UPDATE: 3:37 p.m. Eastern The BP-Coast Guard response team just announced that the dome BP lowered over the main leak last night “has not failed yet,” which means that they tried it and had to remove it quickly. BP Press Conference.

Less than 72 hours after the explosion on the Deepwater Horizon offshore rig and the British Petroleum oil spill began, FireDogLake had discerned and blogged about the likely cause of the catastrophe: heat from the curing concrete had thawed methane trapped in icy water and the resulting methane bubble exploded when it reached the rig.

We even located a Halliburton PowerPoint presentation that explained the problem, and pointed out that there was not yet a solution in place.

The mainstream media finally caught up to us, over a week later. The Associated Press reports that according the rig crew the reason for the blowout was, wait for it…

A chemical reaction caused by the setting cement created heat and a gas bubble which destroyed the seal.

Deep beneath the seafloor, methane is in a slushy, crystalline form. Deep sea oil drillers often encounter pockets of methane crystals as they dig into the earth.

In a front page story, The New York Times reports that the rig crew told them:

As the job unfolded, however, the workers did have intermittent trouble with pockets of natural gas. Highly flammable, the gas was forcing its way up the drilling pipes.

This was something BP had not foreseen as a serious problem, declaring a year earlier that gas was likely to pose only a “negligible” risk. The government warned the company that gas buildup was a real concern and that BP should “exercise caution.”

At one point during the previous several weeks, so much of it came belching up to the surface that a loudspeaker announcement called for a halt to all “hot work,” meaning any smoking, welding, cooking or any other use of fire. Smaller belches, or “kicks,” had stalled work as the job was winding down.

By mid-April, the crew was in the mop-up stages of the operation. The day before the blast, workers from Halliburton, the oil services contractor, had finished one of the trickiest tasks in building a well: encasing it in cement, with a temporary plug of cement near the bottom of the pipe to seal the well.

–snip—

Just before 10 p.m., the crew was using seawater to flush drilling mud out of the pipes. Suddenly, with explosive fury, water and mud came hurtling up the pipes and onto the deck, followed by the ominous hiss of natural gas. In seconds, it touched some spark or flame.

It’s not clear how BP can credibly claim it did not foresee methane escape as a possible problem. If you look at the Halliburton presentation it clearly explains that the Gulf of Mexico is known to have deposits of crystallized methane trapped in the ocean floor in deep water. The presentation also explains that when heat generated by the cement curing process thaws the surrounding ocean floor under the cold deep water, it releases the trapped gas.

This was not some secret internal Halliburton memo. It was a presentation to the American Association of Drilling Engineers — a public forum for folks who know and need to know about this stuff.

Anyway, we’re happy to know that the MSM thinks this is a front page story; so did we, a week ago.

Mad props to Scarecrow for getting it on the front page in — ahem — timely fashion.