功能化阳离子絮凝剂处理油田三元复合驱采出水的效能及机制  

Efficiency and Mechanism of the Treatment by Functionalized Cationic Flocculants for Alkali-Surfactant-Polymer Flooding-Produced Water in Oilfield

作　　者：于忠臣[1] 张子良 王松[2] 赵宇 白健华 齐晗兵[1] 孙超 YU Zhongchen;ZHANG Ziliang;WANG Song;ZHAO Yu;BAI Jianhua;QI Hanbing;SUN Chao(School of Civil Engineering and Architecture,Northeast Petroleum University,Daqing 163318,China;School of Earth Science,Northeast Petroleum University,Daqing 163318,China;Tianjin Branch of China National O f fshore Oil Corporation,Tianjin 300452,China)

机构地区：[1]东北石油大学土木建筑工程学院,黑龙江大庆163318 [2]东北石油大学地球科学学院,黑龙江大庆163318 [3]中海石油(中国)有限公司天津分公司,天津300452

出　　处：《石油学报（石油加工）》2023年第3期552-561,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：国家自然科学基金项目(5207040321);中国石油科技创新基金项目(2016D-5007-0604);黑龙江省科技厅应用技术研究开发项目(GC13C305);东北石油大学研究生教育创新工程项目(JYCX_CX05-2018,JYCX_JG05-2018)资助。

摘　　要：油田三元复合驱采出水中由于含有聚合物、碱和表面活性剂等物质,使油珠界面膜强度增强、油滴聚并空间位阻增大,体系呈现高稳定状态,因此,开发出一种适合三元复合驱采出水体系的新型絮凝剂,使体系脱稳、油珠聚并,成为油田生产中亟待解决的问题之一。以聚丙烯酰胺(PAM)为主链骨架,丙烯酸丁酯(BA)和二甲基二烯丙基氯化铵(DMDAAC)为单体,利用水溶液自由基胶束聚合法制备P(AM-DMDAAC-BA)功能化阳离子絮凝剂。采用傅里叶红外光谱(FT-IR)和核磁共振氢谱(^(1)H NMR)表征其基团和分子结构;利用分形维数和絮体粒径来确定絮凝剂最佳投量;利用絮凝实验考察絮凝剂对三元复合驱采出水的处理效能;利用反演法探究絮凝机制。结果表明:P(AM-DMDAAC-BA)功能化阳离子絮凝剂具有超疏水功能,其疏水基团分子结构是BA分子中C=C双键与AM母体的亚甲基通过C—C键相连;絮凝剂最佳投加量为40.0 mg/L,沉降时间为8.0~10.0 h,絮体粒径可达677.0μm以上,絮体分形维数为1.502,絮体结构紧密,沉降性能良好,油和悬浮物的平均去除率在86.4%以上,比油田在用絮凝剂平均去除率提高了26.6百分点。功能化阳离子絮凝剂通过BA疏水基团强化网捕和卷扫作用,对水中悬浮颗粒具有界面间架桥效应。同时,DMDAAC阳离子基团使油珠和悬浮颗粒表面电荷产生电性中和作用,使油珠与油珠、悬浮颗粒与悬浮颗粒聚并,形成较大的絮凝体,实现油珠、悬浮颗粒与水的高效分离。Alkali-surfactant-polymer(ASP)flooding-produced water contains polymer,alkali and surfactant,which can enhance the strength of the oil droplet interface film,increase the oil droplet coalescence space and steric hindrance,leading to a high-stability state of the system.Therefore,a new flocculant suitable for ASP flooding-produced water system needs to be developed to achieve system destabilization and oil droplet coalescence,which has become one of the urgent problems to be solved in oilfield production.P(AM-DMDAAC-BA)functionalized cationic flocculant was prepared by free radical micelle polymerization of aqueous solution when using polyacrylamide(PAM)as the main chain backbone and butyl acrylate(BA)and dimethyldiallyl ammonium chloride(DMDAAC)as monomers.Fourier transform infrared spectroscopy(FT-IR)and nuclear magnetic resonance hydrogen spectrum(^(1)H NMR)were used to characterize the groups and molecular structure;the optimal dosage of the flocculant was determined by fractal dimension and floc size;the flocculant treatment efficiency of ASP flooding-produced water was investigated by flocculation experiment;the flocculation mechanism was investigated by inversion method.The results show that P(AM-DMDAAC-BA)functionalized cationic flocculant has superhydrophobic function,and the molecular structure of its hydrophobic groups is that the C=C double bond in BA molecule is connected with the methylene group of AM parent by C—C bond.The optimal flocculant dosage is 40.0 mg/L,settling time is 8.0—10.0 h,floc size can reach above 677.0μm,fractal dimension of flocs is 1.502,floc structure is compact,settling performance is good,and the average removal rate of oils and suspended solids is above 86.4%,which increased by 26.6%compared with the flocculant used in oilfield.The functionalized cationic flocculant can strengthen the trapping and sweeping effect through BA hydrophobic groups,and can bridge the interface of suspended solids in water.At the same time,DMDAAC cationic group makes the oil droplets and suspen

关 键 词：絮凝 阳离子絮凝剂 疏水作用 采出水 

分 类 号：TQ317[化学工程—高聚物工业]