Extended elastic impedance inversion

Extended elastic impedance approach allows the projection of seismic
amplitudes to angles of incidence outside of the recorded angles, which helps express the rock properties in terms of impedance values.  A relationship between the extended elastic impedance and reservoir properties is investigated by correlation analysis (as a function of new angle, Chi) between EEI logs and available petrophysical logs such as V-shale, porosity and saturation, as well as lithology logs, such as gamma ray.  Once the optimum angle Chi is determined, AVO analysis is carried out to obtain intercept and gradient attributes, and their linear combination allows the determination of the reservoir properties.

 

Extended elastic impedance inversion results for (top) bulk modulus, (middle) Young's modulus, and (bottom) V-shale attributes.  A good lithology and porosity variation can be interpreted considering both bulk modulus and Young's modulus.  The middle part of the V-shale zone of interest is showing high volume of shale as was expected.