Sensitivity Analysis of Geomechanical Properties of Hydrocarbon Reservoirs Using Cross Plot Method in X-field Southeast Niger Delta

The sensitivity analysis of geomechanical properties of production-induced compaction of reservoirs in X-Field deploying well log data has been investigated. The study aims to utilize the estimated geomechanical properties to evaluate the relationships and sensitivity of cross-plotted properties to probable failure mechanisms, and to infer compaction due to production within the reservoir interval. The petrophysical analysis of this study reveals that the selected reservoir-3 interval across the three study wells exhibits better reservoir thickness, porosity, hydrocarbon saturation, Net-to-gross, and a lower volume of shale and water saturation. The reservoir interval is predominantly sandstone with varying intercalation of shale. The geomechanical properties results from the selected reservoir-3 interval reveals relatively low elastic moduli and UCS, as well as relatively high compressibility and Poisson’s ratio. This suggests that the dominant porous reservoir sands are unconsolidated and friable. The cross plot results revealed that the dominant reservoir sands are unconsolidated, friable, highly deformable, and brittle with very low mechanical strength as a result of low elastic moduli and high 𝛽, while the less porous and better consolidated shale is ductile. This depicts that the dominant reservoir sands are susceptible to mechanical failure due to the low elastic moduli, high deformation rate, brittleness, as well as low mechanical strength exhibited by the reservoir. Under overburden, this will give rise to increased compaction of the pore spaces of the reservoir due to the withdrawal of subsurface fluid during production.