摘要 |
An apparatus (5) for cutting a wellbor (1) is disclosed, the apparatus (5) comprising a motor provided with a stator (13) and a rotor (11), the rotor (11) being connected to to a cutting structure (7) so as to drive the cutting structure (7) in use, wherein the stator (13) and rotor (11) are spaced radially outwardly of the axis of rotation of the rotor (11) such that at least one of the stator (13) and the rotor (11) is formed with an access bore (15) that extends through the motor to a position adjacent the cutting structure (7) and through which, in use, a further object (17) can be inserted, without obstruction from the stator (13) and rotor (11). Examples of the cutting structure include a drill bit, a reaming shoe, or a coring tool operative to cut a sample core for subsequent analysis. |