Drill collar |
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| 申请号 | US29827763 | 申请日 | 1963-07-29 | 公开(公告)号 | US3237427A | 公开(公告)日 | 1966-03-01 |
| 申请人 | REED ROLLER BIT CO; | 发明人 | SCARBOROUGH WILLIAM E; | ||||
| 摘要 | |||||||
| 权利要求 | 1. A DRILL COLLAR CONNECTABLE AT ITS UPPER END INTO A ROTARY DRILL STRING, AND CONNECTABLE AT ITS LOWER END TO A DRILLING BIT, SAID DRILL COLLAR HAVING A SUBSTANTIALLY SQUARE CROSS-SECTIONAL PORTION WITH ROUNDED CORNERS IMMEDIATELY ABOVE SAID BIT, AND HAVING A GENERALLY CYLINDRICAL CROSS- |
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| 说明书全文 | |||||||
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