Torque shoulder of a premium connection

Abstract

A threaded tubular connection includes a pin having external threads, a pin seal surface, and a pin torque shoulder at a free end and a box for receiving the pin, a box seal surface for contacting the pin seal surface and a box torque shoulder for contacting the pin torque shoulder. The pin torque shoulder has a curved pin shoulder surface. The box torque shoulder has a curved box shoulder surface.

1 - 15 . (canceled) 
     
     
         16 . A threaded tubular connection comprising:
 a pin, the pin having external threads, a concave pin seal surface, and a pin torque shoulder at a free end; and   a box for receiving the pin, the box having internal threads for interacting with the external threads, a convex box seal surface for contacting the concave pin seal surface and a box torque shoulder for contacting the pin torque shoulder,   the pin and box defining a longitudinal axis,   the pin torque shoulder having at least one pin shoulder surface having a pin radius, the at least one pin shoulder surface being curved with respect to the longitudinal axis,   the box torque shoulder having at least one box shoulder surface having a box radius, the at least one box shoulder surface being curved with respect to the longitudinal axis.   
     
     
         17 . The threaded tubular connection as recited in  claim 16 , wherein the pin radius is complementary to the box radius. 
     
     
         18 . The threaded tubular connection as recited in  claim 16 , wherein the pin torque shoulder or box torque shoulder have a bullet, fishtail or bull nose shape. 
     
     
         19 . The threaded tubular connection as recited in  claim 16 , wherein the at least one pin shoulder surface includes a plurality of pin shoulder surfaces, each pin shoulder surface having a corresponding pin radius. 
     
     
         20 . The threaded tubular connection as recited in  claim 19 , wherein the corresponding pin radii are different. 
     
     
         21 . The threaded tubular connection as recited in  claim 19 , wherein the corresponding pin radii are the same. 
     
     
         22 . The threaded tubular connection as recited in  claim 16 , wherein the at least one box shoulder includes a plurality of box shoulder surfaces, each box shoulder surface having a corresponding box radius. 
     
     
         23 . The threaded tubular connection as recited in  claim 22 , wherein the corresponding box radii are different. 
     
     
         24 . The threaded tubular connection as recited in  claim 22 , wherein the corresponding box radii are the same. 
     
     
         25 - 28 . (canceled)