balanced drilling

基本解释

Air drilling is a kind of under-balanced drilling technology with air, whose rock breaking form is different from conventional mud drilling.
空气钻井技术是以空气作为循环介质的欠平衡钻井技术，其钻头的破岩形式与常规泥浆钻井有很大的区别。
From the points of technical principles and construction flow diagram, the paper expounds the effects of under-balanced drilling on gas logging.
前言：从欠平衡钻井的工艺原理和施工流程角度出发，阐述了欠平衡钻井对气测录井的影响。
The under-balanced drilling technology is based on how to control the bottom negative pressure which is related to the pressure computation of multiphase flow in annulus .
井底负压值控制是欠平衡钻井技术的基础，而井底负压值的大小与环空多相流的有关压力计算有关。

欠平衡钻井
Air and Gas drilling is one of the most important parts of under-balanced drilling techniques, which now is being used all over the world because of its benefits.
空气钻井是欠平衡钻井的重要分支。
平衡钻井
平衡压力钻井