Flexible drill string member especially for use in directional drilling |
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| 申请号 | JP26422188 | 申请日 | 1988-10-21 | 公开(公告)号 | JPH0291389A | 公开(公告)日 | 1990-03-30 |
| 申请人 | Homco Internatl Inc; | 发明人 | GAI JIEIMUZU HIRU; HOOMAA GURAFUTON SUMISU JIYUNI; MAAKU UIRIAMU SHIYUNITOKAA; GUREN ERITSUKU BIITEI; | ||||
| 摘要 | PURPOSE: To reduce torque required to rotate a drill string by forming at least one spiral groove on a main body part of a drill string member, so that the spiral groove defines a land on the main body part during flight. CONSTITUTION: A drill string member 14 is defined by an inside diameter 28 and an outside diameter 30, and has three spiral grooves 24. Residual parts of continuous lines are called lands, and they are parts of the member 14 to make contact with a bore hole in using. Compression stress is give to a surface 32 of the bottom part of the groove 24 by shot peening, etc. Consequently, mud moves around a drill string, and it is possible to improve a stirring effect and to extensively improve efficiency of drilling work. | ||||||
| 权利要求 | |||||||
| 说明书全文 | |||||||
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