接枝低分子量配体改性纳米粒子强化乳液研究  

Study on Nanoparticles Grafted with Low Molecular Weight Ligands for Enhanced Emulsion

作　　者：贺东旭[1] HE Dongxu(Zhuangxi Oil Produdon Plant,SINOPEC Shengli Oilfield Branch,Dongying,Shandong 257237,China)

机构地区：[1]中国石化胜利油田分公司桩西采油厂

出　　处：《钻采工艺》2022年第5期128-133,共6页Drilling & Production Technology

基　　金：中石化科技推广项目“纳米材料强化乳液增产技术推广与应用”(编号:P21099)。

摘　　要：乳状液由于其优异的界面性质,可以通过贾敏效应控制其在多孔介质中的流动阻力,而基于纳米二氧化硅稳定的乳状液可以获得比单纯表面活性剂稳定的乳状液更加优异的稳定性和界面弹性,但是油田使用的配液水中存在较高的盐含量,由于电荷屏蔽等作用纳米二氧化硅在高矿化度盐水中的稳定性较差,从而导致其在油田的应用受到极大的限制。因此为了提高纳米二氧化硅在盐水中的稳定性,制备可用于油田现场调驱的纳米二氧化硅稳定的乳状液,因此研究中利用低分子量配体[3-(2,3-二羟基丙氧基)丙基]-三甲氧基硅烷对纳米材料二氧化硅表面进行改性,并通过红外光谱、固体核磁以及TEM对改性后的纳米二氧化硅进行了结构表征。动态光散射实验表明改性的二氧化硅纳米粒子的流体动力学直径在室温和高达70℃的温度下超过30 d基本保持恒定,说明该改性方法大幅度提高了纳米材料在含有二价阳离子的浓盐水中的空间稳定性,利用该纳米材料制备了水包油乳状液体系,并进行了矿场应用,措施井组综合含水率由调驱前的96.2%降至91.9%,降低4.3%;井组日产油量由4.6 t增加至8.3 t,日增油量达3.7 t,取得了较好的降水增油效果。该研究对于提高纳米材料在油田中的应用奠定了基础。Emulsions can control their flow resistance in porous media through the Jamin effect due to their excellent interfacial properties.Emulsions stabilized on the basis of nano-silica can achieve superior stability and interfacial flexibility than emulsions stabilized by pure surfactant.However,there is a high salt content in the dispensing water used in the oilfield.Since the poor stability of nano-SiO_(2) in high salinity brine due to the effect of charge shielding,its application in oil fields is greatly limited.Therefore,in order to improve the stability of nano-SiO_(2) in brine,nano-SiO_(2) stabilized emulsions that can be used on-site control and flooding in oilfields were prepared.In the study,the low molecular weight ligand[3-(2,3-dihydroxypropoxy)propyl]-trimethoxysilane was used to modify the surface of nanomaterials.And the structure of the modified nano-SiO_(2) was characterized by IR,solid-state ^(13)C NMR and TEM.Dynamic light scattering experiments show that the particle size distribution of the modified silica nanoparticles remains constant at room temperature and up to 70℃for more than 30 days,which indicates that the modified method greatly improves the spatial stability of nanomaterials in concentrated brine containing divalent cations.The oil-in-water emulsion system was prepared using this nanomaterial and applied in the mine site.The comprehensive water content of the measured well group was reduced from 96.2%before the profile control and displacement and drive to 91.9%,a reduction of 4.3%;the daily oil production of the well group increased from 4.6 t to 8.3 t,with a daily oil increase of 3.7 t,achieving a better effect of water reduction and oil increase.This study lays a foundation for improving the application of nanomaterials in oil fields.

关 键 词：纳米二氧化硅 接枝改性 耐盐性 乳状液 提高采收率 

分 类 号：TE357[石油与天然气工程—油气田开发工程] TB383.1[一般工业技术—材料科学与工程]