聚合物微球油藏适应性评价方法及调驱机理研究

摘要

Researches on reservoir adaptability evaluation methods of polymeric microsphere and its flooding mechanism were carried out,taking reservoir geology and fluid property of typical area in Daqing as research platform,regarding injection pressure,moisture content and oil recovery efficiency as evaluation index.Results show that,with the extension of hydration time,the expansion times(Q) increases,the early expansion rate is faster,and after inflation rate is slow.Compared with the SMGw,the Q growth of SMGy is slow and Q is small.Compared with the polymer molecule aggregate,the size distribution of microspheres is narrow,so the inaccessible pore volume of microspheres is greater than that of the polymer solution.When polymeric microsphere samples SMGw and SMGY pass core and injection pressure reaches a steady,the permeability limitation is 237 ×10-3 μtm2 and 712 × 103 μtm2.Microspheres flooding mechanism is different from polymer flooding,displacement move into the larger pores and the sealing action,and the water enters the smaller pores and drives the oil.Microspheres constant-pressure experiment of recovery growth is greater than constant rate experiment,microspheres (Ⅳ) model of profile modification and oil displacement effect is superior to the effect of polymer flooding (Ⅱ) model.%以大庆油田储层和流体物性为模拟对象,采用注入压力、含水率和采收率等评价指标,对聚合物微球油藏适应性评价方法及调驱机理进行研究.实验结果表明,随着水化时间的延长,微球吸水膨胀倍数(Q)增加,初期膨胀较快,之后膨胀减缓.与SMGw相比,SMGY的Q增长较慢,Q较小.与聚合物相分子聚集体尺寸相比,SMGw和SMGY微球状态粒径分布范围都较窄,具有更大的不可及孔隙体积.聚合物微球SMGw和SMGY通过岩心时,压力达到稳定时的岩心渗透率极限值为237×10-3μm2和712×10-3μm2.聚合物微球调驱的调驱机理与聚合物驱不同,微球进入较大孔隙滞留和产生封堵作用,水进入较小孔隙发挥驱油作用.微球恒压实验的采收率增幅大于恒速实验的值,聚合物微球调驱(模型Ⅳ)的增油效果要优于聚合物驱(模型Ⅱ)的增油效果.