Compaction Performance of Geopressured-Geothermal Reservoir Rock

The mechanical properties of intact shale samples and reservoir sandstone cored from a Gulf Coast geopressured-geothermal well have been measured in triaxial compaction tests at similar confining pressures. The results suggest that such shales exhibit a reduced Young’s modulus and increased bulk modulus as compared to neighboring sandstone. Additional uniaxial compaction and pore pressure drawdown tests were conducted on the sandstone in order to investigate the significance of rock compaction to reservoir performance predictions. The test data and existing porous media models indicate that, although partial decoupling of the fluid-solid motions is justified for uniaxial compaction conditions, pore volume compressibility can significantly influence the interpretation of well test analyses.