石油磺酸盐表面活性剂弱碱体系三元复合驱采出水的显微结构和油水分离特性  

Microscopic structures and oil/water separation behaviors of produced water by ASP flooding using Na_2CO_3,petroleum sulfonate and partially hydrolyzed polyacrylamide

作　　者：吴迪[1,2] 王翀[1] 赵凤玲[1] 张会平[1] 孟祥春[1] 孙景欣[1] 赵觅[3] 

机构地区：[1]大庆油田工程有限公司,黑龙江大庆163712 [2]大庆油田工程建设有限公司,黑龙江大庆163712 [3]东北石油大学化学化工学院,黑龙江大庆163318

出　　处：《精细与专用化学品》2015年第8期27-33,共7页Fine and Specialty Chemicals

摘　　要：大庆油田北二西试验区石油磺酸盐表面活性剂弱碱体系三元复合驱现场试验中暴露出采出水沉降和过滤除油效果差,过滤后回注采出水含油量严重超标的问题。为确定该试验区三元复合驱采出水中O/W型原油乳状液的主要稳定机制,采用显微观测、光散射、重力沉降、离心沉降和膜过滤等试验手段对该试验区综合采出水和4口典型油井采出水进行了结构和油水分离特性测试,确定该试验区综合三元复合驱采出水中含有约40mg/L粒径为0.08～1μm的亚微米油滴,这些油滴粒径小,聚并和浮升能力差,难以通过沉降和过滤工艺有效去除,是造成该试验区三元复合驱采出水除油困难的主要原因;北二西试验区三元复合驱采出水中亚微米尺度油滴的主要来源为注入液与油藏中原油接触形成的增溶有原油的膨胀胶束,在采油、集油和采出液处理过程中当混合流体水相中表面活性剂浓度降低到临界胶束浓度（cmc）以下时,膨胀胶束发生崩溃,释放出其中增溶的原油,形成粒径细小的油滴。During an ASP flooding project conducted at the N2W block of daqing field, in which Na2 CO3, petro- leum sulfonate surfactant and partially hydrolyzed polyacrylamide were injected, poor oil removal performances of both skim tanks and bed filters were exposed, resulting in excessive oil carryover in re-injection water. In an effort to identify the major mechanisms governing the stability of the tight o/w crude oil emulsion in the troublesome produced water, structures and oil/water separation behaviors of the influent water at produced water treatment facility, as well as waters produced by 4 typical producers, were studied by microscopy, light scattering, gravity settling, centrifugal settling, depth filtration and membrane filtration. Submicron oil droplets with diameters ran- ging from 0. 089m to μm, for which creaming and coalescence were both difficult, were identified in the influent water of produced water treatment facility at a total content of about 40mg/L and to largely account for the poor oil removal performances of gravity settling and depth filtration. Oil binding swollen micelles formed by contact of injected fluid with oil in the reservoir, which collapsed and released tiny oil droplets during oil production and pro- duced fluid surface handling when surfactant concentration in the water phase of the diluted fluid was below critical micells concentration （cmc）, were identified to be the main sources of the submicron oil droplets in the blended pro duced water entering water treatment facility.

关 键 词：三元复合驱 采出水 除油 结构 碳酸钠 石油磺酸盐表面活性剂 

分 类 号：TE357.46[石油与天然气工程—油气田开发工程]