压力对改性α-烯烃磺酸盐起泡剂泡沫性能的影响

EFFECT OF PRESSURE ON FOAMING PROPERTIES OF MODIFIEDα-OLEFIN SULFONATE FOAMING AGENT

为满足高含水老油田调驱的需要,研制了一种改性α-烯烃磺酸盐起泡剂。通过与两种现场用起泡剂发泡性能和泡沫稳定性的对比,初步选定改性α-烯烃磺酸盐起泡剂作为调驱用起泡剂。通过一维可视化泡沫微观物理模拟装置视窗观察可以看出,在恒定压力、不同气液比以及恒定气液比、不同压力条件下,泡沫外形清晰、性能稳定,说明改性α-烯烃磺酸盐起泡剂在高压下具有较好的发泡性能和泡沫稳定性能。高压下泡沫性能研究表明,随着压力的升高,改性α-烯烃磺酸盐起泡剂的起始发泡体积略有降低,而起泡剂的泡沫半衰期显著提高,即泡沫体系的稳定性逐渐增强。利用不同渗透率的岩心对改性α-烯烃磺酸盐起泡剂的泡沫封堵性能进行了考察。结果表明,在高渗条件下的最高阻力系数优于低渗条件下最高阻力系数;在最高阻力系数时,低渗气液比要高于高渗气液比。

In order to meet the needs of profile control and oil displacement process in old oilfields with high water cut,a modifiedα-olefin sulfonate foaming agent was developed.By comparing the foaming property and foam stability of two foaming agents presently used in the field,it was preliminarily determined to adopt the modifiedα-olefin sulfonate foaming agent as foaming agent for profile control and oil displacement.Through the observation of one-dimensional visual foam microphysical simulation device,it could be seen that the foam shape was clear and the foam stability was good under constant pressure with different gas-liquid ratios and at constant gas-liquid ratios with different pressures,indicating that the modifiedα-olefin sulfonate foaming agent had excellent foaming properties and foam stability under high pressure.The study of foam performance under high pressure showed that the initial foaming volume of the modifiedα-olefin sulfonate foaming agent system slightly decreased with the increase of pressure,while the foam half-life of the foaming agent system increased significantly,that is,the stability of the foam system gradually increased.The foam plugging performance of the modifiedα-olefin sulfonate foaming agent was also investigated by using cores with different permeability.The result showed that the highest resistance coefficient under high permeability condition was better than that under low permeability condition.At the highest resistance factor,the gas-liquid ratio of low permeability was higher than that of the high permeability.The above research results have important guiding significance for the study of the action mechanism and the field application of foaming agent.