Investigation of shale fracture behavior with different bedding properties based on discrete element methodOA
The interaction between cemented laminae and induced fractures plays a critical role in hydraulic fracture propagation within laminated shale reservoirs.By combining mode-Ⅰfracture mechanics experiment conducted on semi-circular bend(SCB)specimens of black carbonaceous shale from the marine Longmaxi Formation with numerical simulations,this study systematically investigates the effects of three key geological parameters:(1)bond strength,(2)vein stiffness,and(3)approach angle on fracture propagation characteristics.The key findings are summarized as follows:(1)Increasing the parallel bond strength promotes fracture crossing behavior.When the vein fracture toughness was reduced to 0.3,0.2,and 0.1 times that of the shale matrix,fractures exhibited increased deflection tendency along the vein,creating longer stepped propagation paths.(2)For stiffer veins,induced fracture divert into the vein and propagate over longer distances;Additionally,more micro-cracks form within the vein before fracture-vein interaction occurs.(3)Fracture-vein interaction exhibits significant angular dependence:At approach angles between 60°and 90°,fractures predominantly penetrated laminae without deflection;Below 60°,fractures initially diverted into the vein but subsequently re-entered the matrix before reaching the vein terminus.This bifurcation pattern closely resembles laboratory observations of weakly cemented or pre-damaged vein specimens.
Dubo Wang;Jinyu Dong;Dongqiao Liu;Xiangjun Chen;Hai Zhong;Mijia Yang;Hongjian Wang
North China University of Water Resources and Electric Power,Zhengzhou,450045,China Henan Key Laboratory of Geological Environment Intelligent Monitoring and Disaster Prevention,Zhengzhou,450045,ChinaNorth China University of Water Resources and Electric Power,Zhengzhou,450045,China Henan Key Laboratory of Geological Environment Intelligent Monitoring and Disaster Prevention,Zhengzhou,450045,ChinaState Key Laboratory of Intelligent Coal Mining and Strata Control,Beijing,100020,ChinaState Key Laboratory for Tunnel Engineering,China University of Mining and Technology,Beijing,100083,ChinaSchool of civil Engineering,Sanming University,Sanming,365004,ChinaConstruction and Environmental Engineering,North Dakota State University,Fargo,ND,58108,USANorth China University of Water Resources and Electric Power,Zhengzhou,450045,China Henan Key Laboratory of Geological Environment Intelligent Monitoring and Disaster Prevention,Zhengzhou,450045,China Henan Polytechnic University,Jiaozuo,454003,China
能源科技
ShaleInteractionFracture diversion distanceDiscrete element method(DEM)Semi-circular bend(SCB)test
《Rock Mechanics Bulletin》 2026 (2)
P.136-147,12
funded by the Open Funding of State Key Laboratory of Intelligent Coal Mining and Strata Control(SKLIS202421)Henan Key Research and Development Program of China(No.241111322900,241111321100)Educational Research Program for Young and Middle-aged teachers of Fujian Province of China(JAT210425/B202106)Young Backbone Teachers of Undergraduate Colleges in Henan Province(2023GGJS077)。
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