活性炭测氡法监测煤岩水力压裂裂缝的尝试

发布时间：2018-05-08 04:45

本文选题：活性炭测氡法 + 煤岩　；参考：《太原理工大学》2017年硕士论文

【摘要】：在煤层气开发过程中,对于低渗透煤层,水力压裂工艺是提高产气量的重要手段,而压裂所产生裂缝的形态和规模是井网部署的重要参考依据。因此,需对煤岩压裂裂缝的长度、宽度、高度、方位角和压裂规模等进行深入研究。目前,常用数值模拟方法来模拟裂缝的形态,而压裂裂缝监测技术属微地震法较为成熟,但该方法要有质量较高的观测井。因此,不借助观测井监测压裂裂缝的活性炭测氡方法是值得研究的。本文在搜集了大量文献的基础上,对活性炭测氡技术的研究现状进行了综述,分析了岩石压裂对氡气析出的影响,探讨了地下煤(岩)层压裂可在地面形成氡异常的因素,并就采用适于进行监测的活性炭测氡法给出了分析与阐述,认为活性炭测氡法在地面监测煤(岩)层压裂裂缝方法是可行的。活性炭测氡监测的现场试验,是结合在柿庄北区块对12个煤层气井压裂的实际情况进行的。本文通过阐释试验区的地层岩性、煤层分布、煤岩力学性质、地应力状况和煤层气井的压裂施工情况。在煤层气井压裂施工前进行了整个试验区的活性炭测氡监测工作,给出试验区氡气背景值的分布,并在压裂施工后又进行了3次监测,分别得到了氡异常变化的平面的分布。通过分析并对比四次监测工作得到的氡异常范围以及由数值模拟得到的压裂裂缝模拟半长,对本次活性炭测氡方法在监测压裂裂缝方面的效果做出了初步的评价。本次尝试的结果表明:活性炭测氡法能够监测到由煤岩压裂引起的氡异常,但没能准确监测到压裂裂缝的长度信息。
[Abstract]:In the process of coalbed methane development, hydraulic fracturing technology is an important means to increase gas production for low permeability coal seams, and the shape and scale of fractures produced by fracturing are important reference basis for well pattern deployment. Therefore, the length, width, height, azimuth and fracturing scale of fracture in coal and rock fracturing need to be deeply studied. At present, numerical simulation is commonly used to simulate fracture morphology, and fracture monitoring technology is more mature, but this method should have high quality observation wells. Therefore, the method of radon measurement by activated carbon without using observation wells to monitor fracturing fractures is worth studying. On the basis of collecting a large number of documents, this paper summarizes the research status of radon measurement technology by activated carbon, analyzes the influence of rock fracturing on radon gas release, and discusses the factors of radon anomaly in underground coal (rock) layer fracturing. The radon measurement method with activated carbon which is suitable for monitoring is analyzed and expounded. It is considered that it is feasible to monitor fracturing fractures in coal (rock) layers by radon measurement with activated carbon on the ground. The field test of radon measurement by activated carbon was carried out in Shizhuangbei block, and the fracturing of 12 coalbed gas wells was carried out. In this paper, the formation and lithology, the distribution of coal seam, the mechanical properties of coal and rock, the condition of in-situ stress and the fracturing operation of coalbed methane well are explained. The radon monitoring work of activated carbon in the whole test area was carried out before the coalbed gas well fracturing, the distribution of radon background value was given, and the radon abnormal plane distribution was obtained after fracturing operation. By analyzing and comparing the radon anomaly range obtained from four monitoring work and the half length of fracturing fracture simulation obtained by numerical simulation, this paper makes a preliminary evaluation on the effect of the radon measurement method with activated carbon in monitoring fracturing fracture. The results show that the radon anomaly caused by coal and rock fracturing can be detected by activated carbon radon measurement method, but the length information of fracturing fracture can not be accurately monitored.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE377

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