A CORE DRILLING APPARATUS AND METHOD FOR CONVERTING BETWEEN A CORE DRILLING ASSEMBLY AND A FULL-DIAMETER DRILLING ASSEMBLY

摘要

A core drilling apparatus adapted to be converted between a core drilling assembly and a full-diameter drilling assembly and a method enabling this. The apparatus comprises a coring drill head (200), an outer tubing (210) for conveying forces to the drill head (200), an inner tubing (220) with an upper end connected to a lifting device (230) and a lower end adapted for receiving a core sample, conveyance means (240) connected to the upper end of the outer tubing (210), and where the lifting device (230) is adapted to run between an upper and lower position within the outer tubing (210). The coring drill head (200) comprises closure elements (201) with integrated cutting implements that when in a closed or partly closed position enable the drilling head (200) to operate with full diameter drilling and with the closure elements (201) in an open position enable the drilling head (200) to operate as a coring drill head by letting rock sample pass into the inner tubing (220). The lifting device (230) comprises a release mechanism that when activated, releases forces acting on the lifting device (230), such that when the lifting device (230) is in an upper position when activated, the lifting device (230) lowers the inner tubing (220) thereby pushing the closure elements (201) in an open position, and when the lifting device (230) is in a lower position when activated, the lifting device (230) lifts the inner tubing (220) from the closure elements (201) such that the closure elements (201) will be in a closed or partly closed position.