顶封 meaning in English

closed top
closed-top
over seal

The development and application of the upper isolation workstring
顶封封隔管柱的研制与应用
Water shutoff agent dsz - a is composed of inorganic particle . its specialities are low cost , easily flow , high strength and long valid period . the agent suits non - selective water shutoff in sand formation . dsz - a not only can plug high water - bearing formation , but also can plug case leakage . dsz - a has been applied on site and gotten good effect . it is a agent which has wide prospect
濮城油田推广应用顶封卡漏套管保护管柱,消除了环套空间水泥环窜漏影响,对漏点上部套管实施了保护,减少了无效注水,增加了有效注水,对应油井地下地质能量恢复后,增油效果明显