气候变化领域集成服务门户(CCPortal): Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling

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DOI	10.1029/2020JB020656
	Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling
	Chemenda A.I.; Lamarche J.; Matonti C.; Bazalgette L.; Richard P.
发表日期	2021
ISSN	21699313
卷号	126 期号:3
英文摘要	Fracturing (jointing) affects large volumes of rocks and strongly impacts their mechanical stability and permeability. In layered sedimentary basins, the fractures typically form subparallel sets with different fracture spacing S. This parameter has been extensively studied both in the field and in mechanical models in relation to the thickness T of the fractured layers. A linear relation was suggested by most studies. A few geological investigations involving wide ranges of T values have shown that the T(S) relation is generally strongly nonlinear and that in thick beds (T >∼1.5 m), S practically does not depend on T. The origin of this relation remained hitherto unexplained. Here we obtained such a relation in 2-D finite-difference models of 3-layer sedimentary sequences where layers interact through the interfaces of strength R. The middle layer has elastoplastic properties with coupled tensile and shear failure mechanisms. The number of fractures forming in this layer increases under horizontal extension to a saturation value S depending on R. At T < ∼0.5 m, the increase of S with T is near-linear. At ∼1 m < T < 2 m, it is strongly nonlinear; and S changes little at larger T where S is more than certain value Scr. The increase of ratio D = T/S with T is, on the contrary, close to linear. This behavior is explained by the fact that for D >∼2, the stress state in the upper and lower horizons of the middle layer between fractures spaced 2Scr apart is practically independent of T. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	dilation bands; elastoplastic modeling; fracture spacing; fracturing; joints; sedimentary basins
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187262
作者单位	Université Côte d’Azur, Observatoire de la Côte d'Azur, CNRS, IRD, Géoazur, Valbonne, France; Aix-Marseille University, CNRS, IRD, INRAE, Collège France, CEREGE, Aix-en-Provence, France; Petroleum Development Oman (PDO), Field Development Centre, Mina al Fahal, Oman; Shell Global Solutions International BV, Rijswijk, Netherlands
推荐引用方式 GB/T 7714	Chemenda A.I.,Lamarche J.,Matonti C.,et al. Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling[J],2021,126(3).
APA	Chemenda A.I.,Lamarche J.,Matonti C.,Bazalgette L.,&Richard P..(2021).Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling.Journal of Geophysical Research: Solid Earth,126(3).
MLA	Chemenda A.I.,et al."Origin of Strong Nonlinear Dependence of Fracture (Joint) Spacing on Bed Thickness in Layered Rocks: Mechanical Analysis and Modeling".Journal of Geophysical Research: Solid Earth 126.3(2021).