Blank casing is usually used to clean out sand, but when bottom - hole pressure is low, this may result in no fluid flowing at wellhead and recharging of removed sand, which may affect sand removal or even lead to failure.
油田生产中,经常出现井底砂埋现象,影响采油或注水,通常的做法是下光管冲砂,但这种方法在井底压力较低时可能造成井口不返液及冲起的砂液回灌地层,影响清砂效果甚至可能造成清砂作业失败。
The results of tests show that the coarse grains, a s a results of too high casting temperature and the premature trunk opening in water explosion blast cleaning , can be eliminated by heat treatment.
试验证明,由于浇铸温度过高,水爆清砂时开箱过早而产生的粗晶可以用热处理方法消除,同时提出了铸件在浇铸时防止粗晶的措施。
The Hydraulic Cleaning Sand for Investment Castings;
熔模精密铸件的水力清砂
Review of Progress in Investment Casting Technology at Abroad Part Ⅸ:High Hydraulic Pressure Cleaning Sand and Chemical Cleaning Sand;
高压水清砂和化学清理——国外精铸技术进展述评(9)