Anisotropic Seismic AVO Inversion And Organic Matter Content Prediction In Shale Gas Reservoirs

Shale gas dessert prediction is an important task for seismic exploration of shale gas.Unlike sandstone and carbonate oil and gas reservoirs,shale gas reservoirs have significant inherent anisotropy,so it is necessary to study dessert prediction methods based on anisotropic seismic inversion.Organic matter content is an important shale oil and gas geological dessert,conventional seismic prediction of organic matter content relies on high-precision density inversion,and density seismic inversion is particularly prominent in the face of strong anisotropic shale formations.In view of the above problems,this thesis first analyzes the petrophysical experimental test data and logging data of shale at home and abroad,compares the sensitivity of different elastic parameters and anisotropic parameters to organic matter content,and finds that there is a good correlation between the σ of anisotropic parameters and organic matter content,which provides a theoretical basis for subsequent seismic quantitative prediction of organic matter content.Then,on the basis of the existing seismic synchronous inversion method based on the three approximate formulas of VTI medium reflection coefficient,a new strategy of step-by-step inversion of anisotropic parameter σ is proposed,and finally,combined with the support vector regression(SVR)algorithm,the quantitative prediction of organic matter content is carried out by the anisotropic parameter σobtained by inversion,and the above method is applied to the actual seismic data of shale gas exploration area in Sichuan Basin,and the anisotropic seismic inversion and organic matter content prediction results are more consistent with the logging data.This thesis provides a new method for inverting the σ of anisotropic parameters,and a new idea for the seismic quantitative prediction of shale gas organic matter content.