An overpressure protection method based on a fracturing pump group

Abstract

The present invention discloses an overpressure protection method based on a fracturing pump group, and relates to the technical field of unconventional oil and gas development. The method comprises the following steps: according to the real-time monitoring pump pressure of the fracturing pump group and the output current of the pump pressure sensor, determine the pump pressure of the fracturing pump with normal pump pressure sensor and the fracturing pump with abnormal pump pressure sensor; obtain the communication status of the fracturing pump group, and calculate the real-time high-pressure main manifold synchronization pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with normal pump pressure sensor and the fracturing pump with abnormal pump pressure sensor; based on the high-pressure main manifold pressure synchronization function of the fracturing pump, perform overpressure protection on the fracturing pump with abnormal pump pressure sensor according to the real-time high-pressure main manifold synchronization pressure. The present invention solves the problem of failure of the overpressure protection function of the fracturing pump with abnormal pump pressure sensor, so that each pump in the fracturing pump group has the overpressure protection function.

Description

Technical Field

[0001] The present invention relates to the technical field of unconventional oil and gas development, and in particular to an overpressure protection method based on a fracturing pump group. Background Art

[0002] In the hydraulic fracturing process of unconventional oil and gas, accurate monitoring of pump pressure plays a vital role in controlling the fracturing construction process. During fracturing operations, 12-24 fracturing pumps are usually deployed for construction operations, and the high-pressure discharge end of the fracturing pump is connected to the high-pressure main manifold through a high-pressure pipeline. Each fracturing pump is equipped with a pump pressure sensor at the high-pressure discharge end of the hydraulic end to monitor the pump pressure. The monitored pump pressure value is compared with its own overpressure protection setting value to trigger the overpressure protection shutdown function.

[0003] During the pipeline pressure test and back pressure stage, a fracturing pump is usually required, which is generally operated at a displacement of no more than 0.1m3 / min. The pump pressure value monitored by the pump triggers the overpressure protection, shuts down the fracturing pump, and controls the pressure of the ground high-pressure manifold to the specified pressure. During the fracturing construction stage, the fracturing equipment sets the overpressure protection value according to the formation conditions. When abnormal conditions occur during construction, if the pump pressure value monitored by each fracturing pump exceeds its own overpressure protection setting value, the overpressure protection is triggered and the automatic shutdown is stopped, so that the command personnel can better control the construction process.

[0004] However, in actual fracturing operations, due to damage, disconnection, short circuit or severe equipment shaking of the pump pressure sensor, usually two or three fracturing pumps cannot accurately monitor the pump pressure. During the pipeline pressure test and back pressure stage, the operator will use a fracturing pump with a normal pump pressure sensor to perform pressure operation. Due to the small volume of the ground pipeline, the pipeline pressure rises quickly. If the pump pressure sensor suddenly fails during this process, there will be a huge safety hazard. During the construction stage, a fracturing pump that cannot monitor the pump pressure value will not be able to perform the overpressure protection shutdown function and can only be shut down manually. If the manual shutdown is not timely, there will be certain construction risks. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the present invention provides an overpressure protection method based on a fracturing pump group, which solves the problem of failure of the overpressure protection function of a fracturing pump with an abnormal pump pressure sensor, and enables each pump in the fracturing pump group to have an overpressure protection function.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0007] An overpressure protection method based on a fracturing pump group comprises the following steps:

[0008] S1. Determine the pump pressure of a fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor according to the real-time monitoring pump pressure of the fracturing pump group and the output current of the pump pressure sensor;

[0009] S2, obtaining the communication status of the fracturing pump group, and calculating the real-time high-pressure main manifold synchronous pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor in step S1;

[0010] S3. Based on the high-pressure main manifold pressure synchronization function of the fracturing pump, overpressure protection is performed on the fracturing pump with an abnormal pump pressure sensor according to the real-time high-pressure main manifold synchronization pressure in step S2.

[0011] Furthermore, step S1 includes the following steps:

[0012] S11, determining whether the real-time monitoring pump pressure of the fracturing pump group exceeds the limit; if so, proceeding to step S12, otherwise determining that the fracturing pump has a normal pump pressure sensor and determining its pump pressure;

[0013] S12, determining whether the output current of the pump pressure sensor 5 seconds before exceeding the limit is within the output current setting range; if so, proceeding to step S13, otherwise determining that the fracturing pump has an abnormal pump pressure sensor;

[0014] S13, determine whether the real-time output current of the pump pressure sensor is greater than or equal to the output current setting threshold; if so, determine that the pump pressure sensor is normal for the fracturing pump, and determine its pump pressure as the maximum range value of the pump pressure sensor; otherwise, determine that the pump pressure sensor is abnormal for the fracturing pump.

[0015] Further, in step S12, the output current setting interval is specifically 4ma-20ma.

[0016] Further, in step S2, the communication status of the fracturing pump group is specifically the communication status between the fracturing pump PLC and the centralized control PLC in the fracturing pump group.

[0017] Further, in step S2, according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor in step S1, the real-time high-pressure main manifold synchronous pressure is calculated, including the following steps:

[0018] A1. Correct the normal fracturing pump pressure of the pump pressure sensor in step S1 by using the fracturing pump surge threshold and arithmetic average filtering method to obtain the normal fracturing pump correction pump pressure of the pump pressure sensor;

[0019] A2. According to the communication status of the fracturing pump group, the fracturing pump with an abnormal pump pressure sensor in step S1 and the fracturing pump with a normal pump pressure sensor in step A1, the pump pressure is corrected, and the real-time high-pressure main manifold synchronous pressure is calculated.

[0020] Furthermore, step A1 includes the following steps:

[0021] A11, determining whether the normal pump stroke of the pressure sensor is less than the pump stroke threshold of the fracturing pump; if so, no correction is made to the pump pressure, otherwise, proceeding to step A12;

[0022] A12. Determine a calibration cycle, obtain a set number of pump pressure data within the calibration cycle, calculate them using an arithmetic mean filter method, obtain the average pump pressure within the calibration cycle, and determine the average pump pressure within the calibration cycle as the calibration pump pressure of the fracturing pump with a normal pump pressure sensor.

[0023] Further, in step A11, the pump stroke threshold of the fracturing pump is 60 strokes.

[0024] Further, in step A12, the correction period is the time of one stroke.

[0025] Further, in step A2, according to the communication status of the fracturing pump group, the fracturing pump with an abnormal pump pressure sensor in step S1 and the fracturing pump with a normal pump pressure sensor in step A1, the real-time high-pressure main manifold synchronous pressure is calculated, which is expressed as:

[0026]

[0027] Wherein: PipePress is the real-time synchronous pressure of the high-pressure main manifold, i is the fracturing pump number in the fracturing pump group, n is the number of fracturing pumps in the fracturing pump group, Press[i] is the calibrated pump pressure of the i-th fracturing pump in the fracturing pump group, TX[i] is the communication status value of the i-th fracturing pump in the fracturing pump group, Count_Press[i] is the pump pressure sensor status value of the i-th fracturing pump in the fracturing pump group, and N is the number of fracturing pumps in the fracturing pump group with normal pump pressure sensors.

[0028] The present invention has the following beneficial effects:

[0029] (1) The present invention determines the pump pressure of a fracturing pump with a normal pump pressure sensor and the pump pressure sensor of a fracturing pump with an abnormal pump pressure sensor according to the real-time monitoring pump pressure of the fracturing pump group and the output current of the pump pressure sensor, then obtains the communication status of the fracturing pump group, calculates the real-time high-pressure main manifold synchronization pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the pump pressure sensor of the fracturing pump with an abnormal pump pressure sensor, and finally, based on the high-pressure main manifold pressure synchronization function of the fracturing pump, performs overpressure protection on the fracturing pump with an abnormal pump pressure sensor according to the real-time high-pressure main manifold synchronization pressure, thereby solving the problem of failure of the overpressure protection function of the fracturing pump with an abnormal pump pressure sensor, and enabling each pump in the fracturing pump group to have an overpressure protection function;

[0030] (2) The present invention uses the fracturing pump pump stroke threshold and arithmetic average filtering method to correct the normal fracturing pump pump pressure of the pump pressure sensor, obtains the normal fracturing pump correction pump pressure of the pump pressure sensor, reduces the pressure fluctuation problem caused by the high pump stroke operation of the fracturing pump, and provides a stable and high real-time pump pressure value for the fracturing pump;

[0031] (3) The present invention uses each fracturing pump PLC to determine in real time whether the data of its own pump pressure sensor is abnormal, and sends the result to the centralized control PLC. The centralized control PLC calculates the real-time high-pressure main manifold synchronization pressure based on the normal pump pressure data. In this process, the communication status of the fracturing pump group is taken into account, that is, the communication status between the fracturing pump PLC in the fracturing pump group and the centralized control PLC, which can provide a more accurate high-pressure main manifold synchronization pressure for the fracturing pump with an abnormal pump pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic flow chart of an overpressure protection method based on a fracturing pump group;

[0033] Figure 2 It is a data interaction schematic diagram of the present invention. DETAILED DESCRIPTION

[0034] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0035] like Figure 1 As shown, an overpressure protection method based on a fracturing pump group includes steps S1-S3, which are specifically as follows:

[0036] S1. According to the real-time monitoring pump pressure of the fracturing pump group and the output current of the pump pressure sensor, the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor are determined.

[0037] In an optional embodiment of the present invention, the present invention utilizes a fracturing pump PLC to connect with a pump pressure sensor of the fracturing pump, monitors the pump pressure of the fracturing pump in real time, and collects the output current of the pump pressure sensor, and then determines the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor.

[0038] like Figure 2 As shown, the present invention utilizes the fracturing pump PLC to determine the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor, and then transmits the pump pressure data (pump pressure) and the pump pressure sensor status value (whether the signal is statistically calculated) to the centralized control PLC.

[0039] Step S1 includes the following steps:

[0040] S11, determine whether the real-time monitored pump pressure of the fracturing pump group exceeds the limit; if so, proceed to step S12, otherwise determine that the fracturing pump has a normal pump pressure sensor and determine its pump pressure.

[0041] S12, determining whether the output current of the pump pressure sensor 5 seconds before exceeding the limit is within the output current setting range; if so, proceeding to step S13, otherwise, determining that the fracturing pump has an abnormal pump pressure sensor.

[0042] The output current setting interval is specifically 4ma-20ma. During normal detection, the pump pressure rises in a gradual process, and when the sensor is abnormal, the current value will jump. The range of the pump pressure sensor used in the present invention is 4ma-20ma. The present invention determines whether it is within the normal range by monitoring the output current of the pump pressure sensor 5 seconds before the limit is exceeded; if so, it can be clearly determined that the limit is exceeded due to the pressure of the pipeline itself exceeding the detection range, and then enters step S13; otherwise, it can be clearly determined that the limit is not caused by the pressure of the pipeline itself exceeding the detection range, so it is determined to be a fracturing pump with an abnormal pump pressure sensor.

[0043] S13, determine whether the real-time output current of the pump pressure sensor is greater than or equal to the output current setting threshold; if so, determine that the pump pressure sensor is normal for the fracturing pump, and determine its pump pressure as the maximum range value of the pump pressure sensor; otherwise, determine that the pump pressure sensor is abnormal for the fracturing pump.

[0044] S2. Obtain the communication status of the fracturing pump group, and calculate the real-time high-pressure main manifold synchronous pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor in step S1.

[0045] In an optional embodiment of the present invention, the communication status of the fracturing pump group is specifically the communication status between the fracturing pump PLC and the centralized control PLC in the fracturing pump group.

[0046] The present invention calculates the real-time high-pressure main manifold synchronous pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor in step S1, including the following steps:

[0047] A1. Correct the normal fracturing pump pressure of the pump pressure sensor in step S1 by using the fracturing pump surge threshold and arithmetic mean filtering method to obtain the normal fracturing pump correction pump pressure of the pump pressure sensor.

[0048] Step A1 includes the following steps:

[0049] A11. Determine whether the normal pump stroke of the pump pressure sensor is less than the pump stroke threshold of the fracturing pump; if so, do not calibrate the pump pressure, otherwise proceed to step A12.

[0050] The pump stroke threshold of the fracturing pump is 60 strokes. When the pump stroke exceeds 60 strokes, the relative speed of the pump is high, the pressure fluctuation caused by the equipment jitter and the flow of liquid in the discharge pipeline increases, and the pump pressure detection at the discharge end of the pump hydraulic end is disturbed. Therefore, the present invention sets the pump stroke threshold of the fracturing pump to 60 strokes.

[0051] A12. Determine a calibration cycle, obtain a set number of pump pressure data within the calibration cycle, calculate them using an arithmetic mean filter method, obtain the average pump pressure within the calibration cycle, and determine the average pump pressure within the calibration cycle as the calibration pump pressure of the fracturing pump with a normal pump pressure sensor.

[0052] The calibration cycle is the time of one stroke. One stroke of the fracturing pump means that the five plungers of the fracturing pump just reciprocate once. The present invention sets the calibration cycle to the time of one stroke, which can better calculate the real pressure of the main line.

[0053] The present invention obtains 10 pump pressure data within the calibration period.

[0054] A2. According to the communication status of the fracturing pump group, the fracturing pump with abnormal pump pressure sensor in step S1 and the fracturing pump with normal pump pressure sensor in step A1, the pump pressure is corrected, and the real-time high-pressure main manifold synchronous pressure is calculated, which is expressed as:

[0055]

[0056] Where: PipePress is the real-time synchronous pressure of the high-pressure main manifold, i is the number of the fracturing pump in the fracturing pump group, n is the number of fracturing pumps in the fracturing pump group, Press[i] is the corrected pump pressure of the i-th fracturing pump in the fracturing pump group, TX[i] is the communication status value of the i-th fracturing pump in the fracturing pump group, TX[i]=1 means that the communication between the i-th fracturing pump PLC and the centralized control PLC in the fracturing pump group is normal, TX[i]=0 means that the i-th fracturing pump in the fracturing pump group is normal. The communication between the fracturing pump PLC and the centralized control PLC is abnormal. Count_Press[i] is the status value of the pump pressure sensor of the i-th fracturing pump in the fracturing pump group. Count_Press[i]=1 indicates that the i-th fracturing pump in the fracturing pump group is a fracturing pump with a normal pump pressure sensor. Count_Press[i]=0 indicates that the i-th fracturing pump in the fracturing pump group is a fracturing pump with an abnormal pump pressure sensor. N is the number of fracturing pumps with normal pump pressure sensors in the fracturing pump group.

[0057] like Figure 2As shown, the present invention uses the centralized control PLC to calculate the real-time high-pressure main manifold synchronous pressure, and sends the calculated high-pressure main manifold synchronous pressure to the fracturing pump PLC.

[0058] S3. Based on the high-pressure main manifold pressure synchronization function of the fracturing pump, overpressure protection is performed on the fracturing pump with an abnormal pump pressure sensor according to the real-time high-pressure main manifold synchronization pressure in step S2.

[0059] In an optional embodiment of the present invention, the present invention uses the fracturing pump PLC to receive the high-pressure main manifold synchronization pressure sent by the centralized control PLC. The fracturing pump has a high-pressure main manifold pressure synchronization function of the fracturing pump, and the present invention sets this function to an on state at the beginning. After the fracturing pump detects an abnormality in the pump pressure sensor, that is, the fracturing pump with an abnormal pump pressure sensor, it can automatically switch to using the high-pressure main manifold synchronization pressure for overpressure protection.

[0060] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0061] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0062] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0063] The present invention uses specific embodiments to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

[0064] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An overpressure protection method based on a fracturing pump group, characterized in that: The following steps are involved: S1. Determine the pump pressure of a fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor according to the real-time monitoring pump pressure of the fracturing pump group and the output current of the pump pressure sensor; Step S1 includes the following steps: S11, determining whether the real-time monitoring pump pressure of the fracturing pump group exceeds the limit; if so, proceeding to step S12, otherwise determining that the fracturing pump has a normal pump pressure sensor and determining its pump pressure; S12, determining whether the output current of the pump pressure sensor 5 seconds before exceeding the limit is within the output current setting range; if so, proceeding to step S13, otherwise determining that the fracturing pump has an abnormal pump pressure sensor; S13, determining whether the real-time output current of the pump pressure sensor is greater than or equal to the output current setting threshold; if so, determining that the pump pressure sensor is normal and the pump pressure is determined as the maximum range value of the pump pressure sensor; otherwise, determining that the pump pressure sensor is abnormal; S2, obtaining the communication status of the fracturing pump group, and calculating the real-time high-pressure main manifold synchronous pressure according to the communication status of the fracturing pump group and the pump pressure of the fracturing pump with a normal pump pressure sensor and the fracturing pump with an abnormal pump pressure sensor in step S1, including the following steps: A1. Correct the normal fracturing pump pressure of the pump pressure sensor in step S1 by using the fracturing pump surge threshold and arithmetic average filtering method to obtain the normal fracturing pump correction pump pressure of the pump pressure sensor; Step A1 includes the following steps: A11, determining whether the normal pump stroke of the pressure sensor is less than the pump stroke threshold of the fracturing pump; if so, no correction is made to the pump pressure, otherwise, proceeding to step A12; A12, determining a calibration period, taking a set number of pump pressure data within the calibration period, and calculating them using an arithmetic average filtering method to obtain a mean pump pressure within the calibration period, and determining the mean pump pressure within the calibration period as the calibration pump pressure of the fracturing pump with a normal pump pressure sensor; A2. According to the communication status of the fracturing pump group, the fracturing pump with abnormal pump pressure sensor in step S1 and the fracturing pump with normal pump pressure sensor in step A1, the pump pressure is corrected, and the real-time high-pressure main manifold synchronous pressure is calculated, which is expressed as: Where: PipePress is the real-time synchronous pressure of the high-pressure main manifold, i is the number of the fracturing pump in the fracturing pump group, n is the number of fracturing pumps in the fracturing pump group, Press[i] is the calibrated pump pressure of the i-th fracturing pump in the fracturing pump group, TX[i] is the communication status value of the i-th fracturing pump in the fracturing pump group, Count_Press[i] is the pump pressure sensor status value of the i-th fracturing pump in the fracturing pump group, and N is the number of fracturing pumps with normal pump pressure sensors in the fracturing pump group; S3. Based on the high-pressure main manifold pressure synchronization function of the fracturing pump, overpressure protection is performed on the fracturing pump with an abnormal pump pressure sensor according to the real-time high-pressure main manifold synchronization pressure in step S2.

2. The overpressure protection method based on the fracturing pump group according to claim 1 is characterized in that: In step S12, the output current setting interval is specifically 4ma-20ma.

3. The overpressure protection method based on the fracturing pump group according to claim 1 is characterized in that: In step S2, the communication status of the fracturing pump group is specifically the communication status between the fracturing pump PLC and the centralized control PLC in the fracturing pump group.

4. The overpressure protection method based on the fracturing pump group according to claim 1 is characterized in that: In step A11, the pump stroke threshold of the fracturing pump is 60 strokes.

5. The overpressure protection method based on the fracturing pump group according to claim 1 is characterized in that: In step A12, the correction period is the time of one stroke.

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