浅层砂岩油藏高含水后期聚驱参数优化研究

Optimization of Polymer Flooding Parameters in High Water Cut Sand Production Reservoirs

高含水后期的浅层疏松砂岩油藏出砂问题严重,常规的聚合物驱已经不能有效控制储层的含水上升速度,油井产量递减较快。针对这一难题,以济阳凹陷S区块为例,通过数值模拟优选多段塞组合聚驱参数,制定了一套适应浅层疏松砂岩储层的多段塞组合的注聚方案。结果表明,与常规砂岩储层聚合物驱相比,该方案用量30%的聚合物前置高浓度段塞有效地缓解了地层平面矛盾,同时后续注入较低浓度的聚合物缓解地层出砂对聚驱效果的影响,取得了较好的控水增油效果。综合含水率下降7%,阶段增油量101.67×10^(4)m^(3),与原始水驱相比,采收率提高6.35%。

Sand production is a serious problem in shallow unconsolidated sandstone reservoirs at the late stage of high water cut.Conventional polymer flooding can no longer effectively control the rising rate of water cut in the reservoir,and the oil well production declines rapidly.To solve this problem,taking Block S in Jiyang depression as an example,the parameters of multi slug combination polymer flooding are optimized by numerical simulation,and a set of multi slug combination polymer injection scheme is formulated,which is suitable for shallow unconsolidated sandstone reservoir.Practice has proved that the high concentration slug can effectively alleviate the horizontal contradiction of the formation in front of the polymer with a dosage of 30%in this scheme,compared with conventional polymer flooding in sandstone reservoir.At the same time,the subsequent injection of low concentration polymer can alleviate the impact of formation sand production on the effect of polymer flooding,and achieve a better effect of water control and oil increase.The comprehensive water content decreased by 7%,with the stage oil increase of 101.67×10^(4)m^(3),which is 6.35%higher than the original water drive.It provides a reference for polymer flooding development of shallow unconsolidated sandstone reservoirs of the same type.