There is currently a need in rock engineering for a coherent approach, which allows the identification and incorporation of the important parameters and mechanisms for any rock engineering activity. This is the case of reservoir numerical simulation studies of oil/gas recovery strategies in which geomechanical effects play an important role on the underlying physics of the recovery process. For example, during the depletion phase or the cold-water injection of high-pressure/high-temperature reservoirs, the stress state in and around a reservoir can change dramatically. This process might result in rock movements such as compaction, improvement of natural fractures, induced fracturing, and fault activation, which continuously modify the reservoir properties such as the porosities, the permeabilities and the fault transmissibilities. Modifications of such parameters strongly influence the flow pattern in the reservoir and ultimately the final recovery factor. In this work, a methodology is developed which enables the incorporation of key mechanisms and parameters to solve a numerical reservoir simulation problem that considers geomechanical aspects. The proposed technique utilizes an iterative-coupled reservoir-geomechanical modeling approach to capture the link between flow and in-situ stresses. In a validation stage, results from the coupled model are compared to ones obtained from a classical simulation approach (constant rock compressibility model). The usefulness of technique developed here is illustrated for reservoir performance forecasting of a giant Brazilian deepwater oilfield producing by water injection. The solution achieved to the real case problem revealed important geomechanical features that must be considered in complex oil exploitation project scenarios in which limited information and production uncertainties are present.

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