水平井层内爆炸裂缝体模拟研究  

Research on Stimulated Reservoir Volume with Exploding in Horizontal Well-Bore

作　　者：刘长印[1] 孙志宇[1] 张汝生[1] 李宗田[1] 

机构地区：[1]中国石油化工股份有限公司石油勘探开发研究院,北京100083

出　　处：《油气井测试》2014年第6期4-8,73,共5页Well Testing

基　　金：国家科技重大专项"大型油气田及煤层气开发"中的课题"中西部地区碎屑岩储层预测;保护与改造技术研究"(2011ZX05002-005)的内容

摘　　要：水平井层内爆炸是一动态裂缝扩展过程,涉及到被爆岩石、炸药及边界条件各系统之间相互作用关系。基于有限元分析方法及其单元消除技术,应用线弹性断裂力学理论中平面应力—位移关系方程及最大拉应力脆性断裂准则方程,建立了适用于水平井层内爆炸裂缝体模拟数学模型。通过对水平井筒内瞬时爆炸载荷分布规律的描述、模型区域的选取、初始地应力场的施加、远场边界条件的设定、单元类型与尺寸的选择及高载荷速率下形成的奇异解的处理,并考虑应力波在岩石中的传播、阻尼影响,可以利用ABAQUS有限元计算工具对该方程所在的爆炸冲击模块中进行动态显式方法求解。数值模拟结果可以得到一定条件下水平井筒层内爆炸产生的裂缝体几何形态,分析不同地应力大小、地应力各向异性、岩石力学特征及不同炸药性能对裂缝形态及几何尺寸的影响。该研究结果可以揭示水平井层内爆炸裂缝体延伸规律及其主要控制因素,有利于提高爆炸能量的利用率,对现场施工方案设计及效果分析具有一定的理论指导意义。The process of exploding in horizontal well-bore is a dynamic fractures initiation and propagation and three main systems involved in the study,namely,rock,explosive and boundary conditions. Based on the model of finite element software package,applying element elimination technique and stress-displacement correlation equation of linear elastic fracture mechanics theories,the numerical model of explosive loading in horizontal well-bore has been established. By appropriate numerical description for explosion pressure-time profile in horizontal well-bore,selection of rock crack failure criterion,loading of initial in-situation stress,determination of far-field boundary conditions,resolving singularity problem resulted by high loading pressure rate and consideration of stress wave propagation and damping in the rock,the equation can be resolve d by explicit ABAQUS methods. The numerical modeling results can show the fracture geometry caused by exploding in horizontal well-bore in certain circumstance,and analysis the effect of different in-situ stress,stress anisotropy,rock mechanics and explosive properties on fractured reservoir volumes,which can display the major factors control the process of exploding in horizootal well-bore,and provide theoretically conductive significance in fracturing design and post-fracture evaluation.

关 键 词：水平井 层内爆炸 裂缝体 模拟 研究 有限元 

分 类 号：TE357[石油与天然气工程—油气田开发工程]