大庆油田三元复合驱采出液热化学破乳研究  

Thermo-Chemical Demulsification/Dehydration of High Water Cut Crude Oil Produced from ASP Flooding Reservoir in Daqing

作　　者：吴迪[1] 王世昌[1] 孟祥春[2] 孙福祥[2] 赵凤玲[2] 王庆生[2] 梁辉诚[2] 

机构地区：[1]天津大学化工学院化学工程研究所,天津300072 [2]中国石油大庆油田公司油田建设设计研究院水化室,黑龙江大庆163712

出　　处：《油田化学》2002年第1期54-58,共5页Oilfield Chemistry

摘　　要：以模拟三元复合驱采出液为介质研制了大庆油田表面活性剂ORS 4 1三元复合驱O/W型采出液热化学脱水的破乳剂 ,用模拟采出液和实际采出液评价了其破乳性能并通过测试模拟含油污水的油珠聚并、水相粘度、油水界面张力、油珠Zeta电位和油水界面流变性的方法研究了大庆油田表面活性剂ORS 4 1三元复合驱O/W型采出液的热 化学破乳机理。实验结果表明 ,表面活性剂ORS 4 1三元复合驱O/W型采出液在破乳剂加药量为 15 0mg/L、脱水温度为 45℃和沉降时间为 3h的条件下 ,可经热 化学脱水达到外输原油含水率指标 ;三元复合驱O/W型采出液的热 化学破乳机理为 :破乳剂ASPD 1吸附到油水界面上顶替原油中的天然界面活性物质、碱与原油中天然物质反应生成的界面活性物质和驱油表面活性剂 ,降低油珠表面的负电性和油珠之间的电排斥力 ,促进油珠之间的聚并 ,使油珠上浮速率加大并使O/W型三元复合驱采出液分层后所形成的油珠浓缩层内的油珠粒径增大 ,使得油珠聚并过程中被束缚在油相中的水滴直径增大 ,使所形成的W /O型乳化原油的稳定性下降 ,容易破乳。A demulsifier, ASPD-1, was developed for thermo-chemical dehydation of the high water cut crude oil (O/W emulsions) produced from an ASP flooding reservoir in Daqing (the surfactant in ASP flooding solution-Witcos ORS-41 and alkaline NaOH). The performance properties of the demulsifier were evaluated both in artificial 30/70 O/W emulsions and in produced fluid taken from a gathering plant. It was ascertained that the high water cut crude oil in form of O/W emulsion produced from the ASP flooding reservoir in Daqing can be demulsified and dehydrated by ASPD-1 of dosage 150 mg/kg at 45℃ in 3 hrs of standing to obtain crude oil of water content below 0.5%. The mechanisms involved in demulsification/dehydration were investigated through experiments on oil droplet coalescence and measurements of water phase viscosity, dynamic and equilibrium oil/water interfacial tensions, oil/water interfacial rheologic characteristics, and oil droplet zeta potential and considered to include adsorption of demulsifier molecules onto and replacement of indigenous and injected surfactants from oil/water interfaces, reduction of the negative charge density on oil droplet surfaces and the repulsing forces between approaching oil droplets and these lead to oil droplet coalescence, O/W emulsion breakdown, destabilization of W/O emulsion thus formed and crude oil dehydration.

关 键 词：高含水原油 O/W型乳状液 破乳剂 破乳脱水 机理 三元复合驱油藏 大庆油田 

分 类 号：TE868[石油与天然气工程—油气储运工程] TE357.46