Quantifying Enhanced Oil Recovery in Synthetic Media with MicroCT

Abstract : Enhanced oil recovery methods are tested and optimized in synthetic media, emulating porosity and permeability of real oil-bearing rocks. Such a medium was produced with sintered bi-disperse glass beads and microCT images (4 µm resolution) were acquired at different stages of fluid motion through the medium. Synthetic seawater with or without oil/ water emulsion was used to recover oil previously saturating the medium´s pores. The water was doped with KI to fine tune X-ray absorption. Thus, 3D images showing the beads, doped water and residual oil presented a 3-modal histogram. After denoising with a non-local means filter, the images were segmented and the distribution of residual oil ganglia was visualized and quantified. Probability density functions of volumes (~10^4 ganglia spanning 8 orders of magnitude) show well defined exponential behaviors for the displacement of oil by water, while the use of emulsions provides better recovery efficiency with larger numbers of larger ganglia