The detailed study of oil sands in the laboratory yields considerable information relating to their capacity for storing fluids, the movement of fluids through them, and selective retention.
Effective pore size is related to grain size distribution in a particular manner for each sand. The effects of capillarity and gravity vary with pore size and nature of the wall. Some pore walls selectively adsorb tarry constituents; others do not. Permeability usually varies with time.
This paper is a brief summary of 5 years’ work on oil-bearing sands and limestones in the laboratory of the United States Geological Survey.