Predicting Relative And Absolute Variations Of In-situ Permeability From Full-waveform Acoustic Logs

This paper is a review of the application of full-waveform acoustic logs to in-situ permeability estimation. The slowness and attenuation of the tube-wave arrival in full-waveform acoustic logs is sensitive to variations in the in-situ permeability. The tube-wave slowness can provide a measure of permeability variations if corrections are made for formation and borehole variations unrelated to permeability. The Biot model can be used to estimate absolute permeability values from tube-wave attenuation measurements if all model parameters are known. However, the effect of mudcake on the tube-wave properties must be explicitly addressed before absolute estimates can be made with confidence. Shear-wave acoustic logs, used in conjunction with the tube-wave data, provide additional constraints on the permeability estimation problem.