メタンハイドレート資源開発研究コンソーシアム・生産手法開発分野の研究について

Abstract

The role of the Research Group for Production Method and Modeling is to develop practical natural gas production methods from methane hydrate resources off-shore Japan. While natural gas produces from methane hydrate resources, unique behavior occurs in the methane hydrate sediment due to the physical properties of methane hydrate, and it does not observe in the conventional gas production. Four research subjects have been settled and carried out in Phase 1.In the subject of “Characterization of the sediment”, in-situ analysis system of physical properties of methane hydrate sediment has been developed, and various properties of fundamental properties, frame structures and mechanical properties of natural core sample were analyzed. Finally, methane hydrate reservoir parameters have been clarified.In the subject of “Clarification of the dissociation behavior of the sediment”, to establish the models for behavior over the entire sediment from the pore scale at the methane hydrate sediment dissociation, the analysis of the mass and the heat transfer phenomenon at the dissociation were executed. And the specific behavior during production process such as ice formation, methane hydrate re-generation, changes in mechanical properties are modeled. These models were introduced to the production simulator.In the subject of “Development of the production simulator”, various calculation modules such as a dissociation rate, a consolidation property and a permeability property, were developed. Exclusive production simulator (MH21-HYDRES) and geomechanical simulator (COTHMA) have been developed. Also, the performance of MH21-HYDRES was confirmed through the international bench mark test.In the subject of “Development of the dissociation and the recovery method”, various dissociation methods were tested to establish an efficient, economical production method. Finally, depressurization method was proposed as an efficient method, and it was verified in the on-shore production test at the Mackenzie Delta/Canada.In this review, the research achievements of the Research Group for Production Method and Modeling were introduced briefly.