川南地区志留系龙马溪组页岩力学性质及微观破裂机理

doi:10.11743/ogg20240517

Abstract

Abstract:

To reveal the mechanical properties and microfracturing mechanisms of shales， we investigate shales in the Silurian Longmaxi Formation in the southern Sichuan Basin using X-ray diffraction （XRD） analysis， together with triaxial compression， micro-computed tomography （micro-CT） and scanning electron microscopy （SEM） tests. The results indicate that the mechanical properties and reservoir physical properties of shale are significantly influenced by its mineral composition and confining pressure. Specifically， an increase in the brittle mineral content enhances its elastic modulus and peak stress， indicating positive correlations between these mechanical properties and the brittle mineral content. In contrast， higher clay mineral content increases the shale plasticity while reducing its rock strength. As confining pressure increases， fractures in the shale gradually close， and the pores deform and contract， leading to reduced porosity. A higher confining pressure results in greater compression. Two dominant types of fractures form during shale damage： boundary fractures occurring at interfaces between mineral grains and internal fractures occurring within grains. For shales with similar mechanical properties， increasing confining pressure shifts their dominant fracture type from boundary to internal fractures. Additionally， higher confining pressure causes the boundary and internal fractures to evolve into fracture zones， leading to an increased fracture density in the shale.

Key words: microfracturing mechanism, fracture, rock mechanics, shale, Longmaxi Formation, Silurian, southern Sichuan Basin

CLC Number:

TE122.2

Xun GONG, Zhijun JIN, Xinhua MA, Yuyang LIU, Guanfang LI, Huan MIU. Mechanical properties of the Silurian Longmaxi Formation shale， southern Sichuan Basin and its microfracturing mechanisms[J]. Oil & Gas Geology, 2024, 45(5): 1447-1455.

Figures/Tables 9

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References 39

1	邹才能，赵群，丛连铸，等. 中国页岩气开发进展、潜力及前景［J］. 天然气工业， 2021， 41（1）： 1-14.
	ZOU Caineng， ZHAO Qun， CONG Lianzhu， et al. Development progress， potential and prospect of shale gas in China［J］. Natural Gas Industry， 2021， 41（1）： 1-14.
2	马新华，张晓伟，熊伟，等. 中国页岩气发展前景及挑战［J］. 石油科学通报， 2023， 8（4）： 491-501.
	MA Xinhua， ZHANG Xiaowei， XIONG Wei， et al. Prospects and challenges of shale gas development in China［J］. Petroleum Science Bulletin， 2023， 8（4）： 491-501.
3	马新华. 四川盆地南部页岩气富集规律与规模有效开发探索［J］. 天然气工业， 2018， 38（10）： 1-10.
	MA Xinhua. Enrichment laws and scale effective development of shale gas in the southern Sichuan Basin［J］. Natural Gas Industry， 2018， 38（10）： 1-10.
4	金之钧，白振瑞，高波，等. 中国迎来页岩油气革命了吗？［J］. 石油与天然气地质， 2019， 40（3）： 451-458.
	JIN Zhijun， BAI Zhenrui， GAO Bo， et al. Has China ushered in the shale oil and gas revolution？［J］. Oil & Gas Geology， 2019， 40（3）： 451-458.
5	王红岩，周尚文，赵群，等. 川南地区深层页岩气富集特征、勘探开发进展及展望［J］. 石油与天然气地质， 2023， 44（6）： 1430-1441.
	WANG Hongyan， ZHOU Shangwen， ZHAO Qun， et al. Enrichment characteristics， exploration and exploitation progress， and prospects of deep shale gas in the southern Sichuan Basin， China［J］. Oil & Gas Geology， 2023， 44（6）： 1430-1441.
6	孙川翔，聂海宽，苏海琨，等. 温压耦合作用下四川盆地深层龙马溪组页岩孔渗和岩石力学特征［J］. 石油勘探与开发， 2023， 50（1）： 77-88.
	SUN Chuanxiang， NIE Haikuan， SU Haikun， et al. Porosity， permeability and rock mechanics of Lower Silurian Longmaxi Formation deep shale under temperature-pressure coupling in the Sichuan Basin， SW China［J］. Petroleum Exploration and Development， 2023， 50（1）： 77-88.
7	李庆辉，李少轩，刘伟洲. 深层页岩气储层岩石力学特性及对压裂改造的影响［J］. 特种油气藏， 2021， 28（3）： 130-138.
	LI Qinghui， LI Shaoxuan， LIU Weizhou. Rock mechanical properties of deep shale gas reservoirs and their influence on fracturing stimulation［J］. Special Oil & Gas Reservoirs， 2021， 28（3）： 130-138.
8	LIU Yang， CHEN Congrui， MA Tianshou， et al. Experimental investigation on the initiation of hydraulic fractures from a simulated wellbore in laminated shale［J］. Lithosphere， 2021， 2021（Special 4）： 4152918.
9	刘俊新，张可，刘伟，等. 不同围压及应变速率下页岩变形及破损特性试验研究［J］. 岩土力学， 2017， 38（）： 43-52.
	LIU Junxin， ZHANG Ke， LIU Wei， et al. Experimental study of mechanical behaviours of shale under different confining pressures and different strain rates［J］. Rock and Soil Mechanics， 2017， 38（S1）： 43-52.
10	LIU Jiantong， GE Hongkui， XUE Xianjie， et al. Study on fracture development in glutenite reservoir［C］//56th U.S. Rock Mechanics/Geomechanics Symposium， Santa Fe， 2022. Westminster， CO： American Rock Mechanics Association， 2022： ARMA-2022- 0009.
11	王春萍，王璐，刘建锋，等. 单轴压缩条件下单裂隙花岗岩力学特性及破坏特征［J］. 西南交通大学学报， 2024， 59（2）： 369-376， 446.
	WANG Chunping， WANG Lu， LIU Jianfeng， et al. Mechanical properties and failure characteristics of granite intersected with single fractures under uniaxial compression［J］. Journal of Southwest Jiaotong University， 2024， 59（2）： 369-376， 446.
12	ZHOU Tao， HAN Dongya， ZHU Jianbo. An experimental study of damage evolution in granite under compression and its influence on wave propagation［J］. Rock Mechanics and Rock Engineering， 2023， 56（5）： 3413-3427.
13	衡帅，刘晓，李贤忠，等. 张拉作用下页岩裂缝扩展演化机制研究［J］. 岩石力学与工程学报， 2019， 38（10）： 2031-2044.
	HENG Shuai， LIU Xiao， LI Xianzhong， et al. Study on the fracture propagation mechanisms of shale under tension［J］. Chinese Journal of Rock Mechanics and Engineering， 2019， 38（10）： 2031-2044.
14	韩兵，杨宏伟. 不同围压下页岩三轴压缩声发射能量分布特性研究［J］. 煤炭科学技术， 2019， 47（4）： 90-95.
	HAN Bing， YANG Hongwei. Study on distribution characteristics of shale triaxial compression acoustic emission energy under different confining pressures［J］. Coal Science and Technology， 2019， 47（4）： 90-95.
15	ZHAO Yu， ZHANG Yongfa， YANG Haiqing， et al. Experimental study on relationship between fracture propagation and pumping parameters under constant pressure injection conditions［J］. Fuel， 2022， 307： 121789.
16	DUAN Yongting， LI Xiao， ZHENG Bo， et al. Cracking evolution and failure characteristics of longmaxi shale under uniaxial compression using real-time computed tomography scanning［J］. Rock Mechanics and Rock Engineering， 2019， 52（9）： 3003-3015.
17	DUAN Yongting， LI Xiao， HE Jianming， et al. Quantitative analysis of meso-damage evolution for shale under in situ uniaxial compression conditions［J］. Environmental Earth Sciences， 2018， 77（4）： 154.
18	唐摩天，邬忠虎，王安礼，等. 不同围压下页岩微观破裂过程与量化研究［J］. 地下空间与工程学报， 2022， 18（2）： 438-445， 457.
	TANG Matian， WU Zhonghu， WANG Anli， et al. Microscopic fracture process and quantitative study of shale under different confining pressures［J］. Chinese Journal of Underground Space and Engineering， 2022， 18（2）： 438-445， 457.
19	柴金飞，吴顺川，高永涛，等. 基于矩张量P-T图的岩石单轴压缩破裂机理研究［J］. 中国矿业大学学报， 2016， 45（3）： 500-506.
	CHAI Jinfei， WU Shunchuan， GAO Yongtao， et al. Rock failure mechanism under uniaxial compression condition based on P-T diagram of moment tensors［J］. Journal of China University of Mining & Technology， 2016， 45（3）： 500-506.
20	LIU Xiuyang， XU Dingping， LI Shaojun， et al. An insight into the mechanical and fracture characterization of minerals and mineral interfaces in granite using nanoindentation and micro X-ray computed tomography［J］. Rock Mechanics and Rock Engineering， 2023， 56（5）： 3359-3375.
21	张晨晨，刘滋，董大忠，等. 深层海相页岩脆性特征分析与表征［J］. 新疆石油地质， 2019， 40（5）： 555-563.
	ZHANG Chenchen， LIU Zi， DONG Dazhong， et al. Brittleness analysis and characterization of deep marine shales［J］. Xinjiang Petroleum Geology， 2019， 40（5）： 555-563.
22	曹丹平，韩金鑫，肖竣夫，等. 弹性特征约束下的矿物成分页岩脆性评价方法研究［J］. 地球物理学报， 2023， 66（11）： 4781-4791.
	CAO Danping， HAN Jinxin， XIAO Junfu， et al. Method for evaluating the brittleness of shale minerals under the constraints of elastic characteristics［J］. Chinese Journal of Geophysics， 2023， 66（11）： 4781-4791.
23	崔春兰，董振国，吴德山. 湖南保靖区块龙马溪组岩石力学特征及可压性评价［J］. 天然气地球科学， 2019， 30（5）： 626-634.
	CUI Chunlan， DONG Zhenguo， WU Deshan. Rock mechanics study and fracability evaluation for Longmaxi Formation of Baojing block in Hunan Province［J］. Natural Gas Geoscience， 2019， 30（5）： 626-634.
24	赖富强，刘粤蛟，张海杰，等. 基于数字岩心模拟的深层页岩气储层可压性评价模型［J］. 中国石油大学学报（自然科学版）， 2022， 46（5）： 1-11.
	LAI Fuqiang， LIU Yuejiao， ZHANG Haijie， et al. Fracturing properties model of deep shale gas reservoir based on digital core simulation［J］. Journal of China University of Petroleum（Edition of Natural Science）， 2022， 46（5）： 1-11.
25	王磊，邹鹏，谢广祥，等. 深部原位应力煤岩卸荷力学特性试验研究［J］. 岩石力学与工程学报， 2023， 42（12）： 2876-2887.
	WANG Lei， ZOU Peng， XIE Guangxiang， et al. Experimental study on unloading mechanical properties of deep coal under in-situ stresses［J］. Chinese Journal of Rock Mechanics and Engineering， 2023， 42（12）： 2876-2887.
26	张旭龙，张盛，王龙飞，等. 基于砂岩三轴加载过程声发射与波速变化的峰前特征应力识别研究［J］. 岩石力学与工程学报， 2023， 42（11）： 2711-2726.
	ZHANG Xulong， ZHANG Sheng， WANG Longfei， et al. Identification of pre-peak characteristic stress of sandstone under triaxial loading based on acoustic emission and wave velocity variation［J］. Chinese Journal of Rock Mechanics and Engineering， 2023， 42（11）： 2711-2726.
27	郝宪杰，杨怀翔，张通，等. 深部煤系储层损伤扩容点的天然裂隙与围压效应及声发射识别［J］. 中国矿业大学学报， 2023， 52（4）： 648-659.
	HAO Xianjie， YANG Huaixiang， ZHANG Tong， et al. Effect of natural fracture and confining pressure on damage-dilatancy point of deep coal measures reservoir and acoustic emission identification［J］. Journal of China University of Mining & Technology， 2023， 52（4）： 648-659.
28	张培森，许大强，颜伟，等. 不同围压下峰后循环载荷对砂岩力学及渗流特性的影响研究［J］. 煤炭科学技术， 2023， 51（7）： 94-105.
	ZHANG Peisen， XU Daqiang， YAN Wei， et al. Effect of post-peak cyclic load on mechanics and seepage characteristics of sandstone under different confining pressures［J］. Coal Science and Technology， 2023， 51（7）： 94-105.
29	边瑞康，孙川翔，聂海宽，等. 四川盆地东南部五峰组-龙马溪组深层页岩气藏类型、特征及勘探方向［J］. 石油与天然气地质， 2023， 44（6）： 1515-1529.
	BIAN Ruikang， SUN Chuanxiang， NIE Haikuan， et al. Types， characteristics，and exploration targets of deep shale gas reservoirs in the Wufeng-Longmaxi formations， southeastern Sichuan Basin［J］. Oil & Gas Geology， 2023， 44（6）： 1515-1529.
30	葛勋，郭彤楼，马永生，等. 四川盆地东南缘林滩场地区上奥陶统五峰组-龙马溪组页岩气储层甜点预测［J］. 石油与天然气地质， 2022， 43（3）： 633-647.
	GE Xun， GUO Tonglou， MA Yongsheng， et al. Prediction of shale reservoir sweet spots of the Upper Ordovician Wufeng-Longmaxi formations in Lintanchang area， southeastern margin of Sichuan Basin［J］. Oil & Gas Geology， 2022， 43（3）： 633-647.
31	李恒，杨圣奇，孙博文，等. 双裂隙复合岩层单轴压缩力学性质及损伤机理离散元模拟［J］. 中南大学学报（自然科学版）， 2023， 54（10）： 4000-4014.
	LI Heng， YANG Shengqi， SUN Bowen， et al. Discrete element simulation of mechanical properties and damage mechanism of composite rock containing two fissures under uniaxial compression［J］. Journal of Central South University （Science and Technology）， 2023， 54（10）： 4000-4014.
32	胡训健，卞康，刘建，等. 离散裂隙网络对岩石力学性质和声发射特性影响的颗粒流分析［J］. 岩土力学， 2022， 43（）： 542-552.
	HU Xunjian， BIAN Kang， LIU Jian， et al. Particle flow code analysis of the effect of discrete fracture network on rock mechanical properties and acoustic emission characteristics［J］. Rock and Soil Mechanics， 2022， 43（S1）： 542-552.
33	李克升，刘传孝. 梯级等幅周期循环荷载作用下双裂隙黄砂岩力学特性试验研究［J］. 岩石力学与工程学报， 2023， 42（8）： 1945-1958.
	LI Kesheng， LIU Chuanxiao. Experimental investigation on mechanical properties of yellow sandstone samples containing two coplanar fissures under multistage constant-amplitude-cyclic loading［J］. Chinese Journal of Rock Mechanics and Engineering， 2023， 42（8）： 1945-1958.
34	李庆辉，陈勉，金衍，等. 含气页岩破坏模式及力学特性的试验研究［J］. 岩石力学与工程学报， 2012， 31（）： 3763-3771.
	LI Qinghui， CHEN Mian， JIN Yan， et al. Experimental research on failure modes and mechanical behaviors of gas-bearing shale［J］. Chinese Journal of Rock Mechanics and Engineering， 2012， 31（S2）： 3763-3771.
35	王濡岳，胡宗全，龙胜祥，等. 四川盆地上奥陶统五峰组-下志留统龙马溪组页岩储层特征与演化机制［J］. 石油与天然气地质， 2022， 43（2）： 353-364.
	WANG Ruyue， HU Zongquan， LONG Shengxiang， et al. Reservoir characteristics and evolution mechanisms of the Upper Ordovician Wufeng-Lower Silurian Longmaxi shale， Sichuan Basin［J］. Oil & Gas Geology， 2022， 43（2）： 353-364.
36	王鹏威，陈筱，刘忠宝，等. 海相富有机质页岩储层压力预测方法——以涪陵页岩气田上奥陶统五峰组-下志留统龙马溪组页岩为例［J］. 石油与天然气地质， 2022， 43（2）： 467-476.
	WANG Pengwei， CHEN Xiao， LIU Zhongbao， et al. Reservoir pressure prediction for marine organic-rich shale： A case study of the Upper Ordovician Wufeng-Lower Silurian Longmaxi shale in Fuling shale gas field， NE Sichuan Basin［J］. Oil & Gas Geology， 2022， 43（2）： 467-476.
37	张家伟，刘向君，熊健，等. 含裂缝页岩在围压下力学特性及破坏模式［J］. 科学技术与工程， 2023， 23（17）： 7300-7309.
	ZHANG Jiawei， LIU Xiangjun， XIONG Jian， et al. Mechanics and failure modes of fractured shale under different confining pressures［J］. Science Technology and Engineering， 2023， 23（17）： 7300-7309.
38	王飞，吴宝成，廖凯，等. 从闷井压力反演页岩油水平井压裂裂缝参数和地层压力［J］. 新疆石油地质， 2022， 43（5）： 624-629.
	WANG Fei， WU Baocheng， LIAO Kai， et al. Inversion of fracture parameters and formation pressure for fractured horizontal wells in shale oil reservoir based on soaking pressure［J］. Xinjiang Petroleum Geology， 2022， 43（5）： 624-629.
39	候梦如，梁冰，孙维吉，等. 矿物界面刚度对页岩水力压裂裂缝扩展规律的影响研究［J］. 油气藏评价与开发， 2023， 13（1）： 100-107.
	HOU Mengru， LIANG Bing， SUN Weiji， et al. Influence of mineral interface stiffness on fracture propagation law of shale hydraulic fracturing［J］. Petroleum Reservoir Evaluation and Development， 2023， 13（1）： 100-107.

样品编号	实验条件	实验结果
样品编号	围压/MPa	峰值应力/MPa	峰值应变/ %	弹性模量/GPa	泊松比
1-1	15	145.25	1.19	14.36	0.27
1-2	15	153.60	1.36	14.43	0.25
1-3	15	96.82	0.96	14.32	0.20
1-4	20	161.35	1.31	16.47	0.21
1-5	25	193.68	1.64	16.64	0.18

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Mechanical properties of the Silurian Longmaxi Formation shale， southern Sichuan Basin and its microfracturing mechanisms

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