drill string blowout preventer是什么意思

用法例句

Analysis of laying position of new inner blowout preventer;

新型内防喷器安放位置分析

A new inner blowout preventer is developed and the industrial test and theoretical study are finished.

开发设计了一种新型内防喷器,并完成了工业性试验和理论研究工作。