低成本O/W型乳液与岩心孔吼配伍性及其驱油效率

Oil Displacement Efficiency and Pore Size Matching of an Economic O/W Emulsion Flooding

本文利用廉价碱和少量高酸值稠油,建立了一种低成本O/W型乳液驱方法,并系统研究了乳液的物理性质以及在多孔介质中的流动行为和驱油效率。研究结果表明,在油水比0.5∶9.5条件下,通过调整转速(1500~2600 r/min)和搅拌时间(0.5数2 h)制备的一种不稳定型和三种稳定型的O/W型乳液,在岩心中流动时,由于贾敏效应,稳定型乳液的注入压力明显升高,而不稳定型乳液发生油水分离,注入压力变化不明显。从乳液驱效果上看,转速2000 r/min、搅拌时间1.5 h下形成的稳定乳液可以有效提高原油采收率达17%。乳液液滴和岩石孔喉的匹配系数f小于1时,乳液的驱油效率不高;f大于1时,乳液液滴能对岩心孔喉有效封堵,提高采收率明显。但是并非f越大提高采收率越高。

An economic chemical method was proposed based on the reaction between alkali and high acid crude oil, and the physical properties of the formed emulsion, flow behaviors and oil displacement efficiency were comprehensively investigated. It was shown that under the condition of oil to water ratio of 0.5 ： 9.5, an unstable and three stable O/W emulsions were prepared by adjusting the rotating speed （ 1500---2600 r/min） and stirring time （0.5--2 h）. Due to the Jiamin effect, the injection pressure of the stable emulsion significantly increased when flowing in the core, while the unstable emulsion occurred oil-water separation, and the injection pressure did not change significantly. The stable emulsion formed at a rotational speed of 2000 r/min and a stirring time of 1.5 h could effectively increase oil recovery by up to 17%. When the matching factorfbetween the emulsion droplets and the rock pore throats was less than 1, the oil displacement efficiency of the emulsion was not high; whenfwas greater than 1, the emulsion droplets can effectively block the pore throat and increase the recovery efficiency. However, the higherfwas not always better.