超声作用下煤岩细观损伤演化模型及增渗机理研究

发布时间：2018-06-01 10:30

本文选题：超声激励 + 细观尺度　；参考：《天然气地球科学》2016年01期

【摘要】：渗透率是指在一定压差下,多孔介质材料允许流体通过的能力,是描述多孔介质渗透性的重要物理参数。依据连续介质力学和唯象理论,在细观尺度上考虑了超声二次损伤对颗粒煤岩渗透率的重要影响,建立了超声激励过程中机械及热效应导致的有效应力和损伤量的理论模型。开展了不同气体压力下颗粒煤岩渗透率测定试验,拟合得到了渗透率与气体压力之间的经验公式,建立了煤岩气测渗透率、有效应力和二次损伤量间的关系模型。结果表明:超声作用能够有效提高颗粒煤岩体系的渗透率,有效应力的逐渐增大是超声增渗的主要原因;接触颗粒面元间损伤的增加和显著的热效应是渗透率增长率下降的主要影响因素。研究工作对煤层气增渗机理及优化开采具有重要的科学意义和工程实用价值。
[Abstract]:Permeability refers to the ability of porous media to allow fluid to pass through under a certain pressure difference. It is an important physical parameter to describe the permeability of porous media. According to the theory of continuum mechanics and phenomenology, the influence of secondary ultrasonic damage on the permeability of granular coal is considered on a meso-scale, and a theoretical model of the effective stress and damage caused by mechanical and thermal effects during ultrasonic excitation is established. The experiment of permeability measurement of granular coal and rock under different gas pressure was carried out, the empirical formula between permeability and gas pressure was obtained by fitting, and the relationship model between permeability, effective stress and secondary damage of coal and rock gas was established. The results show that ultrasonic can effectively improve the permeability of granular coal and rock system, and the increase of effective stress is the main reason of ultrasonic infiltration. The increase of damage between contact particles and the significant thermal effect are the main factors influencing the decrease of permeability growth rate. The research is of great scientific significance and practical value to the mechanism of coalbed methane infiltration and optimization of mining.
【作者单位】：辽宁工程技术大学力学与工程学院;东南大学工程力学系;北京市市政工程研究院;
【基金】：国家自然科学基金面上项目(编号:51374123);国家自然科学基金青年基金项目(编号:51004061) 2014年辽宁省优秀人才支持计划(编号:LJQ2014043)联合资助
【分类号】：TE37

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