(1. State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;2. School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou,Jiangsu 221116,China;3. School of Architecture and Civil Engineering,Nantong University,Nantong,Jiangsu 226019,China)
Abstract:Temperature is one of the important factors influencing the physical properties of rock. In order to obtain the effect of temperature on the pore size distribution in rock material,the mercury intrusion porosimetry was adopted to test the pore characteristics of granite samples after high temperature treatment of 25 ℃–1 200 ℃. The fractal structure and model of pore size distribution under different high temperatures were then studied. The results showed that the rock porosity increased exponentially with the rising heating temperature and 500 ℃–800 ℃ was a threshold temperature interval. The porosity increased only 50% below 500 ℃ and about 3 to 5 times from 500 ℃ to 1 200 ℃. Most of the new pores and cracks induced by the high temperature are meso pores with the average diameter between 1 μm and 10 μm. The meso pores account for about 15% when the heat temperature is lower than 500 ℃,and then increases steadily and reaches 28.24% at 800 ℃,more than 40% over 1 000 ℃,and its volume increases by 11.8 times. The pore size distribution of rock under different temperatures exhibits a good statistical fractal feature with the pore fractal dimension between 2.99 and 3. With the rising of the temperature,the fractal dimension decreases more and more,which shows that the uniformity of pore distribution is raised. The model by ZHANG Jiru and TAO Gaoliang are proved better than the one of Friesen model based on ideal Menger sponge in predicting the rock porosity of different pore size.
张志镇1,2,高 峰1,2,高亚楠1,2,徐小丽1,2,3,侯 鹏1,2,滕 腾1,2,尚晓吉1,2. 高温影响下花岗岩孔径分布的分形结构及模型[J]. 岩石力学与工程学报, 2016, 35(12): 2426-2438.
ZHANG Zhizhen1,2,GAO Feng1,2,GAO Yanan1,2,XU Xiaoli1,2,3,HOU Peng1,2,TENG Teng1,2,SHANG Xiaoji1,2. Fractal structure and model of pore size distribution of granite under high temperatures. , 2016, 35(12): 2426-2438.
[1] HARRISON J P,HUDSON J A. Engineering rock mechanics:an introduction to the principles[M]. Netherland:Elsevier Science Ltd.,2000:5–20
[2] 杨永明,鞠 杨,刘红彬,等. 孔隙结构特征及其对岩石力学性能的影响[J]. 岩石力学与工程学报,2009,28(10):2 031–2 038. (YANG Yongming,JU Yang,LIU Hongbing,et al. Influence of porous structure properties on mechanical performances of rock[J]. Chinese Journal of Rock Mechanics and Engineering,2009,28(10):2 031–2 038.(in Chinese))
[3] AL-HARTHI A A,AL-AMRI R M,SHEHATA W M. The porosity and engineering properties of vesicular basalt in Saudi Arabia[J]. Engineering Geology,1999,54(3/4):313–320.
[4] GRUESCU C,GIRAUD A,HOMAND F,et al. Effective thermal conductivity of partially saturated porous rocks[J]. International Journal of Solids and Structures,2007,44(3/4):811–833.
[5] ZHANG Z T,ZHANG R,XIE H P,et al. The relationships among stress,effective porosity and permeability of coal considering the distribution of natural fractures:theoretical and experimental analyses[J]. Environmental Earth Sciences,2015,73(10):5 997–6 007.
[6] 刘堂晏,汤天知,杜环虹,等. 考虑储层孔隙结构的岩石导电机制研究[J]. 地球物理学报,2013,56(8):2 818–2 826.(LIU Tangyan,TANG Tianzhi,DU Huanhon,et al. Study of rock conductive mechanism based on pore structure[J]. Chinese Journal of Geophysics,2013,56(8):2 818–2 826.(in Chinese))
[7] 侯宇光,何 生,易积正,等. 页岩孔隙结构对甲烷吸附能力的影响[J]. 石油勘探与开发,2014,41(2):248–256.(HOU Yuguang,HE Sheng,YI Jizheng,et al. Effect of pore structure on methane sorption capacity of shales[J]. Petroleum Exploration and Development, 2014,41(2):248–256.(in Chinese))
[8] UGUR I,SENGUN N,DEMIRDAG S,et al. Analysis of the alterations in porosity features of some natural stones due to thermal effect[J]. Ultrasonics,2014,54(5):1 332–1 336.
[9] 杨 彧,陈进宇,杨晓松. 汶川地震破裂带断层岩纵波速度与孔隙度关系的实验研究[J]. 地球物理学报,2014,57(6):1 883–1 890. (YANG Yu,CHEN Jinyu,YANG Xiaosong. Experimental studies on relationship between P-wave velocity and porosity of fault rocks from the rupture of the 2008 Wenchuan earthquake[J]. Chinese Journal of Geophysics,2014,57(6):1 883–1 890.(in Chinese))
[10] NIE B S,LIU X F,YANG L L,et al. Pore structure characterization of different rank coals using gas adsorption and scanning electron microscopy[J]. Fuel,2015,158:908–917.
[11] JU Y,YANG Y M,SONG Z D,et al. A statistical model for porous structure of rocks[J]. Science in China:Series E,2008,51(11):2 040–2 058.
[12] 郝乐伟,王 琪,唐 俊. 储层岩石微观孔隙结构研究方法与理论综述[J]. 岩性油气藏,2013,25(5):123–128.(HAO Lewei,WANG Qi,TANG Jun. Research progress of reservoir microscopic pore structure[J]. Lithologic Reservoirs,2013,25(5):123–128.(in Chinese))
[13] THOMEER J H M. Introduction of a pore geometrical factor defined by the capillary pressure curve[J]. Journal of Petroleum Technology,1960,12(3):73–77.
[14] WARDLAW N C,TAYLOR R P. Mercury capillary pressure curves and the interpretation of pore structure and capillary behavior in reservoir rocks[J]. Bulletin of Canadian Petroleum Geology,1976,24(2):225–262.
[15] 承秋泉,陈红宇,范 明,等. 盖层全孔隙结构测定方法[J]. 石油实验地质,2006,28(6):604–608.(CHENG Qiuquan,CHEN Hongyu,FAN Ming,et al. Determination of the total pore texture of caprock[J]. Petroleum Geology and Experiment,2006,28(6):604–608.(in Chinese))
[16] 马文国,王 影,海明月,等. 压汞法研究岩心孔隙结构特征[J]. 实验技术与管理,2013,30(1):66–69.(MA Wenguo,WANG Ying,HAI Mingyue,et al. Research of pore structure characteristics of cores based on mercury penetration experiments[J]. Experimental Technology and Management,2013,30(1):66–69.(in Chinese))
[17] GAO Z,HU Q. Estimating permeability using median pore-throat radius obtained from mercury intrusion porasimetry[J]. Journal of Geophysics Engineering,2013,10(2):025014.
[18] GAO Z,HU Q,LIANG H. Gas diffusivity in porous media:Determination by mercury intrusion porosimetry and correlation to porosity and permeability[J]. Journal of Porous Media,2013,16(7):607–617.
[19] SHIN H S,KIM K Y,PANDE G N. On computation of strain-dependent permeability of rocks and rock-like porous media[J]. International Journal of Numerical and Analytical Methods in Geomechanics, 2015,39(8):821–832.
[20] ZHENG H,FENG X T,PAN P Z. Experimental investigation of sandstone properties under CO2-NaCl solution-rock interactions[J]. International Journal of Greenhouse Gas Control,2015,37:451–470.
[21] 马新仿,张士诚,郎兆新. 分形理论在岩石孔隙结构研究中的应用[J]. 岩石力学与工程学报,2003,22(增1):2 164–2 167.(MA Xinfang,ZHANG Shicheng,LANG Zhaoxin. Application of fractal theory to pore structure research[J]. Chinese Journal of Rock Mechanics and Engineering,2003,22(Supp.1):2 164–2 167.(in Chinese))
[22] 杨庆红,谭 吕,蔡建超,等. 储层微观非均质性定量表征的分形模型[J]. 地球物理学进展,2012,27(2):603–609.(YANG Qinhong,TAN Lu,CAI Jianchao,et al. Fractal models for quantitative cahracterization of the reservoir microscopic heterogeneity[J]. Progress in Geophysics,2012,27(2):603–609.(in Chinese))
[23] LAI J,WANG G W. Fractal analysis of tight gas sandstones using high-pressure mercury intrusion techniques[J]. Journal of Natural Gas Science and Engineering,2015,24:185–196.
[24] SUN W J,FENG Y Y,JIANG C F,et al. Fractal characterization and methane adsorption features of coal particles taken from shallow and deep coalmine layers[J]. Fuel,2015,155:7–13.
[25] GIRI A,TARAFDAR S,GOUZE P,et al. Multifractal analysis of the pore space of real and simulated sedimentary rocks[J]. Geophysical Journal International,2015,200(2):1 106–1 115.
[26] ZHANG Z Y,WELLER A. Fractal dimension of pore-space geometry of an Eocene sandstone formation[J]. Geophysics,2014,79(6):D377–D387.
[27] 陶高梁,张季如. 表征孔隙及颗粒体积与尺度分布的两类岩土体分形模型[J]. 科学通报,2009,54(6):838–846.(TAO Gaoliang,ZHANG Jiru. Two categories of fractal models of rock and soil expressing volume and size-distribution of pores and grains[J]. Chinese Science Bulletin,2009,54(6):838–846.(in Chinese))
[28] ZHANG J R,TAO G L,HUANG L,et al. Porosity models for determining the pore-size distribution of rocks and soils and their applications[J]. Chinese Science Bulletin,2010,55(34):3 960–3 970.
[29] 徐小丽,高 峰,沈晓明,等. 高温后花岗岩力学性质及微孔隙结构特征研究[J]. 岩土力学,2010,31(6):1 752–1 758.(XU Xiaoli,GAO Feng,SHEN Xiaoming,et al. Research on mechanical characteristics and micropore structure of granite under high-temperature[J]. Rock and Soil Mechanics,2010,31(6):1 752–1 758.(in Chinese))
[30] 杨永明,鞠 杨,陈佳亮,等. 温度作用对孔隙岩石介质力学性能的影响[J]. 岩土工程学报,2013,35(5):856–864.(YANG Yongming,JU Yang,CHEN Jialiang,et al. Mechanical properties of porous rock media subjected to temperature effect[J]. Chinese Journal of Geotechnical Engineering,2013,35(5):856–864.(in Chinese))
[31] 刘向君,高 涵,梁利喜. 温度围压对低渗透砂岩孔隙度和渗透率的影响研究[J]. 岩石力学与工程学报,2011,30(增2):3 771–3 778. (LIU Xiangjun,GAO Han,LIANG Lixi. Study of temperature and confining pressure effects on porosity and permeability in low permeability sandstone[J]. Chinese Journal of Rock Mechanics and Engineering,2011,30(Supp.2):3 771–3 778.(in Chinese))
[32] 于艳梅,胡耀青,梁卫国,等. 应用CT技术研究瘦煤在不同温度下孔隙变化特征[J]. 地球物理学报,2012,55(2):637–644.(YU Yanmei,HU Yaoqing,LIANG Weiguo,et al. Study on pore characteristics of lean coal at different temperature by CT technology[J]. Chinese Journal of Geophysics,2012,55(2):637–644.(in Chinese))
[33] 陈向军,刘 军,王 林,等. 不同变质程度煤的孔径分布及其对吸附常数的影响[J]. 煤炭学报,2013,38(2):294–301.(CHEN Xiangjun,LIU Jun,WANG Lin,et al. Influence of pore size distribution of different metamorphic grade of coal on adsorption constant[J]. Journal of China Coal Society,2013,38(2):294–301.(in Chinese))
[34] 吴恩江,韩宝平,王桂梁,等. 山东兖州煤矿区侏罗纪红层孔隙测试及其影响因素分析[J]. 高校地质学报,2005,11(3):442–452. (WU Enjiang,HAN Baoping,WANG Guiliang,et al. Pore structure test of Jurassic red-bed in Yanzhou mining area,Shandong province,and its affecting factors[J]. Geological Journal of China Universities,2005,11(3):442–452.(in Chinese))
[35] 孙君秀,谢亦汉,张友南. 华北太古宙长英质岩石的地震波速度及其在地壳中的位置[J]. 地震学报,2000,22(6):622–631.(SUN Junxiu,XIE Yihan,ZHANG Younan. Seismic wave velocity of archeozoic felsic rocks from North China and its existing location in the crust[J]. Acta Seismologica Sinica,2000,22(6):622–631.(in Chinese))
[36] 席道瑛. 花岗岩中矿物相变的物性特征[J]. 矿物学报,1994,14(3):223–227.(XI Daoying. Physical characteristics of mineral phase transition in the granite[J]. Acta Mineralogica Sinica,1994,14(3):223–227.(in Chinese))
[37] 孙 强,张志镇,薛 雷,等. 岩石高温相变与物理力学性质变化[J]. 岩石力学与工程学报,2013,32(5):935–942.(SUN Qiang,ZHANG Zhizhen,XUE Lei,et al. Physico-mechanical properties variation of rock with phase transformation under high temperature[J]. Chinese Journal of Rock Mechanics and Engineering,2013,32(5):935–942.(in Chinese))
[38] 赵忠魁,孙清州,张普庆,等. 高温焙烧对石英砂加热时的相变与膨胀性的影响[J]. 铸造,2006,55(9):961–964.(ZHAO Zhongkui,SUN Qingzhou,ZHANG Puqing,et al. Effect of calcinatin on phase transformation and expansibility of quartz sands during heating[J]. Foundry,2006,55(9):961–964.(in Chinese))
[39] 谢和平. 分形–岩石力学导论[M]. 北京:科学出版社,1996:95–97.(XIE Heping. Introduction for fractals-rock mechanics[M]. Beijing:Science Press,1996:95–97.(in Chinese))
[40] 张志镇,高 峰. 岩石变形破坏过程中的能量演化机制[M]. 徐州:中国矿业大学出版社,2014:110–117.(ZHANG Zhizhen,GAO Feng. Energy evolution mechanism during rock deformation and failure[M]. Xuzhou:China University of Mining and Technology Press,2014:110–117.(in Chinese))
[41] BAUD P,WONG T F,ZHU W. Effects of porosity and crack density on the compressive strength of rocks[J]. International Journal of Rock Mechanics and Mining Sciences,2014,67:202–211.
[42] FRIESEN W J,MIKULA R J. Fractal dimensions of coal particles[J]. Colloid Interface Science,1987,120:263–271.