flow into the Florida Plain where pressure is even greater and temperatures are even colder. I'm not convinced that the environmental catastrophe that has so many people wring their hands in agony is going to happen. I hope I'm right. We'll see...

[edit on 5/31/2010 by Mike6158]



posted on May, 31 2010 @ 10:03 AM
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reply to post by ANNED
 



The exhaust .er on a diesel is hot enough to light off natural gas. heat the engine more by burning natural gas in it and every safety shutdown in the world will not stop a explosion.


They can and they do, which is why it is extremely rare to see a gas explosion from a generator these days. More and more these systems are designed so that they can not be bypassed, to protect the manufacturers from liability.



posted on May, 31 2010 @ 10:11 AM
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reply to post by Mike6158
 



The former was an accountant and the latter was an engineer. They held on to the core values and blended the two disciplines until a merger triggered their golden parachutes and they were supplanted by accountants. From there it started downward. It's funny how a business can eventually make enough money to be self sustainable. They make money in spite of themselves but the employee base is not happy and that makes things very inefficient. I think that's the norm these days.


Which is why the whole free market concept is a huge con job. Once government stops enforcing the rules, they start letting people go who refuse to sign off on phony data. The competent people are let go, the incompetents take over, and everything goes to hell in a handbasket. That is the way things went in the eighties under Reagan and Bush I, and in the 00s under GW. Giant corporate leaches buy up the more efficient smaller companies who developed the technologies and the markets, and rape them.



posted on May, 31 2010 @ 11:26 AM
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reply to post by adamo21
 


Although we are all ignorant, I thought it would be useful to put the natural gas escape in perspective. Currently methane put in the atmosphere according to Wikpedia & the IPCC is around 600 teragrams per year. Although I am sure you can convert to cubic feet, for the rest of us this amounts to 85,860 million cubic feet(MMCF) of methane per day going into the atmosphere from natural and man made sources. If we take the most hysterical estimates of the escape rates of 19,000 bopd & 4000 ft^3/bbl then the escape from the blowout on a daily basis is 76 MMCFD or .089% of the current volume entering the atmosphere. 96.6 % of the methane is currently being disappated in the atmosphere turning into other molecules through natural processes.

If you are correct that the casing has split and it is blowing out of the seafloor then the relief wells will be the only solution. However your comment about blowing out 5 miles from the wellsite may be a report concerning the discovery of an underwater oil plume that is being carried from the blow out by ocean currents, not an escape from the seafloor.

I am sure I am in error and really appreciate insight as astute to get the ignorant masses on this thread enlightened and will avoid lighting up the grill so as to avoid setting the world on fire.



posted on May, 31 2010 @ 11:38 AM
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If the big puddle of stuff in the trench a few miles away is liquid methane, then anything causing an updraft could set in motion an explosive decompression of the gas. Suppose a charge was set and it went off, creating a big bubble of gas warm enough to not condense, or above the critical temperature for methane. The bubble would rise, and trail a column of methane toward the surface, and at some point, the methane would begin to gasify from it's liquid state. This could progress like a tornado in the atmosphere, only underwater, until the entire pocket of methane is trying to surface at one time. A similar event happened before, with liquid CO2 at a lake in Africa, killing almost everyone in the valley around the lake.
It has been conjectured that this effect has caused ships to go down when a gas-off event at the sea bed fills the water with enough bubbles so that it loses it's ability to float a ship.
In any case, a huge bubble of methane could be released if something disturbs that pocket of liquid.
Added link
Lake Nyos, Smithsonian link


[edit on 31-5-2010 by MelonMusketeer]



posted on May, 31 2010 @ 11:45 AM
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I was wondering if they could use a high pressure bellows of some kind, like So:



Insert it into the well, somehow.... but inflate it with drill mud, instead of air or water.

Plugging the leak... maybe that would work.



What if they just jut the Tube off at the riser... drop another drill . down the tube from the ship... to a few miles, and then start pumping drill mud through the drill shaft.

I guess that is "Bottom Kill"....


I've seen some people toying with the Idea of Nuking the Well:

rawstory.com...


Matt Simmons, founder of energy investment bank Simmons & Company, also says that there is evidence of a second oil leak about five to seven miles from the initial leak that BP has focused on fixing. That second leak, he says, is so large that the initial one is "minor" in comparison.





I just hope that the sedimentary material at that depth is solid enough to contain those pressures...

Otherwise, this could turn into a submarine Oil VOLCANO.

-Edrick

[edit on 31-5-2010 by Edrick]

[edit on 31-5-2010 by Edrick]



posted on May, 31 2010 @ 12:42 PM
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As an interesting Addendum... it seems that Goldman Sachs Shorted (bet against) the Gulf of Mexico, One Day before the sinking of the Deep water Horizon.

www.huffingtonpost.com...


In what is looming as another public relations predicament for Goldman Sachs, the banking giant admitted today that it made "a substantial financial bet against the Gulf of Mexico" one day before the sinking of an oil rig in that body of water.


The deeper we dig, the greater the stench, huh?

-Edrick



posted on May, 31 2010 @ 02:02 PM
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Heres my reply on how to stop the flow of oil in the gulf . Real Simple!!
Give it a super sized catheter and inflate it in the pipe about half way down break off from the catheter and plug it with concrete its that simple

Just remember there has been over 22,000 well drilled since the last big catastrophy in the gulf, now that Obama has stopped drilling, how many jobs are going to be lost how many families are suffering from that backlash /much less the current catastrophy going on in the gulf

And Mr. Obama please quit blaming everything on Bush its getting real old
and if you were so concerned about it why didnt you replace the people you say were getting cushy with the oil companies in the first place


Comments Please!!

[edit on 31-5-2010 by StumpDrummer]



posted on May, 31 2010 @ 02:30 PM
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You pretty much repeated a lot of what I said?

I'm aware that mercury manometers were phased out... but it happened in the late 80's. At least that's when we stopped using them... that might have been preemptive... that wasn't the point...

I think if you'll take some time and research the MTBF (Mean Time Between Failure) for PLC's then you'll see that they are far more reliable than mechanical components due to internal diagnostics and watchdog timers that they utilize. If they used a safety rated PLC, which is likely in an offshore environment, then the reliability and safety of the PLC based system is orders of magnitude higher than mechanical or pneumatic devices. As you say, things have changed a lot since the 70's. For the better.

Gas detectors DO NOT react in milliseconds. The trip occurs in milliseconds however the sensor doesn't instantaneously detect an increase in LEL. The systems that I am familiar with are set for 10% LEL Alarm and 20% LEL shutdown however when test gas is admitted to the sensor it takes seconds to react, sometimes 10's of seconds. Test gas is contained in a testing . and therefore causes a much quicker reaction. Another problem- If the gas is not sufficiently mixed with air then there is no explosive hazard and the detector will not detect LEL. If the release was as intense as it appears that it was it's entirely possible that the detection system didn't see it as an explosive event. The detectors are "point" detectors. They don't cover large areas unless they are of the infrared type (they shoot a beam if IR energy between a transmitter and detector. If it senses an explosive mixture then it triggers the alarm or shutdown). If you saturate a detector with a high volume of gas it will not sense LEL because the mixture is too rich to support combustion.

The NORMAL way to deal with higher energy level switchgear is to enclose it in a room with either a Type Z purge or some other method of assuring that the air is (A) air and not explosive and (B) changed a specific number of times per unit time. If a large volume of gas made it to the intake of the air handler quickly enough then nothing could be done to prevent an explosion. I've never seen generator switchgear in an explosion proof "fitting". They always control the environment in lieu of a ridiculously expensive and large "explosion proof enclosure. Maybe there was a couple of Size 0 or Size 1 motor starters in the field with explosion proof housings but I seriously doubt that anyone would take that approach with a gen set. Of course my experience with gen sets is limited to a max of 20,000 horsepower... which is well above their requirements.



posted on May, 31 2010 @ 04:37 PM
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Billyjack et al, thanks so much for being willing to share your expertise with us.

Would you be willing to take a look at this thread and the images therein and offer your opinion or at least some professional explanation to put people's minds at ease? People were seeing what appeared to be "flames" emanating from the well. It would be greatly appreciated and highly informative.

Thanks.



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