New Logging Technique for Direct Measurement of Relative Permeability

Abstract A measurement system capable of in-situ measurements of formation permeability is described. The measurement method relies upon imaging the distribution of magnetic permeability doped fluid injected into a wellbore system through mutual inductance measurements between pairs of coils, and relating the change in distribution of this fluid over time to a direct measurement of formation phase permeability. Analysis of the mutual inductance measurement method shows a unique response to distributions of magnetic permeability for various coil spacings, and insensitivity to other confounding electrical parameters. The response of the mutual inductance measurement to several magnetic permeability distributions is shown, demonstrating the feasibility of the measurement technique to image the subsurface formation magnetic permeability distribution and provide in-situ measurements of formation phase permeability.