Posted on 05/05/2010 5:40:28 AM PDT by afraidfortherepublic
Minutes before the Deepwater Horizon exploded in fire, workers on the deck heard a thump, then a hissing sound. Gas alarms sounded and the rig shook.
Seawater and mud containing gas from the well spewed up through the crown of the derrick and rained down on the drilling floor; fumes reportedly moved into the “safe zones” where the electric generators are located. The generators raced out of control as they sucked gas into the air intakes.
When the electric power surged, light bulbs exploded, computers and other electric systems were destroyed, leaving the rig in darkness except for the light from fires and explosions that ripped apart walls, according to accounts derived from interviews with attorneys representing survivors, missing rig workers and their families, as well as experts in the field of offshore drilling operations.
Before the blowout, the rig's crew had been replacing heavy and valuable drilling mud with lighter salt seawater in the top section of pipe known as the riser —
(Excerpt) Read more at chron.com ...
Light off....Like out of a movie
It wouldn’t surprise me to find out that__________. (Fill in the blank)
Excellent article; Thanks for putting this one up. I think we are all learning there is a lot more to this than anyone realized. I knew oil drilling was complex, but it’s well beyond my knowledge or expertise.
Someone posted a link to another blog a few days ago, and I read comments from someone who purported to know what he was talking about, that once you hear the alarm, the only 2 things that can be done are to 1) Emergency activate the BOP and 2) evacuate the rig.
This sounds like an extreme event that may have exceeded the design specs for one or more components in the entire rig, and it could be years until they find exactly what went wrong. Right now the focus is on the immediate problem of stopping the blowout, but once that’s done the forensic investigation will kick into high gear.
There are ALWAYS warning signs with ample time to divert the disaster before it happens. There is a point where it is too late and this is precisely what happened.
The crew knew the potential after they displaced the heavier mud with salt water. (Maximum of 10.2 ppg.) If they were not on guard knowing the dangers in what they were doing, then this event was predictable.
They also made a grave error in not having a DDV in the production string, or at least set a retrievable plug in the casing.
This typical of BP and I hope they go broke. No other company in the industry is as drunk from the Liberal Koolaid than they are. They deserve all they are about to get for showing loyalty and support for this evil enemy Marxist government under Obama.
That nobody ever really finds out what caused this but the lawyers and media make something up anyway.
Just wondering if you have any special knowledge about the industry?
The writer clearly hyped up the scenario. The turbines would have shut down on overspeed upon injesting raw gas, usually set at 63 to 65 hz. Light bulbs exploding? High voltage would have been the only thing to cause that. Once again, over voltage relays would have prevented that. Computers blowing up? Naw, didn’t happen. They just lost all electrical power, except to equipment that was on UPS (uninterruptable power supply). Been there done that offshore for 30 yrs.
Anyone with technical experience in this industry can see plainly what went wrong. There was grave human error and a lack of safety equipment installed because BP has a tendency to cut corners to save money. I know them all too well.
This will not take years to understand. It is clear what went wrong right here and now. There were no “design specs” involved. It was simply that the crew and the consultants did not take the standard safety precautions, as well as, they failed to pay attention to the many warning signs that were present.
My husband, who holds a number of patents in offshore oil drilling equipment and who has spent many hours on off shore rigs installing machinery, made the same observation. He attributes this disaster to operator error, or to deliberate sabotage. He does say that most rig workers are pretty straight arrow, so sabotage is a long shot. But, if he were hiring a crew, he'd want a thorough background check on everyone boarding the ship.
This well had been giving some problems all the way down and was a big discovery. Big pressure, 16ppg+ mud weight. They ran a long string of 7" production casing - not a liner, the confusion arising from the fact that all casing strings on a floating rig are run on drill pipe and hung off on the wellhead on the sea floor, like a "liner". They cemented this casing with lightweight cement containing nitrogen because they were having lost circulation in between the well kicking all the way down.
The calculations and the execution of this kind of a cement job are complex, in order that you neither let the well flow from too little hydrostatic pressure nor break it down and lose the fluid and cement from too much hydrostatic. But you gotta believe BP had 8 or 10 of their best double and triple checking everything.
On the outside of the top joint of casing is a seal assembly - "packoff" - that sets inside the subsea wellhead and seals. This was set and tested to 10,000 psi, OK. Remember they are doing all this from the surface 5,000 feet away. The technology is fascinating, like going to the moon or fishing out the Russian sub, or killing all the fires in Kuwait in 14 months instead of 5 years. We never have had an accident like this before so hubris, the folie d'grandeur, sort of takes over. BP were the leaders in all this stretching the envelope all over the world in deep water.
This was the end of the well until testing was to begin at a later time, so a temporary "bridge plug" was run in on drill pipe to set somewhere near the top of the well below 5,000 ft. This is the second barrier, you always have to have 2, and the casing was the first one. It is not know if this was actually set or not. At the same time they took the 16+ ppg mud out of the riser and replaced it with sea water so that they could pull the riser, lay it down, and move off.
When they did this, they of course took away all the hydrostatic on the well. But this was OK, normal, since the well was plugged both on the inside with the casing and on the outside with the tested packoff. But something turned loose all of a sudden, and the conventional wisdom would be the packoff on the outside of the casing.
Gas and oil rushed up the riser; there was little wind, and a gas cloud got all over the rig. When the main inductions of the engines got a whiff, they ran away and exploded. Blew them right off the rig. This set everything on fire. A similar explosion in the mud pit / mud pump room blew the mud pumps overboard. Another in the mud sack storage room, sited most unfortunately right next to the living quarters, took out all the interior walls where everyone was hanging out having - I am not making this up - a party to celebrate 7 years of accident free work on this rig. 7 BP bigwigs were there visiting from town.
In this sense they were lucky that the only ones lost were the 9 rig crew on the rig floor and 2 mud engineers down on the pits. The furniture and walls trapped some and broke some bones but they all managed to get in the lifeboats with assistance from the others.
The safety shut ins on the BOP were tripped but it is not clear why they did not work. This system has 4 way redundancy; 2 separate hydraulic systems and 2 separate electric systems should be able to operate any of the functions on the stack. They are tested every 14 days, all of them. (there is also a stab on the stack so that an ROV can plug in and operate it, but now it is too late because things are damaged).
The well is flowing through the BOP stack, probably around the outside of the 7" casing. As reported elsewhere, none of the "rams", those being the valves that are suppose to close around the drill pipe and / or shear it right in two and seal on the open hole, are sealing. Up the riser and out some holes in it where it is kinked. A little is coming out of the drill pipe too which is sticking out of the top of the riser and laid out on the ocean floor. The volumes as reported by the media are not correct but who knows exactly how much is coming?
2 relief wells will be drilled but it will take at least 60 days to kill it that way. There is a "deep sea intervention vessel" on the way, I don't know if that means a submarine or not, one would think this is too deep for subs, and it will have special cutting tools to try to cut off the very bottom of the riser on top of the BOP. The area is remarkably free from debris. The rig "Enterprise" is standing by with another BOP stack and a special connector to set down on top of the original one and then close. You saw this sort of thing in Red Adair movies and in Kuwait, a new stack dangling from a crane is just dropped down on the well after all the junk is removed. But that is not 5,000 ft underwater.
One unknown is if they get a new stack on it and close it, will the bitch broach around the outside of all the casing??
In order for a disaster of this magnitude to happen, more than one thing has to go wrong, or fail. First, a shitty cement job. The wellhead packoff / seal assembly, while designed to hold the pressure, is just a backup. And finally, the ability to close the well in with the BOP somehow went away.
A bad deal for the industry, for sure. Forget about California and Florida. Normal operations in the Gulf will be overregulated like the N. Sea. And so on.
Just a mere 35 years of drilling, management and consulting experience from Saudi Arabia, Alaska, the North Sea and now the Williston Basin. (Currently improving the technology and drilling program in that field.)
bookmarked
Ping
They (BP) still failed to have a DDV (Down Hole Deployment Valve) installed in the intermediate casing string. (7”) This is a requirement in the North Sea, Alaska and now the Williston Basin even has a few companies starting to use them. (EOG & Marathon)
In the event of a loss of control, the well can be shut in remotely and will stop all flow to the surface, even if the surface equipment fails or is inoperable. This is a simple fix for future operations and this regulation will surely become a reality in the Gulf from here on out. This only adds about 5% to initial production costs. It's well worth the expense.
You described a lot of details from the event.
Can you link us to the source of that information?
As I’ve been reading of these “estimates” by the government of how much oil is escaping from the well in BPD, I’m moved to ask this question of someone with your experience:
Does it look to you like they’re reading the estimates/measurements of previous on-land blow-outs and gushers and simply applying those numbers here as a WAG of how much oil “could” come out of a blowout?
Because I’ve not read anywhere where someone (or anyone) has tried to make an actual, you know, *measurement* of the volume of oil escaping the well. The numbers seem to be inflated to either CYA or attract attention to me.
And let’s assume (I’m NOT saying the bureaucrats are correct, just posing a hypothetical) that these estimates of > 20K BPD oil are correct - would a blowout like this indicate a good find of oil? ie, some of the on-land blowouts we’ve had were precursors to long-lived, highly productive oilfields... could that be the case here?
"Penton said his client told him that the “seal assembly” — an important plug down in the well — had been set less than a half hour before the blowout."
Hmmmm???
mark
Where have you seen >20k BPD?
The coast guard and MMS both are using 5k BPD.
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