Pressure and flow compensation system and method

Abstract

The embodiment of the invention discloses a pressure and flow compensation system and method. The system comprises a hydraulic control module, an electrical control module and an output pump, wherein the electrical control module is used for adjusting hydraulic oil parameters of the hydraulic control module; the hydraulic control module is used for driving the output pump to work through hydraulic oil and adjusting the output pressure and / or the output flow of the output pump through hydraulic oil parameters. The hydraulic control output pump is adopted to replace traditional motor control, the flow of the output pump is adjusted by adjusting the flow of the hydraulic oil pump, the flow phase modulation is small, the pressure change is large, and therefore pressure and flow stepless rapid adjustment is achieved, and the adjustment range is large.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas drilling engineering, and in particular to a pressure and flow compensation system and method. Background Art

[0002] As my country's oil exploration and development moves toward deeper and more complex areas, the problem of safe drilling in narrow density windows has become increasingly prominent, and has become a technical bottleneck that affects the increase in my country's drilling speed and restricts the progress of oil exploration and development.

[0003] In order to solve the narrow window problem, the existing technology has added a back pressure pump compensation system on the basis of the original drilling technology. Although the compensation for pressure and flow is achieved, due to the use of a traditional motor to control the output pump, the motor operating frequency is fixed, the output pump flow is fixed, and only the pressure can be adjusted. Due to power limitations, the pressure cannot be over-adjusted, which makes the pressure and flow adjustment process complicated, and it is impossible to meet the requirements of high pressure and large flow at the same time. Summary of the invention

[0004] The present application provides a pressure and flow compensation system and method to realize the compensation of wellbore pressure and flow in deep well and ultra-deep well drilling and completion operations.

[0005] According to one aspect of the present application, a pressure and flow compensation system is provided, the system comprising: a hydraulic control module, an electrical control module and an output pump; wherein,

[0006] The electrical control module is used to adjust the hydraulic oil parameters of the hydraulic control module;

[0007] The hydraulic control module is used to drive the output pump to work through hydraulic oil, and to adjust the output pressure and / or output flow of the output pump through hydraulic oil parameters.

[0008] According to another aspect of the present application, a pressure and flow compensation method is provided, the method comprising:

[0009] Acquire the actual output pressure and / or output flow rate of the output fluid of the output pump through the detection device, and determine the error parameter according to the actual output pressure and / or output flow rate and the preset output pressure and / or output flow rate;

[0010] Determining adjustment parameters of the electrical control module according to the error parameters;

[0011] The hydraulic oil parameters of the hydraulic control module are adjusted according to the adjustment parameters by the electrical control module, so as to adjust the output pressure and / or output flow of the output pump by the hydraulic oil parameters.

[0012] The technical solution of the embodiment of the present application adopts a hydraulically controlled output pump instead of traditional motor control, and adjusts the flow of the output pump by adjusting the flow of the hydraulic oil pump. The flow phase adjustment is small and the pressure change is large, thereby realizing stepless and rapid adjustment of pressure and flow and a large adjustment range.

[0013] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 A schematic diagram of the pressure and flow compensation system provided in Example 1 of the present application;

[0016] Figure 2 A schematic diagram of the structure of an electrical control module provided in Embodiment 2 of the present application;

[0017] Figure 3 A schematic diagram of the structure of a hydraulic control module provided in Example 2 of the present application;

[0018] Figure 4 An overall structural diagram of a pressure and flow compensation system provided in Example 2 of the present application;

[0019] Figure 5 A pressure and flow compensation system workflow diagram provided in Example 2 of the present application;

[0020] Figure 6 A flow chart of a pressure and flow compensation method provided in Example 3 of the present application;

[0021] Figure 7 A flow chart of a flow control method provided in Embodiment 4 of the present application;

[0022] Figure 8 A flow chart of a pressure control method provided in Example 5 of the present application;

[0023] Fig. 9 A proportional variable control diagram provided in Example 5 of the present application;

[0024] Fig.10 This is a constant power control diagram provided in Example 5 of the present application. DETAILED DESCRIPTION

[0025] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it can be understood that the exemplary embodiments described herein are only used to explain the present application, rather than to limit the present application. On the contrary, the present application provides these embodiments in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art. In addition, it should be noted that, for ease of description, only parts related to the present application, rather than all structures, are shown in the accompanying drawings.

[0026] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0027] The following is a detailed description of the system and method for item headers provided in the embodiments of the present application through the following embodiments and their optional solutions.

[0028] Embodiment 1

[0029] Figure 1 This is a schematic diagram of a pressure and flow compensation system structure provided in Example 1 of the present application. The embodiment of the present application can be applied to the situation of oil production. Typically, it can be applied to solve the narrow window situation of drilling. Figure 1 As shown, the pressure and flow compensation system provided in the embodiment of the present application may include: an electrical control module 110, a hydraulic control module 120 and an output pump 130. Among them:

[0030] Electrical control module 110: used to adjust the hydraulic oil parameters of the hydraulic control module.

[0031] The hydraulic control module 120 is used to drive the output pump to work through the hydraulic oil, and to adjust the output pressure and / or output flow of the output pump through the hydraulic oil parameters.

[0032] Among them, hydraulic oil refers to the hydraulic medium used in the hydraulic system by utilizing liquid pressure energy, and plays the role of energy transfer, anti-wear, system lubrication, anti-corrosion, anti-rust, cooling, sealing, etc. in the hydraulic system; the hydraulic oil parameters can be hydraulic flow and hydraulic pressure. The output pump can be a pump that can output mud. The output pressure and / or output flow refer to the parameters of the output pump outputting mud. For example, the output pump piston has a diameter of 140mm, a working stroke of 120mm, and L(mud) / L(hydraulic)=1.57. The output mud of a single stroke is L(mud)=π×70 2 ×240×10 -6 =3.69L. When the output flow rate of the output pump L(mud)=600L / min(10L / s), the maximum number of strokes n=600 / 3.69=162.6 times, L(hydraulic pressure)=600 / 1.57=382L / min<L(hydraulic pressure)max. This application does not impose any restrictions on the type and model of the output pump.

[0033] Specifically, according to the control target of the system, the control system transmits control information to the electrical control module, and the electrical control module controls the hydraulic control module to absorb hydraulic oil and inject the hydraulic oil into the output pump to drive the output pump to work. In the embodiment of the present application, the applicable scenario is not limited, and the pressure and flow of the wellbore can be adjusted, and the pressure and flow of other scenarios can also be adjusted.

[0034] The technical solution of the embodiment of the present application adopts a hydraulically controlled output pump instead of traditional motor control, and adjusts the flow of the output pump by adjusting the flow of the hydraulic oil pump. The flow phase adjustment is small and the pressure change is large, thereby realizing stepless and rapid adjustment of pressure and flow and a large adjustment range.

[0035] Embodiment 2

[0036] Figure 2 This is a schematic diagram of the electrical control module structure provided in Example 2 of this application. Figure 2 As shown, the electrical control module specifically includes the following contents:

[0037] The electrical control module 110 includes a master controller 111, a proportional valve controller 112 and a proportional relief valve 113.

[0038] The main controller 111 is used to determine the control signal and send the control signal to the proportional valve controller 112;

[0039] Among them, the master controller 111 refers to a device capable of completing the control of the entire system. The master controller of this embodiment is a programmable logic controller (PLC); the control signal can be a current or voltage signal. The proportional valve refers to a hydraulic valve that converts the input electrical signal into force or displacement in proportion, thereby continuously controlling parameters such as pressure and flow; the proportional valve controller 112 refers to a device capable of controlling the proportional valve, which is mainly composed of a proportional electromagnet and a proportional amplifier; the proportional electromagnet is an electro-mechanical conversion device that mainly converts the current signal output by the proportional control amplifier into force or displacement; the proportional control amplifier is an electronic device used to provide a specific performance current to the proportional electromagnet and perform open-loop or closed-loop regulation of the proportional control system.

[0040] The proportional valve controller 112 controls the valve opening of the proportional relief valve 113 through a control signal to adjust the hydraulic oil parameters of the hydraulic control module 120 after the hydraulic oil passes through the proportional relief valve 113 .

[0041] The proportional relief valve 113 is a device that changes the magnitude of the relief pressure by changing the magnitude of the spring force.

[0042] Exemplarily, the electrical control module controls each output current of the proportional valve controller 112 to correspond to the attraction of the proportional solenoid, each suction force of the proportional solenoid corresponds to an output pressure of a gear pump, each output pressure of the gear pump corresponds to an inclination angle α of a hydraulic piston pump, each inclination angle α of the hydraulic piston pump corresponds to a hydraulic flow q, and each hydraulic flow q corresponds to an output flow Q of an output pump 130, thereby controlling the output flow of the output pump 130 through the output current of the proportional valve controller 112.

[0043] The module adopts PLC control system to realize remote control, data collection and transmission; the system has a high degree of automation, which improves the operation safety factor and control accuracy.

[0044] Figure 3 This is a schematic diagram of the hydraulic control module structure provided in Example 2 of this application. Figure 3 As shown, the hydraulic control module specifically includes the following contents:

[0045] The hydraulic control module 120 includes a hydraulic oil pump 121 and a hydraulic oil tank 122 ; the hydraulic oil pump 121 includes a gear pump 124 and a hydraulic plunger pump 123 ; the gear pump 124 and the hydraulic plunger pump 123 are connected via a proportional relief valve 113 ; the gear pump 124 is used to suck hydraulic oil from the hydraulic oil tank 122 .

[0046] Among them, the hydraulic oil pump 121 is a hydraulic component that provides pressurized liquid for hydraulic transmission; the hydraulic plunger pump 123 relies on the reciprocating motion of the plunger in the cylinder body to change the volume of the sealed working chamber to achieve oil suction and oil pressure. The gear pump 124 is a device that relies on the change and movement of the working volume formed between the pump cylinder and the meshing gear to transport liquid or increase its pressure.

[0047] For example, the hydraulic oil pump 121 is a double pump, the displacement of a single pump is 140ml / r, the displacement of the two oil outlets can reach 280ml / r, the rated speed of the motor is 1480r / min, and the maximum output flow is: L(hydraulic)max=280×1480 / 1000=414.4L / min. This example only exemplifies the hydraulic oil pump, and does not limit the model or type of the hydraulic oil pump.

[0048] The proportional relief valve 113 is used to adjust the hydraulic pressure of the hydraulic oil entering the hydraulic plunger pump 123 after passing through the proportional relief valve 113 ; the inclination angle of the swash plate of the hydraulic plunger pump 123 is adjusted by the hydraulic pressure to adjust the hydraulic flow of the hydraulic oil after passing through the hydraulic plunger pump 123 .

[0049] The swash plate inclination angle is the adjustment angle of the hydraulic piston pump, and the displacement of the pump can be adjusted by adjusting the size of the swash plate inclination angle.

[0050] Optionally, the hydraulic piston pump 123 is connected to the output pump 130; the hydraulic oil acts on the output pump 130 after passing through the hydraulic piston pump 123 to drive the output pump 130 to work and adjust the output pressure and / or output flow of the output pump 130 through the hydraulic flow.

[0051] In addition, the hydraulic control module may further include a throttle valve 140 , which is connected to the outlet of the output pump 130 ; the throttle valve 140 is used to determine the valve opening according to the output flow of the output pump 130 to adjust the output pressure of the output pump 130 .

[0052] Among them, valve opening is the valve opening percentage.

[0053] For example, Figure 4 This is a general structural diagram of a pressure and flow compensation system provided in Example 2 of this application. Figure 4As shown, the hydraulic control module 120 as a whole adopts a proportional variable control mode under constant power mode. The hydraulic oil pump 121 is a combination of a hydraulic piston pump 123 and a gear pump 124, and is driven by an explosion-proof motor. The hydraulic piston pump 123 is used for high-pressure work in the main oil circuit, and the gear pump 124 is used for variable control of the hydraulic piston pump 123. The gear pump 124 sucks low-pressure hydraulic oil through the hydraulic oil tank 122, and injects high-pressure oil into the control port of the hydraulic piston pump 123 through the proportional relief valve 113. The proportional relief valve 113 controls the output oil pressure of the gear pump 124. The maximum current and the minimum current of the input proportional relief valve 113 are divided into n equal parts through the electrical control module 120, and each value will correspond to the percentage of the maximum flow of the hydraulic oil pump 121, so as to realize the stepless adjustment of the output flow Q of the output pump 130 through the electrical control module 120. After the output flow Q is determined, the output pressure P of the output pump 130 is adjusted by adjusting the opening of the throttle valve 140.

[0054] The module performs stepless regulation of pressure and flow by changing the flow of the hydraulic oil pump 121, with a large regulation range, achieving low power output and high pressure, reducing energy consumption; at the same time, it realizes real-time monitoring of data such as pressure, flow, and temperature.

[0055] For example, Figure 4 The system shown in the figure adopts a closed skid-mounted box structure as its overall structure, which is convenient for mobile operation and is rainproof and dustproof outdoors. It has a minimal impact on equipment and personnel in harsh environments.

[0056] In addition, in the embodiment of the present application, an electromagnetic overflow valve 160 may also be included, which is connected between the output pump 130 and the hydraulic oil tank 122 and between the output pump 130 and the hydraulic control module 120; the electromagnetic overflow valve 160 is used to control the hydraulic oil of the hydraulic control module 210 to be output to the output pump 130, or to transfer the hydraulic oil from the output pump 130 to the hydraulic oil tank 122.

[0057] Exemplarily, the function of the electromagnetic overflow valve 160 is to cut off and connect the main oil source of the system. When the electromagnetic overflow valve 160 is powered on, the hydraulic oil pump 121 outputs high-pressure oil into the output pump 130 to start working. When the electromagnetic overflow valve 160 is powered off, the hydraulic oil output by the hydraulic oil pump 121 directly returns to the hydraulic oil tank 122 without generating high pressure. The output pump 130 does not work, and the system is in an idle state. There is a manual knob on the electromagnetic overflow valve 160 for setting the upper limit pressure of the high-pressure oil output by the hydraulic oil pump 121. When the oil pressure reaches the upper limit pressure, the valve core of the electromagnetic overflow valve 160 will open, allowing part of the oil to flow back to the hydraulic oil tank 122, and the oil pressure will no longer continue to rise, which plays a role in safety protection.

[0058] The system also includes: a 75kW motor 170 and a coupling 150 .

[0059] The coupling 150 is mainly used to connect shafts to transmit motion and torque, and can also be used as a safety device.

[0060] Furthermore, a high-pressure flow meter is designed at the outlet of the system, which can accurately measure the amount of drilling fluid pumped into the wellbore. Compared with the flow measured by logging and the outlet flow, it can conveniently measure the displacement change and determine whether there is a small amount of overflow and leakage in the well.

[0061] Furthermore, an accumulator is installed at the output end of the output pump 130 as a pressure buffer device, which can effectively store and stabilize the pulsating pressure, ensure the stable output of pressure, and prevent large fluctuations in the output pressure. In order to meet a wider range of pressure conditions, the pressure output of the piston accumulator is selected, and a high pressure output of 15 to 20 MPa can be achieved under extreme conditions.

[0062] For example, Figure 5 A pressure and flow compensation system workflow diagram provided in Example 2 of this application. Figure 5 As shown, firstly, according to the actual working conditions, the pressure parameters of the hydraulic oil pump and the flow parameters of the output pump are pre-established, and the flow of the output pump is controlled according to the preset pressure parameters and the preset flow parameters. The flow sensor and the pressure sensor detect the current actual flow parameters and the actual pressure parameters in real time, and feed back the actual flow parameters and the actual pressure parameters to the main controller. The main controller adjusts the hydraulic control module according to the error between the actual parameter value and the preset pressure value, thereby realizing the adjustment of the flow and pressure.

[0063] The technical solution of this embodiment can realize stepless regulation of pressure and flow rate by adopting hydraulic control module and electrical control module, and the regulation range is large, realizing wellbore pressure control and flow rate compensation; the system can also realize remote control, data acquisition and transmission, improving the operation safety factor and control accuracy. The equipment can be used in deep well, ultra-deep well and drilling and completion operations to achieve the purpose of wellbore pressure control and flow rate compensation, and provides a technical support for solving the problem of narrow pressure window in deep well and ultra-deep well.

[0064] Embodiment 3

[0065] Figure 6 This is a flow chart of a pressure and flow compensation method provided in Example 3 of the present application. Figure 6 As shown, the method of the embodiment of the present application specifically includes the following steps:

[0066] S210, obtaining actual output fluid parameters of the output fluid of the output pump through a detection device, and determining error parameters according to the actual output fluid parameters and preset output fluid parameters, wherein the real-time output fluid parameters and preset output fluid parameters include actual output pressure and / or actual output flow rate.

[0067] Among them, the detection device refers to a device that can detect the output flow, which can be a flow sensor, flow meter or flow meter, etc.; the error parameter refers to a parameter that can reflect the control effect of the system, usually the relative error is |actual value-preset value| / actual value; the absolute error is actual value-preset value.

[0068] Specifically, the detection device detects the actual output liquid parameters of the output pump, and feeds back the detected actual output liquid parameters to the main controller, and the main controller obtains the error parameters according to the preset output liquid parameters.

[0069] Exemplarily, assuming that the detection device is a flow sensor, the flow sensor detects in real time that the output flow of the output pump is 22L / s, and feeds back the detected information to the main controller. The main controller compares the actual output flow with the preset output flow. The preset output pressure and / or output flow is 30L / s, and is calculated using the error parameter calculation formula, such as relative error = |22-30| / 22≈0.36; absolute error = 22-30 = -8.

[0070] S220: Determine adjustment parameters of the electrical control module according to the error parameters.

[0071] The adjustment parameters refer to the control parameters that can be adjusted automatically or manually according to the error parameters of the system when the system is running.

[0072] Specifically, by judging the size of the error parameter, the adjustment parameters of the electrical control module are adjusted. The adjustment method can be that the staff can manually modify it according to their own work experience and the size of the error parameter; or according to the error parameter, a parameter optimization algorithm can be used to iterate and modify the parameters by themselves until the error parameter meets the control requirements, wherein the parameter optimization control algorithm can be adaptive control, predictive control, fuzzy control, etc. This application does not limit the type of algorithm.

[0073] Exemplarily, a genetic algorithm is used as a parameter optimization algorithm, with error parameters as input and control parameters as output. The genetic algorithm is continuously multiplied and optimized to obtain a control parameter group that meets the control requirements, and the optimized control parameter group is used as the adjustment parameter in subsequent different states.

[0074] S230, adjusting the hydraulic oil parameters of the hydraulic control module according to the adjustment parameters through the electrical control module, so as to adjust the output fluid parameters of the output pump through the hydraulic oil parameters, wherein the output fluid parameters include output pressure and / or output flow.

[0075] Specifically, the electrical control module adjusts the hydraulic oil parameters of the hydraulic control module accordingly according to the adjustment parameters of different control requirements, and indirectly controls the output fluid parameters of the output pump according to the flow change of the outflowing hydraulic oil.

[0076] Optionally, the system also includes a device parking mode function. When the system needs to stop working, it exits the construction state and enters the parking mode. The parking mode function exits all modes, automatically enters the manual mode, the electromagnetic overflow valve is disconnected, and the hydraulic system gradually stops working.

[0077] The technical solution of this embodiment performs stepless flow regulation by changing the flow of the hydraulic system with a large adjustment range, so that the system's pressure, flow, temperature and other data can be monitored in real time; the system is controlled by PLC, which can realize remote control, data collection and transmission; the high degree of automation improves the operation safety factor and control accuracy.

[0078] Embodiment 4

[0079] Figure 7 This is a flow chart of a flow control method provided in the fourth embodiment of the present application. Based on the above embodiment, this embodiment optimizes S220. Figure 7 As shown, the method includes:

[0080] S310, obtaining actual output liquid parameters of the output liquid of the output pump through a detection device, and determining error parameters according to the actual output liquid parameters and preset output liquid parameters. The actual output liquid parameters and the preset output liquid parameters belong to the output flow rate.

[0081] S320. If the error parameter is greater than the first preset threshold value and the preset output liquid parameter is greater than the actual output liquid parameter, the target valve opening of the proportional relief valve is determined according to the sum of the preset output liquid parameter and the error parameter; if the target valve opening is greater than the maximum valve opening, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the target valve opening is used as the adjustment parameter.

[0082] Among them, the first preset threshold is the highest endpoint value for the system to determine whether the current working state needs to be changed. By way of example, the first preset parameter of this embodiment is the endpoint value of the maximum flow error size, which can be set to 20%; the maximum valve opening is the percentage of the maximum valve opening. By way of example, the maximum valve opening is 100%.

[0083] For example, assuming that the first preset threshold is 20%, the preset output liquid parameter is 20L / s, and the actual output liquid parameter is 15L / s, the error parameter is approximately equal to 0.3L / s. In this embodiment, the parameter error refers to the relative error. If the error parameter is greater than the first preset threshold, and the preset output liquid parameter is greater than the actual output liquid parameter, the proportional valve opening is adjusted according to the valve opening corresponding to the flow setting value plus the valve opening corresponding to the flow error, and at the same time, it is determined whether the proportional valve opening required for the current flow exceeds 100%. If it is greater than 100%, the proportional valve opening is adjusted to 100%, and the control signal corresponding to the maximum valve opening of the proportional overflow valve is used as the control parameter of the current system; if it is less than 100%, the calculated valve opening is assigned to the proportional valve, and the control signal corresponding to the target valve opening is used as the adjustment parameter.

[0084] S330. If the error parameter is greater than the first preset threshold value and the preset output liquid parameter is less than the actual output liquid parameter, the target valve opening of the proportional relief valve is determined according to the difference between the preset output liquid parameter and the error parameter; if the target valve opening is less than the minimum valve opening, the control signal corresponding to the minimum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the target valve opening is used as the adjustment parameter.

[0085] The minimum valve opening is a percentage of the minimum valve opening. For example, the minimum valve opening is 0%.

[0086] For example, assuming that the first preset threshold is 20%, the preset output liquid parameter is 15L / s, and the actual output liquid parameter is 20L / s, the error parameter is approximately equal to 0.25L / s. If the error parameter is greater than the first preset threshold, and the preset output liquid parameter is less than the actual output liquid parameter, the proportional valve opening is adjusted according to the valve opening corresponding to the flow setting value minus the valve opening corresponding to the flow error. At the same time, it is determined whether the proportional valve opening required for the current flow is less than 0%. If it is less than 0%, the proportional valve opening is adjusted to 0%, and the control signal corresponding to the maximum valve opening of the proportional overflow valve is used as the control parameter of the current system; if it is greater than 0%, the calculated valve opening is assigned to the proportional valve, and the control signal corresponding to the target valve opening is used as the adjustment parameter.

[0087] S340: If the error parameter is greater than the second preset threshold value and less than or equal to the first preset threshold value, determine a control signal as an adjustment parameter according to the maximum flow of the proportional relief valve and the error parameter.

[0088] The second preset threshold is the lowest endpoint value for the system to judge the current working state. Exemplarily, the second preset threshold in this embodiment is the endpoint value of the lowest flow error size, which can be set to 5%.

[0089] Exemplarily, when the error parameter is between 5% and 20%, the control parameter of the system is determined by the maximum flow of the proportional relief valve and the control signal corresponding to the error parameter.

[0090] S350: If the error parameter is less than or equal to the second preset threshold, the proportional relief valve is not adjusted.

[0091] Exemplarily, when the error parameter is within 5%, the valve position remains unchanged.

[0092] S360. Adjust the hydraulic oil parameters of the hydraulic control module according to the adjustment parameters through the electrical control module, so as to adjust the output fluid parameters of the output pump through the hydraulic oil parameters.

[0093] The technical solution of this embodiment determines whether the current working state needs to increase or decrease the flow rate according to the error relationship between the preset output fluid parameters and the actual output fluid parameters and the relationship between the two, and at the same time controls the flow rate change and determines the output control signal of the current control system by adjusting the size of the valve. This method adjusts the pressure and flow rate steplessly by changing the flow rate of the hydraulic system, has a large adjustment range, realizes the function of low power output and high pressure, improves the working efficiency of the system, and reduces energy consumption and manpower consumption.

[0094] Embodiment 5

[0095] Figure 8 This is a flow chart of a pressure control method provided in Example 5 of the present application. Based on the above examples, this example optimizes S220. Figure 8 As shown, the method includes:

[0096] S410, obtaining actual output fluid parameters of the output fluid of the output pump through a detection device, and determining an error parameter according to the actual output fluid parameters and the preset output fluid parameters. The actual output fluid parameters and the preset output fluid parameters belong to the output pressure.

[0097] S420. If the error parameter is greater than the third preset threshold value and the preset output liquid parameter is greater than the actual output liquid parameter, the maximum output liquid flow rate corresponding to the actual output liquid pressure is determined according to the preset relationship between the output liquid pressure and the output liquid flow rate; if the maximum output liquid flow rate is greater than the output liquid flow rate upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional overflow valve is used as the adjustment parameter; otherwise, the control signal corresponding to the maximum output liquid flow rate is used as the adjustment parameter.

[0098] Among them, the third preset threshold is the highest endpoint value for the system to judge the current working state. Exemplarily, the third preset threshold is the highest endpoint value of the pressure error size, which can be set to 1.5MPa.

[0099] For example, assume that the current pressure parameter is 5MPa, the corresponding power is 20kW, the preset pressure parameter is 3MPa, the third preset threshold is 1.5MPa, and the absolute pressure error is 2MPa. The preset output liquid parameter is 15L / s, and the actual output liquid parameter is 20L / s. The error parameter is greater than the third preset threshold, and the preset output liquid parameter is greater than the actual output liquid parameter. According to the constant power formula P*Q=W, the maximum flow rate under the actual pressure can be obtained, that is, P=W / Q=20 / 5=4, 4 is the maximum flow rate under the current pressure, where P: pressure, unit MPa; Q: flow rate, unit L / s; W: power, unit kW. According to the calculated maximum flow rate, determine whether the flow rate exceeds the maximum flow rate of the output pump. If it exceeds, the valve is fully opened; if it does not exceed, adjust the valve to the valve opening corresponding to the flow rate.

[0100] Furthermore, the preset relationship between the output liquid pressure and the output liquid flow rate includes:

[0101] The product of the output pressure and the output flow is less than or equal to the preset power; and the following conditions are met:

[0102] If the output pressure is constant, and the product of the output pressure and the output flow is less than the preset power, the output flow is positively correlated with the control current; otherwise, the output flow remains unchanged.

[0103] Among them, positive correlation means that when one variable increases, the other variable also increases.

[0104] Specifically, when P is constant and Q is given arbitrarily by the electric control signal: when P×Q≤W, Q is in linear proportional relationship with the electric control signal; when P×Q≈W, Q remains constant and no longer changes with the change of the electric control signal. Among them, the power W can be set to 60kW.

[0105] For example, Fig. 9 This is a proportional variable control diagram provided in Example 5 of the present application. Fig. 9 As shown in the figure, when P is constant and Q is given arbitrarily by the electric control signal: P×Q≤60, when P×Q is below 60, Q is linearly proportional to the electric control signal; when P×Q≈60, Q remains constant and no longer changes with the change of the electric control signal. That is, when P=15MPa, Q can be arbitrarily adjusted within 4L / s; when P=10MPa, Q can be arbitrarily adjusted within 6L / s.

[0106] If the output flow is constant and the product of the output pressure and the output flow is less than the preset power, the output flow remains unchanged; otherwise, the output flow is negatively correlated with the output pressure.

[0107] Among them, negative correlation means that when one variable increases, the other variable decreases accordingly.

[0108] Specifically, when Q is given by an electric control signal and the electric control signal remains constant, and P changes with the load: when P×Q≤W, Q remains unchanged; when P×Q≈W, Q decreases inversely proportionally with the increase of P and no longer matches the electric control signal.

[0109] For example, Fig.10 This is a constant power control diagram provided in Example 6 of the present application. Fig.10 As shown in the figure, when Q is given by the electric control signal and the electric control signal remains constant, and P changes with the load: P×Q≤60, Q remains unchanged when P×Q is below 60; when P×Q≈60, Q decreases inversely with the increase of P and no longer matches the electric control signal. That is, when Q is set to 4L / s, Q remains constant within 15MPa; when P exceeds 15MPa, Q decreases proportionally; when Q is set to 6L / s, Q remains constant within 10MPa, and when P exceeds 10MPa, Q decreases proportionally.

[0110] This step achieves arbitrary adjustment of flow rate within the power range by controlling different parameter variables and adjusting changes in flow rate and pressure, thereby increasing the optional control range of the system and improving the application range of the system, that is, it can be used in various media environments such as drilling fluid, fresh water, and sea water.

[0111] S430. If the error parameter is greater than the fourth preset threshold value and less than or equal to the third preset threshold value, and the preset output pressure and / or output flow rate is greater than the actual output pressure and / or output flow rate, then the maximum output flow rate corresponding to the preset output pressure is determined according to the preset relationship between the output pressure and the output flow rate; if the maximum output flow rate is greater than the output flow upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter, otherwise, the control signal corresponding to the maximum output flow rate is used as the adjustment parameter.

[0112] Among them, the fourth preset threshold is the intermediate endpoint value of the system to judge the current working state. Exemplarily, the fourth preset threshold is the intermediate endpoint value of the pressure error size, which can be set to 1MPa.

[0113] Exemplarily, assuming that the current pressure parameter is 3.5MPa, the corresponding power is 20kW, the preset pressure parameter is 3MPa, the fourth preset threshold is 1MPa, and the absolute pressure error is 0.4MPa. The preset output pressure and / or output flow is 15L / s, and the actual output pressure and / or output flow is 20L / s. The error parameter is greater than the fourth preset threshold and less than the third preset threshold, and the preset output pressure and / or output flow is greater than the actual output pressure and / or output flow. According to the constant power formula P*Q=W, the maximum flow under the actual pressure can be obtained, that is, P=W / Q=20 / 5=4, 4 is the maximum flow under the current pressure. According to the calculated maximum flow, it is determined whether the flow exceeds the maximum flow of the output pump. If it exceeds, the valve is fully opened; if it does not exceed, the valve is adjusted to the valve opening corresponding to the flow.

[0114] S440: If the error parameter is greater than a third preset threshold and the preset output pressure and / or output flow is less than the actual output pressure and / or output flow, a control signal corresponding to when the valve opening of the proportional relief valve is zero is used as an adjustment parameter.

[0115] For example, assuming that the current pressure parameter is 5MPa, the corresponding power is 20kW, the preset pressure parameter is 3MPa, the third preset threshold is 1.5MPa, and the absolute pressure error is 2MPa. The preset output pressure and / or output flow is 15L / s, and the actual output pressure and / or output flow is 10L / s. If the error parameter is greater than the third preset threshold, and the preset output pressure and / or output flow is less than the actual output pressure and / or output flow, the control signal corresponding to the valve opening of the proportional relief valve is zero as the adjustment parameter.

[0116] S450. If the error parameter is greater than the fourth preset threshold value and less than or equal to the third preset threshold value, and the preset output pressure and / or output flow rate is less than the actual output pressure and / or output flow rate, then the maximum output flow rate corresponding to the preset output pressure is determined according to the preset relationship between the output pressure and the output flow rate; if the maximum output flow rate is greater than the output flow upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter, otherwise, the control signal corresponding to the maximum output flow rate is used as the adjustment parameter.

[0117] For example, assume that the current pressure parameter is 3.5MPa, the corresponding power is 20kW, the preset pressure parameter is 3MPa, the fourth preset threshold is 1MPa, and the absolute pressure error is 0.4MPa. The preset output pressure and / or output flow is 15L / s, and the actual output pressure and / or output flow is 10L / s. The error parameter is greater than the fourth preset threshold and less than the third preset threshold, and the preset output pressure and / or output flow is less than the actual output pressure and / or output flow. According to the constant power formula P*Q=W, the maximum flow under the actual pressure can be obtained, that is, P=W / Q=20 / 5=4, 4 is the maximum flow under the current pressure. According to the calculated maximum flow, it is judged whether the flow exceeds the maximum flow of the output pump. If it exceeds, the control signal corresponding to the maximum valve opening of the proportional overflow valve is used as the adjustment parameter; if it does not exceed, the control signal corresponding to the maximum valve opening of the proportional overflow valve is used as the adjustment parameter.

[0118] S460: If the error parameter is greater than the fifth preset threshold value and less than or equal to the fourth preset threshold value, determine a control signal as an adjustment parameter according to the maximum flow of the proportional relief valve and the error parameter.

[0119] Among them, the fifth preset threshold is the lowest endpoint value for the system to judge the current working state. Exemplarily, the fifth preset threshold is the lowest endpoint value of the pressure error size, which can be set to 0.1 MPa.

[0120] Exemplarily, when the error is between 0.1 MPa and 1 MPa, the current control signal is determined according to the maximum flow of the proportional relief valve and the error parameter value, and the signal is used as the adjustment parameter.

[0121] S470: If the error parameter is less than or equal to the fifth preset threshold, the proportional relief valve is not adjusted.

[0122] Exemplarily, when the error is less than 0.1 MPa, the valve position remains unchanged.

[0123] S480. Adjust the hydraulic oil parameters of the hydraulic control module according to the adjustment parameters through the electrical control module, so as to adjust the output pressure and / or output flow of the output pump through the hydraulic oil parameters.

[0124] The technical solution of this embodiment determines whether the valve opening needs to be adjusted in the current working state based on the size relationship between the preset output pressure and / or output flow and the actual output pressure and / or output flow, as well as the error between the preset pressure parameter and the actual pressure parameter. This method performs stepless regulation of pressure and flow by changing the flow of the hydraulic system, has a large regulation range, realizes the function of low power output and high pressure, improves the working efficiency of the system, and reduces energy consumption and manpower consumption.

[0125] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the information expected by the technical solution of this application can be achieved, and this document is not limited here.

[0126] Note that the above are only preferred embodiments of the present application and the technical principles used. Those skilled in the art will understand that the present application is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present application. Therefore, although the present application is described in more detail through the above embodiments, the present application is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present application, and the scope of the present application is determined by the scope of the appended claims.

Claims

1. A pressure and flow compensation system, characterized in that: The system comprises: a hydraulic control module, an electrical control module and an output pump; wherein, The electrical control module is used to adjust the hydraulic oil parameters of the hydraulic control module; The hydraulic control module is used to drive the output pump to work through hydraulic oil, and to adjust the output pressure and / or output flow of the output pump through hydraulic oil parameters.

2. The system according to claim 1, characterized in that The electrical control module includes a master controller, a proportional valve controller and a proportional relief valve; The master controller is used to determine a control signal and send the control signal to a proportional valve controller; The proportional valve controller controls the valve opening of the proportional relief valve through the control signal to adjust the hydraulic oil parameters of the hydraulic oil of the hydraulic control module after passing through the proportional relief valve.

3. The system according to claim 2, characterized in that The hydraulic control module includes a hydraulic oil pump and a hydraulic oil tank; the hydraulic oil pump includes a gear pump and a hydraulic plunger pump; the gear pump and the hydraulic plunger pump are connected via the proportional relief valve; The gear pump is used to suck hydraulic oil from the hydraulic oil tank; The proportional relief valve is used to adjust the hydraulic pressure of the hydraulic oil entering the hydraulic piston pump after passing through the proportional relief valve; the inclination angle of the swash plate of the hydraulic piston pump is adjusted by the hydraulic pressure to adjust the hydraulic flow of the hydraulic oil after passing through the hydraulic piston pump.

4. The system according to claim 3, characterized in that The hydraulic piston pump is connected to the output pump; the hydraulic oil acts on the output pump after passing through the hydraulic piston pump to drive the output pump to work and adjust the output pressure and / or output flow of the output pump through the hydraulic flow.

5. The system according to claim 4, characterized in that The system further comprises a throttle valve connected to the outlet end of the output pump; The throttle valve is used to determine the valve opening according to the output flow of the output pump to adjust the output pressure of the output pump.

6. The system according to claim 1, characterized in that The system further comprises: an electromagnetic overflow valve connected between the output pump and the hydraulic oil tank and between the output pump and the hydraulic control module; The electromagnetic overflow valve is used to control the hydraulic oil of the hydraulic control module to be output to the output pump, or to transfer the hydraulic oil from the output pump to the hydraulic oil tank.

7. A pressure and flow compensation method, characterized in that: The method is performed by the pressure and flow compensation system according to any one of claims 1 to 6, and comprises: Acquire actual output liquid parameters of the output liquid of the output pump through the detection device, and determine the error parameter according to the actual output liquid parameters and the preset output liquid parameters; wherein the real-time output liquid parameters and the preset output liquid parameters include the actual output pressure and / or the actual output flow rate; Determining adjustment parameters of the electrical control module according to the error parameters; The hydraulic oil parameters of the hydraulic control module are adjusted by the electrical control module according to the adjustment parameters, so as to adjust the output fluid parameters of the output pump by the hydraulic oil parameters; wherein the output fluid parameters include output pressure and / or output flow.

8. The method according to claim 7, characterized in that The actual output liquid parameter and the preset output liquid parameter belong to the output flow rate; Determining adjustment parameters of the electrical control module according to the error parameter includes: If the error parameter is greater than a first preset threshold value and the preset output liquid parameter is greater than the actual output liquid parameter, determining a target valve opening of the proportional relief valve according to the sum of the preset output liquid parameter and the error parameter; If the target valve opening is greater than the maximum valve opening, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the target valve opening is used as the adjustment parameter; If the error parameter is greater than a first preset threshold value and the preset output liquid parameter is less than the actual output liquid parameter, determining a target valve opening of the proportional relief valve according to a difference between the preset output liquid parameter and the error parameter; If the target valve opening is less than the minimum valve opening, the control signal corresponding to the minimum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the target valve opening is used as the adjustment parameter; If the error parameter is greater than a second preset threshold value and less than or equal to the first preset threshold value, a control signal is determined as a regulating parameter according to the maximum flow of the proportional relief valve and the error parameter; If the error parameter is less than or equal to the second preset threshold, the proportional relief valve is not adjusted.

9. The method according to claim 7, characterized in that: The actual output liquid parameter and the preset output liquid parameter belong to output pressure; Determining adjustment parameters of the electrical control module according to the error parameter includes: If the error parameter is greater than a third preset threshold value and the preset output liquid parameter is greater than the actual output liquid parameter, determining the maximum output flow rate corresponding to the actual output pressure according to a preset relationship between the output pressure and the output flow rate; If the maximum output flow rate is greater than the output flow rate upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the maximum output flow rate is used as the adjustment parameter; If the error parameter is greater than a fourth preset threshold value and less than or equal to the third preset threshold value, and the preset output liquid parameter is greater than the actual output liquid parameter, then according to a preset relationship between the output pressure and the output flow rate, determining a maximum output flow rate corresponding to the preset output pressure; If the maximum output flow rate is greater than the output flow rate upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the maximum output flow rate is used as the adjustment parameter; If the error parameter is greater than a third preset threshold value and the preset output liquid parameter is less than the actual output liquid parameter, a control signal corresponding to when the valve opening of the proportional relief valve is zero is used as the adjustment parameter; If the error parameter is greater than a fourth preset threshold value and less than or equal to the third preset threshold value, and the preset output liquid parameter is less than the actual output liquid parameter, then determining the maximum output flow rate corresponding to the preset output pressure according to a preset relationship between the output pressure and the output flow rate; If the maximum output flow rate is greater than the output flow rate upper limit of the output pump, the control signal corresponding to the maximum valve opening of the proportional relief valve is used as the adjustment parameter; otherwise, the control signal corresponding to the maximum output flow rate is used as the adjustment parameter; If the error parameter is greater than the fifth preset threshold value and less than or equal to the fourth preset threshold value, determining a control signal as a regulating parameter according to the maximum flow of the proportional relief valve and the error parameter; If the error parameter is less than or equal to the fifth preset threshold, the proportional relief valve is not adjusted.

10. The method according to claim 9, characterized in that The preset relationship between output pressure and output flow includes: The product of the output pressure and the output flow is less than or equal to the preset power; and the following conditions are met: If the output pressure is constant, and the product of the output pressure and the output flow rate is less than the preset power, then the output flow rate is positively correlated with the control signal; Otherwise, the output flow rate remains unchanged; If the output flow is constant, and the product of the output pressure and the output flow is less than the preset power, the output flow remains unchanged; Otherwise, the output flow rate is negatively correlated with the output pressure.

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