Fluid Identification Based on Matrix-fluid Decoupled Joint PP-PS Wave Seismic Inversion

Summary Seismic reservoir fluid identification is the main goal of current pre-stack seismic inversion. Effective fluid bulk modulus is an effective fluid factor which can provide persuasive evidence for fluid identification. Under the theory of poro-elasticity, we deduced a PS wave linear AVO approximation equation based on effective fluid bulk modulus, dry rock matrix term, porosity and density. And we tested the accuracy of new derived equation by using a typical model. According to theory of joint PP-PS wave inversion, we tested the method on seismology of a real logging well data by comparing with single PP wave inversion. The result showed that the estimated parameters can agree with original data more accurately. Meanwhile, a real multi-component seismic data was used to verifying effectiveness and feasibility of new proposed algorithm. It showed exact effective fluid bulk modulus, dry rock matrix term, porosity and density estimated value can be obtained directly, which can avoid the error accumulation of indirect inversion. It can meet the demand of seismic fluid discrimination.