Adjustable kelly bushing for downhole drilling system

摘要

A downhole drilling system utilizes a non-rotating kelly bushing for locking in the torque created in the drill string by the downhole drilling motor. The kelly bushing prevents rotational movement of the kelly secured to the drill string on which the downhole motor is attached. The kelly bushing includes a torque mechanism for enabling the kelly and the attached drill string to move in a forward direction into the hole being drilled while prohibiting any rotational movement. The torque mechanism includes a pair of rollers which are adapted to non-rotatably receive and vertically guide the kelly therebetween. The spacing between the rollers is adjustable to accommodate different sized kellys. A guide mechanism is provided in the kelly bushing for enabling an electrical wire to be attached to either the downhole motor or a sensing mechanism located in the area of the downhole motor for feeding back to the surface appropriate electrical signals indicative of certain drilling operations.