Poststack Impedance Inversion with Geological Structure-Guided Total Variation Constraint

Impedance inversion is an effective method to estimate the properties of subsurface model from poststack seismic data. However, owing to the low quality of seismic data and other reasons, impedance inversion methods usually suffer from spatial discontinuities and low resolution. In order to overcome these problems, we have developed an impedance inversion method based on geological structure-guided total variation (GSGTV) constraint. Different from traditional TV constraint, GSGTV considers the spatial distribution of geological structures instead of imposing gradient constraints on impedance only in fixed directions (horizontal and vertical). Therefore, GSGTV not only retains the advantage of traditional TV that can preserve the edge of layer, but also overcomes the shortcomings of traditional TV that is only suitable for inverting block structures. This ensures that GSGTV can simultaneously improve the resolution and spatial continuity of the inversion result. The realization of impedance inversion method based on GSGTV constraint requires three steps. First, estimate the local structural orientation of the subsurface from seismic data. Then, construct GSGTV regularization term based on the local structural orientation. Finally, establish the inversion objective function and solve the function by the split-Bregman iterative algorithm. We compared the proposed method and the impedance inversion method based on traditional TV constraint with synthetic and real seismic data. The inversion results confirm that our method can improve the resolution and spatial continuity.