Tubing hanger for wellbore systems

Abstract

The present disclosure relates to a hanger assembly that has a cylindrical body having a top end, a bottom end, an outside surface, and a bore defined therethrough forming an inside surface. The hanger assembly further includes a lock ring having an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that is closest to the bottom end of the cylindrical body. The lock ring has an inside surface that contacts a portion of the outside surface of the cylindrical body. The lock ring also has an outside surface that has a diameter that is greatest at the lower end and smallest at the upper end. The lock ring is configured to fit within a load shoulder of a head to form a seal. The hanger assembly further includes a tapered piston seal ring disposed above the lock ring. The tapered piston seal ring has an annular shape that has an upper end that is closest to the top end of the cylindrical body and a lower end that partially fits into a space between the inside surface of the lock ring and the outside surface of the cylindrical body.

What is claimed is: 
     
         1 . A hanger assembly comprising:
 a cylindrical body comprising a top end, a bottom end, an outside surface, and a bore defined therethrough forming an inside surface;   a lock ring comprising:
 an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that is closest to the bottom end of the cylindrical body; 
 an inside surface that contacts a portion of the outside surface of the cylindrical body; and 
 an outside surface having a diameter that is greatest at the lower end and smallest at the upper end, 
   wherein the lock ring is configured to fit within a load shoulder of a head to form a seal;   a tapered piston seal ring disposed above the lock ring, the tapered piston seal ring comprising:
 an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that partially fits into a space between the inside surface of the lock ring and the outside surface of the cylindrical body. 
   
     
     
         2 . The hanger assembly of  claim 1 , further comprising a stationary seal having an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that seats against the upper end of the tapered piston seal ring at a first position. 
     
     
         3 . The hanger assembly of  claim 2 , wherein the tapered piston seal ring is configured to move downwardly such that the tapered piston seal ring is spaced from the stationary seal at a second position. 
     
     
         4 . The hanger assembly of  claim 1 , wherein the tubing head includes a first threaded port hole extending substantially horizontally through the tubing head that terminates above the tapered piston seal ring. 
     
     
         5 . The hanger assembly of  claim 4 , wherein the first threaded port hole is configured to receive hydraulic fluid. 
     
     
         6 . The hanger assembly of  claim 4 , wherein the tubing head includes a second threaded port hole extending substantially angularly through the tubing head that terminates at the load shoulder. 
     
     
         7 . The hanger assembly of  claim 6 , wherein the second port is configured to test the seal. 
     
     
         8 . A wellhead assembly comprising:
 a head comprising:
 a cylindrical body having a hollowed interior and comprising a top end, a bottom end, an outside surface, and an inside surface; and 
 an upper flange area located at the top end of the cylindrical body and comprising:
 a first threaded port hole running from the outside surface to the inside surface and configured to threadably connect to a threaded fitting, wherein the first threaded port hole is oriented at an about 90° angle with respect to the hollowed interior of the cylindrical body; 
 a second threaded port hole running from the outside surface to the inside surface and configured to threadably connect to a lockdown screw, wherein the second threaded port hole is oriented at an angle ranging from about 10° to about 80° with respect to the hollowed interior of the cylindrical body; and 
 a load shoulder located along the inside surface of the cylindrical body and comprising a diameter that is greater than a diameter of the inside surface of the cylindrical body; and 
 
   a hanger assembly comprising:
 a cylindrical body comprising a top end, a bottom end, an outside surface, and a bore defined therethrough forming an inside surface; and 
 a lock ring comprising:
 an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that is closest to the bottom end of the cylindrical body; 
 an inside surface that contacts a portion of the outside surface of the cylindrical body; and 
 an outside surface having a diameter that is greatest the lower end and smallest at the upper end, 
 
   wherein the lock ring is configured to fit within the load shoulder of the head to form a seal; and
 a tapered piston seal ring disposed at the upper end of the lock ring, the tapered piston seal ring comprising:
 an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that partially fits into a space between the inside surface of the lock ring and the outside surface of the cylindrical body. 
 
   
     
     
         9 . The wellhead assembly of  claim 8 , further comprising a stationary seal having an annular shape having an upper end that is closest to the top end of the cylindrical body and a lower end that seats against the upper end of the tapered piston seal ring at a first position. 
     
     
         10 . The wellhead assembly of  claim 9 , wherein the tapered piston seal ring is configured to move downwardly such that the tapered piston seal ring is spaced from the stationary seal at a second position. 
     
     
         11 . The wellhead assembly of  claim 8 , wherein the first threaded port hole is configured to receive hydraulic fluid. 
     
     
         12 . The wellhead assembly of  claim 8 , wherein the second threaded port hole is configured to test the seal. 
     
     
         13 . A method of sealing a hanger assembly to a head, comprising:
 providing a cylindrical body having a hollowed interior defining a load shoulder therein;   providing a hanger assembly having a cylindrical body, and a tapered piston seal ring and lock ring disposed below the tapered piston seal ring, the lock ring initially being spaced from the tapered piston seal ring;   landing the hanger assembly into the tubing head such that the hanger assembly rests on the load shoulder; and   actuating the tapered piston seal ring towards the lock ring to contact the lock ring and urge the lock ring to fit within the load shoulder to thereby seal the hanger assembly to the head.   
     
     
         14 . The method of  claim 13 , wherein the head is a tubing head, and further wherein the step of actuating comprises applying pressure through a port defined in the tubing head in a region immediately above the tapered piston seal ring. 
     
     
         15 . The method of  claim 14 , wherein the step of applying pressure comprises applying hydraulic fluid through the port defined in the tubing head. 
     
     
         16 . The method of  claim 15 , further comprising defining a second port through the tubing head, wherein the second port terminates at the load shoulder, wherein the second port is configured to test whether hydraulic fluid is exiting from the second port.