Hydraulic and earth engineering – Marine structure or fabrication thereof – Floatable to site and supported by marine floor
Patent
1987-11-02
1989-11-28
Taylor, Dennis L.
Hydraulic and earth engineering
Marine structure or fabrication thereof
Floatable to site and supported by marine floor
405195, 405203, E02B 1708
Patent
active
048833894
DESCRIPTION:
BRIEF SUMMARY
The present invention relates to a method for constructing and assembling huge modules, and in particular steel trusswork modules for oil rigs operating at sea, and a module fabricated by said method. The completed module is defined by a surrounding module frame comprising truss frames for side walls and a roof, as well as one or more deck structures located within and fixed to the module frame.
In the past, construction of huge steel modules has been limited, inter alia, by technical conditions, as limitations in the lifting capacity in the constructing yards, and limitations in the lifting capacity on crane barges for lifting the completed modules at sea. The typical lifting capacity in larger Norwegian yards is 200-300 tons. Special equipment may, however, be provided for particularly heavy lifting operations, in the form of mobile cranes, floating cranes, or encompassing lifting mast systems. For lifting completed modules at sea, the limitation has been approximately 3000-4000 tons, thus limiting the module weight to approximately 2500-3000 tons.
Thus, constructing modules in the traditional way is limited by the lifting equipment. This, indeed, also goes for the constructing sequence and degree of completion of prefabricated deck structures and module members.
The modules have huge dimensions, and may have a width of more than 20 meters, and a length of 50 meters or more. Previously, module weights have not exceeded 2500 tons.
The constructing technique commonly used has been some kind of prefabrication of trusswork structures in the form of truss frames. Initially, such a frame is erected and constitutes a central vertical frame in the completed module. A lower deck half is then mounted onto the central frame, and a second deck half is mounted onto the other side of the central frame. Thereafter, auxiliary supports are erected at each corner of the lower deck, and one or more auxiliary supports are erected as well between each corner to support the next deck half which is, in turn, mounted onto the central frame. A corresponding deck half is mounted onto the other side of the central frame. Another set of auxiliary supports is erected and placed on the latter deck, whereafter another deck half is provided on the supports and is fixed to the central frame. In this manner, the module is assembled until the predetermined number of deck structures has been mounted. Finally, the prefabricated truss structures that will form side walls are erected and secured to the deck edges, and the auxiliary supports can be removed. Thus, the completed module is comprised of trusswork frames in the side walls and the central wall, and any desired number of deck structures. Installation of equipment, including pipeworks and cableworks may be carried out during deck construction.
The developing trend seems to be that lifting capacity at sea will increase to approximately 12000 tons. This is reflected by the interest of oil companies in constructing larger and more complete modules on shore, which will provide time savings, weight savings, and be less expensive. There is reason to believe that module weights of future oil rigs will be between 4000 and 10000 tons.
There exists a demand from oil companies for constantly decreasing total project time. This means a reduced period of time from the decision that an oil field is to be developed until production is a fact. There is also a need to reduce the steel weights on the rings, i.e. a desire for low specific weight of the modules. Furthermore, a high degree of prefabrication on shore would be advantageous, i.e. low requirement for completion at sea. All demands are based on the desire for reduced developing costs.
As to the demands of the companies, the desire to be competitive as regards prices, i.e. high productivity, is decisive. There is a demand for good utilization of the production facilities, i.e. for short throughput at the yard, and optimal utilization of equipment and staff. Furthermore, it is desireable to find a design and constructing methods furthering produ
REFERENCES:
patent: 4488 (1988-07-01), Rowan
patent: 3012406 (1961-12-01), Lassen-Nielsen
patent: 3466878 (1969-09-01), Esquillan et al.
patent: 3722169 (1973-03-01), Boehmig
patent: 3927535 (1975-12-01), Giblon
patent: 3974618 (1976-08-01), Cortina
patent: 4006567 (1977-02-01), Flannery
patent: 4227831 (1980-10-01), Evans
patent: 4448570 (1984-05-01), Berthin
patent: 4493591 (1985-01-01), Francis, Jr.
patent: 4636113 (1987-01-01), Terai
Haugesund Mekaniske Verksted A/S
McBee J. Russell
Taylor Dennis L.
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