The Dept of Energy has announced a "Test" between themselves, Japan Oil, and ConocoPhillips for "producing methane gas from hydrate deposits on the Alaska North Slope". This is probably a bit arcane but a) it's a sign of impending peak oil effects, b) continued extraction of fossil fuels which will result in more emissions of previously sequestered carbon, c) involve questionable technologies to scrape stuff off the ocean floor, d) doesn't contribute to moving to properly clean energy technologies
We should start with what is a "methane hydrate"? Methane clathrate, also called methane hydrate, hydromethane, methane ice, "fire ice" and natural gas hydrate, is a solid clathrate compound (more specifically, a clathrate hydrate) in which a large amount of methane is trapped within a crystal structure of water, forming a solid similar to ice. .. The worldwide amounts of methane bound in gas hydrates is conservatively estimated to total twice the amount of carbon to be found in all known fossil fuels on Earth. (see wikipedia link below) Basically that means it's methane frozen into ice. One interesting thing is you can touch a match to this methane ice and set it on fire.
It occurs in shallow waters, both in "deep sedimentary structures" (e.g. underneath the sea floor), and as outcroppings on the sea floor. They also occur in deep antarctic ice cores, indicating that 800,000 years ago Earth's atmosphere had high methane concentrations. It's primarily an underground phenomena (according to wikipedia), can occur off-shore in continental shelf areas, as well as on-shore. The hydrates deposits may conceal deeper methane deposits.
Methane is basically identical to what we call "Natural Gas". Methane is a very serious greenhouse gas, and is a carbon based hydrocarbon.
In other words, this is a fossil fuel. Extracting these methane hydrates will do all the same things we're concerned about in other uses of fossil fuels. It means releasing methane that's currently sequestered underground, releasing the carbon into the ecosphere, and will continue contributions to releases of greenhouse gasses known to influence global warming climate change.
This is related to the effect in Siberia and other arctic tundra areas, where the frozen tundra is melting leading to methane releases. The "clathrate gun hypothesis" suggests that releases of methane from melting tundra will lead to runaway warming. I wonder if the purposeful release of methane from the hydrate deposits would also trigger this chathrate gun ??
http://en.wikipedia.org/wiki/Methane_clathrate
http://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
Methane Hydrate Production Technologies to be Tested on Alaska's North Slope
Washington, DC — The U.S. Department of Energy, the Japan Oil, Gas and Metals National Corporation, and ConocoPhillips will work together to test innovative technologies for producing methane gas from hydrate deposits on the Alaska North Slope.
The collaborative testing will take place under the auspices of a Statement of Intent for Cooperation in Methane Hydrates signed in 2008 and extended in 2011 by DOE and Japan’s Ministry of Economy, Trade, and Industry. The production tests are the next step in both U.S. and Japanese national efforts to evaluate the response of gas hydrate reservoirs to alternative gas hydrate production concepts. The tests will provide critical information to inform potential future extended-duration tests.
The tests will utilize the "Iġnik Sikumi" (Iñupiaq for "fire in the ice") gas hydrate field trial well, a fully instrumented borehole that was installed in the Prudhoe Bay region by ConocoPhillips and the Office of Fossil Energy’s National Energy Technology Laboratory earlier this year.
Methane hydrate consists of molecules of natural gas trapped in an open rigid framework of water molecules. It occurs in sediments within and below thick permafrost in Arctic regions, and in the subsurface of most continental waters with a depth of ~1,500 feet or greater. Many experts believe it represents a potentially vast source of global energy, and DOE scientists have studied methane hydrate resource potential and production technologies for more than two decades.
The current test plans call for roughly 100 days of continuous operations from January to March 2012. Tests will include the initial field trial of a technology that involves injecting carbon dioxide (CO2) into methane-hydrate-bearing sandstone formations, resulting in the swapping of CO2 molecules for methane molecules in the solid-water hydrate lattice, the release of methane gas, and the permanent storage of CO2 in the formation. This field experiment will be an extension of earlier successful tests of the technology conducted by ConocoPhillips and their research partners in a laboratory setting.
Following the exchange tests, the team will conduct a 1-month evaluation of an alternative methane-production method called depressurization. This process involves pumping fluids out of the borehole to reduce pressure in the well, which results in dissociation of methane hydrate into methane gas and liquid water. The method was successfully demonstrated during a 1-week test conducted by Japan and Canada in northwestern Canada in 2008.
- End of Techline
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