Control method and system for electric drive fracturing unit

Abstract

The embodiments of the present invention belong to the technical field of fracturing. Provided are a control method and system for an electric drive fracturing unit. The control method for an electric drive fracturing unit comprises: in response to a drive control instruction for an electric drive fracturing unit, reading currently set target parameters; on the basis of the target parameters, calculating a displacement allocation rule for each electric drive fracturing machine, and on the basis of the displacement allocation rule, generating a stepwise control scheme for each electric drive fracturing machine; executing the stepwise control scheme for each electric drive fracturing machine, and during execution, monitoring real-time downhole pressure in real time; determining whether the real-time downhole pressure is not less than a preset protection pressure, and when the real-time downhole pressure is not less than the preset protection pressure, triggering a corresponding protection rule; and on the basis of the corresponding protection rule, executing a corresponding protection scheme until the electric drive fracturing unit reaches the currently set target parameters or target parameters corresponding to the protection rule. The solution of the present invention solves the problems of high difficulty in coordinated control and high difficulty in precise control in existing control solutions for electric drive fracturing units.

Description

Control methods and systems for electric fracturing units

[0001] Cross-reference to related applications

[0002] This application claims the benefit of Chinese Patent Application No. 202411191587.9, filed on August 28, 2024, the contents of which are incorporated herein by reference. Technical Field

[0003] This invention relates to the field of fracturing technology, specifically to a control method and control system for an electric fracturing unit. Background Technology

[0004] Horizontal well volumetric fracturing is now widely used, with fracturing operations involving "tens of thousands of cubic meters of fluid and thousands of cubic meters of sand" becoming the norm. The Huanmahu area and Jimsar shale oilfield in Xinjiang Oilfield are two large oilfields with reserves exceeding 1 billion tons discovered in recent years. To maximize production capacity in the shortest possible time, Xinjiang Oilfield has adopted the bridge plug perforation process for reservoir stimulation operations in both the Huanmahu area and the Jimsar shale oilfield. Due to factors such as improving on-site stimulation efficiency and reducing single-well operating costs, current horizontal well reservoir stimulation work employs factory-style, zipper-like fracturing operations. "Long cycle, large fluid volume, and fast pace" are among the most significant characteristics of factory-style horizontal well fracturing operations. How to reduce operating costs, shorten the construction cycle, improve personnel and equipment efficiency, and ensure personnel and equipment safety has become a challenge for subsequent horizontal well fracturing operations. Therefore, research on self-cruising control methods for electrically driven fracturing units is of great significance for improving operator efficiency and operational quality, reducing construction costs, and ensuring equipment and personnel safety.

[0005] With the gradual development of unconventional oil and gas reservoirs in China and the continuous advancement of energy conservation and emission reduction efforts, electric fracturing has developed. However, as the scale of fracturing continues to expand, traditional control methods are gradually failing to meet the actual needs of large-scale fracturing operations. This is mainly manifested in the difficulty of coordinated operation due to the large number of devices, as well as high construction risks, difficulty in precise control, and poor emergency response capabilities. To address these issues, a new control scheme for electric fracturing units needs to be proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a control method and system for an electric fracturing unit, so as to at least solve the problems of high difficulty in coordinated operation and high difficulty in precise operation of existing electric fracturing unit control schemes.

[0007] To achieve the above objectives, a first aspect of the present invention provides a control method for an electrically driven fracturing unit, the method comprising: responding to a drive control command for the electrically driven fracturing unit and reading currently set target parameters; calculating a displacement allocation rule for each electrically driven fracturing unit based on the target parameters, and generating a stepped control scheme for each electrically driven fracturing unit based on the displacement allocation rule; executing the stepped control scheme for each electrically driven fracturing unit, and monitoring the real-time pressure in the well during execution; determining whether the real-time pressure in the well is not less than a preset protection pressure, and triggering a corresponding protection rule when it is not less than the preset protection pressure; executing a corresponding protection scheme based on the corresponding protection rule until the electrically driven fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

[0008] Optionally, the target parameters include: displacement increase / decrease step size, target displacement holding time, and target displacement.

[0009] Optionally, the step of calculating the displacement allocation rules for each electrically driven fracturing machine based on the target parameters includes: collecting the design displacement threshold of each electrically driven fracturing machine, the total usage time of each electrically driven fracturing machine and each preset vulnerable component, and the usage time of each electrically driven fracturing machine since its most recent start-up; assigning values ​​to the design displacement threshold of each electrically driven fracturing machine, the total usage time of each electrically driven fracturing machine and each preset vulnerable component, and the usage time of each electrically driven fracturing machine since its most recent start-up, respectively, based on the nine-foot calibration method, to obtain corresponding assignment indicators; performing a weighted summation operation on the assignment indicators of each electrically driven fracturing machine based on the preset weights corresponding to each assignment indicator, to obtain the displacement allocation score of each electrically driven fracturing machine; performing displacement allocation for each electrically driven fracturing machine based on the displacement allocation score and the target displacement, to obtain the target displacement of each electrically driven fracturing machine; and calculating the displacement allocation rules for each electrically driven fracturing machine based on the target displacement, displacement increase / decrease step size, and target displacement holding time.

[0010] Optionally, the calculation rule for the displacement allocation rule of each electrically driven fracturing machine is as follows:

[0011] Among them, Q i S represents the target displacement of the i-th electrically driven fracturing unit; i S represents the displacement allocation score for the i-th electrically driven fracturing machine; j Let Q be the displacement allocation score for the j-th electric fracturing machine; n is the number of electric fracturing machines; Q total This is the total target displacement.

[0012] Optionally, the allocation rule for the displacement allocation score of the i-th electrically driven fracturing unit is as follows: S i =ω1*X i +ω2*Y i +ω3*Z i

[0013] Among them, X i Assign a value to the design displacement threshold of the i-th electrically driven fracturing machine; Y i Assign a value to the total service time of the corresponding preset vulnerable parts for the i-th electrically driven fracturing machine; Z i ω1, ω2, and ω3 are the amplitudes of the usage time of the i-th electrically driven fracturing machine since its most recent start-up; ω1, ω2, and ω3 are preset weights.

[0014] Optionally, the calculation of the displacement allocation rule for each electric fracturing machine based on the target displacement, displacement increase / decrease step size, and target displacement holding time of each electric fracturing machine includes: determining the stepped increase / decrease step size of each electric fracturing machine based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding current electric fracturing machine; generating the expected displacement of each electric fracturing machine at each moment based on the stepped increase / decrease step size and target displacement holding time of each electric fracturing machine, as the displacement allocation rule for each electric fracturing machine.

[0015] Optionally, the rule for determining the stepped rise / fall step size of each electric fracturing machine, based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding current electric fracturing machine, is as follows:

[0016] Where, ΔQ i Q represents the stepped lifting / lowering step size of the i-th electrically driven fracturing machine; target,t Let Q be the target displacement of the i-th electrically driven fracturing unit; current,t N represents the current real-time displacement of the i-th electrically driven fracturing unit; i Let be the step number of the i-th electrically driven fracturing machine; the rule for determining the expected displacement of each electrically driven fracturing machine at each moment, based on the step-like rise / fall step size and target displacement holding time, is as follows: Q expected,i(t) =Q current,t +k*ΔQ i

[0017] Among them, Q expected,i(t) Let be the expected displacement of the i-th electrically driven fracturing machine at time t; k is the current ladder number.

[0018] Optionally, generating a stepped control scheme for each electric fracturing machine based on the displacement allocation rule includes: generating a control timing table for each electric fracturing machine based on the expected displacement of each electric fracturing machine at each time moment, as a stepped control scheme for each electric fracturing machine.

[0019] Optionally, the method further includes: when the preset protection pressure is not reached, continuously executing the displacement control of each electric fracturing machine based on the stepped control scheme of each electric fracturing machine; when each electric fracturing machine reaches the corresponding stepped displacement, holding the timer, and executing the next step control when the timer reaches the preset time, until the target displacement of each electric fracturing machine is reached.

[0020] Optionally, the preset protection pressure includes multiple preset protection pressures, with different pressure thresholds for each preset protection pressure.

[0021] Optionally, the protection rules for each preset protection pressure can be the same or different; the protection rules for each preset protection pressure can be any one of maintaining discharge volume, reducing discharge volume, and stopping the pump.

[0022] Optionally, the corresponding protection scheme executed based on the corresponding protection rule, until the electric fracturing unit reaches the currently set target parameter or the target parameter corresponding to the protection rule, includes: if the protection scheme corresponding to the current protection rule is to maintain the discharge rate, determining a preset discharge rate maintenance time, and executing discharge rate maintenance for each electric fracturing unit based on the preset discharge rate maintenance time; if the protection scheme corresponding to the current protection rule is to reduce the discharge rate, determining the discharge rate reduction amount, discharge rate reduction step, and target discharge rate maintenance time based on the difference between the real-time pressure in the well and the pressure threshold of the corresponding level preset protection pressure, and executing control of each electric fracturing unit based on the determined discharge rate reduction amount, discharge rate reduction step, and target discharge rate maintenance time; if the protection scheme corresponding to the current protection rule is to stop the pump, controlling each electric fracturing unit to stop working.

[0023] A second aspect of the present invention provides a control system for an electrically driven fracturing unit, the system comprising:

[0024] The system comprises the following components: a data acquisition unit, which responds to drive control commands from the electric fracturing unit and reads the currently set target parameters; a scheme generation unit, which calculates the displacement allocation rules for each electric fracturing unit based on the target parameters and generates a stepped control scheme for each electric fracturing unit based on the displacement allocation rules; a monitoring unit, which executes the stepped control scheme for each electric fracturing unit and monitors the real-time pressure inside the well during execution; a judgment unit, which judges whether the real-time pressure inside the well is not less than the preset protection pressure and triggers the corresponding protection rule when it is not less than the preset protection pressure; and an execution unit, which executes the corresponding protection scheme based on the corresponding protection rule until the electric fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

[0025] On the other hand, the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described electric fracturing unit control method.

[0026] Through the above technical solution, the present invention achieves automatic control of each electrically driven fracturing press by specifying user parameters. When generating the control scheme, the displacement allocation rules for each electrically driven fracturing press are calculated based on the target parameters, and a stepped control scheme for each press is generated based on these rules. This eliminates the need for individual user control, achieving coordinated control of the entire unit, reducing reliance on manual experience, ensuring control accuracy, and solving the problems of high difficulty in coordinated and precise operation in existing electrically driven fracturing unit control schemes.

[0027] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0028] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0029] Figure 1 is a flowchart of the steps of an electric fracturing unit control method provided in one embodiment of the present invention;

[0030] Figure 2 is a control process diagram of a stepped control scheme for an electrically driven fracturing machine provided in one embodiment of the present invention.

[0031] Figure 3 is a system structure diagram of the control system of an electric fracturing unit provided in one embodiment of the present invention. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0033] Fracturing pump trucks / skids are key supporting equipment for oilfield fracturing and sand control operations. They are specialized equipment used to inject high-pressure, high-volume fracturing fluids into wells to break up formations and force proppant into fractures. The equipment can operate as a standalone unit or in multiple units. With the gradual development of unconventional oil and gas reservoirs in China and the continuous advancement of energy conservation and emission reduction efforts, domestic fracturing equipment manufacturers have shifted towards the field of electric fracturing equipment manufacturing. Each manufacturer has its own self-developed electric fracturing control system, which can basically achieve automatic control of electric fracturing units. However, with the continuous expansion of fracturing scale, traditional control methods are gradually failing to meet the actual needs of large-scale fracturing operations, mainly in the following aspects:

[0034] 1. Large number of equipment and high difficulty in coordinated operation: Traditional fracturing operations involve 8-12 fracturing units, which can be operated by one person. However, with the increasing scale of unconventional oil and gas reservoir development, the demand for fracturing units at fracturing sites is also constantly increasing. For example, in 2023, at Sinopec's Xingye 7LHF well, 26 fracturing units were involved in the on-site operation, with a maximum operating displacement of 24.5 m³ / h. 3 / min, in actual operation, it often requires 2 to 3 fracturing equipment operators to operate in coordination, and the coordinated operation of fracturing units is quite difficult.

[0035] 2. High construction risk and difficulty in precise control: During the fracturing operation of unconventional oil and gas reservoirs, due to geological factors such as the heterogeneity and low permeability of unconventional reservoirs, as well as engineering factors such as downhole bridge plug displacement, casing deformation, and sand blockage, the on-site electric fracturing unit needs to be able to respond quickly according to the operating pressure to ensure the safety and sustainability of the fracturing operation. However, at present, the control commands of fracturing equipment are all manually implemented by the operators, making it difficult to achieve rapid and precise control of the electric fracturing unit.

[0036] 3. Poor emergency response capability: Traditional electric fracturing units only have one way to deal with construction pressure exceeding the safety limit: overpressure reset. In actual construction, operators group the electric fracturing units according to different safety limit levels to set overpressure safety settings to ensure construction safety. However, under this method, the discharge volume during construction will fluctuate drastically, which will generate a "water hammer effect" inside the high-pressure pipeline and have a certain impact on the safe production of fracturing operations.

[0037] The purpose of this invention is to provide a control method for an electrically driven fracturing unit, which enables centralized control of multiple electrically driven fracturing units. By setting relevant necessary parameters in the setting interface of the electrically driven fracturing unit control system and combining iterative upgrades of the programmable logic controller (PLC) automatic control program, the method achieves platform control of the electrically driven fracturing unit, safe adjustment of output displacement, and gradient safety control protection for the unit. This ensures the safety, stability, and continuity of fracturing operations, thereby guaranteeing the efficient development and rapid production of unconventional oil and gas reservoirs.

[0038] Figure 1 is a flowchart of a method for controlling an electrically driven fracturing unit according to an embodiment of the present invention. As shown in Figure 1, an embodiment of the present invention provides a method for controlling an electrically driven fracturing unit, the method comprising:

[0039] Step S10: Respond to the drive control command of the electric fracturing unit and read the currently set target parameters.

[0040] Specifically, the target parameters include: displacement increase / decrease step size, target displacement holding time, and target displacement.

[0041] In this embodiment of the invention, the solution aims to achieve coordinated control of the entire electrically driven fracturing unit based on user-defined parameters, and correspondingly adds a user parameter specification function. The user sets target parameters based on fracturing requirements, and the entire unit will be automatically controlled based on these user-defined target parameters, thereby achieving safety, stability, and continuity in fracturing operations.

[0042] In one possible implementation, an intuitive and user-friendly interface is developed, including a parameter setting page and a real-time monitoring page, enabling users to easily set target parameters and monitor the unit's operating status in real time. Parameter adjustment buttons and input boxes are provided, allowing users to set parameters such as displacement increase / decrease step size and target displacement hold time, while simultaneously displaying current parameter values ​​and setting status. A parameter parsing algorithm is designed to convert the user-set target parameters into control commands, ensuring the accuracy and reliability of parameter transmission. The user-set parameters are transmitted to the electric fracturing unit's control system via a communication module, achieving real-time parameter updates and synchronization. The operating status of the PLC control system is adjusted according to the user-set target parameters, achieving precise control of the displacement increase / decrease step size and target displacement. Combining real-time data feedback and system status monitoring, the control strategy is dynamically adjusted to ensure the unit operates in its optimal working condition.

[0043] Step S20: Calculate the displacement allocation rule for each electric fracturing machine based on the target parameters, and generate a step-by-step control scheme for each electric fracturing machine based on the displacement allocation rule.

[0044] Specifically, the calculation of the displacement allocation rules for each electrically driven fracturing machine based on the target parameters includes: collecting the design displacement threshold of each electrically driven fracturing machine, the total usage time of each electrically driven fracturing machine and each preset vulnerable component, and the usage time of each electrically driven fracturing machine since its most recent start-up; assigning values ​​to the design displacement threshold of each electrically driven fracturing machine, the total usage time of each electrically driven fracturing machine and each preset vulnerable component, and the usage time of each electrically driven fracturing machine since its most recent start-up, respectively, based on the nine-foot calibration method, to obtain corresponding assignment indicators; performing a weighted summation operation on the assignment indicators of each electrically driven fracturing machine based on the preset weights corresponding to each assignment indicator, to obtain the displacement allocation score of each electrically driven fracturing machine; performing displacement allocation for each electrically driven fracturing machine based on the displacement allocation score and the target displacement, to obtain the target displacement of each electrically driven fracturing machine; and calculating the displacement allocation rules for each electrically driven fracturing machine based on the target displacement, displacement increase / decrease step size, and target displacement holding time.

[0045] In this embodiment of the invention, the design displacement threshold of each electrically driven fracturing machine is monitored by preset parameters, and the data is transmitted to the control system. The total usage time and the usage time since the most recent start-up of each electrically driven fracturing machine and each preset vulnerable component are recorded to evaluate the operating status and stability of the equipment. The design displacement threshold, total usage time, and usage time since the most recent start-up are assigned values ​​according to the nine-foot scale method, resulting in corresponding assigned indices used for subsequent weighted summation calculations. The longer the total service life, the lower the corresponding assigned value, so that the service life of each fracturing machine is balanced as much as possible during subsequent control processes, avoiding overuse of a single machine leading to failure. Similarly, the longer the usage time since the most recent start-up, the lower the corresponding assigned value, so that idle equipment is utilized as much as possible, avoiding prolonged operation of a single machine and balancing the working time of each machine. This invention's solution achieves intelligent displacement allocation by balancing the usage of each machine, rather than solely allocating based on the design displacement of each machine, thereby reducing the occurrence of failures and providing system operational stability.

[0046] Furthermore, preset weights are assigned to each assigned indicator to reflect its importance in displacement allocation. Based on the assigned values ​​and corresponding preset weights of each indicator, a weighted summation operation is performed to obtain the displacement allocation score for each electrically driven fracturing machine, which is used to determine the priority of displacement allocation. Based on the user-defined target displacement and the flow allocation score of each electrically driven fracturing machine, the target displacement of each machine is determined to achieve reasonable flow allocation. Combining the target displacement, displacement increase / decrease step size, and target displacement holding time, the displacement allocation rules for each electrically driven fracturing machine are calculated to ensure stable adjustment and maintenance of displacement during construction. Based on this invention, through weighted summation and flow allocation score calculation, the flow allocation of each electrically driven fracturing machine is optimized, improving construction efficiency and resource utilization. According to the displacement allocation rules and target displacement settings, precise control of the displacement of each electrically driven fracturing machine is achieved, ensuring stability and continuity during construction. Based on the calculated displacement allocation rules and target displacement, the system enables automated adjustment of the electric fracturing unit, reducing human intervention and improving operational efficiency and accuracy. Combined with a real-time data acquisition and monitoring system, it provides timely feedback on the operating status and parameter changes of each electric fracturing unit, helping users to adjust and optimize the construction process in real time.

[0047] Specifically, the calculation rule for the displacement allocation of each electrically driven fracturing machine is as follows:

[0048] Among them, Q i S represents the target displacement of the i-th electrically driven fracturing unit; i S represents the displacement allocation score for the i-th electrically driven fracturing machine; j Let Q be the displacement allocation score for the j-th electric fracturing machine; n is the number of electric fracturing machines; Q total This is the total target displacement.

[0049] The allocation rule for the displacement distribution score of the i-th electrically driven fracturing machine is as follows: S i =ω1*X i +ω2*Y i +ω3*Z i

[0050] Among them, X i Assign a value to the design displacement threshold of the i-th electrically driven fracturing machine; Y i Assign a value to the total service time of the corresponding preset vulnerable parts for the i-th electrically driven fracturing machine; Z i ω1, ω2, and ω3 are the amplitudes of the usage time of the i-th electrically driven fracturing machine since its most recent start-up; ω1, ω2, and ω3 are preset weights.

[0051] Furthermore, the calculation of the displacement allocation rule for each electric fracturing machine based on the target displacement, displacement increase / decrease step size, and target displacement holding time includes: determining the stepped increase / decrease step size for each electric fracturing machine based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding current electric fracturing machine; generating the expected displacement of each electric fracturing machine at each moment based on the stepped increase / decrease step size and target displacement holding time, which serves as the displacement allocation rule for each electric fracturing machine.

[0052] Specifically, the rule for determining the stepped rise / fall step size of each electric fracturing machine, based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding current electric fracturing machine, is as follows:

[0053] Where, ΔQ i Q represents the stepped lifting / lowering step size of the i-th electrically driven fracturing machine; target,t Let Q be the target displacement of the i-th electrically driven fracturing unit; current,t N represents the current real-time displacement of the i-th electrically driven fracturing unit; i Let be the step number of the i-th electrically driven fracturing machine; the rule for determining the expected displacement of each electrically driven fracturing machine at each moment, based on the step-like rise / fall step size and target displacement holding time, is as follows: Q expected,i(t) =Q current,t +k*ΔQ i

[0054] Among them, Q expected,i(t) Let be the expected displacement of the i-th electrically driven fracturing machine at time t; k is the current ladder number.

[0055] In this embodiment of the invention, the target displacement and real-time displacement of each electrically driven fracturing machine are monitored, and the difference between them is calculated to reflect the deviation between the current displacement and the target displacement. Based on the difference between the target displacement and the real-time displacement, a stepped increase / decrease step size for each electrically driven fracturing machine is determined to achieve gradual adjustment during the displacement regulation process, avoiding abrupt changes and fluctuations. Combining the stepped increase / decrease step size and the target displacement holding time for each electrically driven fracturing machine, the expected displacement of each electrically driven fracturing machine at different times is generated. The generated expected displacement is used as the displacement allocation rule for each electrically driven fracturing machine to guide the displacement adjustment and control of the electrically driven fracturing machine at different stages.

[0056] Based on this invention, by calculating the stepped increase / decrease step size and generating the desired displacement, precise adjustment of the electric fracturing machine's displacement is achieved, ensuring stable fluctuations in displacement around the target value and improving construction efficiency and quality. The application of the stepped increase / decrease step size reduces abrupt changes and fluctuations during displacement adjustment, lowering equipment energy consumption and wear, and extending equipment lifespan. Generating the desired displacement allows the electric fracturing machine to maintain a stable displacement output at different times, ensuring the continuity and stability of the construction process and reducing process problems caused by displacement fluctuations. The established displacement allocation rules enable the electric fracturing machine to automatically adjust its displacement based on real-time conditions, achieving intelligent displacement control, reducing human intervention, and improving operational efficiency.

[0057] Furthermore, the step-by-step control scheme for each electric fracturing machine based on the displacement allocation rule includes: generating a control timing table for each electric fracturing machine based on the expected displacement of each electric fracturing machine at each time moment, as the step-by-step control scheme for each electric fracturing machine.

[0058] In this embodiment of the invention, the expected displacement values ​​of each electrically driven fracturing machine at different times are recorded according to the aforementioned expected displacement generation rules. Based on the expected displacement of each electrically driven fracturing machine at each time, a corresponding control timing table is generated, including the control actions and displacement adjustment strategies that each electrically driven fracturing machine should take in each time period. According to the control timing table corresponding to the expected displacement, a stepped control scheme for each electrically driven fracturing machine is designed to determine how the displacement should be adjusted in different time periods to achieve a stable output of the expected displacement. Control strategies for different situations are formulated, including the adjustment of the lifting and lowering step size, the setting of the displacement holding time, and the handling of abnormal situations, to ensure that the displacement control of the electrically driven fracturing unit can be stable and reliable under various operating conditions.

[0059] Step S30: Execute the stepped control scheme for each electric fracturing machine and monitor the real-time pressure inside the well during the execution process.

[0060] Specifically, pressure sensors are installed at key locations at the wellhead and downhole to monitor pressure changes within the well in real time. A data acquisition system is established to periodically or in real-time acquire displacement data and well pressure data for each electrically driven fracturing machine, ensuring data timeliness and accuracy. Data processing algorithms are used to process the real-time acquired data, including data cleaning, noise reduction, and data alignment, to ensure data accuracy and reliability. A well pressure prediction model is established to predict well pressure change trends over a future period based on historical and real-time monitoring data, providing a reference for control decisions. Based on the control timing table generated by the tiered control scheme, the control system issues corresponding control commands to each electrically driven fracturing machine to adjust displacement and control parameters. Real-time monitoring of well pressure changes is conducted, and the monitoring data is fed back to the control system to achieve real-time adjustment and optimization of the control scheme.

[0061] Based on the present invention, by real-time monitoring of well pressure and execution of a stepped control scheme, it is possible to respond promptly to changes in well pressure, adjust the displacement of the electric fracturing unit, and maintain the well pressure within a safe range. Based on real-time monitoring data and a pressure prediction model, the stepped control scheme is optimized, improving control accuracy and stability while reducing operational risks. The application of the real-time monitoring system reduces the need for human intervention, improves operational efficiency and safety, and reduces the workload of operators. Combining the real-time monitoring system and the stepped control scheme enables intelligent management of the electric fracturing unit, improving operational efficiency and quality.

[0062] Step S40: Determine whether the real-time pressure inside the well is not less than the preset protection pressure, and trigger the corresponding protection rule when it is not less than the preset protection pressure.

[0063] Specifically, the preset protection pressure includes multiple preset protection pressures, each with a different pressure threshold. The protection rules for each preset protection pressure may be the same or different; the protection rules for each preset protection pressure can be any one of maintaining discharge rate, reducing discharge rate, or stopping the pump.

[0064] In this embodiment of the invention, multi-level preset protection pressure thresholds are set for different downhole conditions and operational requirements, enabling judgment and control based on real-time monitored well pressure data. Corresponding protection rules are formulated for each preset protection pressure level, including any one of maintaining discharge rate, reducing discharge rate, and stopping the pump, to address pressure changes under different conditions. Well pressure changes are monitored in real time by pressure sensors, and the monitoring data is transmitted to the control system for real-time processing and analysis. Based on the set multi-level preset protection pressures and protection rules, the control system judges the well pressure status in real time and selects appropriate protection measures, such as adjusting the discharge rate or stopping the pump, as appropriate. A pressure prediction model is established based on historical data and real-time monitoring data to predict pressure change trends over a future period, providing a reference for multi-level protection control. An intelligent scheduling algorithm is used to dynamically adjust the multi-level preset protection pressures, automatically selecting the optimal control strategy based on real-time pressure conditions and protection rules, improving operational efficiency and safety.

[0065] Based on the present invention, by setting multiple preset protection pressures and different protection rules, a multi-layered protection mechanism is achieved, improving the ability to respond to changes in well pressure and reducing operational risks. Utilizing intelligent control algorithms and pressure prediction models, intelligent management of the multiple preset protection pressures is realized, improving control accuracy and stability. Based on real-time monitoring data and set protection rules, the pumping rate is adjusted or the pump is stopped in a timely manner to maintain the well pressure within a safe range, ensuring smooth operation. The application of the intelligent control system reduces the need for human intervention, improves operational efficiency and safety, and reduces the workload of operators.

[0066] Preferably, when the preset protection pressure is not reached, the displacement control of each electric fracturing machine is continuously executed based on the stepped control scheme of each electric fracturing machine; when each electric fracturing machine reaches the corresponding stepped displacement, a timer is set, and when the timer reaches the preset time, the next step control is executed until the target displacement of each electric fracturing machine is reached.

[0067] In one possible implementation, as shown in Figure 2, the electrically driven fracturing unit is equipped with multiple downhole pressure sensors to collect downhole pressure data in real time. Multiple preset protection pressure levels are set, each corresponding to a protection rule (e.g., maintaining flow rate, reducing flow rate, or stopping the pump). Based on the real-time pressure data, the control system dynamically selects appropriate protection measures (such as adjusting the flow rate or stopping the pump) to ensure that the downhole pressure is maintained within a safe range.

[0068] Main steps:

[0069] 1) Monitoring well pressure: The pressure sensor collects the well pressure in real time and transmits the data to the control system for processing.

[0070] 2) Setting multi-level protection pressure thresholds: The system sets multiple preset protection pressures, typically including three or more levels of protection pressure. For example:

[0071] Level 1 protection pressure: set to 80MPa. Exceeding this pressure will trigger "displacement hold".

[0072] Secondary protection pressure: set at 85MPa. Exceeding this pressure will trigger "reduction of discharge".

[0073] Level 3 protection pressure: set to 90MPa. Exceeding this pressure will trigger a "pump stop".

[0074] 3) Real-time pressure status assessment: The control system continuously assesses whether the pressure inside the well exceeds the preset protection pressure threshold. If the pressure exceeds the preset threshold, the system triggers the corresponding protection rules.

[0075] 4) Implement protection measures: Based on real-time pressure and set protection rules, the control system automatically selects the optimal protection measures:

[0076] Discharge maintenance: When the pressure approaches the first-level protection pressure, maintain the current discharge rate to stabilize the pressure inside the well.

[0077] Reduce discharge rate: When the pressure approaches the secondary protection pressure, gradually reduce the discharge rate to reduce the pressure inside the well and ensure that it does not exceed the safe range.

[0078] Pump shutdown: When the pressure exceeds the third-level protection pressure, the pump should be shut down immediately to prevent the pressure inside the well from rising further and to avoid an overpressure accident.

[0079] 5) Intelligent Scheduling and Prediction: Based on historical and real-time monitoring data, a pressure prediction model is established to predict pressure change trends over a certain period. Based on the prediction results, multi-level protection pressures and measures are dynamically adjusted to ensure that the well pressure remains within a safe range.

[0080] 6) Continue to implement stepped control: If the pressure does not reach the preset protection pressure, the system continues to implement displacement control based on the stepped control scheme of each electric fracturing machine. When each step target is reached, the timer is maintained until the next step control target is reached, until the target displacement of all fracturing machines is reached.

[0081] Step S50: Execute the corresponding protection scheme based on the corresponding protection rule until the electric fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

[0082] Specifically, if the protection scheme corresponding to the current protection rule is to maintain the discharge rate, a preset discharge rate maintenance time is determined, and the discharge rate maintenance of each electrically driven fracturing machine is executed based on the preset discharge rate maintenance time; if the protection scheme corresponding to the current protection rule is to reduce the discharge rate, the discharge rate reduction amount, the discharge rate reduction step, and the target discharge rate maintenance time are determined based on the difference between the real-time pressure in the well and the pressure threshold of the corresponding level preset protection pressure, and the control of each electrically driven fracturing machine is executed based on the determined discharge rate reduction amount, discharge rate reduction step, and target discharge rate maintenance time; if the protection scheme corresponding to the current protection rule is to stop the pump, each electrically driven fracturing machine is controlled to stop working.

[0083] 1) Displacement Maintenance Scheme: Based on operational requirements and downhole conditions, a preset displacement maintenance time is set, which is the duration for which the current displacement needs to be maintained when encountering abnormal pressure. When the protection rule is displacement maintenance, the system maintains the current displacement unchanged according to the preset displacement maintenance time setting, ensuring stable well pressure and avoiding the impact of excessively high or low pressure on operations.

[0084] 2) Discharge Reduction Scheme: By calculating the difference between the real-time pressure in the well and the corresponding preset protection pressure threshold, the required discharge reduction amount is determined to restore the pressure to a safe range. Based on pressure changes, a step value for discharge reduction is set, i.e., the amount of discharge change adjusted each time, to smoothly adjust the well pressure. Based on operational needs and pressure recovery speed, the target discharge maintenance time is determined, i.e., the timeframe for reaching the target discharge level. Based on the determined discharge reduction amount, discharge reduction step size, and target discharge maintenance time, the system gradually adjusts the discharge of the electrically driven fracturing machine, allowing the well pressure to gradually recover to a safe range.

[0085] 3) Pump shutdown scheme: When the protection scheme corresponding to the protection rule is pump shutdown, the system immediately controls each electric fracturing machine to stop working in order to avoid the pressure from continuing to rise or other abnormal situations from occurring, and to ensure operational safety.

[0086] Based on the present invention, corresponding protection schemes are executed according to different protection rules to ensure that the well pressure remains within a safe range and to avoid operational risks. Through control schemes such as maintaining discharge rate, reducing discharge rate, and stopping the pump, stable operation is maintained, improving operational efficiency. Intelligent algorithms and automated execution optimize the discharge rate adjustment process, reducing the risk of human error and improving operational safety. The system monitors and responds to pressure changes in real time, adjusting control strategies promptly to ensure smooth operation.

[0087] In this embodiment of the invention, the solution improves the timeliness, safety, and continuity of fracturing unit operation. During laboratory testing, this invention can simultaneously operate up to 16 fracturing units. In field testing, a displacement of 14m³ was set. 3 / min, system step size set to 2m 3With a flow rate of / min and a holding time of 10 seconds, this invention achieves a steady and continuous output of the electric fracturing unit, reducing the damage to fracturing pipelines and reservoirs caused by sudden increases in flow rate. During the trial extrusion phase, it enables personalized, automatic, and precise control under different pressure protection levels, reducing fluid loss and the risk of misoperation under human control. Compared to traditional electric fracturing unit control methods, this invention significantly improves the safety, timeliness, and accuracy of electric fracturing unit control.

[0088] Example 1: The initial displacement of the electric drive unit was increased to 3.5m. 3 Start feeding the ball at 0.5 min, then reduce the distance to 2.0 m as the ball approaches its destination. 3 / min, after the ball reaches its position, the pressure suddenly rises by nearly 10MPa, and then after about 1 minute, the system increases the output displacement to 10.0 cubic meters, 12.0 cubic meters, and 14.0 cubic meters, from 12.0m 3 / min to 14.0m 3 During the / min lifting process, the construction pressure rises to the set first-level overpressure protection level of 80MPa, triggering the discharge "hold" function. When the pressure drops to 79MPa, the program detects that the first-level overpressure protection condition is not met and automatically moves towards 14.0m. 3 The target displacement is increased by 14.0 m³ / min. After the pressure rises to the first-level overpressure protection of 80 MPa, the displacement "holding" function is triggered again. This process is repeated automatically until the displacement automatically increases to 14.0 m³ / min. 3 The system operates at a rate of / min until the operation is completed. During the process of reducing the discharge rate, the operator sets the construction discharge rate to 0, and the software program then completes the gradual and automatic reduction of the discharge rate.

[0089] Example 2: The initial displacement of the electric drive unit was increased to 3.5m. 3 / min ball delivery, decreasing to 2.0m when the ball is close to its destination. 3 After the ball reached its position, the pressure suddenly increased by nearly 14 MPa per minute. Then, after about 40 seconds, the pressure dropped by about 1 MPa. The system then increased the total output displacement of the electric drive unit to 8.0 m³, 10.0 m³, and 12.0 m³. When the construction pressure rose to the set first-level overpressure protection level of 81 MPa, the displacement "hold" function was triggered, and the displacement was maintained at 12.0 m³. Subsequently, the on-site commander set the first-level overpressure protection level to 84 MPa and the design value of the output displacement to 12.5 m³. 3 After a period of time, the construction pressure suddenly increased, triggering the Level 2 overpressure protection at 85 MPa. The electric fracturing unit control system implemented the pre-set Level 2 protection measures: reducing the output displacement by 1 m³ / min. 3 / min, hold for 1 second, then continue monitoring the current construction pressure. If the construction pressure continues to trigger the secondary pressure protection, the output displacement will be further reduced by 1m. 3The pressure was monitored at a constant rate of / min for 1 second, and then the current construction pressure was monitored again. Once the construction pressure entered the safe range, the output displacement of the electric drive unit continued to increase according to the designed total displacement. Since the pressure remained consistently at 82MPa, the on-site commander adjusted the design value of the electric drive unit's output displacement to 12.0m³. 3 / min, and the subsequent construction pressure remained within a safe range. In the later stages of construction, the on-site commander gradually increased the design value of the construction equipment displacement to 13.5m based on the actual construction pressure. 3 The entire process was controlled by the electric-driven fracturing unit using self-cruising control, and the fracturing operation was safely completed.

[0090] Figure 3 is a system structure diagram of an electric fracturing unit control system provided in one embodiment of the present invention. As shown in Figure 3, the present invention provides an electric fracturing unit control system, the system comprising: a data acquisition unit, used to respond to the drive control command of the electric fracturing unit and read the currently set target parameters; a scheme generation unit, used to calculate the displacement allocation rules of each electric fracturing unit based on the target parameters, and generate a stepped control scheme for each electric fracturing unit based on the displacement allocation rules; a monitoring unit, used to execute the stepped control scheme for each electric fracturing unit and monitor the real-time pressure in the well during the execution process; a judgment unit, used to judge whether the real-time pressure in the well is not less than a preset protection pressure, and trigger the corresponding protection rule when it is not less than the preset protection pressure; and an execution unit, used to execute the corresponding protection scheme based on the corresponding protection rule until the electric fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

[0091] The present invention also provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described electric fracturing unit control method.

[0092] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0093] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0094] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A control method for an electrically driven fracturing unit, characterized in that, The method includes: Responding to the drive control command of the electric fracturing unit, read the currently set target parameters; The displacement allocation rules for each electric fracturing machine are calculated based on the target parameters, and a step-by-step control scheme for each electric fracturing machine is generated based on the displacement allocation rules. Implement the stepped control scheme for each electrically driven fracturing machine and monitor the real-time pressure inside the well during the execution process; Determine whether the real-time pressure inside the well is not less than the preset protection pressure, and trigger the corresponding protection rule when it is not less than the preset protection pressure; The corresponding protection scheme is executed based on the corresponding protection rule until the electric fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

2. The method according to claim 1, characterized in that, The target parameters include: Displacement increase / decrease step size, target displacement holding time, and target displacement.

3. The method according to claim 2, characterized in that, The calculation of the displacement allocation rules for each electrically driven fracturing machine based on the target parameters includes: Collect the design displacement threshold of each electric fracturing machine, the total usage time of each electric fracturing machine and each preset vulnerable part, and the usage time of each electric fracturing machine since the most recent start-up; Based on the nine-foot calibration method, values ​​are assigned to the design displacement threshold of each electric fracturing machine, the total usage time of each electric fracturing machine and each preset vulnerable part, and the usage time of each electric fracturing machine since the most recent start-up, to obtain the corresponding assigned index. Based on the preset weights corresponding to each assigned index, a weighted summation operation is performed on the assigned indexes of each electric fracturing machine to obtain the displacement allocation score of each electric fracturing machine. Based on the displacement allocation score and target displacement of each electric fracturing machine, the displacement allocation of each electric fracturing machine is performed to obtain the target displacement of each electric fracturing machine. The displacement allocation rules for each electric fracturing machine are calculated based on its target displacement, displacement increase / decrease step size, and target displacement holding time.

4. The method according to claim 3, characterized in that, The calculation rules for the displacement allocation of each electrically driven fracturing machine are as follows: Among them, Q i Let i be the target displacement of the i-th electrically driven fracturing unit; S i The displacement allocation score for the i-th electrically driven fracturing machine; S j The displacement allocation score for the j-th electrically driven fracturing machine; n represents the number of electrically driven fracturing machines; Q total This is the total target displacement.

5. The method according to claim 4, characterized in that, The allocation rule for the displacement distribution score of the i-th electrically driven fracturing machine is as follows: S i =ω1*X i +ω2*Y i +ω3*Z i Among them, X i Assign a value to the design displacement threshold of the i-th electrically driven fracturing machine; Y i Assign a value to the total service time of the corresponding preset vulnerable parts of the i-th electric fracturing machine; Z i Let be the amplitude of the usage time of the i-th electrically driven fracturing machine since its most recent start-up; ω1, ω2, and ω3 are preset weights.

6. The method according to claim 3, characterized in that, The displacement allocation rules for each electrically driven fracturing machine, based on its target displacement, displacement increase / decrease step size, and target displacement holding time, include: The step size for raising / lowering each electric fracturing machine is determined based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding electric fracturing machine. Based on the stepped rise / fall step size and target displacement holding time of each electric fracturing machine, the expected displacement of each electric fracturing machine at each moment is generated, which serves as the displacement allocation rule for each electric fracturing machine.

7. The method according to claim 6, characterized in that, The rule for determining the step-by-step lifting / lowering step size of each electric fracturing machine, based on the difference between the target displacement of each electric fracturing machine and the real-time displacement of the corresponding current electric fracturing machine, is as follows: Where, ΔQ i The stepped lifting / lowering step size for the i-th electrically driven fracturing machine; Q target,t Let i be the target displacement of the i-th electrically driven fracturing unit; Q current,t This represents the current real-time displacement of the i-th electrically driven fracturing machine; N i Let i be the step number of the i-th electrically driven fracturing machine; The rule for determining the expected displacement of each electrically driven fracturing machine at each moment, based on the stepped rise / fall step size and the target displacement holding time, is as follows: Q expected,i(t) =Q current,t +k*ΔQ i Among them, Q expected,i(t) Let be the expected displacement of the i-th electrically driven fracturing machine at time t; k is the current ladder number.

8. The method according to claim 6, characterized in that, The step-by-step control scheme for each electrically driven fracturing machine, generated based on the displacement allocation rule, includes: Based on the expected displacement of each electric fracturing machine at each time moment, a control timing table for each electric fracturing machine is generated as a step-by-step control scheme for each electric fracturing machine.

9. The method according to claim 1, characterized in that, The method further includes: When the preset protection pressure is not reached, the displacement control of each electric fracturing machine is continuously executed based on the stepped control scheme of each electric fracturing machine. When each electric fracturing machine reaches the corresponding step displacement, a timer is maintained, and when the timer reaches the preset time, the next step control is executed until the target displacement of each electric fracturing machine is reached.

10. The method according to claim 1, characterized in that, The preset protection pressure includes multiple preset protection pressures, and the pressure thresholds of each preset protection pressure are different.

11. The method according to claim 10, characterized in that, The protection rules for each preset protection pressure may be the same or different; The protection rules for each preset protection pressure are any one of the following: maintaining discharge volume, reducing discharge volume, and stopping the pump.

12. The method according to claim 11, characterized in that, The corresponding protection scheme executed based on the corresponding protection rule continues until the electrically driven fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule, including: If the protection scheme corresponding to the current protection rule is displacement maintenance, determine the preset displacement maintenance time, and execute displacement maintenance for each electric fracturing machine based on the preset displacement maintenance time; If the protection scheme corresponding to the current protection rule is to reduce the discharge rate, the discharge rate reduction amount, the discharge rate reduction step size, and the target discharge rate holding time are determined based on the difference between the real-time pressure in the well and the pressure threshold of the corresponding level preset protection pressure. Based on the determined discharge rate reduction amount, discharge rate reduction step size, and target discharge rate holding time, the control of each electric fracturing machine is executed. If the protection scheme corresponding to the current protection rule is to stop the pump, control each electrically driven fracturing machine to stop working.

13. A control system for an electrically driven fracturing unit, characterized in that, The system includes: The data acquisition unit is used to respond to the drive control commands of the electric fracturing unit and read the currently set target parameters; The scheme generation unit is used to calculate the displacement allocation rule of each electric fracturing machine based on the target parameters, and generate a step-by-step control scheme for each electric fracturing machine based on the displacement allocation rule. The monitoring unit is used to execute the stepped control scheme of each electric-driven fracturing machine and monitor the real-time pressure inside the well during the execution process; The judgment unit is used to determine whether the real-time pressure in the well is not less than the preset protection pressure, and to trigger the corresponding protection rule when it is not less than the preset protection pressure. The execution unit is used to execute the corresponding protection scheme based on the corresponding protection rule until the electric fracturing unit reaches the currently set target parameters or the target parameters corresponding to the protection rule.

14. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the electric fracturing unit control method according to any one of claims 1-12.

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