Back pressure valve with latching engagement system and method

Abstract

This disclosure presents a latch back pressure valve for use with a wellhead assembly. The latch back pressure valve includes a body and at least one seal extending circumferentially around the body. A plurality of extendable latches are supported by the body and configured to engage with corresponding locking grooves. A poppet is configured to be displaced to open a passageway through the body. A hold-down ring is configured to engage a miming tool such that rotation of the miming tool causes the plurality of extendable latches to an extended position.

What is claimed is: 
     
         1 . A back pressure valve, comprising:
 a body;   at least one seal extending circumferentially around the body;   a plurality of extendable latches supported by the body;   a poppet valve configured to be displaced to open a passageway through the body; and   a hold-down ring configured to engage a running tool such that rotation of the running tool and the hold-down ring extends the plurality of extendable latches from a retracted position to an extended position.   
     
     
         2 . The back pressure valve of  claim 1  wherein the at least one seal is a self-energizing interference seal. 
     
     
         3 . The back pressure valve of  claim 1  wherein the at least one seal comprises an upper seal and a lower seal disposed vertically spaced apart from the upper seal. 
     
     
         4 . The back pressure valve of  claim 1  wherein the hold-down ring comprises a slot configured to engage a pin of the running tool. 
     
     
         5 . The back pressure valve of  claim 1  wherein the plurality of extendable latches comprises at least four extendable latches circumferentially spaced apart about the body. 
     
     
         6 . The back pressure valve of  claim 1  wherein each of the plurality of latches comprises a first peak separated from a second peak by a valley. 
     
     
         7 . The back pressure valve of  claim 1  wherein the hold-down ring is in threaded engagement with the body. 
     
     
         8 . The back pressure valve of  claim 1  further comprising at least one anti-rotation pin. 
     
     
         9 . The back pressure valve of  claim 1  further comprising a threaded interior surface configured to engage with a pressure release tool. 
     
     
         10 . A wellhead assembly, comprising:
 a primary seal comprising a landing shoulder and at least one locking groove, the at least one locking groove formed on an inner surface of the primary seal; and   a back pressure valve configured to land on the landing shoulder, the latch back pressure valve comprising a hold-down ring, at least one seal extending circumferentially around a body, and a plurality of latches, wherein rotation of the hold-down ring extends each latch of the plurality of latches to be received by the at least one locking groove.   
     
     
         11 . The wellhead assembly of  claim 10  wherein the primary seal further comprises an input conduit and a gauge conduit, the input conduit terminating at an inner seal surface of the primary seal. 
     
     
         12 . The wellhead assembly of  claim 11  wherein the at least one seal of the latch back pressure valve comprises an upper seal and a lower seal, and wherein the input conduit terminates axially between the upper seal and the lower seal. 
     
     
         13 . The wellhead assembly of  claim 10  wherein the at least one locking groove comprises an upper angled surface configured to contact upper angled surfaces of each of the plurality of latches. 
     
     
         14 . The wellhead assembly of  claim 10  further comprising a casing hanger supporting a casing, the primary seal forming a seal with the casing hanger. 
     
     
         15 . The wellhead assembly of  claim 10  wherein the hold-down ring is in threaded engagement with the body of the latch back pressure valve. 
     
     
         16 . A method of sealing a wellhead, comprising:
 securing a primary seal within a wellhead, the primary seal including at least one locking groove configured to receive a latch of a back pressure valve;   securing a wear bushing to the primary seal, the wear bushing covering the at least one locking groove;   landing the latch back pressure valve on a load shoulder of the primary seal; and   rotating a portion of the latch back pressure valve to extend a plurality of latches, the extended latches being received by the at least one locking groove.   
     
     
         17 . The method of  claim 16  further comprising fluidly coupling an external pressure source to a conduit formed in the primary seal and pressurizing the conduit with the external pressure source. 
     
     
         18 . The method of  claim 16  further comprising using a gauge to detect a pressure drop in the conduit. 
     
     
         19 . The method of  claim 16  further comprising coupling a running tool to the portion of the latch back pressure valve, and wherein rotating the running tool extends the plurality of latches. 
     
     
         20 . The method of  claim 19  further comprising coupling a pressure release tool to the latch back pressure valve and rotating the pressure release tool to displace an internal seal in the latch back pressure valve and allow a wellbore back pressure to be received through the latch back pressure valve, the pressure release tool being separate from the running tool. 
     
     
         21 . The method of  claim 16  further comprising removing the wear bushing from the primary seal before landing the latch back pressure valve. 
     
     
         22 . The method of  claim 16  wherein rotating the portion of the latch back pressure valve comprises rotating a hold-down ring in threaded engagement with a body of the latch back pressure valve, a downward motion of the hold-down ring directing radial extension of the plurality of latches.