井口防喷器闸板轴结构优化分析  

Structural optimization on ram shaft of wellhead blowout preventer

作　　者：王浩华 秦浩 贾锦秀[3] WANG Haohua;QIN Hao;JIA Jinxiu(School of Energy and Power Engineering,Xihua University,Chengdu,Sichuan 610039,China;Key Laboratory of Fluid and Pow-er Machinery,Ministry of Education,Xihua University,Chengdu,Sichuan 610039,China;Bureau of Geophysical Prospecting South-west Geophysical Company,Chengdu,Sichuan 610213,China)

机构地区：[1]西华大学能源与动力工程学院,四川成都610039 [2]西华大学流体及动力机械教育部重点实验室,四川成都610039 [3]中国石油集团东方地球物理勘探公司西南物探分公司,四川成都610213

出　　处：《天然气技术与经济》2021年第4期46-51,共6页Natural Gas Technology and Economy

摘　　要：为了充分认识和准确掌握井口防喷器闸板轴在工作状态时轴身受力变形状况、为合理改善防喷器闸板轴轴端的超大受力情况提供理论参考,以国内石油天然气钻井工程中使用的井口防喷器(U形)闸板轴为研究对象,基于弹性力学对闸板轴进行有限元分析,分析了闸板轴轴身受力情况,明确了轴身应力集中位置,并对其进行结构优化。研究结果表明:①应力集中位于轴受力部件端部轴肩处;②轴端部周向膨胀受力为轴身圆周上的最大受力方向。可以通过改变应力集中区过渡圆角半径来降低轴肩处应力集中现象,同时提出增大轴端部直径来降低各项应力的认识;③未改变尺寸的最优设计,等效应力降低了23.7%,改变尺寸后的设计,等效应力降低了61.9%,周向应力应变分别降低了49.7%、48.7%;④水平轴在其平行力的作用下,轴身周向膨胀受力最大,该力对受压圆柱杆件表面的脆性涂层有很大的破坏力。结论认为,改进后的设计大大降低了轴端部表面各项应力,同时减小了喷涂层的周向受力、提高了涂层自身稳定性、增加了防喷器的使用寿命。In order to well know the deformation of the ram shaft of wellhead blowout preventer(BOP)under stress in the process of operation and provide theoretical reference for reasonable improving the shaft-end overload,the ram shaft of wellhead BOP(U type)applied to drilling engineering in domestic oil and gas wells was taken as an objective to analyze its finite element based on elasticity mechanics.And the ram-shaft stress was analyzed,the stress concentration positions on the shaft were pointed out,and ram-shaft structure was optimized.Results show that(1)stress concentrates at the shaft shoulder at the end of load bearing part;(2)the circumferential expansion force on the shaft end is the maximum stress di⁃rection around the shaft.It is recommended to alleviate this stress concentration at the shaft shoulder by changing the tran⁃sitional fillet radius of stress concentration zone and to reduce all stress by increasing the shaft-end diameter;(3)the equivalent stress in the optimal design with the same size drops by 23.7%.Whereas the equivalent stress,circumferential stress,and circumferential strain in the design with modified size drop by 61.9%,49.7%and 48.7%,respectively;and(4)when a horizontal shaft is under parallel force,its circumferential expansion force is the maximum and may bring great damage to brittle coating on the surface of load-bearing cylindrical rod.It’s concluded that the modified design may de⁃crease all stress on the shaft-end surface greatly while reducing the circumferential stress on the coating,so as to improve stability and service life for coating and BOP.

关 键 词：井口防喷器 闸板轴 弹性力学 应力集中 等效应力 周向应力应变 

分 类 号：TE921.5[石油与天然气工程—石油机械设备]