2016年2月
第41卷第2期
DOI;10. 3969/j. issn. 02540150. 2016. 02.023
润滑与密封
LUBRICATION ENGINEERING
常规液压钳钳牙对防腐蚀合金套管磨损破坏行为分析
徐建宁周欣
（西安石油大学机械工程学院陕西西安710065）
Feb.2016 Vol. 41 No. 2
摘要：目前油田普遍采用的防腐蚀合金（CRA）套管材质较软，工作时常规动力钳易破坏管两端处的表面镀锌层，加速硫化氢对套管的腐蚀。为减轻液压管钳对套管损伤，减缓硫化氢对套管的腐蚀，基于普通液压管钳工作原理，建立钳口力学模型，确定影响管钳加紧的具体因索。根据摩擦疲劳学理论，分析钳牙对套管的磨损成因和磨损过程，通过钳牙与油管上卸扣实验发现，磨损与接触区域、循环次数、相互接触材料等因素有明显关系。通过分析接触区域的应力应变，表明影响错牙对套管的磨损的主要因素是摩擦因数、接触载荷，并且摩擦因数对拉伸应变的影响更
e
加明显。
关键词：硫化氢腐蚀；套管；液压管钳；钳牙；摩擦损伤
中图分类号：TH117.1文献标志码：B文章编号：0254-0150（2016）02-116-05
BehaviorAnalysisofCorrosionResistantAlloysCasingWearDamage
by Clamp Jaws of Conventional Hydraulic Tongs
XUJianningZHOUXin
(School of Mechanical Engineering,Xi'an Shiyou University,Xi'an Shaanxi 710065,China)
e
Abstract:The galvanized layer on both ends of the corrosion resistant alloys (CRA) casing surface is easily to be dam aged by the conventional power tongs during working for the material of CRA casing usually used in the oil field is relative-ly soft,which willaccelerate the hydrogen sulfide corrosion of the casing.In order to reducing the damage of hydraulic tongs on casing,and slow down the corosion of hydrogen sulfide on casing,based on the working principle of the conventional hydraulic power tongs,the mechanics model of jaws was set up,and the specific factors affecting tongs tightening were de-termined.According to the tribological theory of fatigue, causes and process of wear of the casing by jaws were analyzed. Through the experiments of screw-on-off by the jaws on oil pipe,the result shows that wear has obvious relationship with contact area,number of cycles,the mutual contact materials and other factors.Through the stress and strain analysis of con tact area,it is shown that friction coefficient and contact load are the major factors influencing the casing wear by jaws,and the friction coefficient has more obvious influence on tensile strain.
Keywords:hydrogen sulfide corrosion ;casing;hydraulic tongs;jaws;friction damage
我国油田的开发目前已进人中后期，为应对硫化氢严重腐蚀套管的问题，油田已陆续将处在腐蚀区域的普通套管更换为合金套管和双防硫套管。防腐蚀的合金套管（CRA）材质较软，油井上在使用常规动力钳拆装管子的过程中，套管两端处被啃上深深的啮痕，表面锻锌层被完全破坏，加速硫化氢对套管的膜
蚀[1-2]，缩短套管的使用寿命。收稿日期：2015-04~30
作者简介：徐建宁（1963一），男，教投，硕士生导师，研究方向为先进采油装备设计及应用、机采油工作行为分析，
通讯作者：周欣（1989一—），男，硕土研究生，研究方向为石油钻采机械设计和行为分析.E-mail：zhouxin1204@126.com.
本文作者基于常规液压管钳结构，研究其对 CRA套管的磨损成因和磨损过程，利用摩擦疲劳学理论，分析其力学行为，为减轻液压管钳对套管损
伤，减缓硫化氢对套管的腐蚀提供理论依据。 1管钳工作原理
如图1所示，液压钳在卸扣的过程中，当开始上扣时，板架在制动盘的作用下保持静止，闭口齿轮通过液压动力带动旋转[3]。当闭口齿轮旋转时，固定在闭口齿轮内圆柱面上对称布置的坡板开始挤压颚板内滚轮，迫使颚板向板架的矩形槽内中心滑动。在坡板曲面约束下，闭口齿轮转动的同时造成坡板推动颗板向中心运动，最后触及管径外表面，压迫、挤压钳牙咬紧套管。