Abstract

Primary objective of cement sheath evaluation logs is to determine whether the production, injection and other critical zones are hydraulically isolated. Many types of logs have been used to evaluate the placement of cement in the casing to formation annulus. Each logging tool has provided a significant advancement in the identification of cement placement and zonal isolation. During 1960s Cement Bond Log (CBL) was developed and in the 1980s Cement Evaluation Tool (CET) was introduced to measure the acoustic impedance of the material in contact with the outside of the casing.