钻杆加厚过渡带几何尺寸的优化选择

钻杆刺漏大都发生在钻杆加厚过渡带消失处，优化选择钻杆加厚过渡带几何尺寸是重要的措施。没有使用常规方法对过渡带进行模拟以研究应力集中系数，而是在有限元中分别观察钻杆内壁和外壁液体流场速度、节点压力等数值的变化，同时改变钻杆加厚过渡带各几何参数，综合考虑流体速度和节点压力场分布，推荐出钻杆加厚过渡带几何尺寸最优组合。

The Optimized Choice of the Geometric Shape in Intermediate Belt

The drill pipes in some oil fields were diapired badly and continually and the diapiric happened to the intermediate belt's disappearance of drill pipes.So,we think that it is essential to study the geometric shape in intermediate belt.In this paper we don't use a normal way to simulate the intermediate belt for studying the stress concentration factor.We observe the liquid of drill pipes' inner and exterior by the finite element method and get their velocity and pressure etc.with changing geometric parameter.The velocity and pressure are considered synthetically.At last,we get the best geometric combination.