Single well development system

Abstract

A single well development system has a base structure ( 8 ) through which the well is drilled and completed by means of a wellhead ( 6 ). A retrievable Christmas tree module ( 10 ) containing a Christmas tree ( 12 ) connected to wellhead connector ( 14 ) is mounted on the base structure ( 8 ) by the wellhead connector ( 14 ) so as to receive well fluid from the wellhead. The module ( 10 ) contains two fluid processing separators ( 16 ) for processing fluid received from the well via the wellhead ( 6 ) and the Christmas tree ( 12 ). In a modification, additional modules are mounted on the base structure and each additional module has a fluid processing separator ( 16 ), and the Christmas tree module routes production fluid to the separators via the base structure ( 8 ).

1 . A single well development system comprising: 
 (i) a base structure ( 8 ) through which the well is drilled and completed by means of a wellhead ( 6 );    (ii) a retrievable christmas tree module ( 10 ) including a christmas tree ( 12 ) and connecting means ( 14 ) for connecting the christmas tree module to the wellhead ( 6 ) so as to receive well fluid therefrom; and    (iii) fluid processing means ( 15 ) for processing fluid received from the well via the wellhead ( 6 ) and christmas tree ( 12 ) and which is connected closely above the base structure ( 8 ):    
     
     
         2 . A system as claimed in  claim 1 , wherein the christmas tree module ( 10 ) is primarily supported by means of its connection to the wellhead ( 8 ).  
     
     
         3 . A system as claimed in  claim 1 , wherein the base structure ( 8 ) and/or the christmas tree module ( 10 ) include supplementary support means for the christmas tree module which is independent of the wellhead connecting means ( 14 ).  
     
     
         4 . A system as claimed in  claim 1  including at least one additional retrievable module ( 82 ).  
     
     
         5 . A system as claimed in  claim 1 , including a plurality of additional retrievable modules ( 82 ), each of which is connectable to the retrievable module ( 84 ) containing the christmas tree ( 12 ) via connection means ( 86 , 94 ) whereby the module connection means is configured to enable at least one additional retrievable module ( 82 ) to be isolated and removed from the base structure without affecting the connection between the christmas tree module ( 10 ) and any of the remaining modules of the system.  
     
     
         6 . A system as claimed in  claim 4 , wherein the fluid processing means ( 15 ) form part of the christmas tree module ( 10 ) and/or one or more of the additional retrievable modules ( 82 ).  
     
     
         7 . A system as claimed in  claim 6 , wherein each module ( 82 , 84 ) includes a module based part ( 88 , 96 ) of the module connection means ( 86 , 94 ) and the base structure includes a complementary base structure based part ( 90 , 98 ) of the module connecting means.  
     
     
         8 . A system as claimed in  claim 7 , wherein the base structure ( 92 ) includes fluid delivery means ( 100 ) for conveying fluid flowing from the christmas tree module ( 84 ) to the base structure ( 92 ) in separate and/or parallel flows to the at least one additional module ( 82 ).  
     
     
         9 . A system as claimed in  claim 8 , wherein the retrievable christmas tree module ( 10 ) includes a power and/or control pod ( 26 ).  
     
     
         10 . A system as claimed in  claim 4 , wherein at least one said additional retrievable module ( 82 ) includes a power and/or control pod ( 26 ).  
     
     
         11 . A system as claimed in  claim 10 , wherein a power and/or control pod ( 26 ) in one module ( 82 ) is connected to control components in another module ( 84 ).  
     
     
         12 . A system as claimed in  claim 4 , wherein the base structure includes electrical connection means ( 103 ) for conveying electrical power and/or control signals from one or more additional modules ( 82 ) to the wellhead tree module ( 84 ).  
     
     
         13 . A system as claimed in  claim 12 , wherein fluid processing means ( 15 ) in one or more of the modules comprises one or more separators ( 16 ).  
     
     
         14 . A system as claimed in  claim 13 , including at least one flow control valve ( 52 , 53 ) for controlling the flow through at least one said separator ( 16 ).  
     
     
         15 . A system as claimed in  claim 9 , wherein the at least one flow control valve ( 53 ) are adjusted under control of said power and/or control pod ( 26 ).  
     
     
         16 . A system as claimed in  claim 9 , including at least one electrical connector ( 18 ), the or each electrical connector comprising first and second interengageable portions ( 20 ,  22 ), the first interengageable portion ( 20 ) forming part of a said retrievable module ( 10 ) and the second interengageable portion ( 22 ) forming part of the base structure ( 8 ).  
     
     
         17 . A system as claimed in  claim 16 , wherein the first interengageable portion ( 22 ) of the electrical connector ( 18 ) is connected to the power and/or control pod ( 26 ) in the appropriate module.  
     
     
         18 . A system s claimed in  claim 16 , wherein the base structure second interengageable portion ( 22 ) of the electrical connector ( 18 ) is connected to an integrated service umbilical ( 24 ).  
     
     
         19 . A system as claimed in  claim 17 , wherein the connection means includes said electrical connector ( 18 ).  
     
     
         20 . A system as claimed in  claim 1 , including at least one fluid connector ( 28 ), the or each fluid connector comprising first and second engageable portions ( 30 , 32 ), the first portion ( 30 ) forming part of one said retrievable module ( 10 ) and the second portion ( 32 ) forming part of the base structure ( 8 ).  
     
     
         21 . A system as claimed in  claim 20 , wherein the base structure based second engageable portion ( 32 ) of the fluid connector ( 28 ) is connected to a flow line connection ( 34 , 36 ) for conveying fluid from the base structure ( 8 ) to one or more external flow lines ( 38 ).  
     
     
         22 . A system as claimed in  claim 20 , wherein the engageable portions ( 30 , 32 ) each include plural passageways for separate fluid flows and form part of the connecting means ( 14 ) for connecting the christmas tree ( 12 ) to the wellhead ( 6 ).  
     
     
         23 . A system as claimed in  claim 20 , wherein the connection means ( 86 , 94 ) includes said fluid connector for said at least one module.  
     
     
         24 . A system as claimed in  claim 1 , wherein at least one said module ( 10 , 82 ) includes at least part of the fluid processing means ( 15 ).  
     
     
         25 . A system as claimed in  claim 1 , wherein the base structure ( 8 ) comprise a drilling template for drilling a well.  
     
     
         26 . A system as claimed  claim 1 , wherein the base structure ( 8 ) includes means for guiding the at least one retrievable module onto the base structure.  
     
     
         27 . A system as claimed in  claim 1 , wherein the base structure ( 8 ) has means for supporting the at least one retrievable module.  
     
     
         28 . A method of exploiting the output from a single well, comprising the steps of: 
 (i) installing a base structure ( 8 );    (ii) drilling a well through the base structure ( 8 );    (iii) installing a casing string ( 2 ) in the drilled well;    (iv) terminating the casing string ( 2 ) with a wellhead ( 6 );    (v) connecting a retrievable christmas tree module ( 10 ) containing a christmas tree ( 12 ) to the wellhead ( 6 ) by means of connecting means ( 14 ) so as to receive well fluid therefrom;    (vi) providing fluid processing means ( 15 ) connected closely above the base structure ( 8 ); and    (vii) processing fluid received from the well via the wellhead ( 6 ) and christmas tree ( 12 ) with the processing means ( 15 ).