Modeling and inversion of the CSEM field in 2.5D anisotropic media with an adaptive finite element method
Su Qi1,2, Dai Shikun1,2, Zhao Dongdong1,2
1. School of Geosciences and Info-Physics, Central South University, Changsha, Hu'nan 410083, China; 2. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring, Ministry of Education, Central South University, Changsha, Hu'nan 410083, China
Abstract：We conduct a forward calculation of anisotropic media with the adaptive finite element method based on unstructured triangular meshes.In the simulation of tough topography and complex geological structures, the adaptive mesh strategy can ensure not only computational efficiency but also computational accuracy.The improved Occam algorithm based on Gauss Newton method can find quickly and appropriately the Lagrange multiplier under the condition of little dependence on the initial conditions.The forward modelings of a 1D VTI model and a classical 2D anisotropic ocean reservoir model prove the computational accuracy and efficiency.For a complex 2D anisotropic seafloor model, the inversion algorithm shows resistivity and buried depth of surrounding rocks, bedrocks and anisotropic anomalous bodies.Finally, tests on measured data shows the feasibility of the proposed algorithm.
粟琪, 戴世坤, 赵东东. 可控源电磁法2.5维自适应有限元各向异性正反演[J]. 石油地球物理勘探, 2018, 53(2): 418-429.
Su Qi, Dai Shikun, Zhao Dongdong. Modeling and inversion of the CSEM field in 2.5D anisotropic media with an adaptive finite element method. Oil Geophysical Prospecting, 2018, 53(2): 418-429.
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