
第33卷第4期 2016年7月
钻井液与完井液
DRILLINGFLUID &COMPLETIONFLUID
doi: 10.3696/j.issn.1001-5620.2016.04.009
Vol.33 No. 4
July2016
硅烷偶联剂改性纳米SiO,封堵剂的制备与作用机理
褚奇,杨枝,李涛,薛玉志,刘四海
(中国石化石油工程技术研究院,北京100101)
褚奇等.硅烷偶联剂改性纳米SiO,封堵剂的制备与作用机理[1].钻并液与完并液,2016,33(4):47-50
摘要以正硅酸乙酯(TEOS)为硅源,氢水为催化剂,水为促进剂,苯乙胺丙两基三甲氧基硅烷为表面改性剂,采用溶胶-凝胶法,制备了一种具有核壳结构的改性纳米SiOz。借助傅立叶红外光谱(FT-IR)、激光粒度分析仪(PSDA)和透射电镜(TEM),表征了改性纳米SiO,的分子结构,并对比了其与未改性纳米SiO,在钻井液滤液中的粒度分市和微观形貌特征。通过模拟纳微米级孔隙地层封堵率测试实验,评价了不同纳米SiO,对纳微米微裂隙的封堵能力,并探讨了其在钻并液中纳米级分散作用机理。实验结果表明,改性纳米SiO,在钻并液中呈现纳米级分散,相比于未改性SiO,而言,可有效对纳微米裂隙进行封堵;当质量百分浓度为3.0%时,对模拟纳微米级地层的封堵率达到99.21%。
关键词钻井液;纳米二氧化硅;硅烷偶联剂;粒度分布;微观形貌
中图分类号:TE254
文献标识码:A
文章编号:1001-5620(2016)04-0047-04
Preparation and Analyses of Nano SiO, Plugging Agent Modified with Silane Coupling Agent
CHU Qi, YANG Zhi, LI Tao, XUE Yuzhi, LIU Sihai
(Sinopec Research Institute of Petroleum Engineering, Bejing 100101)
Abstract A modified nano SiO, with core-shell structure was prepared through sol-gel method, using tetraethoxysilane (TEOS) as the source of Si, ammonia water as catalyst, water as accelerant, and phenylethylamine propyl trimethoxy silane as surface modifier. The molecular structure of the SiO, was characterized through FT-IR, PSDA and TEM, and the modified SiO, was compared with non modified SiO, as to the particle size distribution and microscopic morphology in the filtrate of drilling fluid. Several nano SiO, additives were evaluated by testing their capabilities to plug nano fractures on a simulator, and the mechanism of nano-dispersion of these SiO additives in drilling fluids was discussed. Compared to non-modified SiO, the modified SiO, shows nano-dispersion in drilling fluids and can effectively plug the nano-sized fractures. At a concentration of 3.0%, 99.21% of the nano-sized fractures on the simulator were plugged.
Key words Drilling fluid; Nano SiO,; Silane coupling agent; Particle size distribution; Microscopic morphology
传统的化学抑制防塌方法只适用于易膨胀的泥页岩地层,而不适用于含裂隙硬脆性泥页岩地层1-2)。对于含裂隙硬脆性泥页岩来说,井壁稳定的关键是阻止孔隙压力传递,而阻止孔隙压力传递则必须加强对微裂隙的封堵(3-5)。目前使用的钻井液封堵材料的粒径峰值在0.5~10.0μm,难以对孔隙尺寸为0.001~0.01μm的纳微米孔隙实施有效封堵,使得钻井液滤液易沿着这些孔隙进人地层内部,造成岩石裂隙发展,整体强度下降,导致井壁
失稳情况的发生。市面上的纳米封堵材料虽然在粒径上达到了纳米级,但由于纳米材料具有比表面能大和易团聚的特点,使其在液相中并不能以纳米级水平分散,难以对纳微米的孔隙进行封堵[7-9]。通过实验,采用溶胶-凝胶法制备纳米SiO2,并利用硅烷偶联剂苯乙胺丙基三甲氧基硅烷对反应生成的纳米SiO,颗粒进行改性,将其表面由亲水性转变为疏水性,以提高空间稳定性,得到可在钻井液中以纳米级水平均匀分散的改性纳米SiO2。
基金项目:中国石油化工股份有限公司科技攻关项目“微裂地层纳微米封堵井筒强化技术”(P14100)
第一作者简介:褚奇,副研究员,博士,1982年生,2012年毕业于西南石油大学应用化学专业,现在从事油田化学
品的研究与现场应用工作。电话(010)84988610/18611781706;E-mail:chuqi.sripe@sinopec.com。万方数据