The use of interwell tracer tests is becoming increasingly important to the petroleum industry. In addition, the interwekk tracer test has proven to be an efficient tool to investigate reservoir flow performance and reservoir properties that control gas and water displacement processes. Tracer data has been used to reduce uncertainty attributed to well-to-well communications, vertical and horizontal flow, and residual oil saturation. Unfortunately, at present, analysis of the tracer response is still largely qualitative in nature, and most information provided through the monitoring of the tracers is not quantitative. Among the numerous papers found on tracer technology, only a few include history matching of water-tracer test results and only one paper includes history matching of gas tracer test results. This paper describes the development of interwell tracer analysis methods in the petroleum industry, from the first qualitative tracer study in the 1950s to the latest quantitative tracer study in 2000. The results of our study indicate that only a small number of interwell tracer studies employed advanced numerical modeling methods. In addition, tracer analysis methods in the petroleum industry are not well studied. However, they are far better studied in the hydrology industry. Tracer modelling methods deserve to be given more attention, so that petroleum engineers can take better advantage of results from costly interwell tracer tests.
