Patent ID: 6543132
Filing Date: 2003-04-08
Classification: B21C,C23C,E21B,F04C,Y10T

Abstract:
A method of making a stator housing having a desired inner profile and with a substantially uniform outer diameter for use in drilling wellbores, comprising:(a) providing a metallic hollow tubular member that is to be transformed to a stator housing having an inner surface and the desired inner profile along an axial direction of the metallic hollow tubular member, the desired profile including at least one lobe: (b) placing a mandrel inside the metallic hollow tubular member, said mandrel having an outer contoured surface that corresponds to the desired inner profile of the stator housing; and (c) applying compressive force on the outside an outer surface of the metallic hollow tubular member by at least two rollers to compress the metallic hollow tubular member toward the mandrel to reduce the overall outer diameter of the metallic hollow tubular member until the inner surface of the metallic hollow tubular member attains the profile defined by the outer profile of the mandrel and the outer surface is substantially uniform in diameter.