2-D Sharp Boundary Inversion Of Direct Current Resistivity Data

Direct current (DC) prospecting has a very extent applied in the geophysics exploration, no matter used to general investigation on metallic or nonmetallic mineral, or used to research geologic structure, the method can reach a very good result. So it is important to have a study about the two-dimensional inversion of direct current method.At present, direct current 2D inversion is the highlight. However, these inversion methods are commonly used to solve the practical problem, and often introduce model objective function based on the smoothest stable functional, so the results are much smooth and could not represent the geo-electrical interface clearly which make it difficulty in the geophysical and geological interpretation. Compare with these methods, sharp boundary inversion is being researched by more and more experts.Sharp boundary inversion method represents the earth subsurface in terms of 2D model consisting of a limited number of layers with laterally varying thickness in each survey point and each layer having uniform resistivity. In order to make the inversion stable and avoid the false structures, the differences in the resistivity between adjacent layers and the lateral variation in layer depth are both penalty. It also has the limitation in block body inversion and is inconvenient to calculate the sensitivity matrix.In this paper we introduce the sharp boundary inversion methods into direct current resistivity inversion, We have completed the algorithm about the sharp boundary two-dimensional direct current resistivity inversion method by researching the follows: direct current resistivity finite elements method, sharp boundary 2D inversion methods, OCCAM inversion methods and Jacobian matrix technology. We have tested the algorithm by using the synthetic data. And we demonstrate the inversion results; this has further confirmed the inversion algorithm universal serviceability.