Method for manufacturing a flush/semi-flush threaded connection

Abstract

A method for manufacturing pipe joints for connecting two pipe sections in a well bore allows the pipe joint to have increased resistance to compressive and torsional forces. Each pipe joint has a box member for matingly engaging a pin member, the pin member being threadingly connected to the box member to create the pipe joint. Threads are created for the pin member on a tapered exterior surface of a pipe, the threads being axially disposed between a pin end terminal surface and an external shoulder. A tapered surface having a recess is created for the box member on an interior of a pipe, the tapered surface being axially located between a box end terminal surface of the pipe and an internal shoulder, the recess being axially located just behind the box end terminal surface of the pipe. Threads are cut into the tapered surface of the box member, the threads beginning behind the recess and traveling axially away from the box end terminal surface. Since the threading pass for the box member begins behind the recess, threads are not cut through the box end terminal surface giving, this surface an increased contact area. When the pin member and the box member are threadingly connected, the box end terminal surface engages the external shoulder of the pin member. The increased area of the box end terminal surface gives the pipe joint increased compressive and torsional resistance.