发明名称 |
Rotary drag-type drill bits and methods of designing such bits |
摘要 |
<p>The invention provides a rotary drag-type drill bit in which the relationship of torque to rotary bit speed is such that torque generally increases with bit speed. Such a bit has a reduced tendency to exhibit the phenomenon known as "stick-slip" while drilling, when compared with bits having a different torque /speed characteristic, as a result of the positive damping effect of the torque/speed relationship. One method of designing such a drill bit comprises ascertaining the torque/rotary bit speed relationship, or other correlated relationships, for a number of different drill bit designs and then selecting from those designs a design having the desired type of relationship. Examples of drill bit structures specifically designed to achieve the desired torque/speed relationship are also disclosed. <IMAGE></p> |
申请公布号 |
EP1008718(A2) |
申请公布日期 |
2000.06.14 |
申请号 |
EP19990309759 |
申请日期 |
1999.12.03 |
申请人 |
CAMCO INTERNATIONAL (UK) LIMITED |
发明人 |
TAYLOR, MALCOLM ROY;MURDOCK, ANDREW;JELLEY, DAVID JOHN |
分类号 |
E21B10/42;(IPC1-7):E21B10/46;E21B10/60;E21B10/56 |
主分类号 |
E21B10/42 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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