聚合物驱提高采收率技术在昌吉油田吉7井区的研究与应用

Research and application of EOR technology by polymer flooding in wellblock Ji-7 of Changji Oilfield

针对昌吉油田吉7井区常规水驱预测采收率偏低的现状,采用物模实验的方法研究了聚合物驱提高该区块采收率的应用潜力。实验结果表明,吉7井区储集层的渗透率级差、含水率、原油黏度等指标均能满足开展此项工艺的条件。物模实验还评价了水油流度比对提高采收率的影响。实验结果表明,三管并联岩心,水油流度比为(3∶1)～(1∶1)时,与常规水驱相比,能提高采收率5%～10%,为现场实施方案的制定提供了技术依据。在昌吉油田吉7井区5口注水井实施的聚合物驱现场试验结果表明:聚合物驱能够改善注水井的吸水剖面,控制井组含水上升速度;与常规注水井相比,能提高采收率5.5%。

The recovery rate of conventional water flooding in wellblock Ji-7 is 15%.The application potential of the polymer flooding technology in this block is studied by the method of physical model experiment.The experimental results show that the permeability of the reservoir in wellblock Ji-7 is very poor,but the water content and crude viscosity both can meet the conditions to carry out this process.The optimum ratio of water to oil fluidity is optimized and the effect of EOR is evaluated.The experimental results show that under the condition of three-pipe parallel core,the oil recovery of polymer flooding increases 5%-10%than that of conventional water flooding under water-oil mobility ratio of 3∶1 to 1∶1.The polymer flooding is carried out in 5 wells in wellblock Ji-7 of Changji Oilfield.The result of field test shows that the polymer flooding can improve the water absorption profile,and control the rising speed of water cut.Compared with conventional injection wells,the recovery factor increases 5.5%.