Mud motor with integrated percussion tool and drill bit

摘要

A downhole tool having a progressive cavity mud motor with an impact generator disposed within the mud motor rotor or bearing assembly. In one embodiment, the impact generator includes a mud turbine connected to a eccentric ring that encircles and periodically strikes an anvil surface of a percussion shaft. The eccentric ring is pivotable between an engaged striking position and a disengaged non-striking position. The percussion shaft is coupled to a drill bit though a splined connector that provides limited slip for transmitting rotation of the mud motor rotor to the drill bit and for transmitting percussion strikes against the anvil to the drill bit without the need to accelerate the entire drill string.

主权项

1. An apparatus for boring a hole in the earth comprising:
a cylindrical housing (12); a progressive cavity motor (20) disposed within said housing and having a rotor (24) rotatively captured within a stator (22), said progressive cavity motor defining a progressive cavity fluid flow path between said stator and said rotor; a bearing assembly disposed in said housing below said progressive cavity motor; an operating member (16, 99) rotatively coupled to a lower end of said housing by said bearing assembly and connected to said rotor via a transmission assembly; and a percussion assembly (72) disposed in one of the group consisting of said rotor and said bearing assembly, said percussion assembly coupled to said operating member for periodically imparting torque impulses to said operating member.