This allows the bit to drill around a central cylinder of rock, which is taken in through the bit and into the core barrel.
这样允许钻头围绕岩石的中心圆柱体钻进，并通过钻头进入取芯桶。
To drill soft, unconsolidated, usually shallow formations by eroding the "rock" below the bit by hydraulic impact loading alone.
钻进松软、非固结，通常是浅地层时，通过仅仅依靠液力冲击载荷去冲蚀破碎钻头下的岩石。
Single pass drilling apparatus, use a one-piece drill bit, method and rock bolt for single pass rock bolting.
单通道钻孔装置，整个钻头的使用，用于单通道岩石锚固的方法和岩石锚栓。
Insert tooth bit applies in every serious geography especially hard rock; it has stable drilling speed and can drill the hardness of rock at 1-6 grades.
镶齿牙轮钻头主要适用于地质较硬的岩层，它钻进速度稳定，可以钻进1-6级地质硬度，适用于各种恶劣的地质环境。
The drill bit is a direct tool for rock breakage. The rate of penetration is closely related with the drill bit as well as the mechanical properties of the rocks.
钻头是直接破碎井底岩石的工具，钻井速度的快慢不仅与钻头有关，而且与所钻岩石的力学性质密切相关。
A drill bit used for obtaining core samples in concrete or rock formations.
钻头被用来在水泥或岩层获取岩芯样品。
Diamond cone bit is a new drill bit which make use of cutting cutters interacting with rock slowly and alternately.
轮式金刚石钻头是利用切削齿缓慢交替切削运动来破碎岩石的新型钻头。
Igneous rock stratum in Daqing is the world-class difficult drilling formation. The rock drilled in the stratum have high drillability value and poor adaptability with drill bit.
大庆油田火成岩地层是世界级难钻地层，钻进过程中该地层岩石表现为可钻性值极高，地层与钻头适应性差。
They supply plentiful useful information for the design and function of the integral PDC drill bit, while stating the principle of destroying the rock of the integral PDC drill bit.
对复合钻头的几何设计和性能设计提供了丰富的、有用的信息，同时叙述了组合钻头的破岩原理。
For soft rock, the hard rock, hard rock and other strata, multi-point drill bit broken efficient.
适用于轻型回转钻机钻进软岩、中硬岩、硬岩等各类地层，钻头采用多点破碎，效率较高。
Our research demonstrate that the drill string vibration is forced vibration, it needs to consider the rock-drill bit-drill string-swivel as the "drill string vibration system";
研究认为钻柱振动是一受迫振动问题，需要将井底岩石-钻头-钻柱-水龙头作为一个“钻柱振动系统”来对待；
Our research demonstrate that the drill string vibration is forced vibration, it needs to consider the rock-drill bit-drill string-swivel as the "drill string vibration system";
研究认为钻柱振动是一受迫振动问题，需要将井底岩石-钻头-钻柱-水龙头作为一个“钻柱振动系统”来对待；
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