Things are bad enough in the gulf. There's a real, genuine disaster of historic proportions. We don't need new tin-foil hat conspiracy theories.
Yes there is a lot of methane gas. That doesn't mean there's a giant bubble waiting to explode and set off an earthquake or volcanic eruption. It DOES mean that huge amounts of methane are in the water and entering the atmosphere. And methane causes 20 to 70 times the greenhouse gas effect that CO2 does, according to wikipedia. Also, methane decreases Oxygen in the water, making it harder for life in the ocean to survive. Add to that the oil eating bacteria using up oxygen and the risk for dead zones increase. This is serious stuff, but not at all validating the methane bubble narrative.
I have already reported that the situation with the well is very bad-- that probably, a gas explosion, possibly methane, in the well, caused damage up and down the well, possibly breaking the casing, causing leaks throughout the well. That is believed to be the reason the "top kill" failed. Mud was coming out from multiple leak locations. It is also the reason that the relief wells, being drilled so that a "bottom kill" can be attempted-- again, injecting mud into the well to seal it-- will not work because of breaks in the casing.
Part of the reason there are breaks in the casing is because BP chose to use the cheaper option for casing, saving a few million dollars. Then they skimped on spacers used in well sealing process that Haliburton was contracted to do. Haliburton accepted this sub-standard situation and did the work anyway. That added to the risk that the well was never sealed properly to begin with. We don't know all the facts because the mudlogs have not been released which would tell us details.
First, here's the response I received from my anonymous (I do know who it is but am protecting his job) source in BP:
Here's what I asked him: "There's talk that there's a giant methane gas bubble waiting to explode and start a volcano and earthquakes in the gulf. What's your take? " He replied:
There is no 'cavern' under the Gulf. How are caverns formed? By water dissolving limestone. Over a huge period of time. Above water. I don't know the geology of the oil-bearing rock, but if it were limestone, those drills would be progressing a whole lot faster. Also, if you drill into the top of a cavern, then it is IMPOSSIBLE to cement a well. Remember how that's done? They shoot cement out the bottom and it flows up between the wall and the outside of the well casing. A cavern would mean that there was no wall.
There is no huge gas volcano ready to come forth. It's true that this well is 40% gas by volume, and that the average is 5%, but that's just more doomsday crap from conspiracy nuts.
While the reservoir is around 400-450F, and 13,000 psi, there's no 'bubble', unless you consider an entire underground geology to be a bubble. The thing is permeable rock, not a cavern.
At most, with a huge hole in the ground, it could probably flow 600K bbl/day - but no volcano.
And - if by 'explode', you meant 'ignite', then I'd ask where the ignition source is? Even if it started flowing at the max, no fire on the surface is going to traverse to the bottom; fire requires oxygen.
Earthquakes - if the well opened up 100%, then - eventually, some of the structure might collapse and cause an minor earthquake - but that's doubtful. Generally, as you pump, the land subsides - a very quiet event. Earthquakes happen when drillers inject hot water or whatever to crack the rock and bring oil or gas out more quickly, and then that's only because natural faults get lubricated. Denver had a bunch of these in the 70's (I was there for them). No big deal.
Much ado about nothing, really."
I also asked geologist Chris Landau, who has experience with drilling. He replied,
As far as the bubble is concerned. I say no. If I am wrong, all I can say is I learnt something. Is it not good to be wrong at least once per day. My reasoning follows.
Two links you might want to save to get quick details on how deep the next earthquake is that makes the news and how strong it is. We have a 7 on the richter scale, somewhere in the world every 10 days.
1961 earthquakes of 2.5 on the richter scale or greater in the last week around the USA, Alaska,Hawaii, Puerto Rico. None in the Gulf. See interactive map from the United States Geological Survey site