MOE Key Lab of CBM Resources and Formation Process,China University of Mining and Technology School of
Electrical Engineering.Xian Jiaotong University

为解决高聚能电脉冲应力波煤储层致裂增渗新技术发展初期的诸多问题,采用电脉冲应力波加载试验与微区观测手段对鄂尔多斯盆地肥煤样品微裂隙的发生发展过程及其影响因素进行了研究。结果表明:在重复电脉冲应力波加载试验中,随冲击次数增多,微裂隙线密度增大,新生微裂隙的形成起源于冲击波产生的张剪性应力;煤体受力破坏过程大致分为3个阶段,冲击4次时煤体微裂隙网络基本形成,且没有明显的煤屑产生,为最佳冲击次数。煤体微裂隙网络主要发育在镜质组条带中,新生微裂隙优先从尺寸较大的原有结构性缺陷部位开始扩展,电脉冲应力波对煤体致裂增渗的效果十分明显,煤体中存在的原有结构缺陷是煤体微裂隙萌生的主要部位;煤岩条带类型及其组合方式,是制订煤储层增渗改造措施应考虑的重要地质因素。

In order to solve many problems occurred in the initial development period of the new coal reservoir fracturing and permeability improvement technology wit h high accumulated energy electric impulse stress wave,the electric impulse stress wave loading experiment and micro-location observation means were applied to the stu dy on the micro crack occurred development process of the fat coal sample from Ordos Basin and the influence factors.The results showed that in the repeated electric imp ulse stress loading experiment,with the impact number increased,the micro crack line density would be increased and the formation of the new generated micro crack woul d come from the shearing stress occurred by the impact wave.The stress failure process of coal could be divided to three stages generally.The micro crack network of coal would be basically formed when the coal was impacted fourthly,there would be no coal cuttings occurred obviously,so impacted fourthly was the best condition.The micro cr ack network of coal would be mainly developed in the vitrinite band, new generated micro cracks would have a priority to start the expansion in the large size original struct ural defects. The electric impulse stress wave would have obvious fracturing and permeability effect of the coal and the original structural defects existed in the coal would be main part to have the coal micro cracks.The coal and rick bands type and other combined mode would be the important geological factor considered to set up the coal r eservoir permeability improvement and reconstruction measures.

国家科技重大专项资助项目(2011ZX05034)；国家自然科学基金重点资助项目(U1361207)；