TIME OF FLIGHT THROUGH MUD

摘要

Among other things, there are disclosed embodiments of devices, suitable for incorporation into well-logging tools, for the in situ measurement of the acoustic impedance of a fluid in the well bore, such as drilling mud. The device includes a sonic emitter that emits sonic pulses into a solid probe. The pulses are partially transmitted and partially reflected at opposite surfaces, and the decay of the amplitude of successive sonic pulses is used to determine the acoustic impedance of the fluid.

主权项

1. A well-logging tool for in situ measurement of the acoustic impedance of a fluid in a bore hole, the tool comprising:
an external housing; an acoustic emitter contained within the housing adapted to generate sonic pulses; an intermediate member having a speed of sound less than 5,000 m/s having an interior face, through which the sonic pulses from the emitter pass, and a front face, which at least partially transmits the sonic pulses into the fluid being measured; an acoustic receiver that receives successive echo pulses from the probe through the interior face of the probe and generates an echo pulse signal that indicates the amplitude of successive echo pulses; an electronic controller that receives the echo pulse signal and determines the acoustic impedance of the fluid.