Abstract: The average results of air- and water-permeability determinations are given for petroleum-reservoir sands in three Wyoming fields. The average amounts of materials of clay size in the sands and the types of clays present, as identified by X-ray diffraction methods, are also presented and discussed.
The sands are shown to be more permeable to air than to brines and more permeable to brines than to fresh water. Each of the sands exhibited different behavior when wetted by waters, and the percentage loss of permeability to waters, as compared to air, varied from sand to sand. The sand containing kaolins, illites, and mixed-layer clay (illite-montmorillonite) was found to be the most sensitive to water, and the sand containing only small amounts of kaolins and illites was the least sensitive. The sand that contained the most kaolins and illites was intermediate in water sensitivity. The water-permeability behavior of the sands and the dependence of this behavior on the clays present and the salinity of the water are discussed.