Control method for low-pressure device, low-pressure device, displacement control method for fracturing device, and fracturing device

Abstract

A low-pressure device, a control method for a low-pressure device, a fracturing device, and a displacement control method for a fracturing device. The low-pressure device comprises a sand mixing device, a blending device, a sand conveying device, a tank device, and a manifold. The control method for a low-pressure device comprises: receiving fracturing operation design data, wherein the fracturing operation design data comprises key fracturing parameters for fracturing stages in a fracturing process; on the basis of the key fracturing parameters for the fracturing stages, performing linkage control on each part of the low-pressure device; and on the basis of a sand supply rate and / or a fluid supply rate, controlling the low-pressure device to automatically switch the fracturing stages. The control method for a low-pressure device can ensure that each device can operate stably. The fracturing device comprises at least one fracturing pump unit. The displacement control method for a fracturing device comprises: when a deviation value between an actual total displacement of a fracturing pump unit and a preset total displacement is not zero, acquiring from the fracturing pump unit a fracturing pump that has the minimum gear position and the highest health priority, and determining whether an actual single-pump displacement of the fracturing pump has reached a preset single-pump displacement; if the actual single-pump displacement of the fracturing pump has reached the preset single-pump displacement, determining the fracturing pump as a fracturing pump requiring displacement regulation; allocating displacement to the fracturing pump requiring displacement regulation, and on the basis of the allocated displacement, obtaining a target gear position and a target rotation speed of the fracturing pump; and regulating the fracturing pump to the target gear position and the target rotation speed. The displacement control method for a fracturing device can reduce the risk during displacement regulation of a pump unit.

Description

Control methods for low-pressure equipment and control methods for discharge capacity of low-pressure equipment and fracturing equipment.

[0001] Cross-referencing

[0002] This application claims priority to two Chinese patent applications filed on March 25, 2025, entitled "Control Method and Low-Pressure Equipment for Low-Pressure Equipment" and "Control Method and Fracturing Equipment for Fracturing Equipment Discharge," the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application belongs to the technical field of oil and gas, specifically relating to a control method for low-pressure equipment, a control method for the discharge capacity of low-pressure equipment and fracturing equipment, and fracturing equipment. Background Technology

[0004] In the process of increasing production in oil and gas fields, multiple pieces of equipment operate simultaneously. Commanders centrally control equipment in low-pressure areas, including sand mixing, blending, sand conveying, liquid tanks, and manifold valves, while operators manually operate each piece of equipment, coordinating to complete operations in the low-pressure areas. However, as the development scale of shale oil and gas increases, the number of equipment also grows, placing higher demands on the technical skills of command and operation personnel, increasing labor intensity, raising personnel management costs, and increasing the risk factors. Therefore, a highly automated control method is urgently needed. Summary of the Invention

[0005] The purpose of this application is to provide a control method for low-pressure equipment, a control method for the discharge capacity of low-pressure equipment and fracturing equipment, and fracturing equipment.

[0006] This application provides a control method for a low-pressure equipment, wherein the low-pressure equipment includes a sand mixing device, a mixing and blending device, a sand conveying device, a tank device, and a manifold; the control method includes: receiving fracturing construction design data, wherein the fracturing construction design data includes key fracturing parameters for each fracturing stage during the fracturing process; performing coordinated control on the sand mixing device, the mixing and blending device, the sand conveying device, the tank device, and the manifold according to the key fracturing parameters for each fracturing stage; and controlling the low-pressure equipment to automatically switch fracturing stages according to the sand supply and / or liquid supply.

[0007] This application embodiment also provides a low-pressure device using the aforementioned control method for the low-pressure device. The low-pressure device includes: a sand mixing device, a blending device, a sand conveying device, a tank device, a manifold, a control system, and a decision-making system. The tank device includes a liquid tank and an additive tank. The first valves of the sand mixing device, the blending device, the sand conveying device, and the manifold, the second valve of the liquid tank, and the third valve of the additive tank are all electrically connected to the control system. The control system is electrically connected to the decision-making system.

[0008] This application provides a method for controlling the discharge capacity of a fracturing equipment. The fracturing equipment includes at least one fracturing pump group, and each pump group includes multiple fracturing pumps. The control method includes: obtaining the actual total discharge capacity of the fracturing pump group; obtaining a group-controlled discharge capacity deviation value of the fracturing pump group based on the actual total discharge capacity and a preset total discharge capacity; when the group-controlled discharge capacity deviation value is not zero, obtaining the fracturing pump with the lowest gear and the highest health priority in the fracturing pump group, and determining whether the actual discharge capacity of the fracturing pump reaches the preset discharge capacity; if so, identifying this fracturing pump as the fracturing pump whose discharge capacity needs to be adjusted; allocating discharge capacity to the fracturing pump whose discharge capacity needs to be adjusted, and obtaining the target gear and target speed of the fracturing pump based on the allocated discharge capacity; and adjusting the fracturing pump to the target gear and the target speed.

[0009] This application also provides a fracturing device that uses the above-described control method to control the output displacement. Attached Figure Description

[0010] Figure 1 is a flowchart of the control method for low-voltage equipment disclosed in an embodiment of this application;

[0011] Figure 2 is a control logic diagram of the control system disclosed in an embodiment of this application;

[0012] Figure 3 is a first flowchart of the fracturing equipment displacement control method disclosed in an embodiment of this application;

[0013] Figure 4 is a second flowchart of the method for controlling the discharge capacity of fracturing equipment disclosed in the embodiments of this application. Detailed Implementation

[0014] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0015] The terms "first," "second," etc., used in the specification and claims of this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such use of data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class and the number of objects is not limited; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0016] The embodiments of this application will be described in detail below with reference to the accompanying drawings and specific examples and application scenarios.

[0017] Referring to Figures 1 and 2, this application discloses a control method for low-pressure equipment, used to control the low-pressure equipment so that its various working parts can be linked together. The low-pressure equipment may include sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, and manifolds, thereby enabling unified command and coordinated control of the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, and manifolds.

[0018] It should be noted that fracturing operations can be divided into high-pressure and low-pressure zones. Equipment located in the high-pressure zone is high-pressure equipment, such as fracturing trucks, which inject high-pressure fracturing fluid into the formation. Equipment located in the low-pressure zone is low-pressure equipment, such as sand mixing equipment, mixing equipment, and water tanks. These devices provide materials to the equipment in the high-pressure zone. This application's embodiments mainly focus on the coordinated control of equipment located in the low-pressure zone to improve operational stability and efficiency.

[0019] The disclosed control method includes: receiving fracturing construction design data, wherein the fracturing construction design data includes key fracturing parameters for each fracturing stage during the fracturing process; and performing linkage control on the sand mixing equipment, mixing equipment, sand conveying equipment, pipe body equipment and manifold respectively based on the key fracturing parameters for each fracturing stage; and controlling the low-pressure equipment to automatically switch fracturing stages based on the sand supply and / or liquid supply.

[0020] This application embodiment achieves intelligent linkage control through the coordination of structures such as sand mixing equipment, mixing equipment, sand conveying equipment, tank equipment, and manifolds. Based on the key fracturing parameters of each fracturing stage, the sand mixing equipment, mixing equipment, sand conveying equipment, tank, and manifolds are linked for control. Furthermore, automatic switching between stages is achieved based on at least one of the sand supply and liquid supply, thereby effectively alleviating the problem of incoordination between command personnel and operators, improving operational efficiency, reducing the input of manpower and material resources, and also reducing safety risks.

[0021] In this embodiment of the application, the control system of the low-voltage equipment can have two modes: remote control mode and local control mode. Before the operation begins, the operator will select the remote control mode or the local control mode according to the needs of the operation.

[0022] In the local control mode, the control system of the low-voltage equipment controls the equipment information in the low-voltage area itself. During this process, the control system will not receive other instructions (such as instructions issued by the decision system), and will mainly control the operation of the equipment in the low-voltage area through the data stored in the control system.

[0023] For example, before the low-pressure equipment is put into operation, the initial data related to the operation can be pre-stored in the control system. When the low-pressure equipment is in local control mode, the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment and manifold can be controlled separately through the control system to ensure the stable and coordinated operation of each piece of equipment.

[0024] In remote control mode, the control system of low-pressure equipment transfers command authority to other systems (such as decision-making systems), while the control system acts as the command relay part. It can receive commands sent by other systems and control the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment and manifolds respectively according to the received commands, so as to control the stable and coordinated operation of each piece of equipment.

[0025] Optionally, after selecting the remote control mode, the control system of the low-voltage equipment listens for instructions issued by the decision system. After receiving the instructions from the decision system, the control system locks the main control instructions, retains only the basic parameter modification instructions, and modifies the corresponding parameters in the control system according to the basic parameter modification instructions to achieve parameter updates.

[0026] In addition, the control system can unilaterally interrupt control of the decision-making system. After the interruption, the control system will not receive any instructions from the decision-making system.

[0027] Optionally, construction data can be imported into the decision-making system, for example, by manual input or other input methods. The decision-making system analyzes and processes the construction data and generates corresponding control commands. Then, the control commands are sent to the control system of the low-voltage equipment so that the control system can control the equipment in the low-voltage area to operate accordingly based on the control commands of the decision-making system.

[0028] Depending on the different control modes of the low-pressure equipment, the sender of the fracturing construction design data received by the control system varies, specifically:

[0029] Receiving fracturing construction design data includes: when the control system of the low-pressure equipment is in remote control mode, receiving fracturing construction design data issued by the decision system of the low-pressure equipment, and the control system listening to the control commands issued by the decision system, locking at least some of the control commands, and retaining basic parameter modification commands.

[0030] When the control system of the low-pressure equipment is not in remote control mode (i.e., in local control mode), it receives local fracturing construction design data through the control system and does not receive control commands issued by the decision-making system.

[0031] Optionally, after receiving the fracturing construction design data step and before performing the linkage control step, the control method further includes:

[0032] Based on the operating conditions of fracturing operations, information is bound between key fracturing parameters and at least some of the equipment in the low-pressure equipment.

[0033] Based on the above settings, key fracturing parameters can be interconnected with at least some of the equipment that are bound to information. This allows the corresponding equipment to be controlled directly based on the selected key fracturing parameters, without the need for separate control of related equipment. This enables integrated control, simplifies control logic, and reduces control complexity.

[0034] For example, by selecting the first set of key fracturing parameters, the operation of the corresponding equipment can be directly controlled based on the first set of key fracturing parameters.

[0035] Optionally, the key fracturing parameters include at least one of sand concentration, sand type, liquid concentration, liquid type, additive concentration, and additive type.

[0036] Optionally, binding information between key fracturing parameters and at least some of the equipment in the low-pressure equipment may include:

[0037] By binding the sand type with the number of the sand mixing equipment and the number of the sand conveying equipment, the operation of the sand mixing equipment with the corresponding number and the operation of the sand conveying equipment with the corresponding number can be controlled according to the sand type.

[0038] For example, the No. 1 sand mixing unit and the No. 1 sand conveying unit are used to mix and convey the first type of sand, respectively; the No. 2 sand mixing unit and the No. 2 sand conveying unit are used to mix and convey the second type of sand, respectively. When the first type of sand is selected during the fracturing operation, the No. 1 sand mixing unit and the No. 1 sand conveying unit are controlled to achieve the mixing and conveying of the first type of sand; similarly, when the second type of sand is selected during the fracturing operation, the No. 2 sand mixing unit and the No. 2 sand conveying unit are controlled to achieve the mixing and conveying of the second type of sand.

[0039] Optionally, binding information between key fracturing parameters and at least some of the equipment in the low-pressure equipment may also include binding information between the liquid type and the number of the liquid tank included in the tank equipment. Based on this, the operation of the corresponding numbered liquid tank can be controlled according to the liquid type to facilitate the delivery of the corresponding liquid.

[0040] For example, liquid tank number one can contain type one liquid, and liquid tank number two can contain type two liquid. When type one liquid is selected during fracturing operations, liquid tank number one is controlled to output type one liquid; similarly, when type two liquid is selected during fracturing operations, liquid tank number two is controlled to output type two liquid.

[0041] Optionally, binding information between key fracturing parameters and at least some of the equipment in the low-pressure equipment may also include:

[0042] By binding additive type with liquid type, the corresponding liquid type can be adapted according to the additive type.

[0043] For example, when the first type of additive is used in fracturing operations, the corresponding first type of liquid is selected; similarly, when the second type of additive is used in fracturing operations, the corresponding second type of liquid is selected.

[0044] Optionally, binding information between key fracturing parameters and at least some of the equipment in the low-pressure equipment may also include:

[0045] By linking the additive type with the delivery pump number, the operation of the corresponding delivery pump can be controlled based on the additive type.

[0046] For example, pump number one is used to deliver the first type of additive; pump number two is used to deliver the second type of additive. When the first type of additive is selected during the fracturing operation, pump number one is controlled to deliver the first type of additive; similarly, when the second type of additive is selected during the fracturing operation, pump number two is controlled to deliver the second type of additive.

[0047] Optionally, there can be a binding relationship between the sand mixing equipment, sand tanks, and sand types. Taking three screw conveyors and three sand tanks as an example, the three screw conveyors are numbered A, B, and C, and the three sand tanks are numbered Tank 1, Tank 2, and Tank 3. Tank 1 stores 70 / 140 quartz sand and is transported to the mixing tank via screw conveyor A. The binding relationship is 70 / 140 quartz sand - Tank 1 - Screw Conveyor A.

[0048] After binding is completed, in subsequent operations, the sand type in the stage (e.g., 70 / 140 quartz sand, etc.) is used to control the opening of the valve of tank 1 to release sand and to control the auger A to transport sand to the mixing tank.

[0049] Optionally, there can be a binding relationship between the liquid and the manifold valve. For example, the slickwater comes from the water tank and the gum syrup comes from the liquid tank. Opening the water tank valve and closing the liquid tank valve releases the slickwater into the sand mixing equipment; opening the liquid tank valve and closing the water tank valve releases the gum syrup into the sand mixing equipment.

[0050] Optionally, additives are tied to liquids. For example, drag-reducing agents are added to prepare slickwater; gum syrups are added to prepare gum syrups; and the proportion of additives is controlled according to the name of the liquid when switching liquid types.

[0051] Optionally, the additive is paired with the delivery pump. Due to the differences in sand mixing equipment, the delivery pump paired with the same additive may vary. For example, in sand mixing equipment 1, the drag-reducing agent is paired with delivery pump 5, while in sand mixing equipment 2, the drag-reducing agent is paired with delivery pump 4.

[0052] The binding information above is referenced in Tables 1 to 4.

[0053] Table 1. Binding relationship between proppant, screw conveyor, and sand pot.

[0054] Table 2. Binding Relationship between Liquids, Additives, and Transfer Pumps

[0055] Table 3. Binding relationship between liquid and valve

[0056] Table 4. Parameter Settings in Displacement-Following Mode

[0057] In this embodiment of the application, before the operation, the control system of the low-pressure equipment can configure and bind at least some equipment information according to the working conditions of the operation; during the formal operation, if only liquid is pumped in the current stage, the stage can be switched according to the actual accumulated liquid volume value; if sand is pumped in the current stage, the stage can be switched according to the actual accumulated sand volume value, as shown in Table 5.

[0058] Table 5

[0059] Optionally, the low-pressure equipment can be automatically switched between fracturing stages based on at least one of the sand supply rate and the liquid supply rate, including:

[0060] When the fracturing stage is in the fluid pumping stage, if the actual cumulative fluid pumping volume is greater than the preset cumulative fluid pumping volume, the system will automatically switch from the fluid pumping stage to the next fracturing stage; or, when the fracturing stage is in the sand pumping stage, if the actual cumulative sand pumping volume is greater than the preset cumulative sand pumping volume, the system will automatically switch from the sand pumping stage to the next fracturing stage.

[0061] Based on the above steps, the fracturing stage of low-pressure equipment can be automatically switched without human intervention, thereby improving the operating efficiency of low-pressure equipment and eliminating errors caused by human factors, thus reducing the operating error of low-pressure equipment.

[0062] Optionally, referring to Table 5, if there is no sand in stage 1, and the actual cumulative liquid volume is greater than the planned cumulative liquid volume, the system will automatically switch from stage 1 to stage 2; if there is sand in stage 2, and the actual cumulative sand volume is greater than the planned cumulative sand volume, the system will automatically switch from stage 2 to stage 3.

[0063] Optionally, based on the key fracturing parameters of each fracturing stage, the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, and manifold are linked for control, including: controlling the sand concentration or sand ratio of the sand mixing equipment according to the current operating mode of the low-pressure equipment.

[0064] For example, when the low-pressure equipment is currently in the first operating mode, the sand concentration of the sand mixing equipment can be controlled to the first sand concentration or the sand ratio can be controlled to the first sand ratio; when the low-pressure equipment is currently in the second operating mode, the sand concentration of the sand mixing equipment can be controlled to the second sand concentration or the sand ratio can be controlled to the second sand ratio.

[0065] Optionally, the control system of the low-pressure equipment in this application embodiment can support four types of on-site operation modes: single sand mixing operation mode, double sand mixing operation mode, single sand mixing + liquid supply operation mode, and double sand mixing + liquid supply operation mode. The on-site operation mode will also be different depending on the different configurations.

[0066] In the first embodiment, when the low-pressure equipment is currently in single sand mixing operation mode, the sand mixing equipment, sand conveying equipment and liquid tanks included in the tank equipment are controlled in a coordinated manner according to the fracturing construction design data, so that the sand concentration or sand ratio corresponds to the fracturing construction design data.

[0067] In the second embodiment, when the low-pressure equipment is currently in a dual sand mixing operation mode, the sand mixing equipment, sand conveying equipment and liquid tanks included in the tank equipment are controlled in a coordinated manner according to the fracturing construction design data, so that the sand concentration or sand ratio corresponds to the fracturing construction design data.

[0068] In addition, in single-mixing sand operation mode or double-mixing sand operation mode, the operation can be fully automated according to the construction design, and the sand concentration or sand ratio can be kept consistent with the construction design.

[0069] In the third implementation, when the low-pressure equipment is currently in a single sand mixing + fluid supply operation mode, the sand concentration or sand ratio of the sand mixing equipment is increased and the output flow rate of the fracturing fluid is kept constant, or the output flow rate of the fracturing fluid is increased and the sand concentration is kept constant.

[0070] In the fourth embodiment, when the low-pressure equipment is currently in the dual sand mixing + fluid supply operation mode, the sand concentration or sand ratio of the sand mixing equipment is increased and the output flow rate of the fracturing fluid is kept constant, or the output flow rate of the fracturing fluid is increased and the sand concentration is kept constant.

[0071] In addition, in the single sand mixing + liquid supply operation mode or the double sand mixing + liquid supply operation mode, since the liquid supply equipment cannot produce sand, the amount of sand corresponding to the discharge capacity of the liquid supply equipment will be completed by the sand mixing equipment.

[0072] Alternatively, under normal circumstances, the output discharge rate can be controlled by increasing the sand concentration or sand ratio of the sand mixing equipment.

[0073] In some embodiments, the discharge rate may remain constant while the sand concentration is increased.

[0074] For example, in the dual sand mixing + liquid supply operation mode, the discharge capacity of sand mixing equipment 1 is m, the discharge capacity of sand mixing equipment 2 is n, the discharge capacity of liquid supply equipment is p, the working sand concentration is k, and the actual sand concentration set by the sand mixing equipment is j. Based on this, the sand concentration set by the sand mixing equipment is j = (m + n + p) / (m + n) * k.

[0075] In addition, some areas require real-time acquisition of actual sand concentration curves. The sand concentrations acquired by the above methods do not match the actual concentrations. Sand mixing equipment is needed to simulate the uniform distribution of the liquid supply equipment to maintain a constant sand concentration.

[0076] Based on the above, a method that keeps the sand concentration constant while increasing the discharge volume can be adopted.

[0077] For example, in the dual sand mixing + liquid supply operation mode, the discharge capacity of sand mixing equipment 1 is m, the discharge capacity of sand mixing equipment 2 is n, the discharge capacity of liquid supply equipment is p, the working sand concentration is k, and the actual sand concentration set for the sand mixing equipment is j. Based on this, the discharge capacity set for sand mixing equipment 1 is m = m + (p / 2), and the discharge capacity set for sand mixing equipment 2 is n = n + (p / 2).

[0078] Optionally, the additive tank included in the tank equipment is controlled, including: when the fracturing stage switches to the additive supply stage, controlling the additive tank to output a preset amount of additive; or, when the additive type and liquid type are information-bound, when the fracturing stage switches to the liquid supply stage, controlling the additive tank to output a preset amount of additive.

[0079] The additive can operate in two ways: the first is to follow the stage operation, and the second is to follow the liquid discharge.

[0080] When additives are used in a phased operation, the parameters of the delivery pump are set in the construction design, and the amount of additive can be set directly when switching between execution phases.

[0081] When the additive follows the liquid discharge rate, the additive parameters need to be configured in advance, including setting the minimum discharge rate and the discharge rate in per mille.

[0082] In addition, after the additive and liquid are bound together, when switching liquids, the proportion of the additive can be set according to the following formula.

[0083] For example, the minimum allowable discharge rate of the additive is set to n1, the additive percentage coefficient is k1, the actual discharge rate of the sand mixing equipment is set to m1, and the actual discharge rate of the additive is p1.

[0084] When m1 > n1, p1 = m1 * k1 / 1000; when m1 < n1, p1 = 0.

[0085] As shown in Figure 1, the flow of the control method for the low-voltage equipment in this embodiment of the application is as follows:

[0086] First, a construction design is performed to obtain fracturing construction design data. The control mode of the low-pressure equipment is determined, i.e., whether it is in remote control mode or local control mode. When the low-pressure equipment is in remote control mode, the fracturing construction design data can be imported into the decision system. The decision system analyzes and processes the fracturing construction design data to obtain control commands. The decision system sends the control commands to the server. The server determines whether data backup is needed. If backup is needed, the server backs up the data first and then forwards the control commands to the control system. If backup is not needed, the server directly forwards the control commands to the control system. After receiving the control commands, the control system analyzes and processes them, generating multiple control linkage commands, which are then sent to the sand mixing equipment, mixing and blending equipment, sand conveying equipment, tank equipment, and manifolds. This enables coordinated control of the sand mixing equipment, mixing and blending equipment, sand conveying equipment, tank equipment, and manifolds, ensuring stable operation of each piece of equipment and outputting the required fracturing fluid.

[0087] Of course, the control system can also feed back alarm information and parameter information to the decision-making system to form closed-loop control. Additionally, the control system can first feed back alarm information and parameter information to the server, and then the server will confirm whether data backup is needed. If backup is needed, the server will forward the feedback information to the decision-making system after backup; if backup is not needed, the server will directly forward the feedback information to the decision-making system.

[0088] When the low-pressure equipment is in the main control mode, the fracturing construction design data can be directly imported into the control system and pre-stored by the control system. During the fracturing operation, the control system can directly retrieve the pre-stored fracturing construction design data to form multiple control linkage commands, which are then sent to the sand mixing equipment, mixing equipment, sand conveying equipment, tank equipment, and manifold. This enables the linkage control of the sand mixing equipment, mixing equipment, sand conveying equipment, tank equipment, and manifold to ensure that each piece of equipment can operate stably and output the fluid that meets the fracturing requirements.

[0089] As shown in Figure 2, the principle of the remote control mode or the main body control mode in this embodiment of the application is as follows:

[0090] First, confirm whether the low-pressure equipment is in remote control mode. When the low-pressure equipment is in remote control mode, the control system listens for control commands from the decision system. If the listening is successful, the control system will use the listened control commands to perform linkage control on the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, and manifold. When the low-pressure equipment is in local control mode, the control system will directly perform linkage control on the sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, and manifold.

[0091] Based on the control method for the low-pressure equipment described above, this application also discloses a low-pressure equipment that applies the above control method. The disclosed low-pressure equipment includes a sand mixing device, a blending device, a sand conveying device, a tank device, a manifold, a control system, and a decision-making system.

[0092] The tank equipment may include liquid tanks and additive tanks; the sand mixing equipment, mixing equipment, sand conveying equipment and manifold may each be equipped with a first valve, the liquid tank may be equipped with a second valve, and the additive tank may be equipped with a third valve, and the first valve, the second valve and the third valve may all be electrically connected to the control system, and the control system is electrically connected to the decision-making system.

[0093] Based on the above settings, the embodiments of this application can send control commands to the control system through the decision system, and control at least one of the first valve, the second valve, and the third valve to open or close through the control system, thereby correspondingly controlling the sand quantity, liquid flow rate, and additive flow rate to meet the requirements for sand quantity, liquid flow rate, and additive flow rate during fracturing operations.

[0094] In summary, the embodiments of this application can simulate the manual and automated control of sand mixing equipment, mixing equipment, sand conveying equipment, tank equipment, and manifold linkage in stages according to the construction design; in single sand mixing + liquid supply and dual sand mixing + liquid supply modes, the sand concentration and additive concentration are automatically allocated according to the discharge volume according to the needs of the operation; by binding the additive with the liquid type, the flow rate of the additive can be automatically controlled according to the liquid type and discharge volume during construction operations, without the need for manual operation.

[0095] Furthermore, in this embodiment, the control system of the low-pressure equipment integrates the control of all equipment (i.e., low-pressure equipment) in the low-pressure area of ​​the fracturing construction site. During construction operations, the decision-making system sends construction design instructions to the control system of the low-pressure equipment via a forwarding server. After receiving the instructions, the control system will coordinate the control of the sand mixing equipment, mixing equipment, sand conveying equipment, tank equipment, and manifolds, thereby enabling one-click control of all equipment in the low-pressure area. During the operation, the control system of the low-pressure equipment also uploads key parameters, alarm information, and other data of the low-pressure equipment to the decision-making system via a forwarding server, allowing the decision-making system to grasp all information about the operation in the low-pressure area. In addition, the control system of the low-pressure equipment can also support four operating modes: single sand mixing, dual sand mixing, single sand mixing + fluid supply, and dual sand mixing + fluid supply, meeting the operational configuration requirements of most construction sites.

[0096] Referring to Figures 3 and 4, this application discloses a method for controlling the discharge capacity of fracturing equipment. The fracturing equipment includes at least one fracturing pump group, and each fracturing pump group may include multiple fracturing pumps. Optionally, this application divides all the fracturing pumps included in the fracturing equipment into N groups according to the actual field operation mode, with each group including multiple fracturing pumps, where N is greater than or equal to 1.

[0097] The disclosed control method includes: obtaining the actual total discharge of the fracturing pump group, and obtaining the group control discharge deviation value of the fracturing pump group based on the actual total discharge and the preset total discharge.

[0098] When the group control displacement deviation value is not zero, the fracturing pump with the smallest gear and the highest health priority in the fracturing pump group is obtained, and it is determined whether the actual displacement of the fracturing pump with the smallest gear and the highest health priority reaches the preset displacement of the single unit. If it reaches the preset displacement of the single unit, this fracturing pump is identified as the fracturing pump whose displacement needs to be adjusted; the displacement is allocated to the fracturing pump whose displacement needs to be adjusted, and the target gear and target speed of the fracturing pump are obtained according to the allocated displacement; the fracturing pump is adjusted to the target gear and target speed.

[0099] Based on the above steps, the embodiments of this application can automatically control the discharge capacity of multiple fracturing pumps in fracturing equipment, eliminating the need for manual control of the output discharge capacity of each fracturing pump in sequence. This improves control efficiency, reduces the labor intensity of operators, and does not require operators to have high experience and skills, thus realizing automated, intelligent, and unmanned control of fracturing equipment.

[0100] Optionally, obtaining the actual total discharge capacity of the fracturing pump group includes: obtaining the actual discharge capacity of each fracturing pump in the fracturing pump group; and obtaining the actual total discharge capacity of the fracturing pump group based on the actual discharge capacity of each fracturing pump. It should be noted that the actual total discharge capacity of each fracturing pump group is the sum of the actual discharge capacities of all fracturing pumps in that group. The actual discharge capacity of each fracturing pump can be detected by installing a flow meter at the outlet of the fracturing pump.

[0101] For example, the actual displacement of each fracturing pump in the fracturing pump group is Q1, Q2, Q3...Q n The actual total displacement Q of the fracturing pump unit T The formula for calculating Q is: T =Q1 + Q2 + Q3 + ... + Q n

[0102] In addition, the preset total displacement of the fracturing pump unit is set to Q. S The deviation value of the controlled discharge rate of the fracturing pump unit is set as ΔQ. Therefore, the formula for calculating the deviation value ΔQ is: ΔQ = Q S -Q T

[0103] The preset total displacement can be obtained either manually by the operator in the automatic displacement control system of the fracturing equipment, or by receiving parameters from other linked systems. Of course, other methods are also possible, and no specific limitations are made here.

[0104] When the group control displacement deviation value is zero, the displacement allocation is completed, the current cycle ends, and execution starts from the beginning.

[0105] Optionally, before grouping the fracturing pumps, it can be determined whether the status of the fracturing pumps has been confirmed, including: whether the current process is a pumping process, and whether overpressure protection has been triggered; if the status of each fracturing pump has been confirmed, and the current process is a pumping process and overpressure protection has not been triggered, then the grouping requirements are met, and multiple fracturing pumps can be grouped.

[0106] Based on the above steps, it can be ensured that the condition of each fracturing pump meets the requirements before grouping, so as to facilitate the subsequent adjustment of the pump displacement.

[0107] It should be noted here that the above-mentioned execution from scratch can be understood as starting from the step of determining whether the state of the fracturing pump has been determined.

[0108] When the group control displacement deviation is not zero, the control method also includes: determining whether multi-level overpressure protection has been triggered or is being triggered; if multi-level overpressure protection has been triggered or is being triggered, then end the current cycle and start executing from the step of determining whether the status of the fracturing pump has been determined; if multi-level overpressure protection has not been triggered, then obtain the fracturing pump with the smallest gear and the highest health priority in the fracturing pump group.

[0109] Based on this step, it can be seen that when the controlled discharge rate deviation is not zero, it indicates that there may be a problem with the actual total discharge rate of the fracturing pump unit. However, it is also necessary to confirm whether the overpressure protection of the fracturing pump unit has been triggered or is being triggered. If it has been triggered or is being triggered, it indicates that there may be a safety issue with the fracturing pump unit. In this case, to avoid safety problems, the discharge rate of the fracturing pump unit will no longer be adjusted, but the problem of the fracturing pump unit will be checked from the beginning to ensure that the fracturing pump unit can operate normally.

[0110] If the fracturing pump unit does not trigger the multi-stage overpressure protection, it indicates that there is no safety problem and the fracturing pump unit can be operated. At this time, even if the discharge rate fluctuates, it can be adjusted later to bring the discharge rate back to an acceptable range.

[0111] Optionally, the fracturing pump with the smallest gear and the highest health priority in the fracturing pump group can be obtained by: removing fracturing pumps that have reached their maximum displacement in the fracturing pump group; sorting the remaining fracturing pumps in order of increasing gear; sorting them in order of health priority; and selecting the fracturing pump with the smallest gear and the highest health priority.

[0112] It's important to note that the health of a fracturing pump can be comprehensively considered based on factors such as its usage time, maintenance level, and operating status. A fracturing pump that simultaneously meets the criteria of shorter usage time, lower maintenance level, and better operating status has a higher health rating, indicating a lower probability of abnormal pump output during operation. Of course, usage time, maintenance level, and operating status can also be prioritized according to requirements. For example, with usage time as the primary consideration, operating status as the first consideration, and maintenance level as the second, the order of consideration for ranking the fracturing pump's health would be usage time, operating status, and maintenance level. Other orders can also be used to rank the fracturing pump's health; no specific limitations are imposed here.

[0113] Furthermore, fracturing pumps in a fracturing pump group that have reached their maximum displacement cannot have their displacement increased further. Therefore, these pumps, having reached their maximum displacement, are practically impossible to adjust further and should be removed from the group for future displacement adjustments. Conversely, the fracturing pump with the smallest displacement setting (i.e., the smallest displacement) has the greatest displacement adjustment potential. If the controlled displacement deviation is significant, adjusting the displacement of the smallest pump setting allows for the fastest possible adjustment of the actual total displacement of the entire fracturing pump group, quickly bringing it close to or even equal to the preset total displacement.

[0114] Furthermore, after selecting the fracturing pump with the lowest gear and the highest health priority, the control methods also include:

[0115] Determine whether the actual displacement of the fracturing pump with the lowest gear and the highest health priority has reached the preset displacement. If the actual displacement of the fracturing pump has reached the preset displacement, it indicates that the fracturing pump is in the optimal operating state. In this case, the fracturing pump can continue to operate in this state.

[0116] If the actual discharge rate of the fracturing pump with the lowest gear and the highest health priority does not reach the preset discharge rate, it indicates that the fracturing pump can still be adjusted to make its actual discharge rate equal to the preset discharge rate, so that it is in the optimal operating state.

[0117] In addition, if the actual displacement of the fracturing pump with the lowest gear and the highest health priority does not reach the preset displacement, the current gear of the fracturing pump with the lowest gear and the highest health priority can be recorded, and the second-ranked fracturing pump can be reselected based on the current gear and health priority.

[0118] For example, if the fracturing pump with the lowest gear and the highest health priority is currently at gear 2, then when selecting the next fracturing pump, other fracturing pumps in the fracturing pump group can be sorted based on gear 2 and health priority, with the highest-level fracturing pump being the second fracturing pump.

[0119] Determine whether the second-ranked fracturing pump meets the condition that the actual displacement of a single unit reaches the preset displacement of a single unit and does not exceed two gears of the first-ranked fracturing pump.

[0120] If the second-ranked fracturing pump meets the condition that the actual displacement of a single unit reaches the preset displacement of a single unit and does not exceed two gears of the first-ranked fracturing pump, then the second-ranked fracturing pump is determined as the fracturing pump whose displacement needs to be adjusted.

[0121] If the second-ranked fracturing pump does not meet the condition that its actual displacement reaches the preset displacement and does not exceed two gears of the first-ranked fracturing pump, then the remaining fracturing pumps are determined sequentially until the fracturing pump whose displacement needs to be adjusted is selected. If none of the remaining fracturing pumps meet the condition that their actual displacement reaches the preset displacement and does not exceed two gears of the first-ranked fracturing pump, then the current cycle ends, and the process begins again from the step of determining whether the status of the fracturing pump has been determined.

[0122] It's important to note that the pump's gear corresponds to its displacement; a lower gear results in a smaller displacement, and a higher gear in a larger displacement. When increasing the displacement, first eliminate the fracturing pump with the highest gear. Then, select the fracturing pump with the lowest gear (i.e., the smallest displacement) from the remaining pumps and prioritize increasing its displacement. If multiple fracturing pumps have the same gear (same displacement), prioritize increasing the displacement of the pump with the higher health status. Health status can be understood as being determined based on the fracturing pump's condition, such as its total operating time.

[0123] The two gear positions mentioned above can be understood as the maximum difference between the gear positions of every two fracturing pumps in the fracturing pump group being two gear positions. This is because the larger the difference in gear positions, the greater the difference in displacement between the fracturing pumps in the fracturing pump group, which is not conducive to the stable operation of the fracturing pump group.

[0124] Optionally, the displacement of the fracturing pump that requires displacement adjustment is allocated as follows: determining whether the actual displacement of the fracturing pump that requires displacement adjustment will exceed the preset displacement of the single unit after upgrading; if the actual displacement of the single unit does not exceed the preset displacement of the single unit, then the fracturing pump is allocated the maximum displacement of the next gear, and the remaining displacement is subtracted from the allocated displacement; if the actual displacement of the single unit exceeds the preset displacement of the single unit, then only the remaining displacement is allocated.

[0125] For example, when the fracturing pump is in gear one, the displacement is 0.8 cubic meters, and in gear two, the displacement is 1.1 cubic meters. Initially, the fracturing pump is in gear zero, with a target displacement of 1 cubic meter. Determine if the maximum displacement of the next gear (i.e., gear one) is less than 1 cubic meter. If it is, first set the fracturing pump to gear one, allocating 0.8 cubic meters of displacement, leaving 0.2 cubic meters. Moving from gear one to gear two increases the displacement by 0.3 cubic meters, but requires 0.2 cubic meters. Therefore, only allocate 0.2 cubic meters of displacement to the fracturing pump, resulting in a final displacement of 0.8 + 0.2 = 1 cubic meter.

[0126] Furthermore, allocating displacement to fracturing pumps that require flow rate adjustment also includes: calculating the waiting time between each two fracturing pumps increasing their displacement rate in the fracturing pump group based on the allocated displacement value and the displacement increase rate parameter. This step allows for a more stable increase in displacement between the two fracturing pumps in the group. It should be noted that a shorter waiting time indicates a more seamless and smoother process of increasing displacement between the two pumps, thereby reducing the fluctuation of the actual total displacement of the fracturing pump group and making its operation more stable.

[0127] For example, to increase the displacement from 0 cubic meters to 20 cubic meters, you can use a continuous method to increase the displacement, and the speed of increase can be the same or different. You can also use a step-by-step method to increase the displacement, with a waiting period after each increase of a certain number of cubic meters. Therefore, parameters need to be configured in advance when increasing the displacement. These parameters include the speed of displacement increase. For example, if the displacement increases by 0.7 cubic meters when shifting from zero to first gear, and by 0.3 cubic meters when shifting from first to second gear, the waiting time between shifts needs to be determined according to the displacement increase to make the slope relatively straight.

[0128] In this embodiment of the application, after the fracturing pump receives the allocated displacement Q, it can calculate the required gear and speed based on the allocated displacement, that is, the target gear G and the target speed S, and open a separate thread to be responsible for raising the fracturing pump to the target gear and the target speed.

[0129] Taking a plunger pump as an example of a fracturing pump, the calculation formula is: Q = S / R i *p P=π×r 2 ×l×n / R p

[0130] Among them, Ri R represents the reduction ratio of each gear in the transmission, r is the radius of the piston pump, l is the stroke of the piston pump, n is the number of pistons, and R p This is the pump reduction ratio.

[0131] Optionally, the control method further includes: determining whether the set gear is equal to the target gear; if the set gear is less than the target gear, controlling the current fracturing pump to shift up. Additionally, it also determines whether the set speed of the current fracturing pump is equal to the target speed; if it is less than the target speed, controlling the current fracturing pump to increase its throttle to reach the target speed.

[0132] Optionally, after allocating the discharge capacity to the fracturing pump that requires flow rate adjustment, the allocated discharge capacity is counted. If it exceeds the flow rate increase step size, the flow rate increase is held for a period of time in order to achieve a step-by-step increase in discharge capacity.

[0133] Furthermore, the embodiments of this application can also determine the construction pressure in real time. If the pressure exceeds the multi-level overpressure protection value, the discharge rate will be maintained or reduced quickly according to the set parameters to achieve faster and more accurate control of the discharge rate.

[0134] Optionally, the fracturing equipment may include multiple fracturing pump sets, each of which includes multiple fracturing pumps.

[0135] Before obtaining the actual total discharge of the fracturing pump group, the control method also includes: determining the fracturing pump group with the largest discharge difference between the actual total discharge and the preset total discharge among multiple fracturing pump groups, and identifying the fracturing pump group that needs to be upgraded.

[0136] Furthermore, after determining the fracturing pump unit that needs to be upgraded, the control method also includes: determining whether the suction pressure of the fracturing pump unit that needs to be upgraded is greater than the preset suction pressure; if it is not greater than the preset suction pressure, there is a risk of venting, the current cycle ends, and the process starts from the step of determining whether the status of the fracturing pump has been determined; if it is greater than the preset suction pressure, the process of obtaining the actual total discharge of the fracturing pump unit is executed.

[0137] Optionally, before determining which fracturing pump unit needs to be upgraded, the control method may also include:

[0138] Determine whether the status of each fracturing pump has been confirmed, including whether the current process is a pumping process and whether overpressure protection has been triggered; if the status of each fracturing pump has been confirmed, the current process is a pumping process and overpressure protection has not been triggered, then proceed to the step of determining which fracturing pump group needs to be boosted.

[0139] Before implementing the above control methods, parameters can be configured according to the actual situation of the field operation, including: field operation mode settings, fracturing pump group settings, fracturing pump priority settings, maximum displacement settings for each fracturing pump, displacement increase rate control, displacement decrease rate control, minimum suction pressure settings, whether to restore displacement after overpressure settings, maximum displacement settings for each fracturing pump group, and multi-stage overpressure protection settings.

[0140] After setting the above parameters, the fracturing equipment can be set to automatic mode, and the total discharge capacity of each fracturing pump group can be entered to control the fracturing equipment and adjust the discharge capacity through the program.

[0141] Referring to Figure 3, the specific implementation flow of the fracturing equipment displacement control method in this embodiment includes: starting; configuring the configuration parameters of the fracturing equipment according to the actual field operation, and setting the fracturing equipment to automatic mode after the configuration parameters are completed, and inputting the total displacement of each fracturing pump group in its initial state, i.e., the preset total displacement; confirming the status of each fracturing pump to ensure that the status of each fracturing pump meets the operation requirements; after confirming the status of the fracturing pumps, grouping all fracturing pumps to obtain multiple fracturing pump groups, and each fracturing pump group contains at least one fracturing pump; calculating the actual total displacement of each fracturing pump group and comparing it with the preset total displacement to obtain the fracturing pump group with the largest displacement difference, and taking this fracturing pump group as the target fracturing pump group, i.e., the fracturing pump group whose displacement needs to be adjusted; determining the intake of the target fracturing pump group. If the pressure is greater than the preset suction pressure (i.e., the preset minimum suction pressure), and the suction pressure is less than the preset suction pressure, the fracturing pump unit may be at risk of running dry. Return to the fracturing pump status confirmation step. If the suction pressure is greater than the preset suction pressure, the fracturing pump unit meets the discharge control requirements. Confirm whether the actual total discharge of the target fracturing pump unit is equal to the preset total discharge, i.e., whether the group control discharge deviation value of the target fracturing pump unit is zero. If it is zero, the discharge allocation is completed, the current cycle ends, and return to the fracturing pump status confirmation step. If it is not zero, confirm whether multi-stage overpressure protection has been triggered or is being triggered. If multi-stage overpressure protection has been triggered or is being triggered, the current cycle ends, and return to the fracturing pump status confirmation step. If multi-stage overpressure protection has not been triggered, continue to the next step.

[0142] Remove fracturing pumps that have reached their maximum displacement within the target fracturing pump group. Sort the remaining fracturing pumps by their gear position, then sort them by their health priority. Prioritize selecting the fracturing pump with the lowest gear position and highest priority. Determine if the actual displacement of this pump has reached the preset displacement. If it has not reached the preset displacement, record the current gear position of the pump and select the second-ranked fracturing pump. Continue to determine if it meets the condition that its displacement reaches the preset displacement and does not exceed two gear positions of the first-ranked pump. If the condition is met, the second-ranked fracturing pump is identified as the pump whose displacement needs to be adjusted. If the condition is not met, end the current cycle and return to the fracturing pump status confirmation step.

[0143] After identifying the fracturing pump that requires displacement adjustment, it is further determined whether the pump will exceed its displacement limit after being upgraded. That is, whether the actual displacement of a single pump exceeds the preset displacement of a single pump. If it does not exceed the displacement limit, the next maximum displacement level is assigned to the fracturing pump, and the remaining displacement is subtracted from the assigned displacement. If it exceeds the displacement limit, only the remaining displacement is assigned. Based on the value of the assigned displacement and the displacement increase rate parameter, the waiting time required between each two fracturing pumps in the fracturing pump group to increase their displacement is calculated, so as to make the displacement increase more stable.

[0144] After receiving the allocated displacement, the fracturing pump calculates the target gear and target speed required for that displacement.

[0145] Determine if the set gear of the fracturing pump is the target gear. If it is lower than the target gear, control the fracturing pump to upgrade to a higher gear. At the same time, determine if the set speed of the fracturing pump is the target speed. If it is lower than the target speed, control the fracturing pump to increase the throttle to bring the set speed to the target speed.

[0146] Based on the above control method, this application also discloses a fracturing device, which uses the above control method to control the output displacement. The fracturing device may include multiple fracturing pump groups, and each fracturing pump group may include at least one fracturing pump. Optionally, each fracturing pump group includes multiple fracturing pumps.

[0147] In summary, the embodiments of this application can allocate displacement to each fracturing pump according to the total designed displacement. Each fracturing pump can simulate manual displacement increase according to the allocated displacement and execute it automatically. Through multi-stage overpressure protection, the displacement can be quickly reduced to prevent excessive pressure from affecting construction. Based on the amount of displacement increase, the interval time between displacement increases between every two fracturing pumps is calculated to improve the stability of displacement control and alleviate the problem of inconsistent displacement increase rate caused by differences in speed and gear between fracturing pumps.

[0148] A fracturing pump unit typically consists of n fracturing pumps of different types and models, including diesel-driven fracturing pumps, electric-driven fracturing pumps, or other types of fracturing pumps. An automatic circulation / drainage control system for the fracturing pumps is connected to each pump to control the circulation / drainage process.

[0149] The automatic circulation / evacuation control method for fracturing pumps implemented in this application includes the following steps:

[0150] Step 1: Before the fracturing pump circulation / evacuation operation, conduct a safety check of the high-pressure area of ​​the fracturing well site and prevent personnel from entering. Check that the fracturing pump equipment to be circulated / evacuated is in working condition, that the manifold connected to it is properly connected, and that the corresponding valves are open.

[0151] Step 2: Select the fracturing pump to be circulated / emptied in the fracturing pump automatic circulation / evacuation control system.

[0152] Step 3: Check the status and corresponding parameter configuration of all selected fracturing pumps. They must be in the starting state; diesel-driven fracturing pumps and turbo-driven fracturing pumps must be in the idling state; and all auxiliary motors of electric-driven fracturing pumps must be running. Check whether the parameters—circulation displacement value, overpressure protection value, circulation time, minimum supply pressure, discharge pressure fluctuation threshold, and load fluctuation threshold—are configured correctly. Confirm that the associated fluid supply and sand mixing equipment are functioning normally.

[0153] Step 4: Initialize the circulation evacuation status of all fracturing pumps to incomplete, and switch the fracturing pump status to manual.

[0154] Step 5: Method and steps for implementing the fracturing pump circulation and evacuation control process:

[0155] Step 5.1: Determine the system command. If it is a fracturing pump circulation command, start the circulation control process of all fracturing pumps. If it is a fracturing pump venting command, execute the venting control process of all fracturing pumps.

[0156] Step 5.2: If it is a cyclic command, select the nth fracturing pump (n = 1, 2, 3... total number of fracturing pumps), set the cyclic displacement, overpressure protection value, cyclic time, minimum supply pressure, discharge pressure fluctuation threshold, and load fluctuation threshold, set the operation mode to automatic mode, configure the continuous running time of the current fracturing pump equipment to 0, and then proceed to step 5.3. If it is a venting command, select the nth fracturing pump (n = 1, 2, 3... total number of fracturing pumps), set the venting displacement, overpressure protection value, venting time, and venting pressure threshold, set the operation mode to automatic mode, configure the continuous running time of the current fracturing pump equipment to 0, and then proceed to step 5.8.

[0157] Step 5.3: Determine whether the continuous running time of the nth pump exceeds the cycle time value set in step 5.2. If it exceeds, return "Cycle successful" and proceed to step 5.7; if it does not exceed, proceed to step 5.4.

[0158] Step 5.4: Determine whether the pressure value of the fracturing pump exceeds the overpressure protection value set in step 5.2. If it exceeds, return to "Cycle Failure" and continue to cycle the next fracturing pump from step 5.2. If it does not exceed, proceed to step 5.5.

[0159] Step 5.5: Determine whether the suction pressure of the fracturing pump exceeds the minimum supply pressure set in step 5.2, and whether the discharge pressure fluctuation of the fracturing pump is less than the discharge pressure fluctuation threshold set in step 5.2, and whether the load fluctuation is less than the load fluctuation threshold set in step 5.2. If any one of these conditions is not met, return to "loop failure" and continue to cycle the next fracturing pump from step 5.2; if all three conditions are met, proceed to step 5.6.

[0160] Step 5.6: Determine whether the current displacement of the fracturing pump is lower than the circulating displacement value set in step 5.2. If it is lower, increase the speed and shift to a higher gear, and repeat step 5.6. If it is not lower, update the continuous running time of the fracturing pump and proceed to step 5.3.

[0161] Step 5.7: Check if all fracturing pumps have completed their circulation. If not, proceed to step 5.2; if they have, stop the control program.

[0162] Step 5.8: Determine whether the continuous running time of the nth pump exceeds the purging time value set in step 5.2. If it exceeds, return "Purge successful" and proceed to step 5.12; if it does not exceed, proceed to step 5.9.

[0163] Step 5.9: Determine whether the pressure value of the fracturing pump exceeds the overpressure protection value set in step 5.2. If it exceeds, return "Purge Failure" and continue to purge the next fracturing pump from step 5.2. If it does not exceed, proceed to step 5.10.

[0164] Step 5.10: Determine whether the discharge pressure of the fracturing pump is less than the venting pressure threshold set in step 5.2. If it is not satisfied, return "Venting Failure" and continue to vent the next fracturing pump from step 5.2. If all three conditions are met, proceed to step 5.11.

[0165] Step 5.11: Determine whether the current discharge capacity of the fracturing pump is lower than the venting discharge capacity value set in 5.2. If it is lower, increase the speed and shift to a higher gear, and repeat the 5.11 judgment. If it is not lower, update the continuous running time of the current fracturing pump equipment and proceed to 5.8.

[0166] Step 5.12: Check if all fracturing pumps have been emptied. If not, proceed to step 5.2; if so, stop the control program.

[0167] This application provides an automatic circulation / drainage control system for fracturing pumps, comprising a computer-readable storage medium storing a computer program and a processor. The computer program is stored on the storage medium, and when the computer program is read and run by the processor, the automatic circulation / drainage control method for each fracturing pump described above is implemented.

[0168] The automatic circulation / drainage control method and system for fracturing pumps described in this application can be used for automatic circulation / drainage control of various types of fracturing pump equipment, including diesel-driven, electric-driven, and turbine-driven pumps, at oilfield fracturing operation sites.

[0169] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A control method for low-voltage equipment, wherein, The low-pressure equipment comprises sand mixing equipment, blending equipment, sand conveying equipment, tank equipment and a manifold; The control method comprises: receiving fracturing construction design data, wherein the fracturing construction design data comprises key fracturing parameters of each fracturing stage in a fracturing process; performs linkage control on the sand mixing equipment, the blending equipment, the sand conveying equipment, the tank equipment and the manifold respectively according to the key fracturing parameters of each fracturing stage; controlling the low-pressure equipment to automatically switch fracturing stages according to sand supply amount and / or liquid supply amount.

2. The control method according to claim 1, wherein, Receiving the fracturing construction design data comprises: receiving the fracturing construction design data issued by a decision system of the low-pressure equipment when a control system of the low-pressure equipment is in a remote control mode, wherein the control system monitors control instructions issued by the decision system, locks at least part of the control instructions, and retains basic parameter modification instructions; receiving the local fracturing construction design data through the control system when the control system of the low-pressure equipment is not in the remote control mode, and the control system does not receive the control instructions issued by the decision system.

3. The control method according to claim 1, wherein, after the step of receiving the fracturing construction design data and before the step of performing linkage control, the control method further comprises: binding information of the key fracturing parameters and at least part of the equipment in the low-pressure equipment according to working conditions of fracturing operation.

4. The control method according to claim 3, wherein, Binding information of the key fracturing parameters and at least part of the equipment in the low-pressure equipment comprises: binding information of a sand type in the key fracturing parameters with a number of the sand mixing equipment and a number of the sand conveying equipment respectively; and / or binding information of a liquid type in the key fracturing parameters with a number of a liquid tank comprised in the tank equipment; and / or binding information of an additive type in the key fracturing parameters with a liquid type; and / or binding information of an additive type in the key fracturing parameters with a number of a delivery pump.

5. The control method according to claim 1, wherein, Controlling the low-pressure equipment to automatically switch fracturing stages according to the sand supply amount and / or the liquid supply amount comprises: when the fracturing stage is a liquid pumping stage and an actual accumulated liquid pumping amount is greater than a preset accumulated liquid pumping amount, automatically switching from the liquid pumping stage to a next fracturing stage; or, when the fracturing stage is a sand pumping stage and an actual accumulated sand pumping amount is greater than a preset accumulated sand pumping amount, automatically switching from the sand pumping stage to a next fracturing stage.

6. The control method according to claim 1, wherein, Performing linkage control on the sand mixing equipment, the blending equipment, the sand conveying equipment, the tank equipment and the manifold according to the key fracturing parameters of each fracturing stage comprises: controlling sand concentration or sand ratio of the sand mixing equipment according to a current operation mode of the low-pressure equipment.

7. The control method according to claim 6, wherein, when the low-pressure equipment is currently in a single sand mixing operation mode or a double sand mixing operation mode, performing linkage control on the sand mixing equipment, the sand conveying equipment and the liquid tank comprised in the tank equipment respectively according to the fracturing construction design data, so that the sand concentration or the sand ratio corresponds to the fracturing construction design data.

8. The control method according to claim 6, wherein, When the low-pressure equipment is currently in a single sand mixing and fluid supply or a dual sand mixing and fluid supply operation mode, the sand concentration or sand ratio of the sand mixing equipment is increased and the output flow rate of the fracturing fluid is kept constant, or the output flow rate of the fracturing fluid is increased and the sand concentration is kept constant.

9. The control method according to claim 1 or 4, wherein, Controlling the additive tanks included in the tank equipment includes: When the fracturing stage switches to the additive supply stage, the additive tank is controlled to output a preset amount of additive. Alternatively, when the additive type and liquid type are linked, the additive tank can be controlled to output a preset amount of additive when the fracturing stage switches to the liquid supply stage.

10. A low-voltage device, employing the control method according to any one of claims 1 to 9, wherein, The low-pressure equipment includes: sand mixing equipment, blending equipment, sand conveying equipment, tank equipment, manifold, control system and decision system, wherein the tank equipment includes liquid tanks and additive tanks; The sand mixing equipment, the mixing and blending equipment, the sand conveying equipment, the first valve of the manifold, the second valve of the liquid tank, and the third valve of the additive tank are all electrically connected to the control system. The control system is electrically connected to the decision-making system.

11. A method for controlling the discharge capacity of a fracturing equipment, the fracturing equipment comprising at least one fracturing pump group, each of the pump groups comprising multiple fracturing pumps, wherein, The control method includes: Obtain the actual total discharge of the fracturing pump group, and obtain the group control discharge deviation value of the fracturing pump group based on the actual total discharge and the preset total discharge. When the group control displacement deviation value is not zero, the fracturing pump with the smallest gear and the highest health priority in the fracturing pump group is obtained, and it is determined whether the actual displacement of the single unit of the fracturing pump reaches the preset displacement of the single unit. If so, this fracturing pump is determined as the fracturing pump whose displacement needs to be adjusted. Displacement is allocated to the fracturing pump that requires displacement adjustment, and the target gear and target speed of the fracturing pump are obtained based on the allocated displacement. Adjust the fracturing pump to the target gear and the target speed.

12. The control method according to claim 11, wherein, Obtaining the actual total displacement of the fracturing pump unit includes: Obtain the actual displacement of each fracturing pump in the fracturing pump group; The actual total displacement of the fracturing pump group is obtained based on the actual displacement of each individual fracturing pump.

13. The control method according to claim 11, wherein, When the group control displacement deviation value is not zero, the control method further includes: Determine whether multi-level overpressure protection has been triggered or is being triggered; If multi-level overpressure protection has been triggered or is being triggered, then end the current cycle; If the multi-level overpressure protection is not triggered, then the fracturing pump with the lowest gear and the highest health priority in the fracturing pump group is selected.

14. The control method according to claim 11, wherein, The step of obtaining the fracturing pump with the lowest gear and highest health priority in the fracturing pump group includes: Remove the fracturing pumps in the fracturing pump group that have reached their maximum discharge capacity; The remaining fracturing pumps are sorted in order of increasing gear capacity; Sort by health priority; Select the fracturing pump with the lowest gear and the highest health priority.

15. The control method according to claim 14, wherein, After selecting the fracturing pump with the lowest gear and the highest health priority, the control method further includes: Determine whether the actual single-unit displacement of the fracturing pump with the lowest gear and the highest health priority has reached the preset single-unit displacement. If the preset displacement of a single unit is not reached, the current gear of the fracturing pump with the smallest gear and the highest health priority is recorded, and the fracturing pump ranked second is reselected based on the current gear and health priority. Determine whether the second-ranked fracturing pump meets the condition that the actual displacement of the single unit reaches the preset displacement of the single unit and does not exceed two gears of the first-ranked fracturing pump. If the preset displacement of a single unit is reached, the fracturing pump ranked second will be identified as the fracturing pump whose displacement needs to be adjusted. If the preset displacement of a single unit is not reached, the remaining fracturing pumps are determined sequentially until the fracturing pump whose displacement needs to be adjusted is selected. If none of the remaining fracturing pumps meet the condition that the actual displacement of a single unit reaches the preset displacement of a single unit and does not exceed two gears of the fracturing pump ranked first, then the current cycle ends.

16. The control method according to claim 11, wherein, The method of allocating discharge capacity to the fracturing pump that requires flow rate adjustment includes: Determine whether upgrading the fracturing pump that requires displacement adjustment will cause the actual displacement of the single unit to exceed the preset displacement of the single unit. If the actual displacement of a single unit does not exceed the preset displacement of a single unit, the next maximum displacement level is allocated to the fracturing pump, and the remaining displacement is reduced by the allocated displacement. If the actual displacement of a single unit does not exceed the preset displacement of the single unit, then only the remaining displacement will be allocated.

17. The control method according to claim 16, wherein, The method of allocating discharge capacity to the fracturing pump that requires flow rate adjustment also includes: Based on the allocated displacement value and the displacement increase rate parameter, the waiting time required between each two displacement increases of the fracturing pumps in the fracturing pump group is calculated.

18. The control method according to claim 11, wherein, The pressure equipment includes multiple fracturing pump sets; Before obtaining the actual total discharge of the fracturing pump unit, the control method further includes: The fracturing pump group with the largest difference between its actual total discharge and the preset total discharge among the multiple fracturing pump groups is identified as the fracturing pump group that needs to be upgraded.

19. The control method according to claim 18, wherein, After determining which fracturing pump unit needs to be upgraded, the control method further includes: Determine whether the suction pressure of the fracturing pump unit that needs to be increased is greater than the preset suction pressure; If the pressure is not greater than the preset intake pressure, there is a risk of short-circuiting, and this cycle ends. If the pressure is greater than the preset suction pressure, then proceed to the step of obtaining the actual total discharge of the fracturing pump unit.

20. The control method according to claim 18, wherein, Before determining which fracturing pump unit needs to be upgraded, the control method further includes: Determine whether the status of each fracturing pump has been confirmed, including determining whether the current process is a pump injection process and whether overpressure protection has been triggered; If the status of each fracturing pump has been confirmed, the current process is a pumping process, and overpressure protection has not been triggered, then the step of determining which fracturing pump group needs to be boosted is executed.

21. A fracturing device, wherein, The output displacement is controlled by the control method described in any one of claims 11 to 20.

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