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Appendix B - Packer Test Methods and Results 5 <br />2.4 Test Methods for Moderate Permeability Conditions <br />If the rock being tested was of moderate permeability, three tests were conducted in each interval: a flow <br />test, a shut-in test, and a bleed-off test. The procedure was similar to the procedure for low permeability <br />tests. However, the methods of analysis were slightly different. <br />Injection tests were also performed in moderate permeability units, using mine water supply. In this case, <br />the flow into the interval was measured by a flow meter (instantaneous and totalizing). Pressure and flow <br />were monitored essentially continuously during injection. If the test interval accepted water readily, a <br />"constant flow" injection test could be performed, by recording the "equilibrium" flow for a given injection <br />pressure. Care was taken not to overpressurize the rock, because inducing significant change in the <br />effective stress could lead to an overestimation of hydraulic conductivity in the native rockmass. <br />3. FIELD PROCEDURES <br />The general field procedures for conducting underground packer tests are as follows: <br />Insert the bottom packer and perforated pipe into the borehole. Attach the '/-inch, high pressure, nylon <br />air lines to the lower packer. Seal the hose tightly at the brass compression coupling at the top of the <br />packer, but loosely wind the air line around the perforated pipe. Adequate length must be allowed for <br />stretch between the two packers as they inflate. <br />2. Attach the upper packer to the top of the perforated pipe, and attach the air line which leads to the lower <br />packer to the bottom of the upper packer. <br />3. Attach a separate V4-inch, high pressure, nylon air line to the top of the upper packer. Insert the packer <br />is string into the borehole by adding measured sections of steel pipe. Tape the air lines to the pipe sections <br />with electrical tape as the packer assembly is inserted. <br />4. When positioned at the proper distance in the hole, connect the air lines to an external compressed <br />nitrogen tank, and inflate the packers to approximately 200 psi in excess of hydrostatic pressure. Check <br />to see that the packers are firmly seated. <br />5. When flow from the pipe stabilizes, measure the flow (Q) using the in-line flow meter, or a vessel and <br />stop-watch (depending on the flow rate and the meter capacity). <br />6. Perform the shut-in test. Close the valve and measure the pressure increase with time. Record the <br />pressures for approximately 10 minutes. <br />7. Perform the injection test. Using a hand pump (if the rock is very low permeability), inject water into <br />the test interval. Monitor the rate of injection, total volume injected, and pressure changes over time. If <br />the test interval is of moderate permeability, inject at a constant rate (if possible) for approximately 10 <br />minutes. If the test interval is of very low permeability, inject 2-4 fixed volumes (0.9 cc each), with a <br />10-30 second pause between injections. <br />8. Monitor the pressure decay following injection. Keep the valve closed, but stop injection. Monitor the <br />pressure decay over time, until the pressure has decayed 90% of the difference between the maximum <br />injection pressure and the equilibrium (shut-in) pressure. <br />9. Perform bleed-off test. Open the valve and monitor the pressure decay over time. Continue until the <br />pressure reaches 90% of difference between the equilibrium (shut-in) pressure and the static pressure in <br />the mine (zero [0]). <br />10. When the tests for that isolated interval are concluded, deflate the packers. If testing a new hole, remove <br />from packer testing apparatus from the borehole and drill the next segment. Repeat the testing <br />4109B.071116 Whetstone Associates