NO20220294A1

NO20220294A1 -

Info

Publication number: NO20220294A1
Application number: NO20220294A
Authority: NO
Priority date: 2022-03-09
Filing date: 2022-03-09
Publication date: 2023-08-14
Also published as: GB2616487B; GB202212295D0; NO347251B1; GB2616487A

Description

This invention can, but not necessary, be related to systems for (approximate) CO2 free offshore electric power generation, in the context of offshore oil and gas production, with i. e. external (exogenous) variable power supply in the form of wind turbines, solar power, tidal turbines, wave buoys and the like, in combination with variable internal (endogenous) electric power source(s). Electric power can be both imported or exported to and from the power system or installation(s). Fume gases can be injected into aquifer(s) or reservoir(s). AI brain, as part of an advanced control systems, can be implemented and utilized. Both the external and/or the internal electric power sources can represent residual or balancing electric power supplies. In the simplest form the residual internal electrical power supply is provided by at least one gas engine or a gas engine in combination with a turbine, with atmospheric fume release.

Background and definitions

Offshore hydrocarbon (HC) producing installations (platforms) have traditionally been powered by gas turbines, which subsequently drive generators for local electric power generation and consumptions.

Due to the aim of reducing CO2 emissions, HC installations or offshore field(s), constituting several installations, have been installed with onshore (mainland connected) power cables, enabling the offshore installations to be connected to an onshore power grid, providing fully or partial supply of onshore generated electric power. The transmitted power through (sea) cable(s) can be both in the form of adjustable current (AC) or direct current (DC). See e.g. (related to Johan Sverdrup and the Goliat fields):

https://www.equinor.com/no/what-we-do/electrification.html, https://www.eni.com/en-IT/operations/norway-goliat.html

As alternative electric power sources for offshore installations, offshore wind turbines, solar energy, tidal turbines, wave buoys and the like, have been proposed.

One example of such a system is the Hywind Tampen project. Hywind Tampen represents 88 MW (11 x 8 MW) of floating wind turbines, constituting a wind farm, intended to provide electricity for the Snorre and Gullfaks offshore field operations in the Norwegian North Sea. (Offshore) wind turbines are a variable energy source, which on average (“over the year”) has a capacity utilization of approximately 35 %. For shorter periods of time the capacity utilization can be both significantly lower or higher than this number.

Since wind, solar, tidal or wave energies are technologies of variable output or production, they provide a limited amount or being a variable within a total dynamic electricity system, like offshore oil and gas operations, which require stable and predictable electric power supply. Variable energy sources may normally provide up to or less than 10 % of the total electricity demand within a grid, without prohibiting or endangering the load viability and the entire (offshore) operations (production of crude oil and gas) enabled by the electric power supply. See e.g. Understanding variable output characteristics of wind power: variability and predictability (wind-energy-the-facts.org)

The problem with e.g. the Hywind Tampen project is that wind power will represent a variable supply source between 0 and 50 %, may be higher, depending on how many platform or units of the Tampen area it will supply, or how many installations that will be part of the grid(s) or network. The sole electric power suppliers and current regulator(s) of the individual platforms constituting the Tampa area are, at the present, gas turbines. A variable load (electric demand) and a highly variable partial supply sources in the form of e.g. wind turbines, will require flexible residual supply and providing short-duration load or puls load control.

Combined Cycle (CC) power plants, uses combinations of (e.g.) gas turbines (or gas engines), furnace/heat exchangers and steam turbine(s) together, see e.g. https://www.ge.com/gaspower/products/hrsg for details. Gas turbines and CC units have technical constraints related to startup time, ramp rate (increase/decrease of velocity, power etc), and minimum load rate for maintaining hot conditions. Hot start conditions maintain temperature and pressure in the steam components of the CC, allowing rapid ramping of the gas turbine(s) component(s). The exhaust temperature of gas turbines can reach 600 <o>C (LM2500+, T = 518 <o>C, https://www.geaviation.com/marine/engines/military/lm2500-plus-engine) In CC units with a furnace, temperatures can be more than 1200 <o>C. Hard ramp up rate and cycling can cause thermo-mechanical stress of the various components of the power plant beyond tolerance limits and provide human, technical, and economic hazards.

E. g. Wärtsilä (https://www.wartsila.com/energy/solutions/engine-power-plants/flexicycleand-chp/flexicycle-power-plants) has gas and fuel engines with lower exhaust temperatures, at 360 <o>C, also enabling lower steam temperatures, thus provide faster start up and ramping, without compromising units or components within the power plant [constituting e.g. gas turbines, furnace, heat recovery, steam turbine(s) and the like].

Other gas & dual fuel engines, see e.g.

https://www.siemens-energy.com/global/en/offerings/power-generation/rice.html

In this context a system is a group of interacting or interrelated elements or activities that act or interact according to a set of commands to form a unified whole. Such systems, surrounded and influenced by its environment, is defined or described by its boundaries.

Refining processes uses chemicals, catalysts, heat or pressure to separate and combine basic types of hydrocarbon molecules which naturally occurs in crude oils into groups of such molecules. Such groups are labeled petroleum components. Examples of such petroleum components are naphtha, kerosene, gas oil or distillates. Petroleum components are further processed to become refined products like gasoline(s), diesel, heating oils etc.

“Crude oil”, “petroleum components”, “refined products”, “non-refined petroleum” and “oil” are synonymous terms.

The term "gas" represents any combination of the gasses methane, ethane, propane, butane and the terms Natural Gas Liquids (NGL) and condensate. The concept "natural gas" is a mixture of methane and varying amounts of other higher alkanes. Condensate is NGL (Natural Gas Liquids) and hexane, heptane and octane. NGL is LPG (Liquid Petroleum Gas) and ethane and pentane. LPG is a mix of propane and butane. Natural gas can contain CO2, N2 and sulfide in addition to "gas". "Gas" and "natural gas" are synonymous terms.

Hydrocarbons (HC) can be any combinations of gas and (crude) oil.

The term “installation”, “platform”, “structure”, “units”, “source” are synonymous concepts. The term "offshore" represents any device, structure or installation located on, within or at the bottom (subsea) of water. Equivalently, "onshore" represents any device or structure located not on, within or under water (subsea).

The statement “at least one of” means, from a set of variables, activities or processes (synonymous terms) [a1, a2, …an] either a1, a2, …or an isolated (single activity) or any combination(s) among the variables. The term “at least one of” and “any combinations of” are synonymous.

The terms "fume gases", "flue gases", "gas mixture" and “CO2” are defined as synonymous terms. The terms "inject" and reinject" are synonymous terms.

“Grid” and “network” are synonymous terms.

“Puls”, “Demand” and “grid-balancing” are synonymous terms.

The term “External variable power source” or exogenous power supply represents at least one of wind turbines, solar power, tidal turbines, wave buoys and the like.

The term “Internal variable electric power source” or endogenous power supply represents at least one of gas engine, one gas turbine, one heat exchanger, one furnace, one steam turbine, Combined Cycle power plant and the like.

“Source” and “supply” are synonymous terms.

“Production” and “generation” are synonymous terms.

“Residual” represents a quantity of an element, e.g. Watt or kWh, remaining after other similar elements have been subtracted, allowed for or adjusted.

“Residual”, “balancing” and “rest” are synonymous terms.

“Power source” and energy source” are synonymous terms.

Prior art

The closed known prior art is NO 332044 (Myhr) which describes a system for integrated production of electric power from an offshore gas power plant with local gas production and reservoir injection of fume gases, and where the power is transported to consumers.

EP2795055 (Myhr) is related to integrated systems for offshore or land based industrial activities which use for feedstock or produce gas, crude oil and/or refined petroleum products/components, and provide reservoir injection of fume gases, can receive and store CO2 or flue gases from other offshore or onshore industrial processes or hydrocarbon producing installations, and can provide industrial products.

Some of the definitions used in this document follow what is stated in EP2795055.

WO2022003621A1 describes an offshore assembly to operate a facility, in particular an underwater oil and gas production facility, has: - a semi-submersible support structure arranged in a body of water and having at least one tubular portion; a wind turbine to generate electricity and equipped with a tower, a nacelle and a blade assembly; and at least one backup power source mounted on the semi-submersible support structure to generate electricity; a plurality of compartments stacked on top of each other within the tubular portion, in which each of the compartments is dedicated to housing respective equipment to perform respective functions; and a cooling and ventilation system to cool and ventilate said plurality of compartments.

DK202000220A1 describes an offshore jack-up installation that comprises a hull and a plurality of moveable legs engageable with the seafloor, wherein the offshore installation is arranged to move the legs with respect to the hull to position the hull out of the water when the legs engage the seafloor. The offshore jack-up installation also comprises an exhaust processing module arranged to receive exhaust gas comprising carbon dioxide. The exhaust module is arranged to process carbon dioxide in the exhaust gas and to output processed carbon dioxide to at least one other offshore installation for storage in a carbon dioxide storage pocket in the seabed.

Brief Summary of the Invention

The invention is a system for electric power generation in conjunction with at least one offshore installation (3) wherein the offshore installation comprises:

-at least one hydrocarbon production well on the seabed,

-means to control the flow of hydrocarbons from the at least one well,

-at least one riser structure for guiding hydrocarbons up to the at least one offshore installation,

the system for electric power generation comprises:

-at least one internal variable electric power source (6) wherein the at least one internal variable electric power source comprises at least one gas engine (11) driving at least one electrical generator, or at least one gas engine (11) and at least one gas turbine (12) driving at least one electrical generator, wherein Yadj(t) is the power output of the internal variable power source,

-at least one external variable electric power source (2) wherein said external variable electric power source is at least one of or a combination of a wind turbine, a solar power unit, a tidal turbine, or a wave buoy, wherein Xadj(t) is the power output of said external variable electric power source, wherein

-at least one control system (10) is arranged to monitor an electrical power demand D(t) (1) of said offshore installation and control a flow of electrical power between said one or more external power sources (2) and said offshore installation (3) as well as between said one or more external power sources (2) and an external grid, wherein said control system comprises a first independent controller for said internal variable electric power source (6) and a second independent controller for said one or more external variable electric power source (2).

Embodiments are defined in the attached dependent claims.

Embodiments of the Invention

The objective technical problem to be solved by the invention, is to manage an exogenous or external variable electric power supply, in the form of at least one wind turbine, solar power unit, tidal turbine, wave buoys and the like, and provide predictable and sustainable total electric power supply, enabling adequate and stable offshore oil and gas operations and subsequent production. This in combination with an internal or endogenous power source, where both the exogenous and/or endogenous power supplies can both represent residual power sources. In the most basic form, the residual (internal) electric power is supplied from at least one gas engine or the at least one gas engine and the at least one gas turbine with atmospheric fume release. A preferred solution is providing (residual) internal electric power in the context of (approximate) CO2 free offshore electric power generation, and subsequent oil and/or gas production.

All references, terms, definitions and phrases related to e.g. all major or minor units or subsystems mentioned in the "Background and definition", "Prior art", “Invention” sections and in the figures, also apply to, form the basis of, and are incorporated into the invention represented by this document.

Real-time control requires controllers to capture all the significant target activities and to deliver their responses as swiftly as possible so that system performance is never degraded.

In Advanced Industrial Control Technology, Peng Zhang, 2010, ISBN: 978-1-4377-7807-6, https://www.sciencedirect.com/book/9781437778076/advanced-industrial-controltechnology#book-info, structure and requirements to real-time control systems are outlined, excerpts (chapter 1.2.1, line 7):

“A control operation is a series of events or actions occurring within system hardware and software to give a specific result. A real-time control system is a system in which the correctness of a result depends not only on its logical correctness but also on the time interval in which the result is made available. The following three standards give the definition of a real-time control operation, and an industrial control system in which all the

control operations occur in real-time qualifies as a real-time control system:

(1) Reliable operation execution - the operation execution must be stable, and it must be repeatable.

(2) Determined operation deadline - any control operation needs time to execute.

(3) Predictable operation result -the result for any control operation must be predictable.”

Artificial intelligence (AI) technologies will advance or support the next generation of control systems.

Based on e.g. combinations of, but not limited to, Model Predictive Control, (MPC), Proportional Integral Derivative (PID), Deep Reinforcement Learning (DRL), three characteristics of AI-based controllers can be emphasized;

1. Learning: DRL-based controllers learn by methodically and continuously practicing (machine learning).

2. Delayed gratification: DRL-based controllers can learn to recognize sub-optimal behavior in the short term, which enables the optimization of gains in the long term.

3. Non-traditional input data: DRL-based controllers manage the intake and are able evaluate sensor information that automated systems cannot.

The enablement of e.g. DRL-based control systems to a process facility, require, but are not limited to, the following steps in delivering a DRL-based controls:

1. Preparation of a companion simulation model for the (AI) brain,

2. Design and training of the (AI) brain,

3. Assessment of the trained (AI) brain,

4. Deployment.

For further reading, see e.g. :https://www.controleng.com/articles/evolution-of-controlsystems-with-artificial-intelligence/

In this context the AI brain(s) is/are, but not limited to, to be trained to, at least one of; foresee, forecast, predict, simulate or otherwise, related to;

- wind status,

- weather status,

- supply of electric power from one or more wind turbines, wind park(s), solar power units, tidal turbines, wave buoys and the like,

- power demand from the platform(s) or offshore field(s) as part of the grid,

- supply and/or delivery status to any connected grid or electric power system connected by sea cable,

- technical and maintenance status to the various components constituting the installation and power system.

Advanced power-grid monitoring systems combine i.a. load-balancing, power-supply monitoring, metering functions, protection, supervision of power quality and disturbances, transient monitoring, and to enable efficient power delivery. For details, see e.g.: https://www.mouser.com/pdfdocs/Solar-Maxim-Power_Grid_Monitoring.pdf https://www.dnv.com/services/grid-code-compliance-measurements-72067https://www.dnv.com/services/grid-code-compliance-measurements-72067 https://www.vaisala.com/en/lp/leveraging-lidar-offshore-wind-energy? https://unipower.se/products-and-services/power-quality-management-system/pq-secure/

Several approaches have been proposed to extract (most of) the CO2 from the flue gas (mixture), named carbon capture (and storage) or CCS. The concept is to dispose only the fraction of the fume containing CO2 rather than the total flue volumes. This for practical and economic reasons. The various approaches can be labelled as post-combustion, oxy-fuel combustion or phase separation. The various techniques which can be utilized are among chemical (amine) solvents, physical solvents, physical absorbents, membrane separation processes, chemisorption, chemical bonding, phase separation.

For a more thorough discussion of various CCS approaches, see e.g.

http://gcep.stanford.edu/pdfs/assessments/carbon_capture_assessment.pdf

Detailed description of the embodiments of the invention

Figure 1 outlines the global architecture of the at least one electric power system. Power Demand (1) is measured from the total grid. The grid constitutes power demand from at least one offshore structure. The at least one wind turbine, tidal turbine, wave buoy, solar power unit and the like (2) provides external variable power supply (3). The at least one external power source can be located on the structure itself, on land, on or within water (offshore) and/or on separate structure(s). External power cable (4), if installed, can transmit electric power (5) both to and from the at least one installation. The at least one external power cable (4) can be mainland connected or represent alternative offshore grid structure(s). The residual internal power source (6) provides the residual internal power (7). The at least one processing unit (8), constituting at least one real time control system (10) and an AI brain (9), if installed. Generators are not shown. Any intermediate fume storage facilities are not shown.

The at least one such power unit (6) is either fixed (to the seabed) or locates on solid ground (onshore) or located on one or several fixed or floating (offshore) installations. Floating units can be founded on pontoons (semisubmersible), can be moored or anchored by tension legs. The unit (6) can be partly floating, can be mobile and/or can represent one or more vessels.

The installation or platform can be made of combinations of concrete, metals (steel), epoxy, kevlar, fibers, matrixes, synthetic materials, composites, fiber glass and the like.

As outlined in Figure 2, the internal power system (6) can constitute combinations of at least one gas engine (11), or the combination of a at least one gas engine (11) and at least one gas turbine (12). If a combined cycle power (CC) system is installed, the fume gas from the at least one gas engine (11), and/or the at least one gas turbine (12) can be fed to at least one heat exchanger and/or a furnace (13) to generate steam, which is powering the at least one steam turbine (14). At least one carbon capture unit (CCS) (15) can be part of the total system. At least one high performance (multiple) step compressor unit can be integrated within the system (16) to provide adequate pressure for the injection into wells on the sea floor where fume gases from at least one turbine unit is/are injected into at least one aquifer (17) and/or HC producing reservoir (17). All components of the system (11 – 17) are interconnected by the at least one processing unit (8), constituting at least one real time control system (10) and an AI brain (9), if installed.

At least one systemic control and guidance system (10) will interconnect all subsystems (1 -9), (11 – 17) with the help of sensors (not shown on figures). These sensors will, but are not limited to, the detection (quality and quantity to) pressure, temperature, heat (infrared), frequencies (sound, light), stress, strain, liquid (level), gas (concentrations), one or two phase fluid flows, relative and absolute humidity. Such sensors can be, but are not limited to, analog or digital electronic, electro - mechanical, optical or of ultrasound types. The sensors are connected by wire or wireless communications. Overall coordination of the control system is executed by at least one processing unit (8), which constitute the hub of the at least one control and guidance system (10).

Any storage facilities for gas and/or oil are not shown.

Units for separation of sand/and or water from gas and/or oil are not shown. The at least one electric generator is/are not shown. Any condensers are not shown.

The at least one gas turbine and/or gas engine, or any elements constituting a CC unit, if installed, can be fueled by any combinations of gas and oil, but preferably pure methane.

Parts of the electricity, or heat, or steam produced can be used to drift other parts of the installation [e.g. (15), (16)]. The control system (10) can be partially of totally overturned manually, meaning that at least one of the sub - systems or modules (1, 2, 6), (11 – 17) can be manually controlled.

The total system (6) can be fully or partly placed on the sea floor (subsea).

The system in which at least one gas engine (11) and/or gas turbine (12) unit or in a CC arrangement is/are combinations of gas turbine/engine and/or furnace/heat recovery steam generator (steam turbine) and the like, can be powered by any combinations of gas and oil. It is also possible that smaller amounts of sand and/or water is comprised in the terms "gas" and “oil”. Gas produced on the HC installation or within the field, is the preferred fuel.

The system (6) can be represented by components or subsystems (11 – 17) where these mainly comprise, but are not limited to, of combinations of metals, ceramics, composites, matrices, fiber, plastic, epoxy, kevlar, synthetic materials and the like. Use of concrete, wood, glass can be done where this appears as natural or beneficial, however this will not be chosen to a larger extent for load-carrying constructions.

The installation or field can be represented by, but not limited to, one or more global units or production units where the electric power production is driven by gas and/or oil to provide power supply to the at least one installation, and it also can produce oil and/or gas from at least one reservoir. This means that oil and gas can be produced from one or more reservoirs which are part of the field, and where (parts of) the gas can both be used for electricity production for export, and/or parts of the gas and the oil can be transported via buoy loading and/or by pipeline(s) away from the field. This is as an example.

The invention can comprise several separate power plants coupled together in parallel and/or in series, comprising one or more separate reservoirs for production of gas and/or reinjection of fume gases. This is as an example.

Case Studies

Split range control has been utilized for decades. A disadvantage of this control structure is that using a single controller, has i.a. limitations with respect to tuning.

A proposed Multiple Input Multiple Output (MIMO) model has been outlines for a system exemplified by figure 3. Major advantages of this (MIMO) approach, are that separate controllers for each input variable i.a. provide independent tuning and independent setpoints (SP) or target values for each of the variables.

In figure 4 Setpoint for the (PID) controller for the at least one external variable electric power source (e.g. wind turbines), applying Xadj (t) (Cx), is X(t) sp.

X(t) <sp >can be defined in various ways.

One dynamic example is to define X(t) <sp >= D(t), where D(t) = Demand, [f(t)], for electric power from the at least one offshore installation.]

This dynamic variable can be overturned by defining a static value, Xadj*.

Where Xadj<* >= nominal or target value for the at least one external variable electric power source.

Resulting in

Xadj (t) = adjusted input variable (output power), power supply from the at least one external variable electric power source.

The setpoint for the (PID) controller for the at least one internal variable electric power source (e.g. gas engine, gas turbine, CC unit, and the like), applying Yadj (t) (Cy), is X(t) <sp >+ Δ X <sp>.

Normally D(t) > Xadj(t), thus Δ X <sp >will have to be defined sufficiently to maintain normal operations of the at least one installation.

Where ei = exit or output index.

Equivalently, this can be overturned by defining a static value, Yadj*.

Where Yadj<* >= nominal or target value for the at least one internal variable electric power source.

Resulting in

Yadj (t) = adjusted input variable (output power) for the at least one internal variable electric power source.

Both Xadj (t) and/or Yadj (t) can be residual electric power supplies.

The model can be extended to multiple number of input variables.

The MIMO model is fully integrated with the processing unit (8), real time control system (10) and (AI) brain (9) of figures 1 and 2.

Examples

1. In one example the power output from e.g. a wind turbine park (at least one unit), S(t)<*>, partially or the total power, can be transmitted on and to a separate grid. This because a specific market is willing to provide a higher price when guaranteed that the power is exclusively based on wind energy (turbines).

2. If D(t) > Xadj (t), the power demand for the local grid is greater than what is provided by the variable external power source, e.g. a wind turbine park, the internal (residual) power, Yadj (t), Yadj (t) = D(t) - Xadj (t), if Si (t) = 0.

3. If D(t) > Xadj (t) Yadj (t), then Si (t) < 0, which implies the system has to import electric power from another grid.

4. If Yadj<* >is e. g. stated at max capacity and D(t) < Xadj (t) Yadj (t), then Si (t) > 0, and the excess power can be exported to an external grid.

Other features

a) Xadj (t) can be split between S(t)<* >and power to the installation(s), XSi (t).

b) Feedback sent to the controllers Cx and Cy independently can e.g. be provided by the control system (10) based on input from the AI brain (9). This would enable both Xadj (t) and/or Yadj (t) to be residual electric power supplies, concurrently or simultaneously.

The internal variable electric power source, i.e., at least one gas turbine and/or gas engine, is/are controlled to provide enough power to meet the demand of the offshore installation. The required power supply of the at least one gas turbine and/or gas engine Y(t)adj, is/are equal to D(t) - Xadj(t), where D(t) is the demand of the offshore installation(s) and Xadj(t) is the output of the (e.g.) wind turbine(s). That is, the at least one gas turbine and/or gas engine is/are controlled based on (a) how much the wind turbine(s) produce(s) and (b) the demand.

The wind turbine(s) is/are always on and generating as much power as possible. In one embodiment, the output of the wind turbine(s) Xadj(t) varies from 0 when the wind is 0 m/s and increases to a maximum value Xadj(t)(max) when the wind is 15m/s and remains at Xadj(t)(max) when the wind is between 15m/s and 25m/s. The values 15m/s and 25m/s are used as an example and these values could change based on the particular wind turbine(s) being used. In any case, the output of the wind turbine is varied according to the wind.

The system is controlled so that the system exports as much power as possible from the wind turbine(s), if a high price can be obtained for power generated by the wind turbine(s), and the system constitutes at least one external power cable (4). In that case, if the demand of the installation(s), D(t) is equal or less than the maximum output of the e.g. the at least one gas turbine and/or gas engine Yadj(t)(max), the e.g. at least one gas turbine and/or gas engine is/are controlled to power the installation and the power generated by the wind turbine(s) is/are exported to an external grid, i.e., export power = Xadj(t). If the demand of the installation is greater than the maximum output of the at least one gas turbine and/or gas engine Yadj(t)(max), the at least one gas turbine and/or gas engine is/are controlled to provide the maximum output and any excess power generated by the wind turbine is exported to an external grid, i.e., export power = S(t)<* >- Si(t) = Xadj(t) Yadj(t)(max) - D(t).

Thus, the controller Cy controls the internal variable electric power source based on the above specifications. The controller Cx controls the external variable electric power source for, i.e., manual overturning of the output of the wind turbine by additional pitching of the wind turbine blades, e.g. during very strong wind gusts or when there is an additional need for stabilize the electric supply to the offshore installation.

A most preferred solution for electric power generation on at least one offshore installation comprising at least one unit for separation of at least one of sand and water from gas and/or oil, and at least one hydrocarbon production well on the seabed, the control of hydrocarbons from the at least one well, at least one riser structure for guiding hydrocarbons up to the at least one installation, which system consisting of

- an internal variable electric power source including a gas engine and at least one generator;

- at least one external variable electric power source among wind turbines, solar power units, tidal turbines, wave buoys and the like,

- at least one control system for monitoring a demand of the at least one offshore installation, the control system including independent controllers for the internal variable electric power source and the at least one external variable electric power source.

Claims

PATENT CLAIMS

1. A system for electric power generation in conjunction with at least one offshore installation (3) wherein

the offshore installation comprises:

-at least one hydrocarbon production well on the seabed,

-means to control the flow of hydrocarbons from the at least one well,

the system for electric power generation comprises:

-at least one external variable electric power source (2) wherein said external variable electric power source is at least one of or a combination of a wind turbine, a solar power unit, a tidal turbine, or a wave buoy, wherein Xadj(t) is the power output of said external variable electric power source,

characterized by

2. The system for electric power generation according to claim 1, wherein

said system is arranged to export power to an external grid (4), wherein said system is further arranged to provide electric power generated by said at least one external variable electric power source (2) to said external grid (4).

3. The system for electric power generation according to claim 2, wherein

-said system is arranged to monitor a unit price of exported electric power and a unit cost of electric power produced by the internal variable electric power source (6),

-if said price of exported electric power is greater than said cost of electric power produced by the internal variable electric power source (6), then export all available power from the at least one external variable electric power source (2) to the external grid (4).

4. The system for electric power generation according to claim 2, wherein

if the electrical power demand (1) of the offshore installation is less than the electrical power producing capacity of the internal variable power source (6):

-the system is arranged to export all available power from the at least one external variable electric power source (2) to the external grid (4),

-the internal variable power source (6) is arranged to supply the offshore installation with electrical power.

5. The system for electric power generation according to claim 2, wherein

if the electrical power demand of the offshore installation is greater than the power production capacity of the internal electrical power source:

-the internal variable power source is arranged to produce its maximum power,

-the external variable power source is arranged to export the remaining of the offshore installation's electrical power demand to the offshore installation,

-the external variable power source is further arranged to export its excess electrical power to the external grid, wherein the excess electrical power is given as Xadj(t) Yadj(t) - D(t).

6. The system for electric power generation according to any of the preceding claims, wherein the at least one control system (10) comprises at least one AI brain (9).

7. The system for electric power generation according to claim 6,

wherein said AI brain (9) is trained to forecast power production of based on:

-wind status, weather status, supply of electric power from the external variable electric power source, supply to the external grid, and technical and maintenance status to components of the offshore installation and power system.

8. The system for electric power generation according to any of the preceding claims, wherein said at least one gas engine (11) and/or at least one gas turbine (12) are powered by any combinations of gas and oil.

9. The system for electric power generation according to any of the preceding claims, wherein said at least one internal variable electric power source (6) comprises at least one steam turbine (14) driving at least one electrical generator, said steam turbine (14) powered directly or indirectly by any combinations of gas and oil.

10. The system for electric power generation according to any of the preceding claims, wherein said power output Xadj (t) and/or said power output Yadj (t) can be residual electric power supplies, concurrently.