underground safety是什么意思

用法例句

This paper briefly introduces the principle of work of subsurface safety valve,analyses present technical situation and production of domestic and foreign in the last few years and concludes development current of subsurface safety valve that develop the system of subsurface safety valve for reliable,simple structure and Intellectualization performance from now on.

介绍了井下安全阀的工作原理,对国内外的研究现状及成果进行分析,总结出井下安全阀今后的发展趋势,必须是发展性能可靠、结构简单、智能化的井下安全阀系统,并提出了几点建议。

A downhole safety valve for offshore well completion is developed.

目前国内尚没有适合海上油井完井采油的井下安全阀定型产品，为此研制出SF－1型井下安全阀。

On the Rectification and Strengthening of Underground Safety of Non-coal Mines;

论非煤矿山的井下安全整治

Treatment of underground outer source fire of coal mine;

煤矿井下外源火灾的处理

Danger analysis and management technology for underground working place of Chengchao iron mine;

程潮铁矿井下作业场所危险分析及管理技术

Research and shop tests of the downhole casing shut-off valve;

井下套管阀研究及室内试验

Theory design of downhole ultrasonic focusing system;

井下超声聚焦系统的理论设计

Preliminary approach to oil production through downhole oil-water separation technique.;

井下油水分离采油技术初探