挡砂介质变形及挡砂精度变化规律研究

Study on Sand Control Screen Media Deformation and Sand Retention Precision

关于挡砂介质在热采条件下的变形特性以及对挡砂精度的影响规律少有研究。为此,分析了挡砂介质的主要结构类型以及不同金属材料在高温下的线膨胀系数的变化规律;以此为基础,分析割缝缝隙类、绕丝缝隙类和金属滤网类这3种挡砂介质的几何结构模型,建立了高温条件下的介质变形特性及挡砂精度预测模型,分析了不同结构参数下筛管挡砂精度变化规律。分析结果表明:随着温度升高,完全约束条件下的割缝衬管和绕丝筛管的挡砂精度明显降低;360℃条件下绕丝筛管挡砂精度降低幅度小于5%,而割缝衬管挡砂精度降低幅度高达25%,并且割缝间距越大,挡砂精度降低幅度越大;随温度上升,滤网类筛管挡砂精度取决于滤网金属丝直径和原始网孔的相对大小,但变化幅度不超过1%。研究结果可为热采井防砂设计提供指导。

Few study has been focused on sand retaining medium deformation characteristics during thermal production and their influence on the sand retaining precision.The main structure of sand retention medium and the linear expansion coefficient of different metal materials at high temperatures have been analyzed.The geometry model of three different sand retaining medium of slotted liner,wire-wrapped screen and metal mesh screen have been analyzed.The media deformation characteristics at high temperature and sand retaining precision forecasting model have been established to analyze the law of sand retention precision of sand screen with different structural parameters.The results show that,with temperature increasing,the sand retention precision of slotted liner and wire-wrapped screen under fully constrained condition decreased obviously.At 360℃,the wire-wrapped screen precision has a reduction of less than 5%,while the slotted linear precision has a reduction of up to 25%.The greater the slot spacing,the greater the reduction of sand retention precision.As the temperature rises,the sand retention precision of filter screen depends on the metal wire diameter and the relative initial mesh size,but the magnitude of change is not more than 1%.