Vast quantities of natural gas exist as solid hydrates in the world's permafrost and deep sea environments. Russian experts estimate potential resources in excess of 107 TCF natural gas. Geophysical inference and direct sampling seem to substantiate the existence of hydrates where thermodynamic conditions are favorable. Their ubiquity provides an interesting link to another unconventional hypothesis of unconventional gas supply, namely the abiogenic origin of deep earth gas. A method to evaluate the abiogenic hypothesis is to compare the isotopic, trace element and compositional signature of hydrate samples from deep lake sediments in basins over crystalline basement rocks (Lake Superior) and over sedimentary rocks in connection with a producing, petroliferous province (Lake Michigan). Because of the complex relations between in situ dissociation and production of the free gas phase actual extraction methods will be technically complicated. A method to circulate warm surface water through a set of injection and withdrawal wells in deep sea hydrate deposits promises some advantages over conventional offshore drilling practices. Even if only a fraction of the claimed hydrate resources are accessible and producible the absolute amount is still very large compared to all other conventional and unconventional gas resources.

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