Steady flow through porous media

The increasing demands for oil, water, and food produced in an environmentally sound manner have placed emphasis on the manner of their production, a major part of which is concerned with flow through porous media. The movement of materials through porous media is of interest in many disciplines: in chemical engineering—adsorption, chromatography, filtration, flow in packed columns, ion exchange, reactor‐engineering; in petroleum engineering—displacement of oil with gas, water and miscible solvents including surface‐active agent solutions and description of reservoirs; in hydrology—movement of trace pollutants in water systems, recovery of water for drinking and irrigation, salt water encorachment into fresh water reservoirs; in soil physics—movement of water, nutrients, and pollutants into plants; in biophysics—life processes such as flow in the lung and the kidney. This paper reviews the fundamentals of steady flow through porous media: it discusses the pseudotransport coefficients permeability, capillary pressure, and dispersion and relates these coefficients to the geometry of porous media. It also discusses single‐fluid flow, multifluid immiscible flow, and multifluid miscible flow including the effects of heterogeneity, nonuniformity, and anisotropy of media.