Ray Impedance Inversion on the Tight-sand Gas Reservoir

In a tight sand gas reservoir, due to its complicated geology and extremely low porosity and permeability, conventional inversion methods cannot always accomplish the task of characterizing reservoir distribution. In this paper, we apply the ray-impedance inversion on a tight-sand gas reservoir. We perform inversion on constant ray parameter profiles, with robust estimate of wavelet and stable result of reflectivity series to start with. Comparing the inverted ray impedance with the acoustic impedance, the elastic impedance and shear impedance from the commercial software, as well as these elastic parameters extracted from well logs, it shows that the frequency-dependent ray impedance is superior in identifying fracture zone and the characterization of reservoir distribution for this tight-sand gas reservoir.