高温高盐底水油藏强化泡沫体系试验研究

我国底水油藏储量丰富,底水油藏的开发面临底水脊进的问题.泡沫具有视黏度高和选择性封堵能力,能够在底水油藏开发过程中起到压脊作用.为了得到压脊效果较好的强化泡沫,首先通过室内试验评价泡沫综合指数,筛选出了较好的起泡剂SA、DR和AM;然后进行了起泡剂的复配试验,筛选出4种泡沫综合指数较高的普通泡沫体系;为增强普通泡沫体系在高温高盐条件下的稳定性,加入聚合物稳泡剂,得到了强化泡沫体系.在模拟实际油藏条件下,对强化泡沫体系进行了7,14,21和28 d的老化试验,筛选出热盐稳定性较好、可用于现场的0.15%AM+0.05%DR+0.20%WP4强化泡沫体系.平板试验结果表明,强化泡沫体系的压脊效果比普通泡沫体系好,采收率提高明显. 

An Experimental Study of Enhanced Foam Systems Used in High Temperature and High Salinity Bottom Water Reservoirs

Oil reservoirs that contain bottom water are abundant in China. However, the development of such reservoir is challenged by bottom water coning and ways of controlling it. Foam has the property of high apparent viscosity and high selective plugging ability, and it can have obvious pressure ridge effect in the development of bottom water reservoir. For the foams more effective, the better foaming agents SA, DR, AM were screened out through lab tests and by evaluating the foam composite index. Meanwhile, tests for compound of the foaming agents were conducted and four kinds of common foam system of high foam composite index were selected. In order to enhance the stability of common foam systems under the conditions of high temperature and high salinity, a polymer stabilizing foam agent was added and an enhanced foam system was formed. Under the simulated conditions of actual reservoir, aging tests were conducted for enhanced foam systems, for 7 days, 14 days, 21 days and 28 days. Finally, the enhanced foam system of 0.15%AM+0.05%DR+0.2%WP4 was selected for its better stability under high temperature and high salinity and applicability on rig site. The result of the flat model test showed that the pressure ridge effect of the enhanced foam system was better than the common foam system in high temperature and high salinity bottom water reservoirs, and improving the recovery rate apparently.