摘要 |
Device and method for drilling into geological formations. The device comprises: a rotatable body; drilling cutters arranged on an axial end surface of the rotatable body; a percussion part, which is parallel to the rotating axis reciprocatable arranged on said body; and percussion cutters arranged on an axial end surface of the percussion part. The method comprises the steps of: bringing a percussion part with a percussive movement in contact with the formation in order to crack at least a part of the formation, and scraping the cracked parts of the formation with a drilling part.
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