In conjunction with the LETC/DOE TS-IS Test, a computer simulation study was performed to a) help define the pattern site and configuration prior to the test, b) monitor the progress of the test during its operation, and c) help with post-test interpretation of the results. A multi-dimensional steam flood model was used to conduct the simulation. Results helped to define the inner and outer pattern sizes for the inverted 5-spot pattern. During the test vertical temperature profiles were matched which suggested significant under-running of the zone. Post-test coring and matching tended to confirm this behavior and the model also showed that initial oil saturation heterogeneity controlled the fluid movement during the experiment. The model results suggested that about three-fourths of the injected steam left the zone of interest and that fluid movement continued after the test was terminated. Studies of pre-steam flood air injection testing showed that such testing can give indication of areal heterogeneities so that steam movement during the test can be anticipated based on such heterogeneities.