Application Of The Sonic Volumetric Scan Log To Cement Evaluation

Field experiments using the Sonic Volumetric Scanning tool for cement evaluation behind casing has demonstrated the potential application for this logging method. Imaging of the cemented zone has disclosed troughs in the cement, lack of cement and good cement over the zone of interest. Comparisons of the cement bond log, cement evaluation tool, caliper surveys and temperature logs with the SVS log demonstrates the ability of the method to show in detail voids in the cement, flow channels and the potential communications across zones that appeared to be well cemented using conventional logs. The imaging process of a volumetric scan presentation produces a sonic image that gives a pictorial display of the cement in place. The cemented zone can be further evaluated from transmittance and velocity scans. The image can be selected to include the casing to cement bond, the full cemented zone or the cement to formation bond. Sectoring, tilting and rotation of the image allows one to quickly make a first interpretation for any suspect areas. A more detailed study from transmittance and velocity data permits a reliable qualification of the physical properties of the cement in place.