PLATFORM DECK INSTALLATION AND REMOVAL METHOD AND APPARATUS
An apparatus for loading a topside onto a jacket is provided. The apparatus may include: a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure configured to support the topside and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and a support configured to support the topside above the projecting structure. A method for one of installing and removing a topside from a jacket may be provided. The method may include: positioning sponsons attached to a marine vessel around a jacket; supporting at least part of the weight of the topside on the sponsons; and one of attaching and detaching the topside and jacket.
The present invention relates generally to a method and apparatus for loading heavy offshore oiling equipment onto a submerged support such as a jacket. More particularly, the present invention relates to a method and apparatus for loading a topside onto and/or off a jacket.
BACKGROUND OF THE INVENTIONAs the demand for oil continues to increase, more and more oil fields are being identified as beneath the ocean floor. Traditionally, with offshore oil production platforms, either fixed or floaters, the topsides are installed to the substructures, jackets or hull, by a specially designed heavy lifting vessel such as a crane vessel. However, the use of heavy lifting vessels presents a variety of challenges including the reliability of being able to safely lift heavy structures, the availability of vessels capable of lifting required amounts of weight. Strict environmental requirements can create narrow weather windows in which operations may be done. High operational costs of using lifting vessels have encouraged the oil gas exploration and production industry to look for alternative ways to load heavy structures onto platforms.
For over the past several years, a technique referred to as the float-over topside installation technique has gradually gained momentum. It has not only been used in topside installation for fixed platforms already installed at the oil field, but has been used for floating support structures in both in-shore and offshore applications.
Float-over installation does not require the use of a heavy lifting vessel and therefore omits the challenging lifting operation. Only selected barges equipped with specially designed equipment are used in float-over operations. The technology is mature and the cost is relatively low compared to using heavy lifting vessels. Furthermore, float-over techniques can require shorter time and the weather window for performing such operations is wider than what is required in heavy lifting techniques.
However, the use of float-over technology is not without its drawbacks. Under current float-over techniques, when using a single barge or vessels for a fixed platform, there should be an opening wide enough between the legs of the jacket so that the barge carrying the topside can float in between the jacket legs. The barge will then move over and let the topside reach the position aligning with the jacket legs to prepare the jacket for the mating operating between the topside of the jacket. If there is not room for the barge to fit between the jacket legs, float-over operation can also be carried out using two barges where the barges are configured in a catamaran-type configuration. However, this is not favored for small platforms since the advantages of cost-efficiency disappear.
Many newer design jackets may have a wide opening between the jacket legs in order to accommodate the single barge float-over technique. However, many older jackets or ones that are traditionally designed may not have legs wide enough to accept the single barge. As such, they present additional difficulties in using a single barge or vessel with the float-over technique. Accordingly, it is desirable to provide a method and apparatus that can be used to more easily attach a topside to a similar structure such as a jacket.
SUMMARY OF THE INVENTIONThe foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus is provided that in some embodiments a method and apparatus is described that provides a new way to attach a topside to a substructure such as a jacket.
In accordance with one embodiment of the present invention, an apparatus for loading a topside onto a jacket is provided. The apparatus may include: a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure configured to support the topside and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and a support configured to support the topside above the projecting structure.
In accordance with another embodiment of the present invention, a method for one of installing and removing a topside from a jacket may be provided. The method may include: positioning sponsons attached to a marine vessel around a jacket; supporting at least part of the weight of the topside on the sponsons; and one of attaching and detaching the topside and jacket.
In accordance with yet another embodiment of the present invention, a method for one of installing and removing a topside from a jacket may be provided. The method may include: locating a support beam proximate to the jacket; moving the topside along the support beam; and one of attaching and detaching the topside and the jacket.
There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.
The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a method and apparatus for loading a topside onto a jacket or other similar structure and also unloading a topside from a jacket. In some embodiments, the installation and removal techniques may be used for fixed platform topsides weighing up to 4000 mt.
The apparatus and methods described herein fall primarily within two embodiments using skid-on techniques. In a first embodiment, a pair of skid beams are used to carry the topside over the jacket legs. In the other embodiments, sponsons are attached to a barge or other vessel and extend out of from the barge or vessel. In the embodiments, the skid beams or the sponsons carry the topside over the jacket legs. The mating process of the topside to the jacket legs is similar to that used in the known float-over at site techniques.
In the reverse process, in accordance with an embodiment of the invention, the skid-on technology can be applied to the topside removal. After reading the disclosure made herein one of ordinary skill in the art can using a case-by-case basis and examining the different facts of each particular application may be selected from one of the two options, the skid beam or the sponsons to attach or detach a topside and jacket. Skid beam techniques and sponsons techniques will be described below.
As shown in
The supporting frame 46 may be topped with a skid beam 48. The skid beam 48 may be an elongated structure or assembly rather than a single beam that extends out beyond the barge 44. A skid shoe 50 is mounted to the top of the skid beam 48. The topside 32 is attached to the skid shoe 50. The skid shoe 50 is configured to skid along the skid beam 48 thus enabling the topside 32 to move along the skid beam 48. A cable winch and pulley system 51 may be attached to the barge 44 and the topside 32 and may be configured to move the topside 32 on the skid shoe 50 along the skid beam 48 in a desired manner Other systems may also be used to move the topside 32 along the skid beam 48.
Once the barge 44 is positioned and is at a desired location with the respect to the jacket 34, the topside 32 may be moved via the cable winch and pulley system 51 along the skid beam 48 extending over the jacket 34. The barge or vessel 44 may be ballasted to move up or down in the water 54 in order to provide a desired vertical location of the topside 32. When the top side 32 is positioned over the jacket 34, the vessel 44 is high in the water to allow the topside 32 to be moved in position. The vessel 44 may then be ballasted to ride lower in the water 54 so that the topside 32 touches the jacket legs 36 enabling the topside 32 to be attached to the legs 36 according to well-known techniques similar to those used in float-over techniques.
In some embodiments, the technique of using mating cones and cups will be employed to assist in the connecting of the connecting structure 42 of the topside 32 and the legs 36 of the jacket 34.
Once the topside 32 is attached to the jacket 34 the finished structure 52 is formed as seen for example in
In some embodiments in accordance with the invention and as shown in
As shown in
As shown in
At this point, the barge or vessel 44 may be ballasted to ride high in the water 54. The skid shoe 50 and topside 32 are located over the supporting frame 46. The topside 32 may be moved along the skid beam 48 by use of a cable winch and pulley system 51 (see
Once the topside 32 is connected to the legs 36 of the jacket 34, the skid shoes 50 are detached with the topside 32 through mechanical action or ballasting the vessel 44 and the vessel 44 along with the supporting frame 46, the skid beam 48, and the skid shoe 50 may move away from the resultant finished structure 52 as shown in
The supporting frame 46 is attached to and rests upon the sponsons 62. The topside 32 has been positioned over the jacket 34. In some embodiments, the longitudinal dimension of the jacket 34 is near 40 meters near the water surface elevation. Each sponson 62 can be 80 meters long with 40 meters extending from the hull stern of the vessel 44.
The sponsons 62 may provide buoyancy to make the deck weight load better distributed on the barge hull. If more buoyancy is desired, the sponsons 62 may also include buoyancy boxes 64 which increase the buoyancy and therefore lifting capability of the sponsons 62. Buoyancy boxes 64 may be desirable particularly in instances where the topside 32 is particularly heavy.
One of ordinary skill in art may, after review of this disclosure, select an appropriate amount or size of buoyancy boxes 64 to attach to the sponson 62 as needed in individual applications.
As shown in
The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.
Claims
1. An apparatus for loading a topside onto a jacket comprising:
- a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure is configured to support the topside in a cantilevered manner and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and
- a support configured to support the topside above the projecting structure.
2. The apparatus of claim 1, wherein the projecting structure includes a support beam located above the deck of the marine vessel.
3. The apparatus of claim 2, wherein the support includes a skid shoe located on the support beam wherein the skid shoe is configured to skid across the support beam while supporting the topside thereby allowing the topside to move along the support beam.
4. The apparatus of claim 3, further comprising a winch system located on the marine vessel configured to move the topside along the support beam.
5. The apparatus of claim 2, further comprising a second marine vessel and a support column attached to the second marine vessel and the support beam whereby allowing the topside on the support beam to be supported by both marine vessels.
6. An apparatus for loading a topside onto a jacket comprising:
- a projecting structure extending beyond a deck of a marine vessel wherein the projecting structure is configured to support the topside and the projecting structure is dimensioned sufficiently long enough to allow the marine vessel to approach a submerged jacket and position the topside above the submerged jacket without having the marine vessel contact the jacket; and
- a support configured to support the topside above the projecting structure wherein the projecting structure includes a sponson attached to the marine vessel and providing buovancey to the marine vessel.
7. The apparatus of claim 6, wherein the support includes a jack attached to the sponson and configured to be actuated to move the topside vertically with respect to the sponson.
8. The apparatus of claim 6, wherein the sponson is a first sponson and further comprising a second sponson attached to the marine vessel and oriented alongside the first sponson and the topside is supported by both sponsons.
9. The apparatus of claim 6, further comprising a buoyancy box attached to the sponson and configured to provide additional buoyancy to the sponson.
10. A method for one of installing and removing a topside from a jacket comprising:
- locating a cantilevered support beam proximate to the jacket;
- moving the topside along the support beam; and
- one of attaching and detaching the topside and the jacket.
11. The method of claim 10, further including using a skid shoe to move the topside along the support beam.
12. The method of claim 11, further including loading a support assembly on a marine vessel, loading the topside onto the support assembly and fastening the topside and support assembly to the marine vessel.
13. The method of claim 11, further comprising ballasting a marine vessel supporting the support beam and adjusting the ballasting of the marine vessel as the topside is one of loaded and unloaded from the marine vessel.
14. The method of claim 11, further comprising supporting the support beam with a second marine vessel.
15. A method for one of installing and removing a topside from a jacket comprising:
- positioning sponsons attached to a marine vessel around a jacket;
- supporting at least part of the weight of the topside on the sponsons; and
- one of attaching and detaching the topside and jacket.
16. The method of claim 15, further comprising aligning the topside with the jacket and lowering the jacket to attach the jacket to the topside,
17. The method of claim 15, further comprising ballasting the marine vessel supporting the support beam and adjusting the ballasting of the marine vessel as the topside is one of on loaded and off loaded from the marine vessel.
18. The method of claim 15, further comprising raising the topside with respect to the sponsons.
19. The method of claim 15, further comprising providing buoyancy to the sponsons with a buoyancy box.
20. The method of claim 15, further comprising one of either attaching and reattaching the sponsons to the topside.
Type: Application
Filed: Sep 7, 2012
Publication Date: Mar 13, 2014
Applicant: Boa Marine Services, Inc. (Houston, TX)
Inventors: Gengshen LIU (Houston, TX), Helge Roraas (Houston, TX)
Application Number: 13/606,620
International Classification: E02B 17/08 (20060101); E02B 17/04 (20060101);