Evolution of rock fracture permeability in coupled processes with variable temperatures
JIA Chun-lan1, ZHU Kai2
1. Xinjiang Survey and Design Institute for Water Resources and Hydropower, Urumqi 830000, China; 2. College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China
Abstract:The projects in deep rock are under complex geological environment of high stress, high water pressure, high heat, etc. These factors may have important influences on the permeability in fractured rock and further on the safety and productivity of deep rock projects. Flow-through tests on an artificial fracture in limestone are conducted at 25℃~90℃. The effects of different temperatures on the evolution of permeability in fractured rock are studied. The results show that at the initial stage of heating, the flow has a peak under constant effective stress. It decreases slowly until one steady count at constant temperature at last. The fracture permeability declines monotonically with the increasing temperature under constant effective stress. Faster speeds of fracture closure at the initial stage, shorter time required for stabilization and smaller aperture at the final equilibrium under higher temperatures can also be observed. The solubility speed and dissolved mineral matter of limestone increase with the increasing temperatures.
贾春兰, 朱凯. 复合温度条件下石灰岩多场耦合裂隙渗透侵蚀试验研究[J]. 岩土工程学报, 2015, 37(7): 1307-1312.
JIA Chun-lan, ZHU Kai. Evolution of rock fracture permeability in coupled processes with variable temperatures. Chinese J. Geot. Eng., 2015, 37(7): 1307-1312.
[1] FENG X, LIU J, JING L. Research and application on coupled t-h-m-c processes of geological media in china-a review[J]. Elsevier Geo-Engineering Book Series, 2004, 2: 37-48. [2] POLAK A, ELSWORTH D, YASUHARA H, et al. Permeability reduction of a natural fracture under net dissolution by hydrothermal fluids[J]. Geophysical Research Letters, 2003, 30(20). [3] YASUHARA H, KINOSHITA N, OHFUJI H, et al. Temporal alteration of fracture permeability in granite under hydrothermal conditions and its interpretation by coupled chemo-mechanical model[J]. Applied Geochemistry, 2011, 26(12): 2074-2088. [4] TARON J, ELSWORTH D. Thermal-hydrologic-mechanical- chemical processes in the evolution of engineered geothermal reservoirs[J]. International Journal of Rock Mechanics and Mining Sciences, 2009, 46(5): 855-864. [5] 贺玉龙, 杨立中. 温度和有效应力对砂岩渗透率的影响机理研究[J]. 岩石力学与工程学报, 2005, 24(14): 2420-2427. (HE Yu-long, YANG Li-zhong. Mechanism of effects of temperature and effective stress on permeability of sandstone[J]. Chinese Journal of Rock Mechanics and Engineering, 2005, 24(14): 2420-2427. (in Chinese)) [6] 张玉军, 张维庆. 三维双重孔隙-裂隙介质热-水-应力-迁移耦合模型及其有限元分析[J]. 中国科学 (技术科学), 2010, 40(12): 1426-1436. (ZHANG Yu-Jun, ZHANG Wei-Qing. 3D thermo-hydro-mechanical-migratory coupling model and femanalyses for dual-porosity medium[J]. Sciences China (Technology Sciences), 2010, 40(12): 1426-1436. (in Chinese)) [7] GANGI A F. Variation of whole and fractured porous rock permeability with confining pressure[C]// Prestened at the First International Symposium on Induced Seismicity(ISIS). Banff, 1975. [8] 刘亚晨. 裂隙岩体介质 THM 耦合问题中的渗透特性研究[J]. 地质灾害与环境保护, 2004, 15(1): 80-84. (LIU Ya-chen. Study on the permeable behavior of coupled thermo-hydro-mechanical problem in fracture rock mass media[J]. Journal of Geological Hazards and Environment Preservation, 2004, 15(1): 80-84. (in Chinese)) [9] YASUHARA H, ELSWORTH D. Compaction of a rock fracture moderated by competing roles of stress corrosion and pressure solution[J]. Pure and Applied Geophysics, 2008, 165(7): 1289-1306. [10] POLAK A, YASUHARA H, ELSWORTH D, et al. The evolution of permeability in natural fractures-the competing roles of pressure solution and free-face dissolution[J]. Elsevier Geo-Engineering Book Series, 2004, 2: 721-726.