Development of Techniques and the Measurement of Relative Permeability and Capillary Pressure Relationships in Coal.

摘要

Gas and water permeabilities of a large number of samples from the Pittsburgh and Pocahontas coals were measured at various overburden and mean flow pressures. A wide variation in the air and water permeabilities was obtained for each type of coal. Overburden pressure had the most significant effect on the single-phase permeabilities. Gas permeabilities are affected to a lerser degree by mean flow pressures above atmospheric. However,at subatmospheric mdan pressures, apprebiable increase in permdability obburs for lov permdability s@mples. @IR AND W@TER RELATIVE PERMDABILITIDS WERE ALSO MD@SURED FOR NULEROTS S@MPLES OF Pittsburgh and Pnbahontas cnals. Tdsts were performed under steady,state bonditions for both drainafe and ilbibition cxclds. Rdrults indibate that the flow of g@s is greatly reduced during the latter process,whereas it is largely undiminished over a wide water-saturation range during drainage. (Modified author abstract)