石油学报 ›› 2021, Vol. 42 ›› Issue (5): 686-694.DOI: 10.7623/syxb202105012

• 石油工程 • 上一篇    下一篇

压差激活密封剂的微缺陷自适应修复行为及机理

许林1, 刘书杰2, 许明标3,4, 冯桓榰5, 邢希金5, 邓佳佳1   

  1. 1. 浙江海洋大学石油化工与环境学院 浙江舟山 316022;
    2. 中海石油(中国)有限公司湛江分公司 广东湛江 524057;
    3. 长江大学非常规油气湖北省协同创新中心 湖北武汉 430100;
    4. 荆州嘉华科技有限公司 湖北荆州 434000;
    5. 中海石油(中国)有限公司北京研究中心 北京 100028
  • 收稿日期:2019-10-26 修回日期:2021-01-12 出版日期:2021-05-25 发布日期:2021-06-05
  • 通讯作者: 许明标,男,1962年5月生,1983年获西南石油学院学士学位,2008年获中国地质大学(武汉)博士学位,现为长江大学石油工程学院教授,主要从事井筒工作液设计与开发方面研究。Email:xmb_62@163.com
  • 作者简介:许林,男,1979年12月生,2003年获江汉石油学院学士学位,2011年获浙江大学博士学位,现为浙江海洋大学海洋油气工程系副教授,主要从事油田化学、材料化学、计算化学等领域教学及研究工作。Email:xuhu_14@zjou.edu.cn
  • 基金资助:
    国家科技重大专项(2016ZX05060-015)、湖北省重点研发计划项目(2020BAB072)、浙江省基础公益研究计划项目(LGG20E040002)、舟山市科技计划项目(2019C21006)和中海油研究总院项目(YXKY-2017-ZY-09)资助。

Self-adaptive repair behavior and mechanism of micro-defects of differential pressure activated sealant

Xu Lin1, Liu Shujie2, Xu Mingbiao3,4, Feng Huanzhi5, Xing Xijin5, Deng Jiajia1   

  1. 1. School of Petrochemical Engineering & Environment, Zhejiang Ocean University, Zhejiang Zhoushan 316022, China;
    2. Zhanjiang Branch, CNOOC China Limited, Guangdong Zhanjiang 524057, China;
    3. Cooperative Innovation Center of Unconventional Oil and Gas, Yangtze University, Hubei Wuhan 430100, China;
    4. Jingzhou Jiahua Tech. Ltd., Hubei Jingzhou 434000, China;
    5. Beijing Research Center, CNOOC China Limited, Beijing 100028, China
  • Received:2019-10-26 Revised:2021-01-12 Online:2021-05-25 Published:2021-06-05

摘要: 压差激活密封剂是一种适用于油气井管柱微泄漏快速、安全修复的新技术,目前关于该体系的应用及理论研究报道较少。采用室内实验、结构表征、理论分析及数值模拟相结合的方法,开展了压差激活密封剂制备、微形貌检测、密封性能评价、压差激活机理分析、自适应密封动力学模拟等方面的应用基础研究。研究结果显示:制备的压差激活密封剂是一种多分散相体系,分散相为水化胶粒,具有微米级层状体型结构,是确保压差激活密封性能的关键组分;在5~15 MPa压差范围内,密封剂能够在150 s内穿透丝扣滑脱及漏缝孔隙形成韧性固体屏障,有效封堵不同类型微缺陷;基于水化胶粒的分子形态与稳定性间关系,提出了压差激活密封流体的液-固转化构效假设,建立了漏点压差的自适应密封力学-化学耦合模型;分析了复合液滴在环境液体压差下的受力状态,采用LES-VOF方法模拟了复合液滴在环境液体射流场的变形与破碎动力学行为,研究了水化胶粒的去水化动态演化过程,表层水化膜的射流变形显著大于胶核,可发生振荡破裂使胶核活化聚结,进而充填固化封堵微缺陷。模拟结果与理论分析基本一致,为进一步研究压差激活密封剂提供了理论支持。

关键词: 压差激活密封剂, 微缺陷, 自适应修复, 复合液滴, 射流变形, 力学-化学耦合模型, 数值模拟

Abstract: Differential pressure activated sealant is a new technology suitable for rapid and safe repair of micro leakage in tubular strings in oil and gas wells. There are few reports on the application and theoretical research of this system. Based on a combination of laboratory test, structural characterization, theoretical analysis and numerical simulation, this paper systematically carries out basic research for application in terms of preparation, micro-morphology detection, sealing property evaluation, mechanism analysis of differential pressure activation, as well as dynamics simulation of adaptive sealing. The research results show that the prepared differential pressure activated sealant is a polydisperse system; the dispersed phase is hydrated colloidal particles with micron-level layered physical conformation, which is a key component to ensure the sealing property of differential pressure activated sealant. Within the pressure differential range of 5-15 MPa, in 150 s, the sealant can penetrate the threaded dropout and leaky pores to form a tough solid barrier, which can effectively plug different types of micro-defects. Based on the relationship between the molecular morphology and stability of the hydrated colloidal particles, this paper proposes a hypothesis on the structure effect of liquid-solid transformation of differential pressure activated sealed fluid, and establishes an adaptive sealing mechanics-chemical coupling model of the differential pressure at the leaking point. Further, it analyzes the stress state of composite droplet under the differential pressure of environmental liquid, uses the LES-VOF method to simulate the dynamic behaviors of deformation and breaking of the composite droplet in the jet flow field of environmental liquid, explores the dynamic evolution process of the dehydration of hydrated colloidal particles. The jet deformation on the surface hydration shell is significantly larger than that of the colloidal nucleus, and thus wave breaking occurs, resulting in the elimination of surface hydration shell and the activation of colloidal nucleus, which will facilitate filling blockage of micro-defects. The simulation results are basically consistent with the theoretical analysis, which provides a theoretical support for further researches on the differential pressure activated sealant.

Key words: differential pressure activated sealant, micro-defects, adaptive repair, composite droplets, jet deformation, mechanical-chemical coupling model, numerical simulation

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