The key to produce this shallow gas is to use a set of negative suction technique besides that a series of measures for protecting the shallow gas-bearing formation must be adapted while drilling.
要把这类浅层气开采出来，除必须实施保护浅气层的钻井措施外，关键在于采用一套负压抽汲采气技术。
2
It can improve gas suction effect, reduce drilling hole amount and save construction investment.
采用优化后的方法可以提高瓦斯抽放效果，减少钻孔数量从而节省施工投入。
3
Based on the analysis of gas source at the working face with "three-soft" unsteady coal seam, the authors introduce the principle and method of gas suction by roof-rock drilling.