综采面煤层定向水压裂缝扩展规律研究

发布时间：2018-04-17 16:49

本文选题：裂缝扩展 + 定向水力压裂　；参考：《西安科技大学》2015年硕士论文

【摘要】：论文以陕西省红石岩煤矿开采条件为背景,针对综采工作面煤层定向水力压裂问题,通过岩石力学实验、理论分析、数值计算和现场试验观测等综合手段,研究了坚硬煤层定向水力压裂超前预裂,增加和扩展综采面煤层裂隙提高块煤率的机理。分析了影响综采面煤层裂缝扩展因素及煤体物理力学参数和定向压裂工艺参数;分析了定向切槽钻孔和未切槽钻孔,以及在不同切槽钻孔参数下煤层的应力分布和裂缝扩展的演化过程。确定了红石岩煤矿综采面定向水力压裂技术与工艺参数。现场应用结果证明了预裂工艺参数的有效性。本文首先对影响综采面煤层裂缝扩展的煤体物理力学参数进行实验测定分析,以及对采用定向水力压裂技术的预裂器主要参数进行了分析研究。得到了煤岩体力学参数与含水率之间的关系,确定了工艺参数压力的范围,为压裂设备的开发提供依据;确定了预裂器主要参数,为施工工艺参数的选择提供了依据。然后通过分析红石岩煤矿煤层赋存的地质条件,运用RFPA-Flow模拟软件分析了定向压裂切槽钻孔与未切槽钻孔,以及不同参数切槽钻孔在高压注水时应力场的变化规律以及煤层中裂缝的演化过程,总结煤层在定向水力压裂条件下的裂缝扩展规律。定向水压裂缝在一定范围内可控,能够形成比未切槽钻孔较多的裂缝群,在采煤机扰动和煤块自重作用下,就会形成较多块煤,提高了块煤率。最后,在红石岩煤矿12406综采工作面进行定向水力压裂技术的应用,对压裂工艺参数进行现场监测并优化。试验结果证明,采用定向水力压裂技术后,块煤率有了较大的提高,切槽预先释放了综采面采动集中应力,释放了煤层中瓦斯,预防了工作面支架冲击灾害。采煤机割煤速度也提高,材料消耗率下降,原煤产量增加,工作面粉尘降低,对综采工作面高效开采和安全生产具有重要意义。
[Abstract]:Based on the mining conditions of Hongshiyan coal mine in Shaanxi Province, aiming at the problem of directional hydraulic fracturing in coal seam of fully mechanized coal face, the comprehensive means of rock mechanics experiment, theoretical analysis, numerical calculation and field test observation are adopted in this paper.This paper studies the mechanism of directional hydraulic fracturing in hard coal seam to increase and extend the fracture of coal seam in fully mechanized coal face to increase the coal mass rate.The factors affecting the crack propagation of coal seam in fully mechanized coal face, the physical and mechanical parameters of coal body and the parameters of directional fracturing process are analyzed, and the directional and uncut grooves drilling are analyzed.And the evolution process of stress distribution and crack propagation of coal seam under different drilling parameters.The directional hydraulic fracturing technology and technical parameters of fully mechanized face of Hongshiyan Coal Mine are determined.The field application results show that the presplitting process parameters are effective.In this paper, the physical and mechanical parameters of coal body which affect the crack propagation in coal seam of fully mechanized coal face are measured and analyzed experimentally, and the main parameters of prefracturing device using directional hydraulic fracturing technique are analyzed and studied.The relationship between mechanical parameters of coal and rock mass and water content is obtained, the range of pressure of process parameters is determined, which provides the basis for the development of fracturing equipment, and the main parameters of pre-cracking apparatus are determined, which provides a basis for the selection of construction process parameters.Then, by analyzing the geological conditions of coal seam occurrence in Hongshiyan coal mine, and using RFPA-Flow simulation software, the paper analyzes the directional fracturing slot drilling and the uncut groove drilling.The variation law of stress field and the evolution process of fracture in coal seam under high pressure water injection with different parameters are summarized, and the fracture propagation law of coal seam under directional hydraulic fracturing is summarized.The directional hydraulic fracture can be controlled within a certain range and can form more fracture groups than the uncut grooves. Under the disturbance of the shearer and the self-weight of the coal block, more blocks of coal will be formed and the rate of block coal will be increased.Finally, the application of directional hydraulic fracturing technology in 12406 fully mechanized face of Hongshiyan Coal Mine is carried out, and the parameters of fracturing process are monitored and optimized.The test results show that the block coal rate has been greatly improved by adopting the directional hydraulic fracturing technology, the cutting groove has released the mining concentration stress in the fully mechanized face in advance, the gas in the coal seam has been released, and the impact disaster of the support in the working face has been prevented.The coal cutting speed of shearer also increases, the material consumption rate decreases, the raw coal output increases, and the working face dust decreases, which is of great significance to the high efficiency mining and safe production of fully mechanized coal mining face.
【学位授予单位】：西安科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TD32

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