Behind pipe evaluation using a nuclear tool

摘要

In relation to a cut and pull operation, a nuclear tool may be used for evaluating the composition of materials located behind a pipe lining the wellbore. More specifically, a downhole method may include emitting gamma rays into the pipe and the material from a source of a nuclear tool disposed in the wellbore; detecting gamma radiation scattered back from the pipe and the material with a detector of the nuclear tool; determining a high-energy range and a low-energy range for the gamma radiation; measuring count rates of the gamma radiation in the high-energy range (CR H ) and the low-energy range (CR L ); performing an analysis of (1) the CR H relative to (2) the CR L ; and determining a compositional equivalent for the material based on the analysis.