| 摘要 |
An oil, gas or geothermal drilling apparatus comprising a central tool and a drill bit coaxial therewith, wherein said central tool is driven by the rotor of a downhole motor supplied with drilling mud, and wherein the drill bit is driven from the surface by the string of a drill-pipe in a rotary system, with said string causing a thrust load in said apparatus. Between the stator (4) of the downhole motor and the foot (5) of the drill bit there is a prismatic linkage allowing relative axial movement of the tools, and a spring (6) is placed between the stator (4) and the foot (5) so as to be stressed by the stator when the central tool's advancing movement falls behind that of the drill bit, whereby the relative axial movement of the two tools can be controlled and the thrust load to which the apparatus is subject can be shared out between them according to said movement. The apparatus may be used in the drilling equipment industry, particularly for oil, gas or geothermal drilling.
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