石油学报 ›› 2015, Vol. 36 ›› Issue (3): 378-384.

• 石油工程 • 上一篇    下一篇

页岩储层温敏型P(NIPAm-co-AA)/nano-SiO2复合封堵剂的制备及特性

王伟吉, 邱正松, 钟汉毅, 黄维安, 赵欣, 董兵强, 暴丹   

  1. 中国石油大学石油工程学院 山东青岛 266580
  • 收稿日期:2014-04-22 修回日期:2015-01-02 出版日期:2015-03-25 发布日期:2015-03-11
  • 通讯作者: 邱正松,男,1964年9月生,1985年获华东石油学院学士学位,2001年获石油大学(华东)博士学位,现为中国石油大学(华东)石油工程学院教授、博士生导师,主要从事油气井工作液方面的研究。Email:qiuzs63@sina.com
  • 作者简介:王伟吉,男,1987年11月生,2011年获中国石油大学(华东)学士学位,现为中国石油大学(华东)油气井工程专业博士研究生,主要从事钻井液技术研究工作。Email:wangweiji2007@126.com
  • 基金资助:

    国家重大科技专项(2011ZX05021-004)、中央高校基本科研业务费专项资金项目(15CX06021A、13CX06033A)、山东省博士后创新项目专项资金项目(201303060)和中国博士后科学基金第55批面上基金项目(2014M551986)资助

Preparation and properties of thermosensitive poly(NIPAm-co-AA)/nano-SiO2 composite blocking agent for shale gas reservoir

Wang Weiji, Qiu Zhengsong, Zhong Hanyi, Huang Wei'an, Zhao Xin, Dong Bingqiang, Bao Dan   

  1. College of Petroleum Engineering, China University of Petroleum, Shandong Qingdao 266580, China
  • Received:2014-04-22 Revised:2015-01-02 Online:2015-03-25 Published:2015-03-11

摘要:

页岩具有极低的渗透率和极小的孔喉尺寸,传统封堵剂难以在页岩表面形成有效的泥饼阻止液相侵入,只有纳米级颗粒才能封堵页岩的孔喉,阻止液相侵入地层,维持井壁稳定,保护储层。采用硅烷偶联剂KH570对纳米SiO2进行超声表面改性,引入乙烯基功能基团,80℃下使其与温敏性单体N-异丙基丙烯酰胺(NIPAm)、亲水性单体丙烯酸(AA)共聚,通过调节NIPAm、AA摩尔比制得不同最低共溶温度(LCST)值的温敏型P(NIPAm-co-AA)/nano-SiO2复合封堵剂,并用红外光谱、透射电镜和热重分析对产物进行表征。通过透光率测试研究了其温度响应行为,通过下志留统龙马溪组岩样的压力传递实验研究了其封堵性能。结果表明,P(NIPAm-co-AA)/nano-SiO2温度响应行为灵敏,存在明显的LCST值,随亲水性单体AA含量的增加,其LCST值不断升高;温度在LCST值以上,该封堵剂同时发挥物理封堵和化学抑制双重作用,阻缓压力传递效果显著,封堵后页岩表面呈疏水性,完全阻隔了水的传递。

关键词: 纳米封堵剂, 页岩气, 井壁稳定, 温敏型智能高分子, 钻井液

Abstract:

Traditional blocking agent is difficult to form effective mud cake to prevent liquid penetration due to the characteristics of shales with extremely low permeability and tiny pore throat, while nanoscale particles can block shale pore throat to prevent liquid into formation, thus maintaining wellbore stability and protecting the reservoir. The surface of nano SiO2 particles was modified by silane coupling agent KH570 under ultrasound to introduce vinyl functional group. Through the radical graft copolymerization of thermosensitive monomer N-isopropylacrylamide and hydrophilic monomer acrylic acid onto the modified surface of SiO2 nano particles at 80℃, a series of thermosensitive poly(NIPAm-co-AA)/nano-SiO2 composite blocking agents with different LCST values were prepared by adjusting the mole ratio between NIPAm and AA and were characterized by FT-IR, TEM and TG. The temperature response behavior was studied by light transmittance test while the sealing performance was studied by the pressure transmission test on the shale samples of Lower Silurian Longmaxi Formation. Laboratory investigation showed that the blocking agents with sensitive temperature response behavior had obvious LCST value which arises with the increase of hydrophilic monomer AA. If the temperature was higher than the LCST value of the products the blocking agents played a dual role of physical plugging and chemical inhibition, slowing down pressure transmission remarkably. The surface of shale sealed by the new products presented a hydrophobic property, completely cutting off the water invasion.

Key words: nano blocking agent, shale gas, wellbore stability, thermosensitive intelligent polymer, drilling fluid

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