A Critical Review, Modeling, and Evaluation of Petrophysical Properties Variation in Deforming Naturally Fractured Subsurface Porous Formations

Abstract

Abstract The petrophysical properties of deforming naturally fractured subsurface porous formations such as the porosity, permeability, relative permeability, capillary pressure, and Lamé's parameter can vary by the stress and thermal effects. The proper modeling and description of the variation of the petrophysical properties of deforming naturally fractured subsurface porous formations are examined and evaluated. The application of the proper theory and modeling approaches are presented and demonstrated by the analyses of the experimental data of the naturally fractured sandstone permeability dependence on temperature and effective stress. The dual-porosity nature of the naturally fractured porous formations is determined as the key factor in the proper description of the effect of stress and thermal deformation on the petrophysical properties. The threshold or critical stress and temperature conditions separating the fracture and matrix deformation modes, referred to as the stress and thermal shocks phenomena, are determined. The performances of the improved correlations are demonstrated by analyzing and correlating of the experimental data based on the modified power-law equation. The present approach applying the modified power-law equation is shown to generate high quality results.