| 主权项 |
1. A drilling apparatus comprising:
a sonde housing that is elongated along a central longitudinal axis, the sonde housing having a length that extends along the central longitudinal axis from a proximal end of the sonde housing to a distal end of the sonde housing, the proximal end of the sonde housing being adapted for connection to a drill string and the distal end of the sonde housing including a distal end face, the sonde housing further defining first and second sonde-housing fluid-delivery passages, the first and second sonde-housing fluid-delivery passages extending fluidly separately from one another throughout substantially an entire length of the sonde housing; and a rotary cutting tool that mounts to the distal end of the sonde housing, the rotary cutting tool further defining distinct first and second cutting-tool fluid-delivery passages, the first sonde-housing fluid-delivery passage being in fluid communication with the first cutting-tool fluid-delivery passage, the second sonde-housing fluid-delivery passage being in fluid communication with the second cutting-tool fluid-delivery passage. |
