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Classical reservoir simulation considers rock compressibility as the only geomechanical parameter influencing field production. It is assumed to be constant or vary only with oil phase pressure. However, a conventional simulator still cannot explain some phenomena occurring during production, such as compaction, casing damage, wellbore stability, pore collapse, fault reactivation etc. In order to consider the geomechanical influence on the reservoir behaviour, it is necessary to use a coupled model: constitutive laws, mechanical properties of the reservoir and surrounding rocks, state of stress etc. On the other hand, the uncertainties inherent to the mechanical properties are enormous. To properly characterise a rock, lab tests are necessary, but cores are rarely available for destructive tests. Another solution is to use correlations between seismic response and rock properties. But, how reasonable and accurate are such correlations? This work presents a methodology of geomechanical modelling considering a sensitivity study of geomechanical parameters. Simulations with the commercial software STARS® were carried out, which identified the main geomechanical parameters relevant in flow simulation through a sensitivity analysis, based on a sugar cube model. Based on these results, the impact of geomechanics on reservoir simulation is illustrated by comparing permeability, porosity, oil and water production values generated by conventional and coupled simulations.
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