Velocity modeling under joint constraint of multiple structural attributes: a case study of Enping Sag in Pearl River Mouth Basin

High precision velocity modeling in complex fault block area is an effective method to solve the problem of fault shadow in imaging profile. We developed a velocity modeling method based on the joint constraints of multiple structural attributes, including horizon, fault, and dip for the structural region A in the Enping Sag, Pearl River Mouth Basin, South China Sea. In the method, the initial velocity model is established based on existing drilling data and available geological knowledge, and then the joint constraints of structural attributes reflecting fault characteristics are added into the tomographic inversion. Finally, the refined velocity model can be obtained iteratively. It can retain more accurately the velocity difference between the two sides of the fault, and more consistent with the actual stratigraphic units. The seismic depth migration imaging processing based on the velocity model shows that the imaging of the fault shadow area in the imaging section is more continuous, the breakpoint is clear, and the imaging quality is obviously better than the old data.