Residual Fluid Blobs and Contact Angle Measurements from X-Ray Images of Fluid Displacement

Over the past decade a growing number of high resolution, three-dimensional CT images of multiphase porous media systems have become available, as well as the number of algorithms to analyze both the pore space and the fluid partitioning imaged within the voids. We describe the challenge in identifying triple points (points with three phases in contact) and an algorithm for fluid contact angle measurement from a multiphase digitized image. Despite the challenges and limitations on vertex positions in isosurfaces determined from a segmented multiphase image, the contact angle algorithm showed satisfactory ability to identify small angles when tested on an analytic example and gave results in agreement with the experimental wettability measurements for a well-studied Berea sandstone sample. We furthermore present visualization of the residual fluid blobs from the same sample and their qualitative behaviour which is in agreeement with conventional wisdom.