Subsea wellhead system

Claim 2

A subsea wellhead system comprising: a wellhead template assembly including: a wellhead means adapted to be associated with a well hole and including a removable wellhead unitary portion, and a production control means spaced and separated from said wellhead means and including a removable production control unitary portion; means operably interconnecting said wellhead and production control means; each of said wellhead and production control unitary portions being adapted to be isolated from the wellhead system; whereby a selected one of said removable portions is recoverable for maintenance above surface without disturbing the remainder of the wellhead template assembly.

Claim 3

A wellhead system as stated in claim 1 wherein said wellhead template assembly includes a plurality of sets of such wellhead and production control means; and a common manifold means connected to each of the production control means.

Claim 4

A wellhead system as stated in claim 1 wherein said production control unitary portions includes valve means for controlling and regulating flow of fluids into and out of the well hole.

Claim 5

A subsea wellhead system as stated in claim 1 including means operably interconnecting said production control means with a remote sea surface location for operating said production control means at said remote location.

Claim 6

A wellhead system as stated in claim 1 wherein said wellhead means includes control valves for said production flow line operable into fail-safe closed position and in closed position permitting removal of said production control means.

Claim 7

In a subsea wellhead system for a plurality of relatively closely spaced well holes in an ocean floor, the combination of: a wellhead template assembly at said ocean floor and including template frame means; a wellhead means associated with each well hole; a production control means supported on said frame means adjacent to and separate from said wellhead means; a manifold means connecting each of said production control means; each of said wellhead means including a removable recoverable unit comprising valve means for well fluids; each of said production control means including a removable unit including flow control means for said well fluids, and control means for said valve means in said wellhead means and said production control means; and connecting lines for conducting well fluids between said wellhead means and production control means.

Claim 8

In a subsea wellhead system for a plurality of relatively closely spaced well holes in an ocean floor, the combination of: a wellhead template assembly at said ocean floor and including template frame means; a wellhead means associated with each well hole; a production control means supported on said frame means adjacent to and separate from said wellhead means; a manifold means connecting each of said production control means; each of said wellhead means including a removable recoverable unit comprising valve means for well fluids; each of said production control means including a removable unit including flow control means for said well fluids, and control means for said valve means in said wellhead means and said production control means; and connecting lines for conducting well fluids between said wellhead means and production control means.

Claim 9

In a wellhead system including a plurality of well holes in a preselected arrangement, the provision of: a wellhead template frame construction including a plurality of conductor guide means arranged in the same pattern as said well holes; means on each conductor guide means for connecting a wellhead unit thereto; a production control unit carried by said template frame construction adjacent to each conductor guide means and adapted to be connected to an associated wellhead unit; manifold means carried by the template frame construction and connected with each production control unit for flow of production oil and gas; each of said production control units including separable portions, one portion including valve means for isolating said production control unit from said manifold means; and means releasably interconnecting said other production control unit portion to said one portion for recovery of said other portion for maintenance thereof.

Claim 10

In a wellhead system including a plurality of well holes in a preselected arrangement, the provision of: a wellhead template frame construction including a plurality of conductor guide means arranged in the same pattern as said well holes; means on each conductor guide means for connecting a wellhead unit thereto; a production control unit carried by said template frame construction adjacent to each conductor guide means and adapted to be connected to an associated wellhead unit; manifold means carried by the template frame construction and connected with each production control unit for flow of production oil and gas; each of said production control units including separable portions, one portion including valve means for isolating said production control unit from said manifold means; and means releasably interconnecting said other production control unit portion to said one portion for recovery of said other portion for maintenance thereof.

Claim 11

A wellhead system as stated in claim 7 including: a wellhead unit connected to each of said conductor guide means and associated well hole; and means releasably interconnecting each of said associated wellhead units and production control units for flow of production oil and gas therebetween and for control of such flow.

Claim 12

In a method of establishing a wellhead system for a subsea well installation having a plurality of well holes arranged in a preselected, compact pattern, the steps of: placing a prefabricated wellhead template construction having conductor guide means arranged in said preselected pattern in registered operative relation with said well holes, said wellhead template construction including separable removable production control units in adjacent relation to said conductor guide means; connecting a preassembled wellhead unit to each well hole and conductor guide means therefor; releasably interconnecting each of said wellhead units and adjacent production control units with production oil and gas flow lines; and releasably interconnecting each of said wellhead units and adjacent production control unit with control means; whereby each of said production control units may be independently isolated from its associated wellhead unit and wellhead template frame construction for recovery thereof.

Claim 13

In a method of establishing a wellhead system for a subsea well installation having a plurality of well holes arranged in a preselected, compact pattern, the steps of: placing a prefabricated wellhead template construction having conductor guide means arranged in said preselected pattern in registered operative relation with said well holes, said wellhead template construction including separable removable production control units in adjacent relation to said conductor guide means; connecting a preassembled wellhead unit to each well hole and conductor guide means therefor; releasably interconnecting each of said wellhead units and adjacent production control units with production oil and gas flow lines; and releasably interconnecting each of said wellhead units and adjacent production control unit with control means; whereby each of said production control units may be independently isolated from its associated wellhead unit and wellhead template frame construction for recovery thereof.

Claim 14

In a method of establishing and maintaining a wellhead system for a subsea well installation which includes a plurality of well hole locations in a selected pattern, the steps of: providing a wellhead template construction having conductor guide tubes arranged in a pattern corresponding to said selected well hole pattern and carrying production control means including separable movable production control units; lowering and releasably connecting a wellhead means including a separable wellhead unit to said conductor guide tubes; releasably interconnecting said wellhead means and said production control means for control of gas and oil flow lines and control means therefor and for isolation of one of said units from the other unit; and removing a selected one of said units for maintenance thereof.

Claim 15

In a method of establishing and maintaining a wellhead system for a subsea well installation which includes a plurality of well hole locations in a selected pattern, the steps of: providing a wellhead template construction having conductor guide tubes arranged in a pattern corresponding to said selected well hole pattern and carrying production control means including separable movable production control units; lowering and releasably connecting a wellhead means including a separable wellhead unit to said conductor guide tubes; releasably interconnecting said wellhead means and said production control means for control of gas and oil flow lines and control means therefor and for isolation of one of said units from the other unit; and removing a selected one of said units for maintenance thereof.

Claim 16

In a method as stated in claim 10 including the steps of: manifolding the gas and oil flow lines of a plurality of production control means whereby one of said units selected for maintenance may be independently isolated for removal and recovery thereof while said other units retain their operable condition

Claim 17

In a wellhead system including a plurality of well holes normally adapted to be simultaneously operated, the combination of: a wellhead template frame structure; wellhead means including a separate wellhead unitary portion on said frame structure and adapted to be associated with a well hole; a production control means including a separable production control unitary portion spaced from said wellhead means; means operably interconnecting gas and oil flow lines of said wellhead means and production control means; control means for said wellhead means and production control means and including means for isolating at least one of said separable unitary portions whereby said one separable portion is recoverable and removable for above-surface maintenance.

Claim 18

In a wellhead system including a plurality of well holes normally adapted to be simultaneously operated, the combination of: a wellhead template frame structure; wellhead means including a separate wellhead unitary portion on said frame structure and adapted to be associated with a well hole; a production control means including a separable production control unitary portion spaced from said wellhead means; means operably interconnecting gas and oil flow lines of said wellhead means and production control means; control means for said wellhead means and production control means and including means for isolating at least one of said separable unitary portions whereby said one separable portion is recoverable and removable for above-surface maintenance.

Claim 19

In a wellhead system as stated in claim 12 including: a plurality of wellhead means and a plurality of production control means associated therewith; and common manifold means for said plurality of production control means.

Claim 20

In a wellhead system as stated in claim 13 including track means spaced from said production control means and extending from one production control means to the adjacent production control means; means on said wellhead means and production control means for releasing said wellhead unitary portion and production control unitary portion respectively, said release means on said wellhead means and production control means being accessible from said track means and adapted for separate independent release of a unitary portion with respect to the other unitary portion.

Claim 21

A subsea wellhead system comprising: a wellhead template system comprising: a plurality of wellhead means each adapted to be Associated with a well hole, and a plurality of production control means spaced and separated from said wellhead means; means operably interconnecting said wellhead and production control means; each production control means including means for selectively directing production fluid into a common production manifold or test flow line; each of said wellhead and production control means including a removable unit adapted to be isolated from the wellhead system, whereby a selected one of said removable units is recoverable for maintenance above surface without disturbing the remainder of the wellhead assembly.

Claim 22

A subsea wellhead system comprising: a wellhead template system comprising: a plurality of wellhead means each adapted to be Associated with a well hole, and a plurality of production control means spaced and separated from said wellhead means; means operably interconnecting said wellhead and production control means; each production control means including means for selectively directing production fluid into a common production manifold or test flow line; each of said wellhead and production control means including a removable unit adapted to be isolated from the wellhead system, whereby a selected one of said removable units is recoverable for maintenance above surface without disturbing the remainder of the wellhead assembly.