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| Study on softening constitutive model of deep shale under hydration |
| ZHAO Zhihong1，JIN Haozeng1，GUO Jianchun1，CHEN Mengting2，LU Cong1 |
| (1. State Key Laboratory of Oil and Gas Reservoir Geology and Development Engineering，Southwest Petroleum University，Chengdu，Sichuan 610500，China；2. Petroleum Engineering Institute of Sinopec Shanghai Offshore Oil and
Gas Company，Shanghai 200120，China) |
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Abstract Given the lack of the understanding for the hydration leads to softening mechanism of deep shale and the corresponding constitutive model，based on the laboratory experiment and theoretical model research on the deep shale of longmaxi formation in Sichuan Basin，establishing the softening constitutive model of hydration. Firstly，carrying out the experiment of free immersion in clean water. Then CT scanning is performed on rock samples with different soaking time，and CT gray histogram is drawn to analyze the meso-damage mechanism of hydration，and carrying out the triaxial compression test on soaking samples. Finally，establishing the softening constitutive model of shale under high closure pressure by using continuous damage mechanics and Weibull statistical theory. It is found that the main cause of shale hydration damage is the initiation and expansion of internal microcracks，the mechanical parameters，cohesion，peak strength and elastic modulus，decrease with the increase of hydration time，Poisson?s ratio increase with the increase of hydration time. In the stress-strain curve，the compaction stage and yield failure stage are obviously prolonged，and the model parameters m and decrease with the increase of hydration time，which macroscopically explains the softening of shale mechanical properties caused by hydration.
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| [1] 马新华，谢 军. 川南地区页岩气勘探开发进展及发展前景[J]. 石油勘探与开发，2018，45(1)：161–169.(MA Xinhua，XIE Jun. The progress and prospects of shale gas exploration and exploitation in southern Sichuan Basin，NW China[J]. Petroleum Exploration and Development，2018，45(1)：161–169.(in Chinese))
[2] 范 宇，周小金，曾 波，等. 密切割分段压裂工艺在深层页岩气Zi–2井的应用[J]. 新疆石油地质，2019，40(2)：223–227.(FAN Yu，ZHOU Xiaojin，ZENG Bo，et al. Application of intensive staged fracturing technology in deep shale gas well Zi–2[J]. Xinjiang Petroleum Geology，2019，40(2)：223–227.(in Chinese))
[3] 陈 作，李双明，陈 赞，等. 深层页岩气水力裂缝起裂与扩展试验及压裂优化设计[J]. 石油钻探技术，2020，48(3)：70–76.(CHEN Zuo，LI Shuangming，CHEN Zan，et al. Hydraulic fracture initiation and extending tests in deep shale gas formations and fracturing design optimization[J]. Petroleum Drilling Techniques，2020，48(3)：70–76.(in Chinese))
[4] 李庆辉，陈 勉，WANG F，等. 工程因素对页岩气产量的影响—以北美Haynesville页岩气藏为例[J]. 天然气工业，2012，32(4)：54–59.(LI Qinghui，CHEN Mian，WANG F，et al. Influence of engineering factors on shale gas production—Taking Haynesville shale gas reservoir in North America as an example[J]. Natural Gas Industry，2012，32(4)：54–59.(in Chinese))
[5] SPEIGHT J G. Deep shale oil and gas[M]. [S. l.]：Gulf Professional Publishing，2016：1–60.
[6] SINGH，HARPREET. A critical review of water uptake by shales[J]. Journal of Natural Gas Science and Engineering，2016，34：751–766.
[7] 钱 斌，朱炬辉，杨 海，等. 页岩储集层岩心水化作用试验[J]. 石油勘探与开发，2017，44(4)：615–621.(QIAN Bin，ZHU Juhui，YANG Hai，et al. Hydration test of shale reservoir core[J]. Petroleum exploration and development，2017，44(4)：615–621.(in Chinese))
[8] LIANG L，XIONG J，LIU X. Experimental study on crack propagation in shale formations considering hydration and wettability[J]. Journal of Natural Gas Science and Engineering，2015，23：492–499.
[9] ZHOU Z，ABASS H，LI X，et al. Experimental investigation of the effect of imbibition on shale permeability during hydraulic fracturing[J]. Journal of Natural Gas Science and Engineering，2016，29：413–430.
[10] PRICE N J. The compressive strength of coal measure rocks[J]. 1960.
[11] VUTUKURI V S. The effect of liquids on the tensile strength of limestone [J]. International Journal of Rock Mechanics and Mining Sciences and Geomechanics Abstracts，1974，11(1)：27–29.
[12] FEDA J. The influence of water content on the behaviour of subsoil formed by highly weathered rock[C]//Proceedings of the 1st ISRM Congress. [S.l.]：[s. n.]，1966：49.
[13] BURSHTEIN L S. Effect of moisture on the strength and deformability of sandstone[J]. Soviet Mining，1969，5(5)：573–576.
[14] RUIZ M. Some technological of twenty-six characteristics brazilian rock types[C]//Proceedings of the 1st ISRM Congress. [S.l.]：[s. n.]，1966：23.
[15] 姜永东，鲜学福，许 江，等. 砂岩单轴三轴压缩试验研究[J]. 中国矿业，2004，13(4)：66–69.(JIANG Yongdong，XIAN Xuefu，XU Jiang. Experimental study on uniaxial triaxial compression of sandstone[J]. China Mining Industry，2004，13(4)：66–69.(in Chinese))
[16] 乔丽苹. 砂岩弹塑性及蠕变特性的水物理化学作用效应试验与本构研究[博士学位论文][D]. 北京：中国科学院研究生院，2008. (QIAO Liping. Experimental-theoretical-numerical studies of elasto-plastic and creep property of sandstone with hydro-physico-chemical influencing effects[Ph. D. Thesis][D]. Beijing：Graduate School of Chinese Academy of Sciences，2008.(in Chinese))
[17] 乔丽苹，刘 建，冯夏庭. 砂岩水物理化学损伤机制研究[J]. 岩石力学与工程学报，2007，26(10)：2 117–2 124.(QIAO Liping，LIU Jian，FENG Xiating. Study on the mechanism of sandstone hydro physical and chemical damage[J]. Chinese Journal of Rock Mechanics and Engineering，2007，26(10)：2 117–2 124.(in Chinese))
[18] OJO O，BROOK N. The effect of moisture on some mechanical properties of rock[J]. Mining Science and Technology，1990，10(2)：145–156.
[19] ASCH T，HENDRIKS M R，HESSEL R，et al. Hydrological triggering conditions of landslides in varved clays in the French Alps[J]. Engineering Geology，1996，42(4)：239–251.
[20] 康毅力，杨 斌，李相臣，等. 页岩水化微观作用力定量表征及工程应用[J]. 石油勘探与开发，2017，44(2)：301–308.(KANG Yili，YANG Bin，LI Xiangchen，et al. Quantitative characterization of micro forces in shale hydration and field applications[J]. Petroleum Exploration and Development，2017，42(2)：301–308.(in Chinese))
[21] ZHOU T，ZHANG S，YANG L，et al. Experimental investigation on fracture surface strength softening induced by fracturing fluid imbibition and its impacts on flow conductivity in shale reservoirs[J]. Journal of Natural Gas Science and Engineering，2016，S1875510016 307727.
[22] 游 强，游 猛. 岩石统计损伤本构模型及对比分析[J]. 兰州理工大学学报，2011，37(3)：119–123.(YOU Qiang，YOU Meng. Statistical damage constitutive models of rock and their comparative analysis[J]. Journal of Lanzhou University of Technology，2011，37(3)：119–123.(in Chinese))
[23] 杨友卿. 岩石强度的损伤力学分析[J]. 岩石力学与工程学报，1999，18(1)：24–28.(YANG Youqing. Continuum damage mechanics analysis on strength of rock[J]. Chinese Journal of Rock Mechanics and Engineering，1999，18(1)：24–28.(in Chinese))
[24] CHRISTENSEN N I. Poisson?s ratio and crustal seismology[J]. Journal of Geophysical Research：Solid Earth，1996，101(B2)：3 139–56.
[25] 杨更社，刘 慧. 基于CT图像处理技术的岩石损伤特性研究[J]. 煤炭学报，2007，32(5)：463–468.(YANG Gengshe，LIU Hui. Study on the rock damage characteristics based on the technique of CT image processing[J]. Journal of China Coal Society，2007，32(5)：463–468.(in Chinese))
[26] 吴 政，张承娟. 单向荷载作用下岩石损伤模型及其力学特性研究[J]. 岩石力学与工程学报，1996，15(1)：55–61.(WU Zheng，ZHAGN Chengjuan. Investigation of rock damage model，and its mechanical behaviour[J]. Chinese Journal of Rock Mechanics and Engineering，1996，15(1)：55–61.(in Chinese))
[27] ZOU C，DONG D，WANG Y，et al. Shale gas in China：Characteristics，challenges and prospects(II)[J]. Petroleum Exploration and Development，2015，43(6)：182–196.
[28] 徐卫亚，韦立德. 岩石损伤统计本构模型的研究[J]. 岩石力学与工程学报，2002，21(6)：787–791.(XU Weiya，WEI Lide. Study on statistical constitutive model of rock damage[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(6)：787–791.(in Chinese))
[29] 曹文贵，赵明华，唐学军. 岩石破裂过程的统计损伤模拟研究[J]. 岩土工程学报，2003，25(2)：184–187.(CAO Wengui，ZHAO Minghuha，TANG Xuejun. Statistical damage simulation of rock fracture process[J]. Chinese Journal of Rock Mechanics and Engineering，2003，25(2)：184–187.(in Chinese))
[30] 李 博，吴润江，高为超.岩石损伤软化的修正本构模型[J]. 地震学报，2016，38(5)：783–786.(LI Bo，WU Runjiang，GAO Weichao. A modified damage softening constitutive model for rock[J]. China Earthquake Engineering Journal，2016，38(5)：783–786.(in Chinese)) |
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2022, Vol. 41 
