Summary of Air Permeability Data from Single-Hole Injection Tests in Unsaturated Fractured Tuffs at the Apache Leap Research Site: Results of Steady-State Test Interpretation

摘要

This document summarizes air permeability estimates obtained from single hole pneumatic injection tests in unsaturated fractured tuffs at the Covered Borehole Site within the larger Apache Leap Research Site. Only permeability estimates obtained from a steady state interpretation of relatively stable pressure and flow rate data are included. Tests were conducted in five boreholes inclined at 45 deg to the horizontal, and one vertical borehole. Five of the boreholes are 30 m long, one has length of 45 m. Over 180 borehole segments were tested between packers set 1 m apart. Additional tests were conducted in segments of lengths 0.5, 2.0 and 3.0 m in one borehole, and 2.0 m in another borehole, bringing the total number of tests to over 270. Tests were conducted by maintaining a constant injection rate until air pressure became relatively stable and remained so for some time. The injection rate was then incremented by a constant value and the procedure repeated. Three or more such incremental steps were conducted in each borehole segment while recording the air injection rate, pressure, temperature, and relative humidity. A description of field operating procedures used to insure compliance with QA/QC requirements is included.