Reservoir Geomechanical Characterization of a Matured Deep Jurassic Carbonate Reservoir: Explaining stress effects on production induced Fault Slip

The Jurassic carbonate reservoirs in Kuwait have undergone significant pressure depletion (up to 4,000 – 5,000 psi) and in some areas even they experienced increase in pore pressure. Asset team plans to develop these reservoirs with more horizontal/multilateral wells in order to increase reservoir contact and there by productivity and reservoir recovery. However, drilling and deepening infill development wells in this area have become challenging due to considerable uneven differential depletion across the field. Unprecedented drilling complications including mud-loss, formation inflow, and differential sticking are observed. Noticeably, at least two wells showed reservoir pressure increase. Geomechanical evaluation is targeted (1) to provide geomechanical solutions to maximize drilling success through minimizing mechanical wellbore instabilities for newly planned (infill) wells; and (2) to evaluate stress sensitivity of the field-wide natural fracture and fault network so as to understand the impact of depletion on sealing capacity of faults and permeability of fracture system. This presentation discusses how a field scale 3D reservoir geomechanical model using all available data was built and evaluated the impact of production induced stress changes on reservoir behaviour and also discusses how Geomechanical characterization provided inputs on field development planning.