The problems in leakage protection and executive circuit of synthetical protection set in coal electric drill have been analyzed and calculated.

通过分析和计算说明老式煤电钻综合保护装置在漏电保护和执行电路中存在的问题。

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The causes of using traditional wet drilling difficultly are analysed. And the wet drilling method of the coal electric drill of external spray hydroelectric interlock is related.

分析了传统湿式打眼难以推广应用的原因，叙述了外喷雾水电联锁煤电钻湿式打眼法。

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The hydrocarbon source rocks of coal measures developed in this basin were studied on the basis of drill cores, which involved in many fields such as geology, organic geochemistry and petrology.

根据钻井及大量的实验测试等资料，研究了侏罗系煤系烃源岩的发育特征及其有机地球化学、有机岩石学特征，表明其有机质丰度较高，达到中等-好级别； 有机质类型以Ⅲ型为主、Ⅱ型为辅；

youdao

Some of the more traditional energy producers say if you want the economy to do better, maybe take some of the regulations off in terms of making it easier to drill or to gather coal until you can develop those green energies.

WHITEHOUSE: Press Briefing

The drill also went through a coal seam at 660m that nobody knew existed.

BBC: Newcastle University borehole project strikes hot water