Patent ID: 8820396

Claim:
An ultra-high pressure (UHP) cutting device for insertion into a wellbore for cutting the casing of the wellbore from within the wellbore, the UHP cutting device comprising: a UHP hose connector for connection with a UHP hose in communication with a fluid source; a rotatable UHP tube with a top end in fluid communication with the UHP hose connector and a bottom end opposite the top end; a rotating means in operational communication with the UHP tube for rotating the UHP tube during operation of the cutting device; a cutter head in fluid communication with the bottom end of the UHP tube, the cutter head comprising: a UHP elbow for changing the direction of UHP fluid flow from a direction substantially parallel with the wellbore to a direction toward the inner surface of the wellbore; an abrasive feed port for connection with an abrasive feed line for receiving abrasive to be mixed with the UHP fluid; and a focus tube for directing the mixture of UHP fluid and abrasive out of the cutter head and toward the inner surface of the wellbore to be cut; a hollow housing situated around a majority of the length of the UHP tube, the housing fixed to a non-rotating component of the cutting device such that the housing remains stationary during rotation of the UHP tube; and a centralizer device for centering the UHP tube in the wellbore during operation of the cutting device, the centralizer device comprising: a centralizer adjustment block slidable along the housing and lockable to the housing to prevent sliding of the centralizer adjustment block when locked; an expandable centralizer rod system comprising a series of rods and hinges; centralizer adjustment rods connected at an upper end to the centralizer adjustment block and at a lower end to the centralizer rod system such that downward sliding of the centralizer adjustment block operates the hinges of the centralizer rod system and expands the outside diameter of the centralizer rod system and upward sliding of the centralizer adjustment block operates the hinges of the centralizer rod system to collapse the outside diameter of the centralizer rod system; a locking device in communication with the centralizer adjustment rods, wherein operation of the device provides for a small expansion of the centralizer rod system via the centralizer adjustment rods for locking the centralizer rod system against an inner surface of the wellbore; and a centralizer mounting bracket fixed to the housing for connection of the centralizer device to the cutting device; wherein expansion of the centralizer rod system continues until the rods of the centralizer rod system contact the inner surface of the wellbore centers the UHP tube in the wellbore.