SPWLA Glossary

A form of radioactivity log used in production logging for the study of tracer movements and, therefore, fluid movements in the immediate vicinity of the well bore (e.g., in casing. tubing, annulus, open hole). Usually one or more slugs of radioactive material are ejected into the fluid phase to be studied, and the direction and velocity of the introduced slug is monitored over different parts of the well bore. Tracer logs are helpful in estimating fluid flowrates, points of fluid exit or entry into the well bore, crossflow, leaks, etc.