Research On Seismic Anisotropic Parameter Inversion Method Based On Rüger's Formula

Recently,fracture reservoirs are becoming the main research direction of exploration and development.Among the most fracture prediction methods,predicting fractures by using P-wave information is an economical and feasible method.Fracture prediction based on P-wave azimuthal AVO becomes a research hotspot.The paper starts with Rüger's formula,the theory basis of azimuthal anisotropy AVO,disscusses the relationship between P-wave reflection coefficient with incident angle,azimuthal angle and Thomsen's anisotropic parameters by numerical simulation.The anisotropic parameter inversion formula based on Rüger's formula is derived and the stability of inversion method is discussed.The research indicates that the stable inversion results can be obtained by using the wide azimuth prestack seismic data.Further,the inversion method is applied to the actual data.In order to compare with the inversion results,multi-scales fracture prediction by actual data is conducted at first.Macro-scale fractures are predicted based on poststack geometric attributes,meso-scale fractures are predicted based on prestack amplitude attributes,and finally the fracture development of target horizon is analysed comprehensively.Then the anisotropic parameter inversion based on Rüger's formula is applied to the actual data and the inversion results are compared with the multi-scales fracture prediction results.The results show that the inversion effect is relatively ideal,and the feasibility of the inversion method is verified.