Cement Bond Log Notes

SIE Style Surface Panel Setup Tricks

Set the oscilloscope at .1 ms/div (100 Ásec/div), .1, .2, or .5 volts/div, external trigger (EXT/10), and negative trigger slope.  (The foregoing assumes a Tektronix T922R scope.)

Adjust the amplitude GAIN to show attenuation of collar amplitude to about 50% of free pipe signal.  Insufficient gain will appear as excessive collar attenuation on the log.  See Table B below.

Adjust T2 to stay on the first negative arrival down to 5 or 10 millivolts on the recorder scale.  The transit time "floating gate" will thus trigger on the first arrival larger than said setting (see T2...The Easy Way for details).

First casing arrival for three foot spacing in fresh water (SIE):
Travel Time = 171 + (16.7 x D)
where D is the casing inside diameter (ID) in inches.

The two CBT Data Tables above are for 3-1/4 or 3-3/8 inch transmitter tools and three foot transmitter to receiver spacing.  For two inch transmitters, add 9 microseconds.  For four foot spacing, add 57 microseconds.

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Last 10-20-10