The improved residual node density based gravity forward method and its application

Abstract

Gravity forward modeling of the geological model is a necessary part in the investigation of subsurface density structures, and is extremely valuable in developing and testing gravity data processing and inversion algorithms. In dealing with practical problems, the traditional block model based gravity forward procedure is time consuming, and cannot accurately forward the semi-infinite extended model. To deal with these problems, we proposed an improved residual node density model based gravity forward method. In this method, we firstly transform the density model into a residual node density model with a specific boundary condition; and then remove all the zero residual node density points; and then calculate the gravity anomaly with these non-zero residual node density points. We implement the proposed method in both 2D and 3D cases with Fortran language, and then applied it to Marmousi2 (2D) and SEG/EAGE salt model (3D) gravity forward modeling. The result demonstrates that this method is efficient and has advantage in forward semi-infinite extended model with absolute density by providing a specific boundary condition.