Numerical Rock Physics and Seismic Characterization of Fractured Hydrocarbon Reservoirs

Abstract

In many cases hydrocarbon reservoirs present fractures oriented in preferential directions, which in turn govern fluid flow and reservoir production. This type of reservoirs behaves as anisotropic media in the seismic range of frequencies. In this work we present a collection of finite element harmonic experiments to determine at the macroscale a vertical transversely isotropic viscoelastic equivalent to the hydrocarbon reservoir, which at the mesoscale is described as a fracture fluid-satured porous medium.
Each harmonic experiment is associated with a compressibility or shear test, defined as a boundary value problem with appropriate boundary conditions. The symmetry axis can be changed using an appropriate Bond matrix. This approach allows to represent different scenarios of geophysical interest combining numerical rock physics with wave propagation simulations in the subsurface and wells. In particular, using amplitude versus offset (AVO) simulations, it is possibly to infer fracture densities, presence of different fluids and reservoir permeability among others.