发明名称 |
Bi-centered drill bit having enhanced casing drill-out capability and improved directional stability |
摘要 |
A bi-center drill bit is disclosed which includes a bit body having pilot blades and reaming blades distributed azimuthally around the body. The blades have cutting elements disposed thereon at selected positions. The body and blades define a longitudinal axis of the bit and a pass-through axis of the bit. In one aspect, selected ones of the pilot blades include thereon, longitudinally between the pilot blades and the reaming blades, a pilot hole conditioning section including gage faces. The gage faces define a diameter intermediate a pilot hole diameter and a pass-through diameter defined, respectively, by the pilot blades and the reaming blades.
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申请公布号 |
US6659207(B2) |
申请公布日期 |
2003.12.09 |
申请号 |
US20010874922 |
申请日期 |
2001.06.05 |
申请人 |
SMITH INTERNATIONAL, INC. |
发明人 |
HOFFMASTER CARL;BEATON TIMOTHY P. |
分类号 |
E21B10/26;E21B10/42;E21B10/43;(IPC1-7):E21B10/40 |
主分类号 |
E21B10/26 |
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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