US20110142546A1 - Self-Standing Riser System Having Multiple Buoyancy Chambers - Google Patents
Self-Standing Riser System Having Multiple Buoyancy Chambers Download PDFInfo
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- US20110142546A1 US20110142546A1 US13/033,991 US201113033991A US2011142546A1 US 20110142546 A1 US20110142546 A1 US 20110142546A1 US 201113033991 A US201113033991 A US 201113033991A US 2011142546 A1 US2011142546 A1 US 2011142546A1
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- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B17/00—Drilling rods or pipes; Flexible drill strings; Kellies; Drill collars; Sucker rods; Cables; Casings; Tubings
- E21B17/01—Risers
- E21B17/012—Risers with buoyancy elements
Definitions
- the present invention relates generally to self-standing riser assemblies utilized during oil and gas exploration and production operations, and in a particular though non-limiting embodiment, to a self-standing riser system equipped with multiple buoyancy chambers suitable for deployment in a variety of water depths and sea conditions.
- SSR Self-standing risers
- Known SSR can be used to facilitate standard “shallow-water” (e.g., between 0 feet and around 600 feet of water) drilling units and cost effective production facilities by placing blow-out preventers and production trees on top of a buoyancy chamber.
- a self-standing riser system suitable for deepwater oil and gas exploration and production including a lower riser assembly disposed in communication with a primary well-drilling fixture; one or more intermediate buoyancy chambers disposed in communication with the lower riser assembly and one or more portions of intermediate riser assembly, wherein one or more of the buoyancy chambers further includes an open-bottomed lower surface portion; and an upper riser assembly disposed in communication with one or more upper buoyancy chambers, wherein one or more of the upper buoyancy chambers further includes a fully enclosed portion.
- Ballast loads for the chambers are also provided.
- stress joints for the riser assemblies are also provided.
- methods and means of system deployment and maintenance access to blow-out preventers, wellheads and production trees; and various system interconnections are also provided.
- FIG. 1A is a schematic diagram of a self-standing riser system equipped with an open-bottom buoyancy chamber in calm waters, according to an example embodiment known in the prior art.
- FIG. 1B is a schematic diagram of a self-standing riser system equipped with an open-bottomed buoyancy chamber that is nearing its spill point.
- FIG. 1C is a schematic diagram of a self-standing riser equipped with an open-bottomed buoyancy chamber that has tilted beyond its spill point.
- FIG. 2 is a schematic diagram depicting the effects of pressure, temperature and depth on a closed-bottom buoyancy chamber.
- FIG. 3 is a schematic diagram of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the present invention.
- FIG. 4 is a schematic diagram depicting the installation of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the invention.
- the closed container design is similar in some respects to a submarine, in that there are typically one or more ballast chambers used to house a fluid, such as a light gas, seawater, etc. Once a desired ratio of fluids is achieved, the chamber is closed off by valves or other means known in the art.
- a fluid such as a light gas, seawater, etc.
- An open-bottomed buoyancy chamber includes many design functions similar to those of the closed container design. However, once desired buoyancy characteristics are achieved, fluid disposed within the chamber is simply trapped by the sides and top thereof.
- FIG. 1A illustrates a known, open-bottomed, buoyancy chamber disposed in communication with an SSR and filled with a fluid, for example, a pressurized gas.
- a fluid for example, a pressurized gas.
- FIG. 1B also illustrates how the fluid contained within the chamber has shifted relative to the system's tilt away from its vertical axis.
- the chamber can accommodate a tilt of up to a certain critical angle (which depends largely on its design dimensions) before the critical spill point angle is reached, and fluid begins to escape from the chamber.
- FIG. 1C further illustrates how the spill rate of the gas contained within an open-bottomed buoyancy chamber will increase as the critical tilt angle is reached and exceeded.
- spillage will result in even greater loss of buoyancy, and therefore a proportionately increasing tilt angle, which will cause more and more gas to escape from the chamber.
- enough gas escapes that the buoyant force is reduced to the point where the chamber can no longer support the riser, thereby causing the system to fail.
- open-bottomed chambers can operate at extreme water depths with a reduced concern of structural collapse than a closed system, since the open design allows fluid pressures within the chamber to equalize with surrounding pressures at even great depths. Furthermore, the open-bottomed design has less overall system weight due to a reduction in required construction materials, since there is no bottom, and the remainder of the shell will require less thickness and reinforcement in order to withstand deepwater fluid pressures.
- closed container buoyancy chambers do not suffer as greatly from the problem of tilting caused by currents and surface effects, and are typically the appropriate design choice in areas where currents and surface effects are significant enough to cause major lateral displacement from the vertical axis.
- a leak for example, a leak caused by container breach, valve malfunction, etc.
- the gas or other fluid will escape and the SSR can fail, as illustrated in FIG. 1C .
- Closed container buoyancy chambers must also be robust enough to offset external forces such as deepwater fluid pressure. As illustrated in FIG. 2 , such chambers must, as a threshold matter, have sufficient structural integrity and wall thickness to resist expected pressures that might cause a collapse of the chamber's outer shell. Moreover, when deploying a closed buoyancy chamber filled with a gas, the internal gas pressures and temperatures should be sufficiently proportional to the external water pressures and temperatures that an associated pressure or temperature gradient will not induce an effective change in gas volume within the chamber which could cause the chamber's outer shell to crack or collapse.
- SSR systems are constrained to include the use of only a single buoyancy chamber due to the chamber's large size.
- the larger buoyancy chamber designs increase the time and cost associated with building and deploying the operating system.
- deployment of large, pressurized chamber at great depths e.g., >500 ft. or so
- the diameter of the buoyancy chamber is increased, the probability of structural failure and warping caused by handling during construction and deployment is also increased.
- an SSR system 14 comprising a plurality of subordinate buoyancy chambers configured to admit to installation in deeper water depths than any previously known SSR systems.
- SSR 14 can be stacked with multiple buoyancy chambers as illustrated in FIGS. 4A , 4 B, 4 C and 4 D.
- FIG. 3 Although illustrated in FIG. 3 as a combination of lower SSR assembly 10 and upper SSR assembly 12 , embodiments of the overall SSR system 14 can comprise any number of individual SSR assemblies.
- lower SSR assembly 10 is first deployed.
- a specially designed vessel equipped specifically to deploy buoyancy chambers and SSR assemblies is used.
- lower SSR assembly 10 is joined in mechanical communication with a casing wellhead established near the mud-line.
- the casing wellhead has been preset into a well hole bored into an associated seafloor surface.
- one or more intermediate buoyancy chambers 16 is attached to lower SSR assembly 10 , thereby providing increased stability in deep or turbulent waters.
- intermediate buoyancy chamber 16 can comprise a closed-container design, but in most instances will comprise the open-bottomed design for the reasons described above, with the only firm requirement being that intermediate chamber 16 must in any event be capable of providing the support required to control lower SSR assembly 10 and upper SSR assembly 14 .
- intermediate buoyancy chamber 16 is disposed in mechanical communication with either previously known or custom-designed drilling, production and exploration equipment.
- the top and bottom portions of an intermediate buoyancy chamber may comprise one or more of a blowout preventer, a production tree, or a wellhead that functions in a manner similar to the casing wellhead placed near mud-line of the ocean floor.
- Attachment of the drilling, production and exploration equipment can be achieved using either known or custom connection and fastening members, e.g., hydraulic couplers, various nut and bolt assemblies, welded joints, pressure fittings (either with or without gaskets), swaging, etc., without departing from the scope of the invention.
- an upper SSR assembly 12 is deployed and disposed in mechanical communication with a wellhead, blowout preventer, or production tree (or another, custom-designed device combining elements of one or more of such devices) installed atop an upper surface of the intermediate chamber 16 or a connecting member associated therewith. According to other example embodiments, the installation process continues until the desired number of such assemblies are installed in serial communication with one another in order to achieve a stable and efficient SSR system 14 , as depicted in FIGS. 4A-4D .
- example embodiments can utilize stress joints 22 , as depicted in FIG. 3 .
- Stress joints 22 can comprise any known material, for example, a plastic, rubber, or metal material, but should in any event be capable of maintaining the SSR 14 system's structural integrity and overall stability.
- a plurality of upper buoyancy chambers 18 , 20 includes an open-bottomed chamber 18 and a closed-container type chamber 20 .
- all of the chambers in the system are either open or closed, and in still further embodiments, combinations of open and closed chambers are employed across the system.
- the multiple open-bottomed design buoyancy chambers are utilized to facilitate deployment in deeper waters in which surrounding fluid pressures are greatest.
- Other embodiments utilize a plurality of closed-container type chambers disposed near the top of the SSR system 14 , thereby improving the system's overall stability and balance. Such configurations can also help avoid the system's tendency to tilt away from its vertical axis as a result of external lateral forces, such as a forceful cross-current.
- a plurality of buoyancy chambers disposed in mechanical communication with upper SSR assembly 12 allows for the overall SSR system 14 to maintain required functionality and stability in varying water depths and conditions, thereby improving its efficiency and operability.
- a blowout preventer for example, a blowout preventer, a production tree, or a wellhead designed to function in a manner similar to the casing wellhead placed near mud-line of the ocean floor.
- the buoyancy chambers utilized throughout the system further comprise auxiliary buoyancy materials, such as syntactic foam or air filled glass micro-spheres that lend buoyancy to the system. Injecting one or more of these materials within an open-bottomed chamber will assist in prevention of buoyancy fluid (e.g., gas, liquid, etc.) loss should tilting occur, or if there is a breach or failure of tubing, valves, or other equipment utilized in connection with the buoyancy chamber.
- auxiliary buoyancy materials such as syntactic foam or air filled glass micro-spheres that lend buoyancy to the system. Injecting one or more of these materials within an open-bottomed chamber will assist in prevention of buoyancy fluid (e.g., gas, liquid, etc.) loss should tilting occur, or if there is a breach or failure of tubing, valves, or other equipment utilized in connection with the buoyancy chamber.
- FIG. 4A a deployment vessel deploys a lower SSR assembly 40 to the ocean floor where it is mechanically disposed in communication with a casing wellhead near the mud-line.
- FIG. 4A further depicts an intermediate buoyancy chamber 41 installed atop the SSR assembly 40 .
- the intermediate buoyancy chamber 41 further comprise one or more previously known or custom-fit attachment mechanisms, such as a combined blowout preventer and production tree, so that the intermediate chamber 41 is useful during operations for purposes other than mere connection with an upper SSR assembly 42 .
- a plurality of intermediate buoyancy chambers 41 are deployed and mechanically disposed in communication with a previously installed SSR assembly or another intermediate buoyancy chamber (see, for example, FIGS. 4B-4D ).
- intermediate SSR assemblies 42 and 44 are deployed and disposed in mechanical communication with a well-head affixed atop intermediate buoyancy chamber 41 .
- additional intermediate buoyancy chambers 41 , 43 , 45 serve as additional support and connection components for the intermediate SSR assemblies.
- Such redundant embodiments can achieve heretofore unknown SSR system depths of more than 15,000 ft. with the addition of multiple intermediate SSR assemblies.
- FIG. 4D further depicts an embodiment employing a plurality of buoyancy chambers 47 atop SSR assembly 46 in order to complete the overall SSR system 50 .
- embodiments of the plurality of buoyancy chambers 47 can comprise a mixture of open-bottomed and closed-container designs, or any other configuration made desirable by operating conditions, including of course the installation of only a single such chamber.
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Abstract
A multi-tiered self-standing riser system includes one or more intermediate buoyancy chambers configured to provide an upward lifting force on strings of associated riser assemblies. The intermediate chambers have either an open-bottomed or closed container design. The chambers can further include an auxiliary buoyant material designed to either mix with or contain pressurized fluids injected into the chambers. The self-standing riser system further includes a lower riser assembly affixed to a primary well-drilling fixture. The system also includes an upper riser assembly and one or more additional buoyancy chambers disposed in either direct or indirect communication with one another, as well as with drilling, production and exploration equipment as required by associated operations.
Description
- The present application is a continuation of U.S. Non-Provisional application Ser. No. 12/274,124 filed Nov. 19, 2008, still pending, which claims the benefit of prior U.S. Provisional Application No. 61/003,647, filed Nov. 19, 2007.
- The present invention relates generally to self-standing riser assemblies utilized during oil and gas exploration and production operations, and in a particular though non-limiting embodiment, to a self-standing riser system equipped with multiple buoyancy chambers suitable for deployment in a variety of water depths and sea conditions.
- Self-standing risers (hereinafter “SSR”) are employed in the oil and gas industry to suspend production and injection lines from subsea production units, and to support holding tendons associated with floating offshore structures. Known SSR can be used to facilitate standard “shallow-water” (e.g., between 0 feet and around 600 feet of water) drilling units and cost effective production facilities by placing blow-out preventers and production trees on top of a buoyancy chamber.
- The conventional approach to the SSR design has been to employ one large buoyancy chamber that supports the riser or tendon loads. However, this approach has led to increased costs associated with the construction and installation of the buoyancy chambers. Such factors have resulted in a lack of significant SSR system development by operators who could realize a broad spectrum of associated benefits. Nonetheless, the industry as a whole desires a reduction in oil and gas production costs, a decrease in time delays for drilling exploration wells, and increased development of previously discovered fields. There is, therefore, a long-felt but unmet need for smaller, more flexible riser systems capable of more rapid manufacture and deployment that assist in the profitable development of previously under produced oil and gas fields.
- A self-standing riser system suitable for deepwater oil and gas exploration and production is provided, the system including a lower riser assembly disposed in communication with a primary well-drilling fixture; one or more intermediate buoyancy chambers disposed in communication with the lower riser assembly and one or more portions of intermediate riser assembly, wherein one or more of the buoyancy chambers further includes an open-bottomed lower surface portion; and an upper riser assembly disposed in communication with one or more upper buoyancy chambers, wherein one or more of the upper buoyancy chambers further includes a fully enclosed portion.
- Ballast loads for the chambers; stress joints for the riser assemblies; methods and means of system deployment and maintenance; access to blow-out preventers, wellheads and production trees; and various system interconnections are also provided.
- The embodiments disclosed herein will be better understood, and numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
-
FIG. 1A is a schematic diagram of a self-standing riser system equipped with an open-bottom buoyancy chamber in calm waters, according to an example embodiment known in the prior art. -
FIG. 1B is a schematic diagram of a self-standing riser system equipped with an open-bottomed buoyancy chamber that is nearing its spill point. -
FIG. 1C is a schematic diagram of a self-standing riser equipped with an open-bottomed buoyancy chamber that has tilted beyond its spill point. -
FIG. 2 is a schematic diagram depicting the effects of pressure, temperature and depth on a closed-bottom buoyancy chamber. -
FIG. 3 is a schematic diagram of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the present invention. -
FIG. 4 is a schematic diagram depicting the installation of a self-standing riser system comprising multiple buoyancy chambers, according to example embodiments of the invention. - There are presently two known types of submersible buoyancy chambers suitable for oil and gas exploration and production: a closed container design, and an open-bottomed design. Both types of chambers, if pressurized and secured by a riser, will exert an upward lifting force on the riser. Certain embodiments also comprise features lending adjustability to the system, as may be known to those of skill in the art.
- The closed container design is similar in some respects to a submarine, in that there are typically one or more ballast chambers used to house a fluid, such as a light gas, seawater, etc. Once a desired ratio of fluids is achieved, the chamber is closed off by valves or other means known in the art.
- An open-bottomed buoyancy chamber includes many design functions similar to those of the closed container design. However, once desired buoyancy characteristics are achieved, fluid disposed within the chamber is simply trapped by the sides and top thereof.
-
FIG. 1A illustrates a known, open-bottomed, buoyancy chamber disposed in communication with an SSR and filled with a fluid, for example, a pressurized gas. As seen, a combination of calm water currents, minimal external forces, and a sufficient amount of buoyancy applied to the SSR results in minimal lateral displacement force. Accordingly, the buoyancy chamber illustrated inFIG. 1A experiences little or no tilt relative to its vertical axis, and fluid contained within the chamber remains enclosed. - If, however, a sufficiently large enough force is applied to the chamber, such as a strong current as depicted in
FIG. 1B , the SSR will begin to tilt away from its vertical axis.FIG. 1B also illustrates how the fluid contained within the chamber has shifted relative to the system's tilt away from its vertical axis. However, the chamber can accommodate a tilt of up to a certain critical angle (which depends largely on its design dimensions) before the critical spill point angle is reached, and fluid begins to escape from the chamber. -
FIG. 1C further illustrates how the spill rate of the gas contained within an open-bottomed buoyancy chamber will increase as the critical tilt angle is reached and exceeded. In particular, spillage will result in even greater loss of buoyancy, and therefore a proportionately increasing tilt angle, which will cause more and more gas to escape from the chamber. Eventually, enough gas escapes that the buoyant force is reduced to the point where the chamber can no longer support the riser, thereby causing the system to fail. - Despite such drawbacks, open-bottomed chambers can operate at extreme water depths with a reduced concern of structural collapse than a closed system, since the open design allows fluid pressures within the chamber to equalize with surrounding pressures at even great depths. Furthermore, the open-bottomed design has less overall system weight due to a reduction in required construction materials, since there is no bottom, and the remainder of the shell will require less thickness and reinforcement in order to withstand deepwater fluid pressures.
- In contrast, closed container buoyancy chambers do not suffer as greatly from the problem of tilting caused by currents and surface effects, and are typically the appropriate design choice in areas where currents and surface effects are significant enough to cause major lateral displacement from the vertical axis. However, if either of the described buoyancy chambers sustain a leak (for example, a leak caused by container breach, valve malfunction, etc.), the gas or other fluid will escape and the SSR can fail, as illustrated in
FIG. 1C . - Closed container buoyancy chambers must also be robust enough to offset external forces such as deepwater fluid pressure. As illustrated in
FIG. 2 , such chambers must, as a threshold matter, have sufficient structural integrity and wall thickness to resist expected pressures that might cause a collapse of the chamber's outer shell. Moreover, when deploying a closed buoyancy chamber filled with a gas, the internal gas pressures and temperatures should be sufficiently proportional to the external water pressures and temperatures that an associated pressure or temperature gradient will not induce an effective change in gas volume within the chamber which could cause the chamber's outer shell to crack or collapse. - Typically, SSR systems are constrained to include the use of only a single buoyancy chamber due to the chamber's large size. However, the larger buoyancy chamber designs increase the time and cost associated with building and deploying the operating system. Moreover, deployment of large, pressurized chamber at great depths (e.g., >500 ft. or so) can prove to be an exceedingly difficult task. Furthermore, as the diameter of the buoyancy chamber is increased, the probability of structural failure and warping caused by handling during construction and deployment is also increased.
- The detailed description that follows includes exemplary systems, methods, and techniques that embody techniques of the presently inventive subject matter. However, it will be understood by those of skill in the art that the described embodiments may be practiced without one or more of the specific details disclosed herein. In other instances, well-known manufacturing equipment, protocols, structures and techniques have not been shown in detail in order to avoid obfuscation in the description.
- Referring now to the example embodiment depicted in
FIG. 3 , anSSR system 14 is depicted comprising a plurality of subordinate buoyancy chambers configured to admit to installation in deeper water depths than any previously known SSR systems. According to an alternative embodiment,SSR 14 can be stacked with multiple buoyancy chambers as illustrated inFIGS. 4A , 4B, 4C and 4D. Although illustrated inFIG. 3 as a combination oflower SSR assembly 10 andupper SSR assembly 12, embodiments of theoverall SSR system 14 can comprise any number of individual SSR assemblies. - In the embodiment depicted in
FIG. 3 ,lower SSR assembly 10 is first deployed. In one example, a specially designed vessel equipped specifically to deploy buoyancy chambers and SSR assemblies is used. Following deployment,lower SSR assembly 10 is joined in mechanical communication with a casing wellhead established near the mud-line. In a typical embodiment, the casing wellhead has been preset into a well hole bored into an associated seafloor surface. - In further embodiments, one or more
intermediate buoyancy chambers 16 is attached to lowerSSR assembly 10, thereby providing increased stability in deep or turbulent waters. Depending on operating conditions,intermediate buoyancy chamber 16 can comprise a closed-container design, but in most instances will comprise the open-bottomed design for the reasons described above, with the only firm requirement being thatintermediate chamber 16 must in any event be capable of providing the support required to controllower SSR assembly 10 andupper SSR assembly 14. - In further example embodiments,
intermediate buoyancy chamber 16 is disposed in mechanical communication with either previously known or custom-designed drilling, production and exploration equipment. Thus, for example, the top and bottom portions of an intermediate buoyancy chamber may comprise one or more of a blowout preventer, a production tree, or a wellhead that functions in a manner similar to the casing wellhead placed near mud-line of the ocean floor. Attachment of the drilling, production and exploration equipment can be achieved using either known or custom connection and fastening members, e.g., hydraulic couplers, various nut and bolt assemblies, welded joints, pressure fittings (either with or without gaskets), swaging, etc., without departing from the scope of the invention. - In further embodiments, an
upper SSR assembly 12 is deployed and disposed in mechanical communication with a wellhead, blowout preventer, or production tree (or another, custom-designed device combining elements of one or more of such devices) installed atop an upper surface of theintermediate chamber 16 or a connecting member associated therewith. According to other example embodiments, the installation process continues until the desired number of such assemblies are installed in serial communication with one another in order to achieve a stable andefficient SSR system 14, as depicted inFIGS. 4A-4D . - In order to further stabilize the
SSR system 14, example embodiments can utilizestress joints 22, as depicted inFIG. 3 . Stress joints 22 can comprise any known material, for example, a plastic, rubber, or metal material, but should in any event be capable of maintaining theSSR 14 system's structural integrity and overall stability. - Consistent with the
example SSR system 14 illustrated inFIG. 3 , a plurality ofupper buoyancy chambers chamber 18 and a closed-container type chamber 20. In a one example embodiment, at least one of said upper chambers—generally the topmost—will comprise a closed design, while others in the system, includingintermediate chamber 16, will comprise an open-bottomed design. In another example embodiment, all of the chambers in the system are either open or closed, and in still further embodiments, combinations of open and closed chambers are employed across the system. - In some embodiments, the multiple open-bottomed design buoyancy chambers are utilized to facilitate deployment in deeper waters in which surrounding fluid pressures are greatest. Other embodiments utilize a plurality of closed-container type chambers disposed near the top of the
SSR system 14, thereby improving the system's overall stability and balance. Such configurations can also help avoid the system's tendency to tilt away from its vertical axis as a result of external lateral forces, such as a forceful cross-current. - In still further embodiments, a plurality of buoyancy chambers disposed in mechanical communication with
upper SSR assembly 12 allows for theoverall SSR system 14 to maintain required functionality and stability in varying water depths and conditions, thereby improving its efficiency and operability. - Further example embodiments comprise a plurality of upper buoyancy chambers disposed in mechanical communication with commonly known drilling, production and exploration equipment. Thus, for example, the top and bottom portions of an upper buoyancy chamber may comprise one or more of a blowout preventer, a production tree, or a wellhead designed to function in a manner similar to the casing wellhead placed near mud-line of the ocean floor.
- In further embodiments, the buoyancy chambers utilized throughout the system further comprise auxiliary buoyancy materials, such as syntactic foam or air filled glass micro-spheres that lend buoyancy to the system. Injecting one or more of these materials within an open-bottomed chamber will assist in prevention of buoyancy fluid (e.g., gas, liquid, etc.) loss should tilting occur, or if there is a breach or failure of tubing, valves, or other equipment utilized in connection with the buoyancy chamber.
- In the example embodiment illustrated in
FIG. 4A , a deployment vessel deploys alower SSR assembly 40 to the ocean floor where it is mechanically disposed in communication with a casing wellhead near the mud-line.FIG. 4A further depicts anintermediate buoyancy chamber 41 installed atop theSSR assembly 40. Various embodiments of theintermediate buoyancy chamber 41 further comprise one or more previously known or custom-fit attachment mechanisms, such as a combined blowout preventer and production tree, so that theintermediate chamber 41 is useful during operations for purposes other than mere connection with anupper SSR assembly 42. In various other embodiments, a plurality ofintermediate buoyancy chambers 41 are deployed and mechanically disposed in communication with a previously installed SSR assembly or another intermediate buoyancy chamber (see, for example,FIGS. 4B-4D ). - In
FIG. 4C ,intermediate SSR assemblies intermediate buoyancy chamber 41. In some example embodiments, additionalintermediate buoyancy chambers - In the example embodiment depicted in
FIG. 4D , afinal SSR assembly 46 is deployed to complete theSSR system 50.FIG. 4D further depicts an embodiment employing a plurality ofbuoyancy chambers 47 atopSSR assembly 46 in order to complete theoverall SSR system 50. As previously discussed, embodiments of the plurality ofbuoyancy chambers 47 can comprise a mixture of open-bottomed and closed-container designs, or any other configuration made desirable by operating conditions, including of course the installation of only a single such chamber. - The foregoing specification is provided for illustrative purposes only, and is not intended to describe all possible aspects of the present invention. Moreover, while the invention has been shown and described in detail with respect to several exemplary embodiments, those of ordinary skill in the art will appreciate that minor changes to the description, and various other modifications, omissions and additions may also be made without departing from the spirit or scope thereof.
Claims (16)
1. A self-standing riser system suitable for deepwater oil and gas exploration and production, said system comprising:
a lower riser assembly disposed in communication with a primary well-drilling fixture;
one or more intermediate buoyancy chambers disposed in communication with said lower riser assembly and one or more portions of intermediate riser assembly, wherein one or more of said buoyancy chambers further comprises an open-bottomed portion; and
an upper riser assembly disposed in communication with one or more upper buoyancy chambers, wherein one or more of said upper buoyancy chambers further comprises an open-bottomed portion.
2. The self-standing riser of claim 1 , wherein each of said open-bottomed intermediate buoyancy chambers further comprises a fluid ballast.
3. The self-standing riser system of claim 2 , wherein said fluid ballast further comprises a gas ballast.
4. The self-standing riser system of claim 2 , wherein said fluid ballast further comprises a liquid ballast.
5. The self-standing riser system of claim 2 , wherein said fluid ballast further comprises a ballast including both a liquid and a gas.
6. The self-standing riser system of claim 2 , wherein said fluid ballast further comprises an auxiliary ballast that lends additional pressure and density to said fluid.
7. The self-standing riser system of claim 6 , wherein said auxiliary ballast retards the escape of fluid from within said open-bottomed intermediate buoyancy chambers in the event said chambers tilt beyond a critical angle relative to its vertical axis.
8. The self-standing riser system of claim 1 , wherein one or more of said intermediate buoyancy chambers further comprises a closed bottom portion.
9. The self-standing riser system of claim 1 , wherein one or more of said upper buoyancy chambers further comprises a closed bottom portion.
10. The self standing riser system of claim 1 , wherein each of said open-bottomed upper buoyancy chambers further comprises a fluid ballast.
11. The self-standing riser system of claim 10 , wherein said fluid ballast further comprises a gas ballast.
12. The self-standing riser system of claim 10 , wherein said fluid ballast further comprises a liquid ballast.
13. The self-standing riser system of claim 10 , wherein said fluid ballast further comprises a ballast including both a liquid and a gas.
14. The self-standing riser system of claim 10 , wherein said fluid ballast further comprises an auxiliary ballast that lends additional pressure and density to said fluid.
15. The self-standing riser system of claim 14 , wherein said auxiliary ballast retards the escape of fluid from within said open-bottomed intermediate buoyancy chambers in the event said chambers tilt beyond a critical angle relative to its vertical axis.
16. The self-standing riser system of claim 1 , wherein one or more lengths of said lower riser assembly and said upper riser assembly further comprises one or more stress joints for absorbing stress accumulated within said lengths of said assemblies.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US13/033,991 US20110142546A1 (en) | 2007-11-19 | 2011-02-24 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
US13/938,773 US20140166296A1 (en) | 2007-11-19 | 2013-07-10 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US364707P | 2007-11-19 | 2007-11-19 | |
US12/274,124 US20090126937A1 (en) | 2007-11-19 | 2008-11-19 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
US13/033,991 US20110142546A1 (en) | 2007-11-19 | 2011-02-24 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Related Parent Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US12/274,124 Continuation US20090126937A1 (en) | 2007-11-19 | 2008-11-19 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Related Child Applications (1)
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---|---|---|---|
US201213674658A Continuation | 2007-11-19 | 2012-11-12 |
Publications (1)
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Application Number | Title | Priority Date | Filing Date |
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US12/274,124 Abandoned US20090126937A1 (en) | 2007-11-19 | 2008-11-19 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
US13/033,991 Abandoned US20110142546A1 (en) | 2007-11-19 | 2011-02-24 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
US13/938,773 Abandoned US20140166296A1 (en) | 2007-11-19 | 2013-07-10 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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US12/274,124 Abandoned US20090126937A1 (en) | 2007-11-19 | 2008-11-19 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
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US13/938,773 Abandoned US20140166296A1 (en) | 2007-11-19 | 2013-07-10 | Self-Standing Riser System Having Multiple Buoyancy Chambers |
Country Status (7)
Country | Link |
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US (3) | US20090126937A1 (en) |
CN (1) | CN101939491B (en) |
AP (1) | AP2010005290A0 (en) |
AU (1) | AU2008326408B2 (en) |
MX (1) | MX2010005485A (en) |
NO (1) | NO20100889L (en) |
WO (1) | WO2009067532A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20130252493A1 (en) * | 2010-03-01 | 2013-09-26 | Charles R. Yemington | Rigid Hull Gas-Can Buoys Variable Buoyancy |
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US7640738B1 (en) | 2002-06-19 | 2010-01-05 | Hydro-Gear Limited Partnership Ltd. | Hydraulic pump and motor module for use in a vehicle |
CN101191408A (en) * | 2007-12-27 | 2008-06-04 | 中国海洋石油总公司 | Ocean underwater device |
AU2009312647B2 (en) * | 2008-11-05 | 2016-01-14 | Technip France | Method for assembling an operating rig for a fluid in a body of water and associated operating rig |
US8657012B2 (en) | 2010-11-01 | 2014-02-25 | Vetco Gray Inc. | Efficient open water riser deployment |
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- 2008-11-19 AU AU2008326408A patent/AU2008326408B2/en not_active Ceased
- 2008-11-19 US US12/274,124 patent/US20090126937A1/en not_active Abandoned
- 2008-11-19 MX MX2010005485A patent/MX2010005485A/en not_active Application Discontinuation
- 2008-11-19 WO PCT/US2008/084057 patent/WO2009067532A1/en active Application Filing
- 2008-11-19 CN CN200880117681.2A patent/CN101939491B/en not_active Expired - Fee Related
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2010
- 2010-06-21 NO NO20100889A patent/NO20100889L/en not_active Application Discontinuation
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2011
- 2011-02-24 US US13/033,991 patent/US20110142546A1/en not_active Abandoned
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2013
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Also Published As
Publication number | Publication date |
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AU2008326408A1 (en) | 2009-05-28 |
CN101939491A (en) | 2011-01-05 |
US20140166296A1 (en) | 2014-06-19 |
AU2008326408B2 (en) | 2014-10-16 |
WO2009067532A1 (en) | 2009-05-28 |
MX2010005485A (en) | 2011-06-16 |
US20090126937A1 (en) | 2009-05-21 |
AP2010005290A0 (en) | 2010-06-30 |
CN101939491B (en) | 2013-02-27 |
NO20100889L (en) | 2010-07-28 |
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