Question

1. A reservoir engineer has reviewed the literature on chemical tracers and has found that fluoro-benzoic acid is an excellent tracer for water break-through in sandstone reservoir.

a. He proposes to change it to benzoic acid because of cost considerations, why is that a bad idea?
b. Fluoro-benzoic acid is giving peculiar results in a carbonate reservoir. Propose a possible reason why the tracer doesn’t work like its supposed to and propose an alternative tracer.

Answer 1

A. Using a benzoic acid is a bad idea as it imparts pungent smell to the source and basically it is solid in state and takes time to dissolve in the water. Using it wouldn't be a good idea.

B. Tracer should be basically inert with respect to the carrier medium. Benzoic acid will be be converted into its carbonate derivative when contacted with carbonate source. Other inert tracers could be used based on detecting element chosen, end use of carrier medium, and its final purity required