Experimental Study of Enhancing Oil Recovery with Weak Base Alkaline/Surfactant/Polymer
Experimental Study of Enhancing Oil Recovery with Weak Base Alkaline/Surfactant/Polymer
复制标题
弱碱/表面活性剂/聚合物提高采收率的实验研究
DOI：
10.1155/2017/4652181
复制
发表时间：
2017-01-01
影响因子：
3.3
通讯作者：
Gai, Jian
中科院分区：
文献类型：
--
作者：
Yin, Dandan;Zhao, Dongfeng;Gai, Jian
将Na 2CO 3与表面活性剂、聚合物复配，形成三元复合驱体系。研究了大港原油与化学品溶液的界面张力和乳化作用.实验结果表明，三元复合体系能与原油及乳化相形成超低界面张力。乳液的稳定性通过Na 2CO 3、表面活性剂和在油/水接触时产生的皂来增强。为了研究Na 2CO 3浓度对原油采收率的影响，进行了6次岩心驱油实验。结果表明，当表面活性剂用量为0.3wt%、Na 2CO 3用量为0.6wt%、聚合物用量为2000 mg/L时，采收率最高。在非均质油藏中，三元复合驱只有在达到临界粘度后才能通过降低界面张力来提高采收率，说明扩大波及体积是降低界面张力提高采收率的前提。降低或去除三元复合体系中的碱以达到高粘度会降低原油采收率，因为驱油效率会降低。弱碱性ASP碱可以保证整个体系具有足够的粘度，即使IFT仅达到10−2 mN/m，也能启动中低渗透层，提高采收率。
Na2CO3 was used together with surfactant and polymer to form the Alkaline/Surfactant/Polymer (ASP) flooding system. Interfacial tension (IFT) and emulsification of Dagang oil and chemical solutions were studied in the paper. The experiment results show that the ASP system can form super-low interfacial tension with crude oil and emulsified phase. The stability of the emulsion is enhanced by the Na2CO3, surfactant, and the soap generated at oil/water contact. Six core flooding experiments are conducted in order to investigate the influence of Na2CO3 concentration on oil recovery. The results show the maximum oil recovery can be obtained with 0.3 wt% surfactant, 0.6 wt% Na2CO3, and 2000 mg/L polymer. In a heterogeneous reservoir, the ASP flooding could not enhance the oil recovery by reducing IFT until it reaches the critical viscosity, which indicates expanding the sweep volume is the premise for reducing IFT to enhance oil recovery. Reducing or removing the alkali from ASP system to achieve high viscosity will reduce oil recovery because of the declination of oil displacement efficiency. Weak base ASP alkali can ensure that the whole system with sufficient viscosity can start the medium and low permeability layers and enhance oil recovery even if the IFT only reaches 10−2 mN/m.