粒状試料による石炭のガス透過率測定
1982 年 98 巻 1128 号 p. 80-84
詳細
1982 年 98 巻 1128 号 p. 80-84
Methane in a coal seam flows into a gas drainage bore hole through a two-step process; firstly diffusion through solid coal and secondly flow along interconnected fissures.
The purpose of this paper is to estimate the gas permeability of solid coal which contains few or no fissures in it. This permeability is thought to be useful for understanding gas flow characteristics of gas drainage bore holes in a virgin solid coal seam. The apparatus used in this experiment is shown in Fig. 1. As the smaller the coal particle, the fewer the fissures in it, powdered coal samples ranging from 20mesh to 100mesh were used for this experiment. Basing upon Darcy's law, the equations describing gas emission from powdered coal and change of gas pressure in the flask were derived. Comparing the calculated gas pressure change with the measured ones, gas permeabilities of two coal seams were estimated as approximately 10-10 darcy. Owing to the low gas permeability of solid coal, gas drainage from coal seam is thought to be difficult if the coal seam does not contain any fissures. In addition to this, experimental values of gas permeability agree well with the easinesses of gas drainage from in-situ coal seams.
