基于突变理论的煤岩体损伤破裂研究

发布时间：2018-03-31 07:38

本文选题：脆性指数　切入点：折迭突变　出处：《东北石油大学》2017年硕士论文

【摘要】：随着科技的不断发展,能源利用率也在不断提高。我国煤层气产量在21世纪已经突破百亿立方米,这代表我国煤层气已经处于快速发展的时期。而提高煤层气产量的重要技术手段即为水力压裂。为了更加高效的开采煤层气,本文从煤岩体脆性以及煤岩体水力压裂释放能量的角度出发来研究煤岩体水力压裂与煤岩体脆性之间的内涵关系。本文主要研究内容如下:(1)本文首先对煤岩体受载损伤破裂的研究现状、岩体变形破坏的数值模拟、岩石声发射以及突变理论进行了国内外研究现状的调研。了解了国内外对于岩体受载损伤破裂及岩体突变的先进技术及理论。(2)本文介绍了多种岩体脆性表征的研究方法及理论,其中基于全应力应变曲线的脆性表征方法是应用比较广泛的。本文基于蒋东峰建立的基于损伤理论的脆性评价方法对岩体脆性指数进行研究,并对其进行评价试验,基于损伤理论的脆性评价结果较好。(3)根据RFPA2D-Basic版数值模拟软对12块煤岩岩样进行单轴压缩,可以得到不同煤岩体的应力应变曲线,根据单轴压缩得到的应力应变曲线以及上文的岩体脆性指数,得到不同岩体的脆性。通过研究不同脆性岩体的声发射信号及能量,研究煤岩体脆性与声发射之间关系规律。(4)结合脆性指数与突变理论建立煤岩体损伤折迭突变模型,并根据煤岩体损伤折迭突变模型建立煤岩体损伤能量释放量模型。通过RFPA2D-Flow版数值模拟软件,对12块煤岩岩样进行水力压裂数值模拟,根据不同煤岩体脆性的水力压裂模拟结果,可以得到:岩体脆性越大,煤岩体水力压裂越容易形成复杂缝网。分析层理以及围压对煤岩体水力压裂的影响,研究结果说明层理角度越大,围压越小,煤岩体脆性越大,煤岩体水力压裂越易形成较多的分支缝及复杂缝网。
[Abstract]:With the development of science and technology, energy efficiency is also increasing.The production of coalbed methane in China has exceeded 10 billion cubic meters in the 21st century, which means that the coal bed methane in China has been in a period of rapid development.Hydraulic fracturing is an important technical means to improve CBM production.In order to exploit coalbed methane more efficiently, this paper studies the intension relation between coal-rock hydraulic fracturing and coal-rock brittleness from the angle of coal rock mass brittleness and coal rock mass hydraulic fracturing releasing energy.The main contents of this paper are as follows: (1) in this paper, the current situation of research on the damage and fracture of coal and rock mass under load, numerical simulation of deformation and failure of rock mass, acoustic emission of rock and the theory of sudden change have been investigated at home and abroad.The advanced technology and theory of rock mass damage and fracture and rock mass catastrophe at home and abroad are understood. In this paper, several research methods and theories of rock mass brittleness characterization are introduced.The brittleness characterization method based on the full stress-strain curve is widely used.In this paper, the brittleness index of rock mass is studied based on damage theory established by Jiang Dongfeng.The brittleness evaluation results based on damage theory are good. (3) according to the numerical simulation of RFPA2D-Basic version, 12 samples of coal rock can be subjected to uniaxial compression, and the stress-strain curves of different coal and rock masses can be obtained.According to the stress-strain curve obtained by uniaxial compression and the brittleness exponent of rock mass mentioned above, the brittleness of different rock masses is obtained.By studying the acoustic emission signal and energy of different brittle rock mass, the relationship between coal and rock mass brittleness and acoustic emission is studied. (4) combined with brittleness exponent and catastrophe theory, the damage and folding catastrophe model of coal and rock mass is established.The energy release model of coal and rock damage is established according to the model of coal and rock mass damage.According to the hydraulic fracturing simulation results of different coal and rock brittleness, it can be concluded that the larger the rock mass brittleness, the easier it is to form a complex fracture network for hydraulic fracturing of coal and rock mass through the numerical simulation software of RFPA2D-Flow.The effects of bedding and confining pressure on hydraulic fracturing of coal and rock mass are analyzed. The results show that the greater the bedding angle, the smaller the confining pressure, the greater the brittleness of coal and rock mass, and the easier it is to form more branching fractures and complex fracture nets.
【学位授予单位】：东北石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD311

【相似文献】