Geophysical Journal | 2002 volume 24 6

Approximation of a complicated cracked-porous section by a model of a triclinic gyrotropic medium

© A.P. Sorokin, G.V. Meged'

The opportunity of approximation of a heterogeneous discrete anisotropic geological section by a model triclinical gyrotropical medium is considered. Such a model most adequately corresponds with various seismic-geological conditions of a real section. Frequently tanks of hydrocarbons are represented by fractured-porous collectors saturated with a multiphase fluid (gas, petroleum, a condensate, water, hydrates, or a mix of these fluids). During the interaction of elastic waves with local heterogeneity of the geological section there are effects of complex polarization of both shear and compressional waves. Thus, the time and spatial dispersion of elastic waves that is reflected in changes of amplitude-phase characteristics of a full vector of seismic fluctuations is observed with dissipation of energy. Most reliable information about the structure of emptiness space and the character of fluid saturation in the near-borehole space at distance up to hundreds of meters from a chink can be received according to a technological complex multiwave polarization 3D seismic survey, a polarization method of vertical seismic profiling - PM VSP, logging and results of petrophysical laboratory testing of a core. Authors develop a method of the estimation of the stress state of environmental medium, spatial distribution of fractured formation on the indicative surface of the Poisson ratio n (n), definitions of the direction of the best permeability of the section and the character of fluid saturation.

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