Well integrity evaluation using integrated geophysical well loggings

Well cementing operation is one important factors of well completion as it provides structural support of the casing and hydraulic sealing preventing casing corrosion and groundwater contamination. A wide array of approaches have been developed and applied for leakage detection, including pressure monitoring, radioactive tracer survey, and geophysical surveys. In this work, geophysical well logging methods were adapted to the assessment of well construction and integrity. Various wireline tools yielded physical properties in each borehole environment before and after the casing installation. Several of sonic, nuclear, and mechanical methods focused on valid information to evaluate casing integrity specially after curing concrete for 28 days. Using radioactive logs such as gamma-gamma and neutron logs, we particularly tried to characterize the annular space behind casing, and these well integrity evaluations with cement bond logs corroborated the reliability of the results. Additionally, we reexamined the cement-to-casing bonding condition on the effect of perforation damage. Borehole-based analysis could contribute efficiently to in situ condition evaluation of cementing in which uncontrolled releases of fluid or gas occur.