Tubular connection control using detectable feature

Abstract

A tubular string can include helical threads on respective tubulars, and a structural formation on at least one of the threads. The formation is configured to produce a change in torque as the threads are threaded together. A method of making up a threaded connection between tubulars can include producing a structural formation on at least one of threads of the respective tubulars, engaging the threads, and applying torque to the threaded connection, thereby causing the tubulars to shoulder up. The formation causes a change in the torque a predetermined number of turns prior to the shoulder up.

1 . A tubular string for use with a subterranean well, the tubular string comprising:
 first and second helical threads respectively formed on first and second tubular members; and   a structural formation on at least one of the first and second threads, the formation configured to produce a change in torque as the first and second threads are threaded together, in which the first tubular member is configured to form a pressure-tight seal directly with the second tubular member when the first thread is fully engaged with the second thread.   
     
     
         2 . The tubular string of  claim 1 , in which the formation is further configured so that the change in torque is produced a predetermined number of turns from a shoulder up of the first and second tubular members. 
     
     
         3 . The tubular string of  claim 1 , in which the formation is further configured so that the change in torque comprises a sustained increase in torque. 
     
     
         4 . The tubular string of  claim 1 , in which the formation is further configured so that the change in torque comprises a fluctuation in torque. 
     
     
         5 . The tubular string of  claim 1 , in which the formation is further configured so that the change in torque comprises modulated data. 
     
     
         6 . The tubular string of  claim 5 , in which the data is selected from the group consisting of thread type, tubular size, turns to shoulder up, and optimal torque. 
     
     
         7 . The tubular string of  claim 1 , in which the formation comprises a deformation of the at least one of the first and second threads. 
     
     
         8 . The tubular string of  claim 1 , in which the formation comprises a deformable structure secured to the at least one of the first and second threads. 
     
     
         9 . The tubular string of  claim 1 , in which the formation comprises a series of protuberances on the at least one of the first and second threads, with a predetermined spacing between each adjacent pair of the protuberances. 
     
     
         10 . The tubular string of  claim 9 , in which the spacings are consistent between all adjacent pairs of the protuberances. 
     
     
         11 . The tubular string of  claim 9 , in which the spacings vary between the adjacent pairs of the protuberances. 
     
     
         12 . The tubular string of  claim 9 , in which the spacings comprise modulated data. 
     
     
         13 . The tubular string of  claim 1 , in which the formation comprises a series of sets of protuberances on the at least one of the first and second threads, and in which numbers of the protuberances in the sets vary. 
     
     
         14 . A method of making up a threaded connection between first and second tubular members, the method comprising:
 producing a structural formation on at least one of first and second threads respectively formed on the first and second tubular members;   engaging the first and second threads; and   applying torque to the threaded connection, thereby causing the first and second tubular members to shoulder up, in which the formation causes a change in the torque a predetermined number of turns prior to the shoulder up, and in which the first tubular member forms a pressure-tight seal directly with the second tubular member when the first thread is fully engaged with the second thread.   
     
     
         15 . The method of  claim 14 , in which in the applying, the formation causes a sustained increase in the torque. 
     
     
         16 . The method of  claim 14 , in which in the applying, the formation causes a fluctuation in torque. 
     
     
         17 . The method of  claim 14 , in which in the applying, the change in the torque comprises modulated data. 
     
     
         18 . The method of  claim 14 , in which in the producing, the formation comprises a deformation of the at least one of first and second threads. 
     
     
         19 . The method of  claim 14 , in which in the producing, the formation comprises a series of protuberances on the at least one of first and second threads, with a predetermined spacing between each adjacent pair of the protuberances. 
     
     
         20 . The method of  claim 14 , in which in the producing, the formation comprises a series of sets of protuberances on the at least one of first and second threads, and in which numbers of the protuberances in the sets vary.