Scale Model of Stress Sensitivity for Fractured Low-Permeability Reservoirs

Abstract

There are heterogeneity, stress sensitivity and anisotropy in fractured low-permeability reservoirs, while the size of cores (the diameter is usually 25mm) in stress sensitivity experiment is limited by coring and experimental conditions and is not likely to be magnified, so the flow scale in experiment test is far less than the actual underground flow scale (reach the order of meters), which results in that the flow law of real reservoir cannot be directly described by experimental data. By using a series-parallel simulation of fractured low-permeability reservoir, this paper presents a scale model of stress sensitivity for fractured low-permeability reservoir. Core size, underground flow scale, fracture density, fracture occurrence and in-site stress are considered in the scale model. Two stress sensitivity experiments should be respectively conducted for porous cores and fractured cores; the scale model provides a method to deduce large scale flow law in real reservoir from the stress sensitivity experiment results with small size cores (25mm).