水驱油田特高含水期含水率预测模型

Water-Cut Prediction Model of Waterflooding Oilfield with Extra-High Water-Cut

室内实验和矿场实践表明,在水驱油田特高含水期,现有相对渗透率方程不能准确描述油水相对渗透率比值随含水饱和度的变化关系,致使以该方程为前提建立的含水率预测模型在水驱油田开发后期的预测结果产生较大偏差。针对该问题,结合中国大多数水驱开发油田已进入特高含水期的生产实际,提出新型相对渗透率曲线表征方程,利用实际油田的相对渗透率数据,采用最小二乘法进行验证。在此基础上,借助新型相对渗透率表征方程和物质平衡原理,建立适应于特高含水期的含水率预测模型,通过油田实际生产测试资料验证了新模型的实用性和有效性。结果表明,新含水率预测模型的精度高于常用的Logistic模型及Gompertz模型,对特高含水期的含水率动态预测及开发规律认识具有一定的指导意义。

Laboratory experiments and field practice show a different function between oil-water relative permeability ratio and water saturation from that of available relative permeability equation,which generally leads to a relatively great deviation for the water-cut prediction in the late stage of oilfield development by the water-cut prediction model based on available relative permeability equation. Due to most of waterflooding oilfields in China have stepped into extra-high water-cut stage,a new relative permeability equation is proposed to improve the water-cut prediction in extra-high water-cut stage. Field actual relative permeability data and least square method are used to verify this relative permeability equation. On this basis,the new relative permeability equation and material balance principle are used to establish a water-cut prediction model for extra-high water-cut stage. The corresponding practicality and validity of this prediction model are verified by using field production and test data. Research shows that the new water-cut prediction model gains higher prediction accuracy than that of Logistic Model and Goempertz Model,which could provide certain guidance for the water-cut prediction and development in extra-high water-cut stage.