Although spectacular advances in shale gas reservoir stimulation,
i.e., hydraulic fracturing, the deformation behavior and failure mechanism
of shale are not understood well enough. The basic reason is that
shale contains stratified structure named bedding plane and its complicated
petrophysical properties. The mechanical behavior of shale as the
loading direction is parallel to the bedding plane is significantly
different from that as the loading direction is perpendicular to the
bedding plane. This work is devoted to characterization of the Longmaxi
shale deformation and failure mechanism through experiments, from
which 4 different deformation stages are obtained and volumetric strain
deformation behavior is analyzed systematically. Then the effects
of confinement as well as bedding layer orientation, which is defined
as the angle between the loading direction and normal direction of
bedding plane, on the elastic modulus, peak strength, and cohesion
of shale are investigated. The analytical results illustrate that
the volumetric strain dilatation is a constant, which is independent
on the confining pressure and bedding layer orientation; its brittleness
is high (0.55?0.85,
四川省科技计划项目-应用基础计划(2015JY0280)
四川省科技支撑计划(2012FZ0124)
[1] Zhang H X. Shale gas: New bright point of the exploitation of the global oil-gas resources––the present status and key problems of the exploitation of shale gas (in Chinese). Bull Chin Acad Sci, 2010, 25: 406–410 [张鸿翔. 页岩气: 全球油气资源开发的新亮点――我国页岩气开发的现状与关键问题. 中国科学院院刊, 2010, 25: 406–410]. Google Scholar
[2] Gensterblum Y, Ghanizadeh A, Cuss R J, et al. Gas transport and storage capacity in shale gas reservoirs—A review. Part A: Transport processes. J Unconventional Oil Gas Resources, 2015, 12: 87-122 CrossRef Google Scholar
[3] Yao J, Sun H, Huang Z Q, et al. Key mechanical problems in the developmentof shale gas reservoirs (in Chinese). Sci Sin-Phys Mech Astron, 2013, 43: 1527-1547 CrossRef Google Scholar
[4] Warlick D. Gas shale and CBM development in North America. Oil Gas Financial J, 2006, 3: 1–5. Google Scholar
[5] Wang J, Xie L, Xie H, et al. Effect of layer orientation on acoustic emission characteristics of anisotropic shale in Brazilian tests. J Nat Gas Sci Eng, 2016, 36: 1120-1129 CrossRef Google Scholar
[6] Gao Q, Hu J, Tao J, et al. Experimental characterization of the anisotropic behaviors of shale rock. In: Proceedings of Geo-Congress 2014 Technical Papers: Geo-characterization and modeling for sustainability. Reston: American Society of Civil Engineers, 2014. 563–571. Google Scholar
[7] Matzar L A, Gamwell C G. Understanding shale failure from laboratory analysis to field operations. In: Proceedings of 47th US rock mechanics/geomechanics symposium. Houston: American Rock Mechanics Association, 2013. Google Scholar
[8] Sone H, Zoback M D. Mechanical properties of shale-gas reservoir rocks—Part 1: Static and dynamic elastic properties and anisotropy. Geophysics, 2013, 78: D381-D392 CrossRef ADS Google Scholar
[9] Masri M, Sibai M, Shao J F, et al. Experimental investigation of the effect of temperature on the mechanical behavior of Tournemire shale. Int J Rock Mech Mining Sci, 2014, 70: 185-191 CrossRef Google Scholar
[10] Mohamadi M, Wan R G. Strength and post-peak response of Colorado shale at high pressure and temperature. Int J Rock Mech Mining Sci, 2016, 84: 34-46 CrossRef Google Scholar
[11] Josh M, Esteban L, Delle Piane C, et al. Laboratory characterisation of shale properties. J Pet Sci Eng, 2012, 88-89: 107-124 CrossRef Google Scholar
[12] Dewhurst D N, Bunger A, Josh M, et al. Mechanics, physics, chemistry and shale rock properties. In: Proceedings of 47th US Rock Mechanics/Geomechanics Symposium. Houston: American Rock Mechanics Association, 2013. Google Scholar
[13] Horsrud P, S?nsteb? E F, B?e R. Mechanical and petrophysical properties of North Sea shales. Int J Rock Mech Mining Sci, 1998, 35: 1009-1020 CrossRef Google Scholar
[14] Rybacki E, Reinicke A, Meier T, et al. What controls the mechanical properties of shale rocks?—Part I: Strength and Young’s modulus. J Pet Sci Eng, 2015, 135: 702-722 CrossRef Google Scholar
[15]
Sone H. Mechanical Properties of Shale Gas Reservoir Rocks, and Its Relation to the
[16] Yang Z P, He B, Xie L Z, et al. Strength and failure modes of shale based on Brazilian test (in Chinese). Rock Soil Mech, 2015, 36: 3447–3455 [杨志鹏, 何柏, 谢凌志, 等. 基于巴西劈裂试验的页岩强度与破坏模式研究. 岩土力学, 2015, 36: 3447–3455]. Google Scholar
[17] Sierra R, Tran M H, Abousleiman Y N, et al. Woodford Shale mechanical properties and the impacts of lithofacies. In: Proceedings of 44th US Rock Mechanics Symposium and 5th US-Canada Rock Mechanics Symposium. Houston: American Rock Mechanics Association, 2010. Google Scholar
[18] Jia C G, Chen J H, Guo Y T, et al. Research on mechanical behaviors and failure modes of layer shale (in Chinese). Rock Soil Mech, 2013, 34: 57–61 [贾长贵, 陈军海, 郭印同, 等. 层状页岩力学特性及其破坏模式研究. 岩土力学, 2013, 34: 57–61]. Google Scholar
[19] Lyu Q, Pg R, Long X, et al. Effects of coring directions on the mechanical properties of Chinese shale. Arab J Geosci, 2015, 8: 10289-10299 CrossRef Google Scholar
[20] Fj?r E, Nes O M. Strength anisotropy of Mancos shale. In: Proceedings of 47th US Rock Mechanics/Geomechanics Symposium. Houston: American Rock Mechanics Association, 2013. Google Scholar
[21] Niandou H, Shao J F, Henry J P, et al. Laboratory investigation of the mechanical behaviour of Tournemire shale. Int J Rock Mech Mining Sci, 1997, 34: 3-16 CrossRef Google Scholar
[22] Ba?ant Z P, Salviato M, Chau V T, et al. Why fracking works. J Appl Mech, 2014, 81: 101010 CrossRef ADS Google Scholar
[23] Liu J T, Liu S L, Li Y J, et al. Geochemistry characteristics and its geological significance of shale in the Ordovician Wufeng Formation and Silurian Longmaxi Formation, Jiaoshiba area (in Chinese). Pet Geol Recovery Efficiency, 2016, 23: 53–57 [刘江涛, 刘双莲, 李永杰, 等. 焦石坝地区奥陶系五峰组—志留系龙马溪组页岩地球化学特征及地质意义. 油气地质与采收率, 2016, 23: 53–57]. Google Scholar
[24] Xie L Z. Research on Salt Caverns for CO2 Sequestration Geotechnical Engineering (in Chinese). Dissertation for Dcotoral Degree. Chengdu: Sichuan University, 2012 [谢凌志. 盐穴CO2封存库的基础研究. 博士学位论文. 成都: 四川大学, 2012]. Google Scholar
[25] Holt R M, Fj?r E, Stenebr?ten J F, et al. Brittleness of shales: Relevance to borehole collapse and hydraulic fracturing. J Pet Sci Eng, 2015, 131: 200-209 CrossRef Google Scholar
[26] Rickman R, Mullen M J, Petre J E, et al. A practical use of shale petrophysics for stimulation design optimization: All shale plays are not clones of the Barnett Shale. In: Proceedings of SPE Annual Technical Conference and Exhibition. Denver: Society of Petroleum Engineers, 2008. Google Scholar
[27] Ismael M A, Imam H F, El-Shayeb Y. A simplified approach to directly consider intact rock anisotropy in Hoek-Brown failure criterion. J Rock Mech Geotech Eng, 2014, 6: 486-492 CrossRef Google Scholar
[28] McLamore R, Gray K E. The mechanical behavior of anisotropic sedimentary rocks. J Eng Indus, 1967, 89: 62-73 CrossRef Google Scholar
[29] Abousleiman Y N, Tran M H, Hoang S, et al. Geomechanics field and laboratory characterization of the Woodford Shale: The next gas play. In: Proceedings of SPE Annual Technical Conference and Exhibition. Richardson: Society of Petroleum Engineers, 2007. Google Scholar
[30] Li Q H, Chen M, Jin Y, et al. Experimental research on failure modes and mechanical behaviors of gas-bearing shale (in Chinese). Chin J Rock Mech Eng, 2012, 31: 3763–3771 [李庆辉, 陈勉, 金衍. 含气页岩破坏模式及力学特性的试验研究. 岩石力学与工程学报, 2012, 31: 3763–3771]. Google Scholar
[31] Kumar V, Sondergeld C H, Rai C S. Nano to macro mechanical characterization of shale. In: Proceedings of SPE Annual Technical Conference and Exhibition. Richardson: Society of Petroleum Engineers, 2012. Google Scholar
[32] Chong K P, Uenishi K, Smith J W, et al. Non-linear three dimensional mechanical characterization of Colorado oil shale. Int J Rock Mech Mining Sci Geomech Abstr, 1980, 17: 339–347. Google Scholar
[33] Gautam R, Wong R C. Transversely isotropic stiffness parameters and their measurement in Colorado shale. Can Geotech J, 2006, 43: 1290-1305 CrossRef Google Scholar
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