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100 psi using the rig pump. Pressure was observed on a gauge at the surface and recorded by the DST instruments. The leakoff test data from Halliburton's report are summarized in Table 10.1. For redundancy, two DST instruments were used, but the results are comparable, and the data from Gauge No. 1263 were used for this analysis. As shown in the table, pressure was increased in six increments to a maximum "true initial pressure" of 2,297.5 psig at 3,534 ft KB, the depth of the pressure recorder. The observed pressure at the surface on the final increment was approximately 550 psig, and the mud density in the hole was 9.6 lb/gal. With each step increase of pressure, the recorder charts show a pressure spike and an instantaneous falloff to the "true initial pressure" for each stage. The pressure spike is characteristic of the surge and momentary back-flow of a mud pump. It would not normally be noticed on a conventional pressure gauge but is apparent on the recorder charts. The "true initial pressure" in Table 10.1 corresponds to the surface pressure gauge reading (except for mud column head) that would be observed on a conventional leakoff test with no downhole recorders. On Stages 2-6 of the test, there is a relatively long observation period between pressure increments, during which there is a gradual pressure decline in the range of 5.5 to 16.6 psi/min. This decline is apparently due to a minor leak in the mechanical system, rather than a formation breakdown, because the rate of pressure decline remained relatively low and generally decreased throughout the test. There were no indications of a formation breakdown, which would have been characterized by a rapidly accelerating rate of leakoff. The test was terminated before breakdown pressure was reached, so the results did not define an upper limit on injection wellhead pressure. Mesquite Group, Inc. "32