Author:
Liu Xiaolei,Wei Jianping,Wei Guoying,Wu Caifang,Liu Cao,Ni Xiaoming
Abstract
AbstractThe variations of strain and permeability of coal were systematically studied through the physical simulation of N2 and water injection. The effects of fluid adsorption capacity and initial permeability on strain, permeability and the dominant effect of pore pressure were discussed. The adsorption strain and strain rate of coal during water injection are significantly higher than those during N2 injection. An edge of free adsorption exists in the early phase of N2 and water injection, which is related to fluid saturation. Within this boundary, the strain rate and pore pressure are independent. Moreover, the injection time of initial stage accounts for about 20% of the total injection time, but the strain accounts for 70% of the total strain. For water injection, this boundary is about half of water saturation of coal. Besides, the influence of pore pressure on permeability is complex, which is controlled by adsorption capacity and initial permeability of coal. When the initial permeability is large enough, the effect of adsorption strain on permeability is relatively weak, and the promoting effect of pore pressure on fluid migration is dominant. Therefore, the permeability increases with increasing pore pressure. When the initial permeability is relatively low, the pore pressure may have a dominant role in promoting fluid migration for the fluid with weak adsorption capacity. However, for the fluid with strong adsorption capacity, the adsorption strain caused by pore pressure may play a leading role, and the permeability reduces first and then ascends with increasing pore pressure.
Funder
National Natural Science Foundation of China
Key Science and Technology Program of Henan Province
China Postdoctoral Science Foundation
State Key Laboratory Cultivation Base for Gas Geology and Gas Control
Key Scientific Research Project of Colleges and Universities in Henan Province
Doctor foundation of Henan Polytechnic University
Publisher
Springer Science and Business Media LLC
Subject
Energy Engineering and Power Technology,Geotechnical Engineering and Engineering Geology
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献