This paper deals with the design, research and application of a kind of new technique on the big hole perforation in oil well and forming fissure in oil layer.

论述了一种大孔径射孔造逢新技术的设计、研究及应用 ，该技术特别适用于稠油常规开采。

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If your ERCP included a therapeutic procedure such as removal of stones or placement of a stent (drain), there are additional small risks of bleeding or perforation (making a hole in the intestine).

如果要通过造影进行治疗，比如结石清除或者放置支架引流，还要考虑出血或者肠穿孔的风险。

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The law conversation of energy and the hole diameter formula of jet perforating are employed to deduce the relationship of diameter and velocity of jet for cylindrical hole of perforation concrete.

文中根据能量守恒原理及侵彻孔径公式，推导了获得圆柱形穿孔的射流直径与速度的关系。

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