PDC cutter size, back rake and density are very important design parameters affecting the performance of PDC bit.

PD C切削齿尺寸、后倾角和布齿密度是影响PD C钻头性能的重要设计参数。

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The laying position and well blowout pressure are analyzed and discussed briefly and the relationship curve of drill bit pressure drop vs flowrate and fluid density i.

对其安放位置及井喷压力进行了简要分析和探讨，建立了钻头压降与流量、流体密度的关系曲线。

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The deep formation has a high degree of hardness and abrasivity; the bit type selection is difficult and the ROP is low especially under the high density mud.

深部井段地层的硬度高、研磨性强，钻头选型困难，特别是在高密度条件下机械钻速低。

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s And if we go ahead and superimpose the 3 s on top of the 3 p, you can see that the 3 s actually has some bit of probability density that gets even closer to the nucleus than the 3 p did.

如果我们继续将,重叠到3p上面，你们会看到3s事实上,有一点概率密度,距离原子核更近,比3p轨道。

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