Stress field changes and faulting regimes analysis for determining fault reactivation possibility in cap rock and reservoir due to production & pressurized in Aghajari Oil Field - Iran̓s South West

Production and injection of fluid may cause hydraulic fracture, shear fracture at crack levels, or re-activation of faults and existing discontinuities by reducing effective stress by changing the pore pressure and corresponding changes in the stress field. Therefore, the deformation of the earth, seismic occurred, the reactivation of discontinuities and the impermeability capacity of the rocks surrounding the reservoir-caprock are considered important factors in the implementation of projects involving the production and injection of gas in underground spaces. Successful strategy in reservoir development is inevitably of geomechanical studies and modeling of reservoir. The construction of a comprehensive geomechanical model includes the stress position, a function of depth (direction and amount), the physical properties of the reservoir rock and its formations (rock resistance and elastic modulus), pore pressure estimation, description and distribution of fractures and faults. In this paper, one-dimensional geomechanical model constructed in the studied field was described using IP (Interactive Petrophysics) software, and by analytical modeling, the possibility of reactivation of the field faults, the possibility of fractures occurring during the operations of injection and production, and the critical amount of changing pressure of injection and production to produce tensile and shear fractures, have also been studied and evaluated.