| 主权项 |
1. An apparatus for cutting a wellbore, the apparatus comprising:
a motor having a stator and a rotor, the rotor comprising an output shaft connected to a cutting structure so as to drive the cutting structure in use, wherein the stator and rotor are spaced radially outwardly of the axis of rotation of the rotor such that at least one of the stator and the rotor is formed with an access bore that extends through the motor to a position adjacent the cutting structure and through which, in use, a further object can pass, without obstruction from the stator and rotor such that the stator and rotor do not therefore require drilling out or removal to allow the further object access to the cutting structure, the motor coupled to a lower end of a wellbore tubular; and a flow diverter disposed in the motor proximate a connection between the motor and the wellbore tubular, the flow diverter having a first fluid outlet in fluid communication with a power section of the motor, the flow diverter having a second fluid outlet in fluid communication with the access bore, the second fluid outlet configured such that a lowered pressure at a fluid outlet of the motor is also present at a cross section of an upper part of the output shaft, the flow diverter coupled to the stator and having a piston area related to an equivalent piston area of the motor such that axial loading created by fluid pressure is substantially transferred to the stator. |
