Pore characterization of unconventional reservoirs

Abstract

This study proposes an image-based idea for analyzing the complex geometric characteristics of reservoir spaces using various change curves of the pore geometric attributes to subdivide and evaluate tight reservoir rocks from micron to centimeter thicknesses. Using advanced imaging and image-processing technologies, in this study, we transform information from reservoir images into a vertical stratigraphy via an imaging-based method. The new parameter system incorporates three categories of parameters, size (S), morphology (M), and direction (D), to quantitatively and comprehensively characterize the pores of unconventional reservoir rocks. Given these three categories of the parameters, the curve at a certain depth value can be used to clearly identify obvious interfaces, which constitute high tip values. These interfaces may indicate that the hydrodynamic conditions, stress conditions of the reservoir, temperature and pressure, or other physical or chemical conditions changed significantly at these points, allowing the sedimentary compaction process to be well documented at the microscale level. This indicates that, from a micro-level perspective, we can find micro-evidence of the hydrodynamic conditions at the time of formation. Such information can help strengthen our understanding of the geological formation processes of unconventional hydrocarbon reservoirs.