Key information

Title: STEAM PRODUCTION SYSTEM, STEAM GENERATOR UNIT, RELATED APPARATUS AND METHODS
Application number: 20250248
Case type: National
Status: 06.03.2025 Andre og senere realitetsskriv foreligger
Filed: 06.03.2025
Effective date: 06.03.2025
Publicly available: 07.09.2026
Next annual fee due: 31.03.2027
Applicant: Scan Tech AS (NO)
Inventor: Andreas Fliss (NO) et al.
Agent: HÅMSØ PATENTBYRÅ AS (NO)

Abstract and drawing

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.

A steam production system for an EX Zone or Safe Zone of an oilfield exploration or production facility, a related steam generator, methods for producing steam and operating the system, and apparatus in the form of a unitary structure, are described. In various examples, the system is configured to be connected to facility water and facility electrical power. The steam generator unit can include a tank for containing water and steam, and at least one electrically operable heat source arranged to emit heat within the tank to generate steam from water contained therein. A pre-processing system may be included in the steam generating system and may include a preheater comprising at least one electrically operable heat source to pre-heat the water to be supplied to the steam generator.

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Date

Date	Doc. No.	Process	Case number	In/Out	Journal description	To/from
27.08.2026	07-05	Saksbehandling	20250248	INN	P31608NO00 Translated claims pages 35 to 40	HÅMSØ PATENTBYRÅ AS
27.08.2026	07-04	Saksbehandling	20250248	INN	P31608NO00 Letter to NIPO	HÅMSØ PATENTBYRÅ AS
27.08.2026	07-03	Saksbehandling	20250248	INN	P31608NO00 Amended specification pages 1 to 34	HÅMSØ PATENTBYRÅ AS
27.08.2026	07-02	Saksbehandling	20250248	INN	P31608NO00 Additional sheets mark-up	HÅMSØ PATENTBYRÅ AS
27.08.2026	07-01	Saksbehandling	20250248	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
29.05.2026	06-01	Saksbehandling	20250248	UT	Substantive Examination	HÅMSØ PATENTBYRÅ AS
27.03.2026	05-05	Saksbehandling	20250248	INN	P31608NO00 Replacement drawings sheets	HÅMSØ PATENTBYRÅ AS
27.03.2026	05-04	Saksbehandling	20250248	INN	P31608NO00 Letter to IPO	HÅMSØ PATENTBYRÅ AS
27.03.2026	05-03	Saksbehandling	20250248	INN	P31608NO00 Amended specification pages 1 to 32	HÅMSØ PATENTBYRÅ AS
27.03.2026	05-02	Saksbehandling	20250248	INN	P31608NO00 Additional sheets mark-up specification	HÅMSØ PATENTBYRÅ AS
27.03.2026	05-01	Saksbehandling	20250248	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS
06.10.2025	03-02	Saksbehandling	20250248	UT	PT report 11:20:30
06.10.2025	03-01	Saksbehandling	20250248	UT	Substantive examination	HÅMSØ PATENTBYRÅ AS
07.03.2025	02-01	Saksbehandling	20250248	UT	Informasjon til oppfinner	Andreas Fliss
06.03.2025	01-04	Saksbehandling	20250248	INN	Scan Tech AS POA	HÅMSØ PATENTBYRÅ AS
06.03.2025	01-03	Saksbehandling	20250248	INN	P31608NO00 Specification	HÅMSØ PATENTBYRÅ AS
06.03.2025	01-02	Saksbehandling	20250248	INN	P31608NO00 Drawings	HÅMSØ PATENTBYRÅ AS
06.03.2025	01-01	Saksbehandling	20250248	INN	Søknadsskjema Patent	HÅMSØ PATENTBYRÅ AS
	04-02	Saksbehandling	20250248	INN	Korrespondanse (Hovedbrev inn)	HÅMSØ PATENTBYRÅ AS

Description, claims and drawings

Disclaimer: This text has been machine-scanned and may contain errors – please refer to "Publications" for legally binding content.

Description

STEAM PRODUCTION SYSTEM, STEAM GENERATOR UNIT, RELATED APPARATUS AND METHODS.

Technical field

The present invention relates to the production of steam on an oilfield exploration or production facility, the steam for performing one or more steam tasks at the facility, and in particular it relates to a steam production system, a steam generator unit, related apparatus, a method of producing steam, and a method of operating the steam production system.

Background

Traditionally, diesel driven steam generators are used on offshore oil and gas facilities to produce steam for performing industrial tasks on the facility. These generators emit significant amounts of CO2 which is environmentally undesirable. Typically, one litre of diesel produces about 2.4 kg of CO2. Diesel engines require maintenance and people on site to work them. This can result in significant inconvenience and cost. They can pose safety risks and have limited efficiency. The inventors see a need for improved solutions for steam production on oil and gas exploration and production facilities, including for example on offshore platforms or rigs.

Summary

According to first aspect of the invention, there is provided a steam generator unit for an oilfield exploration or production facility, e.g. for a designated EX Zone or Safe Zone of an oilfield exploration or production facility, the steam generator unit configured to be connected to facility water and facility electrical power, the steam generator unit comprising: a containment structure to contain water and steam; at least one electrically operable heat source configured to be connected to a facility electrical power outlet, the heat source arranged to generate steam from contained water within the containment structure.

The heat source may be provided with an electrical connector for mating with a complementary facility power outlet electrical connector. In certain examples, the steam generator unit may be configured to be connected to three-phase electrical power and/or the heat source configured to be connected to a facility three-phase electrical outlet. In such examples, the facility power outlet electrical connector may be a three-phase power outlet electrical connector.

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The steam generator unit may have multi-voltage capability for allowing connection to facility power at different voltages and electrically operating the heat source with electrical power from an input supply at one voltage or another voltage. The heat source may have an operating power in the range of 50kW or greater, for example in the range of 50 to 500 kW.

The containment structure of the steam generator unit is typically a tank for containing water and steam therewithin. The containment structure, e.g. tank, may have a water supply inlet which may be openable/closable e.g. by a valve. The water inlet of the steam generator unit may be configured to be connected to one or more fluid flowlines for supplying water to the steam generator unit. The valve may be a flow valve of a flowline section connected to the water inlet for supply of water into the steam generator unit when the valve is open. The containment structure, e.g. tank, may have a water outlet which may be openable/closable, e.g. by a valve which may be a flow valve of a flowline section connected to the water outlet for communicating water away from the steam generator unit when the valve is open. The containment structure, e.g. tank, may have a steam outlet which may be openable/closable, e.g. by a valve which may be a flow valve of a flowline section connected to the steam outlet for communicating steam out of the steam generator unit when the valve is open.

Typically, the steam generator unit may have a control unit or device to control operation of the steam generator unit. The control unit or device may be arranged to control the heat source. The control unit or device may be configured to adjust the power of the heat source to vary the amount of heat energy emitted.

The control unit or device may be operable to control the heat source based on detected temperature of contents within the containment structure. The control unit or device may be operable to control the heat source based on detected pressure of contents within the containment structure. The control unit or device may be configured to open a valve to let water into the containment structure based upon any of: detected water level; detected temperature; detected pressure; amount of consumed steam.

The heat source may extend or protrude into a region within the containment structure. The heat source may thus be arranged to be immersed within water contained in the containment structure in use. The control unit or device may be configured to let water into the containment

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structure, e.g. by controlling and operating a valve to open the water supply inlet, such that water in the containment structure may be replenished and maintained with a water level above the heat source therein, e.g. such that the heat source or portion thereof extending into the containment region remains immersed.

According to a second aspect of the invention, there is provided a steam production system for an oilfield exploration or production facility, e.g. for producing steam in a designated EX Zone or Safe Zone of an oilfield exploration or production facility, the steam production system configured to be connected to facility water and facility electrical power, the steam production system comprising: a steam generator unit in accordance with any preceding claim; and at least one pre-heater to pre-heat water to be supplied to the containment structure of the steam generator unit.

Typically, the pre-heater comprises at least one electrically operable heat source for preheating the water that is configured to be connected to another facility power outlet, e.g. facility three-phase electrical power outlet in examples of the system connecting to facility three-phase electrical power.

The heat source of either or both the steam generator and the pre-heater device may be an electrical heating element. For example, the electrical heating element can be an electrical resistance element.

The steam production system may further comprise a pre-processing system including the at least one pre-heater.

Preferably, the steam production system is operable from facility electrical power. Typically, the oilfield exploration or production facility has multiple electrical power outlets, e.g. threephase electrical power outlets. The steam generator unit may be electrically powered through one or more of the electrical power outlets. The pre-heater may be electrically powered through one or more other ones of the electrical power outlets. The facility may be an offshore or onshore rig or platform.

A given power outlet may preferably be dedicated to only one electrically operable heat source of the system and may not be used for any other electrically operable heat source of the steam production system. Typically, the electrically operable heat source, i.e. that of either or both

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the steam generator unit and the pre-heater, may be power adjustable and controllable to vary the output amount of heat energy. In various examples, the steam generator unit may have a plurality of electrically operable heat sources to heat water and generate steam therein. Each heat source may typically be configured to be connectable to its own electrical power outlet of the facility. Each heat source may be power adjustable and controllable. In the absence of available power outlets, e.g. three-phase electrical power outlets, for all heat sources, one or more of the heat sources may not be connected and used.

The at least one heat source of the steam generator may heat the water and/or steam contents in the containment structure. The or each electrical heat source may be arranged in heat transfer proximity to a water containment region inside the containment structure. The or each heat source may be an electrically powered element that protrudes into the inside of the containment structure. In use, the or each electrical heat source may be immersed in water contained in the containment structure. The containment structure may be a tank for containing steam and water therein.

Preferably, the steam generator has a steam outlet that is openable or closable to output steam from the steam generator for work task use. The steam outlet may be closed to facilitate increasing and obtaining desired pressure and/or temperature conditions of steam in the steam generator unit. When closed, the heat source of the steam generator may be operated to add heat to the steam and/or water contents in the containment structure to generate steam and/or increase temperature and/or pressure therein. In this way, any of wet steam, dry steam, and super-dry steam may be produced. The steam outlet may be opened for supplying the steam to be used in one or more steam work tasks at the facility.

Optionally, the steam generator may have water outlet that is openable and closable. In normal production operations in which steam is generated from supplied water in the steam generator, the water outlet as well as the steam is closed. The water outlet may be opened for returning water to the pre-processing system in a system preparation phase.

Preferably, the pre-processing system is arranged to supply heated water to the steam generator. Further preferably, the pre-processing system may be configured to supply the heated water to the steam generator intermittently from time to time, e.g. when required, such as when water in the steam generator unit drops below a pre-determined water level. The pre-

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processing system may then be operated to supply heated water for a limited time to replenish water that has been converted into steam in the steam generator and/or that has been output from the steam generator unit. The steam production system may have at least one flowline which may couple the pre-processing system to the water inlet of the steam generator unit, and which may include at least one valve that may be operable to open or close the supply of heated water from the pre-processing system to the steam generator unit, when required.

Preferably, the steam production system includes at least one control unit or device for operating and/or controlling the steam production system. More specifically, the control unit or device may controllably operate the or each electrically operable heat source of the steam generator, the or each electrically operable heat source of any pre-heater device or unit.

The pre-heater may be or comprise at least one first type pre-heater device comprising:

a large capacity tank for containing water;

a large containment region within the large capacity tank;

at least one electrically operable heating source in heat transfer proximity to the large containment region for heating the water in the containment region of the tank.

The first type pre-heater device can be considered a large heating tank device. The first type pre-heater device may be configured for long residency storage of water, lower water throughput, large water storage capacity. The large heating tank has a water storage capacity of 100 litres or more. The large heating tank may have a water storage capacity in the range of 100 to 10000 litres.

The pre-heater may be or comprise at least one second type pre-heater device comprising:

a small capacity tank for containing water;

a small containment region within the small capacity tank;

at least one electrically operable heating source in heat transfer proximity to the small containment region for heating the water in the containment region of the tank.

The second type pre-heater device can be considered a small heating tank device. The second type pre-heater device may be configured for short residency storage of water, high water throughput, low water tank capacity. The small heating tank has a water storage capacity of 10 litres or more. The small heating tank may a water storage capacity of 10 to 1000 litres.

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The pre-heater may be or comprise at least one third type pre-heater device comprising: a pipe section for containing a flow of water therethrough;

a heating region within the pipe section;

at least one electrically operable heating source in heat transfer proximity to the heating region for heating the water in the heating region.

The third type pre-heater device can be considered a booster device. The third type pre-heater device may be configured for short residency containment of water, high water throughput, little or no water storage capacity, and/or rapid heat transfer.

The pre-processing system may include:

at least one large capacity tank for containing heated water; and

at least one second or third type pre-heater device to heat water and coupled to the large capacity tank for conveying heated water to the large capacity tank.

The pre-processing system may include two or more pre-heater devices, including at least one device of the first type, and at least one device of the second or third type.

In certain examples, the pre-processing system may include: a first type pre-heater device arranged between a second or third type pre-heater device and the steam generator unit; or a large capacity tank for containing heated water, arranged between a second or third type preheater device and the steam generator unit. Heated water may thus be supplied from the second or third type pre-heater device to the first type pre-heater device or the large capacity tank, and therefrom to the steam generator unit. In such an example, the second or third type pre-heater device may raise the temperature of the water before being supplied to the first type pre-heater device or storage tank for storage in the large tank.

In certain examples, the pre-processing system may include: a second or third type pre-heater device arranged between a first type pre-heater device and the steam generator; or a second or third type pre-heater device arranged between a large capacity tank and the steam generator. Heated water may thus be supplied from the first type pre-heater device or the large capacity tank to the second or third type pre-heater device, and therefrom to the steam generator unit. In such an example, the second or third type pre-heater device may raise and

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boost the temperature of the water from the large tank or the first type pre-heater device before the water enters the tank of the steam generator.

In certain examples, a second or third type pre-heater device may be arranged between a first type pre-heater device and the steam generator.

The heat source or sources of the steam generator and/or the heat source or sources of any pre-heater device may be configured to be connected to a facility electrical power outlet, e.g. a facility three-phase power outlet. Each such heat source may be configured to connect to its own electrical, e.g. three-phase, power outlet of the facility. Typically, the electrically operable heat source may be an electrical heating element. For example, the electrical heating element can be an electrical resistance element. Typically, each such electrically operable heat source may be power adjustable and controllable to vary the output amount of heat energy. In various examples, the steam generator or any one pre-heater device may have a plurality of electrically operable heat sources to add heat energy to water therein.

In the absence of available power outlets for all heat sources, one or more of the heat sources may not be connected and not used. In pre-heater devices of the second or third type that include a tank, the or each heat source may be an electrically powered heating element that protrudes into an inside of the tank, such that the or each electrical heating element may be immersed in water contained in the tank, in use.

Preferably, the pre-processing system may be configured to be supplied with water from a facility water supply. Optionally, the pre-processing system may include a water treatment system arranged upstream of the pre-heater device or devices, e.g. between the facility water supply and the pre-heater device or devices. The water treatment system may comprise one or more water cleaning devices for cleaning or purifying the water. For example, one or more filters for removing particles from the water.

Optionally, the steam production system may include: heat recovery means configured to recover heat from output products of the steam generator, e.g. used steam or water from the steam generator, and which may produce heated heat recovery water from the recovered heat. The steam production system may further include a flowline for directing the heat recovery water into the pre-processing system or a tank of the pre-heater. The heat recovery water may

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be supplied to the at least one pre-heater device of the pre-processing system, e.g. into the large storage tank of a third type pre-heater device.

For instance, steam from the generator after use in one or more steam tasks may transform to water resulting in hot wastewater. The hot wastewater may be fed back into the pre-processing system and supplied to the at least one pre-heater device, e.g. into the large storage tank of a third type pre-heater device. The heat recovery means may include a heat exchanger. Used steam may be recovered through one side of the heat exchanger to heat water on the other side of the heat exchanger, which heated water may be fed back into the pre-processing system and supplied to the at least one pre-heater device of the pre-processing system, e.g. into the large storage tank of a third type pre-heater device. Used hot water from the steam generator tank, e.g. after use, can similarly be recovered and fed back to the pre-processing system optionally through a heat exchanger.

Typically, the control unit or device of the system or the steam generator may be configured to controllably operate: at least one electrically operable heat source, for example control variably or by intermittent switching on or off, e.g. for varying the amount of energy that the electrical heat source outputs; at least one inflow valve for controlling intake of water from the preprocessing system into the steam generator; at least one outflow valve for controlling outflow of steam out of the steam unit.

Typically, the control unit or device may be configured to control the steam production system based on obtained data. The steam generator may include a detector for detecting a water level of water in the containment structure of the steam generator. The control unit or device may be configured to operate steam production system, e.g. including one or more valves, to take in water from the pre-processing system based on the detected water level. The steam generator may include a temperature sensor for detecting a temperature in the containment structure. The steam generator may include a pressure temperature for detecting a pressure in the containment structure. The control unit or device may be configured to operate the steam production system based on the detected temperature and/or pressure conditions. The control device may be configured to operate the steam production system based on detected temperature conditions of heated water in the pre-processing system.

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Typically, any electrically operable heat source of the steam generator or of any pre-heater device may be configured to be connected to power outlets to be supplied with three-phase power at any voltage selected from 400 V, 440 V, 480 V, 660 V, and 690 V and at 50 or 60 Hz. These may be typical three-phase power voltages of oilfield exploration and production facilities. The steam generator or at least one pre-heater device may be configured for multivoltage supplies. Thus, the electrical operable heat source may be operated with electrical power supplied at different voltages, as may be selected or desired depending upon the power supply of the facility and/or available power outlets at the desired use location for the system at the facility. The electrically operable heat source may typically operate with supplied electrical power of at least 50 kW or more. In certain examples, the operating power of each heat source may be in the range of 50 to 200 kW or 50 kW to 500 kW.

Typically, the steam production system is an ATEX zone steam production system, i.e. meets the ATEX zone requirements. Typically, the steam production system may be suitable for being deployed on the offshore facility in hazardous areas and/or in any of Zone 0, Zone 1, Zone 2, or Safe Zone. The system may be configured to be applied in a hazardous area on the oil and gas exploration or production facility.

Typically, the steam production system may be disposed on and within the lateral dimensions of a handling frame. Preferably, the handling frame may be sized to fit within the base area of a standard container. Preferably, the handling frame with the steam production system disposed thereupon may be mobile and configured to be lifted by crane into the desired use location on the offshore facility. For example, the handling frame may be configured with lifting lugs to facilitate lifting.

Typically, the steam production system or any one or all of the electrical heating source(s) of the steam production system may be configured to have multi-voltage capability or capability to be operated by the offshore power supply at voltages of any or all of 400 V, 440 V, 480 V, 660 V, and 690 V, and supplied at 50 or 60 Hz.

Typically, the facility may be an onshore or offshore rig or platform. The rig or platform may be a floating rig or platform or a bottom fixed rig or platform.

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The steam production system may be an electric steam production system. The steam production system may operate using only electrical power.

Optionally, in certain examples, before normal steam production operations commence, the pre-processing system may be prepared. In the preparation of the pre-processing system, the at least one pre-heater device of the pre-processing system may be operated to heat and store heated water. In addition, water to be heated and stored in the pre-processing system may be circulated from the pre-processing system through the steam generator and returned back to the pre-processing system. In the preparation of the processing system, the water outlet of the steam generator is opened. In addition, at least one electrically operable heat source of the steam generator tank is used to heat the water in the steam generator tank, and the water is then returned to the pre-processing system through the opened water outlet. Thus, circulation through the steam generator is provided whereby water enters the steam generator tank from the pre-processing system is heated using the electrical heat source of the steam generator and returned back out of the steam generator tank through the water outlet. Thus, in the preparation of the pre-processing system both the pre-heater device(s) of the preprocessing system and the heat source of the steam generator is used to effect heating of the water to desired heated water temperature. This makes use of the heat sources available in the steam generator allowing for preparing the pre-processing system and brining the steam generation system into readiness for steam generation more quickly.

According to a third aspect of the invention, there is provided apparatus for use in the steam production system of the second aspect of the invention in the form of a unitary structure including the steam generator unit and either or both of at least one pre-heater device and at least one tank for containing heated water. The apparatus may include a supporting frame to which the steam generator unit and the pre-heater and/or tank are mounted. The apparatus may be containerized or may be configured to be containerized within a shipping container approved for lifting on/off any vessel and between a vessel and an offshore rig/platform facility. The shipping container may be a 20 or 40 ft shipping container. The apparatus may be configured to be supported upon a lifting frame approved for lifting on/off any vessel and between a vessel and an offshore rig/platform facility.

According to a fourth aspect of the invention, there is provided a pre-processing system for use in a steam production system in accordance with the second aspect of the invention, the

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pre-processing system including at least one pre-heater to heat water to be supplied to the steam generator. The pre-heater may be a pre-heater device or unit as described in relation to any other aspect and/or wherever described herein.

According to a fifth aspect of the invention, there is provided a method of operating the steam production system in accordance with the second aspect of the invention on an oilfield exploration of production facility, the steam production system arranged to be supplied with facility water and facility electrical power.

According to a sixth aspect of the invention, there is provided a method of producing steam on an oilfield exploration or production facility, the facility to supply facility water and facility electrical power, the method comprising the steps of: providing a steam generator unit in accordance with the first aspect of the invention on the facility; supplying the steam generator unit with water; containing steam and water in the containment structure of the steam generator unit; and using the heat source to emit heat energy, thereby to generate steam from the water within the steam generator containment structure.

Preferably, the method may further comprise pre-heating water and supplying the containment structure with pre-heated water. The method may include first stage pre-heating of water and second stage pre-heating of water. The first stage pre-heating may be performed using at least one pre-heater device or unit and second stage pre-heating may be performed using at least one further pre-heater device or unit. The method may further comprise supplying heated water from the one pre-heater device to the further pre-heater device and supplying heated water from the further pre-heater device to the steam generator unit. The method may include outputting steam from the tank of the steam generator unit to perform a steam task.

In certain examples, heated water provided by the at least one pre-heater device or unit by the first stage pre-heating may have a temperature in the range of 40 to 60 degrees Celsius. Further heated water provided by the at least one further pre-heater device or unit by the second stage pre-heating may have a temperature of around 98 degrees Celsius.

In advantageous examples, the method may further comprise any of: providing a first preheater device or unit, containing water within a tank of the first pre-heater device or unit,

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supplying the tank of the first pre-heater device or unit with water, using an electrically operable heat source, adding heat energy to the water within the tank, thereby obtaining first heated water; providing a second pre-heater device or unit, supplying a tank of the second pre-heater device or unit with water from the first pre-heater device or unit; supplying the steam generator unit with pre-heated water from the second pre-heater device or unit; controlling the electrically operable heat source of the first pre-heater device or unit such that the first heated water has a first temperature; controlling the electrically operable heat source of the second pre-heater device or unit such that the second heated water has a second temperature which is higher than the first heated water. The first temperature may be in the range of 40 to 60 degrees Celsius. The second temperature may be in the range of 90 to 99 degrees Celsius.

The water capacity of the first pre-heater device or unit may be larger or smaller than the capacity of the second pre-heater device or unit. Any pre-heater device or unit herein may be, or may comprise any one or more of: a first-type, second-type, or third-type pre-heater device.

The oilfield exploration or production facility may be an offshore facility or an onshore facility such as be a rig or platform, floating or bottom fixed.

Embodiments of the invention may be advantageous in various ways as will be apparent from throughout. For example, an electrical steam generator unit for producing steam from supplied water by electrically operable heat source can be controllable to provide the desired heating. The electrical power may be drawn from the local electrical circuit of the offshore oil and gas facility. The steam generator unit may typically have a control device with CPU control for controlling the electrically operable heat source for controlling the supply of energy to the water and/or the amount of steam produced. Thus, the steam may advantageously produce and deliver the specific required amount of steam required for a particular application, i.e. without significant excess / waste. The system and/or units thereof may be to the rig/platform as a temporarily installed mobile unit.

By means of the multiple units or devices with water heating capabilities, multistage heating of the water and production of steam may be provided where each unit individually may have relative low power draw requirements, making the steam production system particularly suited for use offshore. Multi-stage heating (pre-heating tanks / booster units) may increase the amount of steam produced per installed KW. A prior art diesel unit would typically produce 1.5

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kg of steam per hour and installed KW. In contrast, examples of the electric steam generator unit and steam production systems herein may produce 2-6 kg of steam per hour and installed KW. This may be facilitated through pre-heating of water in the pre-preheater devices or unit(s) e.g. one unit comprising heating tanks and the other unit comprising smaller booster units to increase capacity of the steam generator unit.

The steam production system can in various examples be regarded a multi-stage electrical steam production system, and since through only providing electrical heating to operate the system may achieve zero CO2 emissions during operation. It can also be run remotely controlled to control the heating and steam generation, which can reduce need for people in the red zone.

Preferably, the steam capacity is in the range of 300 to 15000 kg/hr. Preferably, the steam generator can run off power 250kW available rig/platform power. Preferably, the steam generator is ATEX certified (explosion proof). Preferably, the steam generator is mobile and temporarily installed. Preferably, the steam generator has smart and remote operation capability (control unit, sensor package, and remote control). Preferably, the steam generator has power inputs of 400/440 V and 660/690 V.

Preferably, the steam generator is applied for tasks such as: steam generation (surface cleaning, tank cleaning); heating chemicals; hydrogen removal (welding); heating/radiators; de-icing/heating of larger surfaces.

Any of the various aspects or features thereof may include one or more further features as described in relation to any other aspect wherever described herein.

Specific description and drawings

There will now be described, by way of example only, embodiments of the invention, with reference to the accompanying drawings, in which:

Figure 1A is a schematic side representation of an offshore oil and gas exploration or production facility comprising a marine platform including a steam production system according to an example;

Figure 1B is a schematic overhead view of the facility of Figure 1A;

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Figure 2 is a further schematic representation of the steam production system of Figures 1A and 1B;

Figure 3 is an example representation of a steam generator unit for producing steam from supplied water according to an example;

Figure 4 is an example representation of a first pre-heater unit for heating water;

Figure 5 is an example representation of a second pre-heater unit for heating water; Figure 6 is a schematic representation of a control device;

Figure 7 is a flow diagram showing different example for the supply of water to the steam generator unit;

Figure 8 is a schematic representation of steam production system according to another example;

Figure 9A is a schematic side representation of an offshore oil and gas exploration or production facility comprising a marine platform including a steam production system according to another example;

Figure 9B is a schematic overhead view of the facility of Figure 9A; and

Figure 10 is a further schematic representation of the steam production system of Figures 1A and 1B.

Turning firstly to Figures 1A and 1B, the oil and gas exploration or production facility 10 has a steam production system 50 onboard. The facility 10 in this example is an offshore oil and gas production or exploration platform at a well site 2. Wellbore tubing 3 extends from the platform and into the wellbore 4 in the rock layers 5 below the seabed 6. The steam production system 50 is arranged on a deck structure 12 above the sea surface 7.

The steam production system 50 has a first pre-heater unit 100, a second pre-heater unit 200, and a steam generator unit 300. A facility water supply 8 on the offshore facility supplies water to the steam production system, for example in the form of cold fresh water. The water is heated first by the first pre-heater unit 100 (first heating stage) and then further heated by the second pre-heater unit 200 (second heating stage) and then is supplied as required and turned into steam by the steam generator unit 300. Steam from the steam generator unit 300 is then used for performing an industrial task on the platform such as for cleaning equipment used in the oil and gas exploration or production process.

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Each of the first pre-heater unit 100, the second pre-heater unit 200, and the steam generator unit 300 operates using an electrically operated heat source which supplies heat to the water in the respective unit. The electrically operable heat sources are connected to a three-phase electrical supply 30 of the offshore facility. The facility has multiple three-phase power outlets 31, 32, 33 for obtaining connections to the three-phase power supply. Each of the units 100, 200, 300 is connected to one of the three-phase power outlets, allowing them to be operated electrically independently of each other. In various examples, each heat source is connected to a separate three-phase electrical power outlet 31, 32, 33.

As seen now with reference additionally to Figure 2, the first pre-heater unit 100 comprises one or more large-capacity tanks 110 for storing water. The tank 110 of the first pre-heater unit is a large capacity tank. Cold water from the supply 8 on the offshore facility 1 is supplied to the one or more tanks 110 of the pre-heater unit 100. Typically, the cold water has a temperature in the region of 5 to 30 degrees Celsius. The electrically operable heat source 102 is arranged in heat transfer proximity to the tank interior to heat the water in the tank 110. The water in the tank 110 is heated to around 50 degrees Celsius. The pre-heater unit 100 includes a control device 140 for controlling the operation of the pre-heater unit 100. The control device 140 is configured to control the operation of the electrically operable heat source 102 to add heat energy to the water to heat the water and/or to maintain the temperature of the water as required. The control device 140 is for example operated to switch on or off or adjust the electrical power to the heat source 102. For example, a desired temperature of around 50 degrees Celsius may be pre-defined for water in the tank, and a temperature sensor is provided to detect the temperature in the water in the tank, and the control device 140 operates the heat source to add heat energy for heating the water in the tank 110 in dependence upon the detected temperature, e.g. if determined not to have reached the pre-defined desired temperature. In order to reduce heat losses to surroundings, the one or more tanks 110 are insulated. Water is supplied to the tank(s) of the pre-heater unit 100 to replenish the water exiting the tanks to produce steam. Thus, whilst steam is being produced, water from the source 8 enters the tank and is heated in the tank. Being a large tank of water that is already heated, as new water enters from the source, the new water can be efficiently heated and the water temperature overall maintained readily and accurately by operating the electric heating element 102.

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The second pre-heater unit 200 comprises one or more small-capacity tanks for storing water. The tanks are insulated. In this example, four tanks 210 are shown. The tanks 210 of the second pre-heater unit 200 are of smaller capacity, far smaller than the tank(s) 110 of the first pre-heater unit 100. Heated water from the first pre-heater unit 100 and having a temperature of around 50 degrees Celsius is supplied to the four tanks 210 of the pre-heater unit 200. Each tank 210 has an electrically operable heat source 202 is arranged in heat transfer proximity to the tank interior to further heat the water in the tank 210. The water in each tank 210 is heated to around 98 degrees Celsius.

The second pre-heater unit 200 includes a control device 240 for controlling the operation of the pre-heater unit 200. The control device 240 is configured to control the operation of the electrically operable heat sources 202 to add heat energy to the water in each tank in order to heat the water and/or to maintain the temperature of the water as required. Thus, the second pre-heater unit 200 is controllable using the control device 240 separately from the first preheater unit 100. The control device 240 is for example operated to switch on or off or adjust the electrical power to the electrically operable heat sources 202. For example, a desired temperature of around 98 degrees Celsius may be pre-defined for water in the tank 210, and a temperature sensor is provided to detect the temperature in the water in the tank, and the control device 240 operates the heat source 202 to add heat energy for heating the water in the tank 210 in dependence upon the detected temperature, e.g. if determined not to have reached the pre-defined desired temperature. Being thermally insulated the tanks 210 resist heat loss to surroundings, helping to keep temperature under control of the heating element 202 and controller 240. Water is supplied to the tank(s) of the second pre-heater unit 200 to replenish the water exiting the tanks 210 to be used to produce steam. Thus, whilst steam is being produced in the steam generator unit 300, water from the first pre-heater unit 100 enters the tanks 210 and is heated in each tank 210. Being small tanks of water, as new water enters the tanks 210 from the first pre-heater unit 100, the new water can be efficiently heated, and the water temperature relatively rapidly raised by operating the electrically powered heat sources 202. Depending on the required amount of steam, in other examples only one or some of the tanks of the second pre-heater unit 200 are used. In other examples still, the preheater unit has a different number of tanks 210, or for example only one tank.

The steam generator unit 300 has a steam generator tank 310 for containing water and steam. Steam is generated from supplied water in the tank 310 such that a reservoir of steam is

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established in the tank 310. Heated water from the second pre-heater unit 200 and having a temperature of around 98 degrees Celsius is supplied to the tank 310 of the steam generator unit 300. The tank 310 has an electrically operable heat source 302 is arranged in heat transfer proximity to the tank interior to further heat the water in the tank 310. The heat source 302 is immersed in water within the tank 310. The water in each tank 310 is heated and/or maintained to above the boiling point of the water. Thus, the water in the steam generator tank 310 is heated to above 100 degrees Celsius, steam thus being produced from the boiling water in the tank. When required, further heated water from the pre-heater units 100, 200 is supplied to the tank 310, e.g. when the water level falls below a certain level upon the consumption or generation of steam in due course. Generated steam can then be output from the tank of the steam generator unit 300 for use in a downstream work task such as cleaning of equipment or workspaces or the like.

The steam generator tank 310 of the steam unit 300 has greater capacity than the total or individual capacities of tanks of the second pre-heater unit 200. The steam generator tank 310 of the steam unit 300 has lesser water capacity than the total or individual tanks of the tank(s) 110 of the first pre-heater unit 100.

The steam generator unit 300 includes a control device 340 for controlling the operation of the steam generator unit 300. The control device 340 is configured to control the operation of the electrically operable heat source 302 to add heat energy to the water in the tank 310 in order to heat the water and/or to maintain the temperature of the water at or above boiling point. Thus, the steam generator unit 300 is controllable using the control device 340 separately from the first pre-heater unit 100 and the second pre-heater unit 200. The control device 340 is for example operated to switch on or off or adjust the electrical power to the electrically operable heat source 302. For example, a desired temperature of above 100 degrees Celsius may be pre-defined for water in the boiler tank 310, and a temperature sensor is provided to detect the temperature of contents in the tank 310, and the control device 340 is operated to supply electrical three-phase power to the electrically operated heat source 302 to add heat energy for heating the water in the tank 310 in dependence upon the detected temperature if determined not to have reached the pre-defined desired temperature. Water is supplied to the steam generator tank 310 to replenish the water which is converted to steam and outputted from the tank 310. Thus, whilst steam is being produced in the steam generator unit 300, water from the second pre-heater unit 200 can enter the tank 310, when required for

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replenishment and/or steam generating performance, and be supplied with heat energy. In certain examples, the boiler tank 310 is insulated to avoid undesired heat loss to surroundings.

Certain examples of the first pre-heater unit 100, second pre-heater unit 200, and steam generator unit 300 will now be described with reference additionally to Figure 3. In Figure 3, the steam generator unit 300 has a steam generator tank 310, an electrically operable heat source 302, and controller 340. Further, the tank 310 comprises a chamber 311, a water supply inlet 312, and a steam outlet 313 from the chamber. Water is received in the chamber 311 through the inlet 312. The electrical heat source 302 is arranged in heat transfer proximity to the chamber interior to supply heat energy to the water in the chamber 311 for obtaining and/or maintaining generation of steam from water. Steam is produced in the chamber 311 and leaves the chamber 311 through the outlet 313. A pipe 314 is connected to the inlet 312 providing fluid communication through the pipe 314 and the inlet 312 into the chamber 311. A controllable valve 316 is provided in the pipe 314. A further pipe 315 is connected to the outlet providing fluid communication for steam out of the chamber and the outlet 313 and onward through the pipe 315. A controllable valve 317 is provided in the pipe 315. A temperature sensor 318 is provided for detecting the temperature of contents in the boiler tank 310.

The valves 316, 317, and the heat source 302 are arranged to be controlled by the control device 340. In the example, control lines connect from the control device to each of the valve 316, the valve 317, and the electrically operable heat source 302. Also, the control device 340 is connected to the temperature sensor 318. In the example, a control line connects the control device 340 to the temperature sensor 318. The control device 340 is arranged to receive temperature data from the temperature sensor 318. The control device 340 is arranged to pass instructions to the valves 316, 317 for operating the valves 316, 317. The valves 316, 317 may be operated to open, close, and/or control the amount of flow through the valve. Valve 316, 317 may control the inflow of water into the tank 310. The valve 317 may control the outflow of steam from the tank 310. The control device 340 is arranged to pass instructions to the electrically operable heat source 302 for operating the electrically operable heat source 302. The electrically operable heat source 302 may be operated to switch on, switch off, and/or adjust the amount of heat energy delivered from the heating element 302 to the water in the tank 302. The electrically operable heat source 302 is operated to maintain the water above boiling point. The valves 316, 317 are operated to control the amount of water entering and steam leaving the tank, in appropriate amounts to allow operation of the electrically operable

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heat source 302 to maintain and/or heat the temperature effectively above the boiling point in the tank 310. The control device 340 is configured to control the electrically operable heat source 302 dependent or based upon the temperature data from the sensor 318. The electrically operable heat source 302 is connected to a three-phase power outlet 33 on the offshore facility.

In Figure 6, the control device 340 has a microprocessor 341, memory 342, and an In/Out unit 343. The memory 342 is used for storing data such as one or more computer programs and data. The computer program comprises machine readable instructions which when executed by the microprocessor can cause the control device to issue instructions foe operating one or more components of the steam unit, e.g. the valves 316, 317, sensor 318, electrically operable heat source 302, etc. The In/Out unit 343 is used for the input or output of data or instructions for example to or from the temperature sensor 318, the electrically operable heat source, the valve 316, 317, etc. The In/Out unit 343 in the example includes a wireless communication transponder 345 for allowing remote communication with the control device 340. The control device 340 can be remote controlled or reprogrammed over a wireless network link to the transponder 345. The control device 340 also has a display 344 for displaying data associated with the status of the steam unit 300 or other information. The microprocessor 341 is used for processing data and executing one or more computer programs for issuing instructions for controlling the steam unit 300 and components thereof such as the valves 316, 317, sensor 318, and electrically operable heat source 302.

In Figure 4, the first pre-heater unit 100 has two large storage tanks 110 each having an electrically operable heat source 102, and controller 140. The unit 100 can in this respect be regarded as including two pre-heater devices generally of the first type, arranged in parallel. Each tank has large water storage capacity and the water storage capacity is greater than that of the boiler tank of the steam unit. Further, the storage tank 110 comprises a chamber 111, an inlet 112, and an outlet 113 from the chamber 111. Water is received in the chamber 111 through the inlet 112. The electrically operable heat source 102 is arranged in heat transfer proximity to the chamber interior to supply heat energy to the water in the chamber 111 thereby heating and raising the temperature of the water in the chamber and/or controlling or maintaining the temperature of the water in the chamber to keep within certain limits. Typically, the temperature of the water in the chamber is around 50 degrees Celsius. The water which is heated or maintained at the defined temperature in the chamber 111, within certain limits,

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e.g. the water of around 50 degrees Celsius, is extracted from the chamber 111 through the outlet 113. First pipes 114 are connected to the inlets 112 providing fluid communication through the pipes 114 and the inlets 112 into the chambers 111. Controllable valves 116 are provided on the first pipes 114. Further pipes 115 are connected to the outlets 113 providing fluid communication for water out of the chambers 111 and the outlets 113 and onward through the pipe 115. Controllable valves 117 are provided in the pipes 115. Temperature sensors 118 are provided for detecting the temperature in the water in the storage tanks 110.

The valves 116, 117, and the heat source 102 are arranged to be controlled by the control device 140. In the example, control lines connect from the control device to each of the valves 116, the valves 117, and the electrically operable heat sources 102. Also, the control device 140 is connected to the temperature sensors 118. In the example, a control line connects the control device 140 to the temperature sensor 118. The control device 140 is arranged to receive temperature data from the temperature sensor 118. The control device 140 is arranged to pass instructions to the valves 116, 117 for operating the valves 116, 117. The valves 116, 117 may be operated to open, close, and/or control the amount of flow through the valve. Valve 116, 117 may control the inflow of water into the tank 110. The valve 117 may control the outflow of heated water from the tank 110. The control device 140 is arranged to pass instructions to the electrically operable heat source 102 for operating the electrically operable heat source 102. The electrically operable heat source 102 may be operated to switch on, switch off, and/or adjust the amount of heat energy delivered from the heating element 102 to the water in the storage tank 110. The electrically operable heat source 102 is operated to maintain the water at a certain temperature or within certain temperature limits. The valves 116, 117 are operated to control the amount of water entering and steam leaving the tank, in appropriate amounts to allow operation of the electrically operable heat source 102 to maintain and/or heat the temperature to the desired temperature, e.g. 50 degrees Celsius, or within certain desired temperature limits. The control device 140 is configured to control the electrically operable heat source 102 dependent or based upon the temperature data from the sensor 118.

The electrically operable heat sources 102 are each connected to a three-phase power outlet 31 on the offshore facility.

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The control device 140 is as described above in relation to the control device 340 except operable to control the temperature and heating of the water in the storage tanks as appropriate for the pre-heater unit 100. Features of the pre-heater unit 100 and the steam unit 300 to be considered to correspond or are similar in this respect are referenced in the drawings using the same reference numerals incremented by two hundred.

In Figure 5, the second pre-heater unit 200 has four storage tanks 210 each having an electrically operable heat source 202, and controller 240. Each tank 210 has small water storage capacity. The water storage capacities of the tanks 210 both individually and collectively is smaller than that of the boiler tank 310 of the steam unit 300 and smaller than that of the storage tanks 110 of the first pre-heater unit 100. The unit 200 can in this respect be regarded as including four pre-heater devices generally of the second type, arranged in parallel.

Each storage tank 210 comprises a chamber 211, an inlet 212, and an outlet 213 from the chamber 211. Water is received in the chamber 211 through the inlet 212. The electrically operable heat source 202 is arranged in heat transfer proximity to the chamber interior to supply heat energy to the water in the chamber 211 thereby heating and raising the temperature of the water in the chamber 211 and/or controlling or maintaining the temperature of the water in the chamber to keep within certain limits. Typically, the temperature of the water in the chamber is around 98 degrees Celsius. The water which is heated or maintained at the defined temperature in each chamber 211, within certain limits, e.g. the water of around 98 degrees Celsius, is extracted from the chambers 211 through the outlets 213. Common pipe 222 is connected to first pipes 214 which in turn are connected to the inlets 212. Water is fluidly communicable through the common pipe 222, first pipes 214 and the inlets 212 into the chambers 211. A controllable valve 216 is provided on the common pipe 222. Second pipes 215 are connected to the outlets 213 and the second pipes 215 are in turn connected to common pipe 223. Water is fluidly communicable out of the chambers 211, through the outlets 213 and the second pipes 215 and through the common pipe 223 for onward conveyance. A controllable valve 217 is provided in the pipes 215. Temperature sensors 218 are provided for detecting the temperature in the water in the storage tanks 210.

The valves 216, 217, and electrically operable heat sources 202 are arranged to be controlled by the control device 240. In the example, control lines connect from the control device 240

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to each of the valves 216, 217, and the electrically operable heat sources 202. Also, the control device 240 is connected to the temperature sensors 218. In the example, a control line connects the control device 240 to the temperature sensors 218. The control device 240 is arranged to receive temperature data from the temperature sensors 218. The control device 240 is arranged to pass instructions to the valves 216, 217 for operating the valves 216, 217. The valves 216, 217 may be operated to open, close, and/or control the amount of flow through the valve. Valve 216 may control the inflow of water into the tanks 210. The valve 217 may control the outflow of steam from the tanks 210. The control device 240 is arranged to pass instructions to the electrically operable heat sources 202 for operating the electrically operable heat sources 202. The electrically operable heat sources 202 may be operated to switch on, switch off, and/or adjust the amount of heat energy delivered from the heating element 202 to the water in the tank 210. The electrically operable heat source 202 is operated to maintain the water at a certain temperature or within certain temperature limits. The valves 216, 217 are operated to control the amount of water entering and steam leaving the tanks 210, in appropriate amounts to allow operation of the electrically operable heat sources 202 to maintain and/or heat the water to the desired temperature, e.g. approximately 98 degrees Celsius, or to within specified temperature limits. The control device 240 is configured to control the electrically operable heat sources 202 dependent or based upon the temperature data from the sensors 218.

The electrically operable heat sources 202 are each connected to an electrical three-phase power outlet 32 of the facility.

The control device 240 is as described above in relation to the control device 340 except operable to control the temperature and heating of the water in the storage tanks as appropriate for the pre-heater unit 200. Features of the pre-heater unit 200 and the steam unit 300 to be considered to correspond or are similar in this respect are referenced in the drawings using the same reference numerals incremented by one hundred.

As can be appreciated from Figure 7, in some examples, the steam unit 300 is supplied directly with cold water from the platform water supply 8. The steam unit can be supplied with cold water without any pre-heater devices being used or supplied with heated water via one or more pre-heater devices. Various permutations of pre-heating are possible, as indicated in Figure 7.

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Figure 8 depicts generally a steam production system 1050 in a restricted zone, typically designated EX Zone or Safe Zone, of an oil and gas exploration or production facility. Features of the steam production system 1050 corresponding to those described above in relation to the steam production system 50 are denoted by the same reference numerals incremented by one thousand.

The steam production system 1050 has a steam generator unit 1300 with a tank 1310 containing supplied water and steam therein. The steam generator unit 130 has electrically powered heat sources 1302 which transfer heat energy to the contents of the tank 1310. Each heat source 1302 is connected to a three-phase power outlet 33 of the rig 10.

The steam generator unit 1300 is supplied with water from a pre-processing system 1060 including in this example two pre-heater devices 1100, 1200. The pre-heater devices 1200 is a second type pre-heater devices in the form of a small capacity tank 1210 for containing water within a containment region thereof and an electrically powered heat source 1202 in heat transfer proximity to the containment region for heating the water in the tank 1210. The preheater devices 1200 has an inlet 1212 for conveying water into the tank and outlet 1313 for conveying water out of the tank. The pre-heater devices 1100 is a first type pre-heater devices in the form of a large capacity tank 1110 for containing water within a containment region thereof and electrically powered heat sources 1102 in heat transfer proximity to the containment region for heating the water in the tank 1110. The pre-heater device 1100 has an inlet 1112 for conveying water into the tank and outlet 1113 for conveying water out of the tank. The pre-heater device 1100 is arranged between the pre-heater device 1200 and the steam generator unit 1300, upstream of the steam generator unit 1300. Each heat source 1102 is connected to a respective three-phase power outlet 31 of the rig 10. The heat source 1202 is connected to a three-phase power outlet 32 of the rig 10.

In certain variants, the pre-processing system 1060 includes another second type pre-heater device arranged between the first type pre-heater device 1100 and the steam generator unit 1300, upstream of the steam generator unit 1300.

The pre-processing system 1060 is connected to a rig water supply 8 which supplies water to the pre-processing system 1060. The pre-processing system processes and heats the water.

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The water processed and heated by the pre-processing system 1060 is supplied to the steam generator 1300 to generate the steam.

The steam production system 1050 includes a control device 1340 for controlling the operation of the system and/or steam generator unit 1300, including operational steps such as described elsewhere herein. In Figure 8, the control device 1340 is connected to the electric heat sources 1102, 1202, 1302 for controlling the operation of the electrical heat sources. For example, the heat energy output of any of the heat sources 1102, 1202, 1302 individually or collectively may be controllably adjusted by instructions from the control device 1340. The heat sources may be controlled in response to temperature or pressure data to achieve desired temperature or pressure conditions of water in or from any of the pre-heater devices and the steam generator tank 1310. The intake of water into the steam generator tank 1310 through the steam generator inlet 1312 may be controlled in response to a pre-determined requirement of the steam generator unit 1300. For example, the intake of water may be controlled to supply and replenish water in the tank 1310 when the water level WL of the tank has dropped to a certain level following generation of steam in the steam unit and/or the outputting of steam from the unit during a steam task. The system may also be controlled as to the timing, rate and duration of supply, required amount, and temperature of the heated water coming from the preprocessing system 1060. The water supply and related conditions may also be controlled according to the requirements and conditions of the steam generator.

In this example, the pre-processing system 1060 includes water treatment means 1370 upstream of the pre-heater devices 1100, 1200. The water treatment means 1370 is arranged between the water supply and the pre-heater device 1100 and includes one or more devices through which water is passed for example to remove particles from the water to be supplied to the pre-heater 1200.

In this example, the steam production system 1050 also includes heat recovery means 1400. Heat recovery water from the heat recovery means 1400 is conveyed through recovery line 1415 to the pre-processing system 1060. More specifically, in this example, the recovery line 1415 connects to a flowline between the pre-heater device 1200 and the pre-heater device 1100. Heated recovery water from the heat recovery means 1400 can thus be conveyed to the tank 1110 of the pre-heater 1100 for re-use in the production of steam from the system. The heat recovery means 1400 includes for example heat exchange apparatus that can

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recovery heat for example from steam that is output from the steam generator through steam outlet 1313 or from hot water that has transformed from steam upon use of the output steam from the outlet 1313 or from hot water that is output from the steam generator unit through water outlet 1323, for example when draining the steam generator tank of water after use.

In operation, cold water is supplied from the rig supply 8 through water treatment means 1370 to the pre-heater device 1200. The cold water has a temperature of 1 degree Celsius or more. The pre-heater device 1200 performs first stage heating of the water in the tank 1210 to produce heated water in the range of 10 to 98 degrees Celsius. The tank 1210 contains 10 litres of water or more. The heated water from the pre-heater 1200 is supplied onward to the pre-heater device 1100. The pre-heater device 1100 performs second stage heating of the water raising or maintaining the water contained in the tank 1110 to a temperature in the range of 10 to 180 degrees Celsius. The tank 1110 contains 100 litres of water or more. The heated water from the pre-heater device 1100 is supplied to the steam generator unit when required, e.g. to replenish the water level in the steam generator tank 1310. The temperature and pressure of steam and/or water contents within the tank 1310 is for example controlled to be in the temperature range of 165 to 170 degrees Celsius and pressure range 1 to 25 bar. In various examples, the steam generator operates with the pressure within a lower region of the range to produce wet steam, or an intermediate region of the range to produce dry stem, or an upper region of the range to produce super-dry steam.

Through supplying the steam generator unit 1300 with heated water from the pre-processing system 1060 greater amounts of steam are producible in the steam generator. The amount of water stored in the tank 1110 of pre-heater device 1100 is conveniently sufficiently large to cover the expected or predetermined requirements of the steam generator unit 1300 in terms of replenishment quantities to maintain the water level WL well above any heat source elements immersed in the water in the tank 1302 or other predetermined desired water level WL.

The steam generation system 1050 can be operated in an operational phase for steam production and establishing a steam reservoir in the steam generator tank 1310, and also in a preparation phase. In the preparation phase, the pre-processing system 1060 is prepared to store heated water of the desired specification in at least the pre-heater device 1100, such that fully heated water from the preheater unit 1100 is available to be supplied to the steam

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generator when desired before moving to the steam generation phase. In the preparation phase, water to be heated and stored in the pre-processing system 1060 is circulated from the pre-processing system through the steam generator tank 1310 and returned back to the preprocessing system. To this end, an outlet, e.g. outlet 1323, in the steam generator is opened, then water from the pre-processing system is supplied into the steam generator tank 1310 through inlet 1312, heated by one or more of the heat sources 1302, then conveyed out of the steam generator tank 1310 through outlet, e.g. 1323, and returned to the pre-heater device 1100. Thus, the heat sources of the steam generator can conveniently assist with heating water for the pre-processing system, in this preparation phase. This may help bringing the steam generation system online and into readiness for the desired steam generation more quickly. The system is switched from the preparation phase to the operational phase and configuration of the steam generator. To do so, the outlet 1323 is closed and steam generation can then commence in the steam generator in the normal way. Indeed, during the generation of steam particularly in order to establish the steam generation and a reservoir of steam of required specification in the steam tank 1310, also the steam outlet 1313 is closed in order to allow the temperature and pressure to be raised as required. Once the steam is generated and a reservoir of steam is established in the tank 1310, the steam outlet 1313 can be opened for required periods to let out steam for performing steam tasks on the facility.

Figures 9A and 9B depicts generally a steam production system 2050 in a restricted zone of an oil and gas exploration or production rig and Figure 10 illustrates further details of the steam production system. Features of the steam production system 2050 corresponding to those described above in relation to the steam production system 1050 are denoted by the same reference numerals incremented by one thousand.

The steam production system 2050 has a steam generator unit 2300 with a tank 2310 containing supplied water and steam therein. The steam generator unit 2300 has electrically powered heat sources 2302 which transfer heat energy to the contents of the tank 2310. Each heat source 2302 is configured to be connected to a three-phase power outlet 33. The steam production system 2050 has a pre-heater device 2100 which is a first type preheater unit including heated water tank 2110 and at least one heat source 2102 immersed in the water containment region of the tank 2110.

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A transportable combined unit 900 is provided in this example comprising various components which together are arranged to be containerized. More specifically, the transportable combined unit 900 to be containerized includes the steam generator 1300, the pre-heater device 2100, and the control device 1540. This combined unit 900 is arranged as a single liftable entity, e.g. mounted on a frame 962, and sized to fit within the dimensions of a standard industrial shipping container, e.g.20 or 40 ft shipping container. This can allow the unit 900 to be pre-configured and conveniently shipped and mobilised as part of routine cargo handling operations to and from the offshore facility. On the facility, the combined unit 900 can be readily moved as one out of the container.

In use, water is supplied to the heated water tank 2110. The water supplied to the heated water tank 2110 can be supplied form rig water supply 8, optionally via another pre-heater device. Water in the heated water tank 2110 is heated by the heat source 2102. Heated water is stored in the tank 2110. Heated water from the tank 2110 is supplied to the steam generator tank 2310 when required, e.g. when water level WL drops by a certain amount. Steam is generated from water in the steam generator tank 2310. A reservoir of generated steam is obtained in the tank 2310. Steam is output through steam outlet 2313 for performing steam tasks when required.

For example, the heated water tank 2110 has a water storage capacity of 1000 to 4000 litres, low pressure (near ambient), and applies heat to the water in the tank to obtain heated water stored in the tank of 100 degrees Celsius or lower. The heated water of tank 2110 may be maintained to have a temperature in the range of 60 to 100 degrees Celsius, for example 90 to 100 degrees Celsius or just below 100 degrees Celsius, for example about 97 to 99 degrees Celsius, such as about 98 degrees Celsius.

For example, the steam generator 2300 is operable to obtains and/or maintains temperature(s) in the contents of the tank 2310 above 100 degrees Celsius, typically in the range of 100 to 180 degrees Celsius, and more typically in the range of 165 to 170 degrees Celsius.

The steam production system 2050 includes a control device for operating the various parts of the system, in particular to control operation of the heat sources 2302, 2102 individually or collectively to produce the necessary heating, wherein any of the heat sources can be switched

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on or off and in some instances if adjustable heat sources are used can be adjusted as to their heat energy output.

Each of the heat sources 2302, 2102 is an electrical heating element supplied individually by a three-phase power outlet on the rig with electric power in the range of around 50 to 500 kW, typically for example 100 to 200 kW at voltages mentioned above at 50 or 60 Hz. In examples, the heating elements are adjustable in power within any of these ranges. The heating elements may then be adjustably controlled through the control device 1540.

The system 2050 in this example has an add-on unit 2800 comprising heated water tank unit 2811 for increasing heated water storage capacity in the system e.g. if the storage capacity of the heated water tank 2110 is not sufficient for the circumstances. This could be useful when there are size and weight limitations to providing further or larger capacity pre-heater devices within the footprint of the combined unit 900. The add-on water tank 2811 is in water exchange communication with the heated water tank 2110 providing a combined interconnected heated water storage reservoir.

In particular, the steam generator 2300 is operable in various production modes including a first, wet steam mode, a second, dry steam mode, and a third, super-dry steam mode. Thus, depending upon user requirements, the system 2050 can produce any of wet steam, dry steam, and super-dry steam from the steam tank 2300.

In the first mode, the system 2050 is operated is controlled so that the steam and/or water in the steam generator tank 2310 has a temperature in the range of 165-170 degrees Celsius and a pressure in the range of 2 to 4 bar (wet steam).

In the second mode, the system 2050 is controlled so that the steam and/or water in the steam generator tank has a temperature in the range of 165-170 degrees Celsius and a pressure in the range of 5 to 8 bar (dry steam).

In the third mode, the system 2050 is controlled so that the steam and/or water in the steam generator tank 2310 has a temperature in the range of 165-170 degrees Celsius and a pressure in the range of 9 to 25 bar (super-dry steam).

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Various modifications and improvements may be made without departing from the scope of the invention herein described. Although each unit 100, 200, 300 in the description above has respective control units 140, 240, 340, in other examples the system instead or in addition has a control unit for controlling the units and the operation of the heating elements. Each of the units 100, 200, 300 can be configured as its own module each on a separate mounting and handling frame so that each can be handled, lifted and/or containerised separately when moving and positioning onto the facility or removing them therefrom. The electrically operable heat source in any example is an electrical heating element which in any example above may be an electrical resistance heating element. Although three-phase power is described in various examples, this is replaced with power that is not three-phase in other variants. The term “pre-heater unit” in any example can be replaced with the term “pre-heater device” or vice versa in any example described above. In any example above, specific numerical values or ranges for pressure, temperature, storage capacities / volume are mere examples and are not limiting upon the example in any other respect except as the context requires. Moreover, any range or value specified for one of any pre-heater device may be applied to any pre-heater device in any other example, and any range or value specified for any the steam generator unit in one example may be applied to any steam generator unit in any other example. Furthermore, any range specified herein is to be regarded a specific disclosure of each and every discrete value within the range. Any range specified herein is also a specific disclosure of all and any sub-range within the specified range, the sub-range having end points of any selected value within the specified range.

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Claims

CLAIMS:

1. A steam generator unit for a designated EX Zone or Safe Zone of an oilfield exploration or production facility, the steam generator unit configured to be connected to facility water and facility electrical power, the steam generator unit comprising:

a containment structure to contain water and steam;

at least one electrically operable heat source configured to be connected to a facility electrical power outlet, the heat source arranged to generate steam from contained water within the containment structure.

2. A steam generator unit as claimed in claim 1, wherein the containment structure has:

a water supply inlet which is openable/closable; and

a steam outlet which is openable/closable.

3. A steam generator unit as claimed in claim 2, wherein the containment structure further has a water outlet which is openable/closable.

4. A steam generator unit as claimed in any preceding claim, wherein the containment structure is a tank to contain water and steam therewithin.

5. A steam generator unit as claimed in any preceding claim, wherein the heat source is provided with an electrical connector for mating with a complementary facility power outlet electrical connector.

6. A steam generator unit as claimed in any preceding claim, having multi-voltage capability for allowing connection to facility power at different voltages and electrically operating the heat source with electrical power from an input supply at one voltage or another voltage.

7. A steam generator unit as claimed in any preceding claim, wherein the heat source has an operating power in the range of greater than 50kW.

8. A steam generator unit as claimed in any preceding claim, further comprising a control unit to control operation of the steam generator unit.

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9. A steam generator unit as claimed in claim 8, wherein the control unit is arranged to control the heat source.

10. A steam generator unit as claimed in claim 9, wherein the control unit is configured to adjust the power of the heat source to vary the amount of heat energy emitted.

11. A steam generator unit as claimed in claim 9 or 10, wherein the control unit is operable to control the heat source based on detected temperature of contents within the containment structure.

12. A steam generator unit as claimed in any of claims 9 to 11, wherein the control unit is operable to control the heat source based on detected pressure of contents within the containment structure.

13. A steam generator unit as claimed in any of claims 8 to 10, wherein the control unit is configured to open a valve to let water into the containment structure based upon any of: detected water level; detected temperature; detected pressure; amount of consumed steam.

14. A steam generator unit as claimed in claim 11, wherein the heat source extends into a containment region within the containment structure, and the control unit is configured to let the water into the containment structure such that water in the containment structure is replenished and maintained with a water level above the heat source.

15. A steam production system for producing steam in a designated EX Zone or Safe Zone of an oilfield exploration or production facility, the steam production system configured to be connected to facility water and facility electrical power, the steam production system comprising:

a steam generator unit in accordance with any preceding claim; and

at least one pre-heater to pre-heat water to be supplied to the containment structure of the steam generator unit.

P31608NO00

16. A steam production system as claimed in claim 15, wherein the pre-heater comprises at least one electrically operable heat source for pre-heating the water, the heat source configured to be connected to another facility power outlet.

17. A steam production system as claimed in claim 15 or 16, wherein the heat source of either or both the steam generator and the pre-heater device is an electrical heating element.

18. A steam production system as claimed in any of claims 15 to 17, further comprising a pre-processing system including the at least one pre-heater, the pre-heater being or comprising any one or more of:

a first type pre-heater device comprising a large capacity tank for containing water and at least one electrically operable heat source in heat transfer proximity to a water containment region within the large capacity tank for heating the water therein;

a second type pre-heater device comprising a small capacity tank for containing water, and at least one electrically operable heat source in heat transfer proximity to a water containment region within the small capacity tank for heating the water therein;

a third type pre-heater device comprising a pipe section for containing a flow of water therethrough, a heating region within the pipe section, and at least one electrically operable heat source in heat transfer proximity to the heating region for applying heat energy to the water at the heating region.

19. A steam production system as claimed in claim 18, wherein the pre-processing system includes:

at least one large capacity tank for containing heated water; and

at least one second or third type pre-heater device to heat water and coupled to the large capacity tank for conveying heated water to the large capacity tank.

20. A steam production system as claimed in claim 18 or 19, wherein the pre-processing system includes:

a first type pre-heater device arranged between a second or third type pre-heater device and the steam generator unit; or

a large capacity tank for containing heated water, arranged between a second or third type pre-heater device and the steam generator unit;

P31608NO00

for supplying heated water from the second or third type pre-heater device to the first type pre-heater device or the large capacity tank, and therefrom to the steam generator unit.

21. A steam production system as claimed in any of claims 18 to 20, wherein the preprocessing system includes:

a second or third type pre-heater device arranged between a first type pre-heater device and the steam generator; or

a second or third type pre-heater device arranged between a large capacity tank and the steam generator;

for supplying heated water from the first type pre-heater device or the large capacity tank to the second or third type pre-heater device, and therefrom to the steam generator unit.

22. A steam production system as claimed in any of claims 15 to 21, having a first mode for generating steam and a second mode for preparing water, wherein in the second mode an outlet of the steam generator containment structure is opened, and the system is operable for directing water from the pre-processing system into the steam generator containment structure through an inlet, operating the electrical heat source of the steam generator unit to heat the water in the tank, directing heated water out of the steam generator containment structure through the opened outlet back to the pre-processing system.

23. Apparatus for use in the steam production system of any of claims 15 to 22 in the form of a unitary structure including the steam generator unit and either or both of at least one preheater device and at least one tank for containing heated water.

24. Apparatus as claimed in claim 23, including a supporting frame to which the steam generator unit and the pre-heater and/or tank are mounted.

25. Apparatus as claimed in claim 23 or 24, being containerized or configured to be containerized within a shipping container approved for lifting on/off any vessel and between a vessel and an offshore rig/platform facility; or being configured to be supported upon a lifting frame approved for lifting on/off any vessel and between a vessel and an offshore rig/platform facility.

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26. A method of operating the steam production system as claimed in any of claims 15 to 22 on an oilfield exploration of production facility, the steam production system arranged to be supplied with facility water and facility electrical power.

27. A method of producing steam on an oilfield exploration or production facility, the facility to supply facility water and facility electrical power, the method comprising the steps of:

providing a steam generator unit in accordance with any of claims 1 to 14 on the facility; supplying the steam generator unit with water;

containing steam and water in the containment structure of the steam generator unit; and

using the heat source to emit heat energy, thereby to generate steam from the water within the steam generator containment structure.

28. A method as claimed in claim 27, which further comprises pre-heating water, and supplying the containment structure with pre-heated water.

29. A method as claimed in claim 28, which includes first stage pre-heating of water and second stage pre-heating of water.

30. A method as claimed in claim 29, wherein first stage pre-heating of water is performed using at least one pre-heater device and second stage pre-heating of water is performed using at least one further pre-heater device, and the method further comprises:

supplying heated water from the one pre-heater device to the further pre-heater device and

supplying heated water from the further pre-heater device to the steam generator unit.

31. A method as claimed in any of claims 26 to 28, which further comprises outputting steam from the tank of the steam generator unit to perform an operational steam task.

P31608NO00

Drawings

Priority

No priority

Patent classes

IPC classes

F22B 1/28

F22B 33/00

CPC classes

F22B 1/28

F22B 1/284

F22B 33/00

Citations

KR 20180047995 A (A)

CN 108506914 A (A)

Vapormist Electric to Steam Humidifier, Installation Operation and Maintenance Manual, retrieved 01.10.2025, dated 2020 ()

Applicants, owners and inventors

Applicants

Scan Tech AS

Finnestadsvingen 23

4029 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Org. number: 974348128

Inventors

Andreas Fliss

Smietunet 48

4027 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Jone Selbak

Hitraveien 15

4029 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Sindre Søgaard

Staselinveien 20

4326 SANDNES

NO (SANDNES Municipality, Rogaland county)

Andreas Nordstrand

Kjeldesvingen 1

4330 ÅLGÅRD

NO (GJESDAL Municipality, Rogaland county)

Jonny Foldnes

Foldnesvegen 213

5354 STRAUME

NO (ØYGARDEN Municipality, Vestland county)

Agent

HÅMSØ PATENTBYRÅ AS

Postboks 9

4068 STAVANGER

NO (STAVANGER Municipality, Rogaland county)

Org. number: 918752900

Reference: P31608NO00

Status history

Payment history

Oppositions and appeals

No oppositions or appeals

Administrative limitation

No administrative limitation

Liens and licences

No liens or licenses registered

Gazette entries

No Gazette entries found

Only events from 2024.03.04 and onwards are shown.