A New Classification of Gas-Hydrate Deposits and Its Implications for Field-Development Potential

Summary A new classification of gas-hydrate deposits is proposed that takes into account their location (marine vs. permafrost), porosity type (matrix vs. fracture), and gas origin (biogenic, thermogenic, or mixed). Furthermore, by incorporating currently used Classes 1 through 4, which describe the nature of adjacent strata, a total of 16 classes of hydrate deposits have been identified. This new classification provides detailed information on the properties of the hydrate-bearing layer and adjacent strata that can be used for both scientific research and ranking of field-development potential. Using this new classification system, a qualitative ranking of field-development potential for different classes of hydrate deposits according to likely productivity, capital, and operating costs can be conducted. Finally, we demonstrate the usefulness of this new classification by applying it to 11 well-known gas-hydrate deposits worldwide.