针对准噶尔盆地SN-1井区油藏存在的油井普遍高含水、部分井注水受效差以及清污混注后油水井渗透率下降等问题,开展了SN-1井区油藏水驱采收率影响因素研究。通过开展水质对岩心的伤害、岩心驱替及注水水质指标分析等室内实验和注水优化数值模拟,分别从微观尺度、岩心尺度和宏观尺度,对注入水造成的储层伤害进行了研究,揭示了导致油水井渗透率下降的伤害机理,认识到注入水中固相堵塞造成的储层伤害是导致水驱采收率低的主控因素,发现固相堵塞不仅影响微观驱油效果,还会使流度比增加,降低波及效率。因此,SN-1井区油藏回注水质不达标是注水受效差的主要因素,应将悬浮固体质量浓度作为首要水质控制指标。多尺度评价方法提高了结果的可靠性,对提高油田水驱开发效果具有指导性,可为油田稳产开发提供技术储备。

In order to solve the problems in Wellblock-SN-1 in Junggar Basin such as high water cut in oil wells, poor water injection effect in some wells, and decline in permeability of oil and water wells after water injection with wastewater and other issues, the influencing factors of water flooding recovery of reservoir have been studied. By the water injection optimization numerical simulations and experiments such as damage by the injection water to core, core flooding and injection water quality indicator analysis, the formation damage by injection water have been studied from microscopic scale, core scale and macroscopic scale respectively, and the damage mechanism leading to the decrease of permeability in production and injection wells has been revealed. It is recognized that the formation damage caused by solid blockage in injection water is the main controlling factor leading to low oil recovery. It is found that the solid blockage not only affects the microscopic flooding effect, but also increases the mobility ratio and reduces the sweep efficiency. Therefore, the water quality of the re-injection of the reservoir in Wellblock-SN-1 is the main factor for the poor water injection efficiency. The suspended solid mass concentration should be treated as the primary water quality control index. The proposed multi-scale evaluation method improves the reliability of the results, and is helpful for improving the exploitation effect of oilfield water flooding. It can provide technical reserves for stable oilfield exploitation.