油藏岩石润湿性对注水过程中驱油效率的影响

在前人工作的基础上，采用更为合理的实验条件，进一步确认油藏岩石的润湿性与油井注水过程中驱油效率的关系。从而为今后改进注水作业措施，提高注水采收率提供实验依据。在尽可能消除其它影响因素的情况下，使用Ａｍｏｔ法，定量地评价了贝雷砂岩的润湿性对注水过程中驱油效率的影响。研究结果表明，贝雷砂岩原有的强亲水性随原油沥青质吸附量的增加而逐渐减弱；对于经原油沥青质吸附的弱水湿岩样，其最终驱油效率均明显高于强水湿岩样。当Ａｍｏｔ润湿指数（Ｉｗｏ）在０．２左右时，可获得最高的最终驱油效率。

/ EFFECT OF ROCK WETTABILITY ON OIL RECOVERY BY WATERFLOODING

The objective of this fundamental work is to determine the relationship between wettability of reservoir rocks and oil recovery by waterflooding on the basis of previous research work. The more rational test conditions are applied to provide the basis for improving the waterflooding operations and enhancing oil recovery by waterflooding. The effect of wettability of berea sandstone on waterflood recovery has been quantitatively evaluated by using the Amott method when other influencing factors are eliminated as far as possible. The experimental results indicate that the water wet behavior of berea sandstone decreases with the increase in the amount of crude asphaltene adsorbed onto sandstone, and the final waterflood recoveries for the weakly water wet core samples adsorbed with crude oil asphaltene are considerably higher than those of strongly water wet core sample. The highest oil recoveries by waterflooding can be obtained when the Amott wettability index ( I w o ) is approximately equal to 0.2.