Patent ID: 8219319
Filing Date: 2012-07-10
Classification: G01V

Abstract:
1. A computer-implemented method of characterizing elastic properties of a subsurface formation at various fluid saturation conditions, the method comprising: estimating densities and bulk moduli of fluids and surrounding rock matrix material present in an invaded zone around a wellbore and beyond the invaded zone to record a set of log curves of density and bulk modulus of the fluids and the surrounding rock matrix material present in the invaded zones and beyond the invaded zone versus depth; recording a set of shale trend compaction curves in each wellbore; solving a set of response equations for rock and fluid volumes based on the recorded set of log curves and shale trend compaction curves to compute lithology, porosity and hydrocarbon saturation to build computer models to estimate hydrocarbon saturation for the rock matrix material penetrated in the wellbore; and using the estimated densities and the bulk moduli of the fluids and the rock matrix material near the wellbore, the shale trend compaction curves and the computed lithology, porosity and hydrocarbon saturation near the wellbore to characterize elastic properties of a subsurface formation at various fluid saturation conditions.