Porous Media in the Oilfield (Invited)

The complex interaction of liquids, gases and solids at the pore scale is of interest in many areas of geoscience including enhanced oil recovery, hydraulic fracturing and carbon sequestration. This paper presents an overview of porous media in the oilfield. We begin with a review of the digital rock workflow that includes imaging, image processing, and the modeling of static and dynamic processes. We then review experimental approaches to image dynamic multiphase interactions at the microscopic level during drainage and imbibition. Modeling multiphase fluid flow at the pore scale gives us much insight to the physics at nanometer and micrometer scale. However, when interpreting and modeling porous media in the oilfield one must consider the wide spectrum of scales that must be addressed and the challenges in reconciling the physics and geology at these different scales. Finally, we address some of the challenges in understanding porous media introduced by the shale oil and gas revolution. Hydraulic fracturing technology is now allowing us to extract oil and gas from shales with nano Darcy permeabilities.