Methane hydrates are the wildcard energy resource, which if successful could diametrically change the landscape of available energy resources. The volume of methane stored in hydrates is estimated to amount to twice the global reserves of all conventional gas, coal and oil put together. There is ongoing government and academia combined effort to better understand methane hydrates as energy resources and their role in Earth’s carbon cycle. Exploration advances are also coming into focus e.g. the government of Japan is sinking test drills to look for methane hydrate deposits believed to be trapped only tens of meters deep in the sediment under the Sea of Japan.
Gas hydrates occur abundantly in nature, both in Arctic regions and in marine sediments. Gas hydrate is a crystalline solid consisting of gas molecules, usually methane, each surrounded by a cage of water molecules. It looks very much like water ice. Methane hydrate is stable in ocean floor sediments at water depths greater than 300 meters. (USGS)
Unconventional gas reservoirs and methane hydrates
The number one problem with methane hydrate exploitation is the fact that the gas is highly explosive, nevertheless the resources are vast and global energy needs are running high. Exxon estimates that by 2040 global energy demand will rise by 35%, with demand in developing nations rising by 65%. This will put a pressure on finding more resources and as countries adapt to green energy policies to use resources with lower carbon footprint.
Gas (methane), has advantage in contrary to coal, as in the process of burning it releases 1/3 less carbon than coal. On the global scale and under carbon tax policies this number is incredibly important. Unconventional gas sources, weather shale gas or methane hydrates are important to increase geographical availability of gas resource.
Before shale gas boom in US, natural gas was highly restrained to Russia and Middle East reserves, forming structure almost similar to OPEC. Europe a region with flagships in green energy this year shifted from burning coal in place of gas due to high prices of gas, especially from Russia and cheap coal coming from US. For instance Germany in first half of 2012 burnt 37% more coal than in 2011, this number was even higher in Italy 83% and in Netherlands 86%. Even with steady growth in use of green energy, such as solar and wind power the European region has become more dirty in 2012.
Japan as potential frontier
The Fukushima nuclear disaster was a tipping point for government of Japan to come back to exploration for methane hydrates onshore of Japan, which were discovered in 2003. The country strives to gain more energy autonomy as it is important importer in uranium, coal, gas & oil; lacking almost any of these reserves. After Fukushima disaster most of the nation’s nuclear plants were shut down and forced power companies to depend on thermal plants, which are powered by liquified natural gas (LNG). This shift drove up Japan’s LNG imports to record highs in 2011 and 2012, and helped cause the country’s trade deficit to balloon to its highest level ever in 2012.
Government-affiliated Japan Oil, Gas and Metals National Corp. has begun the world’s first offshore test mining of methane hydrate from seabed layers, in an effort to tap into a potential new fuel resource.
As of January 28, the deep-sea drilling vessel Chikyu departed for the eastern Nankai Trough, 70 kilometers off the Atsumi Peninsula in Aichi Prefecture. The company drilled an offshore well last year at a depth of 1,000 meters to a methane hydrate stratum 300 meters under the seabed where the production testing is being conducted. It now plans to extract natural gas by inserting a pipe into the well, with the extraction beginning as early as March 2013.
The company plans to extract up to 10,000 cubic meters of gas per day over a two-week period. It is estimated that Japan’s coastal waters hold 100 times the amount of natural gas that is used annually in the nation.
For those interested more in methane hydrates there is interesting PDF file by ENRGY LAB outlining formation, potential, technologies and environmental studies done. It can be accessed [here].