Wired or ported universal joint for downhole drilling motor

摘要

A bottom hole assembly for a drill string has a mud motor (110) and a mandrel. The motor has a rotor (114) and a stator (112), and the rotor defines a bore for passage of conductors. The mandrel has a bore for passage of the conductors and for drilling fluid, and rotation of the mandrel rotates a drill bit. A shaft (130) and universal joints (140) covert orbital motion at the rotor to rotational motion at the mandrel. To pass the conductors from a sonde uphole of the motor to electronics disposed with the mandrel, an inner beam disposes in a bore of the shaft. This inner beam has an internal passage for the conductors, and seal caps dispose on each end of the inner beam to seal inside the universal joints. The inner beam and seal caps prevent drilling fluid passing from the motor and around the shaft from communicating in the shaft's bore.