在新安煤田新建的三对矿井，主采煤层均为山西组2-1三软不稳定煤层。
There are three coal mines in Xin'an Coalfield. The Shanxi group irregular(2-1) coal seam has soft roof, soft coal and soft floor.
前言：通过对“三软”不稳定煤层采煤工作面瓦斯来源的分析，介绍了采用顶板岩石钻孔抽放解决瓦斯问题的原理和方法。
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.
着重探讨了煤层并壁不稳定机理，结果表明，煤层井壁不稳定是物理、化学、力学与机械等因素的综合效应。
The result shows that coal seam wellbore unstability is a synthetic effect caused by such factors as physics, chemistry, mechanics and machinery.
对煤层气藏进行评价的各种不同类型评价方法都曾经历了长期的技术演变与改进完善，其中包括岩心评价、测井、地震勘探、不稳定压力测试与生产分析。
A variety of reservoir-evaluation methods specific to coal reservoirs have evolved over time, including core evaluation, well logging, seismic, transient-pressure testing and production analysis.
对煤层气藏进行评价的各种不同类型评价方法都曾经历了长期的技术演变与改进完善，其中包括岩心评价、测井、地震勘探、不稳定压力测试与生产分析。
A variety of reservoir-evaluation methods specific to coal reservoirs have evolved over time, including core evaluation, well logging, seismic, transient-pressure testing and production analysis.
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