Integrated inspection and maintenance raise boring method and an associated drill string arrangement

Abstract

A raise boring method is disclosed including the steps of cutting a raise with a raise boring arrangement comprising a surface-mounted drilling unit from which a hollow drill string, comprising a plurality of hollow drill pipes fitted together, extends downwardly through a pre-drilled pilot hole, with a reamer head to cut the raise being fitted to the end of the drill string; stopping the cutting process; lowering a cable through the hollow drill string towards the bottom of the raise; fitting an inspection device at the bottom of the raise to the cable extending through the hollow drill string, the inspection device comprising a controller to receive data obtained by the inspection device; operating the inspection device so as to inspect the side wall below where the reamer head is cutting; communicating the data obtained by the inspection device to an inspection station; and determining whether maintenance is required on the side wall.

1 . A raise boring method comprising:
 cutting a raise with a raise boring arrangement comprising a surface-mounted drilling unit from which a hollow drill string, comprising a plurality of hollow drill pipes fitted together, extends downwardly through a pre-drilled pilot hole, with a reamer head to cut the raise being fitted to the end of the drill string;   stopping the cutting process;   lowering a cable through the hollow drill string towards the bottom of the raise;   fitting an inspection device at the bottom of the raise to the cable extending through the hollow drill string, the inspection device comprising a controller to receive data obtained by the inspection device;   operating the inspection device so as to inspect the side wall below where the reamer head is cutting;   communicating the data obtained by the inspection device to an inspection station; and   determining whether maintenance is required on the side wall, and if maintenance is required, the method further comprises:
 removing the inspection device from the cable; 
 fitting a maintenance device at the bottom of the raise to the cable; and 
 operating the maintenance device so as to perform the required maintenance on the side wall. 
   
     
     
         2 . The raise boring method of  claim 1 , wherein, after the maintenance performed by the maintenance device, the method comprises removing the maintenance device from the cable and then either refitting the inspection device to the cable to inspect the maintenance work or, after raising the cable back up through the drill string, allowing the raise boring arrangement to continue cutting. 
     
     
         3 . The raise boring method of either  claim 1  or  claim 2 , wherein the step of operating the inspection device so as to inspect the side wall comprises raising and lowering the cable and/or rotating the inspection device, or at least an inspection component of the inspection device, through 360°, so as to inspect the entire side wall. 
     
     
         4 . A hollow drill string arrangement that can be secured to a raise boring arrangement for cutting a raise, the raise boring arrangement comprising a surface-mounted drilling unit from which the hollow drill string extends downwardly through a pre-drilled pilot hole, with a reamer head to cut the raise being fitted to the end of the drill string, the drill string arrangement comprising:
 a plurality of hollow drill pipes fitted together; and   a cable that can extend through the plurality of hollow drill pipes, the cable being connectable to either an inspection device for inspecting the side wall below where the reamer head is cutting or a maintenance device for performing any required maintenance on the side wall.   
     
     
         5 . The hollow drill string arrangement of  claim 4 , wherein the cable is a hoisting cable to mechanically connect the inspection and maintenance devices to an actuating device on the ground to raise and lower the devices as required. 
     
     
         6 . The hollow drill string arrangement of  claim 4 , wherein the cable is an integral data and hoisting cable to not only mechanically connect the inspection and maintenance devices to an actuating device on the ground to raise and lower the devices as required, but also to allow data communication between the devices and an inspection station. 
     
     
         7 . The hollow drill string arrangement of  claim 6 , wherein the integral data and hoisting cable comprises:
 a support cable to support the device;   a data network cable to facilitate communications between the shaft device and the inspection station; and   a power conducting cable to conduct electrical power to the device.