METHOD AND APPARATUS FOR LOGGING FOAM CEMENT IN CASED BOREHOLES

摘要

An acoustic logging system that measures distribution of foam cement and other material in a casing-borehole annulus. The distribution is preferably displayed as map. A borehole tool utilizes at least one acoustic transducer with a known frequency response and mounted on a rotating scanning head that is pointed essentially perpendicular to the borehole wall. The response of the transduc er is used to measure an original impedance map of material within the borehole- casing annulus. A fast Fourier transform is used to generate a FFT map from the dat a comprising the original impedance map. The original impedance map is then combined with the FFT map using logic rules to obtain a final impedance map that is indicative of material within the casing-borehole annulus.