大膨胀率实体膨胀管膨胀载荷的塑性力学计算  

Plastic Mechanics Calculations of Expansion Load of Large-expansion-rate Expandable Solid Tubular

作　　者：张丛雷 李春福[1] 张凤春[1] 申文竹[1] 宋开红[2] 王燕群[3] 

机构地区：[1]西南石油大学油气藏地质与开发工程国家重点实验室 [2]中国石油天然气股份有限公司大港油田分公司 [3]天津大学机械工程学院

出　　处：《石油机械》2014年第7期1-6,共6页China Petroleum Machinery

基　　金：国家863计划项目"膨胀管钻井技术"(2006AA06A105)

摘　　要：已有的可膨胀管膨胀模型的力学分析和载荷计算多数建立在弹塑性力学基础上,忽略了套管材料在塑性阶段的应力强化效应,以及膨胀区向定径区过渡时的管体弯曲对轴向应力增量的影响。鉴于此,在已有模型的基础上,采用单一曲线假设和幂强化力学模型,建立了大膨胀率膨胀管膨胀载荷的力学模型,运用ANSYS Workbench14.5建立了膨胀管膨胀过程的三维轴对称模型,并进行了大膨胀率膨胀管膨胀载荷计算。研究结果表明,当膨胀率在15%～30%之间变化、膨胀力最优半锥角在12°～22°之间变化时,所需膨胀力最小;当其他参数恒定,摩擦因数、管半径、壁厚和膨胀率中任一个作为自变量时,膨胀力与该自变量呈线性递增关系。因此,选择合适的摩擦因数、膨胀率和壁厚对降低膨胀管施工难度相当重要;膨胀管应选择强化系数相对较小、硬化指数较大的管材,这样膨胀时所需膨胀力较小。The existing expansion models of expandable solid tubular for mechanical analysis and load calculations are mostly based on the elastic-plastic mechanics, which ignore the casing stress strengthening effect at plastic stage and the casing bending effect on the axial stress increment where expansion area transits to sizing area. To address these problems, a mechanics model of expansion load of large-expansion-rate expandable solid tubular is established based on the single-curve assumption and power hardening mechanical model. A three-dimensional axisym- metric model of expandable solid tubular during expansion process is also established by using ANSYS Workbenchl4. 5 and the expansion force is calculated. The results show that minimum expansion force is required when the expansion rate varies from 15% to 30% and the optimal expansion force half cone angle varies from 12° - 22°. While other parameters are constant, with the increment of friction factor, tubular radius, wall thickness and expansion rate, the expansion force increases linearly. Therefore, appropriate friction factor, expansion rate and wall thickness is critical to reduce the expansion operation difficulty. Expandable solid tubular should choose tubular with small strengthening factor and large hardening exponent to reduce the required expansion force.

关 键 词：大膨胀率 实体膨胀管 膨胀力 幂强化力学模型 最优膨胀锥角 

分 类 号：TE256[石油与天然气工程—油气井工程]