油气藏评价与开发 ›› 2018, Vol. 8 ›› Issue (6): 57-61.

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成膜封堵技术室内实验研究

吴若宁,熊汉桥,苏晓明,朱杰,孙运昌,王启任   

  1. 西南石油大学油气藏地质及开发工程国家重点实验室,四川 成都 610500
  • 收稿日期:2017-11-23 出版日期:2018-12-26 发布日期:2018-12-13
  • 作者简介:吴若宁(1993—),男,在读硕士研究生,油气层保护技术研究。

Research on indoor experiment of film formation and plugging technology

Wu Ruoning,Xiong Hanqiao,Su Xiaoming,Zhu Jie,Sun Yunchang,Wang Qiren   

  1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China
  • Received:2017-11-23 Online:2018-12-26 Published:2018-12-13

摘要:

钻井过程中,当钻遇复杂段地层时,由于钻井液的渗漏,容易引发井壁失稳。针对这种情况提出了钻井液成膜封堵思路,室内采用扫描电镜分析了成膜钻井液泥饼的微观结构,通过透水实验评价了封堵膜的抗水化性能,利用改进的砂床实验模拟了成膜钻井液对不同渗透性地层的封堵情况,使用自主设计的未固结砂岩心流动实验对形成封堵膜的正向承压能力和返排效果进行了研究。实验结果表明:成膜钻井液抗温能力可达150 ℃,API滤失形成的泥饼更加致密;相同时间段内,泥饼透水量基本保持不变,封堵膜具有一定的抗水化性能;当成膜封堵剂加量为2 % ~ 3 %时,不同目数的砂床被完全封堵,钻井液无滤失,封堵膜形成后正向承压值较高,可以达到16 MPa,反向驱动时,突破压力为0.5 ~ 1 MPa,返排效果好。

关键词: 渗漏, 成膜封堵, 封堵膜, 抗水化, 滤失

Abstract:

During the drilling process in complex sections of the formation, due to the leakage of the drilling fluid, the borehole instability occurs easily. In view of this situation, we put forward the film formation and plugging project of the drilling fluid. In the indoor experiment, the microstructure of the mud cake was analyzed by scanning electron microscopy(SEM). The hydration resistance of the plugging film was evaluated by the water permeation tests. The improved sand bed experiment had simulated the plugging performance of the drilling fluid on the formations with different permeability. Then, we analysed the positive pressure capacity and flowback effect of the plugging film by the self-designed unconsolidated sand core flow experiments. The experimental results showed that the film-formation drilling fluid was resistant to the highest temperature of 150 ℃, and the mud cake formed by API leak-off was denser. In the same period, the water permeability of the mud cake remained unchanged and the plugging film had certain hydration resistance. When the dosage was between 2 % ~ 3 %, the sand beds with different mesh were totally blocked, without the leak-off of the drilling fluid, and the positive pressure value was high after the plugging film formed, which could reach 16 MPa. In the reverse driving, the breakthrough pressure was between 0.5 ~ 1 MPa with good flowback effect.

Key words: leakage, film formation and plugging, plugging film, hydration resistance, leak-off

中图分类号: 

  • TE254