流固耦合理论在船体总振动附加水质量研究中的应用

基于流固耦合理论对采用刘易斯方法求得的船体总振动固有频率进行了修正,给出了修正系数,并且对流固耦合计算中流体单元范围的选取进行了计算和讨论,可提高船体总振动预报的效率和准确度.     

斜井眼内钻柱轴向振动的有限元分析

在斜井眼（弯曲井眼）钻进过程中．钻柱存在各种振动行为，其中跳钻是制约斜井钻进的主要因素之一．跳钻是由于钻柱轴向强烈振动引起的。严重跳钻现象表明斜井眼内钻柱的轴向振动是不能忽略的。以斜井眼的钻柱整体为研究对象．分析了钻柱整体在周期性激振力存在情况下轴向动态行为所遵循的规律。采用有限元法，对钻柱整体进行了分析，获得了钻柱整体的质量和刚度矩阵．进一步获得了动力学矩阵方程，并编制了计算程序．计算出了钻柱轴向振动的固有频率．结果表明受迫振动频率与钻柱固有频率接近时出现跳钻现象。这为深入研究斜井眼内钻柱动态行为提供了理论依据，并为进一步分析大位移井钻柱振动奠定了理论基础．具有现实的指导意义。     

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本文介绍了有限单元法的基本原理和计算方法,提出用此法计算地质历史时期构造应力场的一般步骤,举例说明构造应力场对碳酸盐岩中裂缝发育的影响,分析了该法预测裂缝的效果,为合理勘探裂缝性气藏提供一种新的研究手段。     

用有限元法进行抽油机的运动及动力分析

在考虑弹性变形的情况下，采用有限元技术对抽油机进行了运动和动力分析。通过单元和整体分析，给出了抽油机四杆机构的系统运动方程；总结了用有限元法分析抽油机四杆机构的步骤为：结构离散；单元计算；强迫力矩阵计算；单元刚度和质量矩阵迭加；系统方程求解。最后给出了ＣＹＪ１６Ｑ—３．６—７４Ｂ前置式抽油机的分析计算实例。     

基于有限元法对带接管压力容器的可靠性分析

运用ANSYS的可靠性分析功能,对带接管压力容器的可靠性进行数值模拟,得出容器的可靠度、峰值应力的概率分布、设计参数的灵敏度等信息。通过与可靠度的公式计算结果进行对比,得出模拟结果能更直观地反映实际可靠度。     

电阻率成象测井有限元分析

电阻率成象测井是石油测井中最新一代的测井方法。对测井仪器响应的精确模拟，可以为此类仪器的优化设计和资料解释提供依据。针对电阻率成象仪的激励条件比较复杂以及井下地层的非均质性，选用适于处理复杂条件问题的三维有限元方法对仪器产生的位场进行分析；基于电阻率成象仪器的测量原理，给出了利用有限元分析得到视电阻率的方法；通过对水平、倾斜等典型地层模型的数值模拟测量，得出相应的电阻率井壁成象结果，从而直观地反映井壁地层特征。     

基于有限元的膨胀管膨胀过程力学分析

为了研究膨胀管在膨胀过程中的力值分布、膨胀管外形尺寸的变化,以及管内的残余应力分布,对膨胀管和膨胀锥进行三维建模.通过ANSYS软件对膨胀过程进行有限元分析,得到膨胀管的应力分布、膨胀力值、残余应力、轴向收缩量以及壁厚变化情况.为现场施工提供理论指导.     

基于C语言的钻柱有限元单元刚度矩阵计算

单元刚度矩阵的建立是有限元分析中的一个重要步骤。就实际钻柱受力与变形分析中出现的20节点六面体单元进行研究,给出了计算单元刚度矩阵的方法和步骤,并运用C语言编写了相应程序,为解决大型三维有限元问题提供了较好的思路。     

Simulation of Solid Tubular Expansion in Well Drilling Using Finite Element Method

Solid expandable tubular is an emerging and promising technology in petroleum industry. It consists of increasing the diameter of a tubular by hydraulically pushing or mechanically pulling a conical mandrel through it. In this paper, a dy namic explicit finite element analysis (FEA) has been used to study the solid tubular expansion using ABAQUS, a commercial FEA software package. The required drawing force for tubular expansion was estimated for different mandrel shapes, friction coefficients, and expansion ratios. The drawing force increases with the increase in friction coefficient and expansion ratio. It was also found that the material velocities increase on the front of the mandrel but decrease to zero in the post expansion section. Moreover, the plastic deformation shows a reduction of thickness with friction coefficient and expansion ratio. Simulation results also revealed that contact occurs at the two ends of the conical mandrel tubular interface and that the contact stress increases with friction coefficient reaches to maximum value at an expansion ratio of 20%.     

Simulation of Solid Tubular Expansion in Well Drilling Using Finite Element Method

Abstract

Solid expandable tubular is an emerging and promising technology in petroleum industry. It consists of increasing the diameter of a tubular by hydraulically pushing or mechanically pulling a conical mandrel through it. In this paper, a dy namic explicit finite element analysis (FEA) has been used to study the solid tubular expansion using ABAQUS, a commercial FEA software package. The required drawing force for tubular expansion was estimated for different mandrel shapes, friction coefficients, and expansion ratios. The drawing force increases with the increase in friction coefficient and expansion ratio. It was also found that the material velocities increase on the front of the mandrel but decrease to zero in the post expansion section. Moreover, the plastic deformation shows a reduction of thickness with friction coefficient and expansion ratio. Simulation results also revealed that contact occurs at the two ends of the conical mandrel tubular interface and that the contact stress increases with friction coefficient reaches to maximum value at an expansion ratio of 20%.