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The water injection wellhead pressure equivalent to the highest pressure reached during <br /> the test is calculated by first determining the pressure at the casing shoe at the final pressure <br /> step, and then calculating the corresponding wellhead pressure with water in the well. For <br /> internal consistency of these calculations, depths of the 7-in. casing shoe (3,674 ft KB) and the <br /> DST pressure recorders (3,534 ft KB) are based on casing tally and drillpipe measurements, <br /> respectively. Although this casing shoe depth differs from the HLS log-based depth used <br /> elsewhere in this report, the difference is negligible for purposes of these calculations. <br /> Pressure at the 7-in. casing shoe at the last pressure increment is calculated as follows: <br /> Recorded pressure at 3,534 ft KB = 2,297.5 prig <br /> Mud column pressure between DST pressure <br /> recorder and 7-in. casing shoe = <br /> (3,674 - 3,534) ft * 0.499 psi/ft = 69.9 psi <br /> Pressure at 7-in. casing shoe = 2,367.4 psig <br /> Wellhead pressure (at ground level) with water in the well and negligible friction pressure <br /> loss is calculated as follows: <br /> 2,367.4 psig - 0.434 psi/ft * 3,660 ft = 779 psig, <br /> where the pressure gradient of 0.434 psi/ft is for nominal conditions of 70°F water with <br /> 2,000 ppm TDS. <br /> Mesquite Group, Inc. -34 <br />