EP2409910A2

EP2409910A2 - Semi-submersible floating platform with hydraulics and independent propulsion

Info

Publication number: EP2409910A2
Application number: EP11398005A
Authority: EP
Inventors: Joâo Manuel Machado Pinto Germano; Filipe Manuel Pereira Antunes
Original assignee: Germano Joao Manuel Machado Pinto
Current assignee: Germano Joao Manuel Machado Pinto
Priority date: 2010-07-19
Filing date: 2011-07-19
Publication date: 2012-01-25
Also published as: EP2409910A3; PT105206B; PT105206A

Abstract

The invention seeks to solve the mobility problem associated with semi-submersible floating platforms. The invention aims to enable the semi-submersible floating structures alternating between a static and a floating position, which allows independent propulsion through a self-propelled system. The hydraulics of the structure is used to collect the submersible structure that is submerged in the water, passing the structure to a floating position with a self-propelled system.

The invention comprises a rigid flat platform of operation (4) with two keels float (5) located under this platform. Between these keels lies a structure composed of four main columns (1) with hydraulics, four circular flooding tanks (8) and a secondary structure in the form of vertical truss (3) and horizontal (2), being the vertical truss (3) equipped with hydraulics. The invention combines stable conditions of usage on floating marine environments necessary for the proper development of services.

Description

Technical domain of the invention

The present invention relates to the support structure of semi-submersible floating platforms designed to marine environments. The invention is related to the structure of this type, semi-submersible platform that has hydraulics support structure placed in the bottom that allows you to switch between static and floating positions, gathering and stretching the same, ensuring the stability of vertical and horizontal.

Prior Art

There are in use several types of offshore platforms that are classified according to their support structure. These platforms are classified as fixed or floating. Fixed platforms are platforms on which the support structure is founded on the sea floor by gravity or truss towers. The floating platforms are structures where the flat operative platform is situated above the water line, and this is connected by supporting columns to the lower structure.
The semi-submersible floating platforms fall on the floating structures mentioned. The platform submerged function in the marine environment is achieved by filling the tanks located in the lower support structure and columns of connection between the flat operative platform and support structure. This support structure and lower the columns that connect the flat operative platform are rigid and fixed, and its position secured through dynamic positioning systems.
These structures have a high stability allowing a very stable horizontal float.

Description of figures

Fig. 1 - Figure 1 shows a perspective view of the invention, i.e., the semi-submersible floating in its static position or elongated.
The invention, as illustrated in Figure 1, consists of a rigid flat operative platform (4), supported by a semi-submersible lower support structure that consists of four main columns (1) that work with hydraulics that allow switching between a position more elongated and static and a reduced and floating position.
The lower support structure comprises a vertical truss structure (3) and horizontal (2). The vertical truss structure (3) is equipped with hydraulics that allows monitoring of the stretching or recoiling movements of main columns (1). At the bottom of the four main columns (1) are four circular flooding tanks (8). Under the rigid flat operative platform (4) are two floating keels (5).
Fig. 2 - Figure 2 shows a perspective view of the invention, i.e., the semi-submersible floating in its floating position or recoiled.
The invention, as illustrated in Figure 2, consists of a rigid flat operative platform (4), supported by a semi-submersible support structure that consists of four main columns (1) that work with hydraulics that allow switching between a position more elongated and static and a reduced and floating position.
The lower support structure comprises a vertical truss structure (3) and horizontal (2). The vertical truss structure (3) is equipped with hydraulics that allows monitoring of the stretching or recoiling movements of main columns (1). At the bottom of the four main columns (1) are four circular flooding tanks (8).Under the rigid flat operative platform (4) are two floating keels (5) and an anti-wave support structure (6), composed of tubular metal elements, which is connected to the horizontal truss structure (2) and to the rigid flat operative platform (4).
Fig. 3 - Figure 3 shows a perspective view of the invention, i.e., the semi-submersible floating in its floating position or recoiled.
The invention, as illustrated in Figure 3, consists of a rigid flat operative platform (4), supported by a semi-submersible support structure that consists of four main columns (1) that work with hydraulics that allow switching between the position more elongated and static and a reduced and floating position.
Under the rigid flat operative platform (4), according to Figure 3, there are two floating keels (5). The invention has under the platform, an anti-wave protection structure (7) like a "blind", which protects the bottom of the submersible platform structure and is linked to this through an anti-wave support structure (6), composed of tubular metal elements.
Fig. 4 - Figure 4 shows a plan view from the top of the invention, i.e., the semi-submersible floating.
The invention, as illustrated in Figure 4, consists of a rigid flat operative platform (4) with a square geometry.
Fig. 5- Figure 5 shows a plan view of the bottom of the invention, i.e., the semi-submersible floating in your static position or elongated.
The invention, as illustrated in Figure 5, consists of a rigid flat operative platform (4), supported by a semi-submersible support structure that consists of four main columns (1) that work with hydraulics that allow switching between the position more elongated and static and a reduced and floating position.
The lower support structure comprises a vertical truss structure (3) and horizontal (2). The vertical truss structure (3) is equipped with hydraulics that allows monitoring of the stretching or recoiling movements of main columns (1). Under the rigid flat operative platform of operation (4) are two floating keels (5). At the bottom of the main columns (1) are four circular flooding tanks (8).

Detailed description of the invention

The invention is a structure of semi-submersible floating platforms where the lower support structure, that is placed under the rigid flat operative platform is equipped with hydraulics that allows stretching or recoiling of this structure, which allows the semi-submersible platforms alternate between a static or stretched position and a recoiled position or floating. Additionally, the system includes a mobile anti-waves structure and a self-propulsion system of that will be used when the platform is in the recoiled position or floating.
The execution of the structure of semi-submersible floating platforms requires the consideration of the necessary requirements of buoyancy, positioning, stability, mobility and functionality. The requirements listed come from the fact that the function of the structure couldn't interfere with the security required and mandatory to structures in marine environments, since this structure can, for example, be used in partnership or in help to other structures that are located in the marine environments.
The structure of semi-submersible floating platform comprises a flat rigid operative platform, that is above the waterline, two floating keels in the bottom of the flat operative platform and a lower support structure which is composed of four main columns, four circular flooding tanks, a vertical and horizontal truss structure, an anti-waves structure and its supporting structure, as illustrated in Figures 1 and 3.
The rigid flat operative platform, as the name implies, is a flat and rigid structure that lies above the waterline of the marine environment where the structure is.
The platform provides physical support to the machinery and devices necessary for its operation, providing in its interior, space and area for its installation. That platform has, at its top, area for installation and operation of services whose diversity depends on the desired operation for the entire structure.
The floating keels are located under the rigid flat operative platform and they give support and buoyancy to the structure of semi-submersible platform when the lower support structure is fully recoiled. Thus, the structure will float on the floating keels in a process similar to a vessel, which they must be properly sealed.
The lower support structure is located under the rigid flat operative platform and its position is in an area between the two floating keels above mentioned. The main columns belonging to the lower support structure connect the platform to the rigid flat operative platform to the four circular flooding tanks located at the end of the main columns. These columns consist of hydraulic mechanisms that allow switching between a more elongated or recoiled position of the columns, according to the operation of a hydraulic cylinder. When the main columns are in its most elongated position, they guarantee structural stability of the entire platform.
The main columns are connected by a vertical truss structure and a horizontal truss structure. The vertical truss structure connects the vertical columns to the rigid flat operative platform. These have hydraulics that allows them to track the movement of recoiling or lengthening of the main columns. When the main columns are in its most elongated position, the vertical truss structure is also at its most elongated position, ensuring structural stability of the main columns even if they are subject to side effects of existing currents in the marine environment.
The horizontal truss structure, which connects the circular flooding tanks on the main columns, is a fixed and rigid structure, which tracks the movement of recoiling or stretching of the main columns and the vertical truss structure without changing its extension, since it is rigid. This structure ensures the verticality of the main columns, providing structural rigidity and strength when they are subject to action from the side effects caused by the chains present in marine environments.
When the columns are in their recoiled position, the structure of semi-submersible platform is in its floating position. At this stage, the main columns and the vertical truss structure is completely recoiled and near the bottom of the rigid flat operative platform. In the horizontal truss structure, is a support structure consisting of several metal tubular elements. These metallic elements connected to the tubular truss structure are the horizontal anti-wave support structure. The front and rear parts are supported by a structure comprised of tubular metal elements that are connected to the flat platform of operation for its rigid bottom.
The anti-wave protection is a structure that protects the whole lower structure of the semi-submersible platform. This anti-wave protection will only be used when the semi-submersible platform is in it's more recoiled or floating position. The anti-wave protection is composed of laminar rectangular elements that are connected to the horizontal truss structure by metal tubular elements protruding from underneath structure. The laminar rectangular elements which are linked by their support structure to the horizontal truss structure, perform a rotation of 90° around a central axis, located along the axis of those laminar rectangular elements, making a motion similar to a "blind". When the platform is in its more elongated position, the laminar rectangular elements have a vertical position which helps to stabilize the platform, functioning as rudders. When the platform is in it's most recoiled or floating position, laminar rectangular elements rotate around the axis, in sequence, assuming a horizontal position making a perfect fit between the laminar elements, constituting the flat part of the anti-wave structure of the bottom of the semi-submersible platform.
The front and rear parts of the anti-wave protection are linked to the rigid flat operative platform through its rigid support structure that performs a rotation movement around a point, making a motion like "fan" where the laminar elements are arranged in a movement like "blind".

Description of Method

The structure of the floating semi-submersible platform ensures buoyancy based on the Archimedes buoyancy principle, which formulated that when a body is dived in a liquid, it will shift a proportion of liquid equal to its volume, and the weight of that liquid volume is subtracted from the weight of the body by the force called impulse. Thus, the practice of monitoring the depth of such platforms has become possible and is used quite often.
The movement of recoiling and extension of the main columns and the vertical truss structure will be made by means of hydraulic mechanisms, by pressurizing the fluid contained within the hydraulic mechanisms, performing the stretching of hydraulic cylinders. The combination of pressurized liquid density inside the hydraulics and the flooding of the circular flooding tanks at the bottom of the main columns, allows monitoring of buoyancy and stability of the structure during the recoiling or stretching of the main columns and the vertical truss structure.
The lower structure of the semi-submersible floating platform is arranged to ensure the structural stability of the platform when it is in the most elongated position. At this stage, in which the semi-submersible platform is in its static position, it is necessary to ensure horizontal and vertical stability, since the structure is subject to the effect of existing currents in marine environments.
The arrangement of the lower structure of the semi-submersible platform was achieved in order to offer the least resistance to these maritime currents. When completed, the process of transition from the recoiled or floating position to an elongated or static position, the semi-submersible floating platform will get the water line of the marine environment halfway up the main columns, thus minimizing the movements of the rigid operative platform caused by the excitation of the waves. The stabilization of the position of semi-submersible floating platform when it is in its most elongated and static position, is achieved through a system currently in use so-called dynamic positioning system.
This system consists of a complex system of sensors that can be GPS, sonar, anemometers, or other, that measure the position and direction of the platform, sending information to a central processor responsible for executing the control algorithm. This processor automatically sends the information to control propellers or rudders which ensure the platform position. This system is widely used in various ways to navigate in marine environments. When the semi-submersible floating platform passes from is it's most elongated and static position to a recoiled or floating position, there is a reversal of the referred process, gathering the lower support structure of the platform, that consist of the main columns and the vertical truss structure and horizontal.
After gathering all the lower support structure, the semi-submersible platform can be seen floating on the two floating keels that stay under the rigid flat operative platform. In order to protect the lower support structure of the platform, the anti-waves protection is activated. The laminar rectangular elements that form the anti-waves protection are in their upright position and when the entire lower support structure of the platform is recoiled, they rotate around the axis that lies within. The movement ends when the rectangular laminar elements are in a horizontal position, making anti-waves protection platform. On the front and rear parts of this anti-waves protection, multiple rectangular laminar elements, supported by its supporting structure, will rotate around the connection point on the rigid flat operative platform.
In order to make a protection in a circular form, rectangular laminar elements "fall" of the rigid flat operative platform, disposing the protection elements in a movement such as "blind".
The platform gains this way, a new mobility while floating on those floating keels and self-propelled floating through the effect of suitable propellants.

Claims

- Support structure of semi-submersible floating platforms, aimed at the marine environment, with hydraulics placed in the lower support structure that allows switching between elongated and recoiled positions, is characterized by consisting of a rigid flat operative platform (4), two floating keels (5), four main columns (1), a vertical truss structure (3), a horizontal truss structure (2), an anti-wave support structure (6), an anti-wave protection (7) and four circular flooding tanks (8).
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having hydraulics mechanisms in the lower structure of the platform, to switch between static and most elongated position and a more recoiled and floating position.
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having four circular flooding tanks (8) in the main columns (1) with hydraulics.
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having floating keels (5) self-propelled.
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having an horizontal truss structure (2) in the rigid flat operative platform (4), an anti-wave support structure (6).
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having an anti-wave protection (7) under the lower support structure, which act as a rudder, providing the stability of the platform.
- Semi-submersible floating platform with hydraulics and autonomous movement characterized by, according to claim 1, having an anti-wave protection (7) under the rigid flat platform of operation.