Torque position make-up of tubular connections

Abstract

Threaded pipe sections are connected to form a tubular joint having proper sealing positioning at proper make-up torque. This improved connection includes a first pipe section having a registry mark of a prescribed width at a predetermined position on its exterior surface for the proper axial engagement of the pin member with the coupling or box member. This position is principally determined from finite element analysis. This position is the same for all pin members of a similar size, grade, weight and thread form and therefore can be applied with a template. The pin member and box member are continuously threaded together up to a minimum of an empirically predetermined torque range. This torque range is predetermined by a combination of finite element analysis and experimentation of representative joints for a certain type, size, weight and grade of pipe section. If required, the range is adjusted by empirically determined friction factors to account for different platings, surface treatment and lubricants. While inexpensive, this improvement provides a simple method to visually determine on the rig floor or at the pipe rack whether the joint is properly made up to thereby provide effective sealing of the API tapered threaded joint.