Inversion of reservoir porosity and permeability based on velocity dispersion in 3D two-phase orthotropic crack medium

摘要

Reservoir parameter inversion is an essential geophysical method to quantify the reservoir volume. Oil-gas reservoirs are often presented as two-phase medium and anisotropic features, which lead to a great challenge for the reservoir parameters prediction. In the abstract, a new porosity and permeability inversion technology is proposed for 3D two-phase cracked orthorhombic media based on the BISQ mechanism. First, we derive the porous elastic wave equation of 3-D two-phase orthotropic anisotropic medium and build the relationships among porosity, permeability and phase velocity. Then we model and analyze the effects of porosity and permeability on velocity dispersion. The results show that it is feasibility to use the velocity dispersion to make porosity and permeability inversion. Finally, using the genetic algorithm, we implement the porosity and permeability inversion based on velocity dispersion, and also show some analysis for the algorithm stability and accuracy.