五里湾一区回注水与储层配伍性研究

靖安油田五里湾一区目前主要采用矿化度较低的清水作为注入水水源,而清水与储层的不配伍性造成油井见水后采液、采油指数迅速下降,采油速度降低,地层吸水能力下降,注水压力升高等问题,采用的酸化、低密度洗井及增产改造措施基本无效。另外,该区清水水源紧张,污水采出量大,直接排放会造成环境污染。针对以上问题,对该地区的储层特征、黏土矿物质量分数、岩心敏感性、注入水性质及注入水与储层配伍性对渗透率的影响等方面进行了实验研究。研究结果表明：清水与储层配伍性较差,注入后造成储层水敏损害,建议采用采出污水净化处理后回注代替清水,并在注水过程中考虑注入水的矿化度,同时可将油田注入水悬浮颗粒质量浓度和含油量的标准适当放宽到10mg·L-1以下。

Compatibility between recirculated water and reservoirs in the first district of Wuliwan

At present, the first district of Wuliwan in Jing＇an Oilfield is mainly using the lower degree of mineralization surface water as injected water, which causes the incompatibility for the reservoirs. It can lead to some troubles： rapidly descending PI, lower oil production rate, decrease of water absorbing capacity of formation, increase of water injection pressure. These problems result in the approximatively invalid acidulation, low-density hole opener treatment and essentially invalid stimulation treatments. In addition, the pollution can be induced for lacking of water supply and the voluminous extracted sewage. This paper analyzed the reservoir characteristics, content of clay mineral, sensitivity of rock core, property of injected water, influence of the compatibility between injected water and reservoirs on permeability in this district. The conclusions are obtained that the produced water reinjeetion after removal treatment is proposed for resolving the incompatibility and the water-sensitive damage of reservoirs. And water salinity must be considered in the process of injecting. In addition, the standards of suspended particle and oil content for the oil field injecting water can be relaxed to 10mg/L below.