Inversion methods for elastic parameters and fracture parameters of monoclinic media induced by two groups of inclined fractures

Fractures significantly impact oil and gas production by altering the mechanical properties of subsurface rocks. This study investigates the forward and inverse problems associated with monoclinic anisotropic media, which arise from the presence of two sets of inclined fractures within an isotropic matrix. We first derive the stiffness matrix for this monoclinic medium by applying Schoenberg's linear slip theory. Subsequently, we employ the point spread function and the steady phase method to derive and simplify the reflection coefficient equation for seismic waves interacting with this complex medium. Finally, we verify the rationality of the method by using synthetic seismic records and actual seismic records. The proposed equations and inversion techniques offer a more accurate framework for characterizing monoclinic anisotropic media affected by inclined fractures, thereby enhancing the interpretation of subsurface structures in hydrocarbon exploration.