西南石油大学学报(自然科学版)

• 油气化学工程 • 上一篇    下一篇

橡胶O 型圈耐CO2 腐蚀测试及适用性评价

曾德智1,李坛1,雷正义2,曹大勇3,施太和1   

  1. 1.“油气藏地质及开发工程”国家重点实验室西南石油大学,四川成都610500
    2. 中国石油吉林油田公司钻采工程部,吉林松原138000;3. 中国航天科技集团公司川南机械厂,四川泸州646000
  • 出版日期:2014-04-01 发布日期:2014-04-01
  • 基金资助:

    国家自然科学基金(51374177,51004084)。

CO2 Corrosion Resistance Test and Applicability Evaluation
of Rubber O-ring

Zeng Dezhi1, Li Tan1, Lei Zhengyi2, Cao Dayong3, Shi Taihe1   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China
    2. Jilin Oilfield Company,PetroChina,Songyuan,Jilin 138000,China
  • Online:2014-04-01 Published:2014-04-01

摘要:

在高含CO2 油气田作业中,橡胶O 型圈的适用性对油气田的生产安全具有一定影响。以往橡胶O 型圈的相
关研究只是在自由状态,而在实际工况下,橡胶O 型圈通常处于压应力状态。为此,自行设计了一种检测承压状态下
橡胶密封件耐腐蚀和密封性能的装置,在压力为35 MPa、温度为140 ℃、气相组成为5%CO2 和95%N2 的环境中,对4
种橡胶材料的O 型圈进行了耐CO2 腐蚀实验。通过比较它们在腐蚀前后物理性能和形貌的变化,对其在此环境中的
适用性做出了评价。研究发现,腐蚀后O 型圈的物理性能下降;在承压状态下的腐蚀程度比自由状态下弱,并且,在
承压状态下,液相腐蚀比气相腐蚀弱,而自由状态下则相反;腐蚀后O 型圈发生溶胀老化等现象,引起密封失效。此
项研究为高温高压高含CO2 油气田上油气井橡胶密封件的选材和使用提供了参考依据。

关键词: 橡胶O 型圈, CO2, 腐蚀, 压应力状态, 适用性评价

Abstract:

In the high CO2 oil and gas field operations,the applicability of rubber O-ring has a certain effect on the production
safety. Previous studies related to the rubber O-ring is merely in a free state,but in the actual operating condition,the rubber
O-ring is mostly in a compressive stress state. Therefore,we designed a new device for corrosion resistance and sealing property
test of rubber seals in a compressive stress state,in the harsh environment with pressure of 35 MPa,temperature of 140 ℃,gas
phase composition of 5%CO2 and 95%N2,and the CO2 corrosion resistance experiments on the O-rings of four kinds of rubber
materials were conducted. Through comparing the mechanical properties and morphology changes before and after corrosion,
the applicability evaluation of them in the above experiment environments was made. The study found that the mechanical
properties of O-rings after corrosion decreased. The corrosion extent of O-rings was weaker in the compressive stress state than
in the free state,and in the compressive stress state,the liquid corrosion was weaker than the gaseous corrosion,but stronger
in the free state. After corrosion the swelling and aging of O-rings occurred,which caused the seal failure. The study provided
references for the selection and use of rubber seals in the high temperature and high pressure oil and gas field with high CO2
content.

Key words: rubber O-ring, CO2, corrosion, compressive stress state, applicability evaluation