水源井防砂复合筛管的冲蚀磨损试验研究

Experimental Study on Erosion Wear of Sand Control Composite Screen in Water Source Well

筛管是井下防砂关键器材,对防砂质量、成本和油井产量等都有很大影响,一旦筛管失效将导致水源井出砂停产,使整个防砂作业失败。为了减轻筛管的冲蚀损害,研究了各个因素对金属网布筛管和星孔筛管冲蚀损害的影响规律。结合海上油田生产实际和各种影响因素,研制了冲蚀磨损试验装置。针对2种类型的筛管,模拟了含砂粒径、流速、含砂质量分数和地层水矿化度等因素对其冲蚀的影响程度,并利用灰色关联度的方法对各个影响因素进行了排序和分析。研究结果表明:随着流体流速、粒径和含砂质量分数增加,筛管冲蚀速率增加,地层水矿化度对筛管冲蚀的影响较小;金属网布筛管的冲蚀损害因素的关联度排序为受效面积>砂粒粒径>含砂质量分数>流速;而星孔筛管的关联度排序为受效面积>含砂质量分数>砂粒粒径>流速。2种筛管的主要冲蚀因素都是受效面积,筛管的局部堵塞是造成筛管冲蚀损害的关键因素;金属网布筛管不适用于地层砂粒较粗的井;星孔筛管更适合应用于水源井这样产量较高的井。研究结果对水源井筛管的结构设计和选型具有一定的指导作用。

Screen tube, as the key equipment for downhole sand control, has great influence on sand control quality, cost and well production.The screen failure would result in sanding and shut in of the water source well, leading to failed sand control operation.To reduce the erosion of the screen, the influences of various factors on the erosion damage of the metal mesh screen and the star-hole screen are studied.Based on the actual production conditions and various influencing factors of offshore oilfields, an erosion wear experiment device was developed.For the two types of screens, the effects of sand particle size, flow rate, sand concentration and formation water salinity on the screen erosion wear were simulated.The various influencing factors were sorted and analyzed by the method of grey correlation.The results show that with the increase of fluid flow rate, sand particle size and sand concentration , the erosion rate of the screen increases.The influence of formation water salinity on the erosion of the screen tube is small.The correlation degree rank of erosion damage factor of the metal mesh screen is as follows : effective area > sand particle size > sand concentration > flow rate, and for the correlation degree rank of star hole screen: effective area > sand concentration > sand particle size > flow rate.The main erosion factor of the two kinds of screen tubes is the effective area.The partial blockage of the screen tube is the key factor causing the erosion of the screen tube.The metal mesh screen tube is not suitable for the well with coarse sand grains.While the star hole screen is more suitable for wells with higher yields such as water source wells.The study results could provide certain guidance in the structural design and selection of the water source well sand control screen.