Patent Application
20250179986
The present application claims the benefit of Brazilian Patent Application No. BR1020230253725, filed Dec. 3, 2023, the entire contents of which are fully incorporated herein by reference.
The present invention falls within the field of technologies applicable to inspection and monitoring of the vicinity of floating platforms, specifically with regard to ways of electrically powering inspection and monitoring systems.
In recent years, the oil and gas exploration industry has faced a considerable challenge in the search for efficient inspection and monitoring solutions on floating platforms. The riser region of these platforms is critical, requiring the detection of problems such as broken wire and flooded annulus, among others. For the installation of permanent inspection and monitoring equipment in this area, a reliable and continuous power source becomes essential. In this context, a notable innovation is the present subsea system for capturing energy on floating platforms, a solution that takes advantage of the characteristics of the marine environment to generate energy and meet the energy needs of this equipment on site.
Currently, to power the measuring equipment located in the riser region, the power source generally comes from the platform itself. However, this implies modifications to the surface unit (topside) and, in many cases, requires running cables through the I-Tube area, an area that is difficult to inspect and maintain. Alternatively, some solutions use batteries integrated into the sensors, which in turn results in periodic replacement of these batteries.
Especially in cases where the electrical power comes from the platform, diving may be necessary to integrate the equipment into the circuit that passes through the I-Tube, increasing the risk and associated costs.
The proposed solution for this challenging scenario, as described in the present invention, consists of using the vertical movement of the platform, known as heave, to generate energy. Riser heave refers to the upward and downward vertical movement that risers, which are pipes or ducts that connect a floating platform (such as an oil or gas platform) to the seabed, experience due to waves and the action of ocean currents. Riser heave can actually be caused by the action of waves, ocean currents and other environmental factors. In this sense, the present invention describes a system whose operation involves energy capture units coupled to the risers, which convert the movement of the platform into electricity to power the inspection and monitoring equipment installed near the risers. This approach eliminates the need for modifications to the surface unit (topside) and the eventual demand for diving, in addition to increasing the autonomy of such equipment.
One of the crucial advantages of this innovation is that interventions can be carried out by Remotely Operated Vehicles (ROV), a resource already widely used in the industry for inspection and maintenance tasks. In addition, the installation of the subsea system modules for energy capture can also be performed by ROV, reducing the need for complex and expensive diving operations.
The proposed solution stands out for its efficiency and long-term savings. Generating electricity from the vertical movement of the platform provides a reliable source of energy to power the measuring equipment. In addition, this local generation eliminates the need for costly modifications to the surface unit, as well as periodic battery replacement, considerably reducing operating costs.
This approach aims to meet specific inspection and monitoring applications in the vicinity of floating platforms, providing energy in the order of hundreds of Watts, which is suitable for powering measuring equipment.
In summary, the subsea system for capturing energy on floating platforms represents a significant innovation in the oil and gas industry, addressing current challenges in an effective, economical and environmentally friendly way. By using energy from the subsea environment, this solution offers energy autonomy and reduces the need for complex interventions, becoming an attractive alternative for powering measuring equipment on floating platforms, with long-term benefits in terms of economy and sustainability.
Currently, in the state of the art, some systems are available for capturing energy on site in maritime regions, however, all of them have significant differences from the proposal of the invention. For example, there is no system in the state of the art that can be installed in pipelines or risers that are already in operation. In addition, the state of the art lacks systems that efficiently serve deep waters, and are also resistant to incrustations.
Below, some available publications of the state of the art of the present invention are shown, together with comparative comments with the technique described and claimed herein.
The document BR 112016008995 B1 describes a method and an apparatus for generating electrical energy. The method includes the steps of rotating turbine blades of at least one turbine, provided in a region of a submarine or umbilical tube through a respective movement of seawater, through a swept area associated with the turbine blades, and generating electrical energy in response to the rotation of the turbine blades.
An analysis of this publication BR 112016008995 B1 allows us to observe that its technology neglects important topics, such as detailing the installation and intervention mechanisms, operating depth (water depth) and hydrostatics.
Furthermore, in relation to the construction aspects, the type of encapsulation of the “[069] additional parts of the turbine” (see
Furthermore, it should be noted that BR 112016008995 B1 is not suitable for deep waters, since the transmission of movement from the turbine to the generator occurs exclusively via a rotating shaft (see paragraphs and of its publication), which makes it very difficult to ensure watertightness (or mechanical sealing), preventing water from entering the environment where the “[069] additional parts of the turbine” are contained, unless they can operate with compensated internal pressure, which is not mentioned in the document.
It should also be noted that BR 112016008995 B1 is quite sensitive to organic incrustations (which quickly deposit in the pipes in shallow waters), which will grow in the section of the pipe that is inside the “[067] turbine blades”, obstructing the passage of water flow and even blocking the rotation of the blades.
Finally, it is perfectly noteworthy that BR 112016008995 B1 has low energy capture efficiency, since the duct passes inside the blades, obstructing a large part of the water flow, in addition to there being no openings/slits between the blades, in the blade support, to drain the water deflected (upwards or downwards, depending on the direction of rotation) by the blades. This may imply prohibitive dimensions to meet the demand for underwater loads.
Compared to BR 112016008995 B1, the present invention provides a more robust and more specific technology for installation and operation in an underwater environment. Its topology is modular, composed of up to four power generation modules, and can be easily adapted to different loads. Its insertion and removal can be done in already installed ducts, since the tool support is composed of a split ring, installed by an ROV, where the generation modules are attached by quick coupling.
Furthermore, the present invention is resistant to scaling, since materials that delay such phenomenon are chosen. As for scaling that occurs in the pipeline, unlike BR 112016008995 B1, such scaling does not affect the movement of the articulated vanes used in the present invention.
The present invention can also be easily installed in deep waters, when using a hydraulic transmission system, where the vanes move a piston that pressurizes the hydraulic fluid inside a cylinder, or a linear generator can be used (instead of the synchronous generator), thus reducing the number of moving parts and increasing the reliability of the invention.
Finally, the present invention shows greater efficiency in energy capture than the state of the art, since it has better interaction with the mass of moving water, since nothing restricts the drag that the water flow causes on the articulated vane used in the described system, the coupling being direct and the stronger the larger the contact area of the vane.
In this sense, the present invention goes far beyond what is available in the state of the art, especially:
The present invention describes a system for generating energy that takes advantage of the heave motion (vertical upward and downward movement) of risers on floating platforms. This system consists of a set of split belts that contain capture and conversion modules fixed to them and an electric storage module. Each capture and conversion module is composed of an articulated vane structure, a movement conversion unit, an electric generator, a protective housing and a metal chassis.
The electric storage module is unique in the system. All capture and conversion modules are connected to the same electric storage module, which coordinates them.
The articulated vane interacts with the movement of the sea, converting this movement into a mechanical movement that is then transferred to the motion conversion unit. This unit converts the mechanical movement into rotational energy, driving the electric generator to produce electricity.
The electrical energy generated is stored in electrical accumulators, such as lithium batteries or supercapacitors, and controlled by a control unit. This control unit regulates the storage and supply of energy to consumers based on demand, the charge level of the accumulators and the available energy generated by the movement of the articulated blades.
The present invention proposes a system for generating energy from the heave motion of risers on floating platforms. Riser heave refers to the upward and downward vertical movement that risers, which are pipes or ducts that connect a floating platform (such as an oil or gas platform) to the seabed, experience due to waves and the action of ocean currents. Riser heave can be caused by the action of waves, ocean currents and other environmental factors. This movement is an important consideration in the design and operation of subsea systems, as it affects the integrity and efficiency of the risers. Therefore, the heave of the risers must be carefully taken into consideration when developing solutions for energy capture or any other application in the riser region of floating platforms.
In its turn,
In the capture and conversion modules, the articulated vanes (10) have a physical structure similar to an oar, the shovel (1), with a large contact surface that interacts with the seawater as the floating platform heave motion occurs as a result of the action of the waves.
This movement causes drag on the articulated vane due to its large contact surface. Meanwhile, the rigid rod (1.1) is screwed with freedom of rotation to a fastening device in the metal chassis (1.2), which in its turn is fixed to the metal belts (1.3) by means of a quick-coupling mechanism. The chassis is fixed to both belts to ensure good anchoring of the system in the riser.
In
In view of the definitions shown above, it can be understood that the system of the invention is fixed to a riser. Thus, there is no relative movement between them, except for the articulated blade (10) that interacts with the seawater as the floating platform heaves upward and downward. This heave motion causes drag on the articulated blade (10) due to its large contact surface.
The energy extracted from the flow during the movement of the articulated blade (10) is converted into rotation to actuate the electric generator (3) by the motion conversion unit (20), this motion conversion unit (20) being made up of a set of gears or a hydraulic system.
In this sense, as an option to the use of a hydraulic system in the motion conversion unit (20) at great depths, said motion conversion unit (20) can be configured by gears, being the preferred modality for use at shallower depths. The articulated vane (10), in this embodiment, is interconnected to a rack (1.4) which, meshed with a pinion, converts the reciprocating movement into rotary motion, in which the rotation is adjusted to the nominal value of the electric generator (3) by a suitable gear ratio. A double ratchet and floating gear assembly, in an exemplary embodiment, can be used to enable the use of both upward and downward movements of the articulated vane (10), driving the electric generator (3) in the same direction.
The electric storage module (40) is composed of lithium batteries or supercapacitors (electric storage modules (50)), with the capacity to store energy. To control the charging regime of the electric storage module (40) and the supply of energy to the consumer(s), the use of a control unit (60) is programmed, which is composed of measurement and control subsystems and a static converter (power electronics). The static converter extracts power from the electric generator (30) and transfers it to the electric accumulators (50). This conversion rate is estimated by a controller that, based on the amount of energy available in the movement of the articulated vane (10), the charge level of the electric accumulators (50) and the demand of the consumer(s), calculates the optimal setpoint for the converter.
In this way, the load unit (40) coordinates the operation of the entire electric accumulator module with the sole purpose of instantly delivering the energy demanded by the consumer(s). The system components are sized to meet the needs of consumers within a certain operating regime. This energy must be supplied by the electric accumulators, which are continuously recharged by the control unit (60) by extracting energy from the heave motion of the articulated vanes (10).
In this preferred embodiment of the invention, the pair of motion conversion unit (20) plus electric generator (30) is dimensioned in modules of up to 25 W, and there may be up to four modules in parallel per system. In this sense, the electric accumulator (50) will be dimensioned to supply up to 1200 Wh at 24 Volts.
The solution described by the present invention therefore comprises a system that can be applied to the risers of floating platforms to supply power to tools installed nearby for inspection and/or monitoring. For example, the system proposed herein is capable of being a power source for inspection and/or monitoring in the region of the risers of floating platforms, such as detecting broken wire, flooded annulus, etc. The invention may be integrated into the measurement tool or be installed separately by remotely operated vehicles (ROV). Its concept is modular, allowing it to cover a wide power range and can be replicated in several sets along the riser. The technology can be applied in shallow waters (up to 50 m) or deep waters (up to 3000 m) by adapting the use of hydraulic means or gears described above, designed in the generating units to reduce the riser movement with depth. These changes include, precisely, the use of articulated vanes (10) with a larger area and a motion conversion unit (20) providing hydraulic cylinders with a larger diameter or a different gear ratio to maintain the rotation generated due to the smaller amplitude of the expected heave motion. At greater depths, preference is given to hydraulic motion conversion units (20) because they simplify the seals to be used in the coupling with the electric generator (30). The motion conversion unit (20) by gears is preferably used at shallower depths (up to 50 m). The motion conversion unit comprises a piston connected to the articulated vane (10), which accesses a hydraulic cylinder pressurizing a fluid that moves a mini hydraulic turbine (or hydraulic motor) a gearbox (2) and that converts the linear motion of the piston into rotary motion, actuating the electric generator (3).
The present invention is described herein in terms of its preferred embodiment. A person skilled in the art in possession of the information described herein is perfectly capable of observing that changes can be made based on the present description, such changes still being included within the described and claimed scope.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1020230253725 | Dec 2023 | BR | national |
