摘要
针对常规钻井液条件下使用的钻柱减振器在应用到空气钻井中暴露出的缺陷与不足,分析了一种针对气体钻井特点而设计的新型空气钻井减振器。建立了这种减振器传动轴的三维模型,运用有限元计算了传动轴的应力和位移分布。然后定义了随时间变化的载荷谱,利用雨流计数法对载荷谱进行了简化和转换,研究了变载荷作用下传动轴的疲劳情况。结果表明,减振器传动轴断裂机理是疲劳断裂;传动轴上花键与光轴的过渡区和花键齿根底部过渡圆角部位是疲劳的策源区;花键齿根底部过渡圆角曲率过小是引起传动轴疲劳断裂的基本原因。
In light of the weaknesses and imperfections exposed in the application of the drill string damper in ordinary drilling fluid conditions to air drilling, a new type of damper was analyzed which was designed according to the characteristics of air drilling. The three-dimensional model of the damper transmission shaft was established. The finite element method was adopted to calculate the stress and displacement distribution of the shaft. Then, the load spectrum which changes with time was defined. The rain-flow counting method was adopted to simplify and convert the load spectrum. The fatigue of the shaft under the effect of variable load was studied. The result shows that the fracture mechanism of the damper transmission shaft is of fracture caused by fatigue. The transition zone between the spline and the optical axis on the shaft and the transition fillet position at the bottom of the dedendum are the source zones of fatigue. The excessively little curvature of the transition fillet at the bottom of the spline dedendum is the basic reason for causing the fatigue fracture of the shaft.
出处
《石油机械》
北大核心
2011年第11期17-19,23,共4页
China Petroleum Machinery
基金
国家自然科学基金项目"基于数值模拟的复杂地层地应力反演研究"(50774063)
