提液措施对聚驱效果的影响

THE EFFECT OF LIFTING FLUID ON POLYMER FLOODING

油藏数值模拟是研究聚合物驱影响因素的重要手段之一。利用数模方法建立一注四采典型模型,研究聚驱合理的提液时机、不同渗透率级差对提液效果的影响程度以及提液对油井剖面改善情况的影响,为油田提供聚合物驱动态调整依据及有效手段。研究认为:无论单层还是多层非均质地层,聚驱时提液的增油效果均好于聚驱不提液的效果,提高采收率7．25％～8．77％;多层非均质地层比单层聚驱效果差;纵向渗透率2倍级差和5倍级差时,提液最佳时机为整体见效后;10倍级差时,注聚时提液和见效时提液效果相同;对于纵向非均质程度高的地层,高峰期后提液不利于扩大中低渗透层波及体积。

Reservoir numerical simulation is one of important method of studying performance factor of polymer flooding. For four production wells and one injection well, we have established one typical model by using numerical simulation method to study reasonable opportunity of lifting fluid and effect degree of lifting fluid and production well section improvement with different permeability max-min ratios, provided dynamic adjustment basis and effective means for oilfield polymer flooding. Results have shown that increase of fluid volume can produce more oil than fixed liquid volume during polymer flooding, enhance oil recovery 7. 25% ~ 8. 77% , regardless of in monolayer or aeolotropic multiplayer formation. Effect of polymer flooding on monolayer formation is better than in aeolotropic multiplayer formation when max - min ratio of vertical permeability is equal to two or five times, and optimal time of volume increase is after appearing whole effect; whereas equal to ten times, effect of increase liquid volume during injecting polymer is the same as after appearing effect. For heterosphere, volume increase makes against enlarging the volume in the expansion in mid-low penneability layer after high production.