Flow monitoring and permeability measurement under constant and transient flow conditions

This paper considers the technique of diverging radial flow for the measurement of the in-plane permeability of isotropic or in-plane orthotropic porous media. Various causes for discrepancies and errors in the permeability thus determined are studied and finally a design for the experimental conditions and an experimental protocol is developed to minimise sources of errors. Numerical analysis methodologies are developed for flow under transient conditions through isotropic and orthotropic porous media, where in the latter case the flow ellipse axes may or may not coincide with the laboratory axes. Finally, these methodologies are validated by comparing the permeability data derived under transient flow with permeability data derived under constant injection pressure conditions.