Observations of the Impacts of Millimeter- to Centimeter-Scale Heterogeneities on Relative Permeability and Trapping in Carbonate Rocks

Carbonate rock reservoirs are dominated by heterogeneity across a large and continuous range of spatial scales. We study the impact of heterogeneities on relative permeability and residual trapping for three carbonate rocks selected for their distinct spatial scales of rock texture. The Indiana limestone comprises millimeter-scale heterogeneities, the Estaillades limestone consists of half-centimeter-scale heterogeneities, and the Edwards dolomite includes decimeter-scale heterogeneity. Along with routine characterization of rock samples, steady-state N-2-deionized water drainage relative permeability measurements are made for each rock at two distinct total flow rates, at least 1 order of magnitude apart. The variation in flow potential across the core results in observations of fluid distribution, core-average relative permeability, and residual trapping obtained for a range of continuum-scale capillary number 0.02

Automated summary

This study investigates the impact of heterogeneity on relative permeability and residual trapping in carbonate rock reservoirs at various spatial scales. Experimental results show fluid distribution, core-average relative permeability, and residual trapping for different carbonate rocks selected based on distinct spatial scales of rock texture.