FIELD-ASSEMBLABLE BOW-SPRING CASING CENTRALIZER AND METHOD OF MAKING A CENTRALIZER

摘要

A casing centralizer is provided that may be shipped unassembled and is then assemblable at a well site. According to one embodiment, first and second collars each have a plurality of circumferentially spaced aligning slots and a corresponding plurality of threaded, extruded through-holes. A plurality of bow-springs each have a foot at each end. Each bow-spring axially extends between the first and second collars. The foot at one end of each bow-spring is disposed in one of the aligning slots of the first collar, and the foot at the other end is disposed in one of the aligning slots on the second collar. A plurality of threaded fasteners corresponding in number to the threaded extruded through-holes secure the ends of the bow-springs to the threaded extruded through-holes. The extruded through-holes have a flange height greater than a collar thickness adjacent to the extruded through-holes. The increased flange height allows more threads to be formed within the extruded holes, resulting in a stronger threaded connection with the threaded fasteners, and a correspondingly stronger, more durable centralizer. The foot is retained within the aligning slot to reinforce the coupling between the bow-spring and the collar. A method of manufacturing the casing centralizer is also provided.