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J- . <br />Circumjerentia[Acousric Scanning Too( (CAST) impedance values for fluids are very consistent and manifests itself as a fairly straight line on the log. Cement slumes, are <br />more variable and show up as curves with much more activity or variability. By analyzing [he value and the character of the impedance curves, it is possible to successfully <br />evaluate the cement quality of conventional and lightweight cements. Typical impedance values for common materials or fluids are: <br />Gas or av < .5 high activity curve response <br />Water 1.5 flat consistent curve response <br />Drilling Mud L5 - 2.5 flat consistent curve response <br />Lightweight Cements <l - 4 high activity curve response <br />Conventional Cements 2 - 6 medium to high activity curve response depending consistency of slurry <br />Cement Bond Log (CBL) tools evaluate cement bonding to pipe and formation by measuring the changes in sound waves traveling through casing, cement, <br />and formation. Log presentations include a pipe amplitude curve and aMicro-Seismogram ®display in the form of light to dark shades. The amplitude curve <br />in lightweight cements will not read as low as published values for conventional cements. Comparisons to lowest value and to free pipe value are necessary <br />to fully evaluate. Pipe signal will not completely disappear in lightweight cement as in conventional cements. <br />Respectfully, <br />Tom Riebel <br />HallibuROn Energy Services <br />Halliburton does not guarantee the accuracy of any interpretation of the log data, conversion of log data to physical rock parameters or recommendations which may be given <br />by Halliburton personnel or which appeaz on the log or in any other form Any user of such data, interpretations, conversions, or recommendations agrees that Halliburton is <br />not responsible except where due [o gross negligence or willful misconduct, for any loss, damages, or expenses resulting from the use thereof. <br />