A Multi-Phase, Multi-Dimensional, Variable Composition Simulation of Gas Production From a Conventional Gas Reservoir in Contact With Hydrates

ABSTRACT A two-phase, three-dimensional numerical model was developed to simulate the dissociation and formation of hydrates (composed of water and any mixture of methane, ethane, or propane). This model was developed in order to address fundamental questions regarding the feasibility of production schemes for the utilization of this unconventional energy resource, gas hydrate, whenever a gas reservoir is in contact with a hydrate cap. These questions are also important in the design of conventional hydrocarbon resource production schemes from geologic zones in which hydrates are predicted to be thermodynamically stable. Results of the simulations indicate that massive hydrate can be dissociated without an external heat energy source, and that the water evolved from hydrate disassociation does not impose limits on the producibility of the reservoirs. Additionally, gas from hydrates was shown to contribute significantly to the produced gas stream. These results support the continued evaluation of gas hydrates as a potential resource, and indicate that conventional in situ recovery schemes may be effective in releasing gas from zones of hydrate stability.