Case Study 3 Messoyakha Hydrate Production in Permafrost

3 Case Study 3 Messoyakha (Hydrate Production in Permafrost) 

The Messoyakha field has been produced through both inhibitor injection and depressurization, as well as combinations of the two. The inhibitor injection tests, presented in Table 7.14 from the combined results by Sumetz (1974) and Makogon (1981, p. 174), frequently gave dramatic short-term increases in production rates, due to hydrate dissociation in the vicinity of each injected well bore. In the table, methanol and mixtures of methanol and calcium chloride were injected under pressure, using a cement aggregate. For long-term dissociation of hydrates, depressurization was used. 

FIGURE 7.30 Cross section ofMessoyakha field with hydrates overlying gas. (Reproduced from Makogon, Y.F., Natural Gas Hydrates The State of Study in the USSR and Perspectives for Its Use, paper presented at the Third Chemical Congress ofNorthAmerica, Toronto, Canada, June 5-10 (1988). With Permission.) 

FIGURE 7.31 Gas hydrate stability envelope at Messoyakha. (Reproduced courtesy of U.S. Dept, of Energy (Sheshukov, 1972).) 

Area of the pay zone Thickness of the pay zone Open porosity Residual water saturation Initial reservoir pressure Reservoir temperature range Reservoir water salinity Water-free gas composition 

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