Method of installing and using offshore well development and production platforms

• US 4,492,270 A
• Filed: 04/06/1981
• Issued: 01/08/1985
• Est. Priority Date: 05/02/1980
• Status: Expired due to Fees

• Current Assignee: Global Marine Incorporated (Transocean Limited)
• Original Assignee: Global Marine Incorporated (Transocean Limited)
• Inventors: Horton, Edward E.
• Primary Examiner(s): CORBIN, DAVID
• Application Number:
  US06/251,112
• Time in Patent Office: 1,373 Days
• Field of Search: 405/196, 405/203, 405/204, 405/209, 405/227, 405/228, 175/9, 166/358
• US Class Current: 166/358
• CPC Class Codes: E02B 17/0004 Nodal points
• CPC Class Codes: E02B 17/021 with relative movement between supporting construction and platform
• CPC Class Codes: E02B 2017/006 with lattice style supporting legs

Abstract

A development and production facility for an offshore oil or gas field is constructed and drilling of wells is performed using a jack-up drilling platform in an improved manner. The facility is composed of a development well platform and a production platform, each of which is composed of a modular prefabricated unitary deck assembly of substantially turn-key completeness and of a prefabricated jacket or leg assembly to which the deck assembly is matable. Crane or derrick barges are used only to position the deck assemblies on the leg or jacket assemblies after the latter assemblies have been placed erect on and secured to the sea floor by use of the jack-up platform. The development well platform is constructed first so that drilling of development wells can be performed from the jack-up platform through the former platform concurrently with the placement and completion of the production platform.

Claims

1. A method for installing and using an offshore well development platform in water having a depth suitable for use of jack-up drilling platforms, the method comprising the steps of:

(a) providing a jack-up drilling platform having thereon;

(1) a drilling rig having an operative position in a drilling operations area outboard of an elevatable base of the jack-up platform; and

(2) a crane on the elevatable base adjacent the perimeter of the base and proximate the drilling rig operative position;

(b) positioning the jack-up platform at an offshore location with the base thereof elevated above the water surface so that the drilling operations area is located vertically over a submerged location on the sea floor at which at least one subsea oil or gas well is to be drilled;

(c) thereafter moving to the offshore location a prefabricated well protector jacket assembly having a length sufficient to extend from the submerged location to above the water surface thereabove, such length being insufficient to extend to the elevation of the drilling rig when the drilling rig is in its operative position;

(d) thereafter setting the well protector jacket assembly in an erect attitude on the sea floor over the submerged location;

(e) thereafter securing the sea jacket assembly to the sea floor over the submerged location by use at least in part, of the jack-up platform;

(f) moving to the site of the secured jacket assembly a prefabricated development wellhead deck assembly matable with the upper end of the secured jacket assembly;

(g) thereafter mating the wellhead deck assembly securely to the jacket assembly below the operative position of the drilling rig, thus to define independently of the jack-up platform a completed development wellhead platform above the water surface and below the operative position of the drilling rig;

(h) thereafter using the drilling rig in its operative position to drill and complete through the wellhead platform at least one well into the sea floor;

(i) at a desired time after performance of step (b) above, moving to the offshore location adjacent the jack-up platform a prefabricated production platform leg assembly having a length substantially equal to that of the well protector jacket assembly;

(j) thereafter, at a desired time after performance of step (e) above, setting the leg assembly in an erect attitude on the sea floor adjacent the secured jacket assembly;

(k) thereafter, securing the leg assembly to the sea floor by use, at least in part, of the jack-up platform;

(l) thereafter, moving to the site of the secured leg assembly a completed prefabricated production platform deck assembly matable with the upper end of the secured leg assembly; and

(m) thereafter, mating the production platform deck assembly securely to the production leg platform assembly to define a complete production platform.

2. The method according to claim 1 wherein the steps (i) through (m) are commenced after completion of at least step (c).

3. The method according to claim 1 wherein the performance of at least one of the steps (i) through (m) is commenced during at least part of the performance of step (h).

4. The method according to claim 1, including the further steps of:

(a) installing a bridge between the wellhead platform and the production platform; and

(b) connecting each completed well from the wellhead platform to the production platform via the bridge.

5. The method according to claim 4, including the further step, performed after completion at the wellhead platform of all wells to be drilled at the submerged location, of removing the jack-up platform from the offshore location.

6. The method according to claim 1 wherein the step of securing the jacket assembly to the sea floor comprises the further step of driving piles into the sea floor through the jacket assembly by use of a pile-driving tool supported by the jack-up platform crane.

7. The method according to claim 1 wherein the leg assembly is set on the sea floor at a location within the range of the jack-up platform crane, and the step of securing the leg assembly to the sea floor comprises the further step of driving piles into the sea floor through the leg assembly by use of a pile-driving tool supported by the crane.

8. The method according to claim 1, including the further steps of moving the development wellhead deck assembly to the site of the secured jacket assembly by use of a crane barge, and mating the wellhead deck assembly to the jacket assembly by use of the crane barge crane.

9. The method according to claim 1, including the further steps of moving the production platform deck assembly to the site of the secured leg assembly by use of a crane barge, and mating the production deck assembly to the leg assembly by use of the crane barge crane.