Patent ID: 6050141
Filing Date: 2000-04-18
Classification: E21B,G01N,G01V

Abstract:
A borehole tool comprising:an elongated body sized to travel within a borehole;a transducer located in said body, for generating an acoustic pulse, said transducer being immersed in an intermediate fluid contained within a chamber of said body defined in part by a plate in contact with a borehole fluid to be measured and having a thickness such that a mechanical resonance frequency of said plate in a thickness mode is substantially equal to a resonance frequency of said transducer;means for receiving a signal from the fluid reflecting the acoustic pulse;means for gating the signal into a plurality of time slots;means for comparing received energies of the signal for the time slots to obtain a value indicative of the acoustic impedance of the fluid;means for normalizing the value to yield the acoustic impedance Z of the fluid;means for measuring the sonic velocity v of the fluid; andmeans for calculating the density .beta. of the fluid according to the equation ##EQU4##