缝洞单元注水驱油可视化物理模拟研究

Study on the Visual Modeling of Water Flooding in Fractured-vuggy Unit

为了研究缝洞油藏注水驱油机理,以及注采参数对注水开发效果的影响,采用可视化物理模拟的方法研究了注采井位、注水强度对缝洞型油藏剩余油分布、含水率、采收率的作用机制。同时进行了单相物"理模拟实验和注气提高采收率实验。研究发现:注采井位对水驱油效果产生明显影响,底部注水的采收率高于顶部注水。低流速范围内,无论注水井位置如何,重力对油水置换都起到积极的作用。在一定的流速范围内,注入速度越大,注入压力越大,生产井见水略早,含水采油期越长,采收率越高。单相物理模拟实验,在低流速范围内注入压力与注入速度成线性关系;在高流速范围内注入压力与注入速度成非线性关系。研究结果表明:注气可以有效地驱替缝洞中的剩余油,特别是对阁楼油和绕流油效果显著。

In order to study the water flooding mechanism and how the injection-production parameters affects water flooding development in fractured-vuggy reservoir,the physical conditions and the visual physical simulation were determined on the basis of the analogy theory and the site materials of oilfields.The visual physical simulation was used to intuitively understand the mechanism bottom water intensity and the injection-production position act on residual oil distribution,water content and oil recovery.At the same time experiments on simulation of single-phase and gas injection enhanced oil recovery were conducted.The results show that injection-production position has a significant impact on water flooding effect and recovery rate of water injection at the bottom is higher than the top.In the low flow rate range,gravity plays a positive role on the oil-water displacement regardless of the water injection position.Within the certain scope of the injection rate as injection flow rate increases,the injection pressure gets higher,the water breakthrough gets a little earlier,the water-cut oil production period gets longer,the oil recovery rate gets higher.In the low velocity range,injection pressure and injection rate is a linear relationship,in the high velocity range,injection pressure and injection rate is a nonlinear relationship.The result shows that the gas injection effectively displace residual oil in seam hole and the effect is remarkable especially for attic oil and bypass oil.This has important guiding significance for enhancing recovery in factured-vuggy carbonate reservoir.