基于临界胶束浓度的三元复合驱采出水稳定性研究

Study on the Stability of ASP Flooding Produced Water based on Critical Micelle Concentration

通过对大庆油田二厂南四-8(弱碱)和四厂三元-6(强碱)三元复合驱采出水水质特性进行测定,结合采出水粒径分布和形貌特征,利用临界胶束浓度(CMC)理论探索采出水的稳定性,并分析了驱油剂、温度、p H和无机盐对采出水CMC的影响.采出水CMC远小于原水浓度,表明三元水体系中形成双分子层;采出水CMC受体系p H影响相对较大,即驱油剂中的碱可与原油中的活性物发生皂化反应生成有机酸盐,具有一定的亲水亲油活性;聚合物在增大采出水黏度同时具有表面活性剂的性质,在碱的作用下部分水解,形成聚电解质,促进双电子层的形成.

The water quality characteristics of the produced water from Nan 4-8(weak alkali)and Sanyuan-6(strong alkali)of Daqing Oilfield were measured.Combining the particle size distribution and morphological characteristics of the produced water,the critical micelle concentration(CMC)theory was used to discuss the stability of the oil displacement water,and the influences of oil displacement agent,temperature,pH value and inorganic salt on the CMC of the produced water were analyzed.The ASP flooding water CMC is much smaller than the flooding water raw water concentration,indicating that a bilayer is formed in ASP water system.The CMC of flooding water is relatively affected by the pH of the system,that is,the alkali in the oil displacing agent can react with the active substances in the crude oil to form organic acid salts,which have a certain hydrophilic and lipophilic activity.The polymer has the properties of a surfactant while increasing the viscosity of the flooding,and is partially hydrolyzed under the action of an alkali to form a polyelectrolyte and promote the formation of a double-electron layer.