【作者】 郝志勇；

【导师】 林柏泉；

【作者基本信息】 中国矿业大学 ， 安全技术及工程， 2010， 博士

【摘要】 钻孔抽采是煤矿瓦斯治理的基础技术手段,应用范围广泛。而打好钻孔后一般都要求对钻孔进行密封,钻孔密封是保持孔底负压或正压的关键因素。封孔质量的好坏直接影响各类钻孔作用的发挥。而我国煤矿各类钻孔的封孔质量均不容乐观,迫切需要开展钻孔密封材料、技术及装备的研究。为了遏制瓦斯突出、瓦斯爆炸等重大事故的发生,提高钻孔抽放效率、煤与瓦斯突出煤层消突速率、减少钻孔数量,节约生产成本,开展复合材料在钻孔密封技术中的应用研究具有十分重要的现实意义。本文首先通过对钻孔周围条件的简化,分析了孔周围应力场和裂隙场的分布情况。理论推导得出了钻孔周围破碎区和塑性区半径的表达公式。理论分析结合数值模拟结果认为:从钻孔的中心向外延伸,钻孔周围可分为四个区域,即破裂区、塑性区、弹性区、原岩应力区,钻孔周围存在一个应力大、渗透率小的约束环。钻孔周围岩体内的裂隙密封就是注入的密封浆液在外加压力或自身膨胀压力下扩散进入填充钻孔周边塑性区的范围,使得钻孔到塑性区范围内的渗透率和力学状态发生改变。其次,在渗透注浆球形扩散和柱面扩散理论的基础上,根据渗透率与应力状态和注浆参数之间的函数关系,推导出流体密封后钻孔围岩渗流和应力状态变化的理论模型,描述了钻孔周围岩体渗透率和钻孔周围岩体应力应变与各注浆参数之间的关系。第三,依据对钻孔微裂隙进行密封的要求,开发出了水泥基聚合物复合密封材料,应用复合材料的界面理论、水泥的膨胀机理、微胶囊化技术、扩散控制的化学反应原理、溶胶相变过程等方面,阐述了水泥基聚合物复合密封材料的反应机理。第四,根据钻孔现场应用对密封材料的要求,确定了材料原料的种类和实验工艺流程。实验研究了聚合物对材料致密性的影响、膨胀剂对材料膨胀性能的影响、囊壁质量比对材料膨胀速率的影响、溶胶相变时间的影响因素等,确定了原料的种类和基本的用量。采用正交实验,得到了三种合适的水泥基聚合物复合钻孔密封材料——PD系列,膨胀性能测试显示,三者的膨胀系数分别为1.29,1.31,1.35。分别对PD-I、PD-III进行了密封负压钻孔性能测试和密封正压钻孔性能测试,测试结果表明:针对负压抽采钻孔和正压压裂钻孔密封性能要求,所开发材料的密封性能良好,密封效果均要优于聚氨酯材料。对PD材料和聚氨酯材料的细观图像进行观测及分析,解释了PD材料更加致密的原因。第五,将配置好PD材料作为真实流体,研究了其在管路中流动经过阀门时的运动规律。结果认为:密封浆液流动需要驱动设备具有一定的压力,用以克服流动阻力。研制了有液压助力系统往复式柱塞泵系列设备,根据不同的动力来源分为:手动液压注浆泵、风动液压注浆泵、双动力注浆泵和配套的气动搅拌机。最后,根据密封材料和注浆设备的性能,开发了压塞-注浆封孔工艺。从材料到结构上,自行设计密封装置的关键部件-堵浆塞。在此基础上,在平煤四矿进行了PD-II密封本煤层钻孔和迎面斜交钻孔的工作,在郑煤崔庙矿采用PD-I和PD-III协同密封穿层钻孔进行条带消突的工作,对相关参数进行了测试、分析。通过以上研究,在理论上阐述了钻孔流体密封的实质,推导出流体密封后钻孔围岩渗流和应力状态变化的理论模型,技术上开发了用于钻孔密封的水泥基聚合物复合钻孔密封材料和“压塞—注浆”封孔工艺,装备上研制了用于将密封材料输送到钻孔密封段的注浆设备,实际应用反映了该系统封孔技术具有较大的优越性。课题研究期间,作者公开发表学术论文6篇,其中EI检索2篇;取得或申请受理专利8项,其中发明专利4项;获得省部级科研二等奖1项,排名第七。更多还原

【Abstract】 As a basic technical means for controlling gas, sealing has extensive application ranges in mine areas. In our country, however, the sealing quality of various drillings is unsatisfactory, which needs to research on sealing material, technology and equipment. To improve utilization ratio of sealing, accelerate elimination outburst rate of coal seam, reduce number of drilling and save production cost, the researches on sealing drilling with composite have very important realistic significance for the containment of serious accidents, such as gas outburst and gas explosion.The main results in this thesis are as follows:Firstly, we analyzed the distribution of stress field and fracture field around the drilling, deduced the expression formulas of fractured zone and plastic zone that around the drilling. Some conclusions were obtained from theoretical analysis and numerical simulation. Sealing rock fracture was formed around the drilling, based on the injected sealing grout spreads and fills the plastic zone by adscititious pressure or swelling pressure itself, which making the permeability and mechanical state change in the drilling to the plastic zone.Secondly, according to the permeation grouting theory with the spherical diffusion and cylindrical diffusion, the theoretical model of seepage and stress distribution around the drilling after sealing with fluid was deduced. The model describes the relations between permeability, stress in rock around the boreholes and parameters of different slurry.Thirdly, requiring by for micro-fissure sealing, the cement-based polymer composite was developed. . Moreover, the reaction mechanism of the cement-based polymer composite is expounded through researching on the interface theory of composite, expansion mechanism of cement, micro-encapsulation technology, reaction principle of controlling the spread and the process of sol transition.Fourthly, the types of target material and technological processes of experiments were established based on requirement of sealing material. The types and quantity of the raw material are determined owing to above researches. After the orthogonal experiments, three cement-based polymers composite were obtained - PD materials. The value of expansion coefficient about three materials is 1.29, 1.31, and 1.35, respectively. The tests of sealing negative pressure drilling character for PD-I material and tests of sealing high pressure drilling character for PD-III material saw a conclusion: The sealing performance of PD was better than polyurethane. The reason is explained that why the PD is denser, by analyzing and observing micro- structure of PD and polyurethane.In addition, the analysis indicates that the equipment should have some stress to overcome resistance of the fluid flowing. Furthermore, we developed the reciprocating plunger pumps with hydraulic booster system, including manual hydraulic injection pump, pneumatic hydraulic injection pump, double dynamical injection pump and the matched pneumatic mixer.Finally, according to the performances of sealing materials and grouting equipments, a kind of tamponade - grouting sealing process was developed and its key part - plugging slurry plug was designed. Meanwhile, we popularized the technology in Ping Dingshan mine areas with PD-II and used PD-III in Cui Miao mine, evaluated and analyzed the interrelated parameters, simultaneously.From the researches above, the essence of sealing drilling was obtained in theory aspect, the theoretical model of seepage and stress distribution around the drilling after sealing with fluid was deduced, while the cement-based polymer composite and the tamponade - grouting sealing process was developed. Meanwhile, the equipment to transport sealing material into drilling developed, too. The studies show that the new hole sealing technology has more superiority in the practical applications and the coming future.During the research, the authors published 6 papers, in which 2 were Search by EI; obtain or apply for the processing of 8 patents, 4 of which are invention patents; and won the second prize of a ministerial-level scientific research, ranking seventh.更多还原