A Novel Approach Linking Structural Restoration and Multiphase Fluid-Flow Modeling Using 3D Geomechanics in a North Kuwait Giant Carbonate Reservoir

The Mauddud reservoir is a Late Cretaceous carbonate reservoir dominated by midramp packstones with an average permeability of approximately 30 md. The spatial distribution of initial porosity and permeability using classical geostatistical methods proved difficult to history match the production data of the Mauddud reservoir in north Kuwait’s Sabriya field. Structural restoration followed by geomechanical forward modeling were conducted to obtain representative 3D porosity and permeability distributions prior to production. By performing coupled fluid-flow geomechanics simulations, the spatial and temporal variations of rock deformation, shearing, and dilation response can be reliably predicted. As a result, the change in porosity and permeability can be dynamically updated in the reservoir simulations, providing more realistic and accurate analysis of pressure and saturation distributions as a function of time within the reservoir. With pressure information and its progression rate and saturation, reservoir development decisions can be optimized with greater certainty and improved recovery factor. Structural restoration “back-stripping” modeling was performed to describe the structural evolution through geological time. Geomechanical forward modeling in geological time was performed and the results were validated with log measurements in the offset wells. Based on the geomechanical forward-modeling results, an initial porosity distribution was obtained for the reservoir