注聚后期注入封堵段塞效果分析

Effect analysis of injecting plugging slug at later stage of polymer injection

为提高注聚合物后期聚合物驱区块开发效果,开展了注聚后期注入封堵段塞效果分析。停注聚合物前注入高质量浓度封堵段塞,能够充分利用高质量浓度聚合物的黏弹性进一步提高聚合物驱效果。W聚合物驱工业区两个井区开展注聚合物后期分别注入中相对分子质量高质量浓度和高相对分子质量高质量浓度封堵段塞的试验:中相对分子质量高质量浓度封堵段塞注入后,试验井区注入井差层有效厚度吸液比例提高了6. 9%,试验井区采出井含水率下降幅度在1%以上的井占总试验井数的60%;高相对分子质量高质量浓度封堵段塞注入后,试验井区注入井差层有效厚度吸液比例提高了9. 8%,试验井区采出井含水率下降幅度在1%以上的井占总试验井数的80%。在注聚合物区块停注聚合物前注入高质量浓度封堵段塞,可以有效改善聚合物驱区块注聚合物后期的开发效果。

In order to raise the development effect of polymer injection block at later stage,effect of injecting plugging slug at later stage of polymer injection was analysed.The high-concentration plugging slug was injected before stopping the injection,which can use the viscoelasticity of high-concentration polymer to further improve the effect of polymer flooding.There are two well zones in W polymer flooding industrial area that have been injected with high mass concentration slugs of both mid-molecular weight and high-molecular weight at the later stage of polymer injection,it showed that the ratio of intake liquid thickness in poor formation of injection well raised by 6.9%after injecting mid-molecular weight slug,the wells with water cut lowering more than 1%accounted for 60%of all the testing wells;and the intake liquid thickness raised by 9.8%after injecting high-molecular weight slug,the wells with water cut lowering more than 1%accounted for 80%of all testing wells.Before stopping the polymer injection,injection of high-concentration plugging slug can effectively improve the development effect at the later stage of polymer injection.