含有硬包裹体分布的非均质岩石水力压裂特性研究

发布时间：2018-03-13 08:53

本文选题：水力压裂　切入点：弥散裂缝模型　出处：《岩土力学》2016年11期 　论文类型：期刊论文

【摘要】：基于完全流-固耦合的弹塑性理论给出了水力压裂数值计算的弥散裂缝模型,其中材料的弹性部分采用线弹性本构关系,塑性部分采用摩尔-库仑破坏准则及强化准则。依据当前的有效应力状态修正渗透系数来模拟压裂液在裂缝中的流动。渗透系数的修改使用双曲正切函数,并采用平均有效应力作为水力裂缝的起裂判据。在ABAQUS软件中通过用户自定义程序添加了该模型。根据岩石的切面照片建立了含有硬包裹体分布的非均质岩石的有限元计算模型,模拟了中心点注水条件下的水力压裂传播过程,讨论了在常应力状态下非均质岩石中开裂区域、典型位置的应力路径变化和裂缝传播范围随时间变化的特点。进行了多种条件下含有硬包裹体分布的岩石材料的数值试验,得出了基岩材料的弹性模量、凝聚力和渗透系数以及注水速率对峰值注水压力、平均注水压力和裂缝开度的影响规律。
[Abstract]:Based on the elastic-plastic theory of complete fluid-solid coupling, the dispersion fracture model for numerical calculation of hydraulic fracturing is presented, in which the elastic part of the material is linear elastic constitutive relation. Mohr Coulomb failure criterion and strengthening criterion are adopted in the plastic part. The flow of fracturing fluid in fracture is simulated according to the current effective stress state modified permeability coefficient. The permeability coefficient is modified by hyperbolic tangent function. The average effective stress is used as the fracture initiation criterion of hydraulic fractures. The model is added to the software ABAQUS by the user-defined program. The finite element calculation model of heterogeneous rock with hard inclusion distribution is established according to the cut plane photographs of the rock. The process of hydraulic fracturing propagation under the condition of water injection at the center point is simulated, and the crack area in heterogeneous rock under constant stress is discussed. The variation of stress path in typical position and the variation of crack propagation range with time. Numerical tests of rock materials with hard inclusion distribution under various conditions have been carried out, and the elastic modulus of bedrock materials has been obtained. The effect of cohesion, permeability coefficient and injection rate on peak water injection pressure, average water injection pressure and fracture opening.
【作者单位】：东北大学土木工程系;麦克马斯特大学土木工程系;
【基金】：教育部项目基本科研业务费项目(No.N110301001);教育部项目博士点基金(No.20120042110001) 国家自然科学基金资助项目(No.51474048)~~
【分类号】：TU45

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