BP Robot Seriously Hampers Oil Spill Containment

ChiefMonkeyGrinder writes "A high-tech effort by BP to slow the oil gushing from its ruptured well head led to a large accident yesterday that forced the company to remove a vital containment cap for 10 hours. Robots, known as remote operated vehicles, were performing multiple operations at the disaster site when one bumped into the 'top hat' cap and damaged one of the vents that removes excess fluid, according to the US Coast Guard. The robots weigh around four tons, and are controlled from vessels on the surface using advanced IT systems with both manual and automated functions. BP removed the cap for nearly 10 hours ... in order to assess it after a discharge of liquids was noted from a key valve. The cap's removal left the oil gushing out of the wellhead, largely uninterrupted. Admiral Thad Allen, US National Incident Commander for the response, told the media that part of the problem was the number of robots conducting simultaneous operations at an immense depth. A dozen robots are circulating the wellhead." Another factor that may hinder containment even more is the increasing potential for tropical storms in that area of the Gulf.

Re:Oil, Tropical Storms, and Hurricanes

[MightyMartian]

The chief concern I've heard is that the hurricanes might drive the oil deeper into the wetlands, doing harm to one of the critical ecosystems in the area.

Re:BP engineers are morons...

[Hatta]

And then the pressure builds up behind the top of the wellhead, forcing oil through the porous sandstone compromising the integrity of the sea bed possibly causing a complete rupture of the ocean floor leading to the entire contents of the oil deposit rushing into the gulf. There's a reason they quit trying to top kill it. There's a reason they removed the broken pipe at the wellhead allowing more oil to flow into the gulf. This is bad, but the alternative is far worse.

Re:OK

[Idbar]

I guess the cool part is the robots. The other one appears to be history repeating [youtube.com].

Re:OK

[grandseer]

There are no robots down there. Robots use artificial intelligence to asses a situation and act accordingly. What we are using here are Remotely Operated Vehicles (ROVs) controlled by a human. No robots. Sorry.

Re:Large pipe?

[moosesocks]

That's basically what they're doing with the current cap, although it's a bit more complicated than that.

The blowout preventer is still stitting on top of the wellhead, which prevents them from ramming it down onto the floor. Cutting off the BOP presents another huge series of problems, and probably shouldn't be attempted.

The primary issue with capturing the oil is the insane amount of pressure at the wellhead. The oil is gushing out of the well, despite there being a mile-high column of water on top of it. Actually obtaining a seal around the pipe (and at those depths) is going to be nearly impossible.

Don't forget about the methane hydrates too. The extra pressure created by a capping mechanism causes the methane to solidify, and clog the pipe.

Re:Brilliant

[Thetawaves]

The well casing is ruptured below the sea floor. If they cap it, oil will begin leaking below the surface. This will cause extensive erosion leading to the collapse of the blow out preventor. This erosion will continue and leakage rates will continue to increase until the whole oil field depressurizes. In other words: The very best anybody will ever do is to leave this pipe wide open. It will only get worse from here, and substantially faster if they do cap it. Our only hope is with other means to depressurize this (relief wells).

Re:Undre Pressure

[madfgurtbn]

You could weld a valve onto the top, but if you try to close it, the pressure will seek relief elsewhere. If you get really, really lucky, it just blows out the weld and rejects the valve.

Actually, they are planning to put a "capping valve" at the top of the BOP soon, replacing the top hat thingy they have in place now. They are giving very serious consideration to unbolting the flange at the top of the BOP, then bolting a new riser on top.

Also, they are already collecting oil through from the side of the BOP, via the lines and manifold they were using for the top kill attempt, so even if they did seal the top of the BOP, there would still be some pressure relieved via those lines. However, since BP is not talking about shutting the top of the BOP, they must not believe there is enough pressure relief through the top kill manifold to ensure that the well casing won't fail.

Here's a quote from a recent conference call by BP:

"And then – and then in terms of the capping valve, I’ve always told you that we have three options that we’re working. That remains. The – we’re starting to favor the flange-to-flange connection. It brings some advantages in terms of its ability to hold back more pressure. In fact, we believe it has the potential to actually hold the full pressure of the well. However, its challenges are around installation and the teams have been working a lot on all of the different tools and equipment that would be required to do that."

Full transcript of the call is here. [bp.com]

Re:Undre Pressure

[blantonl]

The relief wells are being drilled so they can pump concrete into the well to plug it. "Relief" doesn't refer to "reducing the well pressure" - it means to relieve the existing well from it's duties.

The two "relief" wells are targeted to terminate an existing well.