| 摘要 |
Method for drilling and casing into ground 16 and installation implementing this method including : a drill string 2 comprising, at its lower end, a drill bit 4 and, near its upper end, a shoulder facing downwards; a pipe string 6 in which the drill string 2 is fitted, the upper end of the pipe string 6 being capable of receiving a thrust device 42 comprising a shoulder facing upwards and pierced with an orifice through which the drill string 2 passes; and a stop-piece placed between the said shoulders, which is capable of enabling a vertical force to be transmitted from the drill string 2 to the pipe string 6 and leaving the drill casing 2 to rotate freely with respect to the pipe string 6. <IMAGE>
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