This report presents a computer algorithm for determining the degree of heterogeneity among the layers of a reservoir. The algorithm uses the equations developed by Brigham and Smith that predict the behavior of a tracer slug flowing in a five-spot injection pattern. To illustrate the use and potential problems in the application of this algorithm, examples are presented using five sets of simulated field test data. One example using actual field data is also presented. iii TABLE OF CONTENTS ABSTRACT iii I. INTRODUCTION II. METHOD OF ANALYSIS 4 III. APPLICATION AND DISCUSSION OF RESULTS 21