Posts Tagged ‘gas hydrates’

Unlimited Gas.

Monday, May 28th, 2012

Burning methane hydrate ice (blogs.plos.org)

People are getting quite excited.

With methane hydrates now a possible source of natural gas, we may never run out of carbon-based fuels. Well, never is a reach, but a thousand or so years might be the reality.

Methane seeps up from the Earth’s interior, and in the cold and pressurized sandstones of the world’s continental shelves, it is captured by water molecules and frozen in ice lattices, forming methane hydrates.

Methane hydrate ice: under pressure, water crystal lattice forms around methane molecules (giss.nana.gov)

A single methane molecule (CH4) is trapped insdide the lattice of water molecules (records.viu.ca)

Now it has become extractable. This past winter, on the north slope off of Alaska, the US Dept of Energy along with Japan’s Oil Gas and Metals National Corporation, and Conoco-Phillips Oil, successfully drilled for the trapped methane for 30 days.

They used two methods, both releasing the methane by decreasing the pressure on the hydrates.

One method was to pump CO2 down the drill hole to the hydrates in the sandstone, where CO2 then replaced the methane molecules. This sounds very enticing – a way to dispose of the CO2 from oil refinement by pumping it into deep-water, sub-surface sandstone. Win-win.

The second was to pump water under pressure down into the sandstone, releasing pressure on the trapped gas. Feasible, apparently, but environmentally embarrassing, It’s uncertain how well it works – at least no-one is saying much about it.

Now we’re heading into a decade or so of experimental drilling, somewhat like the days of initial exploration for natural gas in the 1970s.

But this is different. Gas hydrates occur everywhere on the slopes of the continental shelves. The US Gulf Coast alone has enough to make the US energy independent for the foreseeable future – it doesn’t have to come from just the offshore slopes under the frozen Arctic.

Methane hydrate deposits occur abundantly in the sediment in the deeper of the world's continental slopes (globalcarbonproject.org)

The US plans much more extensive experimental drilling. So too do Japan and China, who haven’t dared dream of energy independence until now.

What’s the reality here? We don’t know, but the source looks almost unlimited, and the experimental drilling and CO2 injection worked – methane was captured.

What if water injection is a more effective method? Perhaps public scrutiny and the increasing value of clean water will push the technology to CO2 injection in any case. Perhaps it is safer and kinder to the Earth than the fracking for natural gas that is sweeping the world.

What lies ahead should worry us all.

But then what?
Exxon-Mobile and all the other oil companies that appear to govern the world are probably ecstatic.
This is not the way to keep the planet from becoming than a hothouse.
This is the way to ensure it happens.

This is not good news.