Experimental Tracer Response Curves for Fractured Cores

Abstract

In order to interpret tracer tests in fractured reservoirs, mathematical models have been used. However since model fitting is only an indirect process, it is necessary to examine the applicability of the model by comparing it to closely controlled laboratory flow experiments. In this way, the reliability and accuracy of the model can be evaluated and its functinal limits can be defined. This study set out to collect data which could be used as a basis to test the validity of mathematical models for tracer flow in fractures, and in particular, models developed recently at Stanford. Laboratory experiments were performed by flowing potassium iodide (KI) tracer through fractured consolidated cores. The response curves can be analyzed to estimate formation parameters such as fracture width in this case. By comparing the values of fracture width generated by the flow model to that measured on the actual core, the accuracy of the model can be gauged.