Monitoring torque in tubular goods

Abstract

The torque imposed on premium thread connections between tubular goods is monitored and plotted as a function of time rather than the number of turns. In this manner, the torque at which "shoulder", either by metal-to-metal sealing contact or otherwise, is achieved during make-up of the premium connection can be detected. Further, torque response of the connection after shoulder may be monitored. In addition, torque conditions during back out or disconnection may be monitored. Data obtained indicate if connections and seals are acceptable or not and often furnish evidence of the reason for certain types of unsatisfactory connections.

We claim: 
     
       1. A method of monitoring torque conditions during the make-up of a threaded premium tubular connection, wherein shoulder contact for metal-to-metal seal is formed in the threaded connection, comprising the steps of: (a) sensing the torque imposed on the connection during makeup;   (b) monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) establishing a supplemental torque level for an acceptable minimum torque differential imposed after .[.metal-to-metal seal is formed.]. .Iadd.shoulder contact.Iaddend.;   (d) displaying the sensed torque as a function of time.   
     
     
       2. The method of claim 1, further including the step of: forming an alarm indication when no threaded connection is obtained.   
     
     
       3. The method of claim .Iadd.1.Iaddend., further including the step of: forming an alarm indication when an unsatisfactory connection is obtained.   
     
     
       4. The method of claim 1, further including the step of: forming an indication of acceptability when a satisfactory threaded connection is obtained.   
     
     
       5. The method of claim 1, further including the step of: establishing an acceptable maximum torque level for the threaded connection.   
     
     
       6. The method of claim 5, further including the step of: forming an indication of whether or not the acceptable maximum torque level has been exceeded.   
     
     
       7. The method of claim 5, further including the steps of: (a) forming a sum signal representing the sum of the acceptable minimum torque differential and the torque level at which metal-to-metal seal is actually achieved;   (b) comparing the sum signal with the acceptable maximum torque level;   (c) interrupting torquing of the connection when the sum signal exceeds the acceptable maximum torque level.   
     
     
       8. The method of claim 1, further including the step of: establishing an acceptable minimum torque level for the threaded connection.   
     
     
       9. The method of claim 8, further including the step of: forming an indication of whether or not the acceptable minimum torque level has been exceeded.   
     
     
       10. The method of claim 1, further including the step of: forming an indication of whether or not the acceptable minimum torque differential is achieved.   
     
     
       11. A method of monitoring torque conditions during the make-up of a threaded premium tubular connection, wherein shoulder contact for metal-to-metal seal is formed in the threaded connection, comprising the steps of: (a) sensing the torque imposed on the connection during makeup;   (b) .[.a.]. monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) establishing a shoulder torque rate indicative of obtaining shoulder contact;   (d) displaying the sensed torque as a function of time.   
     
     
       12. The method of claim 11, wherein said step of monitoring torque conditions comprises the steps of: (a) monitoring the torque imposed on the connection during successive time intervals;   (b) forming an indication of change in torque between each successive time interval;   (c) comparing the indication of change in torque with .[.a specified.]. .Iadd.said .Iaddend.shoulder torque rate to detect whether or not .[.metal-to-metal.]. .Iadd.a shoulder condition .Iaddend.is achieved.   
     
     
       13. The method of claim 12, further including the step of: storing in a memory the monitored torque values for each successive time interval.   
     
     
       14. The method of claim 13, further including the step of: selectively erasing from the memory a predetermined percentage of the monitored torque values obtained prior to .[.metal-to-metal seal being achieved.]. .Iadd.shoulder contact.Iaddend..   
     
     
       15. The method of claim 14, further including the step of: ceasing said step of selectively erasing once .[.metal-to-metal seal.]. .Iadd.shoulder contact .Iaddend.is achieved.   
     
     
       16. An apparatus for monitoring torque conditions during the make-up of a threaded premium tubular connection, wherein shoulder contact for metal-to-metal seal is formed in the threaded connection, comprising: (a) means for sensing the torque imposed on the connection during makeup;   (b) means for monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) means establishing a supplemental torque level for an acceptable minimum torque differential imposed after .[.metal-to-metal seal is formed.]. .Iadd.shoulder contact.Iaddend.; and   (d) means for displaying the sensed torque as a function of time.   
     
     
       17. The apparatus of claim 16, further including: means for forming an alarm indication when no threaded connection is obtained.   
     
     
       18. The apparatus of claim 16, further including: means for forming an alarm indication when an unsatisfactory connection is obtained.   
     
     
       19. The apparatus of claim 16, further including: means for forming an indication of acceptability when a satisfactory threaded connection is obtained.   
     
     
       20. The apparatus of claim 16, further including: means for establishing an acceptable maximum torque level for the threaded connection.   
     
     
       21. The apparatus of claim 20, further including: means for forming an indication of whether or not the acceptable maximum torque level has been exceeded.   
     
     
       22. The apparatus of claim 20, further including: (a) means for forming a sum signal representing the sum of the acceptable minimum torque differential and the torque level at which .[.metal-to-metal seal.]. .Iadd.shoulder contact .Iaddend.is actually achieved;   (b) means for comparing the sum signal with the acceptable maximum torque level;   (c) means for interrupting torquing of the connection when the sum signal exceeds the acceptable maximum torque level.   
     
     
       23. The apparatus of claim 20, wherein the means for establishing a supplemental torque level includes: means for establishing a shoulder torque rate indicative of obtaining shoulder contact.   
     
     
       24. The apparatus of claim 23, wherein said means for monitoring torque conditions comprises: (a) means for monitoring the torque imposed on the connection during successive time intervals;   (b) means for forming an indication of change in torque between each successive time interval;   (c) means for comparing the indication of change in torque with .[.a specified.]. .Iadd.said .Iaddend.shoulder torque rate to detect whether or not .[.metal-to-metal seal.]. .Iadd.shoulder contact .Iaddend.is achieved.   
     
     
       25. The apparatus of claim 24, further including: memory means for storing the monitored torque values for each successive time interval.   
     
     
       26. The apparatus of claim 25, further including: means for selectively erasing from said memory means a predetermined percentage of the monitored torque values obtained prior to .[.metal-to-metal seal.]. .Iadd.shoulder contact .Iaddend.being achieved.   
     
     
       27. The apparatus of claim 16, further comprising: means for establishing an acceptable minimum torque level for the threaded connection.   
     
     
       28. The apparatus of claim 27, further including: means for forming an indicative of whether or not the acceptable minimum torque level has been exceeded.   
     
     
       29. The apparatus of claim 16, further including: means forming an indication of whether or not the acceptable minimum torque differential is achieved. .Iadd.   
     
     
       30.  A method of monitoring torque conditions during the make-up of a threaded tubular connection, wherein shoulder contact is formed in the threaded connection, comprising the steps of: (a) sensing the torque imposed on the connection during makeup;   (b) monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) establishing a supplemental torque level for an acceptable minimum torque differential imposed after shoulder contact; and   (d) displaying the torque sensed during make-up. .Iaddend. .Iadd.31. The method of claim 30, and including; comparing the monitored torque conditions with planned torque conditions from beginning to end of make-up to determine whether such a threaded connection would be acceptable for   
     
     
        service. .Iaddend. .Iadd.32.  The method of claim 31, and including; establishing an acceptable minimum torque level for the threaded connection, and forming an indication of whether or not the acceptable minimum torque level has been exceeded. .Iaddend. .Iadd.33. The method of claim 32, and including; establishing an acceptable maximum torque level for the threaded connection, and forming an indication of whether or not the acceptable maximum torque level has been exceeded. .Iaddend. .Iadd.34. The method of claim 30, and including: establishing an acceptable minimum torque level for the threaded connection, and forming an indication of whether or not the acceptable minimum torque level has been exceeded. .Iaddend. .Iadd.35. The method of claim 34, and including; establishing an acceptable maximum torque level for the threaded connection, and forming an indication of whether or not the acceptable maximum torque level has been exceeded. .Iaddend. .Iadd.36. A method for determining the torque required for shoulder contact when making up a threaded connection between tubular members which comprises operating pipe connection apparatus to cause thread engagement by relative rotation of the tubular members in a make-up direction,   sensing the amount of torque being applied by said apparatus during make-up,   identifying from the sensed torque changes in torque rate during make-up, and   signalling shoulder contact in response to a change in torque rate.   
     
     
        .Iaddend. .Iadd.37.  A method as defined by claim 36, and including: monitoring the torque conditions during the sensing of the torque to detect if a satisfactory threaded connection is obtained. .Iaddend. 
     
     
        .Iadd. 8.  A method as defined by claim 37, and including: adding the torque at shoulder contact to a predetermined minimum torque differential, and stopping the operation of the pipe connection apparatus when the sensed torque exceeds the sum of the torque at shoulder contact and the 
     
     
        predetermined minimum torque differential. .Iaddend. .Iadd.39.  A method as defined by claim 38, and including: stopping the operation of the pipe connection apparatus before the sensed torque reaches a predetermined 
     
     
        maximum torque. .Iaddend. .Iadd.40.  A method as defined by claim 36, and including: adding the torque at shoulder contact to a predetermined torque differential, and stopping the operation of the pipe connection apparatus when the sensed torque exceeds the sum of the torque at shoulder contact 
     
     
        and the predetermined torque differential. .Iaddend. .Iadd.41.  A method as defined by claim 40, and including: stopping the operation of the pipe connection apparatus before the sensed torque reaches a predetermined 
     
     
        maximum torque. .Iaddend. .Iadd.42.  A method of monitoring torque conditions during the make-up of a threaded tubular connection, wherein shoulder contact is formed in the threaded connection, comprising the steps of: (a) sensing the torque imposed on the connection during make-up;   (b) establishing an acceptable minimum torque level for the threaded connection at shoulder contact;   (c) monitoring the torque conditions during said step of sensing the torque to identify the torque at shoulder contact;   (d) displaying the torque sensed during make-up;   (e) and forming an indication of whether or not the acceptable minimum   
     
     
        torque level has been exceeded. .Iaddend. .Iadd.43.  The method of claim 42 and including: establishing an acceptable maximum torque level for the threaded connection, and forming an indication of whether or not the acceptable maximum torque level has been exceeded. .Iaddend. .Iadd.44. A method of monitoring torque conditions during the make-up of a threaded tubular connection, wherein shoulder contact is formed in the threaded connection, comprising the steps of: (a) sensing the torque imposed on the connection during makeup;   (b) establishing an acceptable minimum torque level for the threaded connection at shoulder contact;   (c) monitoring the torque conditions during said step of sensing the torque to identify the torque at shoulder contact;   (d) displaying the torque sensed during make-up;   (e) comparing the monitored torque conditions with planned torque conditions from beginning to end of make-up to determine whether such a threaded connection would be acceptable for service,   (f) and forming an indication of whether or not the acceptable minimum torque level has been exceeded. .Iaddend. .Iadd.45. The method of claim 44, and including: establishing an acceptable maximum torque level for the threaded connection, and forming an indication of whether or not the maximum torque level has been exceeded. .Iaddend. .Iadd.46. A method of monitoring torque conditions during the make-up of a threaded tubular connection, wherein shoulder contact is formed in the threaded connection, comprising the steps of:   (a) sensing the torque imposed on the connection during makeup;   (b) monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) establishing a shoulder torque rate indicative of obtaining shoulder contact; and   
     
     
       (d) displaying the torque sensed during make-up. .Iaddend. .Iadd.47.  The method of claim 46, wherein said step of monitoring torque conditions comprises the steps of: (a) monitoring the torque imposed on the connection during successive intervals;   (b) forming an indication of change in torque between each successive interval;   (c) comparing the indication of change in torque with said shoulder torque rate to detect whether or not a shoulder condition is achieved. .Iaddend.   
     
     
        .Iadd.48.  The method of claim 47, and including: storing in a memory the monitored torque values for each successive interval. .Iaddend. .Iadd.49. The method of claim 48, further including the step of:   selectively erasing from the memory a predetermined percentage of the monitored torque values obtained prior to shoulder contact. .Iaddend. .Iadd.50. The method of claim 49, further including the step of:   ceasing said step of selectively erasing once shoulder contact is achieved. .Iaddend. .Iadd.51. An apparatus for monitoring torque conditions during the make-up of a threaded premium tubular connection, wherein shoulder contact is formed in the threaded connection, comprising:   (a) means for sensing the torque imposed on the connection during makeup;   (b) means for monitoring the torque conditions during said step of sensing the torque to detect if a satisfactory threaded connection is obtained;   (c) means establishing a supplemental torque level for an acceptable minimum torque differential imposed after shoulder contact; and   
     
     
       (d) means for displaying the sensed torque. .Iaddend. .Iadd.52.  The apparatus of claim 51, further including: means for forming an alarm indication when no threaded connection is obtained. .Iaddend. .Iadd.53. The apparatus of claim 51, further including:   means of forming an alarm indication when an unsatisfactory connection is obtained. .Iaddend. .Iadd.54. The apparatus of claim 51, further including:   means for forming an indication of acceptability when satisfactory threaded   
     
     
        connection is obtained. .Iaddend. .Iadd.55.  The apparatus of claim 51, further including: means for establishing an acceptable maximum torque level for the threaded connection. .Iaddend. .Iadd.56. The apparatus of claim 55, further including:   means for forming an indication of whether or not the acceptable maximum torque level has been exceeded. .Iaddend. .Iadd.57. The apparatus of claim 55, further including:   (a) means for forming a sum signal representing the sum of the acceptable minimum torque differential and the torque level at which shoulder contact is actually achieved;   (b) means for comparing the sum signal with the acceptable maximum torque level; and   (c) means for interrupting torquing of the connection when the sum signal   
     
     
        exceeds the acceptable maximum torque level. .Iaddend. .Iadd.58.  The apparatus of claim 55, wherein the means for establishing a supplemental torque level includes: means for establishing a shoulder torque rate indicative of obtaining shoulder contact. .Iaddend. .Iadd.59. The apparatus of claim 58, wherein said means for monitoring torque conditions comprises:   (a) means for monitoring the torque imposed on the connection during successive intervals;   (b) means for forming an indication of change in torque between each successive interval;   (c) means for comparing the indication of change in torque with said shoulder torque rate to detect whether or not shoulder contact is achieved. .Iaddend. .Iadd.60. The apparatus of claim 59, further including:   memory means for storing the monitored torque values for each successive   
     
     
        interval. .Iaddend. .Iadd.61.  The apparatus of claim 51, further including: means for establishing an acceptable minimum torque level for the threaded connection. .Iaddend. .Iadd.62. The apparatus of claim 61, further including:   means for forming an indication of whether or not the acceptable minimum torque level has been exceeded. .Iaddend. .Iadd.63. A method for making up a shouldered threaded connection between tubular members which comprises,   operating pipe connection apparatus to cause thread engagement by relative rotation of the tubular members in a make-up direction,   sensing the amount of torque being applied by said apparatus during make-up,   identifying from the sensed torque changes in torque rate during make-up,   identifying from changes in torque rate the point at which shoulder contact is achieved,   continuing to make-up the connection until the sensed torque exceeds the total of the torque at shoulder contact and a predetermined minimum torque differential, and   stopping the make-up of the connection when the sensed torque exceeds the sum of the torque at shoulder contact and the predetermined minimum torque differential but is less than a predetermined maximum acceptable torque. .Iaddend.