穿层钻孔煤或瓦斯喷出机理及防治关键技术研究

发布时间：2018-03-19 20:35

本文选题：煤或瓦斯喷出　切入点：发动机理　出处：《中国矿业大学》2014年硕士论文　论文类型：学位论文

【摘要】：我国煤矿瓦斯赋存条件复杂，低透气性煤层居多，普通钻孔瓦斯抽采效果不甚理想，需要采取其他卸压增透措施予以辅助。理论分析及工程实践均表明：钻割一体化水力割缝技术是目前提高瓦斯抽采效果、消除煤体突出危险性的有效措施之一。但突出煤层多为高瓦斯低透气性松软煤层，钻割过程中煤或瓦斯喷出现象（简称“喷出”）时有发生，影响钻割施工进度，并在一定程度上制约了该技术的推广应用。本论文以完善钻割理论及装备、指导现场防喷出工作、保障钻割作业安全高效开展为出发点，围绕煤或瓦斯喷出这一中心点，采用理论分析、现场考察、数值模拟、装备及配套工艺研发、工业性试验等手段开展研究，主要成果如下：首先，结合理论积累及现场考察，从概论的角度探讨煤或瓦斯喷出现象。提出了喷出的概念，依据不同标准对其进行分类，并与普通喷孔对比，阐述了喷出的主要特点，还对喷出进行利弊分析，深入认识了喷出现象。其次，从能量的角度，运用综合作用假说，阐述了孔内突出过程；从煤浆液、瓦斯两相流的角度，，分别分析了钻杆静止和旋转时环形空间水力排渣流型及其特征参数。并基于如上理论，依次探讨了干式钻进及退钻割缝两个阶段的喷出发动机理，为深入研究防喷出方法奠定理论基础。再次，根据不同的射流压力和钻机钻速组合，提出了“强水快割”和“细水慢割”两种水力割缝方式，然后结合FLAC3D数值模拟和现场试验，分析了割缝方式、割缝阶段、煤层厚度等因素对喷出的影响。发现“强水快割”式水力割缝更易诱发喷出，并综合考察煤体消突和喷出可控，确定15MPa、160r/min为试验矿井最佳射流压力和钻机钻速。最后，研发了新型高效放水排渣、抽排瓦斯、孔口除尘三位一体防喷出装置及配套钻割新工艺，新工艺采用慢速干式钻进和“细水慢割式”退钻割缝，实用有效。现场试验结果表明：新型装置及工艺抽排瓦斯、落水降尘效果显著（巷道瓦斯浓度0.2%、平均除尘率90%），保证了钻割作业安全高效开展，提高了煤体消突效果。
[Abstract]:The conditions of gas storage in coal mines in our country are complex, the coal seams with low permeability are in the majority, and the effect of gas extraction by common boreholes is not ideal. Other pressure relief and antireflection measures are needed to assist. Theoretical analysis and engineering practice show that the integrated drilling and cutting hydraulic joint cutting technology is to improve the gas drainage effect at present. One of the effective measures to eliminate the danger of coal outburst is that most of the outburst coal seams are soft coal seams with high gas and low permeability, and the phenomenon of coal or gas ejection ("ejection") occurs frequently during drilling and cutting, which affects the progress of drilling and cutting construction. To some extent, it restricts the popularization and application of this technology. In this paper, to improve drilling theory and equipment, to guide the field anti-jet work, to ensure the safe and efficient development of drilling operations, around this central point of coal or gas ejection, theoretical analysis, on-site investigation, numerical simulation, The main results are as follows: (1) equipment and supporting technology research and development, industrial testing and other means to carry out the research, the main results are as follows:. First of all, combined with theoretical accumulation and field investigation, the phenomenon of coal or gas emission is discussed from the perspective of introduction. The concept of coal or gas emission is put forward and classified according to different standards. The advantages and disadvantages of ejection are also analyzed, and the phenomenon of ejection is deeply understood. Secondly, from the point of view of energy and comprehensive action hypothesis, the process of outburst in the hole and the two-phase flow of coal slurry and gas are expounded. The hydraulic slagging flow pattern and its characteristic parameters in annular space are analyzed respectively when the drill pipe is at rest and rotating. Based on the above theory, the ejection mechanism of dry-drilling and back-drilling seam is discussed in turn. It lays a theoretical foundation for further research on the method of preventing ejection. Thirdly, according to different combination of jet pressure and drilling speed, two hydraulic slit modes of "strong water quick cutting" and "fine water slow cutting" are put forward. Then, combined with FLAC3D numerical simulation and field test, the slit mode and slit stage are analyzed. The influence of coal seam thickness and other factors on the ejection. It is found that the "strong water quick cutting" hydraulic slit is more likely to induce ejection, and comprehensive investigation is made to control the outburst suppression and ejection of coal body, and the optimum jet pressure and drilling speed of drilling rig are determined to be 15 MPA / 160 r / min. Finally, a new type of high efficient water and slag discharge, gas drainage, orifice dust removal and a new matching drilling and cutting process are developed. The new technology adopts slow dry drilling and "fine water slow cutting" back cutting seam. Practical and effective. The field test results show that: the new device and technology drainage gas, falling water dust control effect is remarkable (gas concentration in roadway 0.2, average dust removal rate 90%, ensure the drilling operation safe and efficient, improve the coal body outburst suppression effect.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD712.7

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