计算力学学报2018，Vol.35Issue(1)：91-97,7.DOI:10.7511/jslx20161102001
多簇压裂干扰应力变化规律及对裂纹扩展的影响
Law of induced stress in multi-cluster fracturing and the effect on crack propagation
摘要
Abstract
In order to study the induced stresses in multi-cluster cracks of horizontal wells and their effects on crack propagation,an analytical solution of 3D induced stresses considering in-situ stresses was established by double plane complex variable function conformal transformation based on 2D induced stress solutions without in-situ stress.A 3D multiple-crack propagation parametric numerical simulation was realized by Abaqus/Python and the extended finite element method.This research drew the following conclusions through analytical derivation and numerical analysis.The induced stresses beside on the crack faces have vertical compressive stress and tangential tensile stress and both are spindle shaped.The vertical induced stress influence range is about 5 times of the tangential.In contrast,the induced stresses around a crack tip have vertical tensile stress and tangential compressive stress.The induced shear stress appears beside a crack tip.The modified analytical solution of streeses after taking in-situ stress into consideration becomes lower.The induced stresses add up in multi-cluster fracturing and the combined effects get stronger along the cluster space crack.The superposed induced stresses make the crack expand and fluid pressure rise and the crack opening reduces which restricts the propogation of a single crack.The induced stress effects reduce the stress difference and change the dreictions of the minimum stresses at some positions,which can promote formation crack network.关键词
多簇压裂/复变函数/干扰应力/地应力/解析解/裂纹扩展/扩展有限元法Key words
multi-cluster fracturing/complex variable function/induced stresses/in-situ stress/analytical solutions/fracture propagation/XFEM分类
能源科技引用本文复制引用
孙可明,张树翠..多簇压裂干扰应力变化规律及对裂纹扩展的影响[J].计算力学学报,2018,35(1):91-97,7.基金项目
国家自然科学基金(51574137)资助项目. （51574137）
