CN118128489A - Fracturing fluid flowback control method and device for coalbed methane well - Google Patents

Abstract

The invention provides a fracturing fluid flowback control method and device for a coal-bed gas well, and belongs to the technical field of production control of the coal-bed gas well. The fracturing fluid flowback control method of the coal-bed gas well comprises the following steps: acquiring wellhead pressure in real time in the process of flowback of fracturing fluid of a coal-bed gas well, and intensively determining a current fracturing fluid flowback control stage in a preset fracturing fluid flowback control stage based on the wellhead pressure; the preset fracturing fluid flowback control stage set comprises a plurality of fracturing fluid flowback control stages and a plurality of control strategies respectively corresponding to the plurality of fracturing fluid flowback control stages, and the rate of fracturing fluid flowback is controlled based on the control strategy corresponding to the current fracturing fluid flowback control stage. The time node of the fracturing fluid flowback can be defined, the on-site production flow and measures can be systematically arranged, and the effect of dredging the stratum seepage channel can be achieved, so that the stable seepage of the coalbed methane reservoir is maintained, the stratum pressure can be dredged, and the depressurization and gas production efficiency can be improved.

Description

Fracturing fluid flowback control method and device for coalbed methane well

Technical Field

The present invention relates to the technical field of coalbed methane well production control, and in particular to a coalbed methane well fracturing fluid flowback control method, a coalbed methane well fracturing fluid flowback control device, a machine-readable storage medium and an electronic device.

Background technique

Coalbed methane is an important unconventional natural gas resource, and its gas production process is significantly different from that of conventional natural gas. The coalbed methane reservoir is a coal rock layer with low natural permeability and groundwater in the pores and fissures. In the development of coalbed methane, it is necessary to establish underground fluid seepage channels through reservoir fracturing and discharge groundwater to reduce reservoir pressure and allow coalbed methane to be desorbed and produced.

Due to the complex physical properties of coal seam reservoirs, low natural permeability and high sensitivity, abnormal conditions such as reservoir damage, formation blockage and water lock are prone to occur during the development process, resulting in lower reservoir permeability, insufficient desorption and decreased production capacity of coalbed methane wells, restricting the efficient construction and development of coalbed methane.

At present, the on-site control of coalbed methane wells mainly focuses on the liquid production during production, the rate of dynamic liquid level decline, changes in bottom hole pressure, etc., with the aim of maintaining stable production and avoiding reservoir damage. However, it is currently impossible to clearly determine the timing and rate of fracturing fluid return, and there is no uniform standard for on-site construction organization. Some wells are shut down for too long after fracturing, and the return efficiency is too low, resulting in coal powder sedimentation and reservoir damage, which greatly affects the gas efficiency and production capacity compliance rate of coalbed methane wells.

Summary of the invention

The purpose of the embodiments of the present invention is to provide a fracturing fluid return control method for a coalbed methane well, a fracturing fluid return control device for a coalbed methane well, a machine-readable storage medium and an electronic device. The fracturing fluid return control method for a coalbed methane well can adopt different control strategies to control the return rate in different fracturing fluid return control stages, so as to clarify the time node of the fracturing fluid return, help to systematically arrange on-site production processes and measures, help to relieve formation pressure, and improve the efficiency of pressure reduction and gas production.

In order to achieve the above-mentioned purpose, the first aspect of the present application provides a method for controlling the flowback of fracturing fluid in a coalbed methane well, comprising:

During the fracturing fluid flowback process of coalbed methane wells, real-time acquisition of wellhead pressure;

Based on the wellhead pressure, centrally determine the current fracturing fluid flowback control stage in the preset fracturing fluid flowback control stage;

Controlling the rate of fracturing fluid flowback based on the control strategy corresponding to the current fracturing fluid flowback control stage;

The preset fracturing fluid flowback control stage set includes a plurality of fracturing fluid flowback control stages and a plurality of control strategies corresponding to the plurality of fracturing fluid flowback control stages.

In the embodiment of the present application, each control strategy includes the size of the nozzle;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blowout controlled to control the fracturing fluid flowback rate.

In the embodiments of the present application, each control strategy includes a maximum flow rate;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback.

In the embodiment of the present application, each control strategy includes nozzle size and maximum flow rate;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blown out and controlled;

Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback.

In the embodiment of the present application, each fracturing fluid flowback control stage is respectively provided with a blowdown level, and the method further comprises:

In the case of sand production at the wellhead, adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy;

Based on the updated control strategy, the rate of fracturing fluid flowback is controlled.

In an embodiment of the present application, the method further includes:

Determining whether the wellhead pressure reaches a first threshold;

When it is determined that the wellhead pressure reaches the first threshold, a staged control strategy is adopted to control artificial lift and drainage.

In the embodiment of the present application, the staged control strategy is used to control artificial lift and drainage, including:

Get bottom hole pressure in real time;

Determining a current artificial lift production stage based on the desorption pressure and the bottom hole pressure;

Based on the current artificial lift production stage, the pressure drop rate is controlled.

In an embodiment of the present application, the method further includes:

Determine whether the coalbed methane well has entered the late stage of development;

When it is determined that the coalbed methane well has entered the late stage of development, the wellhead pressure is controlled to reach a preset pressure threshold range.

In the embodiment of the present application, the determination of whether the coalbed methane well has entered the late stage of development includes:

Acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable;

When it is determined that the bottom hole pressure remains stable, it is determined that the coalbed methane well has entered the late stage of development.

The second aspect of the present application provides a fracturing fluid flowback control device for a coalbed methane well, comprising:

An acquisition module is used to obtain the wellhead pressure in real time during the fracturing fluid flowback process of the coalbed methane well;

A determination module, configured to determine the current fracturing fluid flowback control stage in a preset fracturing fluid flowback control stage set based on the wellhead pressure; wherein the preset fracturing fluid flowback control stage set includes a plurality of fracturing fluid flowback control stages and a plurality of control strategies respectively corresponding to the plurality of fracturing fluid flowback control stages;

The first control module is used to control the rate of fracturing fluid flowback based on the control strategy corresponding to the current fracturing fluid flowback control stage.

In the embodiment of the present application, each control strategy includes the size of the nozzle;

The first control module comprises:

The blowout unit is used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid return control stage to control the rate of fracturing fluid return.

In the embodiments of the present application, each control strategy includes a maximum flow rate;

The first control module comprises:

The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return.

In the embodiment of the present application, each control strategy includes nozzle size and maximum flow rate;

The first control module comprises:

A blowout unit, used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage;

The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return.

In the embodiment of the present application, each fracturing fluid flowback control stage is respectively provided with a blowout level, and the device further comprises:

An adjustment module, used for adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy when sand is produced at the wellhead;

The second control module is used to control the flowback rate of the fracturing fluid based on the updated control strategy.

In the embodiment of the present application, the device further includes:

A first judgment module, used to judge whether the wellhead pressure reaches a first threshold;

The drainage module is used to control artificial lift drainage by adopting a staged control strategy when it is determined that the wellhead pressure reaches a first threshold.

In the embodiment of the present application, the drainage module includes:

A first pressure acquisition unit, used for acquiring bottom hole pressure in real time;

a drainage stage determination unit, configured to determine a current artificial lift drainage stage based on a desorption pressure and the bottom hole pressure;

A pressure drop control unit is used to control the pressure drop rate based on the current artificial lift drainage stage.

In the embodiment of the present application, the device further includes:

The second judgment module is used to judge whether the coalbed methane well has entered the late stage of development;

The third control module is used to control the wellhead pressure to reach a preset pressure threshold range when it is determined that the coalbed methane well has entered the late stage of development.

In the embodiment of the present application, the second determination module includes:

A second pressure acquisition unit, used to acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable;

The determination unit is used to determine that the coalbed methane well has entered the late stage of development when it is determined that the bottom hole pressure remains stable.

A third aspect of the present application provides an electronic device, the electronic device comprising:

at least one processor;

a memory connected to the at least one processor;

The memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the above-mentioned coalbed methane well fracturing fluid return control method by executing the instructions stored in the memory.

A fourth aspect of the present application provides a machine-readable storage medium having instructions stored thereon, which, when executed by a processor, configures the processor to execute the above-mentioned coalbed methane well fracturing fluid return control method.

Through the above technical scheme, during the fracturing fluid return process of the coalbed methane well, the wellhead pressure is obtained in real time, and based on the wellhead pressure, the current fracturing fluid return control stage is determined in the preset fracturing fluid return control stage set; wherein, the preset fracturing fluid return control stage set includes multiple fracturing fluid return control stages, and multiple control strategies corresponding to the multiple fracturing fluid return control stages, respectively, and the rate of fracturing fluid return is controlled based on the control strategy corresponding to the current fracturing fluid return control stage. By determining the current fracturing fluid return control stage, different control strategies can be used in different fracturing fluid return control stages to control the return rate, so that the time node of fracturing fluid return can be clarified, which is helpful to systematically arrange the on-site production process and measures, and the corresponding control strategy can clarify the fracturing fluid return production control measures, and the formation pressure increase caused by the formation energy supplemented by fracturing can be used to accelerate the return speed, improve the return efficiency, and flush the near-well contamination zone, so as to achieve the effect of dredging the formation seepage channel, thereby maintaining the stable seepage of the coalbed methane reservoir, helping to dredge the formation pressure and improve the pressure reduction gas production efficiency.

Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

FIG1 schematically shows a flow chart of a method for controlling fracturing fluid flowback in a coalbed methane well according to an embodiment of the present application;

FIG2 schematically shows a curve diagram of nozzle size and wellhead pressure according to an embodiment of the present application;

FIG3 schematically shows a schematic diagram of drainage-type coalbed methane fracturing fluid flowback and drainage gas production control according to an embodiment of the present application;

FIG4 schematically shows a structural diagram of a fracturing fluid flowback control device for a coalbed methane well according to an embodiment of the present application;

FIG5 schematically shows an internal structure diagram of a computer device according to an embodiment of the present application.

Description of Reference Numerals

410 - acquisition module; 420 - determination module; 430 - first control module; A01 - processor; A02 - network interface; A03 - internal memory; A04 - display screen; A05 - input device; A06 - non-volatile storage medium; B01 - operating system; B02 - computer program.

Detailed ways

The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

It should be noted that if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

Please refer to Figure 1, which schematically shows a flow chart of a method for controlling the flowback of fracturing fluid in a coalbed methane well according to an embodiment of the present application. This embodiment provides a method for controlling the flowback of fracturing fluid in a coalbed methane well, comprising the following steps:

Step 210: during the fracturing fluid flowback process of the coalbed methane well, obtaining the wellhead pressure in real time;

In this embodiment, after the pump stop pressure drop test of the coalbed methane well fracturing operation is completed, the fracturing fluid return work is immediately carried out, that is, the fracturing fluid return stage of the coalbed methane well is entered. The above-mentioned wellhead pressure can be obtained based on the data collected in real time by the wellhead pressure sensor.

Step 220: Based on the wellhead pressure, determine the current fracturing fluid flowback control stage in the preset fracturing fluid flowback control stage set; wherein the preset fracturing fluid flowback control stage set includes multiple fracturing fluid flowback control stages and multiple control strategies corresponding to the multiple fracturing fluid flowback control stages respectively;

In this embodiment, the number of the above-mentioned fracturing fluid return control stages can be determined according to the actual situation of the coalbed methane well. Different fracturing fluid return control stages adopt different control strategies. Different fracturing fluid return control stages correspond to different pressure ranges. When determining the current fracturing fluid return control stage, it can be determined by comparing the wellhead pressure with each pressure range to determine which pressure range it is in. The fracturing fluid return control stage corresponding to the pressure range is the current fracturing fluid return control stage. For example: the preset fracturing fluid return control stage includes four stages a, b, c, and d. The pressure range corresponding to stage a is greater than 10MPa, the pressure range corresponding to stage b is 5-10MPa, the pressure range corresponding to stage c is 2-5MPa, the pressure range corresponding to stage d is less than 2MPa, and the wellhead pressure is 3MPa. After comparison, it is determined that the current fracturing fluid return control stage is stage c. The above-mentioned fracturing fluid return control stage set can be pre-set, wherein each fracturing fluid return control stage corresponds to a corresponding control strategy, and the control strategy is used to control the rate of fracturing fluid return. By comparing the wellhead pressure with each pressure range to match the current fracturing fluid return control stage, the corresponding control strategy can be obtained accordingly.

Step 230: Based on the control strategy corresponding to the current fracturing fluid flowback control stage, control the fracturing fluid flowback rate.

In this embodiment, different fracturing fluid flowback control stages have different control strategies, and the control strategies are used to control the flowback rate of the fracturing fluid.

In the above implementation process, by determining the current fracturing fluid return control stage, different control strategies can be adopted in different fracturing fluid return control stages. Determining the current fracturing fluid return control stage means clarifying the time node of fracturing fluid return, which is helpful to systematically arrange on-site production processes and measures, and through the corresponding control strategy, the fracturing fluid return production control measures can be clarified, and the formation pressure increase caused by the formation energy supplemented by fracturing can be used to accelerate the return speed, improve the return efficiency, and flush the near-well contaminated zone, so as to achieve the effect of dredging the formation seepage channel, thereby maintaining stable seepage in the coalbed methane reservoir, helping to dredge the formation pressure and improve the pressure reduction gas production efficiency.

In some embodiments, in order to be able to control the rate of fracturing fluid return, it can be controlled by the nozzle size, that is, each control strategy includes the nozzle size; the control strategy corresponding to the current fracturing fluid return control stage controls the rate of fracturing fluid return, including the following steps: based on the nozzle size in the control strategy corresponding to the current fracturing fluid return control stage, the coalbed methane well is blown out to control the rate of fracturing fluid return.

In this embodiment, the nozzle size can be set in advance based on experience, and can be a range. For example: as shown in Figure 2, Figure 2 schematically shows a curve diagram of the nozzle size and wellhead pressure according to an embodiment of the present application. In the stage where the wellhead pressure is 5 to 10 MPa, the nozzle size can be between 7mm and 8mm, and in the stage where the wellhead pressure is 2 to 5MPa, the nozzle size can be between 10mm and 12mm. It should be noted that for ease of operation, a fixed value can also be directly taken. For example, in the above example, the average value, i.e. 7.5mm, can be directly taken. After determining the current fracturing fluid return control stage, the corresponding nozzle size can be obtained, and then the corresponding nozzle size is used to control the blowdown of the coalbed methane well, thereby controlling the rate of fracturing fluid return.

By setting the nozzle size in each control strategy, the rate of fracturing fluid return can be controlled by the nozzle size, which is more universal and convenient for use in various coalbed methane wells.

In some embodiments, in order to be able to control the rate of fracturing fluid return, the rate of fracturing fluid return can be controlled by the maximum flow rate, that is, each control strategy includes a maximum flow rate; the control strategy corresponding to the current fracturing fluid return control stage controls the rate of fracturing fluid return, including: based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, controls the flow rate of the coalbed methane well to control the rate of fracturing fluid return.

In this embodiment, the maximum flow rate can be preset based on experience. For example, when the wellhead pressure is greater than 10MPa, it is stage (a), and the maximum flow rate is controlled at ^20m3 /h; when the wellhead pressure is between 5 and 10MPa, it is stage (b), and the maximum flow rate is controlled at ^15m3 /h; when the wellhead pressure is between 2 and 5MPa, it is stage (c), and the maximum flow rate is controlled at ^10m3 /h; when the wellhead pressure is less than 2MPa, it is stage (d), and the maximum flow rate is controlled at ^5m3 /h.

By setting the maximum flow rate in each control strategy, it is more convenient to control the rate of fracturing fluid flowback by the maximum flow rate.

In some embodiments, in order to better control the rate of fracturing fluid flowback, the control can be performed from two directions: the nozzle size and the maximum flow rate. That is, each control strategy includes the nozzle size and the maximum flow rate. The control strategy corresponding to the current fracturing fluid flowback control stage controls the rate of fracturing fluid flowback, including the following steps:

Firstly, based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blowout controlled;

Then, based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the flowback rate of the fracturing fluid.

For example: when the wellhead pressure is >10MPa, it is stage (a), and a 5mm nozzle is used for spraying, and the maximum flow rate is controlled at ^20m3 /h; when the wellhead pressure is 5-10MPa, it is stage (b), and an 8mm nozzle is used for spraying, and the maximum flow rate is controlled at ^15m3 /h; when the wellhead pressure is 2-5MPa, it is stage (c), and a 10-12mm nozzle is used for spraying, and the maximum flow rate is controlled at ^10m3 /h; when the wellhead pressure is <2MPa, it is stage (d), and the nozzle is open for spraying, and the maximum flow rate is controlled at ^5m3 /h.

By controlling the two fracturing fluid flowback production control measures of nozzle size and maximum flow rate, the rate of fracturing fluid flowback can be better controlled.

In some embodiments, in order to avoid sand production during blowout, the control strategy can also be adjusted in time according to the sand production situation. Specifically, each fracturing fluid flowback control stage is respectively provided with a blowout level, and the method further includes the following steps:

Firstly, in the case of sand production at the wellhead, based on the blowout level of the current fracturing fluid flowback control stage, the current control strategy is adjusted to obtain an updated control strategy;

In this embodiment, when setting the blowout level, the blowout level can be set according to the nozzle size, that is, the smaller the nozzle size in the control strategy corresponding to the fracturing fluid return control stage, the greater the maximum flow rate, and the correspondingly higher the blowout level. In the above example, the blowout level of stage (a) is the highest, followed by stage (b), then stage (c), and finally stage (d). When adjusting the current control strategy, the blowout level can be adjusted to a lower level in sequence. For example, if the current fracturing fluid return control stage is stage (a), and sand is produced during the blowout at the wellhead, the control strategy can be adjusted to the control strategy corresponding to stage (b). If sand is still produced, continue to adjust the control strategy to the control strategy corresponding to stage (c) until no sand is produced.

Then, based on the updated control strategy, the rate of fracturing fluid flowback is controlled.

In this embodiment, after the current control strategy is adjusted, the flowback rate of the fracturing fluid can be controlled according to the updated control strategy to avoid sand production during blowout.

By timely adjusting the blowout level when sand is produced at the wellhead, sand production during blowout can be effectively avoided, ensuring the smooth return of the fracturing fluid.

In some embodiments, since there is no clear method to guide the implementation time and drainage rate of the drainage process after the fracturing fluid is returned, some wells are not drained in time after the return is completed, and the high pressure of the wellbore liquid column causes the reservoir to be blocked, and no continuous flow is formed, which is prone to reservoir damage. Therefore, after the fracturing fluid is returned, the drainage pump and the drainage pipe string can be put in to carry out artificial lifting and drainage. The method also includes the following steps:

First, determining whether the wellhead pressure reaches a first threshold;

In this embodiment, the first threshold value may be a value set according to actual conditions, and the first threshold value may be 0. The judgment of whether the wellhead pressure reaches the first threshold value may be to judge whether the wellhead pressure is 0, that is, when the wellhead has no self-flowing discharge capability, the fracturing fluid flowback ends.

Then, when it is determined that the wellhead pressure reaches the first threshold, a staged control strategy is adopted to control artificial lift drainage.

In this embodiment, when the wellhead has no self-flowing drainage capacity, the fracturing fluid backflow ends, and then artificial lifting and drainage are carried out, which can be specifically controlled by a staged control strategy. The staged control strategy can be pre-divided into multiple stages, and each stage corresponds to a different control strategy.

It should be noted that flowback and artificial lift drainage are continuous processes. The selection of drainage equipment and construction preparation should be carried out in advance, and there should be no waiting time for construction after flowback to avoid the sedimentation of coal powder due to stagnation of reservoir fluid, to maximize the continuous and stable output of formation fluid, to relieve formation pressure and to avoid reservoir pollution.

In some embodiments, in order to better control artificial lift drainage, the rate of decrease of bottom hole pressure can be controlled in stages during artificial lift drainage. Specifically, the artificial lift drainage is controlled by adopting a staged control strategy, including the following steps:

First, obtain bottom hole pressure in real time;

In this embodiment, the bottom hole pressure can be obtained by reading the value of the bottom hole pressure gauge during artificial lifting and drainage.

Then, based on the desorption pressure and the bottom hole pressure, the current artificial lift drainage stage is determined;

In this embodiment, the desorption pressure refers to the critical desorption pressure, which can be obtained in advance. The current artificial lift drainage stage can be determined by comparing the desorption pressure with the bottom hole pressure to obtain different stages, for example, when the bottom hole pressure > desorption pressure, it is stage (a), and when the bottom hole pressure ≤ desorption pressure, it is stage (b).

Finally, based on the current artificial lift drainage stage, the pressure drop rate is controlled.

In this embodiment, different pressure drop rates can be used for different artificial lift and drainage stages. For example, when the bottom hole pressure is greater than the desorption pressure, it is stage (a), and the pressure drop rate is controlled at 0.05-0.10 MPa/d. At this time, single-phase water flows, and the reservoir fluid flows continuously according to the bottom hole pressure; when the bottom hole pressure is less than or equal to the desorption pressure, it is stage (b), and the pressure drop rate is controlled at <0.01 MPa/d. At this time, the adsorbed gas begins to desorb, and the formation flows in a multiphase state. Keeping the bottom hole pressure slowly decreasing is conducive to the smooth transition between the water phase flow and the gas phase flow, and continuously dredges the formation to prevent water lock.

By determining the current artificial lift drainage stage based on the desorption pressure and the bottom hole pressure, and controlling the corresponding pressure drop rate, when the bottom hole pressure is greater than the desorption pressure, the reservoir fluid can be controlled to flow continuously according to the bottom hole pressure; when the bottom hole pressure is not greater than the desorption pressure, maintaining a slow drop in the bottom hole pressure is conducive to the smooth transition of water phase flow and gas phase flow, and continuously dredges the formation to prevent water lock. In this way, the time nodes and production control measures for drainage and gas production can be clearly defined, so as to facilitate the systematic arrangement of on-site production processes and measures, maintain stable seepage in the coalbed methane reservoir, dredge the formation pressure, and improve the efficiency of pressure reduction and gas production.

In some embodiments, due to the lack of formation energy in the later stage of coalbed methane well development, unstable and discontinuous water production, and the inability of formation pressure to drop continuously and stably, enhanced drainage can be carried out at this time, that is, negative pressure drainage equipment is installed at the wellhead to make the wellhead pressure reach the preset pressure threshold range. The method also includes the following steps:

First, determine whether the CBM well has entered the late stage of development;

In this embodiment, the above judgment process can be to judge whether the bottom hole pressure tends to be stable, and if the bottom hole pressure remains stable, it indicates that the coalbed methane well has entered the late stage of development. That is, the judgment of whether the coalbed methane well has entered the late stage of development includes: obtaining the bottom hole pressure in real time, and judging whether the bottom hole pressure remains stable; and if it is determined that the bottom hole pressure remains stable, it is determined that the coalbed methane well has entered the late stage of development.

Then, when it is determined that the coalbed methane well has entered the late stage of development, the wellhead pressure is controlled to reach a preset pressure threshold range.

In this embodiment, when the coalbed methane well enters the late stage of development, enhanced drainage is carried out, that is, negative pressure pumping equipment is installed at the wellhead to control the wellhead pressure to drop to a preset pressure threshold range. The above preset pressure threshold range can be set in advance according to actual conditions. For example: to the pressure threshold range of -1 to -3MPa, the wellhead pressure is controlled to drop to -1 to -3MPa, so as to further establish a production pressure difference to relieve the formation pressure, promote the continuous and stable flow of reservoir fluid, and release the reservoir flow potential.

By controlling the wellhead pressure to reach a preset pressure threshold range when the coalbed methane well enters the late stage of development, a production pressure difference is further established to relieve the formation pressure, promote continuous and stable flow of reservoir fluid, and release the reservoir flow potential.

Please refer to Figure 3, which schematically shows a schematic diagram of the drainage-type coalbed methane fracturing fluid return and drainage gas production control according to an embodiment of the present application. The entire control process includes fracturing fluid return, artificial lift drainage and enhanced drainage and production. By designing a systematic and comprehensive drainage-type coalbed methane fracturing fluid return and drainage gas production control program, as shown in Table 1 below, Table 1 is a drainage-type coalbed methane fracturing fluid return and drainage gas production control program. The control standard in Table 1 represents the corresponding control strategy, and the control node represents the control of each stage as a time node. The entire process includes fracturing fluid return, artificial lift drainage and production, and enhanced drainage and production, among which the fracturing fluid return corresponds to four stages, and the artificial lift drainage corresponds to two stages. The above-mentioned control program guides the continuous return and production of coalbed methane wells on site, which greatly improves the pressure reduction and desorption efficiency, avoids reservoir pollution, and improves the development effect of coalbed methane wells. This method has been applied in production in key basins for coalbed methane development, such as the Qinshui Basin. It has been implemented in about 207 vertical wells and about 150 horizontal wells. The average fracturing fluid return rate of the implemented wells has increased by 5% to 10%, and the gas discovery time has been shortened by 30%, greatly improving the efficiency of coalbed well development.

Table 1: Control procedures for drainage-type coalbed methane fracturing fluid flowback and drainage gas production

Take the An XX well area in the Anze block of the Qinshui Basin as an example:

After the fracturing pressure drop measurement is completed, the fluid is immediately released through the oil pipe. At the same time, a pumping unit is installed at the wellhead and the tubing pump is transported to the well site for standby. The fracturing fluid return is divided into four stages: (a), (b), (c), and (d). One and a half days after the return, artificial lift and production operations are carried out. The tubing is quickly raised and lowered without interruption. After the tubing pump is installed in place, pumping is started quickly. Artificial lift and production control the bottom hole pressure according to the two stages (a) and (b). Gas is quickly seen after 35 days of production. The entire return and production and pressure reduction construction is continuous, the liquid production is stable and continuous, the return rate reaches 45%, and the peak production capacity of a single well is 2,350 cubic meters/day, which is 30% higher than that of the old well.

In the above implementation process, the wellhead pressure is obtained in real time during the fracturing fluid return process of the coalbed methane well, and based on the wellhead pressure, the current fracturing fluid return control stage is determined in the preset fracturing fluid return control stage set; wherein, the preset fracturing fluid return control stage set includes multiple fracturing fluid return control stages, and multiple control strategies corresponding to the multiple fracturing fluid return control stages, respectively, and the rate of fracturing fluid return is controlled based on the control strategy corresponding to the current fracturing fluid return control stage. By determining the current fracturing fluid return control stage, different control strategies can be used in different fracturing fluid return control stages to control the return rate, so that the time node of fracturing fluid return can be clarified, which is helpful to systematically arrange the on-site production process and measures, and the corresponding control strategy can clarify the fracturing fluid return production control measures, and the formation pressure increase caused by the formation energy supplemented by fracturing can be used to accelerate the return speed, improve the return efficiency, and flush the near-well contamination zone, so as to achieve the effect of dredging the formation seepage channel, thereby maintaining the stable seepage of the coalbed methane reservoir, helping to dredge the formation pressure and improve the pressure reduction gas production efficiency. By timely adjusting the blowout level when sand is produced at the wellhead, sand can be effectively avoided during blowout, ensuring the smooth return of the fracturing fluid. After the return of the fracturing fluid is completed, a phased control strategy is adopted to control the artificial lift drainage, which can clarify the time nodes and production control measures for drainage and gas production, so as to facilitate the systematic arrangement of on-site production processes and measures, maintain stable seepage of the coalbed methane reservoir, dredge the formation pressure, and improve the efficiency of pressure reduction and gas production. By controlling the wellhead pressure to reach the preset pressure threshold range when the coalbed methane well enters the late stage of development, further establishing a production pressure difference to dredge the formation pressure, promoting the continuous and stable flow of the reservoir fluid, and releasing the flow potential of the reservoir. The dredging fracturing fluid return and drainage gas production control method is realized, so that it can guide the timing and rate of coalbed methane well return and drainage, improve the efficiency of pressure reduction and desorption to avoid reservoir damage, and achieve the purpose of improving the on-site development effect of coalbed methane.

FIG. 1 is a flow chart of a method for controlling the return of fracturing fluid in a coalbed methane well in one embodiment. It should be understood that, although the steps in the flow chart of FIG. 1 are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and these steps can be executed in other orders. Moreover, at least a portion of the steps in FIG. 1 may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and the execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a portion of the sub-steps or stages of other steps.

Please refer to Figure 4, which schematically shows a structural diagram of a fracturing fluid flowback control device for a coalbed methane well according to an embodiment of the present application. This embodiment provides a fracturing fluid flowback control device for a coalbed methane well, including an acquisition module 410, a determination module 420 and a first control module 430, wherein:

The acquisition module 410 is used to obtain the wellhead pressure in real time during the fracturing fluid flowback process of the coalbed methane well;

A determination module 420 is used to determine the current fracturing fluid flowback control stage in a preset fracturing fluid flowback control stage set based on the wellhead pressure; wherein the preset fracturing fluid flowback control stage set includes multiple fracturing fluid flowback control stages and multiple control strategies corresponding to the multiple fracturing fluid flowback control stages respectively;

The first control module 430 is used to control the fracturing fluid flowback rate based on the control strategy corresponding to the current fracturing fluid flowback control stage.

Among them, each control strategy includes the size of the nozzle;

The first control module 430 includes:

The blowout unit is used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid return control stage to control the rate of fracturing fluid return.

Among them, each control strategy includes a maximum flow rate;

The first control module 430 includes:

The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return.

Among them, each control strategy includes nozzle size and maximum flow rate;

The first control module 430 includes:

A blowout unit, used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage;

The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return.

Wherein, each fracturing fluid flowback control stage is respectively provided with a blowout level, and the device further comprises:

An adjustment module, used for adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy when sand is produced at the wellhead;

The second control module is used to control the flowback rate of the fracturing fluid based on the updated control strategy.

Wherein, the device further comprises:

A first judgment module, used to judge whether the wellhead pressure reaches a first threshold;

The drainage module is used to control artificial lift drainage by adopting a staged control strategy when it is determined that the wellhead pressure reaches a first threshold.

Wherein, the drainage module includes:

A first pressure acquisition unit, used for acquiring bottom hole pressure in real time;

a drainage stage determination unit, configured to determine a current artificial lift drainage stage based on a desorption pressure and the bottom hole pressure;

A pressure drop control unit is used to control the pressure drop rate based on the current artificial lift drainage stage.

Wherein, the device further comprises:

The second judgment module is used to judge whether the coalbed methane well has entered the late stage of development;

The third control module is used to control the wellhead pressure to reach a preset pressure threshold range when it is determined that the coalbed methane well has entered the late stage of development.

Wherein, the second judgment module includes:

A second pressure acquisition unit, used to acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable;

The determination unit is used to determine that the coalbed methane well has entered the late stage of development when it is determined that the bottom hole pressure remains stable.

The fracturing fluid return control device for the coalbed methane well includes a processor and a memory. The acquisition module 410, the determination module 420 and the first control module 430 are all stored in the memory as program units, and the processor executes the program units stored in the memory to realize the corresponding functions.

The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the timing and rate of fracturing fluid return can be determined by adjusting kernel parameters.

The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and/or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

An embodiment of the present invention provides a machine-readable storage medium on which a program is stored. When the program is executed by a processor, the method for controlling the return flow of fracturing fluid in a coalbed methane well is implemented.

An embodiment of the present invention provides a processor, which is used to run a program, wherein the program executes the coalbed methane well fracturing fluid return control method when running.

In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be shown in FIG5 . The computer device includes a processor A01, a network interface A02, a display screen A04, an input device A05, and a memory (not shown in the figure) connected via a system bus. Among them, the processor A01 of the computer device is used to provide computing and control capabilities. The memory of the computer device includes an internal memory A03 and a non-volatile storage medium A06. The non-volatile storage medium A06 stores an operating system B01 and a computer program B02. The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 in the non-volatile storage medium A06. The network interface A02 of the computer device is used to communicate with an external terminal via a network connection. When the computer program is executed by the processor A01, a fracturing fluid return control method for a coalbed methane well is implemented. The display screen A04 of the computer device can be a liquid crystal display screen or an electronic ink display screen, and the input device A05 of the computer device can be a touch layer covering the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse.

Those skilled in the art will understand that the structure shown in FIG. 5 is merely a block diagram of a partial structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

In one embodiment, the fracturing fluid flowback control device for a coalbed methane well provided in the present application can be implemented in the form of a computer program, and the computer program can be run on a computer device as shown in FIG5. The memory of the computer device can store various program modules constituting the fracturing fluid flowback control device for a coalbed methane well, such as the acquisition module 410, the determination module 420, and the first control module 430 shown in FIG4. The computer program composed of various program modules enables the processor to execute the steps of the fracturing fluid flowback control method for a coalbed methane well in various embodiments of the present application described in this specification.

The computer device shown in FIG5 can execute step 210 through the acquisition module 410 in the fracturing fluid flowback control device of the coalbed methane well shown in FIG4. The computer device can execute step 220 through the determination module 420. The computer device can execute step 230 through the first control module 430.

The embodiment of the present application provides an electronic device, which includes: at least one processor; a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the above-mentioned coalbed methane well fracturing fluid return control method by executing the instructions stored in the memory. When the processor executes the instructions, the following steps are implemented:

During the fracturing fluid flowback process of coalbed methane wells, real-time acquisition of wellhead pressure;

Based on the wellhead pressure, centrally determine the current fracturing fluid flowback control stage in the preset fracturing fluid flowback control stage;

Controlling the rate of fracturing fluid flowback based on the control strategy corresponding to the current fracturing fluid flowback control stage;

The preset fracturing fluid flowback control stage set includes a plurality of fracturing fluid flowback control stages and a plurality of control strategies corresponding to the plurality of fracturing fluid flowback control stages.

In one embodiment, each control strategy includes nozzle size;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blowout controlled to control the fracturing fluid flowback rate.

In one embodiment, each control strategy includes a maximum flow rate;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback.

In one embodiment, each control strategy includes nozzle size and maximum flow rate;

The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including:

Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blown out and controlled;

Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback.

In one embodiment, each fracturing fluid flowback control stage is respectively provided with a blowdown level, and the method further comprises:

In the case of sand production at the wellhead, adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy;

Based on the updated control strategy, the rate of fracturing fluid flowback is controlled.

In one embodiment, the method further comprises:

Determining whether the wellhead pressure reaches a first threshold;

When it is determined that the wellhead pressure reaches the first threshold, a staged control strategy is adopted to control artificial lift and drainage.

In one embodiment, the use of a phased control strategy to control artificial lift drainage includes:

Get bottom hole pressure in real time;

Determining a current artificial lift production stage based on the desorption pressure and the bottom hole pressure;

Based on the current artificial lift production stage, the pressure drop rate is controlled.

In one embodiment, the method further comprises:

Determine whether the coalbed methane well has entered the late stage of development;

When it is determined that the coalbed methane well has entered the late stage of development, the wellhead pressure is controlled to reach a preset pressure threshold range.

In one embodiment, determining whether the coalbed methane well has entered the late stage of development includes:

Acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable;

When it is determined that the bottom hole pressure remains stable, it is determined that the coalbed methane well has entered the late stage of development.

Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

The present application is described with reference to the flowchart and/or block diagram of the method, device (system) and computer program product according to the embodiment of the present application. It should be understood that each process and/or box in the flowchart and/or block diagram, and the combination of the process and/or box in the flowchart and/or block diagram can be realized 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 produce a device for realizing the function specified in one process or multiple processes in the flowchart and/or one box or multiple boxes in the block diagram.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and/or one or more boxes in the block diagram.

In a typical configuration, a computing device includes one or more processors (CPU), input/output interfaces, network interfaces, and memory.

The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and/or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims (20)

1. A method for controlling fracturing fluid flowback in a coalbed methane well, comprising: During the fracturing fluid flowback process of coalbed methane wells, real-time acquisition of wellhead pressure; Based on the wellhead pressure, centrally determine the current fracturing fluid flowback control stage in the preset fracturing fluid flowback control stage; Controlling the rate of fracturing fluid flowback based on the control strategy corresponding to the current fracturing fluid flowback control stage; The preset fracturing fluid flowback control stage set includes a plurality of fracturing fluid flowback control stages and a plurality of control strategies corresponding to the plurality of fracturing fluid flowback control stages. 2. The method for controlling the flowback of fracturing fluid in a coalbed methane well according to claim 1, characterized in that each control strategy includes the size of the nozzle; The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including: Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blowout controlled to control the fracturing fluid flowback rate. 3. The method for controlling the flowback of fracturing fluid in a coalbed methane well according to claim 1, wherein each control strategy includes a maximum flow rate; The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including: Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback. 4. The method for controlling the flowback of fracturing fluid in a coalbed methane well according to claim 1, wherein each control strategy includes a nozzle size and a maximum flow rate; The control strategy corresponding to the current fracturing fluid flowback control stage is used to control the flowback rate of the fracturing fluid, including: Based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage, the coalbed methane well is blown out and controlled; Based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid flowback control stage, the flow rate of the coalbed methane well is controlled to control the rate of fracturing fluid flowback. 5. The method for controlling the flowback of fracturing fluid in a coalbed methane well according to claim 2, characterized in that each flowback control stage of the fracturing fluid is respectively provided with a blowdown level, and the method further comprises: In the case of sand production at the wellhead, adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy; Based on the updated control strategy, the rate of fracturing fluid flowback is controlled. 6. The method for controlling fracturing fluid flowback in a coalbed methane well according to claim 1, characterized in that the method further comprises: Determining whether the wellhead pressure reaches a first threshold; When it is determined that the wellhead pressure reaches the first threshold, a staged control strategy is adopted to control artificial lift and drainage. 7. The method for controlling the flowback of fracturing fluid in a coalbed methane well according to claim 6, characterized in that the artificial lift and drainage are controlled by adopting a staged control strategy, comprising: Get bottom hole pressure in real time; Determining a current artificial lift production stage based on the desorption pressure and the bottom hole pressure; Based on the current artificial lift production stage, the pressure drop rate is controlled. 8. The method for controlling fracturing fluid flowback in a coalbed methane well according to claim 6, characterized in that the method further comprises: Determine whether the coalbed methane well has entered the late stage of development; When it is determined that the coalbed methane well has entered the late stage of development, the wellhead pressure is controlled to reach a preset pressure threshold range. 9. The method for controlling fracturing fluid flowback of a coalbed methane well according to claim 8, wherein the step of judging whether the coalbed methane well has entered the late stage of development comprises: Acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable; When it is determined that the bottom hole pressure remains stable, it is determined that the coalbed methane well has entered the late stage of development. 10. A fracturing fluid flowback control device for a coalbed methane well, characterized by comprising: An acquisition module is used to obtain the wellhead pressure in real time during the fracturing fluid flowback process of the coalbed methane well; A determination module, configured to determine the current fracturing fluid flowback control stage in a preset fracturing fluid flowback control stage set based on the wellhead pressure; wherein the preset fracturing fluid flowback control stage set includes a plurality of fracturing fluid flowback control stages and a plurality of control strategies respectively corresponding to the plurality of fracturing fluid flowback control stages; The first control module is used to control the rate of fracturing fluid flowback based on the control strategy corresponding to the current fracturing fluid flowback control stage. 11. The fracturing fluid flowback control device for a coalbed methane well according to claim 10, characterized in that each control strategy includes the size of the oil nozzle; The first control module comprises: The blowout unit is used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid return control stage to control the rate of fracturing fluid return. 12. The fracturing fluid flowback control device for a coalbed methane well according to claim 10, characterized in that each control strategy includes a maximum flow rate; The first control module comprises: The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return. 13. The fracturing fluid flowback control device for a coalbed methane well according to claim 10, characterized in that each control strategy includes a nozzle size and a maximum flow rate; The first control module comprises: A blowout unit, used to control the blowout of the coalbed methane well based on the nozzle size in the control strategy corresponding to the current fracturing fluid flowback control stage; The flow rate unit is used to control the flow rate of the coalbed methane well based on the maximum flow rate in the control strategy corresponding to the current fracturing fluid return control stage, so as to control the rate of fracturing fluid return. 14. The fracturing fluid flowback control device for a coalbed methane well according to claim 11, characterized in that each fracturing fluid flowback control stage is respectively provided with a blowout level, and the device further comprises: An adjustment module, used for adjusting the current control strategy based on the blowout level of the current fracturing fluid flowback control stage to obtain an updated control strategy when sand is produced at the wellhead; The second control module is used to control the flowback rate of the fracturing fluid based on the updated control strategy. 15. The fracturing fluid flowback control device for a coalbed methane well according to claim 10, characterized in that the device further comprises: A first judgment module, used to judge whether the wellhead pressure reaches a first threshold; The drainage module is used to adopt a step-by-step method when it is determined that the wellhead pressure reaches a first threshold. The segment control strategy controls artificial lift drainage. 16. The fracturing fluid flowback control device for a coalbed methane well according to claim 15, characterized in that the drainage module comprises: A first pressure acquisition unit, used for acquiring bottom hole pressure in real time; a drainage stage determination unit, configured to determine a current artificial lift drainage stage based on a desorption pressure and the bottom hole pressure; A pressure drop control unit is used to control the pressure drop rate based on the current artificial lift drainage stage. 17. The fracturing fluid flowback control device for a coalbed methane well according to claim 15, characterized in that the device further comprises: The second judgment module is used to judge whether the coalbed methane well has entered the late stage of development; The third control module is used to control the wellhead pressure to reach a preset pressure threshold range when it is determined that the coalbed methane well has entered the late stage of development. 18. The fracturing fluid flowback control device for a coalbed methane well according to claim 17, wherein the second judgment module comprises: A second pressure acquisition unit, used to acquire the bottom hole pressure in real time and determine whether the bottom hole pressure remains stable; The determination unit is used to determine that the coalbed methane well has entered the late stage of development when it is determined that the bottom hole pressure remains stable. 19. An electronic device, characterized in that the electronic device comprises: at least one processor; a memory connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the method for controlling the return flow of fracturing fluid in a coalbed methane well as described in any one of claims 1 to 9 by executing the instructions stored in the memory. 20. A machine-readable storage medium having instructions stored thereon, wherein when the instructions are executed by a processor, the processor is configured to execute the fracturing fluid backflow control method for a coalbed methane well according to any one of claims 1 to 9.