Methods for evaluation of 'in situ' coal permeability in underground coal mines using hydrodynamic test data

摘要

The paper presents methods for in situ evaluation of coal permeability paying special attention to methods invented in the Oil and Gas Institute - National Research Institute (INiG - PIB). Included are:•a slug test method and alternative interpretation of slug test data using procedure devised in INiG - PIB,•a method which uses injection of water with a constant flow rate into a horizontal drainage well and accounts for the three dimensional flow (invented in INiG - PIB),•a method which uses air pressure decay in an isolated segment of a horizontal/vertical well to calculate permeability and skin effect (invented in INiG - PIB).