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| Research on the evolution law of mechanics and fracture characteristics of oil shale under real-time high temperature conditions |
| YANG Shaoqiang1，2，ZHANG Qinglun1，YANG Dong3，WANG Lei3 |
(1. College of Engineering for Safety and Emergency Management，Taiyuan University of Science and Technology，Taiyuan，Shanxi 030024，China；2. Intelligent Monitoring and Control of Coal Mine Dust Key Laboratory of Shanxi Province，Taiyuan University of Science and Technology，Taiyuan，Shanxi 030024，China；3. Key Laboratory of In-Situ Property-Improving
Mining of Ministry of Education，Taiyuan University of Technology，Taiyuan，Shanxi 030024，China) |
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Abstract In order to obtain the effects of temperature and bedding plane on the microstructure，macroscopic mechanical parameters and fracture characteristics during the in-situ pyrolysis of oil shale，the self-developed real-time high-temperature thermo-mechanical coupling CT scanning device and high-temperature rock mechanics test system were used to carry out thermo-mechanical coupling CT scanning and uniaxial compression tests on oil shale in two directions of perpendicular to bedding and parallel to bedding from 20 ℃ to 600 ℃. The results reveal that：(1) Up to 400 ℃，the stress state of oil shale is the key factor to determine the law of pore fracture propagation. Under perpendicular loading to the bedding，the pore diameter and fracture aperture initially decreasing and then increasing with temperature increasing. Under parallel loading to the bedding，primary fractures propagate along the bedding planes，accompanied by the emergence of new fractures. (2) When loading in both perpendicular to and parallel bedding directions，the compressive strength，elastic modulus，and Poisson's ratio of oil shale initially decreasing and then increasing. Specifically，the compressive strength and elastic modulus reach their minimum values at 400 ℃，whereas the Poisson?s ratio attains its minimum at 500 ℃ and 200 ℃ when loading perpendicular to bedding and parallel to bedding，respectively. (3) Except for the the fracture damage stress during perpendicular bedding loading initially increases，then decreases，and subsequently increases with temperature，the initial stress during perpendicular bedding loading ，parallel bedding loading ，and damage stress decrease initially and then increase，reaching their minimum values at 400 ℃. These research findings provide essential data for reservoir reconstruction and cementing technology in the in-situ mining process of oil shale.
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[1] KANG Z，ZHAO Y，YANG D. Review of oil shale in-situ conversion technology[J]. Applied Energy，2020，269：115–121.
[2] Tiwari，P. Oil shale pyrolysis：Benchscale experimental studies and modeling[Ph. D. Thesis][D]. Salt•Lake City，UT：University of Utah，2012.
[3] ZHU Y，LIU K，ZHONG X，et al. Experimental investigation on the anisotropic behaviors induced by bedding planes in mechanical properties of ma?quan oil shale[J]. Arabian Journal for Science and Engineering，2021，47：11 385–11 403.
[4] 赵阳升，冯增朝，杨 栋，等. 对流加热油页岩开采油气的方法[P]. 中国：CN200510012473.4，2005–10–05.(ZHAO Yangsheng，FENG Zengchao，YANG Dong，et al. The method for mining oil and gas from oil shale by convection heating. china patent[P]. China：CN200510012473.4，2005–10–05.(in Chinese))
[5] 王 磊，杨 栋，康志勤. 高温水蒸汽作用后油页岩渗透特性及各向异性演化的试验研究[J]. 岩石力学与工程学报，2021，40(11)： 2 286–2 295.(WANG Lei，YANG Dong，KANG Zhiqin. Experimental study on permeability characteristics and anisotropy evolution of oil shale after high-temperature water vapor treatment[J]. Chinese Journal of Rock Mechanics and Engineering，2021，40(11)：2 286–2 295.(in Chinese))
[6] KIM H，CHO J W，SONG I，et al. Anisotropy of elastic moduli，P-wave velocities，and thermal conductivities of Asan Gneiss，Boryeong Shale，and Yeoncheon Schist in Korea[J]. Engineering Geology，2012，147–148：68–77.
[7] ISLAM M A，SKALLE P. An experimental investigation of shale mechanical properties through drained and undrained test mechanisms[J]. Rock Mechanics and Rock Engineering，2013，46(6)：1 391–1 413.
[8] CHO J W，KIM H，JEON S，et al. Deformation and strength anisotropy of Asan gneiss，Boryeong shale，and Yeoncheon schist[J]. International Journal of Rock Mechanics and Mining Sciences，2012，50：158–169.
[9] ROY D G，SINGH T N，KODIKARA J. Influence of joint anisotropy on the fracturing behavior of a sedimentary rock[J]. Engineering Geology，2017，228：224–237.
[10] JIN Z，LI W，JIN C，et al. Anisotropic elastic，strength，and fracture properties of Marcellus shale[J]. International Journal of Rock Mechanics and Mining Sciences，2018，109：124–137.
[11] 李存宝，谢和平，谢凌志. 页岩起裂应力和裂纹损伤应力的试验及理论[J]. 煤炭学报，2017，42：969–976.(LI Cunbao，XIE Heping，XIE Lingzhi. Anisotropic characteristics of crack initiation and crack damage thresholds for shale[J]. Journal of China Coal Society，2017，40(4)：969–976.(in Chinese))
[12] 陈立超，张典坤，吕帅锋. 层理方位对页岩断裂性能与裂缝延展模式的影响[J]. 地下空间与工程学报，2023，19(6)：1 878–1 886. (CHEN Lichao，ZHANG Diankun，LV Shuaifeng. Effect of bedding orientation on fracture properties and fracture propagation mode of shale[J]. Chinese Journal of Underground Space and Engineering，2013，19(6)：1 878–1 886.(in Chinese))
[13] WANG P，REN F，MIAO S，et al. Evaluation of the anisotropy and directionality of a jointed rock mass under numerical direct shear tests[J]. Engineering Geology，2017，225：29–41.
[14] LI K，YIN Z Y，HAN D，et al. Size Effect and Anisotropy in a Transversely Isotropic Rock Under Compressive Conditions[J]. Rock Mechanics and Rock Engineering，2021，54(9)：4 639–4 662.
[15] NEJATI M，AMINZADEH A，AMANN F，et al. Mode I fracture growth in anisotropic rocks：Theory and experiment[J]. International Journal of Solids and Structures，2020，195(15)：74–90.
[16] WU S，YU Z，KANG J，et al. Research on the anisotropy of thermal conductivity of rocks in Songliao basin，China[J]. Renewable Energy，2021，179：593–603.
[17] 丁 恒，刘 兵. 层状灰岩各向异性力学特征及声发射演化试验分析[J]. 科技和产业，2021，21：339–344.(DING Heng，LIU Bing. Experimental analysis of anisotropic mechanical characteristics and acoustic emission evolution of layered limestone[J]. Science Technology and Industry，2021，21：339–344.(in Chinese))
[18] GAO Q，TAO J，HU J，et al. Laboratory study on the mechanical behaviors of an anisotropic shale rock [J]. Journal of Rock Mechanics and Geotechnical Engineering，2015，(7)：213–219.
[19] YANG G，LIU J，LI X，et al. Effect of temperature on shale strength under dynamic impact loading[J]// Arabian Journal of Geosciences，2020，13(12)：432–441.
[20] VISHAL V，RIZWAN M，MAHANTA B，et al. Temperature effect on the mechanical behavior of shale：Implication for shale gas production[J]. Geosystems and Geoenvironment，2022，1(4)：100078.
[21] GUO Y，LI X，HUANG L. Changes in thermophysical and thermo-mechanical properties of thermally treated anisotropic shale after water cooling[J]. Fuel，2022，327：125241.
[22] CLOSMANN P J，BRADLEY W B. Effect of temperature on the tensile and compressive strength and Young?s modulus of oil shale[J]. Society of Petroleum Engineers Journal，1979，9(5)：301–312.
[23] GUO W，GUO Y，CAI Z，et al. Mechanical behavior and constitutive model of shale under real-time high temperature and high stress conditions[J]. Journal of Petroleum Exploration and Production Technology，2023，13(3)：827–841.
[24] GORSHKOV A M，KHOMYAKOV I S. Thermal treatment of reservoir as one of the powerful method of shale formation development in russia[C]// IOP Conference Series：Earth and Environmental Science.[S. l.]：[s. n.]，2019，272(3)：032004.
[25] AYLMORE M，LINCOLN F. Mechanochemical milling-induced reactions between gases and sulfide minerals：I. Reactions of SO2 with arsenopyrite，pyrrhotite and pyrite[J]. Journal of Alloys and Compounds，2000，309：61–74.
[26] LIU J D，XUE Y，QI Z，et al. Micro-cracking behavior of shale matrix during thermal recovery：Insights from phase-field modeling[J]. Engineering Fracture Mechanics，2020，239：107301.
[27] HEUZE F E. High-temperature mechanical，physical and thermal properties of granitic rocks—A review[J]. International Journal of Rock Mechanics and Mining Sciences and，1983，20(1)：3–10.
[28] KANG Z，ZHAO J，YANG D，et al. Study of the evolution of micron-scale pore structure in oil shale at different temperatures[J]. Oil Shale，2017，34(1)：42–54.
[29] BAI F，SUN Y，LIU Y，et al. Evaluation of the porous structure of Huadian oil shale during pyrolysis using multiple approaches[J]. Fuel，2017，187：1–8.
[30] YANG L，YANG D，ZHAO J，et al. Changes of oil shale pore structure and permeability at different temperatures[J]. Oil Shale，2016，33：101.
[31] GENG Y，LIANG W，LIU J，et al. Evolution of pore and fracture structure of oil shale under high temperature and high pressure[J]. Energy and Fuels，2017，31(10)：10 404–10 413.
[32] YILMAZ G. The effects of temperature on the characteristics of kaolinite and bentonite[J]. Scientific Research and Essays，2011，6(9)：1 928–1 939.
[33] ZHAO X，ZHANG X，LIU Z，et al. Organic matter in yilan oil shale：characterization and pyrolysis with or without inorganic minerals[J]. Energy and Fuels，2017，31(4)：3 784–3 792.
[34] EYMERY J P，YLLI F. Study of a mechanochemical transformation in iron pyrite[J]. Journal of Alloys and Compounds，2000，298(1/2)：306–309.
[35] WANG Y，ZHAI C，YU X，et al. Dynamic characteristics and damage evolution law of Wufeng formation-Longmaxi formation shale under high temperature effects[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(5)：1 110–1 123.
[36] ZHANG W，SUN Q，HAO S，et al. Experimental study on the variation of physical and mechanical properties of rock after high temperature treatment[J]. Applied Thermal Engineering，2016，98： 1 297–1 304.
[37] 张玉良，孙 强，李进学，等. 高温焙烧后黏土孔隙与力学特征研究[J]. 岩石力学与工程学报，2015，34(7)：1 480–1 488.(ZHANG Yuliang，SUN Qiang，LI Jinxue，et al. Pore and mechanical properties of clay after high temperature roasting[J]. Journal of Rock Mechanics and Engineering，2015，34(7)：1 480–1 488.(in Chinese))
[38] 王 宇，翟 成，余 旭，等. 高温作用下五峰组–龙马溪组页岩动力学特征及损伤演化规律研究[J]. 岩石力学与工程学报，2023，42(5)：1 110–1 123.(WANG Yu，ZHAI Cheng，YU Xu，et al. Dynamic characteristics and damage evolution law of Wufeng formation Longmaxi formation shale under high temperature effects[J]. Chinese Journal of Rock Mechanics and Engineering，2023，42(5)：1 110– 1 123.(in Chinese))
[39] YANG G，LIU J，LI X，et al. Effect of temperature on shale strength under dynamic impact loading[J]. Arabian Journal of Geosciences，2020，13(12)：432.
[40] 马文良. 升温过程中油页岩结构和力学演化规律及数值模拟应用研究[博士学位论文][D]. 长春：吉林大学，2022.(MA Wenliang. Study on the evolution laws of structural and mechanical characteristics of oil shale during temperature rise and the application of numerical simulation[Ph. D. Thesis][D]. Changchun：Jilin University，2022.(in Chinese))
[41] YANG S，YANG D，KANG Z. Experimental investigation of the anisotropic evolution of tensile strength of oil shale under real-time high-temperature conditions[J]. Natural Resources Research，2021，30(3)：2 513–2 528.
[42] 赵 静. 高温及三维应力下油页岩细观特征及力学特性试验研究[博士学位论文][D]. 太原：太原理工大学，2014.(ZHAO Jing. Experimental study on the microscopic characteristics and mechanical property of oil shale under high temperature and three-dimensional stress[Ph. D. Thesis][D]. Taiyuan：Taiyuan University of Technology，2014.(in Chinese))
[43] 王 擎，孙 斌，刘洪鹏，等. 油页岩热解过程矿物质行为分析[J]. 燃料化学学报，2013，41(2)：163–168.(WANG Qing，SUN Bin，LIU Hongpeng，et al. Analysis of mineral behavior during pyrolysis of oil shale[J]. Journal of Fuel Chemistry and Technology，2013，41(2)：163–168.(in Chinese))
[44] GUO W，GUO Y，CAI Z，et al. Mechanical behavior and constitutive model of shale under real-time high temperature and high stress conditions[J]. Journal of Petroleum Exploration and Production Technology，2023，13(3)：827–841.
[45] ZHAO G，FAN Y，TANG C，et al. Preparation and compressive properties of cementitious composites reinforced by 3D printed cellular structures with a negative Poisson?s ratio[J]. Developments in the Built Environment，2024，17：100362.
[46] WANG X，XIE H，ZHANG R，et al. Progressive failure characterization of sandstone from Yingjinshan area in Qinghai—Tibet plateau[J]. Rock Mechanics and Rock Engineering，2022，55(11).：6 723–6 740.
[47] BRACE W F，PAULDING B W，SCHOLZ C. Dilatancy in the fracture of crystalline rocks[J]. Journal of Geophysical Research，1966，71(16)：3 939–3 953.
[48] CHEN G，WANG J，LI J，et al. Influence of temperature on crack initiation and propagation in granite[J]. International Journal of Geomechanics，2018，18(8)：4018094. |
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2024, Vol. 43 
