石油学报 ›› 2019, Vol. 40 ›› Issue (2): 232-239.DOI: 10.7623/syxb201902012

• 石油工程 • 上一篇    下一篇

气井生产过程中碳钢管柱CO2腐蚀规律

赵垒1,2, 闫怡飞1,2, 王鹏3, 张庆生4, 宋胜利4, 赵龙1,2, 韩伟民2, 冯耀荣3, 闫相祯1,2   

  1. 1. 中国石油大学(华东)机电工程学院 山东青岛 266580;
    2. 中国石油大学(华东)油气CAE技术研究中心 山东青岛 266580;
    3. 中国石油天然气集团公司管材研究所 陕西西安 710065;
    4. 中国石油化工股份有限公司中原油田分公司石油工程技术研究院 河南濮阳 457000
  • 收稿日期:2017-11-26 修回日期:2018-11-20 出版日期:2019-02-25 发布日期:2019-03-05
  • 通讯作者: 闫怡飞,男,1984年11月生,2010年获北京航空航天大学学士学位,2016年获中国石油大学(华东)博士学位,现为中国石油大学(华东)机电工程学院讲师,主要从事油气安全工程方面的教学与科研工作。Email:yanyf163@163.com
  • 作者简介:赵垒,男,1987年5月生,2011年获安徽新华学院学士学位,现为中国石油大学(华东)博士研究生,主要从事油气安全工程方面的研究。 Email:zhaoleixh3a@163.com
  • 基金资助:

    国家自然科学基金项目(No.51804330);国家科技重大专项(2016ZX05017-003);中国石油天然气集团公司科技计划项目(2016A-3905)和中央高校基本科研业务费专项资金项目(18CX02154A)资助

CO2 corrosion law of carbon steel tubing string in the production process of gas well

Zhao Lei1,2, Yan Yifei1,2, Wang Peng3, Zhang Qingsheng4, Song Shengli4, Zhao Long1,2, Han Weimin2, Feng Yaorong3, Yan Xiangzhen1,2   

  1. 1. School of Mechanical and Electronic Engineering, China University of Petroleum, Shandong Qingdao 266580, China;
    2. Qil & Gas CAE Technology Research Center, China University of Petroleum, Shandong Qingdao 266580, China;
    3. Tubular Goods Research Center of China National Petroleum Corporation, Shaanxi Xi'an 710065, China;
    4. Petroleum Engineering Technology Research Institute, Sinopec Zhongyuan Oilfield Company, Henan Puyang 457000, China
  • Received:2017-11-26 Revised:2018-11-20 Online:2019-02-25 Published:2019-03-05

摘要:

掌握气井稳态生产过程中CO2对碳钢管柱沿井深方向的腐蚀规律才能更好地确定油气田开发和实施方案,预防和降低管柱腐蚀失效事故。根据质量守恒、动量守恒、能量守恒以及非理想气体状态方程建立了地面稳态生产条件下管柱内热流耦合计算模型,并与实测结果进行了对比研究。以Norsok模型为基础,根据实际生产用管材等建立了相应的修正表达式,并进行了实例验证。研究了CO2摩尔分数、井筒总体传热系数,管柱内半径和日产量对管柱腐蚀速率的影响。研究表明,建立的热流耦合模型和腐蚀预测模型计算精度满足工程需要;地面日产量越大,井深方向管柱内天然气密度、速度、温度越高,而压力越低;增加CO2摩尔分数和地面日产气量、降低井筒总体传热系数和管柱内径均可引起管柱最大腐蚀速率出现的位置向井口方向移动,并且日产气量和井筒总体传热系数的影响更为明显;沿井深方向上,管柱腐蚀速率变化分为4个阶段,且不同影响参数变化时,腐蚀速率的影响规律不尽相同。

关键词: 气井, 稳态生产, 碳钢管柱, CO2腐蚀, 腐蚀规律

Abstract:

The CO2 corrosion law for carbon steel tubing string along the wellbore depth direction in the steady-state production process of gas well is studied to better determine the development and implementation scheme of oil and gas field, prevent and reduce tubing string corrosion failure accidents. In this study, a thermal-flow coupling model in tubing string during steady production process is established on the bases of the mass conservation, momentum conservation, energy conservation and non-ideal gas state equations, and the results from the model are compared with the measured data. A corresponding amendment expression is built based on the Norsok model, actual tubing string materials and so on, and an example is provided to prove its validity. The effects of CO2 mole fraction, total heat transfer coefficient of wellbore, tubing string inner diameter and daily gas production rate on the corrosion rate of tubing string are studied, and the results show that the calculation precision of coupling model and corrosion prediction model is able to satisfy the engineering requirement. The larger the daily gas production on the ground is, the higher the density, velocity and temperature of natural gas in tubing string along the well depth direction will be, but the lower the pressure will be. Increasing the mole fraction of CO2 and surface daily gas production as well as decreasing the total heat transfer coefficient of wellbore and inner diameter of tubing string can both lead to the occurrence position of maximum corrosion rate in tubing string moving towards wellhead, and the effects of daily gas production and total heat transfer coefficient of wellbore are more obvious. The variation of tubing string corrosion rate can be divided into four stages along the wellbore depth, and the influence law of corrosion rate varies with different impact parameters.

Key words: gas well, steady-state production, carbon steel tubing string, CO2 corrosion, corrosion law

中图分类号: