| 摘要 |
<p>A core holder is used in the nonsteady-state testing of permeability and other flow characteristics of a geological core sample. A reference pressure reservoir assembly contains a predetermined volume of test gas at a known pressure, and a gas operated valve admits this test gas rapidly to the upstream end of the core sample. The downstream end of the core sample is open to the atmosphere, and the pressure in the reference pressure reservoir assembly is monitored as it decays in time while the test gas passes through the core sample. The gas-operated valve is formed of an upstream plug, a gland fitting the plug, and a valve stem fitting into a generally cylindrical cavity formed in the plug and gland. The valve stem has an enlarged head at one end with an annular slot on a cylindrical surface thereof. This structure minimizes turbulence in the flow of the test gas through the valve assembly.</p> |
