A TYPE-CURVE APPROACH TO ANALYZING 2-WELL TRACER TESTS

The traditional approach to analyzing field tracer data generally invo lves a history-matching procedure that is time-consuming and frequentl y results in a nonunique solution. In this paper, we use theoretical f requency response functions to build type curves of ''transfer functio n'' and ''phase spectrum'' that have a dimensionless heterogeneity ind ex as a parameter to characterize a stochastic permeability field. The transfer function contains information regarding the amplitude-attenu ating characteristics of the heterogeneous medium, and the phase spect rum provides information about the spacing between the frequency compo nents of the input and output tracer pulses. In a manner analogous to type-curve matching for well testing, we can analyze field tracer hist ory by comparing the theoretical and field-observed transfer function and phase spectrum. This analysis leads to an estimate of the heteroge neity index and PV. We demonstrate the technique by analyzing field tr acer data from the Big Muddy field, WY, and compare the use of paramet ers obtained in scaling up. Results show very good agreement with the field data.