Fracturing power supply system with well drilling remaining power grid and stored energy jointly loaded

Abstract

The utility model discloses a fracturing power supply system with a well drilling remaining power grid and stored energy jointly loaded, which comprises a reactive compensation SVG (static var generator) device for outputting compensation current to an AC (alternating current) bus I connected with the power grid; the SVR feeder line voltage regulator is connected with the alternating current bus I and the alternating current bus II; the energy storage device is connected to the alternating current bus II through an energy storage converter and an energy storage boosting transformer; and the power supply end of the electrically-driven fracturing equipment is connected with the alternating-current bus II. The utility model can ensure the stability of fracturing power supply and reduce the cost.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas extraction, and in particular relates to a fracturing power supply system that is loaded by a drilling legacy power grid and energy storage. Background Art

[0002] In the fracturing process of oil and gas extraction, under the same construction scale, compared with traditional diesel-driven fracturing, the output power of the electric-driven fracturing skid is increased by 50%, while the noise generated is reduced by 20%.

[0003] However, the promotion of electric fracturing faces many difficulties. The power grids in Shaanxi, Gansu, Ningxia and other places are of poor quality and very unstable.

[0004] Directly connecting the existing power grid to oil and gas fracturing operations is a problem. When the voltage drops below 9.2 kV, fracturing equipment shuts down, causing sand blockage in the wellbore and significant economic losses. The existing power grid capacity, typically 2500-3500 kVA, is too small to support the operation of a single electric drive unit, resulting in limited economic benefits.

[0005] Furthermore, the 10kV dedicated line used during the initial drilling process was only sufficient for drilling operations and could not be used by fracturing equipment. Adding a new 10kV or 35kV dedicated line would face long approval cycles and high costs, making it impossible to meet the needs of electric fracturing and its widespread adoption. Utility Model Content

[0006] In order to overcome the shortcomings of the existing technical methods, the purpose of the utility model is to propose a fracturing power supply system that is jointly loaded by the drilling legacy power grid and energy storage, which can ensure the stability of fracturing power supply and reduce costs.

[0007] To achieve the above objectives, the present invention adopts a technical solution: a fracturing power supply system that is jointly loaded by the drilling legacy power grid and energy storage, comprising:

[0008] The reactive power compensation SVG device outputs the compensation current to the AC bus I connected to the power grid;

[0009] SVR feeder voltage regulator, connecting AC bus I and AC bus II;

[0010] Energy storage device, the energy storage device is connected to AC bus II through an energy storage converter and an energy storage step-up transformer;

[0011] And the electric-driven fracturing equipment, the power supply end is connected to AC bus II.

[0012] Furthermore, the reactive power compensation SVG device includes a detection circuit, a control operator and a compensation output circuit, and the detection circuit, the control operator and the compensation output circuit are electrically connected in sequence.

[0013] Furthermore, a switch 1 is provided on the connection line between the power grid and the AC bus I; a switch 2 is provided on the connection line between the reactive power compensation SVG device and the AC bus I; a switch 3 is provided on the connection line between the SVR feeder voltage regulator and the AC bus II; a switch 4 is provided on the connection line between the electric-driven fracturing equipment and the AC bus II; and a switch 5 is provided on the connection line between the energy storage device and the AC bus II.

[0014] Furthermore, the AC bus II is also connected to basic electrical equipment via a step-down transformer.

[0015] Furthermore, a switch 6 is provided on the connection line between the basic electrical equipment and the AC bus II.

[0016] The beneficial effects of adopting this technical solution are:

[0017] The utility model utilizes the power grid left over from drilling and energy storage to jointly carry the load in the fracturing device to supply power. When not fracturing, the power grid left over from drilling is used to charge the energy storage system. When fracturing is carried out by electric drive, the energy storage is incorporated into the power grid to jointly realize the load of electric drive fracturing and ensure the normal operation of the fracturing device.

[0018] The utility model energy storage system adds an SVG reactive compensation device and an SVR feeder automatic voltage regulator for reactive power compensation. The system's intelligent controller collects, analyzes, judges, processes grid signals, and then issues a signal to drive the on-load tap changer to adjust the voltage. This solves the problem of large voltage fluctuations in 10kV distribution lines due to seasonal and diurnal changes. Using reactive power compensation to improve the system's reactive power can improve the voltage quality at the terminal, further reducing voltage fluctuations that cause load loss and avoiding grid fluctuations. The terminal voltage is stabilized within 10.5-10.8kV, solving the problem of electric fracturing equipment shutdown caused by low grid voltage.

[0019] This utility model can utilize the time-shifting capability of energy storage to capture the difference between peak and valley prices on the power grid. Charging can be performed at night during the valley period and discharging during the peak period during the day, reducing electricity costs for oil and gas fracturing operations, lowering charging costs and minimizing waste of grid resources. In the event of an emergency power outage caused by a line fault or maintenance, the energy storage can be switched on and off the grid, with off-grid operation driving electric fracturing, ensuring wellbore safety and improving the safety of fracturing equipment operations. Real-time adaptation to grid demand helps maintain the supply and demand balance of the power system and ensures the stability of the power system's frequency and voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural schematic diagram of a fracturing power supply system that is loaded by both the drilling legacy power grid and energy storage.

[0021] Figure 2This is a structural diagram of a fracturing power supply system that is jointly loaded by a drilling legacy power grid and energy storage in an optimized embodiment of the present utility model;

[0022] Among them, 1 is the power grid, 2 is the reactive power compensation SVG device, 3 is the SVR feeder voltage regulator, 4 is the AC bus I, 5 is the AC bus II, 6 is the energy storage device, 7 is the energy storage converter, 8 is the energy storage step-up transformer, 9 is the electric-driven fracturing equipment, 10 is switch 1, 11 is switch 2, 12 is switch 3, 13 is switch 4, 14 is switch 5, 15 is switch 6, 16 is the step-down transformer, and 17 is the basic electrical equipment. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the utility model clearer, the utility model is further described below with reference to the accompanying drawings.

[0024] In this embodiment, see Figure 1 As shown, a fracturing power supply system that uses a drilling legacy power grid and energy storage to carry loads, including:

[0025] The reactive power compensation SVG device 2 outputs the compensation current to the AC bus Ⅰ 4 connected to the power grid 1;

[0026] SVR feeder voltage regulator 3, connecting AC bus I4 and AC bus II5;

[0027] Energy storage device 6, which is connected to AC bus II 5 through energy storage converter 7 and energy storage step-up transformer 8; converts DC to 690V AC, which is then converted to 10kV through a transformer;

[0028] And the electric-driven fracturing equipment 9, the power supply end is connected to the AC bus II 5.

[0029] The SVR feeder voltage regulator 3 detects the voltage at the output of the voltage regulator and compares it with the reference voltage. When the voltage at the output of the voltage regulator is higher or lower than the reference value, the motor in the delayed on-load tap changer runs, driving the tap changer to switch from one tap to another, thereby changing the transformation ratio of the autotransformer to achieve on-load automatic voltage regulation.

[0030] As an optimization solution of the above embodiment, the reactive power compensation SVG device 2 includes a detection circuit, a control operator and a compensation output circuit, and the detection circuit, the control operator and the compensation output circuit are electrically connected in sequence.

[0031] The working principle of the reactive power compensation SVG is to obtain the current information provided by the external detection system through the detection circuit, and then analyze the current information, such as PF, S, Q, etc. through the control operator; then the control operator provides a compensation drive signal, and then the compensation output circuit, such as the inverter circuit composed of the power supply electronic inverter circuit, sends out the compensation current.

[0032] As an optimization solution of the above embodiment, a switch 110 is provided on the connection line between the power grid 1 and the AC bus I4; a switch 211 is provided on the connection line between the reactive power compensation SVG device 2 and the AC bus I4; a switch 312 is provided on the connection line between the SVR feeder voltage regulator 3 and the AC bus II5; a switch 413 is provided on the connection line between the electric fracturing equipment 9 and the AC bus II5; and a switch 514 is provided on the connection line between the energy storage device 6 and the AC bus II5.

[0033] When switches 1 / 2 / 3 / 4 / 5 are closed, the displacement and pressure of the electric-driven fracturing device 9 increase, and the power gradually increases. When the power demand is less than the set value, the power is provided by grid 1. When the power demand of the electric-driven fracturing device 9 exceeds the set value, the energy storage device 6 converts the DC power supply to 10kV power through the energy storage converter 7 and the energy storage boost transformer 8, and together with grid 1, it drives the electric-driven fracturing device 9. When the input voltage of grid 1 falls below 10.3kV, the SVR voltage regulator begins to adjust from gear 1 to gear 2, and the output voltage of the voltage regulator increases from 10.3kV to 10.5kV. When the input voltage of grid 1 falls below 10.1kV, the SVR voltage regulator begins to adjust from gear 2 to gear 3, and the output voltage of the voltage regulator increases from 10.1kV to 10.5kV. This process continues for a total of nine gears, with a voltage regulation range of 8.8-10.5kV. When the reactive power of grid 1 exceeds the designed set value, the SVG reactive compensation detects the signal of grid 1 and starts to perform reactive compensation on grid 1.

[0034] When the power grid 1 is out of power, the system control switch 312 is disconnected, and the energy storage converter 7 is switched to the off-grid mode to provide power to the electric-driven fracturing equipment 9 and basic electrical equipment.

[0035] As an optimization solution of the above embodiment, Figure 2 As shown, the AC bus II 5 is also connected to basic electrical equipment via a step-down transformer, making it easy to connect to other basic electrical equipment.

[0036] A switch 615 is provided on the connection line between the basic electrical equipment and the AC bus II5.

[0037] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements are intended to fall within the scope of the present invention. The scope of protection claimed in this invention is defined by the appended claims and their equivalents.

Claims

1. A fracturing power supply system that is jointly loaded by a drilling legacy power grid and energy storage, characterized in that: include: A reactive power compensation SVG device (2) outputs a compensation current to an AC bus I (4) connected to a power grid (1); SVR feeder voltage regulator (3), connecting AC bus I (4) and AC bus II (5); An energy storage device (6), the energy storage device (6) is connected to the AC bus II (5) via an energy storage converter (7) and an energy storage step-up transformer (8); and an electric-driven fracturing device (9), the power supply end of which is connected to the AC busbar II (5).

2. The fracturing power supply system with both drilling legacy power grid and energy storage as claimed in claim 1 is characterized in that: The reactive power compensation SVG device (2) comprises a detection circuit, a control operator and a compensation output circuit, wherein the detection circuit, the control operator and the compensation output circuit are electrically connected in sequence.

3. The fracturing power supply system with both drilling legacy power grid and energy storage as claimed in claim 1 is characterized in that: A switch 1 (10) is provided on the connection line between the power grid (1) and the AC busbar I (4); a switch 2 (11) is provided on the connection line between the reactive power compensation SVG device (2) and the AC busbar I (4); a switch 3 (12) is provided on the connection line between the SVR feeder voltage regulator (3) and the AC busbar II (5); a switch 4 (13) is provided on the connection line between the electric drive fracturing equipment (9) and the AC busbar II (5); and a switch 5 (14) is provided on the connection line between the energy storage device (6) and the AC busbar II (5).

4. The fracturing power supply system with both drilling legacy power grid and energy storage as claimed in claim 1, characterized in that: The AC bus II (5) is also connected to basic electrical equipment via a step-down transformer.

5. The fracturing power supply system with both drilling legacy power grid and energy storage as claimed in claim 4 is characterized in that: A switch 6 (15) is provided on the connection line between the basic electrical equipment and the AC bus II (5).

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