Three-dimensional Geoelectrical Forward Modeling and Numerical Simulation for NMR

In order to accurately describe the distribution of groundwater, a three-dimensional NMR response model was established. By the finite element method, the forward calculation was achieved. The distribution of NMR kernel function with different resistivity in homogeneous half space was studied by numerical simulation. With the help of the A, H, K, Q model, the NMR response to cover layer resistivity and surrounding resistivity were discussed. It shows that the distribution characteristics of resistivity were very important for the calculation of NMR especially in the low resistance medium. It provides an important reference for the inversion of NMR in the complex environment.