聚合物微球有效作用距离对调剖效果的影响——以高浅南油藏为例

Effect of effective distance of polymer microspheres on profile control: a case study of Gaoqiannan reservoir

为研究非均质油藏采收率与聚合物微球运移距离的关系,优化微球注入量,利用三层非均质岩心开展不同微球注入量下的驱油、调剖实验。实验结果表明:对于非均质性较强的油藏,采用聚合物微球调剖效果显著,采收率提高幅度随微球注入量增加而增大;微球的运移倾向于优先进入高导流能力的水窜通道,在大孔道孔喉处实现聚并、架桥封堵,可有效提高后续驱油剂波及体积;微球在油藏中的运移距离对提高采收率效果影响很大,只有当微球运移至油藏深部(深调)时,才可充分发挥其调剖作用。根据高浅南油藏条件,为保证微球能够发挥深调效果,只需注入微球0.20 PV(PV为高渗层孔隙体积)。微球深调-强乳化剂驱复合技术比较适用于高浅南油藏,应用该技术可在表面活性剂驱基础上再提高采收率17.88百分点以上。

In order to study the relationship between the recovery of heterogeneous reservoirs and migration distance of polymer microspheres and optimize the injection amount of microspheres,flooding and plugging experiments were carried out in three-layer heterogeneous cores by different amount of microspheres.Experimental results show that the plugging effect of polymer microspheres is significant for strong heterogeneity reservoirs.EOR increases with the increasing injection amount of microspheres.The migration of microspheres tends to preferentially enter the water channeling with high conductivity.In the large pores and pore throat,microspheres agglomerate,bridge and plug,this can effectively improve the sweep volume.The migration distance of microspheres in reservoirs has a great influence on the recovery efficiency.Only when the microspheres migrate to the deep parts of the reservoir,profile control effect can be fully played.For Gaoqiannan reservoir,in order to ensure that the microspheres play a"deep profile control”role,just 0.20 PV injection of the high permeability layer%s pore volume is enough.The composite technology of deep profile control of microspheres and strong emulsifier flooding has good adaptability to Gaoqiannan reservoir,which can improve oil recovery by 17.88 R on the basis of surfactant flooding.