Automatic Control System For Connecting A Dual-Member Pipe

Abstract

A system and method of making up and breaking out a dual-member drill string. The system comprises a spindle, a spindle carriage and a drive frame. The drive frame provides thrust to the spindle, while the spindle carriage provides rotation. The spindle has an outer spindle and an inner spindle, and is adapted to connect to a pipe section having an outer pipe section and an inner pipe section. Inner joints are geometrically shaped, while outer joints are threaded. When making up dual member drill string, the spindle is advanced, with the outer spindle rotating, and the inner spindle rotating in alternating directions, or “dithering.” A float sensor and a processor are used in tandem to cooperatively couple the inner spindle with the inner pipe sections and the outer spindle with the outer pipe sections.

1 . A drill string make-up system comprising:
 a drive frame;   a spindle comprising an inner spindle and an outer spindle connectable to a pipe section having an inner pipe section and an outer pipe section;   a means for providing thrust and rotation to both the inner spindle and outer spindle, wherein the inner spindle is rotatable independent of rotation of the outer spindle; and   a processor to automatically control rotation of the inner spindle 180 degrees in alternating clockwise and counterclockwise directions.