Cement job evaluation has always been a major problem. Acoustic and ultrasonic logs are widely used to assess the quality of the cement job but even experts experience difficulties in locating cement on a bond log.

Bond Index (BI) has been the only interpretation method to make quantitative evaluation of the cement job. Un-fortunately, BI is far from being an exact figure and in many cases it will not be a valid method to use. Moreover, whenever BI is valid, it is very difficult at present to choose the right references for doing the interpretation. This paper demonstrates that the evaluation of cement jobs can be significantly improved when the design and actual cement job data are taken into consideration. Integration of this data, linked to characterizing the cement by its acoustic properties rather than its compressive strength, allows a calculation of all reference values for a better BI interpretation, and prevents misinterpretation in many cases. Field cases are also discussed which show the validity and the added benefits of the new integrated approach.1 

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