| 摘要 |
The present invention relates to a device for drilling wells which comprises a platform 10, the peripheral case of which has a cross-section which is less than that of the well to be drilled, an excavator 100 suspended from the platform and a plurality of sole plates 50 mounted so as to move on the platform 10 between an extended position in which the sole plates 50 project on the periphery of the platform in order to bear on the internal surface of the well, and immobilise the drilling device at a selected height in the well, and a retracted position enabling the drilling device to move vertically in the well. The invention also relates to a drilling method employing this device. <IMAGE>
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