Gravity and electrochemistry hybrid energy storage oil well micro-grid system and energy supply method

Abstract

The invention belongs to the field of oil field well site energy supply, and discloses a gravity and electrochemistry hybrid energy storage oil well micro-grid system and an energy supply method. The system comprises a clean energy power generation device, an energy storage device, a production load, a power distribution device and an energy management device. Wherein the energy storage device comprises gravity energy storage equipment and electrochemical energy storage equipment, and the gravity energy storage equipment is formed by transforming an idle well in a well site. According to the system, the super-generating capacity of wind and light power generation is converted into potential energy to be stored in the gravity energy storage equipment, the gravity energy storage equipment can serve as a long-time energy storage device, when wind and light output is insufficient and the electrochemical energy storage equipment is insufficient in energy supply, the potential energy of the gravity energy storage equipment can be converted into electric energy to supply power to a load, and the energy utilization rate is increased; and the energy supply stability of the system is enhanced. In addition, the gravity energy storage device is formed by transforming an idle well in a well site, and is economical and environmentally friendly.

Description

Technical Field

[0001] This invention relates to the field of energy supply for oilfield well sites, and more particularly to an oil well microgrid system and energy supply method that combines gravity and electrochemical energy storage. Background Technology

[0002] Oilfield mechanical extraction systems are key facilities for oil and gas resource development. Their power supply mainly relies on municipal electricity from the main power grid. However, the current municipal electricity structure is dominated by thermal power, which leads to two main problems: first, high carbon emissions, which are detrimental to global climate change response; and second, high energy costs, which increase the production costs of oilfields. While natural gas, as associated gas from oil wells, reduces power supply costs to some extent, its direct combustion for power generation also results in high carbon emissions, contradicting the goal of green and low-carbon development.

[0003] Given the dual challenges of high energy costs and large carbon emissions currently facing oilfields, academia and industry are exploring innovative solutions. One forward-looking proposal is to introduce and build new energy systems at oilfield well sites as a green alternative to traditional grid power supply. The core of this new energy system lies in fully integrating and utilizing the large amount of idle land resources at oilfield well sites, and deploying green energy supply equipment such as photovoltaic panels and wind turbines according to local conditions.

[0004] For example, patent CN117595271A discloses an energy dispatching method and device for oilfield well sites. The integrated functional model involved includes four parts: a well site new energy microgrid, a power grid, well site loads, and energy storage equipment. This integrated functional model is an energy supply system that uses diesel generators as a supplement and photovoltaic and energy storage as the main components. The well site new energy microgrid is mainly powered by photovoltaic equipment, and the energy storage equipment mainly uses batteries. However, using batteries alone as energy storage equipment has some problems with well site energy supply. For example, the battery capacity affects the reliability and economy of photovoltaic equipment operation to a certain extent. When the battery capacity is relatively small, the load demand during a certain period (such as simultaneous oil production and oil tank electric heating) may not be met; while when the capacity is relatively large, although the reliability of the energy supply system can be improved, the initial construction cost will increase significantly. Moreover, due to the battery capacity limitation, the ability to absorb the electricity generated by photovoltaic equipment is very limited, resulting in a high rate of curtailment and low resource utilization.

[0005] Therefore, it is necessary to improve the current oil well microgrid system to increase its energy utilization efficiency. Summary of the Invention

[0006] To address the above problems, this invention provides an oil well microgrid system and energy supply method that combines gravity and electrochemical energy storage.

[0007] According to one aspect of the present invention, a microgrid system for oil wells that combines gravity and electrochemical energy storage is provided, the system comprising: Clean energy power generation equipment; An energy storage device, comprising a gravity energy storage device and an electrochemical energy storage device, wherein the gravity energy storage device is converted from an idle well at the well site; Production load; A power distribution device, wherein the power distribution device is electrically connected to the clean energy power generation device, the energy storage device and the production load; An energy management device monitors the power generation of the clean energy power generation device, the power consumption of the production load, and the energy storage status of the energy storage device, and controls the operation of the gravity energy storage device based on the power consumption, the power generation, and the energy storage status of the electrochemical energy storage device.

[0008] According to one embodiment of the present invention, the clean energy power generation device includes a photovoltaic power generation device and / or a wind power generation device.

[0009] According to one embodiment of the present invention, the gravity energy storage device includes a motor, a suspension mechanism and a counterweight. The motor is electrically connected to the power distribution device, and the counterweight is connected to the suspension mechanism. The motor can drive the suspension mechanism to change the height of the counterweight in the idle well.

[0010] According to one embodiment of the present invention, the energy management device is configured to control the power distribution device to drive the motor to lift the counterweight when the power generation is higher than the power consumption and the energy storage of the electrochemical energy storage device reaches the upper limit.

[0011] According to one embodiment of the present invention, the energy management device is configured to control the power distribution device to release the counterweight to drive the motor to generate electricity when the power generation is lower than the power consumption and the energy storage of the electrochemical energy storage device reaches a lower limit, thereby supplying power to the production load and / or the electrochemical energy storage device.

[0012] According to one embodiment of the present invention, the photovoltaic power generation device includes a mobile photovoltaic power generation device, which is disposed near the gravity energy storage device.

[0013] According to one embodiment of the present invention, the system further includes a photothermal device that collects heat to heat the oil tank.

[0014] According to one embodiment of the present invention, the system further includes a gas-fired power generation device, which employs a mobile gas generator and utilizes associated gas from the well site to generate electricity.

[0015] According to one embodiment of the present invention, the gas-fired power generation unit generates electricity when the continuous output of the clean energy power generation unit is insufficient or the power consumption of the production load in the well site increases.

[0016] According to one embodiment of the present invention, the production load includes an oil pumping unit and an oil tank electric heating mechanism.

[0017] According to one embodiment of the present invention, the pumping unit is equipped with an intelligent intermittent pumping component, which can collect downhole pressure, temperature and fluid level data around the clock, identify the operating status of the oil well and automatically adjust the start-up and shutdown cycle of the pumping unit in combination with the energy consumption of the well site.

[0018] According to one embodiment of the present invention, the electrochemical energy storage device employs a lithium battery.

[0019] According to one embodiment of the present invention, the system further includes a centralized control mechanism, which stores well site data and a predictive model for predicting the thermal and electrical energy trends of the well site, and the centralized control mechanism is communicatively connected to the energy management device.

[0020] According to one embodiment of the present invention, the well site data includes electrical energy and thermal energy at the well site, as well as downhole pressure, temperature, and fluid level data.

[0021] According to one embodiment of the present invention, the energy management device is configured to transmit well site data to the centralized control mechanism, the centralized control mechanism determines whether the electrical and thermal energy of the well site needs to be adjusted based on the well site data and the prediction model, and sends an adjustment signal to the energy management device if adjustment is required, and the energy management device adjusts the clean energy power generation device, the energy storage device and the production load in the well site based on the adjustment signal.

[0022] According to another aspect of the present invention, an oil well power supply method is provided, which is implemented using the system described in any of the above embodiments and includes the following steps: Determine whether the power generation capacity of the clean energy power generation device meets the power consumption of the production load to achieve a supply-demand balance; While ensuring supply and demand balance, the power generation capacity of the clean energy power generation device is increased and the excess electrical energy is stored in the electrochemical energy storage device; The operation of the gravity energy storage device is adjusted based on the electrochemical energy storage device reaching its storage limit in order to utilize the gravity energy storage device to store the excess electricity; In the event of insufficient power supply, the electrochemical energy storage device can be used to provide power. When the electrochemical energy storage device is insufficient, the gravity energy storage device is used to supply power.

[0023] According to one embodiment of the present invention, adjusting the operation of the gravity energy storage device includes increasing the height of the counterweight of the gravity energy storage device within the well.

[0024] According to one embodiment of the present invention, the method further includes: Before and / or after adjusting the operation of the gravity energy storage device, determine whether the counterweight has reached its highest point. If the counterweight has reached its highest point, stop adjusting the gravity energy storage device.

[0025] According to one embodiment of the present invention, when the counterweight reaches its highest point, the oil tank electric heating mechanism is activated.

[0026] According to one embodiment of the present invention, the method further includes: After power is supplied using the gravity energy storage device, the oil well's liquid level, pressure, and temperature are compared with their respective limit values. If all indicators are within the safe range, the pumping unit's shutdown and operation are adjusted to reduce power consumption. If any indicator exceeds the limit value, an alarm signal is sent to the energy management device, which then starts the gas-fired power generation device based on the alarm signal.

[0027] Due to the adoption of the above technical solutions, the oil well microgrid system and power supply method with gravity and electrochemical hybrid energy storage provided by the present invention have at least one of the following advantages compared with the prior art: The system of the present invention converts the excess power generated by wind and solar power generation into potential energy and stores it in a gravity energy storage device. The gravity energy storage device can serve as a long-term energy storage device. When the output of wind and solar power is insufficient and the power supply of electrochemical energy storage device is insufficient, the potential energy of the gravity energy storage device can be converted into electrical energy to supply power to the load, thereby improving the energy utilization rate and enhancing the stability of the system power supply; The gravity energy storage device is converted from an idle well at the well site, and the counterweight material can be sourced locally. No harmful gases are emitted during use, making it economical and environmentally friendly; The system and method of the present invention optimize the system structure and improve system efficiency, and use an energy management device to match the system power supply with the load operation, ensuring the safety and reliability of power supply to production facilities such as well site pumping units, and improving the electrification rate and clean energy utilization rate. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of an oil well microgrid system with hybrid gravity and electrochemical energy storage according to an embodiment of the present invention; Figure 2A flowchart illustrating a method for supplying energy to oil wells using a microgrid system for oil wells that utilizes a hybrid gravity and electrochemical energy storage according to an embodiment of the present invention; Figure 3 A specific operational example of a power supply scheme when supply and demand are balanced is shown; Figure 4 A specific operational example of a power supply scheme is shown when supply and demand are unbalanced. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] The terms "comprising" and "having," and any variations thereof, used in the specification and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0031] In the description of this invention and the above-described drawings, when an element is referred to as "fixed to," "mounted to," "set on," or "connected to" another element, it can be located directly or indirectly on that other element. For example, when an element is referred to as "connected to" another element, it can be directly or indirectly connected to that other element.

[0032] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] One objective of this invention is to provide an oil well microgrid system that combines gravity and electrochemical energy storage. For example... Figure 1As shown, the system generally includes a clean energy power generation unit 10, an energy storage unit 20, a production load 30, a power distribution unit 40, and an energy management unit 50. The energy storage unit 20 mainly includes a gravity energy storage device 21 and an electrochemical energy storage device 22. The gravity energy storage device 21 is converted from an idle well at the well site. The production load 30 consists of various devices within the well site that consume electrical energy. The power distribution unit 40 is electrically connected to the clean energy power generation unit 10, the energy storage unit 20, and the production load 30. The energy management unit 50 monitors the power generation of the clean energy power generation unit 10, the power consumption of the production load 30, and the energy storage status of the energy storage unit 20 (including the respective energy storage statuses of the gravity energy storage device 21 and the electrochemical energy storage device 22), and controls the operation of the gravity energy storage device 21 based on the power consumption, power generation, and energy storage status of the electrochemical energy storage device 22.

[0034] The oil well microgrid system provided by this invention, which combines gravity and electrochemical energy storage, converts excess power generated by wind and solar power into potential energy stored in a gravity energy storage device. This gravity energy storage device can serve as a long-term energy storage unit. When wind and solar power output is insufficient or the electrochemical energy storage device's power supply is inadequate, the potential energy of the gravity energy storage device can be converted into electrical energy to power the load, improving energy utilization and enhancing the system's power supply stability. The gravity energy storage device is converted from idle wells at the well site, and the counterweight materials can be sourced locally. It does not emit harmful gases during operation, making it economical and environmentally friendly.

[0035] In some embodiments of the present invention, the clean energy power generation device 10 may include a photovoltaic power generation device 11 and / or a wind power generation device 12. The photovoltaic power generation device 11 may further include a fixed photovoltaic power generation device 11 and a mobile photovoltaic power generation device 11. The DC power generated by the fixed photovoltaic power generation device 11 and the mobile photovoltaic power generation device 11 is connected to the DC bus of the power distribution device 40 after being converted from DC to DC voltage.

[0036] In some embodiments, the fixed photovoltaic power generation device 11 can be fixedly installed on long-term idle land or fences at the well site. Long-term idle land refers to idle land that will not be occupied during production and maintenance. In most cases, it is not necessary to dismantle or move the photovoltaic power generation device. The fixed photovoltaic power generation device mainly includes a photovoltaic array panel and a fixed support. The power of the fixed photovoltaic power generation device 11 can be 31.22 kWp. The photovoltaic array panel is the main component of the solar cell, which is formed by multiple solar cell units being encapsulated in series and parallel, and is the power generation device of the solar cell. The photovoltaic array panel is generally installed in a fixed position using a metal support.

[0037] The support structure of the fixed photovoltaic power generation device 11 has relatively low cost, and it does not require complex tracking mechanisms and control systems; therefore, the overall cost of this type of device is low. Moreover, the structure of this device is relatively simple, and it is easy to maintain. Furthermore, the installation process of the fixed photovoltaic power generation device 11 is relatively simple and quick, requiring no complex installation and commissioning procedures.

[0038] In some embodiments, the mobile photovoltaic power generation device 11 is installed on temporarily idle land within the well site using a mobile support frame. Temporarily idle land refers to land within the well site that is not occupied during production but will be occupied during maintenance. The orientation of the photovoltaic panels affects their power generation efficiency. However, the solar altitude angle, the relative position of the sun, and the azimuth of the earth are constantly changing, so the photovoltaic panels need to continuously adjust their orientation and angle to maintain relatively high power generation efficiency. For this purpose, the photovoltaic array panels can be mounted in the bearings of the main support frame using a rotating shaft, thus enabling rotation. Adding the photovoltaic panel rotation function increases the photovoltaic surface area facing the sun. The main support frame is placed directly on the ground and can be dismantled during major and minor maintenance at the well site, effectively increasing the installed capacity of the photovoltaic system. Furthermore, the mobile photovoltaic power generation device 11 can be installed near a gravity energy storage device, and its power output can be 41.76 kWp. Using the mobile photovoltaic power generation device 11 to supply power to the gravity energy storage device nearby reduces power line losses caused by long-distance power transmission, improves energy utilization efficiency, and reduces production costs and carbon emissions.

[0039] The wind power generation device 12 is a device that converts wind energy into electrical energy. Its power generation principle can be simply described as wind driving a wind turbine, which in turn drives a generator to produce electricity. Generally, there are two types of wind turbines: horizontal-axis wind turbines and vertical-axis wind turbines. In a horizontal-axis wind turbine, the turbine shaft is parallel to the horizontal plane, while in a vertical-axis wind turbine, the turbine shaft is perpendicular to the horizontal plane. Horizontal-axis wind turbines are more economical than vertical-axis wind turbines and can be started without the need for external equipment.

[0040] In some embodiments, a small horizontal-axis wind turbine generator with a power of 400kW can be used, and the generated power is connected to the DC bus of the well site power distribution device after AC / DC rectification.

[0041] The energy storage device 20 mainly includes a gravity energy storage device 21 and an electrochemical energy storage device 22 (i.e., a battery).

[0042] Gravity energy storage equipment 21 mainly consists of idle wells at the well site and related gravity energy storage facilities installed in the wells. Idle wells at the well site can refer to the following wells: wells that lack comprehensive utilization potential during oil and gas field development; wells that are difficult to extract oil and gas and are hard to utilize; wells that have lost their production function due to severe casing damage that makes them irreparable; and wells that cannot be utilized due to other special circumstances.

[0043] Given that idle wells often lack further oil and gas extraction value and their existence may pose potential threats to the environment and human safety, it is worthwhile to explore converting such oil and gas wells into components of gravity energy storage and power generation facilities, thus developing new reuse pathways. Moreover, using idle wells as gravity energy storage facilities eliminates the need to construct additional energy storage towers or frames above ground, making it safer and more cost-effective.

[0044] The gravity energy storage device 21 mainly includes a motor, a suspension mechanism, and a counterweight. The counterweight is connected to the bottom of the suspension mechanism, and the motor drives the suspension mechanism to change the height of the counterweight in the idle well. The motor is electrically connected to the power distribution device 40. When the clean energy power generation device 10 generates excess power, the excess power is used to drive the motor of the gravity energy storage device 21 to raise the height of the counterweight in the well, converting the excess power into the gravitational potential energy of the counterweight. The motor can be an asynchronous motor that functions as both a motor and a generator, and it can also be electrically connected to the electrochemical energy storage device 22. When the continuous output of wind and solar power is insufficient (i.e., the continuous output power of wind and solar power fails to meet the expected or power system requirements within a set time period) or when the power of the electrochemical energy storage device 22 is low, the counterweight at the higher position can be released. As the counterweight falls, it drives the motor to rotate and generate electricity. The generated electricity can power production loads such as oil pumps, or it can charge the electrochemical energy storage device 22. The counterweight can be made from locally sourced materials, such as cement blocks, iron blocks, or other dense materials found at the well site. An upper and lower limit position can be set for the counterweight's operation. The upper limit position can be, for example, at or near the wellhead, while the lower limit position can be determined based on the well depth. This lower limit position ensures the counterweight can operate safely and smoothly while releasing as much gravitational potential energy as possible.

[0045] Since the gravity energy storage device 21 releases energy by the falling of a counterweight, the initial velocity of the counterweight is zero during the initial descent, and the counterweight is in the acceleration phase. As the counterweight gradually accelerates, the generator output is not particularly stable. To avoid excessive fluctuations in grid-connected power, grid connection is not performed. After the acceleration phase, once a certain speed is reached, the counterweight is tractioned by an electric motor to maintain a constant speed and begin uniform motion. Grid connection is then performed at this point, which stabilizes the generator's power output and reduces power fluctuations during grid connection.

[0046] In some embodiments, the electrochemical energy storage device 22 includes a battery, specifically a safe and efficient lithium iron phosphate cell, which stores excess electricity generated by wind and solar power and serves as a support power source for the well site. After DC / DC conversion, the battery is connected to the DC power distribution system at the well site to supply power to the oil well's production load. The battery has a rated power of 50kW and a capacity of 110kWh.

[0047] In some embodiments, the production load 30 mainly includes a pumping unit and an electric heating mechanism for the oil tank. The pumping unit may be equipped with an intelligent intermittent pumping component, which can collect downhole pressure, temperature, and fluid level data around the clock, identify the well's operating status, and automatically adjust the pumping unit's start-up and shutdown cycle based on the well site's energy consumption. The pumping unit's rated power can be 37kW. The electric heating mechanism for the oil tank consumes electrical energy to generate heat to heat the oil in the tank.

[0048] In some embodiments, the power distribution unit 40 coordinates and distributes electrical energy from various power generation and energy storage devices, and supplies the electrical energy to various loads in the system. In some embodiments, the power distribution unit 40 is a DC power supply mechanism, which includes a DC bus. The power distribution unit may also include transformers, switching equipment, protection equipment, inverters, etc., to make necessary adjustments and protections to the voltage and current in the power grid, ensuring the stability and safety of power transmission. The well site power distribution unit adopts a DC power supply mechanism, which reduces the investment in the power distribution system, provides flexible control, and can directly supply DC loads such as DC motors. It can also supply AC loads such as AC motors by converting DC / AC to AC.

[0049] In some embodiments, the energy management device 50 of the present invention is used to monitor the power generation of various power generation devices and the energy storage status of the energy storage device 20. For example, it can monitor key parameters such as the power generation, power consumption, energy storage, and equipment efficiency of these devices, and control the power generation of various power generation devices and the energy storage device 20 according to the power consumption of the production load 30 to achieve energy dispatch.

[0050] The energy management device 50 can also intelligently schedule various resources in the system based on real-time monitoring data to achieve wind-solar complementarity and source-load interaction. For example, when wind or solar power is sufficient, renewable energy generation is prioritized; when the load starts up and causes an instantaneous increase in load consumption, if the output power of clean energy such as photovoltaic and wind power is insufficient to provide enough support, the energy management device can further call on gravity energy storage equipment and / or other power generation devices for supplementation.

[0051] Optionally, in some embodiments, the oil well microgrid system of the present invention, which combines gravity and electrochemical energy storage, further includes a solar thermal device / system 60, which can collect heat from light to heat the oil tank. For example, the solar thermal device 60 can employ a high-concentration matrix-type tower-based disc collector system with a power of 45kW. The heat generated is connected to the heating system at the well site, and the tower-based disc collector can be connected to a circulating hot oil system to transport the collected heat to the oil tank and heat the oil therein.

[0052] Optionally, in some embodiments, the oil well microgrid system of the present invention, which combines gravity and electrochemical energy storage, further includes a gas-fired power generation device 70. The gas-fired power generation device 70 can be a mobile gas generator that utilizes associated gas from the well site to generate electricity, with a power output of 50 kWp. In situations where continuous wind and solar power output is insufficient or the well site load increases temporarily, the associated gas from the well site is effectively utilized for power generation. The generated electricity is then converted from AC to DC and connected to the well site DC power distribution device 40.

[0053] Optionally, in some embodiments, the oil well microgrid system of the present invention, which combines gravity and electrochemical energy storage, further includes a centralized control mechanism. The centralized control mechanism stores well site data and a predictive model for forecasting the thermal and electrical energy trends of the well site. The centralized control mechanism is communicatively connected to the energy management device 50. The well site data includes electrical and thermal energy data of the well site, as well as downhole pressure, temperature, and fluid level data. The energy management device 50 is configured to transmit well site data to the centralized control mechanism. Based on the well site data and the predictive model, the centralized control mechanism determines whether adjustments to the electrical and thermal energy of the well site are necessary. If adjustments are required, the centralized control mechanism sends an adjustment signal to the energy management device 50. Based on the adjustment signal, the energy management device 50 adjusts the clean energy power generation device 10, the energy storage device 20, the production load 30, and the optional gas-fired power generation device 70 within the well site.

[0054] Optionally, in some embodiments, the energy management device 50 also has a remote control function, which can receive instructions from the oilfield energy management system and remotely start, stop, and adjust the equipment in the system. At the same time, the energy management device 50 can also wirelessly upload the well site's production information (such as power generation, power consumption, equipment status, etc.) to the oilfield's energy management system to achieve remote monitoring and management.

[0055] In one specific embodiment, the energy management device 50 can adopt a small intelligent microgrid control module based on oil well production. It is low in cost and highly reliable, and can realize power balance and source-load interaction within the grid, ensuring safe energy supply for oil well production.

[0056] Another object of the present invention is to provide an oil well power supply method, which is implemented using the above-mentioned oil well microgrid system with hybrid gravity and electrochemical energy storage. Figure 2The overall flowchart of the method is shown.

[0057] The method begins at step S100, in which the energy management device 50 receives power generation information from the clean energy power generation device 10, receives information on the amount of electricity stored in the energy storage device 20, receives power consumption information from the production load 30, and receives information on pressure, temperature, liquid level, etc. in the well.

[0058] In step S200, the energy management device 50 determines, based on the information collected in step S100, whether the power generation of the clean energy power generation device 10 and the power consumption of the production load 30 meet the supply-demand balance (i.e., the generated electricity matches the consumed electricity). The power consumption of the production load 30 mainly comes from the operation of the oil pumping unit and the operation of the oil tank electric heating mechanism. If the supply-demand balance is met, proceed to step S300. Otherwise, proceed to step S400.

[0059] In step S300, the power generation capacity of the clean energy power generation device 10 is adjusted and the excess electrical energy is stored in the electrochemical energy storage device 22. For example, the power generation capacity of the photovoltaic power generation device 11 and / or the wind power generation device 12 can be increased and the excess electrical energy can be stored in the battery.

[0060] Next, in step S310, it is determined whether the stored capacity of the electrochemical energy storage device 22 has reached the storage limit. If the stored capacity of the electrochemical energy storage device 22 has reached the storage limit, proceed to step S320. If the stored capacity of the electrochemical energy storage device 22 has not reached the storage limit, return to step S300.

[0061] In step S320, the operation of gravity energy storage device 21 is adjusted to store the excess electricity. Further details regarding the power supply scheme when supply and demand are balanced will be discussed later. Figure 3 Please provide an explanation.

[0062] If the supply and demand balance is not met and the power supply is insufficient (i.e., the continuous output power of wind power and / or photovoltaic power generation fails to meet the expected or the needs of the power system), proceed to step S400. In step S400, power is supplied using the electrochemical energy storage device 22.

[0063] When using electrochemical energy storage device 22 for power supply, in step S500, it is further determined whether the electrical energy of electrochemical energy storage device 22 is sufficient, or whether the power supply is insufficient due to insufficient electrical energy in the electrochemical energy storage device 22 itself or due to the continuous consumption of its stored electrical energy. For example, the remaining electrical energy of electrochemical energy storage device 22 can be compared with a predetermined lower limit value, which is the minimum electrical energy required to ensure production safety and equipment safety. When the remaining electrical energy is lower than the predetermined lower limit value, it is considered that the electrical energy of electrochemical energy storage device 22 is insufficient. In this case, proceed to step S600. If the electrical energy of electrochemical energy storage device 22 is sufficient, return to step S400. In step S600, gravity energy storage device 21 can be operated to supply power to the load and / or charge electrochemical energy storage device 22, and the power consumption of production load 30 can be further adjusted. The specific power supply scheme will be combined with... Figure 4 Please provide an explanation.

[0064] Next, in step S700, the adjustment is complete.

[0065] Figure 3 This illustrates a specific operational example of a power supply scheme when supply and demand are balanced.

[0066] If the supply and demand are in balance, proceed to step S300, which can be further divided into two sub-steps, namely step S301 and step S302.

[0067] In step S301, it is first determined whether the power generation of the photovoltaic power generation device 11 and the wind power generation device 12 has reached the upper limit threshold. If the power generation has not reached the upper limit threshold, it indicates that the photovoltaic power generation device 11 and the wind power generation device 12 are in a limited output state, and there is room for further improvement in their power generation.

[0068] When the power generation capacity of the photovoltaic power generation device 11 and the wind power generation device 12 has reached the upper limit threshold, there is no room for further increase in power generation capacity, and the process proceeds to step S370. In step S370, no adjustment is made to the power generation capacity of the photovoltaic power generation device 11 and the wind power generation device 12, i.e., the adjustment ends.

[0069] When the power generation capacity of the photovoltaic power generation device 11 and the wind power generation device 12 does not reach the upper limit threshold, proceed to step S302. In step S302, the power generation capacity of the photovoltaic power generation device 11 and / or the wind power generation device 12 is increased to provide more electrical energy to the electrochemical energy storage device 22. Next, proceed to step S310.

[0070] In step S310, it is determined whether the stored energy of the electrochemical energy storage device 22 has reached the upper limit of electrical energy storage. If the upper limit of electrical energy storage has been reached, proceed to step S320. If the upper limit of electrical energy storage has not been reached, return to step S302.

[0071] In step S320, the operation of the gravity energy storage device 21 is adjusted to store the excess electricity generated. For example, the height of the counterweight of the gravity energy storage device 21 within the well can be increased. Next, proceed to step S330.

[0072] In step S330, it is determined whether the gravity energy storage device 21 has reached its energy storage limit. For example, it can be determined whether the counterweight of the gravity energy storage device 21 has been raised to the vicinity of the wellhead. If the gravity energy storage device 21 has reached its energy storage limit, proceed to step S340. If it has not reached its energy storage limit, return to step S320.

[0073] In step S340, the oil tank electric heating mechanism is activated to consume the excess electricity. Next, proceed to step S350.

[0074] In step S350, it is determined whether the oil tank temperature has reached the peak value. If the oil tank temperature has not reached the peak value, the process returns to step S340 to continue operating the oil tank electric heating mechanism. When the oil tank temperature reaches the peak value, the process proceeds to step S360.

[0075] In step S360, the photovoltaic power generation device 11 and / or the wind power generation device 12 are controlled to perform power curtailment. Next, proceed to step S370, and the adjustment ends.

[0076] Figure 4 This illustrates a specific operational example of a power supply scheme when supply and demand are unbalanced, which generally corresponds to... Figure 2 Steps S400 to S700 of the method shown.

[0077] When supply and demand are unbalanced and the power generation capacity of clean energy cannot meet the power consumption requirements of production load, in step S400, the electrochemical energy storage device 22 is used to supply power.

[0078] In step S410, the electrical energy stored in the electrochemical energy storage device 22 is compared with a lower limit value. If the stored electrical energy is lower than the lower limit value, it indicates that the electrical energy stored in the electrochemical energy storage device 22 may be insufficient to support the continuous operation of loads such as oil pumping units. When the electrical energy stored in the electrochemical energy storage device 22 is lower than the lower limit value, proceed to step S420. Otherwise, return to step S400.

[0079] In step S420, the gravity energy storage device 21 is operated to supply power to the load and / or charge the electrochemical energy storage device 22. For example, a counterweight at a high position can be released and allowed to fall into the well. The falling counterweight drives a generator to generate electricity, which can be used to drive the pumping unit, drive the electric heating mechanism of the oil tank for heating (if needed), or charge the electrochemical energy storage device 22.

[0080] Next, in step S430, it is determined whether the gravity energy storage device 21 has reached its lower energy storage limit, that is, whether the counterweight of the gravity energy storage device 21 has fallen to its lowest position. If the gravity energy storage device 21 has reached its lower energy storage limit, proceed to step S440; otherwise, return to step S420.

[0081] In step S440, the oil well's liquid level, pressure, and temperature are compared with their respective limit values. If all indicators are within the safe range, proceed to step S450. If any one of the indicators exceeds the safe limit value, proceed to step S460.

[0082] In step S450, the intelligent intermittent pumping equipment is activated to adjust the shutdown and operation of the pumping unit to reduce its power consumption. Next, in step S470, the adjustment is completed.

[0083] In step S460, an alarm signal is sent to the energy management device 50, which then activates the gas-fired power generation unit 70 based on the alarm signal, thereby providing additional power to the power grid. Next, in step S470, the adjustment is completed.

[0084] Optionally, in some embodiments, the energy storage device 20 can also be used to power the oil tank electric heating mechanism. In this embodiment, in step S800, the solar thermal device 60 is preferentially used to heat the oil tank. For example, the solar thermal device 60 can be a high-concentration matrix tower-based disc collector system, and the heat generated is connected to the heating system of the well site. The tower-based disc collector can be connected to the circulating hot oil system so as to transport the collected heat to the oil tank and heat the oil therein. Further, in step S810, it is detected whether the oil tank temperature is lower than the lower limit value. If the oil tank temperature is lower than the lower limit value, the oil tank electric heating mechanism is activated in step S820 to heat the oil tank. The oil tank electric heating mechanism preferentially uses the electrical energy in the electrochemical energy storage device 22. If the electrical energy stored in the electrochemical energy storage device 22 is lower than the lower limit value, the gravity energy storage device 21 generates electricity to power the oil tank electric heating mechanism. In step S830, it is determined again whether the oil tank temperature is still below the lower limit. If the oil tank temperature is still below the lower limit, proceed to step S840. If the oil tank temperature is above the lower limit, in step S850, the oil tank electric heating mechanism can be paused and awaited for the next start-up. In step S840, it is determined whether the gravity energy storage device 21 has reached the lower limit of energy storage. If the gravity energy storage device 21 has not reached the lower limit of energy storage, return to step S820; otherwise, proceed to step S460.

[0085] As described above, in step S460, an alarm signal is sent to the energy management device 50, which then activates the gas-fired power generation unit 70 based on the alarm signal, thereby providing additional power to the power grid. When the power supply is sufficient, the oil tank electric heating mechanism is activated again to heat the oil tank. Next, in step S470, the adjustment is completed.

[0086] The system and method of the present invention optimize the system structure and improve system efficiency, and use an energy management device to match the energy supply system with the load operation, thereby ensuring the safe and reliable power supply to production facilities such as well pumping units, and improving the electrification rate and clean energy utilization rate.

[0087] The embodiments described above are merely illustrative of implementation methods of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A microgrid system for oil wells that combines gravity and electrochemical energy storage, characterized in that, include: Clean energy power generation equipment; An energy storage device, comprising a gravity energy storage device and an electrochemical energy storage device, wherein the gravity energy storage device is converted from an idle well at the well site; Production load; A power distribution device, wherein the power distribution device is electrically connected to the clean energy power generation device, the energy storage device and the production load; An energy management device monitors the power generation of the clean energy power generation device, the power consumption of the production load, and the energy storage status of the energy storage device, and controls the operation of the gravity energy storage device based on the power consumption, the power generation, and the energy storage status of the electrochemical energy storage device.

2. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The clean energy power generation devices include photovoltaic power generation devices and / or wind power generation devices.

3. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The gravity energy storage device includes a motor, a suspension mechanism, and a counterweight. The motor is electrically connected to the power distribution device, and the counterweight is connected to the suspension mechanism. The motor can drive the suspension mechanism to change the height of the counterweight in the idle well.

4. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 3, characterized in that, The energy management device is configured to control the power distribution device to drive the motor to lift the counterweight when the power generation is higher than the power consumption and the energy storage of the electrochemical energy storage device reaches the upper limit.

5. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 3, characterized in that, The energy management device is configured to control the power distribution device to release the counterweight to drive the motor to generate electricity when the power generation is lower than the power consumption and the energy storage of the electrochemical energy storage device reaches the lower limit, thereby supplying power to the production load and / or the electrochemical energy storage device.

6. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 2, characterized in that, The photovoltaic power generation device includes a mobile photovoltaic power generation device, which is located near the gravity energy storage device.

7. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The system also includes a photothermal device that collects heat to heat the oil tank.

8. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The system also includes a gas-fired power generation unit, which is a mobile gas generator that uses associated gas from the well site to generate electricity.

9. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 8, characterized in that, The gas-fired power generation unit generates electricity when the continuous output of the clean energy power generation unit is insufficient or when the power consumption of the production load in the well site increases.

10. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 8, characterized in that, The production load includes the oil pumping unit and the electric heating mechanism for the oil tank.

11. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 10, characterized in that, The pumping unit is equipped with an intelligent intermittent pumping component, which can collect downhole pressure, temperature and fluid level data around the clock, identify the operating status of the oil well and automatically adjust the start-up and shutdown cycle of the pumping unit in combination with the energy consumption of the well site.

12. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The electrochemical energy storage device uses lithium batteries.

13. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 1, characterized in that, The system also includes a centralized control mechanism, which stores well site data and predictive models for predicting the thermal and electrical energy trends of the well site. The centralized control mechanism is communicatively connected to the energy management device.

14. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 13, characterized in that, The well site data includes electrical and thermal energy data at the well site, as well as downhole pressure, temperature, and fluid level data.

15. The oil well microgrid system with gravity and electrochemical hybrid energy storage according to claim 14, characterized in that, The energy management device is configured to transmit well site data to the centralized control mechanism. The centralized control mechanism determines whether the electrical and thermal energy of the well site needs to be adjusted based on the well site data and the prediction model. If adjustment is required, the centralized control mechanism sends an adjustment signal to the energy management device. The energy management device adjusts the clean energy power generation device, the energy storage device, and the production load within the well site based on the adjustment signal.

16. A method for supplying energy to oil wells, characterized in that, The method is implemented using the system according to any one of claims 1-15 and includes the following steps: Determine whether the power generation capacity of the clean energy power generation device meets the power consumption of the production load to achieve a supply-demand balance; While ensuring supply and demand balance, the power generation capacity of the clean energy power generation device is increased and the excess electrical energy is stored in the electrochemical energy storage device; The operation of the gravity energy storage device is adjusted based on the electrochemical energy storage device reaching its storage limit in order to utilize the gravity energy storage device to store the excess electricity; In the event of insufficient power supply, the electrochemical energy storage device can be used to provide power. When the electrochemical energy storage device is insufficient, the gravity energy storage device is used to supply power.

17. The method according to claim 16, characterized in that, Adjusting the operation of the gravity energy storage device includes increasing the height of the counterweight of the gravity energy storage device inside the well.

18. The method according to claim 17, characterized in that, Further includes: Before and / or after adjusting the operation of the gravity energy storage device, determine whether the counterweight has reached its highest point. If the counterweight has reached its highest point, stop adjusting the gravity energy storage device.

19. The method according to claim 18, characterized in that, When the counterweight reaches its highest point, the oil tank electric heating mechanism is activated.

20. The method according to claim 16, characterized in that, include: After power is supplied using the gravity energy storage device, the oil well's liquid level, pressure, and temperature are compared with their respective limit values. If all indicators are within the safe range, the pumping unit's shutdown and operation are adjusted to reduce power consumption. If any indicator exceeds the limit value, an alarm signal is sent to the energy management device, which then starts the gas-fired power generation device based on the alarm signal.

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