The evaluation of pore-geometry networks in clastic reservoir lithologies using microcomputer technology

ABSTRACT The migration of fluids (hydrocarbon and aqueous) through reservoir lithologies is controlled mainly by the geometry of the pore networks. Geometric factors of most significance to fluid flow and reservoir quality, include pore size, pore network specific surface area (roughness), pore shape, pore connectivity, and pore tortuosity. Direct three-dimensional measurements of these geometric properties are at present not possible and pore geometry or “porofacies” usually is inferred from volumetric porosity, permeability, and electroresistivity data. However, in most clastic reservoirs, the macropore geometry is well represented by resin-impregnated thin sections. Using back-scattered electron imaging of lithologic sections, large amount of two-dimensional pore geometry data can be acquired rapidly by image digitization, processing, and analysis software on a mainframe or microcomputer.