Wettability Studies at the Pore Level: A New Approach by Use of Cryo-SEM

Abstract

Summary Cryo-scanning electron microscopy (Cryo-SEM) is used to study the wettability of reservoir rocks from fluid distribution at irreducible water saturation, Swi, and residual oil saturation, Sor. Results on mixed-wettability cores point out the importance of composition, distribution, and accessibility of minerals in determining the macroscopic behavior of the rocks. For the studied samples, wettability of sandstones is related to the presence of kaolinite, while wettability of carbonates seems to be related to pore-size distribution.