| 摘要 |
A drilling system for drilling underground boreholes, includes a tool body 10; a downhole motor 16; a drill bit 18 mounted on the body 10 to be driven by the motor 16; a mechanism for driving the tool body axially along the borehole so as to apply weight on the drill bit 18 when drilling; and an electrical cable 14 extending from the surface to the tool body 10 to provide power for the drilling motor 16. The tool body 10 includes a conduit 22 connected to the drill bit 18 such that drilled material passes from the drill bit 18 through the conduit 22, and sensors 24 are provided in the conduit 22 for measuring properties of the drilled material. The drilling system may also be used to drill cores and the measured properties can be used to provide detection of gas licks and abnormal cuttings size. |
