Unmanned or remotely operated platform

Abstract

An unmanned wellhead platform (1) (UWP) comprising a jacket (10) designed and adapted to be supported on the seabed and projecting above the sea level is shown. The unmanned wellhead platform (1) includes a topside installed on top of the jacket (10). The topside is designed as a standardized base concept tailored for repetitive future topside constructions (3). Each topside construction (3) is adapted to the number of wells to be developed. The topside construction (3) is made up by a number of different but standardized sections (4). Each standardized section (4) is dedicated for a particular and predetermined purpose and location in the topside construction (3).

Claims

1. An unmanned wellhead platform comprising: a jacket configured to be supported on the seabed and projecting above the sea level; a topside structure installed on top of the jacket and comprising at least two decks; wherein the topside structure is expandable via the addition of one or more standardized sections, the topside structure being adapted to a number of wells to be developed, the topside structure comprising a plurality of different standardized sections, each of the plurality of different standardized sections being dedicated for a particular and predetermined purpose and location; and wherein the plurality of different standardized sections adopt different sizes and configurations and are grouped in sets of sections having equal dimensions.

2. The unmanned wellhead platform according to claim 1, wherein some of the plurality of different standardized sections have at least one defined well slot, each well slot having received its respective and unique number from 1 (one) and up, wherein each numbered well slot repeatedly receives the same location in the topside construction each time a base topside construction is constructed.

3. The unmanned wellhead platform according to claim 1, wherein at least one of said plurality of different standardized sections is adapted to receive and mount various components associated with a dedicated well.

4. The unmanned wellhead platform according to claim 1, wherein the plurality of different standardized sections are grouped in standardized structural sections and standardized equipment sections.

5. The unmanned wellhead platform according to claim 1, wherein each of the plurality of different standardized sections spans over at least two decks.

6. The unmanned wellhead platform according to claim 5, wherein each of the plurality of different standardized sections spans over three decks, the three decks being a cellar deck, a middle deck and a weather deck.

7. The unmanned wellhead platform according to claim 1, wherein the topside structure comprises a plurality of dedicated well slots selected from eight, twelve, and sixteen dedicated well slots, each well slot being adapted to receive required components for one respective well.

8. The unmanned wellhead platform according to claim 1, wherein the topside construction is rotated in the horizontal plane approximately 45 degrees relative to corner legs of the jacket.

9. The unmanned wellhead platform according to claim 1, wherein the jacket is an equilateral jacket adjusted for sea depth, metocean data, soil condition, and strength required for the location of the unmanned platform.

Description

SHORT DESCRIPTION OF THE DRAWINGS

(1) While the various aspects of the present invention have been described in general terms above, a more detailed and non-limiting example of embodiments will be described in the following with reference to the drawings, in which:

(2) FIG. 1 shows a schematic perspective view an unmanned wellhead platform according to the present invention,

(3) FIG. 2 shows a schematic top view of a first embodiment of the unmanned wellhead platform shown in FIG. 1, the platform having 8 well slots,

(4) FIG. 3 shows a schematic top view a second embodiment of the unmanned wellhead platform shown in FIG. 1, the platform having 12 well slots,

(5) FIG. 4 shows a schematic top view a third embodiment of the unmanned wellhead platform shown in FIG. 1, the platform having 16 well slots,

(6) FIG. 5 shows a schematic view from above the first embodiment shown in FIG. 2, and with the top deck (weather deck and xmas deck) removed,

(7) FIG. 6 shows a schematic view from above the second embodiment shown in FIG. 3, and with the top deck (weather deck and xmas deck) removed,

(8) FIG. 7 shows a schematic view from above the third embodiment shown in FIG. 4, and with the top deck (weather deck and xmas deck) removed,

(9) FIG. 8a shows a principal view an exemplary layout of various pipes and components onboard said platform, view from the side

(10) FIG. 8b shows a principal view of an exemplary layout of various pipes and components onboard said platform, viewed from above,

(11) FIG. 9 shows in schematic view a typical field layout.

DETAILED DESCRIPTION OF THE INVENTION

(12) Reference is made to FIG. 1 showing an unmanned wellhead platform 1. The platform, or more precisely a topside 3, is installed on top of a jacket 10 (FIG. 2). The jacket 10 is designed with legs 9 (FIG. 2) and adapted to be supported on the seabed. The jacket 10 is secured to the seabed by suction buckets (anchors) or piles. The jacket 10 is normally a truss structure projecting above the sea level to support the topside frame construction 3 on top of the jacket structure. A number of risers 2 extend from the seabed up to the topside 3. The topside frame construction 3 further includes a swing crane 5 having reach all over the top deck floor 6.

(13) Basically, the topside frame construction 3 is designed as a frame construction (also numbered 3), normally made up by several decks, here three decks are shown. The lowest deck is a cellar deck D.sub.1, next is a XMT deck D.sub.2 and weather deck D.sub.3 on top. The top area can easily be expanded or diminished.

(14) The topside frame construction 3 is designed as a standardized base concept. This means that the concept is prepared for repetitive future use. However, the topside frame construction 3 needs to be adapted to each project depending on the number of wells to be operated and the site where it is to be located. The topside frame construction 3 could be adjusted according to the number of wells that are needed. This could be any number from 1-16. Further the number of decks are adjusted. The deck area and the height between the decks are defined accordingly.

(15) The topside frame construction 3 is divided into a number of sections 4. Each section 4 is standardized in respect of size and intended use. However, even if many sections 4 are equal, many sections 4 are different also. Hence, they are grouped into particular sizes, but each size is standardized. Each section size is dedicated for a particular and predetermined purpose and location in the topside frame construction 3. Example of purpose and location are shown in FIG. 5-7, and in the description below referring to the figures.

(16) FIG. 2-4 shows three different embodiments of D3, namely D3, D3, D3 of the weather deck of the topside frame construction 3.

(17) As more clearly shown in FIG. 2, some of the standardized sections 4 of the topside construction 3 has defined well slots 1.sub.S to 8.sub.S. Each well slot has received its unique number. For future eight well slots topside frame constructions 3 to be built, each numbered well slot 1.sub.S-8.sub.S repeatedly receives exact the same location in the topside frame construction 3. Thus, such base topside frame constructions 3 are named as standardized.

(18) The number of standardized sections 4 can be grouped in sets of equal sections, though the sections may adopt different sizes and configurations in the various sets. Two coarsely divided groups of sections can be standardized structural sections and standardized equipment sections, as an example. In FIG. 2 they are numbered 4 and 4 respectively.

(19) At least one of the standardized sections 4 is adapted to receive and mount various components associated with a dedicated well.

(20) In the embodiment shown in FIG. 2, the topside construction 3 is rotated in the horizontal plane approximately 45 degrees relative to corner legs 9 of the jacket structure 10. This provides benefits with regard to accessibility and reach for a jack-up rig (not shown) to be located adjacent to the unmanned wellhead platform 1. The legs of the jack-up rig are able to straddle over the corner leg 9 of the jacket 10 and in this way, being able to arrive as close as possible to the unmanned wellhead platform topside construction 3 and thus the well area. A material handling platform 11 is also shown. This platform 11 is located at a desired height above sea level. The platform 11 could be, either of the fixed design located at a higher level, or a temporary platform intended for location at a lower level closer to the sea.

(21) As mentioned, the topside construction 3 is sectioned where the most important parameter for the total size of the topside construction 3 is the number of well slots 1.sub.S to 16.sub.S. The well slots are dedicated to be either producers, injectors, flexibles (both producer and injector) and redundant.

(22) Referring to FIGS. 2, 3 and 4, the unmanned wellhead platform typically has from two to sixteen well slots. As mentioned, the well slots numbered 1.sub.S to 16.sub.S are given a fixed location according to numerical value. For example, a ten slot unmanned wellhead platform will receive slot locations as shown in FIG. 3 up to slot number 10.

(23) Each well slot has a set of components topside in order to be able to produce or inject the well. This is typically wellhead, XMT (Christmas tree), flow control valves, flow meters and isolation valves.

(24) Each well slot is typically 2.52.5 meters. The wellhead and XMT are installed within this area.

(25) The topside construction 3 is sectioned with predetermined location and design of the respective sections 4.

(26) As mentioned, the sections 4 can have different sizes, dependent of the number of well slots and location in the topside construction 3.

(27) As an example, shown in FIG. 2, the topside construction 3 can be based on a 20 m20 m deck floor 6 (FIG. 1) and in three heights (decks). This one has 2-8 wells. However, the number of wells can be expanded, for example as shown in FIG. 3 with up to four more wells. Then you need to expand the area with a row of sections 20 m5.5 m as shown in the bottom of FIG. 3. If you expand with four more wells, as shown in FIG. 4, you need to expand the area with another row of sections 20 m5.5 m as shown on top of FIG. 4.

(28) Typical values for sections having four different sizes, dependent of the number of well slots, can be:

(29) TABLE-US-00001 2-4 wells 14 14 11 m (not shown) 4-8 wells 20 20 11 m (FIG. 2) 9-12 wells 20 25 (including cantilever in south) (FIG. 3) 13-16 wells 20 30 (including cantilever in north) (FIG. 4)

(30) The equipment has standardized layout (for example the FIG. 6 injection system), is sectioned and located in fixed locations for the respective topside sizes and scaled in accordance with the number of wells. Typical sections/areas are: Well area, shown in the figure as producers and injectors Production area Injection (WAG) (Water and Gas) area Gas lift area Hydraulics Electro, Instrument, control, telecom (EICT) (XMT deck, not shown on drawing) Material handling area Area for pigging operation equipment

(31) As an example, a water and gas/injection well on a 10 slots unmanned wellhead platform then will have: Layout of flow control, measurement and isolation valve as shown in FIGS. 8a and 8b Flow control, measurement and isolation valve as shown in FIGS. 8a and 8b will be connected to a manifold in water and gas area as shown in FIG. 6.

(32) As mentioned, the construction typically has three deck levels, cellar deck D.sub.1, xmas tree deck D.sub.2 and weather deck D.sub.3.

(33) On cellar deck D.sub.1 (FIGS. 5, 6 and 7) the well heads (producers and injectors) are installed together with equipment for flow regulation, flow measurements, isolation valves, manifolds, gas lift etc in the different sections or area as shown in the figures.

(34) FIG. 5-7 discloses three different embodiments D1, D1, D1 of the cellar deck of the topside frame structure 3. The embodiments corresponding to the weather deck D3, D3, D3 as disclosed above in FIG. 2-4.

(35) On xmas tree deck D.sub.2, the xmas tree is placed together with equipment for power supply (electro), control systems, inlet of umbilical from the mother platform, injection systems.

(36) The weather deck D.sub.3 has hatches 12 for access to the various wells. The weather deck D3 shields the well area and operates as base for connection to the wells for conducting well intervention. On the weather deck D.sub.3 there are room for a pig skidder. The pig skidder can easily be connected to a temporary piping spool connected to the risers 2 down at the cellar deck D.sub.1. The pig skidder is arranged to launch or receive a plug device that is forced through the pipeline system for cleaning purpose after the installation and before the start production/operation of the platform.

(37) As an Example, one global layout is shown in FIG. 9. What shown is: A Jack-up Rig (JUR) approaching from windward side; minimize the jack up rig (JUR) exposure of potential gas leakage during drilling and well operations. Service operation vessel (SOV) approach from leeward side; minimize risk for SOV interference with the unmanned wellhead platform in case of e.g. Dynamic positioning (DP) failure Flowline and umbilical routing to avoid conflict with jack-up rig footprint Four possible SOV headings for simultaneous material handling from SOV and Walk to work (W2W) connected to the unmanned wellhead platform. The walk to work is a bridge landing system for use between a fixed installation and a floating vessel for personnel transfer. Dropped object protection above flowlines and umbilical close to the unmanned wellhead platform might be required

(38) The hook-up philosophy is as follows. It is kept at a minimum, only risers and J-tubes are required. The topside is designed for single lift offshore. This means that all components are ready installed and tested. Only hook-up spools are required to complete the connection between topside and jacket. Hook-up spools are fabricated onshore and shipped to the topside. Possible adaptions are made offshore.

(39) The control system is preferably in an EICT container. The choice was to collect electrical and instrument cabinets within the EICT container. The size of the container can vary, it is determined by the equipment it is to contain. Primary location for such container will be in direction south on the Xmas tree deck D2, since this will provide a good air direction on Norwegian offshore sector, i.e. prevailing wind is often toward north-east. All equipment within the container are Ex secured.

(40) The external material handling takes place either to/from Jack-Up Rig (JUR) or to/from Service Operation Vessel (SOV). Toward jack up rig (JUR) the external material handling is performed by crane located on jack up rig (JUR) and towards dedicated landing areas on the unmanned wellhead platform. Toward unmanned wellhead platform also called SOS (subsea on a stick), the external material handling takes place with crane located on SOV toward dedicated load platform on. unmanned wellhead platform

(41) Internal material handling takes place in vertical shafts typically 2 m3 m extending from weather deck to cellar deck.