瓦斯抽采
methane drainage
gas drainage
mine gas extraction and drainage
gas extraction in the upper corner
gas suction
methane extraction
gas extraction
pull out gas
抽采工艺
gas extraction technology
Gas drainage technology
抽采利用
gas extraction and utilization
立体抽采
three-dimensional drainage
抽采负压
suction pressure of the drainage system
抽采达标
reaching standards of gas extraction
卸压抽采
destressed gas extraction
relieved drainage
pressure relieved extraction
瓦斯割缝抽采
gas extraction by cutting