(165c) Digital Rock Physics for Predicting Flow and Petrophysical Properties of Unconventional Reservoirs

In unconventional reservoirs, a complex pore space is hosted by a heterogeneous matrix with varying minerals and organic components all of which complicate petrophysical interpretation during hydrocarbon exploration and appraisal. The nanometer-sized pores, limited pore connectivity, and sparsely distributed porosity cause extremely low permeability making accurate laboratory measurements of fluid flow challenging. In addition, the combination of varying mineralogy, lithology, and saturation affect the composite rock properties such as thermal and electrical conductivity and complicate reservoir characterization at the log-scale. Here, we present a digital rock physics (DRP) study of absolute and relative permeability, electrical conductivity, and thermal conductivity from high-resolution images. Images from focused ion beam scanning electron microscopy (FIB-SEM) and X-ray microcomputed tomography (microCT) are used to demonstrate the effect of scale and changing resolution on the DRP-predicted properties. High-resolution 3D FIB-SEM images at 10 nm/voxel are used to directly image the pores, organic matter, and matrix that vary at the nano- and micro-scales while microCT images at 20 um/voxel are used to capture textural and compositional changes that exist at the core, or millimeter, scale. Finally, anisotropy is presented in the context of the resolved rock features. The digital rock physics predicted properties and anisotropy provide a possible method to link nano-scale and micro-scale rock properties to those that can be measured at the lab and reservoir scales which may lead to future improvements in log interpretation.