渤海油田不同时机聚合物驱油效果研究

Effect of polymer flooding occasion on development result of Bohai Oilfield

为研究海上油田不同时机聚合物驱油效果,使用渤海油田的油藏数据,采用物理模拟实验和数值模拟相结合的方法分析了不同时机聚合物驱在波及面积、无水采油期和驱替前缘形态等方面的特征。为兼顾不同时机聚合物驱增油及降水效果,定义综合换油率来表征不同时机聚合物驱油效果。结果表明,与中后期聚合物驱比较,早期聚合物驱前缘推进均匀,注入水突破时间延迟,波及效率高,油藏驱替效果得到改善。注聚合物时机较早,开发早期综合换油率较高,早期聚合物驱能在有限的时间内将增油和降水的作用发挥得更好。对于受开发时间限制及要求高速高效开发的海上油田,早期聚合物驱技术优势明显。

To identify the displacement effect of polymer flooding at different times in offshore oilfields,the differences in the sweep area,the water-free oil production period and the displacement front morphology of the polymer flooding at different times are studied using the oil reservoir data of Bohai Oilfield by means of physical simulation experiments and numerical simulation. The displacement effect of polymer flooding is characterized by a parameter of integrated oil displacement efficiency,which can comprehensively characterize the oil increasing and water decreasing effect of polymer flooding. The results show that,compared with the polymer flooding in the medium and late period of reservoir development,the polymer flooding in the early period of reservoir development has more uniform displacement front,later water breakthrough and higher sweep efficiency,and a better oil displacement effect can be achieved. The earlier the time of polymer flooding,the higher early integrated oil displacement efficiency. Early polymer flooding can better play the role of oil increasing and water decreasing of polymer flooding in the limited time,so it has obvious advantages for the offshore oilfields which are limited by development time and require high development efficiency.