煤矿抽放瓦斯
coal bed methane extraction
浅孔瓦斯抽放
gas extracting of shallow hole
瓦斯抽放监控系统
gas drainage monitoring system
煤矿瓦斯抽采
coalmine gas extraction and production
瓦斯抽采
gas suction
methane drainage
mine gas extraction and drainage
gas drainage
pull out gas
methane extraction
gas extraction
gas extraction in the upper corner
卸压瓦斯抽采
released methane drainage
pressure-relief gas extraction
预抽瓦斯
before hand withdrawal of gas
gas pre-drainage
远程瓦斯抽采
long distance gas extraction