稠油流动边界层水基泡沫减阻模拟

针对稠油水环输送的中心油流偏心问题,提出稠油流动边界层在AFS-2水基泡沫作用下的模拟实验方法,设计加工相应的管流模拟装置及泡沫发生、注入与泡沫层生成系统.用201甲基硅油模拟稠油,实验研究稠油在水基泡沫作用下的水平管流阻力特性,分析泡沫与硅油的流速与流量比对硅油流动流型和减阻效果的影响.基于上部泡沫-下部液膜复合边界层假设,建立硅油-泡沫-液膜中心环状水平管流的压降预测模型.结果表明:20℃室温下,当泡沫与硅油流量比为0.2～0.5时,硅油流动减阻率高于70%,其机理可归结为油壁间形成了上部泡沫-下部液膜的复合隔离润滑层;理论预测值与实验测量值吻合良好,相对误差为－17.55%～9.76%.

Simulation of drag reduction of aqueous foam on heavy oil flow boundary layer

According to the eccentricity of core oil flow in water-annulus transport of heavy oil, a simulated experiment for heavy oil flow boundary layer under the action of aqueous foam system-2 (AFS-2) (foam quality 50%) was proposed. A corresponding pipe flow simulated device and a system of foam generating, injecting and foam layer generating were designed and built. Flow resistance characteristics of heavy oil simulated by 201 methyl silicone oil under the action of aqueous foam in horizontal pipe were determined experimentally, and the influence of velocities and flow ratios of foam and silicone oil on silicone oil flow patterns and drag reduction was analyzed. Based on the hypothesis on complex boundary layer of upper foam-lower foam drainage film, a model for predicting pressure drop of silicone oil-foam-foam drainage film core-annular flow in horizontal pipe was established. At room temperature 20℃, drag reduction efficiency was above 70% when flow ratios of foam and silicone oil were between 0.2 and 0.5, and its mechanism of drag reduction could be the complex isolating-lubricating layer of upper foam-liquid film between oil and pipe wall. The predicted values were in good agreement with the experimental data, and relative errors were between －17.55% and 9.76%.