A new cement integrity tool has been developed, the Segmented Bond Tool (SBT), which affords a complete cement bond analysis in one logging pass. An array of transmitter-receivers, mounted on six pads, are utilized to extract quantitative measurements of the cement bond in six 60 degrees segments around the borehole. In addition, by effectively mounting the transmitters and receivers in contact with the casing wall through the use of pads, many of the problems common to the standard mandrel-type tools are effectively eliminated. Experimental laboratory tests indicate that angular resolution of the tool is 60 degrees as expected and that channels as small as 15 degrees can be detected.
From conception of this new generation CBL to final product, several rigid parameters were demanded. Briefly these are:
Ease of interpretation.
Eliminate ambiguity of conventional bond logs by quantitatively depicting the bond condition around the casing (i.e. channelling).
Complete data acquisition in one logging pass in all casing sizes 4-1/2" to 13-5/8" in both vertical and deviated wellbores.
Be unaffected by gasified wellbore fluids, fast formation and slight tool decentralization.
The purpose of this paper is to determine the success of the SBT in fulfilling these goals. Presented here are four Canadian examples from widely varied areas having casing strings cemented with various slurries.