驱油剂产出高峰期三元复合驱采出液的油水分离特性和影响因素分析

Phase separation performances of field alkaline/surfactant/polymer flooding produced fluid during peak production of injected chemicals and major influencing factors

对大庆油田2座接收和处理石油磺酸盐表面活性剂弱碱体系三元复合驱采出液的转油站和转油放水站的采出液集输和处理工艺参数、外输液的成分和相分离特性等进行了长期跟踪监测。驱油剂产出高峰期,2座站三元复合驱外输液游离水表面活性剂含量最大值为299mg/L,pH值最高为9.5,聚合物含量最大值为1147mg/L;新中302转油站和北Ⅲ-6转油放水站三元复合驱外输液综合含水率分别为94.1%~98.3%和43.2%~93.5%,外输液5min静置沉降水相乳化油量平均值分别为4621mg/L和1946mg/L;外输液中的油包水型低含水率乳化油在60℃的环境下经过24h静置沉降后的残余水含量平均值分别为2.63%和0.15%。采用相关性分析方法对转油站和转油放水站外输液相分离特性与成分和油水分离剂加药浓度等参数之间的相关性进行了分析,指出了驱油剂产出高峰期转油站和转油放水站外输三元复合驱采出液油水分离特性的主要影响因素。

Operation parameters,composition and phase separation performances of oil exports of two production stations handling produced fluid by alkaline/surfactant/polymer(ASP)flooding injecting Na_(2)CO_(3),petroleum sulfonate and partially hydrolysed polyacrylamide at Daqing Fields were routinely monitored and evaluated.During peak production of injected chemicals,the maximum values of surfactant content,pH and polymer content of free water in the oil export of the two production stations were respectively 299mg/L,9.5and 1147mg/L.The overall water-cuts of the oil export of NM-302production station and N3-6production station were respectively 94.1%~98.3%and 43.2%~93.5%;the average emulsified oil contents in the water phase of the oil exports after 5min static settling were respectively 4621mg/L and 1946mg/L;the average residual water-cuts of the water in oil crude oil emulsions extracted from the oil exports after 24h static settling at 60℃were respectively 2.63%and 0.15%.Phase separation performances of the oil exports were correlated with its composition,chemical treatment and process parameters of produced fluid handling.Major factors governing the phase separation performances of field ASP flooding produced fluid exported by production stations during peak chemical production were identified.