聚合物驱流动压力对驱油效果的影响

Effect of flowing pressure on the oil displacement efficiency during polymer flooding

随着持续几十年的注水开发,大庆油田已逐渐步入高含水甚至特高含水阶段,油藏及流体的非均质性使优势通道更加发育,大量剩余油多集中在平面弱波及区域,如何进一步深入挖潜平面剩余油已成为矿场EOR(强化采油)的主要矛盾。在聚驱开发基础上,运用非均质油藏的数值模拟及平面物理模型的室内驱替实验,提出了控制采油井流压进一步改善平面开发矛盾的方法。研究结果表明:流压调整需充分考虑聚驱过程油墙富集的影响,在低含水期流压调整可使剩余油动用更加均匀,流压调整需考虑层内物性等因素,并形成了“含水下降期流压略微提升,低含水期反向调整,含水回升期恒定调整”的调整模式。该调整模式应用于矿场效果较好。

With the continuous development of water injection for decades,Daqing Oilfield has stepped into the stages of high watercut and even ultra-high watercut,in which the heterogeneity of the reservoir and fluid makes the dominant channels more developed,and a large amount of remained oil has been trapped in the weakly swept area on plane.Therefore,how to further tap the potential of the planar remained oil has become the principle contradiction in the field EOR.On the basis of the polymer flooding,with the help of the numerical simulation of the heterogeneous reservoirs and indoor flooding experiments of the planar physical model,the suggestion of further improving the planar development contradiction was proposed by means of controlling the flowing pressure of the oil well.The study results show that the influence of the enriched oil bank should be fully considered in the process of polymer flooding for the flowing pressure adjustment.In the low watercut period,the flowing pressure adjustment can make the remained oil producing more evenly;the adjustment needs considering the physical properties and other factors in the reservoir,and the adjustment mode has been formed,i.e.,the flowing pressure slightly increased in the watercut decline stage,reversely adjusted in the low watercut stage,and constantly adjusted in the watercut rising stage.The adjusting mode has been applied in the field with good effect.