FULL WAVE Sonic

FWS SPECIFICATIONS

System Requirement ALT logger / Logger20
Diameter 50 mm / 68mm
Length up to 3.20m (dependant on configuration)
Weight up to 35 kg
Max. pressure 200 bars = 2900psi
Max. temp. 70º C
Power supply 70-140 V
Variable Spacing All traces synchronously and simultaneously recorded
Frequency of wave 15KHz
Sample rate configurable 2 μSec ->50 μSec
Wave length configurable up to 1024 samples per receiver
Dynamic range 12 bits plus configurable 4 bits gain incl.AGC
Logging speeds 5m/min @ 5cm sample rate
Logging Mode centralised
Log pre conditions Water or mud filled wells

APPLICATIONS

From an ultrasonic transmitter a signal in the range of 10 – 20 kHz is created and is registered at a minimum of two receivers during a fixed time interval.
From these gathered data the travel time of the p- and s- waves of the surrounding rocks can be calculated. A Sonic tool that includes one transmitter and receiver in each of the upper and lower parts of the tool is called a Compensated Sonic Tool. If the tool records information over the whole of the wave arrival time then it is known as a Full Wave Sonic tool.

Logging with a Full Wave Sonic is essential for the derivation of the elastic parameter and for the estimation of permeability and porosity. The results can be easily added to seismic methods.Using a Full Wave Sonic tool, later reflections and close boundaries or inhomogeneities (faults, etc.) will also be detected. From this information from an area up to 3 – 5 m around the well can be obtained. From this it can be seen that theFull Wave Sonic tool is a valuable supplement to tomography
methods, to get a close up of the well.
In the case of the presence of a casing the Full Wave Sonic can be used as a control log for the cementation or the clay sealing (Cement Bond Log).

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