World estimates of the amount of methane sequestered in gas hydrates are enormous, but published estimates are highly speculative.  It is generally believed, however, the amount of gas in the hydrate reservoirs of the world greatly exceeds the volume of known conventional gas reserves.  Until recently, relatively little work has been done to assess the availability and production potential of gas hydrates.  Gas recovery from hydrates is hindered because hydrates occur as a solid in nature and are commonly widely dispersed in hostile Arctic and deep marine environments.  Proposed methods of gas recovery from hydrates usually deal with dissociating in-situ gas hydrates by heating and/or depressurizing the reservoir.  Among the various techniques for production of natural gas from in-situ gas hydrates, the most economically promising method is considered to be the depressurization scheme.

Despite the fact that relatively little is known about the ultimate resource potential of natural gas hydrates, it is certain that gas hydrates are a vast storehouse of natural gas and the national gas hydrate research programs of Japan, India, and the United States will significantly contribute to our understanding of the technical challenges needed to turn this enormous resource into a economically producible reserve.

In conclusion, will gas hydrates become a significant energy resource?  It is unlikely that we will see significant worldwide gas production from hydrates for the next 30 to 50 years.  However, in certain parts of the world characterized by unique economic and/or political motivations, gas hydrates may become a critical sustainable source of natural gas within the foreseeable future, possibly in the next five to ten years.

Natural Gas Hydrates: Resource of the 21st Century?