高速射流孔眼冲刷腐蚀扩孔规律实验研究

Experimental Study on Erosion of Perforation Tunnel in High Speed Jet Flow

油田压裂泵入液固两相流过程中,颗粒撞击套管射孔孔眼造成严重的冲蚀扩孔。加之腐蚀交互影响,导致孔眼直径增大,套管强度降低。基于高速液固两相流冲蚀实验,进行单孔眼流道改变流速、砂比、粒径条件下的冲蚀实验,并对冲蚀孔眼边缘进行三维轮廓扫描,探究高速射流孔眼冲刷腐蚀扩孔规律。研究表明,孔眼冲蚀速率随流速、砂比、粒径增加而增大,流速和砂比的改变对于孔眼冲蚀影响最为显著。通过建模预测携砂液注入单孔扩孔规律,得出8簇24孔施工90 min后,孔径扩张至13~19 mm,而3簇48孔施工90 min后,孔径扩张至11.7~12.8 mm。同一施工时间后,3簇48孔的孔径较小,优于8簇24孔密布孔。通过研究孔眼冲刷腐蚀扩孔规律,有助于改进各簇均衡起裂与进液施工工艺设计。

During the oilfield fracturing process,the particles impact the casing injection borehole causing severe erosion and reaming.Combined with the corrosion interaction,this leads to an increase in hole diameter and a decrease in casing strength.In this paper,based on the high-speed liquid-solid two-phase flow erosion experiment,the erosion experiment was carried out under the condition of changing the flow rate,sand ratio and particle size of the single-hole flow channel,and the three-dimensional contour scanning was conducted on the edge of the erosion hole,aiming to explore the influence rules of perforating parameters on the high-speed jet erosion hole.The results showed that the erosion rate of perforation holes increased with the increase of flow velocity and sand concentration and particle size.The flow velocity and the sand concentration had the most significant impact on the hole erosion.The single-hole expansion law was predicted by modeling and it could be concluded that the hole diameter expanded to 13mm-19mm for 8 clusters of 24 holes and 11.7~12.8 mm for 3 clusters of 48 holes within 90 min of construction time.The smaller hole diameter arrangement of 3 clusters for 48 holes was preferable to the arrangement of 8 clusters for 24 holes.Therefore,studying the law of hole erosion and expansion is conducive to improving the construction process design of equilibrium crack initiation and liquid feeding.