Patent Grant
8826839
Not applicable.
1. Field of the Invention
The invention relates generally to floating production and offloading units (FPSOs). More particularly, the invention relates to methods and systems for installing pre-integrated processing modules on an FPSO.
2. Background of the Technology
Floating Production Storage and Offloading units (FPSOs) are commonly used in offshore oil and gas operations to temporarily store and then offload produced oil. An FPSO vessel is designed to receive crude oil produced from a nearby platform or subsea template, process the crude oil (e.g., separate water from the crude oil), and store the processed oil until it can be offloaded to a tanker or transported through a pipeline. FPSOs are particularly suited in frontier offshore regions where there is no pipeline infrastructure in place for transporting produced oil to shore. For example, FPSOs are often employed to store produced oil until it can be offloaded to a tanker for transport to another location.
Typically, FPSOs are ship-shaped floating vessels that provide a relatively large oil storage volume, various production modules, personnel accommodations, and equipment. In general, FPSOs may be constructed from scratch as a new vessel or by transforming the hull of an old oil tanker. In either case, the construction of an FPSO requires the installation of a number of modules such as modules for power generation, fluid separation, utilities, water treatment and gas compression. In some cases, the number of modules installed is relatively large (e.g., upwards of 15-18 modules).
Conventionally, the modules are constructed at different sites, often by separate entities, loaded onto the deck of the FPSO with cranes, and then assembled, integrated and commissioned on top of the FPSO. Due to the weight of each module, and the load capacity of cranes, the modules are typically loaded onto the FPSO one-by-one. Consequently, the time and cost to finalize an FPSO project is constrained by the operational challenges of loading the modules onto the FPSO, assembling and integrating the modules once loaded onto the FPSO, and then commissioning modules aboard the FPSO. In addition, for refurbished FPSOs, conversion of the old oil tanker's hull may require unanticipated repairs and/or reinforcements that may further constrain loading, assembly, integration, and commissioning of the modules, thereby further increasing costs and delay delivery of the completed FPSO.
Accordingly, there remains a need in the art for improved methods and systems for constructing FPSOs, and in particular, for loading and installing modules onto an FPSO. Such methods and systems would be particularly well-received if they offered the potential to reduce the time, and associated costs, to load, install, and integrate the modules.
These and other needs in the art are addressed in one embodiment by a method for constructing an FPSO. In an embodiment, the method comprises (a) assembling and integrating a plurality of modules to form a module assembly for installation on the FPSO. In addition, the method comprises (b) supporting the module assembly with one or more ballast adjustable pontoons. Further, the method comprises (c) positioning the module assembly over a deck of a vessel after (a) and (b). Still further the method comprises (d) de-ballasting the vessel and/or ballasting the one or more pontoons to load the module assembly onto the deck of the vessel after (c).
These and other needs in the art are addressed in another embodiment by a system for installing a pre-assembled and pre-integrated module assembly on a vessel disposed in a body of water to form an FPSO. In an embodiment, the system comprises a floating vessel configured to be ballasted and de-ballasted. In addition, the system comprises a pair of horizontally spaced parallel pontoons defining an open bay configured to receive the floating vessel. Each pontoon is ballast adjustable. Further, the system comprises a support system coupled to the pontoons and configured to support the module assembly over the open bay.
These and other needs in the art are addressed in another embodiment by a method for constructing an FPSO. In an embodiment, the method comprises (a) assembling and integrating a plurality of modules on-shore to form a module assembly for installation on the FPSO. In addition, the method comprises (b) coupling the module assembly to a support system moveably disposed on a plurality of rails after (a). Further, the method comprises (c) moving the module assembly along the rails to a position over a deck of a vessel. Still further, the method comprises (d) transferring the module assembly from the support system to the deck of the vessel after (c).
These and other needs in the art are addressed in another embodiment by a system for installing a pre-assembled and pre-integrated module assembly on a vessel disposed in a body of water to form an FPSO. In an embodiment, the system comprises an integration area including a pair of first rails. In addition, the system comprises a plurality of second rails extending from the integration area over the surface of water. Each second rail is aligned with one of the first rails. Further, the system comprises a carriage moveably coupled to each first rail and each second rail. Still further, the system comprises a support system coupled to the carriages and configured to support the module assembly.
Embodiments described herein comprise a combination of features and advantages intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical advantages of the invention in order that the detailed description of the invention that follows may be better understood. The various characteristics described above, as well as other features, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
The following discussion is directed to various exemplary embodiments. However, one skilled in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.
Certain terms are used throughout the following description and claims to refer to particular features or components. As one skilled in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.
In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection, or through an indirect connection via other devices, components, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a central axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the central axis. For instance, an axial distance refers to a distance measured along or parallel to the central axis, and a radial distance means a distance measured perpendicular to the central axis.
Embodiments described herein disclose multiple deck-mating systems and methods for installing a plurality of pre-integrated modules onto the deck of a floating hull to faun an FPSO. Such deck-mating systems and methods enable the modules to be built and integrated while the FPSO is under construction or transformation, thereby reducing the number of integrations performed aboard an FPSO after the modules are loaded thereon. In particular, multiple modules are built and pre-integrated simultaneous with (i.e., in parallel with) the fabrication or transformation of the FPSO hull. When the FPSO hull is ready to receive the modules, a significant portion of the module integration has already been performed and the pre-integrated modules may be installed at the same time, thereby offering the potential to reduce the total time expended for module integration and enable timely delivery of the completed FPSO.
Referring now to
Module assembly 11 comprises a plurality of modules typically installed on an FPSO. As is known in the art, modules installed on an FPSO include, without limitation, modules for power generation, fluid separation, utilities, water treatment, and gas compression. In embodiments described herein, a plurality of such modules are built, assembled, and integrated to form assembly 11 prior to being loaded and installed on vessel 90. In particular, module assembly 11 is assembled and integrated on-shore, and then transported to vessel 90 and installed thereon to form an FPSO.
First barge 20 is a conventional buoyant flat barge sized and configured to support module assembly 11 above the surface of the water 15. Thus, first barge 20 has a buoyancy sufficient to support the entire weight of module assembly 11 above the surface of water 15.
Referring now to
Each wall 44 comprises a plurality of vertical, ballast adjustable buoyant columns 50 arranged side-by-side in an axial row. Each column 50 has a central or longitudinal axis 55, a first or upper end 50a at top 42, and a second or lower end 50b coupled to one lateral side 46 of base 43. In addition, each column 50 has a length L50 measured parallel to axis 55 between ends 50a, b, and a diameter D50 measured perpendicular to axis 55. In general, the length L50 and the diameter D50 of each column 50 may be tailored to the anticipated loads, FPSO construction site and associated water depth. For most cases, the diameter D50 of each column 50 is between 5 and 10 m. In this embodiment, each column 50 is identical.
Spaced walls 44 and associated columns 50 define a passage or bay 47 extending between ends 40a, b of second barge 40. Bay 47 has a length L47 measured parallel to axis 45 between ends 40a, b, and a width W47 measured perpendicular to axis 45 between walls 44. As will be described in more detail below, bay 47 is sized to receive first barge 20, module assembly 11, and vessel 90, and second barge 40 supports the weight of module assembly 11. Thus, the actual width W47 of bay 47 will depend on a variety of factors including, without limitation, the width of first barge 20, the width of module assembly 11, and the beam (i.e., width) of vessel 90; and the actual length L47 of bay 47 will depend on variety of factors including, without limitation, the number of buoyant columns 50 in wall 44 required to support the weight of module assembly 11. For most applications, the width W47 ranges from 35 to 60 m and the length L50 ranges from 60 to 100 m. It should be appreciated that the length L47 and the width W47 of bay 47 can be adjusted by increasing the dimensions of base 43 (i.e., length and width), adding more columns 50 to each wall 44, or combinations thereof.
Referring now to
End caps 52 close off ends 50a, b of column 50, thereby preventing fluid flow through ends 50a, b into chambers 60, 69, respectively. Bulkheads 53 close off the remaining ends of chambers 60, 62, 68, 69, thereby preventing fluid communication between adjacent chambers 60, 62, 68, 69. Thus, each chamber 60, 62, 68, 69 is isolated from the other chambers 60, 62, 68, 69 in column 50.
Chambers 68, 69 are filled with a gas 16 and sealed from the surrounding environment (e.g., water 15), and thus, provide buoyancy to column 50. Accordingly, chambers 68, 69 may also be referred to as buoyant chambers. In this embodiment, gas 16 is air, and thus, may also be referred to as air 16. Chamber 60 is at least partially filled with fixed ballast 17 (e.g., iron ore, magnetite or ferrite slurry, etc.) to facilitate the vertical orientation of column 50. During FPSO construction operations, the fixed ballast 17 in chamber 60 is generally permanent (i.e., remains in place). During FPSO construction operations, variable ballast 18 in chamber 62 can be controllably varied (i.e., increased or decreased), as desired, to vary the buoyancy of column 50 and second barge 40. In this embodiment, surrounding sea water 15 is used for variable ballast 18.
Although column 50 includes four chambers 60, 62, 68, 69 in this embodiment, in general, each column (e.g., each column 50) may include any suitable number of chambers. Preferably, at least one chamber is a ballast adjustable chamber and one chamber is an empty buoyant chamber (i.e., filled with air). Although end caps 52 and bulkheads 53 are described as providing fluid tight seals at the ends of chambers 60, 62, 68, 69, it should be appreciated that one or more end caps 52 and/or bulkheads 53 may include a closeable and sealable access port (e.g., man hole cover) that allows controlled access to one or more chambers 60, 62, 68, 69 for maintenance, repair, and/or service.
Columns 50 provide buoyancy to second barge 40, and thus, may be referred to as pontoons. In addition, columns 50 are ballast adjustable to control and vary the draft of barge 40. In this embodiment, a ballast control system 70 and a port 71 enable adjustment of the volume of variable ballast 18 (e.g., seawater 15) in chamber 62. More specifically, port 71 is an opening or hole in tubular 51 axially disposed between the upper and lower ends 50a, b. It should be appreciated that flow through port 71 is not controlled by a valve or other flow control device. Thus, port 71 permits the free flow of water 15, 18 into and out of chamber 62.
Referring still to
In this embodiment, open end 72b is disposed proximal the upper end of chamber 62 and port 71 is positioned proximal the lower end of chamber 62. This positioning of open end 72b enables air 16 to be exhausted from chamber 62 when column 50 is in a generally vertical, upright position. In particular, since buoyancy air 16 is less dense than water 15, 18, any air 16 in chamber 62 will naturally rise to the upper portion of chamber 62 above any water 15,18 in chamber 62 when column 50 is upright. Accordingly, positioning end 72b at or proximal the upper end of chamber 62 allows direct access to any air 16 therein. Further, since water 15,18 in chamber 62 will be disposed below any air 16 therein, positioning port 71 proximal the lower end of chamber 62 allows ingress and egress of water 15, 18 while limiting and/or preventing the loss of any air 16 through port 71. In general, air 16 will only exit chamber 62 through port 71 when chamber 62 is filled with air 16 from the upper end of chamber 62 to port 71. Positioning of port 71 proximal the lower end of chamber 62 also enables a sufficient volume of air 16 to be pumped into chamber 62. In particular, as the volume of air 16 in chamber 62 is increased, the interface 110 between water 15, 18 and the air 16 will move downward within chamber 62 as the increased volume of air 16 in chamber 62 displaces water 15, 18 in chamber 62, which is allowed to exit chamber through port 71. However, once the interface 110 of water 15, 18 and the air 16 reaches port 71, the volume of air 16 in chamber 62 cannot be increased further as any additional air 16 will simply exit chamber 62 through port 71. Thus, the closer port 71 to the lower end of chamber 62, the greater the volume of air 16 that can be pumped into chamber 62, and the further port 71 from the lower end of chamber 62, the lesser the volume of air 16 that can be pumped into chamber 62. Thus, the axial position of port 71 along chamber 62 is preferably selected to enable the maximum desired buoyancy for chamber 62.
In this embodiment, conduit 72 extends through tubular 51. However, in general, the conduit (e.g., conduit 72) and the port (e.g., port 71) may extend through other portions of the column (e.g., column 50). For example, the conduit may extend axially through the column (e.g., through cap 71 at upper end 50a) in route to the ballast adjustable chamber (e.g., chamber 62). Any passages (e.g., ports, etc.) extending through a bulkhead or cap are preferably completely sealed.
Furthermore, ballast control system 70 is preferably configured and controlled such that each column 50 is ballasted or de-ballasted simultaneously and contains about the same volume of air 16 and water 15, 18 at any given time to ensure second barge 40 remains stable with base 43 oriented substantially horizontal. This is particularly important when second barge 40 is supporting a load, such as module assembly 11.
Referring still to
Although ballast adjustable chamber 62 and fixed ballast chamber 60 are distinct and separate chambers in column 50 in this embodiment, in other embodiments, a separate fixed ballast chamber (e.g., chamber 60) may not be included. In such embodiments, the fixed ballast (e.g., fixed ballast 17) may simply be disposed in the lower end of the ballast adjustable chamber (e.g., chamber 62). The ballast control system (e.g., system 70) may be used to supply air (air 16), vent air, and supply fixed ballast (e.g., iron ore, magnetite or ferrite slurry, etc.) to the ballast adjustable chamber, or alternatively, a separate system may be used to supply the fixed ballast to the ballast adjustable chamber. It should be appreciated that the higher density fixed ballast will settle out and remain in the bottom of the ballast adjustable chamber, while water and air are moved into and out of the ballast adjustable chamber during ballasting and deballasting operations.
Referring again to
Referring again to
Referring now to
Referring now to
Next, as shown in
Moving now to
It should be appreciated that the depth of water 15 limits the maximum draft depth to which second barge 40 and vessel 90 may be ballasted. If the desired draft depth of second barge 40 or vessel 90 exceeds the depth of water 15, this process may be performed at a different location (e.g., further offshore) where the depth of water 15 is sufficient. During the deployment and installation of assembly 11, first barge 20 is positioned in bay 47 of second barge 40, and subsequently, vessel 90 is positioned in bay 47 of second barge 40. In general, the positioning of first barge 20 within bay 47 requires the movement of first barge 20 relative to second barge 40 and the positioning of vessel 90 within bay 47 requires the movement of vessel 90 relative to second barge 40. In general, the relative movement of first barge 20 and second barge 40 may be accomplished by moving first barge 20 and/or second barge 40. Likewise, the relative movement of second barge 40 relative to vessel 90 may be accomplished by moving second barge 40 and/or vessel 90.
Referring now to
Referring briefly to
A plurality of cables or rods (not shown) are suspended from and hang down from upper frames 183. As will be described in more detail below, module assembly 11 is suspended from the cables or rods, and thus, bridge support assembly 181 and such cables or rods are sized and configured to support the entire weight of module assembly 11.
Referring now to
Referring now to
Next, as shown in
Moving now to
As previously described, the depth of water 15 limits the maximum draft depth to which barge 40 and vessel 90 may be ballasted. If the desired draft depth of barge 40 or vessel 90 exceeds the depth of water 11, this process may be performed at a different location (e.g., further offshore) where the depth of water 15 is sufficient. Also, during the deployment and installation of assembly 11, first barge 20 is positioned in bay 47 of second barge 40, and subsequently, vessel 90 is positioned in bay 47 of second barge 40. In general, the positioning of first barge 20 within bay 47 requires the movement of first barge 20 relative to second barge 40 and the positioning of vessel 90 within bay 47 requires the movement of vessel 90 relative to second barge 40. In general, the relative movement of first barge 20 and second barge 40 may be accomplished by moving first barge 20 and/or second barge 40. Likewise, the relative movement of second barge 40 relative to vessel 90 may be accomplished by moving second barge 40 and/or vessel 90.
Referring now to
Referring now to
Each rail 211 is aligned with and abuts end-to-end with a corresponding skidway or rail 221 extending along integration area 220. In this embodiment, rails 221, 211 are coupled together end-to-end. A carriage 230 is moveably coupled to each set of aligned rails 221, 211. Thus, each carriage 230 may be moved back-and-forth along its corresponding rails 211, 221. A module support system 80 as previously described is provided on carriages 230. In particular, a plurality of support members 81 are mounted to the top of each carriage 230.
Referring now to
Referring now to
Moving now to
As previously described, in this embodiment, module support system 80 is employed to support module assembly 11 as it is positioned over vessel 90. However, in other embodiments, module support system 80 can be replaced with module support system 180 previously described.
Referring now to
Referring to
Referring now to
A ballast control system 330 controls the relative volumes of air 16 and water 15, 18 within pontoon 311. Specifically, ballast control system 330 comprises a pump or compressor 331, a conduit 332, an air supply line 333, a first valve 334 along air supply line 333, a second valve 335 along conduit 332. Conduit 332 has a first open end 332a disposed outside of pontoon 311 and a second open end 332b disposed within chamber 316. In order to ballast pontoon 311, valve 335 is opened and valve 334 is closed thereby allowing air 16 to escape out of the first open end 332a. As air 16 escapes out of first open end 332a, water 15, 18 flows through port 317 into chamber 316. Alternatively, in order to de-ballast pontoon 311, valve 335 is closed and valve 334 is opened, thereby allowing compressor 331 to pump air 16 through line 333 and open valve 334 and into conduit 332. As air 16 is pumped into chamber 316 via conduit 332, water 15, 18 is forced out of port 317. Pontoons 311 are preferably ballasted and de-ballasted at the same rate and to the same degree to maintain pontoons 311 at substantially the same draft relative to the surface of water 15.
Referring again to
Rail assembly 310 is releasably coupled to integration area 220. In particular, pontoons 311 are tied to integration area 220 with mooring lines as is conventionally employed for load-out operations. When rail assembly 310 is coupled to integration area 220, each rail 312 is aligned with and abuts end-to-end with a corresponding rail 221 on integration area 220. In this embodiment, rails 312, 221 are releasably coupled end-to-end. One carriage 230 as previously described is moveably coupled to each set of aligned rails 221, 312. Thus, when assembly 310 is coupled to integration area 220, each carriage 230 may be moved back-and-forth along its corresponding rails 221, 312. In this embodiment, module support system 80 as previously described is mounted to carriages 230.
Referring still to
Referring now to
Moving now to
Moving now to
It should be appreciated that this embodiment allows the transfer of module assembly 11 from rail assembly 310 to vessel 90 at a distance from integration area 220. As a result, assembly 310 and/or vessel 90 may be ballasted to a greater degree in such offshore deeper waters.
As previously described, in this embodiment, module support system 80 is employed to releasably connect to module assembly 11, and support assembly 11 as it is positioned over vessel 90. However, in other embodiments, module support system 80 of system 300 can be replaced with module support system 180 previously described.
While preferred embodiments have been shown and described, modifications thereof can be made by one skilled in the art without departing from the scope or teachings herein. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the systems, apparatus, and processes described herein are possible and are within the scope of the invention. For example, the relative dimensions of various parts, the materials from which the various parts are made, and other parameters can be varied. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. Unless expressly stated otherwise, the steps in a method claim may be performed in any order. The recitation of identifiers such as (a), (b), (c) or (1), (2), (3) before steps in a method claim are not intended to and do not specify a particular order to the steps, but rather are used to simplify subsequent reference to such steps.
This application claims benefit of U.S. provisional patent application Ser. No. 61/528,852 filed Aug. 30, 2011, and entitled “Methods and Systems for FPSO Deck Making,” which is hereby incorporated herein by reference in its entirety.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4729695 | Silvestri | Mar 1988 | A |
| 5924822 | Finn et al. | Jul 1999 | A |
| 6299383 | Finn et al. | Oct 2001 | B1 |
| 6935810 | Horton | Aug 2005 | B2 |
| 7527006 | Khachaturian | May 2009 | B2 |
| 7610869 | Thomas | Nov 2009 | B2 |
| Number | Date | Country |
|---|---|---|
| 1060982 | Dec 2000 | EP |
| 20110083241 | Jul 2011 | KR |
| 0153609 | Jul 2001 | WO |
| 2004110855 | Dec 2004 | WO |
| 2010098898 | Sep 2010 | WO |
| Entry |
|---|
| PCT/US2012/053175 International Search Report and Written Opinion Dated Feb. 27, 2013 (11 p.). |
| Number | Date | Country | |
|---|---|---|---|
| 20130233224 A1 | Sep 2013 | US |
| Number | Date | Country | |
|---|---|---|---|
| 61528852 | Aug 2011 | US |
