Developments in Synchrotron X-Ray Microtomography With Applications to Flow in Porous Media

Abstract

Summary High resolution computed microtomography (CMT) with synchrotron X-ray sources provides the ability to obtain three-dimensional (3D) images of specimens with a spatial resolution on the order of micrometers. Microimaging capabilities at Brookhaven Natl. Laboratory's Natl. Synchrotron Light Source have been enhanced to provide larger and higher resolution 3D renderings of pore networks in reservoir rocks at a fraction of the time required in previous first generation scanning methods. Such data are used to model single and multiphase flow properties in digital images of real porous media. Pore networks are analyzed for tortuosity and connectivity measures, which have been elusive parameters in transport property models. We present examples of porosimetry simulation through network modeling to produce initial water saturation and residual oil distributions in a water-wet pore system. Furthermore, pore networks can provide the boundary condition framework for more rigorous simulations of displacement, such as in the lattice Boltzmann simulated waterflood example provided. Direct comparison between simulation and experiment is also possible. CMT images of a 6-mm subsection of a 1-in. diameter reservoir core sample were obtained before and after flooding to residual oil. The fluid distributions from CMT, lattice Boltzmann waterflood simulation, and percolation-based network modeling were found to be highly correlated. Advances in 3D visualization will allow even greater digestion and interpretation of phenomena dependent upon pore interconnectivity and multipore interactions.