An Alternative Hydrocarbon Indicator Based on Rock Physics Template

Reservoir fluid discrimination is an indispensable part of seismic exploration. Reliable fluid discrimination helps to decrease the risk of exploration and increase the success rate of drilling. Based on the H-M contact theory, a rock physics template was built in the domain of the crossplot of compressional modulus and ratio of compressional modulus and shear modulus. An alternative hydrocarbon indicator RPTI (rock physics template indicator) was proposed according the fluid trend in this rock physics template. This combined hydrocarbon indicator not only solves the problem easily caused by single indicator in discrimination, but also reduces the influences of human factors. A corresponding alternative elastic impedance inversion method was proposed based on the Bayesian theory to improve the accuracy of inversion results. The profile of this indicator is an intuitionistic interpretation of fluid contents. Real data tests demonstrate the applicability and validity.