WO2007029999A2

WO2007029999A2 - Containerised modular processing system

Info

Publication number: WO2007029999A2
Application number: PCT/MY2006/000010
Authority: WO
Inventors: David Appleford; Brian William Lane
Original assignee: Alpha Perisai Sdn. Bhd.; Alpha Thames Limited
Priority date: 2005-09-06
Filing date: 2006-09-06
Publication date: 2007-03-15
Also published as: CN101258302A; WO2007029999A3; MY139416A

Abstract

A system of exploiting a subsea hydrocarbon reserve, comprising a wet-trees process or a dry-trees process extracting hydrocarbon reserve from production wells (40) on the seabed, establishing a production riser (30) for transferring hydrocarbon reserve from the production wells (40) to a host platform and/or a floating production storage offloading unit characterized in that: a) the wet-tree process comprises of host platform (210) and/or floating production storage offloading unit (10) wherein said host platform (210) and/or floating production storage offloading unit (10) contain at least two modular processing units (20) , topside of which are connected in series located on the host platform (210) and/or the floating production storage offloading (FPSO) unit (10) ; b) the dry-tree process comprises of host platform (310) extracting hydrocarbon reserve from seabed production wells (40) via production riser (30) and said host platform (310) contains a plurality of dry-tree unit (320) extracts fluids from production wells (40) to process trains (60) located on the host platform (310) .

Description

CONTAINERISED MODULAR PROCESSING SYSTEM

FIELD OF INVENTION

The present invention relates to a system of extracting hydrocarbon from subsea production wells and more particularly to offshore, topside located, hydrocarbon processing systems and equipments for exploiting oil/gas fields including dry-trees and/or wet-trees process.

BACKGROUND OF INVENTION When developing offshore oil and gas fields, the extracted hydrocarbons are routed from the wells back to a surface host facility, which incorporates all of the required processing systems and equipments. The processing system is configured to cater for the predicted composition of the reservoir fluid and all of the changes that could possibly occur during the field life. Because the equipment is usually static, any access for servicing and maintenance must be considered, as extra space for possible additions, adding to the footprint of a host facility. All technicians, tools and equipments required for servicing, modifications and maintenance must be transported to the site in order to carry out the tasks.

During the servicing, modification or maintenance on the host facility, the flow of reservoir fluid conveyed by the pipeline will be interrupted which may effectively result in temporary shutting down one or more fields. Furthermore, in order to prepare a Floating Production Storage Offloading (FPSO) vessel for use on the next intended field, the vessel must be taken off-station and/or returned to base so that the old process system can be removed and scrapped before constructing a completely new system on deck. Again, the process system must be configured to cater for predicted composition of the reservoir fluid and all the changes that could possibly occur during the field life. The refitted FPSO vessel is then sailed to a new location before being commissioned for its duty on the new field.

As a consequence of this lengthy refitting process, many months of revenue is lost due to the non-production use of vessel operation. Overall, the host process system becomes excessively large and heavy. In addition, reconfiguration or replacement of the old process system to a new process system involves huge capital cost, expensive manpower and excessive time spent.

It is therefore an object of present invention to provide a system, which overcomes at least the above-mentioned disadvantages of the prior art. According to one aspect of the present invention there is provided an offshore, topside located, hydrocarbon processing system to be conveniently constructed in the form of a series of individual units under factory conditions at a secure and efficient onshore facility. The system can be used with dry-trees process topside located on the host platform and/or wet-trees process topside located on FPSO deck.

The process equipment is constructed in the form of compact modules that are easily handled, tested and integrated prior to being shipped to their offshore location. They can primarily be configured for immediate process requirements. Later, the manufacture of upgraded and reconfigured modules that satisfy the needs of changing field and reservoir conditions will be carried out under controlled factory conditions and, when needed, supplied on-site for rapid installation.

The result would be increased reliability, more efficient and less costly process units produced and installed without the need for skilled labour teams and the need for their tools and equipment to be transported and supported in an offshore environment. The space required for the process equipment is less than a conventional installation reducing the size and cost of the host facility. When the host is decommissioned, the process modules can be re-used elsewhere or re-cycled. Furthermore, an FPSO could be refurbished and reconfigured quickly without the need to take it off-station.

For a better understanding of the system and equipment, preferred embodiments of the present invention with the accompany drawings will be thereof describe in detailed description. SUMMARY OF INVENTION

The invention relates to a system of exploiting a subsea hydrocarbon reserve, comprising a wet-trees process or a dry-trees process extracting hydrocarbon reserve from production wells on the seabed, establishing a production riser for transferring hydrocarbon reserve from the production wells to a host platform and/or a floating production storage offloading unit.

The wet-tree process comprises of host platform and/or floating production storage offloading unit wherein the host platform and/or the floating production storage offloading unit contain at least two modular processing units, topside of which are connected in series located on the host platform and/or on the floating production storage offloading (FPSO) unit. A plurality of connecting means from production wells are connected to process trains located on the host platform and/or on the floating production storage offloading (FPSO) unit wherein the connecting means are supported by a buoyant means.

The dry-tree process comprises of host platform extracting hydrocarbon reserve from seabed production wells via production riser and the host platform contains a plurality of dry-tree unit extracts fluids from production wells to process trains located on the host platform. At least two modular processing units (20), topsides of which are connected in series located on the host platform (310) and, an offloading conduit conveying produced fluids from host platform to the floating storage offloading (FSO) unit wherein the offloading conduit is preferably supported by a buoyant means.

The dry-tree process includes a floating storage offloading (FSO) unit to receive separated component fluid from host platform to storage tanks of the floating storage offloading (FSO) unit. The modular processing units of wet-tree and dry tree process are connected in series, separate the hydrocarbon reserve into its different components. The modular processing units are mounted onto a system of multiple headers (maybe gas/oil/water) with multiple connection stations with common interfaces wherein it is of a "plug and socket" or "wellhead-type" connector and its cooperating parts is in form of a female part mounted a complementary male part over which the female part fits. Each series of modular processing unit performs a stepped process from crude separation into desired quality gas, oil and water wherein the oil is suitable for storage and water is cleaned suitable for jettison overboard.

The wet-tree process also can be a system integrated between both host platform and floating production storage offloading unit for separation process. The system integration of wet-tree process comprises of a production riser for transferring hydrocarbon reserve from the production wells to a host platform (210) and conveying to floating production storage offloading (FPSO) unit for further separation process. More particularly, the system integration of wet-tree process comprises of host platform wherein the host platform contains at least two modular processing units, topside of which are connected in series located on the host platform. A plurality of connecting means transferring hydrocarbon reserve from production wells to process trains located on the host platform.

The system integration of wet-tree process also comprises of floating production storage offloading unit wherein said floating production storage offloading unit contains at least two modular processing units, topside of which are connected in series located on the floating production storage offloading unit. A plurality of flow lines conveying hydrocarbon reserve or partial separated component fluid from host platform to process trains located on the floating production storage offloading unit wherein the flow lines are supported by a buoyant means. By this means, it is possible to feed a crude multi-phase well-produce into one end of the process train in the system and, after passing through the various modular processing units of the integrated system, process this into "dead" crude oil that is suitable for storage, gas that is "dry" enough for export and water that has been sufficiently cleaned for it to be jettisoned overboard.

BRIEF DESCRIPTION OF DRAWINGS

In the appended drawings: FIG. 1 shows a diagrammatic view of wet-tree hydrocarbon processing system whereby a series of processing units, topside located on FPSO according to the present invention.

FIG. 2 shows a top view of the system shown in FIG. 1. FIG. 3 shows a schematic diagram of the processing units configured on process header trains of the system according to the present invention.

FIG. 4 shows a diagrammatic view of wet-tree hydrocarbon processing system whereby a series of processing units, topside located on host platform according to the present invention. FIG. 5 shows a diagrammatic view of dry-tree hydrocarbon processing system whereby a plurality of dry tree units and a series of processing units, both topsides located on the host platform according to the present invention.

FIG. 6 shows a diagrammatic view of wet-tree hydrocarbon processing system of which the system is integrated between both host platform and floating production storage offloading unit for separation process according to the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Referring to FIG. 1 and FIG. 2 of accompanying drawings, the figures show a wet-tree hydrocarbon processing system (100) where a series of modular processing units (20) are located on the Floating Production Storage Offloading unit (FPSO) (10). A plurality of flow lines or production riser (30) is connected from production wells (40) to a docking unit (50) located along a process train (60) on the FPSO (10) deck. The flow lines or production riser (30) may include buoyant means (70) for supporting at least a part of weight of the flow lines or production riser (30) and such flow lines or production riser (30) are substantially flexible pipelines which allow fluid mixtures comprising water and oil/gas from production wells (40) conveyed to modular processing units (20).

The modular processing units (20) of the hydrocarbon processing system (100) are constructed under factory conditions at a secure and efficient onshore facility. The modular processing unit (20) is a retrievable substantially autonomous fluid separator module connected to docking unit (50) along the process trains (60) on the FPSO (10) deck. The modular processing unit (20) and the docking unit (50) is connected by a multibore fluid connector which is described in GB 2261271, where the connection is of a "plug and socket" or "wellhead-type" connector comprising cooperating parts in the form of a female part mounted a complementary male part over which the female part fits.

The modular processing unit (20) may be of the general type forming part of modular system for subsea use designed by Alpha Thames limited of Essex, United Kingdom, and referred to as AlphaPRIME. The modular processing units (20) can be of two-phase and/or three-phase separation module and a booster pump with single well flow measurement. The modular processing unit (20) for separation fluid mixtures is described in EP 1555387 and is incorporated in total herein. The modular processing can further accommodate sand removal as described in WO 03/041838 Al and possibly a gas compressor. In fact, due to the AlphaPRIME system-modular design approach, any new technology can be included into an existing system at a later date, when it becomes available, whilst production continues uninterrupted. The modular processing unit (20) can be progressively exchanged in the same way, in order to re-configure in response to changes of field characteristics or in order to incorporate the latest technology for optimum production.

Referring now to FIG. 3, figure shows the modular processing units (20a, 20b, 20c) mounted on the docking unit (50) along the process trains (60) on the FPSO (10) deck. Each process train (60) consists of three headers which are oil, gas and water. At intervals along each process train are a series of multibore fluid connectors (50) onto which are attached the retrievable factory-built modular processing units (20a, 20b, 20c). The modular processing units (2Oa', 20b', 20c') are the mirror image of the modular processing units (20a, 20b, 20c), both are in parallel arranged and symmetrical to each others. The said modular processing units (20a, 20b, 20c; 20a', 20b', 20c') are connected to the docking units (50) on the process trains (60) by multibore fluid connector as mentioned earlier. The arrangements of the modular processing units along the process trains (60) enable any one of the modular processing unit (20) to be removed for preventive maintenance whist other continues the processing operation without shutting down the system.

In FIG. 3, the docking units (50) of first pair modular processing unit (20a, 20a') received fluid mixtures from production wells (40) by well flow line or production riser (30). The docking unit (50) contains an interconnecting pipework and is capable of accompanying the modular processing units. The modular processing units (20a, 20a') each has for example, a two-phase separator chamber (21) for initial separation of fluids into oil and gas. The fluids are then diverted to the second pair of modular processing unit (20b, 20b') which contain three-phase separator (22) for further fluids separation into oil, gas and water. When needed, the fluids may further perform the separation process in separation chamber (23) of third pair modular processing unit (20c, 20c') obtaining quality gas (31), oil (32) suitable for storage, and water (33). The water has been sufficient cleaned and is jettisoned overboard.

Referring now to FIG. 4, figure shows another wet-tree hydrocarbon processing system (200) where a series of modular processing units (20) are located on a host platform (210). A plurality of flow lines or production riser (30) is connected from production wells (40) to docking unit (50) along process trains (60) on the host platform (210) deck. In the same way, fluids from production wells (40) pass through along the process train (60) and diverted to the modular processing units (20) to perform the separation process functions. Again, the first pair modular processing units may consist of two-phase separator chamber for initial separation of fluids into oil and gas. The fluids are then diverted to the second pair of modular processing unit which may contain three-phase separator for further fluids separation into oil, gas and water. The process separation is continuing to next modular processing unit until the required quality gas is obtained, oil suitable for storage and ready for collection, and water. The water has been sufficient cleaned and is jettisoned overboard.

Referring to FIG. 5, there is shown a dry-tree hydrocarbon processing system (300) where a series of modular processing units (20) are located on the host platform (310). A plurality of flow lines or production riser (30) is connected from production wells (40) to dry-tree unit (320), topside located, on the host platform (310) deck. The dry-tree unit (320) is a means for extracting fluids from production wells (40), which could be several hundred metres down under the host platform (310). The dry-tree unit then conveys the fluids from production wells (40) to process train (60) via flow lines or production riser (30). As the fluids from production wells (40) flow through along the process train (60), said fluids are diverted to the modular processing units (20) which perform the separation process that have been previously configured to do before returning them to the process train. The fluids continue further along the process trains (60) until they are diverted into the next modular processing units whereupon another separation process is carried out. The separation process is continuing until the required quality gas is obtained and the water is sufficiently cleaned for jettison overboard. The separated oil is then conveyed to a Floating Storage Offloading (FSO) vessel (330) by an offloading conduit (340) which includes a buoyant means (70) for supporting at least part of the weight of the offloading conduit (340).

Referring now to FIG. 6, there is shown another preferred embodiment of wet-tree hydrocarbon processing system (400) wherein said wet-tree hydrocarbon processing system (400) is a system integrated between both the processing system (200) on a host platform (210) and the hydrocarbon processing system (100) on the Floating Production Storage Offloading unit (FPSO) (10). The system comprising a series of modular processing units (20A) located on a host platform (210) where a plurality of flow lines or production riser (30) is connected from production wells (40) to the modular processing units (20A) which are preferably attached onto a series of multibore fluid connectors along process trains (60a) on the host platform (210) deck. Fluids from production wells (40) pass through along the process train (60a) and are diverted into the modular processing units (20A) to perform the separation process functions.

The wet-tree hydrocarbon processing system (400) further comprising a series of modular processing units (20B) located on a Floating Production Storage Offloading unit (FPSO) (10) where plurality flow lines (350) including a buoyant means (70) is connected from host platform (210) to the modular processing units (20B). The modular processing units (20B) are preferably attached onto a series of multibore fluid connectors along process trains (60b) on the FPSO (10) deck. The buoyant means (70) is used for supporting at least a part of weight of the flow lines (350) and are substantially flexible pipelines allowing fluid mixtures comprising water and oil/gas from host platform (210) conveyance to the modular processing units (20B) on the FPSO unit (10). The number of modular processing units will be governed by amount of fluid to be treated in given period of time, normally expressed in "Barrels per day", and the fluid composition, which determines the extent and complexity of processing required to transform a crude fluid into acceptable product. By this means, it is possible to feed a crude multi-phase well-produce into one end of the process train in the system and, after passing through the various modular processing units of the integrated system, process this into "dead" crude oil that is suitable for storage, gas that is "dry" enough for export and water that has been sufficiently cleaned for it to be jettisoned overboard.

The hydrocarbon processing systems and equipment is constructed in the form of compact modules that are easily handled, tested and integrated prior to being shipped to their offshore location. The wet-tree and dry tree hydrocarbon processing systems and equipment provide a "building block" method of development field in stage by stage. As each modular processing unit is an integrated autonomous unit, it enables total integration testing to be undertaken in factory before deployment, thus increasing reliability and reducing installation and commissioning time.

Claims

1. A system of exploiting a subsea hydrocarbon reserve, comprising a wet-trees process or a dry-trees process extracting hydrocarbon reserve from production wells (40) on the seabed, establishing a production riser (30) for transferring hydrocarbon reserve from the production wells (40) to a host platform and/or a floating production storage offloading unit characterized in that:

a) the wet-tree process comprises of host platform (210) and/or floating production storage offloading unit (10) wherein said host platform (210) and/or floating production storage offloading unit (10) contain at least two modular processing units (20), topside of which are connected in series located on the host platform (210) and/or on the floating production storage offloading (FPSO) unit (10); a plurality of connecting means (30) from production wells (40) connected to process trains (60) located on the host platform (210) and/or on the floating production storage offloading (FPSO) unit (10) wherein the connecting means (30) are supported by a buoyant means (70);

b) the dry-tree process comprises of host platform (310) extracting hydrocarbon reserve from seabed production wells (40) via production riser (30) and said host platform (310) contains a plurality of dry-tree unit (320) extracts fluids from production wells (40) to process trains (60) located on the host platform (310); at least two modular processing units (20), topsides of which are connected in series located on the host platform (310); an offloading conduit (340) conveying produced fluids from host platform (320) to the floating storage offloading (FSO) unit (330) wherein the offloading conduit (340) is preferably supported by a buoyant means (70);

wherein the modular processing units (20) connected in series separate the hydrocarbon reserve into its different components.

2. A system as claimed in claim 1, wherein the dry-tree process includes a floating storage offloading (FSO) unit (330) to receive separated component fluid from host platform (310) to storage tanks of the floating storage offloading (FSO) unit (330).

3. A system as claimed in claim 1, wherein the modular processing units (20) are mounted onto a system of multiple headers (either gas/oil/water) with multiple connection stations with common interfaces.

4. A system as claimed in claim 3, wherein the multiple connection station with common interface is of a "plug and socket" or "wellhead-type" connector.

5. A system as claimed in claim 1, wherein each series of modular processing unit (20) performs a stepped process from crude separation into desired quality gas, oil and water.

6. A system as claimed in claim 5, wherein the oil is suitable for storage and the water is suitable cleaned for jettison overboard.

7. A system of exploiting a subsea hydrocarbon reserve, comprising a wet-trees process extracting hydrocarbon reserve from production wells (40) on the seabed, establishing a production riser (30) for transferring hydrocarbon reserve from the production wells (40) to a host platform (210) and conveying to floating production storage offloading (FPSO) unit (10) for further separation process characterized in that: the host platform (210) contains at least two modular processing units (20A), topside of which are connected in series; a plurality of connecting means (30) to transfer hydrocarbon reserve from production wells (40) to process trains (60a) located on the host platform (210) and; the floating production storage offloading unit (10) contains at least two modular processing units (20B), topside of which are connected in series; a plurality of flow lines (350) to convey hydrocarbon reserve or partially separated component fluid from host platform (210) to process trains (60b) located on the floating production storage offloading unit (10) wherein the flow lines (350) are supported by a buoyant means (70);

wherein the modular processing units (2OA, 20B) connected in series separate the hydrocarbon reserve into required different components.

8. A system as claimed in claim 7, wherein the wet-tree process is a system integrated between both hydrocarbon processing system (100) present in the floating production storage offloading unit (10) and hydrocarbon processing system (200) present in the host platform (210).

9. A system as claimed in claim 7, wherein the modular processing units (2OA, 20B) are mounted onto a system of multiple headers (either gas/oil/water) with multiple connection stations with common interfaces.

10. A system as claimed in claim 9, wherein the multiple connection station with common interface is of a "plug and socket" or "wellhead-type" connector.

11. A system as claimed in claim 7, wherein each series of modular processing unit (2OA, 20B) performs a stepped process from crude separation into desired quality gas, oil and water.

12. A system as claimed in claim 11, wherein the oil is suitable for storage and the water is suitable cleaned for jettison overboard.