protective casing

基本解释

Already free of the protective casing around his foot, Rooney is walking without discomfort and will step up his training next week.
现在鲁尼脚上的保护装置已经拆除，他已经可以无障碍的走路了，下周就可以恢复训练。
The two-stage cementing technique was used for the protective casing of the horizonal well in Tahe oil field because of a long open-hole interval in secondary spudding.
塔河油田水平井由于第二次开钻裸眼段长，技术套管采用双级固井技术。
The protective casing plays the role of protecting the electronic thermometer and the electronic watch at one side face of the electronic thermometer is convenient for mastering time by people.
保护套能对电子温度计起到保护的作用；电子温度计一侧面的电子表方便人们掌握时间。
ip.com

Hydraulic fracturing involves the injection of fluid consisting of approximately 99.5% water and sand (the rest consists of common industrial or even household chemicals or materials) through wells constructed with protective casing and cement, into producing shale formations.
FORBES: Why Anti-Fracking Groups Are Shifting Their Story From Water To Air Quality