Plug installation system for deep water subsea wells

Abstract

A plug retrieval and installation tool is used with a subsea well having a production tree, a tubing hanger, a passage that extends vertically through the tubing hanger and the tree, and a plug located within a plug profile in the passage within the tubing hanger. The plug retrieval device has a housing and connector that is lowered on a lift line onto the upper end of the tree. An axially extendible stem in the housing is moved with hydraulic fluid controlled by an ROV into the production passage of the tubing hanger. An installation and retrieval member mounted to the stem engages the plug and pulls it upwardly in the passage while the stem is being moved upward, and pushes the plug downward to install the plug while the stem is being moved downward. The connector, drive mechanism and retrieval member are powered by an ROV.

1 - 18 . (canceled)  
     
     
         19 . An apparatus for retrieving a plug in a passage of a subsea wellhead assembly, comprising: 
 a housing adapted to be sealingly connected to an upper end of a subsea wellhead assembly;    an axially movable stem carried in the housing for movement between a retracted position and an extended position into the passage; and    a retrieving member mounted to the stem to engage the plug while in the extended position, and to retrieve the plug as the stem is moved to the retracted position.    
     
     
         20 . The apparatus according to  claim 19 , further comprising a drive mechanism for moving the stem between the engaged and retracted positions, the drive mechanism adapted to be powered by an ROV.  
     
     
         21 . A method for retrieving a plug in a passage of a subsea wellhead assembly, comprising: 
 (a) mounting an axially movable stem having a retrieval member thereon within a housing;    (b) lowering the housing on a lift line and sealingly connecting the housing to an upper end of a subsea wellhead assembly while the stem is in a retracted position;    (c) axially moving the stem downward into the passage and causing the retrieval member to engage the plug; and    (d) moving the stem upward along with the plug.    
     
     
         22 . The method according to  claim 21 , wherein step (b) further comprises providing a subsea tree that forms an upper portion of the subsea wellhead assembly, and wherein the housing sealingly connects to the subsea wellhead assembly by sealingly connecting to an upper end of the subsea tree.  
     
     
         23 . The method according to  claim 21 , wherein step (b) further comprises providing a subsea tree connected to a lower end of the housing, and wherein the housing and the subsea tree are lowered on the lift line, the housing being sealingly connected to the subsea wellhead assembly when the subsea tree sealingly connects to the subsea wellhead assembly.  
     
     
         24 . A method for retrieving a plug from a passage of a subsea wellhead assembly, comprising the steps of: 
 providing a retrieval device which comprises an extendable stem and a retrieval tool which is attached to the stem and removably connectable to the plug;    securing the retrieval device to the subsea wellhead assembly;    retrieving the plug from the passage using the retrieval device; and    removing the retrieval device from the subsea wellhead assembly with the plug connected to the retrieval device.    
     
     
         25 . The method according to  claim 24 , further comprising the step of sealing the retrieval device to the subsea wellhead assembly prior to the plug retrieving step; wherein the retrieval device forms a pressure-containing barrier between the passage and a surrounding environment.  
     
     
         26 . The method according to  claim 24 , wherein the retrieval device comprises an ROV operated subsea tool.  
     
     
         27 . The method according to  claim 24 , wherein the retrieval device is deployable from a surface facility on at least one of a cable and a drill string.  
     
     
         28 . The method according to  claim 24 , further comprising the step of retrieving the retrieval device to a surface facility with the plug connected to the retrieval device.  
     
     
         29 . The method according to  claim 28 , wherein the step of retrieving the retrieval device is performed with at least one of a cable and a drill string which is deployed from the surface facility.  
     
     
         30 . The method according to  claim 24 , wherein the plug retrieving step comprises the steps of extending the stem into engagement with the plug, connecting the retrieval tool to the plug and retracting the plug from the passage.  
     
     
         31 . A method for installing a plug in a passage of a subsea wellhead assembly, comprising: 
 providing an installation device which comprises an extendable stem and an installation tool which is attached to the stem and removably connectable to the plug;    connecting the plug to the installation tool;    securing the installation device to the subsea wellhead assembly; and    installing the plug in the passage using the installation device.    
     
     
         32 . The method according to  claim 31 , further comprising the step of sealing the installation device to the subsea wellhead assembly prior to the plug installing step; wherein the installation device forms a pressure-containing barrier between the passage and a surrounding environment.  
     
     
         33 . The method according to  claim 31 , wherein the installation device comprises an ROV operated subsea tool.  
     
     
         34 . The method according to  claim 31 , further comprising the step of lowering the installation device from a surface facility on at least one of a cable and a drill string.  
     
     
         35 . The method according to  claim 31 , further comprising the step of retrieving the installation device to a surface facility after the plug installing step.  
     
     
         36 . The method according to  claim 35 , wherein the step of retrieving the installation device is performed with at least one of a cable and a drill string which is deployed from the surface facility.  
     
     
         37 . The method according to  claim 35 , wherein the step of retrieving the installation device is performed with at least one of a cable and a drill string which is deployed from a facility located above the tree.  
     
     
         38 . The method according to  claim 31 , wherein the plug installing step comprises the steps of extending the stem to position the plug in the passage, securing the plug to the passage and disconnecting the plug from the installation tool.  
     
     
         39 . A method for installing a subsea wellhead assembly over a well bore, the subsea wellhead assembly comprising a wellhead which is installed at an upper end of the well bore; a tubing hanger which comprises at least one tubing hanger production passage, and a subsea tree which comprises at least one tree bore, the method comprising the steps of: 
 (a) installing the tubing hanger in the wellhead;    (b) installing a plug in the production passage;    (c) installing the subsea tree over the wellhead with the tree bore in alignment with the tubing hanger bore;    (d) providing a retrieval device which comprises an extendable stem and a retrieval tool which is attached to the stem and removably connectable to the plug;    (e) with the retrieval device secured to the subsea wellhead assembly above the subsea tree, retrieving the plug from the production passage through the tree bore using the retrieval device.    
     
     
         40 . The method according to  claim 39 , further comprising the step of sealing the retrieval device to the subsea wellhead assembly prior to the plug retrieving step; wherein the retrieval device forms a pressure-containing barrier between the tubing hanger bore and a surrounding environment.  
     
     
         41 . The method according to  claim 39 , wherein the retrieval device comprises an ROV operated subsea tool.  
     
     
         42 . The method according to  claim 39 , further comprising the step of lowering the subsea tree from a surface facility to the wellhead on at least one of a cable and a drill string;  
     
     
         43 . The method according to  claim 39 , further comprising the step of securing the retrieval device to the subsea tree after the subsea tree is installed over the wellhead.  
     
     
         44 . The method according to  claim 39 , further comprising the step of securing the retrieval device to the subsea tree prior to landing the subsea tree on the wellhead.  
     
     
         45 . The method according to  claim 44 , further comprising the step of lowering the retrieval device and the subsea tree from a surface facility to the wellhead on at least one of a cable and a drill string.  
     
     
         46 . The method according to  claim 39 , further comprising the step of removing the retrieval device from the subsea wellhead assembly with the plug connected to the retrieval device.  
     
     
         47 . The method according to  claim 46 , further comprising the step of retrieving the retrieval device to a surface facility with the plug connected to the retrieval device.  
     
     
         48 . The method according to  claim 47 , wherein the step of retrieving the retrieval device is performed with at least one of a cable and a drill string which is deployed from the surface facility.  
     
     
         49 . The method according to  claim 39 , wherein the wellhead is installed within an outer housing and the method further comprises the steps of: mounting a guide assembly to the outer housing; and orienting the tubing hanger relative to the guide assembly.  
     
     
         50 . The method according to  claim 49 , wherein the step of orienting the tubing hanger relative to the guide assembly comprises the steps of: landing a tubing hanger orientation tool on the wellhead; orienting the tubing hanger running tool relative to the guide assembly; and orienting the tubing hanger relative to the tubing hanger running tool.  
     
     
         51 . The method according to  claim 50 , further comprising the step of orienting the subsea tree relative to the guide assembly.  
     
     
         52 . The method according to  claim 39 , wherein the wellhead comprises a wellhead housing having a tubing spool positioned thereon, and in step (a) the tubing hanger is installed within one of the wellhead housing and the tubing spool.  
     
     
         53 . A method for retrieving a plug from a passage of a subsea wellhead assembly, comprising: 
 providing an ROV operated subsea tool (ROT) which comprises an extendable stem and a retrieval tool which is attached to the stem and removably connectable to the plug;    securing and sealing the ROT to the subsea completion system;    and retrieving the plug from the bore using the ROT.    
     
     
         54 . An apparatus for installing a subsea wellhead assembly comprising an outer housing which is positioned on the sea floor, an wellhead housing which is landed in the outer housing, at least one casing hanger which is connected to a corresponding casing string, a tubing hanger which is connected to a production tubing string and which includes at least one tubing hanger production passage, and a subsea tree which is installed over the wellhead housing and which includes at least one production bore that is aligned with the tubing hanger production passage, the apparatus comprising: 
 an ROV operated subsea tool (ROT) which comprises an elongated body; a bore which extends longitudinally through the body; an elongated stem which is positioned in the bore; a plug tool which is connected to an end of the stem; means for removably connecting the ROT to the subsea tree; and means for moving the stem through the bore to thereby move the plug tool through the production passage and into engagement with a plug in the production passage;    and at least one of a cable and a drill string which is connected to the ROT and by which the ROT and the subsea tree are lowered to the wellhead housing.    
     
     
         55 . A method for installing a subsea wellhead assembly comprising an outer housing which is positioned on the sea floor, a wellhead housing which is landed in the outer housing, at least one casing hanger which is connected to a corresponding casing string, a tubing hanger which is connected to a production tubing string and which includes at least one tubing hanger production passage, and a subsea tree which is installed over the wellhead housing and which includes at least one production bore, the method comprising the steps of: 
 (a) installing the outer housing on the sea floor;    (b) landing the wellhead housing in the outer housing;    (c) securing a blowout preventer (BOP) to the wellhead housing;    (d) landing the casing hanger in the wellhead housing through the BOP;    (e) connecting the tubing hanger to a tubing hanger running tool (THRT);    (f) landing the tubing hanger in the wellhead housing or the casing hanger through the BOP;    (g) installing a wireline plug in the production passage through the THRT;    (h) retrieving the THRT;    (i) retrieving the BOP;    (j) securing an ROV operated subsea tool (ROT) to the subsea tree;    (k) landing the subsea tree on the wellhead housing; and    (l) retrieving the wireline plug from the production passage using the ROT.    
     
     
         56 . The method according to  claim 55 , wherein: 
 in step (b) the wellhead housing further comprises a tubing spool positioned thereon, and    in step (f) the tubing hanger is landed through the BOP within one of the wellhead housing, the tubing spool, and the casing hanger.    
     
     
         57 . A method for installing a plug in a bore of a subsea wellhead assembly, the method comprising the steps of: 
 providing an ROV operated subsea tool (ROT), which comprises an extendable stem and an installation tool which is attached to the stem and removably connectable to the plug;    connecting the plug to the installation tool;    securing and sealing the ROT to the subsea completion system; and    installing the plug in the bore using the ROT.    
     
     
         58 . A method for installing a subsea wellhead assembly, the subsea wellhead assembly comprising a wellhead which is installed at an upper end of the well bore; a tubing hanger which comprises at least one tubing hanger production passage, and a subsea tree which comprises at least one tree bore, the method comprising the steps of: 
 (a) installing the tubing hanger in the wellhead;    (b) installing a plug in the production passage;    (c) installing the subsea tree over the wellhead with the tree bore in alignment with the production passage;    (d) providing an ROV operated subsea tool (ROT) which comprises an extendable stem and a retrieval tool which is attached to the stem and removably connectable to the plug;    (e) with the ROT secured to the subsea completion system above the subsea tree, retrieving the plug from the production passage through the tree bore with the ROT.    
     
     
         59 . The method according to  claim 58 , wherein the wellhead comprises a wellhead housing having a tubing spool positioned thereon, and in step (a) the tubing hanger is installed within one of the wellhead housing and the tubing spool.