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Rate and pressure data for the test are given in Figure 8.2 and Thble D-1. Although not <br /> as evident in the figure, the data in Table D-1 indicate that there were pressure spikes associated <br /> with the rate changes. These are believed to be a result of surges associated with adjustments <br /> of the pump truck throttle. They are momentary, however, and are negligible with respect to <br /> the pressure transient analysis. In Thble D-1, the right-hand column is titled "Calculated <br /> Pressure at Sandface at 4,400 ft". Values in this column were calculated from the measured <br /> pressure at 4,000 ft, which are also listed in the table. The calculation allowed for the additional <br /> 400 ft of water head and flowing pressure losses in the 5-in. liner, wire-wrapped screen liner <br /> and gravel-packed perforations. <br /> 8.4 Injection Test Analysis <br /> The data from the injection test were analyzed by two methods. The first method was <br /> a semi-log straight line analysis using a Horner plot to estimate the well's skin factor and the <br /> formation transmissivity (kh). As a confirmation of the semi-log result, a steady-state analysis <br /> was done using the well's measured injectivity index and Darcy's law to estimate the formation <br /> kh. The two methods yield reasonably consistent results. <br /> Shown in Figure 8.3 is a plot of sandface pressure versus Horner time. A reasonable <br /> straight line section is found between Horner times of about 60 and 46. The straight line has <br /> a slope of 55 psi/log cycle. Also needed for permeability and skin calculations is the bottomhole <br /> pressure at one hour shut-in time. This was found to be 1833 psia. These values along with <br /> known or estimated formation and fluid properties were used to calculate kh, permeability and <br /> Mesquite Group, Inc. -23 <br />