A highly sensitive, high fidelity, microphone employing piezo electric crystals that detect the disturbance caused by fluid movement downhole. Noise, or sound, is the disturbance created by mechanical energy moving through matter as a wave. A leak behind the casing where flow is constricted can create noise. Fluid moving through a hole in the casing can cause noise. Movement of fluid in channels that are present in cemented interval of a well can create noise. All these events can be detected by the use of a Noise Log.
The amplitude of the noise frequencies ranging from 200, 600, 1000 and 2000 hertz are measured. The noise log is often run in conjunction with a temperature log. They are primarily run in cased wells but can be used in fractured, hard rock environments exhibiting fluid movement from restricted fractures.
Below is a noise log detecting methane gas entering the well behind the casing at 1325 ft and 1410 ft.
Click on thumbnail for a larger image of the NOISE LOG sample log.
PDF of NOISE TOOL LOG
PDF of NOISE TOOL Specifications
to find more about:
Focus Dual Induction
Depth Specific Fluid Sampling Biological/Scale
Cement Bond Log
Casing Inspection Log (CITM)