Deepwater Horizon well could become unchecked gusher

[jtabeb]

Re: Deepwater Horizon well could become unchecked gusher

Don't know if this guy is for real, but he claims to be a survivor of the rig. He gives his first-hand account of what happened.

[Roughneck]

Re: Deepwater Horizon well could become unchecked gusher

Roughneck: Any opinions, based on your experience, on why they cannot get any of the BOPs in the stack to close?

I have struggled with this and really don't have an answer. After listening to the tape of the person who says he was on the rig,perhaps the initial kick when they opened the stack was so great it damaged the controls to the stack or as you say something was preventing the shear from closing.

[ThePythonicCow]

Re: Deepwater Horizon well could become unchecked gusher

Don't know if this guy is for real, but he claims to be a survivor of the rig. He gives his first-hand account of what happened.

Cool interview with "James" on Mark Levin. Thanks, jtabeb.

Hopefully GRG55 can get a chance to listen to this and integrate this information with his excellent explanations.

[GRG55]

Re: Deepwater Horizon well could become unchecked gusher

I have struggled with this and really don't have an answer. After listening to the tape of the person who says he was on the rig,perhaps the initial kick when they opened the stack was so great it damaged the controls to the stack or as you say something was preventing the shear from closing.

The caller mentions that they finished cementing the liner, which is consistent with the information I have. He also mentions they placed a seal assembly, but the video clearly shows a gas flare blowing under the helideck, which I am sure must have been coming from the diverter, which means the annulus was open. Finally, with the liner cemented there should be no way for formation fluids to enter the wellbore unless either the cement job was botched, or something on the liner [like a lap] failed [or something even more bizarre that I can't even picture happened downhole]. The post mortem on this one is going to be interesting to say the least...

[jtabeb]

Re: Deepwater Horizon well could become unchecked gusher

Got it from ZH. I'm telling you, they have some damn good stuff (but you have to filter it from the really bad that they also put out).

[we_are_toast]

Re: Deepwater Horizon well could become unchecked gusher

Do you guys know anything about this technique? Seems like it could help, but this business
of working under a mile of water just seems so incredibly difficult.

BP PLC was preparing a system never tried before at such depths to siphon away the geyser of crude from a blown-out well a mile under Gulf of Mexico waters. However, the plan to lower 74-ton, concrete-and-metal boxes being built to capture the oil and siphon it to a barge waiting at the surface will need at least another six to eight days to get it in place.

[GRG55]

Re: Deepwater Horizon well could become unchecked gusher

I made mention of this in one of my earlier posts. It is an attempt at a creative solution to a difficult problem...how to contain the oil that is flowing until the relief wells can be drilled and used to kill the original well [or find a way to get the BOPs to close]. This is not a solution to the actual problem [the blowout], but instead it's a way to try to mitigate the effects of the problem until it can be solved - which now looks like it is going to take weeks or months.

And yes, everything that is done at these depths takes great care and takes time. They will have to cut the damaged and leaking riser off above the BOP stack at some point, and that is going to be a delicate and difficult operation.

I found this pic of a BOP stack via a post on Yves Smith's blog...for those that have never seen something like this before it may help put in perspective why so many of us with industry experience watching this want to understand what could possibly have gone wrong that not one single set of rams on the BOP stack can be closed. The probabilities of a complete failure of all the BOPs at the same time is incredibly low...but that seems to be what has happened, and at the worst possible moment. It's like a skydiver with not one but several reserve chutes finding none of them work...

[Roughneck]

Re: Deepwater Horizon well could become unchecked gusher

It may have been that the controls to the BOP were damaged in the explosion which would explain why they couldn't get them to work before abandonig the rig. However they have sent robots down and tried to activate the local controls. I am not too familiar with the deep water stuff so I'm not sure how the local controls operate. What is mind boggling is the amount of pressure it would take to have a blow out if they were, as I believe, cementing. During drilling the weight of the fluid is used to keep the pressure contained. When cementing you have the weight of the cement also.

[GRG55]

Re: Deepwater Horizon well could become unchecked gusher

It may have been that the controls to the BOP were damaged in the explosion which would explain why they couldn't get them to work before abandonig the rig. However they have sent robots down and tried to activate the local controls. I am not too familiar with the deep water stuff so I'm not sure how the local controls operate. What is mind boggling is the amount of pressure it would take to have a blow out if they were, as I believe, cementing. During drilling the weight of the fluid is used to keep the pressure contained. When cementing you have the weight of the cement also.

There's a picture doing the rounds on the net, allegedly showing one of the tethered remotes [ROV] at the underwater BOP panel trying to actuate the shear rams. These remotes have some limits to their lateral placement capability, so are susceptible to being driven off target by underwater currents [remember, in this case they are at the end of 5000 ft of cable and wires]. As a result the operators try to vector them on target with minimal cross-current. Apparently in the immediate aftermath of the accident the optimal path for the ROV host ship on surface was blocked by the burning rig. The picture is dated the same day the rig capsized.

The information I have is that they had finished cementing the production liner the day before, so the wellbore should have been filled with drilling mud of suitable density to be slightly overbalanced. Regardless, with no perforations into any of the potential producing horizons, and the production liner cemented at bottom, it would seem something had to have failed downhole to allow hydrocarbons into the wellbore.

[touchring]

Re: Deepwater Horizon well could become unchecked gusher

Interesting. Where does the power to light up the place and the machines come from when the rig itself has sunk?

[ThePythonicCow]

Re: Deepwater Horizon well could become unchecked gusher

The The Times-Picayune (New Orleans, Louisiana) site has these two graphics, showing basically what's going on and a map of the area:

[GRG55]

Re: Deepwater Horizon well could become unchecked gusher

Interesting. Where does the power to light up the place and the machines come from when the rig itself has sunk?

The tethered remotes are always operated from a service boat, not the rig itself. They are called "tethered" remotes because they are connected by cable and wire to the surface ship. The power for the propulsion, lights, hydraulics and all the steering commands come from the surface ship.

[flintlock]

Re: Deepwater Horizon well could become unchecked gusher

The The Times-Picayune (New Orleans, Louisiana) site has these two graphics, showing basically what's going on and a map of the area:

Great find cow. Best graphic I've seen.

Is it possible/likely the controls for the BOP were damaged in the initial explosion/fire and then the buckled drilling riser then damaged the BOP itself, preventing it from closing despite being manually activated?

[aaron]

Re: Deepwater Horizon well could become unchecked gusher

what about a nice bomb that is exploded above the oil reservoir but below the gulf floor?

[touchring]

Re: Deepwater Horizon well could become unchecked gusher

The tethered remotes are always operated from a service boat, not the rig itself. They are called "tethered" remotes because they are connected by cable and wire to the surface ship. The power for the propulsion, lights, hydraulics and all the steering commands come from the surface ship.

interesting, so the service boat is really the command center and not the rig?