三元复合驱采出污水回注渗透率的影响因素分析

基于大庆油田三元复合驱采出污水回注对地层存在的损害现象,研究了污水回注渗透率的影响因素。采用室内水驱实验方法,对三元复合驱采出污水中悬浮物、油、碱、聚合物等因素进行了分析,阐述了各种成分对渗透率的影响机理。结果表明,悬浮物颗粒会堵塞孔隙喉道,油产生的“贾敏效应”将增大油水流动阻力,碱与岩石及黏土矿物间的物理化学作用会使地层结垢,聚合物在岩芯中的吸附和滞留共同造成地层渗透率的下降。因此,建议将三元复合驱采出污水中悬浮物、油、碱、聚合物等处理合格后再进行回注,以减轻对地层的损害。

Influence Factors Analysis of Permeability of Produced Waste Water Reinjection in Alkali-surfactant-polymer Flooding

Based on the formation damage caused by produced waste water reinjection in Alkali-surfactant-polymer(ASP)flooding of Daqing oilfield, influence factors of permeability of produced waste water reinjection are studied. The influence factors of suspended matter, oil, alkali, polymer, and so on in produced waste water reinjection were analyzed, the damage mechanism of the factors on formation is explained. The result shows that suspended matter plugs pore constriction; “Jiamin effect” caused by oil increases oil and water flowing resistance; the physical chemistry reaction among alkali, stone and clay mineral make scale formation; adsorption and retention of polymer in the core decreases the permeability of reservoir. Therefore, suspended matter, oil, alkali, polymer, and so on in produced waste water reinjection should be treated before reinjection in order to reduce the formation damage.