The problem of fluid factor inversion lies in the forward modeling using the reflectivities of inelastic media instead of e-lastic media for an accurate description of propagation.For seismic wave attenuation in inelastic media,a Q-based elastic fluid factor is obtained by disturbing the elastic fluid factor term with attenuation coefficient.The scattering equation of the Q elastic fluid fac-tor at the interface is derived under the assumptions of similar media and weak attenuation.The expression highly correlates with the P-velocity,S-velocity,and density terms in the context of complex number.The relationships between Q elastic fluid factor and P-and S-velocities are derived to obtain the equation of P-reflectivity of Q elastic fluid factor under above assumptions,and the re-lation between this equation and the reflectivity equation of perfectly elastic media is analyzed.Our method eliminates false bright spots on inversion sections,and thus it is possible to obtain accurate fluid responses under the assumption of attenuation elastic media.Field data application to Shengli oilfield shows more distinguishable fluid responses from surrounding rock responses com-pared with the routine method of fluid factor inversion.Our method mitigates the uncertainties of fluid detection to some extent and eliminates the artifacts generated by single-factor detection merely using amplitude.
国家科技期刊平台
NSTL
万方数据
