Could the Largest Oil Drilling Catastrophe Also End up the Largest Natural Gas and Climate Disaster in Recent History?
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Could the largest oil drilling catastrophe ever also end up the largest natural gas and climate disaster in recent history? Methane gas, we now know, caused the catastrophic explosion and ceaseless gush of oil in the Gulf of Mexico on April 20th, resulting immediately in 11 human deaths, and untold natural and economic loss. In part from earlier tragedies, methane's properties have been understood for decades. Yet neither BP nor government agencies paid much attention to the simple facts about the nature of natural gas.
- Where there's coal and oil, there's methane, a sister carbon product of the same organic material degraded over vast stretches of time.
- Methane in the air and upper levels of the ocean is a gas; but at the bottom of the sea, increased pressure makes methane a solid. In these depths methane is trapped in water in a slushy crystal called methane hydrate.
- In this crystal form, methane is lighter than water and when dislodged from natural sediments, which lock it in, it will rise. As it ascends, pressure decreases, and the methane expands, changing to gas.
- As the methane gas expands, a small bubble becomes a large explosive bubble, becoming a highly flammable and explosive plume when it reaches the air.
On April 20th, in the Gulf of Mexico, methane behaved as would be expected: dislodged from the bottom of the sea, methane crystals found their way into the well, rose up the drill column, expanded more and more, bursting though seals and barriers, until they kicked into the atmosphere, and exploded in flame from a nearby spark.
Dr. Robert Bea, Director of UC Berkeley's Catastrophic Risk Management Center, reported to AP that leaked BP documents reveal that dislodged methane hydrate, which had contaminated recently poured cement ,was the culprit in the Gulf disaster. There are tests to detect leaky cement, but there is no record of Halliburton, the cement contractor, using them. Deepwater Horizon workers told Bea that blasts of natural gas had troubled the rig in the weeks and days before the explosion, one so forceful that operations were shut down to avoid igniting the fumes.
At last Wednesday's congressional hearings, Rep Henry Waxman reported that on the day of the explosion, the rig failed a critical pressure test, indicating high gas levels in the well bore. Nonetheless, eager to move to lucrative production and move off of the expensive ($500,000 a day) rental rig, two hours before the explosion BP removed heavy mud (expensive, reusable drilling fluid) from the well and replaced it with sea water, creating the perfect low-pressure environment for the methane hydrate pockets in the cement to turn from solid to gas, and shoot up.
In its repair efforts BP has remained inattentive to deepwater drilling's natural nemesis -- methane hydrate. The 4-storey container lowered to the ocean floor to trap the gushing oil quickly clogged with the icy compound. At the very spot where methane crystals started their ascent only a week before, from a seabed known to contain a good portion of the world's methane hydrates, how could they have expected otherwise? ABC reported last week that natural gas flowing from the broken well is slowing the gush of oil, a sign to them that the spill crisis might be abating. But as the gas moves, it is only time before some if it evaporates into the air as methane or the carbon dioxide that methane readily oxidizes into.
According to geologist Gerald Dickens, frozen methane hydrate welling up from the ocean floor resulted in the mass extinction of the Late Paleocene period some 55 million years ago -- and similar claims have been made for what geologists call the Great Dying, the mass extinction of most life 200 million years before that, at the end of the Permian period. Climatologist Dr. Drew Shindell, of the NASA Goddard Institute for Space Studies, has recently demonstrated through computer modeling that methane when mixed with air is, molecule for molecule, the most powerful greenhouse house gas, 26 times more potent than CO2.