SLOW-WAVE IMAGING OF PERMEABLE ROCKS

A high-resolution slow wave imaging system based on attenuation measur ement of transmitted airborne ultrasonic waves was developed to study the inhomogeneous pore structure in permeable formations. Currently, t he threshold sensitivity of our system is approximately 100 mo, making possible the characterization of typical petroleum reservoir rocks wi th spatial resolution of between 0.5 and 5 mm in the 50 kHz to 500 kHz frequency range. The degree of disorder in permeable solids is of cru cial importance especially when the relative permeability is considere d. It is expected that this new technique can complement such methods as hydrodynamic dispersion measurements and petrography for characteri zing flow in porous rocks.