发明名称 |
CONCENTRIC PIPE DRILL STRING |
摘要 |
This invention contemplates stands of concentric drill pipes with tool joints which are disconnectable from the pipes for use in oil well drilling. The removable tool joints provide means for supporting and maintaining the inner tube in coaxial relationship within the surrounding outer pipe within each stand.
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申请公布号 |
US3664441(A) |
申请公布日期 |
1972.05.23 |
申请号 |
USD3664441 |
申请日期 |
1970.06.01 |
申请人 |
CAREY MACHINE AND SUPPLY CO. |
发明人 |
PAUL P. CAREY |
分类号 |
E21B17/04;E21B17/18;(IPC1-7):E21B43/00;E21B21/00 |
主分类号 |
E21B17/04 |
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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