Inverse Modeling of Gravity Data with Two Layers Density in Sedimentary Basin Structure

Study of sedimentary basin structure and basement variation in the subsurface using gravity methods are very common in early stage of hydrocarbon exploration. Most of inverse modeling are designed with several series of juxtaposed vertical prism in the subsurface. In this study, we utilize two layers of vertical prism below each gravity stations to represent homogeneous density of sedimentary layer and basement in the subsurface. In order to reach best miss-fit data we used iterative calculation utilizing differences between observed and calculated data. Performance of iterative calculation will attempt to find solution of interface density in the subsurface. In this paper, we use two synthetic data of symmetrical sedimentary basin model for inversion performance test. The performance test will evaluate the effect of initial model, exploration well data, topographic data, and noisy data effect. Based on synthetic data test, the performance of iterative method provide small order of miss-fit data with residual solution model of noisy data in the range -44 to 35 meters. Real data application identified three shallow sedimentary layer and two deeper sedimentary layer in the study area.