Non-linear elastic impedance inversion method supported by vector machines
Su Jianlong1,2, Mi Hong3, Wang Yanchun2, Zhang Fengqi2, Tang Jing4
1. Research Institute, Southern Branch Co., SINOPEC, Chengdu, Sichuan 610041, China;
2. School of Geophysics and Geoinformation Technology, China University of Geosciences (Beijing), Beijing 100083, China;
3. Chongqing Department, Geophysical Prospecting Company, Chuanqing Drilling Engineering Ltd Co., CNPC, Chongqing 402160, China;
4. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China
Abstract：Conventional elastic impedance inversion of elastic parameters is a process of establishing linear equations by the approximate formula, such as Connolly approximate formula, and then solving the equations. However, the relationship between elastic impedance and elastic parameters are completely non-linear. Therefore, we propose in this paper a new non-linear elastic impedance inversion method supported by vector machines. There are three steps in this method: 1Calculate elastic impedance on exact Zoeppritz's equations after partial angle gather stacking; 2Establish nonlinear relationship between elastic impedance and elastic parameters applying a training method supported by vector machines; 3Calculate the elastic parameters according to this relationship. Application results in model synthetic data and field data show that maintaining the stability as conventional impedance inversion methods, this method can greatly improves inversion accuracy especially for far-offset data or violent variation of elastic parameters.
