Tracer Tests in Oil Appraisal and Reservoir Evaluation: State of the Art

Abstract

This chapter describes the use of tracers in oil and gas reservoir exploration and evaluation. The tracers may be radioactive atoms or molecules that are detected by nuclear measuring techniques, naturally occurring stable isotopic ratios detected by electromagnetic isotope separation, or chemical tracers that may be measured by more or less conventional chemical techniques, e.g. gas chromatography. The topics selected for a closer description include: (1) tracers during drilling and completion of a well (mud infiltration studies, study of the “near wellbore” chemical reactions, control of mud circulation, measurement of injectivity profiles, location of cementing level, detection of casing leaks, selective acidizing and treatment of fractures); (2) tracers in reservoir evaluation (well-to-well flow studies for water and gas flooding); (3) tracers for EOR-chemicals (the study of surfactant and polymer behaviour under relevant reservoir conditions); (4) tracers for the determination of residual oil saturation (partitioning tracers in single well or in well-to-well experiments).