直井地面驱动螺杆泵采油杆管偏磨机理  

Mechanism of eccentric wear between rod string and tubing string of a surface driving screw pump lifting system in vertical wells

作　　者：董世民[1] 张万胜[1] 王强[1] 柴国鸿[1] 苏艳玲[1] 

机构地区：[1]燕山大学机械工程学院,河北秦皇岛066004

出　　处：《石油学报》2012年第2期304-309,共6页Acta Petrolei Sinica

基　　金：国家自然科学基金项目(No.50974108)资助

摘　　要：将直井地面驱动螺杆泵采油杆柱简化为在油管内偏心旋转的杆柱。考虑了杆柱偏心旋转惯性离心力、轴向力对杆柱横向弯曲变形的影响。应用可移动双向弹簧元模拟杆管接触状态,并考虑了杆体、结箍以及扶正器与油管间隙不同对杆柱挠度约束的差别,建立了螺杆泵采油杆柱在油管内受力变形的有限元仿真模型。仿真结果表明:抽油杆柱在油管内偏心旋转会产生陀螺效应,杆柱在油管内变形形态呈下密上疏的螺旋状,这是直井地面驱动螺杆泵采油系统杆管偏磨的主要原因之一。杆柱与油管接触段长度主要取决于转速、下泵深度和偏心距等参数。当转速较高时,几乎所有接箍均与油管内壁接触,也会出现杆体与油管内壁接触的现象。The rod string of a surface driving screw pump system in vertical wells can be simplified as an eccentric rotation rod string in the tubing string.In this case,effects of the axial force and inertial centrifugal force caused by eccentric rotation of a rod string on the lateral bending deformation of the rod string must be investigated.We employed removable biaxial spring elements to describe the contacting state between the rod string and tubing string,and a finite element simulation model for describing the deformation of a screw pump rod string in the tubing string was set up on condition that all the differences caused by different interspace between the rod body,coupling,centralizer and the tubing string in constraints on the bending deflection of a rod string have been taken into consideration.Simulation results demonstrate that the eccentric rotation of a rod string in the tubing string can produce a gyro effect that may lead to a lateral deformation of the rod string,and the deformed rod string is commonly in a helical shape with helixes decreasing upward,which is one of the major reasons to generate the eccentric wear between the rod string and tubing string of a surface driving screw pump system in vertical wells.The contacting length between the rod string and tubing string mainly depends on some operating parameters,such as rotation speed,putting-on depth of the pump,eccentricity,etc.With a higher rotation speed,almost all the couplings on the rod string will contact with internal walls of the tubing string,and the rod body may also touch internal walls of the tubing string occasionally.

关 键 词：地面驱动螺杆泵 抽油杆柱 偏心旋转 陀螺效应 偏磨机理 仿真模型 

分 类 号：TE833[石油与天然气工程—油气储运工程]