高盐油藏开发期饱和度计算的矿化度驱替-交换模型

摘要

The salinity change of mixed liquid in reservoir is controlled by injection water displacement and ion exchange during water-flooding.In the initial stage of flooding,the change is mainly affected by the proportion of injected wate in pore volume;with the increase of water injection time and water injection volume,the degree of ion exchange between injected water and primary water is also increasing.The displacement-exchange theory model of salinity is proposed for the first time,and the relationship charts between the salinity of the mixed fuilds and the current oil saturation,the salinity of primary water,as well as the salinity of the injected water are established.Moreover,the change rule of resistivity during waterflooding is also simulated. Based on the theoretical model,charts and electrical logging,iterative computation or joint problem-solving method is used to eliminate the multi-solution problem in the calculation of the remaining oil saturation,w hich improve the calculation accuracy of saturation and salinity.T his method has achieved good results in the interpretation of w ater flooded layers in multiple large and medium-sized reservoirs.%注水开发过程中油藏混合液矿化度的变化受注入水驱替和离子交换控制.水淹初期,矿化度变化受孔隙体积中的注入水比例影响;随着注水时间和注水倍数增加,注入水和原生水之间的离子交换程度不断增加.首次提出矿化度驱替-交换理论模型,确定出混合液矿化度与目前含油饱和度、原生水矿化度、注入水矿化度的关系图版,模拟研究水淹过程中电阻率的变化规律.利用这一理论模型和图版,结合电法测井,采用迭代计算或联合求解的方法,消除剩余油饱和度计算中存在的多解性问题,提高饱和度和矿化度的计算精度,在多个大中型油藏水淹层解释中取得良好的应用效果.