| 摘要 |
PCT No. PCT/FR92/00179 Sec. 371 Date Dec. 14, 1992 Sec. 102(e) Date Dec. 14, 1992 PCT Filed Feb. 27, 1992 PCT Pub. No. WO92/15772 PCT Pub. Date Sep. 17, 1992.A device for measuring the movement of a drill pipe string, the end of which is held during drilling by an attachment assembly (12) movably along at least one guide rail (16), comprises a sensor assembly (38) mounted on the attachment assembly with a roller (42) designed to run on the rail as the attachment assembly moves. |
