Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
151 words
Interfacing apparatus for dual control of a subsea Christmas tree having a plurality of valve operators for controlling a plurality of tree-mounted operating valves, said apparatus comprising: a primary control module for normally operating said valve operators; a back-up control module for back-up operation of said valve operators; selection means for selectively connecting one of said primary control module and said back-up control module to said operating valves; a surface control unit for controlling the operation of said primary control module and said back-up control module and for controlling said selection means to determine which one of said primary and said back-up control modules is coupled to said operating valves; and means for mounting said selection means, said primary control module and said back-up control module adjacent said Christmas tree to facilitate replacement of said primary control module, said back-up control module and said selection means without accessing said Christmas tree.
Claim 2
Dependent Claim
151 words
Interfacing apparatus for dual control of a subsea Christmas tree having a plurality of valve operators for controlling a plurality of tree-mounted operating valves, said apparatus comprising: a primary control module for normally operating said valve operators; a back-up control module for back-up operation of said valve operators; selection means for selectively connecting one of said primary control module and said back-up control module to said operating valves; a surface control unit for controlling the operation of said primary control module and said back-up control module and for controlling said selection means to determine which one of said primary and said back-up control modules is coupled to said operating valves; and means for mounting said selection means, said primary control module and said back-up control module adjacent said Christmas tree to facilitate replacement of said primary control module, said back-up control module and said selection means without accessing said Christmas tree.
Claim 3
Dependent Claim
34 words
Interfacing apparatus as defined in claim 1 including a plurality of lines for carrying operating power to said valve operators, and means for connecting said lines between said valve operators and said selection means.
Claim 4
Dependent Claim
51 words
Interfacing apparatus as defined in claim 2 including a tree cap having a plurality of passageways therein, means for mounting said tree cap atop said Christmas tree and wherein at least a portion of said power carrying lines extend through said passageways in said tree cap and into said Christmas tree.
Claim 5
Dependent Claim
54 words
Interfacing apparatus as defined in claim 3 wherein said power carrying lines in said Christmas tree extend to the top portion of said Christmas tree for easy connection to a completion riser when said tree cap is removed, to enable said completion riser to control said valve operators when said tree cap is removed.
Claim 6
Dependent Claim
44 words
Interfacing apparatus as defined in claim 1 wherein said means for mounting said primary control module includes means for removable connecting said primary control module to said Christmas tree for removal and replacement while said back-up control module continues to operate said valve operators.
Claim 7
Dependent Claim
136 words
Interfacing apparatus for dual control of a subsea wellhead having a plurality of valve operators for controlling a wellhead valve system, said apparatus comprising: an electro-hydraulic control module for normally operating said valve operators; a hydraulic control module for back-up operation of said valve operators; means for selectively connecting one of said electrohydraulic control module and said hydraulic control module to said wellhead valve system; a surface control unit for controlling the operation of said electro-hydraulic and said hydraulic control modules and for selecting the control module which operates said valve operators; means for coupling control signals from said surface control unit to said valve operators when a tree cap is removed from said wellhead; and means for directing the operation of said hydraulic control module while said electro-hydraulic control module is being removed and replaced.
Claim 8
Dependent Claim
136 words
Interfacing apparatus for dual control of a subsea wellhead having a plurality of valve operators for controlling a wellhead valve system, said apparatus comprising: an electro-hydraulic control module for normally operating said valve operators; a hydraulic control module for back-up operation of said valve operators; means for selectively connecting one of said electrohydraulic control module and said hydraulic control module to said wellhead valve system; a surface control unit for controlling the operation of said electro-hydraulic and said hydraulic control modules and for selecting the control module which operates said valve operators; means for coupling control signals from said surface control unit to said valve operators when a tree cap is removed from said wellhead; and means for directing the operation of said hydraulic control module while said electro-hydraulic control module is being removed and replaced.
Claim 9
Dependent Claim
28 words
Interfacing apparatus as defined in claim 6 including means for connecting a production riser to control said valve operators when a tree cap is removed from said wellhead.
Claim 10
Dependent Claim
42 words
Interfacing apparatus as defined in claim 6 including means for mounting said electro-hydraulic control module, said hydraulic control module and said selective connecting means adjacent said wellhead to facilitate replacement of said modules and said selective connecting means without accessing said wellhead.
Claim 11
Dependent Claim
42 words
Interfacing apparatus as defined in claim 6 wherein said means for selectively connecting one of said control modules to said wellhead valve system includes at least one shuttle valve, and means for mounting said shuttle valve in one of said control modules.
Claim 12
Dependent Claim
143 words
Interfacing apparatus for dual control of a subsea Christmas tree having a plurality of valve operators for controlling a plurality of tree-mounted operating valves, said apparatus comprising: a primary control module for normally operating said valve operators; a back-up control module for back-up operation of said valve operators; selection means for selectively connecting one of said primary control module and said back-up module to said christmas tree; a tree cap having a plurality of hydraulic loops extending from the bottom of said tree cap up through said tree cap and returning to the bottom of the tree cap; means for connecting a first end of each of said hydraulic loops in said tree cap to said selection means; and means for connecting a second end of each of said hydraulic loops in said tree cap to a corresponding one to said valve operators.
Claim 13
Dependent Claim
143 words
Interfacing apparatus for dual control of a subsea Christmas tree having a plurality of valve operators for controlling a plurality of tree-mounted operating valves, said apparatus comprising: a primary control module for normally operating said valve operators; a back-up control module for back-up operation of said valve operators; selection means for selectively connecting one of said primary control module and said back-up module to said christmas tree; a tree cap having a plurality of hydraulic loops extending from the bottom of said tree cap up through said tree cap and returning to the bottom of the tree cap; means for connecting a first end of each of said hydraulic loops in said tree cap to said selection means; and means for connecting a second end of each of said hydraulic loops in said tree cap to a corresponding one to said valve operators.
Claim 14
Dependent Claim
45 words
Interfacing apparatus for dual control as defined in claim 10 including means for mounting said selection means, said primary control module and said back-up control module adjacent said Christmas tree to facilitate replacement of said modules and said selection means without accessing said Christmas tree.
Claim 15
Dependent Claim
32 words
Interfacing apparatus for dual control as defined in claim 11 including a surface control unit for controlling the operation of said primary control module, said back-up control module and said selection means.
Claim 16
Independent Claim
188 words
A method of interfacing a plurality of control systems between a surface-mounted control panel and a subsea wellhead having a plurality of valve operators in a Christmas tree at said wellhead, said method comprising the steps of: (1) mounting a primary control module near said Christmas tree, said primary control module having a primary control valve for each of said valve operators, (2) mounting a back-up control module near said Christmas tree, said back-up control module having a back-up control valve for each of said valve operators, (3) providing selection means for selectively coupling each of said primary control valves or each of said back-up control valves to a corresponding one of said valve operators in said Christmas tree, (4) mounting said selection means near said Christmas tree for easy replacement thereof without accessing said Christmas tree, (5) coupling selection signals between said control panel and said selection means to control the operation of said selection means, and (6) coupling control signal between said control panel and said primary control module or said back-up control module to operate the control valves which are coupled to said valve operators.
Claim 17
Independent Claim
188 words
A method of interfacing a plurality of control systems between a surface-mounted control panel and a subsea wellhead having a plurality of valve operators in a Christmas tree at said wellhead, said method comprising the steps of: (1) mounting a primary control module near said Christmas tree, said primary control module having a primary control valve for each of said valve operators, (2) mounting a back-up control module near said Christmas tree, said back-up control module having a back-up control valve for each of said valve operators, (3) providing selection means for selectively coupling each of said primary control valves or each of said back-up control valves to a corresponding one of said valve operators in said Christmas tree, (4) mounting said selection means near said Christmas tree for easy replacement thereof without accessing said Christmas tree, (5) coupling selection signals between said control panel and said selection means to control the operation of said selection means, and (6) coupling control signal between said control panel and said primary control module or said back-up control module to operate the control valves which are coupled to said valve operators.
Claim 18
Dependent Claim
38 words
A method of interfacing as defined in claim 13 including the additional steps of: mounting a tree cap atop said Christmas tree, and routing connecting lines through said tree cap between said valve operators and said selection means.
Claim 19
Dependent Claim
93 words
A method of interfacing as defined in claim 14 including the additional steps of: providing means for connecting control lines from a completion riser to the connecting lines at the top of said Christmas tree when said tree cap is removed and said completion riser is lowered on to the top of said Christmas tree, removing said tree cap from the top of said Christmas tree, connecting said completion riser to the top of said tree, and using said control lines in said completion riser to control the operation of said valve operators.
Claim 20
Independent Claim
243 words
A method of interfacing a plurality of control systems between a surface-mounted control panel and a subsea wellhead having a plurality of valve operators in a Christmas tree at said wellhead, said tree having a plurality of hydraulic supply lines connected to said tree, said method comprising the step of: (1) mounting a primary control module near said Christmas tree, said primary control module having a primary control valve for each of said valve operators, (2) mounting a back-up control module near said Christmas tree, said back-up control module having a back-up control valve for each of said valve operators, (3) providing selection means for selectively coupling each of said primary control valves or each of said back-up control valves to a corresponding one of said hydraulic supply lines in said Christmas tree, (4) mounting a tree cap atop said Christmas tree, (5) routing a plurality of hydraulic loops through said tree cap with each of said loops connected between one of said hydraulic supply lines and a corresponding one of said valve operators, (6) mounting said selection means near said Christmas tree for easy replacement thereof without accessing said Christmas tree, (7) coupling selection signals between said control panel and said selection means to control the operation of said selection means, and (8) coupling control signal between said control panel and said primary control module or said back-up control module to operate the control valves which are coupled to said valve operators.
Claim 21
Independent Claim
243 words
A method of interfacing a plurality of control systems between a surface-mounted control panel and a subsea wellhead having a plurality of valve operators in a Christmas tree at said wellhead, said tree having a plurality of hydraulic supply lines connected to said tree, said method comprising the step of: (1) mounting a primary control module near said Christmas tree, said primary control module having a primary control valve for each of said valve operators, (2) mounting a back-up control module near said Christmas tree, said back-up control module having a back-up control valve for each of said valve operators, (3) providing selection means for selectively coupling each of said primary control valves or each of said back-up control valves to a corresponding one of said hydraulic supply lines in said Christmas tree, (4) mounting a tree cap atop said Christmas tree, (5) routing a plurality of hydraulic loops through said tree cap with each of said loops connected between one of said hydraulic supply lines and a corresponding one of said valve operators, (6) mounting said selection means near said Christmas tree for easy replacement thereof without accessing said Christmas tree, (7) coupling selection signals between said control panel and said selection means to control the operation of said selection means, and (8) coupling control signal between said control panel and said primary control module or said back-up control module to operate the control valves which are coupled to said valve operators.