WIRED OR PORTED TRANSMISSION SHAFT AND UNIVERSAL JOINTS FOR DOWNHOLE DRILLING MOTOR

摘要

A bottom hole assembly for a drill string has a mud motor and a mandrel. The motor has a rotor driven by drilling fluid flow, and the rotor defines a bore for passage of fluid flow and/or conductors. The mandrel has a bore for passage of the conductors and/or fluid flow, and rotation of the mandrel rotates a drill bit. A shaft and universal joints transfer the drive of the rotor to the mandrel. To pass the conductors from a sonde uphole of the motor to electronics disposed with the mandrel and/or to conduct fluid flow, inner beams dispose in a bore of the shaft to seal at the ends of the shaft coupled to the first and second universal joints. Each beam has an internal passage for the conductors and/or fluid flow. One of the universal joints and inner beams compensate for eccentricity in motion of the rotor, while the other second universal joint and inner beam compensate for a bend in the downhole assembly. Each of the inner beams is at least partially flexible to compensate for articulation at the universal joints.