Patent Application
20120090524
Not applicable
Not applicable
1. Field of the Invention
The present invention relates to a method of installing a floating marine platform. More particularly, the present invention relates to a marine platform and a method of installing a marine platform using multiple buoys that support a platform and wherein tensile anchor cables connect to a deck part of the platform at the center of the deck. In one embodiment, an improved buoy construction is provided with longitudinal, transverse and diagonal members (e.g., welded) and having a lower ballast section, upper buoyant section and intermediate neutral buoyancy section.
2. General Background of the Invention
Many types of marine platforms have been designed, patented, and/or used commercially. Marine platforms typically take the form of either fixed platforms that include a large underwater support structure or “jacket” or a floating platform having a submersible support. Sometimes these platforms are called semi-submersible rigs.
Jack-up barges are another type of platform that can be used in an offshore marine environment for drilling/production. Jack-up barges have a barge with long legs that can be powered up for travel and powered down to elevate the barge above the water.
Other types of platforms for deep water (for example, 1500 feet (457.2 meters) or deeper) have been patented such as spars and others. Some of the following patents relate to offshore platforms, some of which are buoy type offshore platforms, all of which are hereby incorporated herein by reference. Other patents have issued that relate in general to floating structures, and including some patents disclosing structures that would not be suitable for use in oil and gas well drilling and/or production. The following Table lists examples of marine platforms. The order of listing is numerical, and is otherwise of no significance.
One of the problems with single floater type marine platform constructions or “spars” is that the single floater must be enormous, and thus very expensive to manufacture, transport, and install. In a marine environment, such a structure must support an oil and gas well drilling rig or production platform weighing between 500 and 40,000 tons (between 454 to 36,287 metric tons), for example (or even a package of between 5,000-100,000 tons (4,536 to 90,718 metric tons)).
The present invention provides an improved offshore marine platform (and method of installation) that can be used for drilling for oil and/or gas or in the production of oil and gas from an offshore environment. Such drilling and/or production facilities typically can weigh between 500-100,000 tons (454-90,718 metric tons), and more commonly weigh between 3,000-50,000 tons (2,722-45,359 metric tons).
The apparatus of the present invention thus provides a marine platform that is comprised of a plurality of spaced apart buoys and a deck having a periphery that includes a plurality of attachment positions, one attachment position for each buoy. An articulating connection joins each buoy to the platform deck or superstructure.
Each of the buoys will move due to current and/or wind and/or wave action or due to other dynamic marine environmental factors. “Articulating connection” as used herein should be understood to mean any connection or joint that connects a buoy to the platform deck or superstructure, transmits axial and shear forces, and allows the support buoy(s) to move relative to the platform deck or superstructure without separation, and wherein the bending movement transferred to the platform deck or superstructure from one of the so connected buoys or from multiple of the so connected buoys is reduced, minimized or substantially eliminated.
“Articulating connection” is a joint movably connecting a buoy to a platform deck or superstructure wherein axial and tangential forces are substantially transmitted, however, transfer of bending movement is substantially reduced or minimized through the joint allowing relative movement between the buoy and the platform deck or superstructure.
An articulating connection connects each buoy to the platform at a respective attachment position, the connection allowing for sea state induced buoy motions while minimizing effects on the platform.
The apparatus of the present invention provides a marine platform that further comprises a mooring extending from the center of the platform to anchor points or anchors for holding the platform and buoys to a desired location.
In one embodiment, the present invention provides a marine platform wherein each of the articulating connections includes corresponding concave and convex engaging portions. In another embodiment, a universal type joint is disclosed.
In another embodiment a marine platform has buoys with convex articulating portions and the platform has correspondingly shaped concave articulating portions.
In one embodiment, each buoy can be provided with a concave articulating portion and the platform with a corresponding convex articulating portion that engages a buoy.
In one embodiment, each buoy has a height and a diameter. In a preferred embodiment, the height is much greater than the diameter for each of the buoys.
In one embodiment, each buoy is preferably between about 25 and 100 feet (7.6 and 30.5 meters) in diameter.
The apparatus of the present invention preferably provides a plurality of buoys. The buoys can be of a truss or lattice construction.
In a preferred embodiment, the platform is comprised of a trussed deck. The trussed deck preferably has lower horizontal members, upper horizontal members and a plurality of inclined members spanning between the upper and lower horizontal members, and wherein the attachment positions are next to the lower horizontal member.
In a preferred embodiment, the apparatus supports an oil and gas well drilling and/or production platform weighing between 500 and 100,000 tons (between 454 and 90,718 metric tons), more particularly, weighing between 3,000 and 50,000 tons (between 2,722 and 45,359 metric tons).
The apparatus of the present invention uses articulating connections between the submerged portion of the buoy and the platform deck or superstructure to minimize or reduce topside, wave induced motions during the structural life of the apparatus.
The apparatus of the present invention thus enables smaller, multiple hull components to be used to support the platform deck or superstructure rather than a single column or single buoy floater.
With the present invention, the topside angular motion is reduced and is less than the topside angular motion of a single column floater of comparable weight.
With the present invention, there is substantially no bending movement or minimum bending movement transferred between each buoy and the structure being supported. The present invention thus minimizes or substantially eliminates movement transfer at the articulating connection that is formed between each buoy and the structure being supported. The buoys are thus substantially free to move in any direction relative to the supported structure or load, excepting motion that would separate a buoy from the supported structure.
The present invention has particular utility in the supporting of oil and gas well drilling facilities and oil and gas well drilling production facilities. The apparatus of the present invention has particular utility in very deep water, for example, in excess of 1500 feet (457 meters).
The present invention also has particular utility in tropical environments (for example West Africa and Brazil) wherein the environment produces long period swell action.
The present invention provides a method of installing an oil and gas well facility such as a drilling facility or a production facility on a platform in an offshore deepwater marine environment. The term “deepwater” as used herein means water depths of in excess of 1500 feet (457 meters).
The method of the present invention contemplates the placement of a plurality of buoys at a selected offshore location, a portion of each of the buoys being underwater. A platform deck or superstructure extends above water and includes a platform having an oil and gas well facility. Such a facility can include oil well drilling, oil well production, or a combination of oil well drilling and production. The platform and its facility can be floated to a selected location. The platform includes a peripheral portion having a plurality of attachment positions, one attachment position for each buoy.
When the buoys and platform are located at a desired position, the platform is ballasted relative to the buoys until the buoys connect with the platform. This connection can be achieved by either ballasting the platform downwardly (such as for example, using a ballasted transport barge), or by ballasting the buoys to a higher position so that they engage the supported platform.
The platform can include a trussed deck that carries at or near its periphery or corners, connectors that enable a connection to be formed with the upper end portion of each buoy. As an example, there can be provided four buoys and four connectors on the trussed deck or platform.
If a trussed deck is employed, an oil well production facility (drilling or production or a combination) can be supported upon the trussed deck. The connector at the top of each buoy can be any type of an articulating connection that forms an articulation with the trussed deck or a connector on the trussed deck. In an alternate method, the multiple buoys can be used as part of an installation method to place the marine platform upon a single spar support.
For a further understanding of the nature, objects, and advantages of the present invention, reference should be had to the following detailed description, read in conjunction with the following drawings, wherein like reference numerals denote like elements and wherein:
In
The present invention provides buoys 13, 14, 15, 16 of improved configuration. The buoys 13, 14, 15, 16 are shown in a side view of each of the
Each of the buoys 13, 22 provides an upper buoyant floatation portion 23, a lower ballast portion 24 and a central neutrally buoyant portion 25 which can be flooded. In
In
In
The upper floatation or buoyant portion 23 of buoy 13 can be comprised of a plurality (for example, four) longitudinally extending corner members 35 which are connected with transverse members 36 at joints or welds 37 (see
In
Each of the ballast sections or ballast portions 24, 27 can be similarly configured. Each ballast section 24 or 27 can include longitudinally extending corner members 57, transverse members 56, and tapered sections 55 (see
In
In
In
Central portion 19 of platform 17 would be fitted with one interface device 95 as shown in
Each cable 20 or 21 could include chain and wire or rope or polyester portions. For example, there could be chain on the end that terminates on the chain sheave 92 and chain stoppers or chocks 90, 91. This chain would then connect to a wire rope or polyester rope or both (in a sequence).
All measurements disclosed herein are at standard temperature and pressure, at sea level on Earth, unless indicated otherwise.
The foregoing embodiments are presented by way of example only; the scope of the present invention is to be limited only by the following claims.
This is a non provisional patent application of U.S. Provisional Patent Application Ser. No. 61/385,408, filed 22 Sep. 2010. Priority of U.S. Provisional Patent Application Ser. No. 61/385,408, filed 22 Sep. 2010, incorporated herein by reference, is hereby claimed.
| Number | Date | Country | |
|---|---|---|---|
| 61385408 | Sep 2010 | US |
