COMPOSITE DRILL PIPE AND METHOD OF FORMING SAME

摘要

A lightweight and durable drill pipe string capable of short radius drilling formed using a composite pipe segment formed to include tapered wall thickness ends that are each defined by opposed frustoconical surfaces conformed for self aligning receipt and intimate bonding contact within an annular space between corresponding surfaces of a coaxially nested set of metal end pieces and a set of nonconductive sleeves. The distal peripheries of the nested end pieces and sleeves are then welded to each other and the sandwiched and bonded portions are radially pinned. The composite segment may include imbedded conductive leads and the axial end portions of the end pieces are shaped to form a threaded joint with the next pipe assembly that includes contact rings in the opposed surfaces of the pipe joint assembly, the contact of which is effected by either piercing with a pointed contact from one end into the other to connect the corresponding leads across the joint or contacting opposed rings in each end.