To date, our research has consisted of designing reservoir simulators capable of modeling the behavior of geopressured geothermal reservoirs. The only model we currently have operational is a single phase (water) multidimensional simulator of such reservoirs. The model is a finite difference solution of the momentum transport equation for water. The model is twodimensional, and either areal or cross-sectional studies can be run. The model allows for heterogeneous, anisotropic porous media. The effects of pore pressure reduction on fluid properties and reservoir parameters are included. Reservoir parameters include porosity, permeability, and formation thickness. Even though the presence of dissolved gas is not included in this model, its effects on momentum transport can be approximated by modifying the fluid compressibility.

We plan to use the model to examine the effects of rock compression and shale water influx on the performance of a well completed in a representative Gulf Coast geopressured geothermal reservoir. This will be done to aid in planning well design and production tests for an expected pilot well drilled into such a reservoir.

At this time, we visualize that a geopressured geothermal reservoir might appear like Fig. 1. A massive undercompacted sandstone body is bounded on the landward side by a growth fault. Seaward the formation grades into an undercompacted shale. At the top, the sandstone is bounded by a shale that allows no vertical movement of fluid. Below the sandstone there is an undercompacted shale. The fluid contained within the reservoir is a relatively fresh water. Hopefully, it is contaminated with natural gas in solution.

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