CN112780235B

CN112780235B - Drainage and production control method, device, control equipment and storage medium for coal-bed gas well

Info

Publication number: CN112780235B
Application number: CN201911061135.8A
Authority: CN
Inventors: 胡秋嘉; 张光波; 刘春春; 贾慧敏; 毛崇昊; 祁空军; 樊彬; 李俊; 张庆; 刘昌平; 何军; 李学博
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2019-11-01
Filing date: 2019-11-01
Publication date: 2023-01-10
Anticipated expiration: 2039-11-01
Also published as: CN112780235A

Abstract

The application discloses a drainage and production control method and device of a coal-bed gas well, control equipment and a storage medium, and belongs to the technical field of oil gas. The method comprises the following steps: in the process of extracting coal bed gas in a coal bed gas well, determining the amount of fracturing fluid entering the coal bed, the desorption pressure of a first target coal bed, the desorption pressure and the bottom hole flowing pressure of a second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed; determining the current drainage and production stage of the coal-bed gas well according to the amount of the fracturing fluid entering the coal bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed; and selecting the corresponding depressurization speed to carry out drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well. The method and the device can determine the drainage and production stage of the coal gas layer well, select a proper depressurization speed to conduct drainage and production, and improve the accuracy and timeliness of drainage and production.

Description

Drainage and production control method and device for coal-bed gas well, control equipment and storage medium

Technical Field

The application relates to the technical field of oil gas, in particular to a method, a device and equipment for controlling drainage and production of a coal-bed gas well and a storage medium.

Background

Coal bed gas is hydrocarbon gas existing in coal beds and coal-series stratums and is high-quality clean energy. At present, the drainage and the production of the coal bed gas well can be carried out by a double-layer combined production mode, and when the drainage and the production of the coal bed gas are carried out, the core is to control the bottom flowing pressure, and the flowing pressure drop amplitude is controlled by controlling the casing pressure and the liquid column pressure in a shaft.

However, since the control of the cuff pressure requires manual adjustment on site by workers, the accuracy and timeliness of the cuff pressure adjustment are easily affected by manual adjustment and environmental weather influence. And the control of the liquid column pressure in the shaft is realized by adjusting the drainage and production depressurization speed, and if the drainage and production depressurization speed and the timing are set inappropriately, the damage to a coal reservoir can be caused, and the release of the productivity of the coal-bed gas well can be inhibited.

Disclosure of Invention

The application provides a drainage and production control method, a drainage and production control device, control equipment and a storage medium for a coal-bed gas well, and can solve the problem that a coal reservoir is damaged due to inaccurate and untimely drainage and production control in the related technology. The technical scheme is as follows:

in one aspect, a drainage and production control method for a coal bed gas well is provided, and the method comprises the following steps:

in the process of extracting coal bed gas in a coal bed gas well, determining the amount of fracturing fluid entering the coal bed, the desorption pressure of a first target coal bed, the desorption pressure and the bottom hole flowing pressure of a second target coal bed, and the liquid column pressure between the first target coal bed and the second target coal bed, wherein the first target coal bed and the second target coal bed are any two coal beds in a plurality of coal beds of a stratum, and the burial depth of the first target coal bed is smaller than the burial depth of the second target coal bed;

determining the current drainage and production stage of the coal-bed gas well according to the amount of the fracturing fluid entering the coal-bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed;

and selecting a corresponding pressure reduction speed to carry out drainage and pressure reduction on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well.

In some embodiments, the determining the amount of fracturing fluid into the coal seam fluid comprises:

acquiring total fracturing fluid amounts and total flowback fluid amounts of the first target coal seam and the second target coal seam;

and subtracting the total flowback liquid amount from the total fracturing liquid amount to obtain the coal bed liquid amount of the fracturing liquid.

In some embodiments, the determining the bottom hole flow pressure of the second target coal seam and the fluid column pressure between the first target coal seam and the second target coal seam comprises:

acquiring the burial depth of the first target coal seam, the burial depth of the second target coal seam and the bottom hole flowing pressure of the second target coal seam;

subtracting the burial depth of the first target coal seam from the burial depth of the second target coal seam to obtain a burial depth distance between the first target coal seam and the second target coal seam;

and dividing the burial depth interval by a preset constant to obtain the liquid column pressure between the first target coal seam and the second target coal seam.

In some embodiments, the determining the drainage stage of the coalbed methane well at present according to the amount of the fracturing fluid entering the coalbed methane, the desorption pressure of the first target coalbed, the desorption pressure and the bottom hole flow pressure of the second target coalbed, and the liquid column pressure between the first target coalbed and the second target coalbed comprises:

after the fracturing fluid in the coal-bed gas well is injected, determining that the coal-bed gas well is in a fracturing fluid flowback stage;

when the coal-bed gas well is in the fracturing fluid flowback stage, obtaining the fluid yield of the coal-bed gas well;

when the liquid production amount is larger than or equal to the amount of the fracturing liquid entering the coal bed, if the bottom hole flow pressure of the second target coal bed is larger than the sum of the desorption pressure of the first target coal bed and the liquid column pressure, determining that the coal bed gas well is in a drainage depressurization stage;

if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the sum of the desorption pressure of the first target coal seam and the liquid column pressure and is larger than the desorption pressure of the second target coal seam, determining that the coal seam gas well is in the stages of pressure control and gas production of the first target coal seam and water drainage and pressure reduction of the second target coal seam;

if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the desorption pressure of the second target coal seam and larger than the liquid column pressure, determining that the coal-bed gas well is in a pressure-controlled gas production stage of the first target coal seam and the second target coal seam;

if the bottom hole flowing pressure of the second target coal seam is less than or equal to the column fluid pressure and is greater than a preset pressure reduction threshold value, determining that the coal seam gas well is in a first target coal seam stable yield stage and a second target coal seam pressure control gas production stage;

and if the bottom hole flowing pressure of the second target coal seam is less than or equal to the preset pressure reduction threshold value, determining that the coal seam gas well is in a stable yield stage of the first target coal seam and the second target coal seam.

In some embodiments, the selecting, according to the current drainage and production stage of the coal-bed gas well, a corresponding depressurization speed to perform drainage and depressurization on the coal-bed gas well to realize drainage and production control on the coal-bed gas well includes:

when the coal bed gas well is in a fracturing fluid flowback stage, selecting a first depressurization speed to carry out drainage depressurization;

when the coal-bed gas well is in a drainage depressurization stage, selecting a second depressurization speed to carry out drainage depressurization, wherein the second depressurization speed is less than the first depressurization speed;

when the coal-bed gas well is in the first target coal-bed pressure-control gas production and second target coal-bed drainage pressure reduction stage, selecting a third pressure reduction speed for drainage pressure reduction, wherein the third pressure reduction speed is smaller than the second pressure reduction speed;

when the coal-bed gas well is in the pressure-controlled gas production stage of the first target coal bed and the second target coal bed, selecting a fourth pressure reduction speed to drain water and reduce pressure, wherein the fourth pressure reduction speed is less than the third pressure reduction speed;

when the coal-bed gas well is in a first target coal-bed stable yield stage and a second target coal-bed pressure-control gas production stage, selecting a fifth pressure reduction speed to drain water and reduce pressure, wherein the difference value between the fifth pressure reduction speed and the third pressure reduction speed is smaller than or equal to a speed threshold value;

and when the coal bed gas well is in a stable yield stage of a first target coal bed and a second target coal bed, maintaining the bottom hole flowing pressure of the second target coal bed so as to carry out coal bed gas drainage and mining.

In another aspect, a drainage and production control device for a coal-bed gas well is provided, the device includes:

the system comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining the amount of fracturing fluid entering a coal seam, the desorption pressure of a first target coal seam, the desorption pressure and the bottom hole flowing pressure of a second target coal seam and the liquid column pressure between the first target coal seam and the second target coal seam in the process of discharging and extracting the coal seam gas in a coal seam gas well, the first target coal seam and the second target coal seam are any two coal seams in a plurality of coal seams of a stratum, and the burial depth of the first target coal seam is smaller than the burial depth of the second target coal seam;

the second determination module is used for determining the current drainage and production stage of the coal-bed gas well according to the amount of the fracturing fluid entering the coal-bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed;

and the selection module is used for selecting the corresponding pressure reduction speed to carry out drainage and pressure reduction on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well.

In some embodiments, the first determining module comprises:

the first obtaining sub-module is used for obtaining the total fracturing fluid amount and the total flowback fluid amount of the first target coal seam and the second target coal seam;

and the first calculation submodule is used for subtracting the total flowback liquid amount from the total fracturing liquid amount to obtain the coal bed liquid amount of the fracturing liquid.

In some embodiments, the first determining module comprises:

the second obtaining sub-module is used for obtaining the burial depth of the first target coal seam, the burial depth of the second target coal seam and the bottom hole flowing pressure of the second target coal seam;

the second calculation submodule is used for subtracting the burial depth of the first target coal seam from the burial depth of the second target coal seam to obtain a burial depth distance between the first target coal seam and the second target coal seam;

and the third calculation submodule is used for dividing the burial depth interval by a preset constant to obtain the liquid column pressure between the first target coal seam and the second target coal seam.

In some embodiments, the root second determination module is to:

if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the sum of the desorption pressure of the first target coal seam and the liquid column pressure and is larger than the desorption pressure of the second target coal seam, determining that the coal-bed gas well is in the stages of controlling pressure and producing gas of the first target coal seam and draining and depressurizing the second target coal seam;

if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the desorption pressure of the second target coal seam and larger than the liquid column pressure, determining that the coal seam gas well is in a pressure-controlled gas production stage of the first target coal seam and the second target coal seam;

and if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the preset depressurization threshold value, determining that the coal seam gas well is in a first target coal seam and a second target coal seam stable production stage.

In some embodiments, the selection module is to:

when the coal-bed gas well is in the pressure-controlled gas production stage of the first target coal bed and the second target coal bed, selecting a fourth pressure reduction speed for draining water and reducing pressure, wherein the fourth pressure reduction speed is less than the third pressure reduction speed;

and when the coal bed gas well is in a first target coal bed and a second target coal bed stable production stage, maintaining the current bottom hole flowing pressure of the second target coal bed so as to carry out coal bed gas drainage and mining.

In another aspect, a control device is provided, where the control device includes a memory and a processor, the memory is used for storing a computer program, and the processor is used for executing the computer program stored in the memory to implement the steps of the drainage and production control method for a coal-bed gas well.

In another aspect, a computer-readable storage medium is provided, and the storage medium stores a computer program, and the computer program is executed by a processor to implement the steps of the drainage and production control method for the coal-bed gas well.

In another aspect, a computer program product containing instructions is provided, which when run on a computer, causes the computer to perform the steps of the method for controlling drainage and production of a coal bed gas well as described above.

The technical scheme provided by the application can at least bring the following beneficial effects:

in the application, the drainage and production stage of the coal bed gas well can be determined, and the drainage and production can be carried out by selecting the proper depressurization speed, so that the drainage and depressurization efficiency is greatly improved, and the gas production rate of the coal bed gas double-layer combined production well is improved. Meanwhile, the flowing pressure at the bottom of the well is indirectly controlled by controlling the pressure reduction speed, so that the conditions that the gas phase permeability is increased and the water phase permeability is reduced to influence the reduction of the desorption area in the gas-water two-phase flow stage after the desorption of the coal bed due to the suppressed casing pressure are improved, the accuracy and timeliness of the control influenced by reasons such as mountainous regions, rain and snow weather are also improved, the field operation is reduced, and the production cost is saved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic illustration of an implementation environment provided by an embodiment of the present application;

FIG. 2 is a flowchart of a drainage and production control method for a coal-bed gas well according to an embodiment of the present disclosure;

FIG. 3 is a flow chart of another method for controlling drainage and production of a coal-bed gas well according to an embodiment of the application;

FIG. 4 is a schematic structural diagram of a drainage and production control device of a coal-bed gas well provided by an embodiment of the application;

fig. 5 is a schematic structural diagram of a first determining module provided in an embodiment of the present application;

fig. 6 is a schematic structural diagram of another first determining module provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a control device provided in an embodiment of the present application;

fig. 8 is a schematic structural diagram of another control device provided in an embodiment of the present application.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Before explaining the drainage and production control method of the coal-bed gas well provided by the embodiment of the application in detail, an application scenario and an implementation environment provided by the embodiment of the application are introduced.

First, an application scenario related to the embodiment of the present application is described.

At present, the drainage and production of the coal bed gas well can be carried out by a double-layer combined production mode, and when the drainage and production of the coal bed gas are carried out, the core is to control the bottom flowing pressure, and the flowing pressure drop amplitude is controlled by controlling the casing pressure and the liquid column pressure in a shaft.

However, since the control of the cuff pressure requires manual adjustment on site by workers, the accuracy and timeliness of the cuff pressure adjustment are easily affected by manual adjustment and environmental weather influence. And the liquid column pressure in the shaft is controlled by adjusting the drainage and production depressurization speed, and if the drainage and production depressurization speed and the timing are set inappropriately, not only can the coal reservoir be damaged, but also the release of the productivity of the coal-bed gas well can be inhibited.

Based on the scene, the method for controlling the drainage and production of the coal-bed gas well improves the accuracy and timeliness of the drainage and production control of the coal-bed gas well.

Next, an implementation environment related to the embodiments of the present application will be described.

Referring to fig. 1, fig. 1 is a schematic diagram illustrating an implementation environment in accordance with an example embodiment. The implementation environment comprises at least one control device for controlling the gas-formation well to discharge and produce, the control device comprises at least one terminal 101 and/or a server 102, and the terminal 101 can be in communication connection with the server 102. The communication connection may be a wired or wireless connection, which is not limited in this application.

The terminal 101 may be any electronic product capable of performing human-Computer interaction with a user through one or more modes such as a keyboard, a touch pad, a touch screen, a remote controller, voice interaction or handwriting equipment, for example, a PC (Personal Computer), a mobile phone, a smart phone, a PDA (Personal Digital Assistant), a wearable device, a Pocket PC (Pocket PC), a tablet Computer, a smart car machine, a smart television, a smart sound box, and the like.

The server 102 may be a server, a server cluster composed of a plurality of servers, or a cloud computing service center.

Those skilled in the art will appreciate that the terminal 101 and the server 102 are only examples, and other existing or future terminals or servers may be suitable for the application, and are included within the scope of the present application and are incorporated by reference herein.

Next, a drainage and production control method for a coal-bed gas well provided by the embodiments of the present application will be explained in detail with reference to the accompanying drawings.

Fig. 2 is a flowchart of a drainage and production control method for a coal-bed gas well, which is provided by an embodiment of the present application and is applied to a control device. Referring to fig. 2, the method includes the following steps.

Step 201: in the process of extracting coal bed gas in a coal bed gas well, determining the amount of fracturing fluid entering the coal bed, the desorption pressure of a first target coal bed, the desorption pressure and the bottom hole flowing pressure of a second target coal bed, and the liquid column pressure between the first target coal bed and the second target coal bed, wherein the first target coal bed and the second target coal bed are any two coal beds in a plurality of coal beds of a stratum, and the burial depth of the first target coal bed is smaller than the burial depth of the second target coal bed.

Step 202: and determining the current drainage and production stage of the coal-bed gas well according to the amount of the fracturing fluid entering the coal-bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed.

Step 203: and selecting the corresponding depressurization speed to carry out drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well.

In the application, the drainage and production stage of the coal bed gas well can be determined, and the drainage and production can be carried out by selecting the proper depressurization speed, so that the drainage and depressurization efficiency is greatly improved, and the gas production rate of the coal bed gas double-layer combined production well is improved. Meanwhile, the flowing pressure at the bottom of the well is indirectly controlled by controlling the depressurization speed, so that the conditions that the gas-phase permeability is increased and the water-phase permeability is reduced to influence the reduction of the desorption area in the gas-water two-phase flow stage after the desorption of the coal bed due to the suppressed casing pressure are improved, the accuracy and timeliness of the control influenced by mountainous regions, rainy and snowy weather and the like are also improved, the field operation is reduced, and the production cost is saved.

In some embodiments, determining the amount of fracturing fluid into the coal seam fluid comprises:

In some embodiments, determining the bottom hole flow pressure of the second target coal seam, and the fluid column pressure between the first target coal seam and the second target coal seam, comprises:

In some embodiments, determining the drainage stage of the coalbed methane well at present according to the amount of the fracturing fluid entering the coalbed methane, the desorption pressure of the first target coalbed, the desorption pressure and the bottom hole flow pressure of the second target coalbed, and the liquid column pressure between the first target coalbed and the second target coalbed comprises:

when the liquid production amount is larger than or equal to the amount of the fracturing liquid entering the coal bed, if the bottom hole flowing pressure of the second target coal bed is larger than the sum of the desorption pressure of the first target coal bed and the liquid column pressure, determining that the coal bed gas well is in a drainage depressurization stage;

if the bottom hole flowing pressure of the second target coal seam is less than or equal to the sum of the desorption pressure of the first target coal seam and the liquid column pressure and is greater than the desorption pressure of the second target coal seam, determining that the coal-bed gas well is in the stages of controlling pressure and producing gas of the first target coal seam and draining and depressurizing the second target coal seam;

if the bottom hole flowing pressure of the second target coal seam is less than or equal to the desorption pressure of the second target coal seam and is greater than the liquid column pressure, determining that the coal-bed gas well is in a pressure-controlled gas production stage of the first target coal seam and the second target coal seam;

if the bottom hole flowing pressure of the second target coal seam is less than or equal to the column liquid pressure and is greater than a preset pressure reduction threshold value, determining that the coal seam gas well is in a first target coal seam stable yield stage and a second target coal seam pressure control gas production stage;

In some embodiments, selecting a corresponding depressurization speed to perform drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well to realize drainage and production control of the coal-bed gas well includes:

when the coal bed gas well is in a drainage depressurization stage, selecting a second depressurization speed to carry out drainage depressurization, wherein the second depressurization speed is less than the first depressurization speed;

when the coal bed gas well is in the first target coal bed pressure control gas production stage and the second target coal bed water drainage pressure reduction stage, selecting a third pressure reduction speed to drain water and reduce pressure, wherein the third pressure reduction speed is lower than the second pressure reduction speed;

when the coal-bed gas well is in a first target coal-bed stable yield stage and a second target coal-bed pressure-control gas production stage, selecting a fifth pressure reduction speed for draining water and reducing pressure, wherein the difference value between the fifth pressure reduction speed and the third pressure reduction speed is less than or equal to a speed threshold value;

and when the coal bed gas well is in the stable yield stage of the first target coal bed and the second target coal bed, maintaining the bottom hole flowing pressure of the current second target coal bed so as to discharge and produce the coal bed gas.

All the above optional technical solutions can be combined arbitrarily to form an optional embodiment of the present application, and the present application embodiment is not described in detail again.

Fig. 3 is a flowchart of a drainage and production control method for a coal-bed gas well according to an embodiment of the present disclosure, and referring to fig. 3, the method includes the following steps.

Step 301, in the process of extracting coal bed gas in a coal bed gas well, determining the amount of fracturing fluid entering the coal bed, the desorption pressure of a first target coal bed, the desorption pressure and bottom hole flowing pressure of a second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed by control equipment.

Because when the coal bed gas is extracted from the coal bed gas well, multiple sets of coal beds can be developed on common stratums, different coal beds have different desorption pressures, bottom flowing pressures and the like, and the coal bed gas can be extracted in a double-layer combined extraction mode when the coal bed gas is extracted. Therefore, in the process of extracting the coal bed gas in the coal bed gas well, the control device can determine the amount of the fracturing fluid entering the coal bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed, and the liquid column pressure between the first target coal bed and the second target coal bed.

It should be noted that, in the drainage and mining process, drainage and mining are performed in an open system production valve non-suffocating casing pressure drainage and mining mode.

It should be further noted that the first target coal seam and the second target coal seam are any two coal seams of the plurality of coal seams of the formation, and the burial depth of the first target coal seam is smaller than the burial depth of the second target coal seam. For example, the first target coal seam may be a layer 3 coal seam, the second target coal seam may be a layer 15 coal seam, and so on.

As an example, the operation of the control device to determine the amount of fracturing fluid into the coal seam fluid may be: acquiring total fracturing fluid amounts and total flowback fluid amounts of a first target coal seam and a second target coal seam; and subtracting the total flowback liquid amount from the total fracturing liquid amount to obtain the coal bed liquid amount of the fracturing liquid.

Because the fracturing fluid is generally required to be injected into the coal seam during the drainage and mining of the coal seam gas, and the fracturing fluid can enter the fracturing fluid flowback stage of the coal seam gas after the injection of the fracturing fluid is finished, the control equipment is required to acquire the total fracturing fluid amount and the total flowback of the first target coal seam and the second target coal seam in the drainage and mining process of the coal seam gas in the coal seam gas wellAnd subtracting the total flowback liquid amount from the total fracturing liquid amount to obtain the coal bed liquid amount of the fracturing liquid. This process is formulated as: v _{Entering a well} ＝V _Fracturing -V _{Back flow} ，V _{Entering a well} Amount of fracturing fluid introduced into the coal seam _Fracturing Is the total fracturing fluid volume, V _{Back flow} The total amount of the flowback liquid.

As an example, the operation of the control device to determine the bottom hole flow pressure of the second target coal seam, and the fluid column pressure between the first target coal seam and the second target coal seam may be: acquiring the burial depth of a first target coal seam, the burial depth of a second target coal seam and the bottom hole flowing pressure of the second target coal seam; subtracting the burial depth of the first target coal seam from the burial depth of the second target coal seam to obtain a burial depth distance between the first target coal seam and the second target coal seam; and dividing the burial depth distance by a preset constant to obtain the liquid column pressure between the first target coal seam and the second target coal seam.

Because when the distance is inequality between coal seam and the coal seam, the liquid column pressure also can be inequality, for example, the liquid column pressure between 2 nd layer coal seam and the 9 th layer coal seam is inequality with the liquid column pressure between 3 rd layer coal seam and the 15 th layer coal seam, and the bottom hole flowing pressure that is in the coal seam on different layers is also inequality, consequently, in order to accurate row of carrying out mining control to the coal seam gas well, the bottom hole flowing pressure of second target coal seam to and the liquid column pressure between first target coal seam and the second target coal seam need be confirmed to controlgear.

It should be noted that the bottom hole flowing pressure of the second target coal seam can be measured by the measuring equipment. For example, a bottom hole flow pressure meter is installed at the second target coal seam, and the bottom hole flow pressure of the second target coal seam can be monitored through the bottom hole flow pressure meter. The burial depth of the first target coal seam and the burial depth of the second target coal seam can be obtained through well logging interpretation results, for example, the burial depth of the first target coal seam is H ₃ The second target coal seam has a burial depth H ₁₅ Then the burial depth spacing H between the first target coal seam and the second target coal seam _c ＝H ₁₅ -H ₃ 。

The liquid column pressure between the first target coal seam and the second target coal seam is basically not changed for the same wellAnd converting, wherein the liquid column pressure between the first target coal seam and the second target coal seam is related to the burial depth distance between the first target coal seam and the second target coal seam, and therefore, the burial depth distance can be divided by a preset constant to obtain the liquid column pressure between the first target coal seam and the second target coal seam. The predetermined constant may be set in advance, for example, the predetermined constant may be 100, and then the liquid column pressure P _c ＝H _c /100。

In some embodiments, in the target area for coalbed methane production, the control device may monitor the reservoir pressure according to a coalbed methane exploration well or an evaluation well, and calculate desorption pressures of the first target coal bed and the second target coal bed in the target area according to the gas content test data. Alternatively, the control device may compile a contour map based on the desorption pressure values of the developed wells, and obtain the desorption pressures of the first target coal seam and the second target coal seam by a difference method.

And 302, determining the current drainage and production stage of the coal-bed gas well by the control equipment according to the amount of the fracturing fluid entering the coal-bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed.

The drainage and production control on the coal-bed gas well can comprise a plurality of drainage and production stages, and the control operation corresponding to each stage is different, so that the control equipment determines the current drainage and production stage of the coal-bed gas well according to the amount of the fracturing fluid entering the coal bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed.

As an example, the operation of the control device determining the drainage and production stage of the coal-bed gas well at present according to the amount of the fracturing fluid entering the coal bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed, and the liquid column pressure between the first target coal bed and the second target coal bed may be: after the fracturing fluid in the coal-bed gas well is injected, determining that the coal-bed gas well is in a fracturing fluid flowback stage; when the coal bed gas well is in a fracturing fluid flowback stage, obtaining the fluid yield of the coal bed gas well; when the liquid production is larger thanOr the amount of the fracturing fluid entering the coal seam fluid, if the bottom hole flowing pressure of the second target coal seam is more than the sum (P) of the desorption pressure and the fluid column pressure of the first target coal seam>P ₃ +P _c ) Determining that the coal bed gas well is in a drainage depressurization stage; if the bottom hole flow pressure of the second target coal seam is less than or equal to the sum of the desorption pressure and the liquid column pressure of the first target coal seam and is greater than the desorption pressure (P) of the second target coal seam ₁₅ <P≤P ₃ +P _c ) Determining that the coal bed gas well is in a first target coal bed pressure control gas production stage and a second target coal bed drainage pressure reduction stage; if the bottom hole flow pressure of the second target coal seam is less than or equal to the desorption pressure of the second target coal seam and is greater than the liquid column pressure (P) _c <P≤P ₁₅ ) Determining that the coal bed gas well is in a pressure control gas production stage of a first target coal bed and a second target coal bed; if the bottom hole flowing pressure of the second target coal seam is less than or equal to the column fluid pressure (P is less than or equal to P) _c ) If the pressure of the coal bed gas well is greater than the preset pressure reduction threshold, determining that the coal bed gas well is in a first target coal bed stable yield stage and a second target coal bed pressure control gas production stage; and if the bottom hole flowing pressure of the second target coal seam is less than or equal to the preset pressure reduction threshold value, determining that the coal seam gas well is in the stable yield stage of the first target coal seam and the second target coal seam.

In general, after the injection of the fracturing fluid is finished, the coal-bed gas is discharged and extracted, and the fracturing fluid is returned, so that the control equipment can determine that the coal-bed gas well is in the fracturing fluid returning stage only after the control equipment determines that the injection of the fracturing fluid in the coal-bed gas well is finished. And after entering the fracturing fluid flowback stage, the well fracturing fluid in the coal gas layer well is discharged into the well, and enters another drainage stage when the certain degree is reached, so that the control equipment can obtain the liquid yield of the coal gas well when the coal gas well is in the fracturing fluid flowback stage, and can continuously determine the drainage stage of the coal gas well through the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flow pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed after the liquid yield is greater than or equal to the liquid yield of the fracturing fluid into the coal bed.

It should be noted that the preset depressurization threshold may be set in advance according to requirements, and for example, may be 0.2 to 0.3Mpa (megapascal) or the like.

And 303, selecting a corresponding pressure reduction speed by the control equipment to carry out drainage and pressure reduction on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well.

Because the control equipment is different in control operation on the coal-bed gas well in different drainage and production stages, the control equipment selects the corresponding pressure reduction speed to carry out drainage and pressure reduction on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well.

As an example, the control device selects a corresponding depressurization speed to perform drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well, so as to implement drainage and production control of the coal-bed gas well, and the operation may be: when the coal bed gas well is in a fracturing fluid flowback stage, selecting a first depressurization speed to perform drainage depressurization; when the coal bed gas well is in a drainage depressurization stage, a second depressurization speed is selected for drainage depressurization, and the second depressurization speed is smaller than the first depressurization speed; when the coal bed gas well is in the first target coal bed pressure control gas production stage and the second target coal bed water drainage pressure reduction stage, selecting a third pressure reduction speed to drain water and reduce pressure, wherein the third pressure reduction speed is lower than the second pressure reduction speed; when the coal bed gas well is in a pressure control and gas production stage of a first target coal bed and a second target coal bed, selecting a fourth pressure reduction speed to drain water and reduce pressure, wherein the fourth pressure reduction speed is less than the third pressure reduction speed; when the coal bed gas well is in a first target coal bed stable yield stage and a second target coal bed pressure control gas production stage, selecting a fifth pressure reduction speed to drain water and reduce pressure, wherein the difference value between the fifth pressure reduction speed and the third pressure reduction speed is smaller than or equal to a speed threshold value; and when the coal bed gas well is in the stable yield stage of the first target coal bed and the second target coal bed, maintaining the bottom hole flowing pressure of the current second target coal bed so as to discharge and produce the coal bed gas.

When the coal-bed gas well is in the fracturing fluid flowback stage, in order to discharge and discharge the well fracturing fluid as much as possible, drainage depressurization is required to be performed at a first depressurization speed, which can be set in advance and can be set according to the number of layers of a first target coal seam and a second target coal seam, for example, when the first target coal seam is a 3 rd coal seam and the second target coal seam is a 15 th coal seam, the first depressurization speed can be between 0.1 and 0.15MPa/d (megapascal/day).

When the coal-bed gas well is in a drainage depressurization stage, the two layers of target coal beds are not desorbed in the stage, and in order to increase the expansion range of the dewatering funnel, the descending speed of the liquid column in the shaft is properly reduced. Therefore, the draining depressurization can be performed at the second depressurization rate. The second depressurization speed can also be set in advance and can be set according to the number of layers of the first target coal seam and the second target coal seam, for example, when the first target coal seam is a 3 rd-layer coal seam and the second target coal seam is a 15 th-layer coal seam, the second depressurization speed can be between 0.05 and 0.07 MPa/d.

When the coal-bed gas well is in the stages of controlling pressure and producing gas of the first target coal bed and draining and depressurizing the second target coal bed, the first target coal bed is desorbed and produces gas, and the second target coal bed is still in the stages of draining and depressurizing. Therefore, the draining depressurization can be performed at the third depressurization rate. The third depressurization speed may be set in advance, and may be set according to the number of layers where the first target coal seam and the second target coal seam are located, for example, when the first target coal seam is a 3 rd coal seam and the second target coal seam is a 15 th coal seam, the third depressurization speed may be between 0.03 MPa/d and 0.05 MPa/d.

When the coal-bed gas well is in the pressure control gas production stage of the first target coal bed and the second target coal bed, the first target coal bed and the second target coal bed are desorbed to produce gas, and in order to keep the gas production trend, the descending speed of a liquid column in the shaft is reduced. Therefore, the draining depressurization can be performed at the fourth depressurization rate. This fourth depressurization speed can set up in advance, and can set up according to the number of piles that first target coal seam and second target coal seam are located, for example, when this first target coal seam is 3 rd floor's coal seam, the second target coal seam is 15 th floor's coal seam, fourth depressurization speed can be between 0.01-0.02 MPa/d.

When the coal-bed gas well is in a first target coal bed stable yield and second target coal bed pressure-control gas production stage, the working fluid level in the shaft is lowered to be below a first target coal bed section and above a second target coal bed section, the first target coal bed is exposed without production-improving capacity, the gas production is improved mainly by the second target coal bed, and the pressure-reducing speed is properly increased in order to keep the gas production trend. Therefore, the draining depressurization can be performed at the fifth depressurization rate. The fifth depressurization speed is equivalent to the third depressurization speed, that is, the fifth depressurization speed may be the same as or similar to the third depressurization speed, and the fifth depressurization speed may be set in advance and may be set according to the number of layers where the first target coal seam and the second target coal seam are located, for example, when the first target coal seam is a 3 rd coal seam and the second target coal seam is a 15 th coal seam, the fifth depressurization speed may be between 0.03 and 0.05 MPa/d. The speed threshold may be set in advance, for example, the speed threshold may be between 0.0-0.2 MPa/d.

When the coal bed gas well is in the stable production stage of the first target coal bed and the second target coal bed, the coal bed gas is discharged and produced only by stabilizing the bottom hole flowing pressure.

Step 304: in the process of controlling the drainage and production of the coal-bed gas well, the control equipment reminds the current drainage and production stage and the pressure reduction speed of the coal-bed gas well.

In order to enable workers to know the current state of the coal-bed gas well, the control equipment reminds the current drainage and production stage and the pressure reduction speed of the coal-bed gas well.

As an example, the control device may prompt the current drainage and production stage and the pressure reduction speed of the coal-bed gas well in a manner of displaying information and/or in a manner of playing information in voice.

In the embodiment of the application, the drainage and production stage of the coal bed gas well can be determined, and the drainage and production can be carried out by selecting the proper depressurization speed, so that the drainage and depressurization efficiency is greatly improved, and the gas production rate of the coal bed gas double-layer combined production well is improved. Meanwhile, the flowing pressure at the bottom of the well is indirectly controlled by controlling the pressure reduction speed, so that the conditions that the gas phase permeability is increased and the water phase permeability is reduced to influence the reduction of the desorption area in the gas-water two-phase flow stage after the desorption of the coal bed due to the suppressed casing pressure are improved, the accuracy and timeliness of the control influenced by reasons such as mountainous regions, rain and snow weather are also improved, the field operation is reduced, and the production cost is saved.

After explaining the drainage and production control method of the coal-bed gas well provided in the embodiment of the present application, a drainage and production control device of the coal-bed gas well provided in the embodiment of the present application is introduced next.

Fig. 4 is a schematic structural diagram of a drainage and production control device of a coal-bed gas well provided by an embodiment of the present application, where the drainage and production control device of the coal-bed gas well may be implemented by software, hardware, or a combination of the two as part or all of a control device, and the control device may be a terminal or a server shown in fig. 1. Referring to fig. 4, the apparatus includes: a first determining module 401, a second determining module 402 and a selecting module 403.

The first determining module 401 is configured to determine, in a process of extracting coal bed gas in a coal bed gas well, an amount of a fracturing fluid entering the coal bed, a desorption pressure of a first target coal bed, a desorption pressure and a bottom hole flowing pressure of a second target coal bed, and a fluid column pressure between the first target coal bed and the second target coal bed, where the first target coal bed and the second target coal bed are any two coal beds in a plurality of coal beds of a formation, and a burial depth of the first target coal bed is smaller than a burial depth of the second target coal bed;

a second determining module 402, configured to determine a drainage stage of the coal-bed gas well at present according to the amount of the fracturing fluid entering the coal-bed, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed, and a fluid column pressure between the first target coal bed and the second target coal bed;

and the selecting module 403 is configured to select a corresponding depressurization speed to perform drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well, so as to implement drainage and production control on the coal-bed gas well.

In some embodiments, referring to fig. 5, the first determining module 401 comprises:

the first obtaining sub-module 4011 is configured to obtain a total fracturing fluid amount and a total flowback fluid amount of the first target coal seam and the second target coal seam;

the first calculation submodule 4012 is configured to subtract the total flowback liquid amount from the total fracturing liquid amount to obtain the amount of the fracturing liquid entering the coal seam liquid.

In some embodiments, referring to fig. 6, the first determining module 401 comprises:

the second obtaining sub-module 4013 is configured to obtain the burial depth of the first target coal seam, the burial depth of the second target coal seam, and the bottom-hole flowing pressure of the second target coal seam;

the second calculation submodule 4014 is configured to subtract the burial depth of the first target coal seam from the burial depth of the second target coal seam to obtain a burial depth distance between the first target coal seam and the second target coal seam;

and the third calculation sub module 4015 is configured to divide the burial depth distance by a preset constant to obtain a liquid column pressure between the first target coal seam and the second target coal seam.

In some embodiments, the root second determining module 402 is configured to:

In some embodiments, the selection module 403 is configured to:

when the coal-bed gas well is in a fracturing fluid flowback stage, selecting a first depressurization speed to perform drainage depressurization;

and when the coal-bed gas well is in a first target coal bed and a second target coal bed stable yield stage, maintaining the current bottom flowing pressure of the second target coal bed to carry out coal-bed gas drainage and mining.

It should be noted that: in the drainage and production control device for the coal-bed gas well provided by the embodiment, when the coal-bed gas well is drained and produced, only the division of each functional module is exemplified, and in practical application, the function distribution can be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules, so as to complete all or part of the functions described above. In addition, the coal-bed gas well drainage and production control device provided by the embodiment and the coal-bed gas well drainage and production control method embodiment belong to the same concept, and the specific implementation process is described in detail in the method embodiment and is not described again.

Fig. 7 is a block diagram of a control device according to an embodiment of the present application. The control device may be a portable mobile terminal, such as: a tablet computer, a notebook computer, or a desktop computer. The control device may also be referred to by other names such as user equipment, portable terminal, laptop terminal, desktop terminal, etc.

Generally, the control device includes: a processor 701 and a memory 702.

The processor 701 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and so on. The processor 701 may be implemented in at least one hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 701 may also include a main processor and a coprocessor, where the main processor is a processor for Processing data in an awake state, and is also called a Central Processing Unit (CPU); a coprocessor is a low power processor for processing data in a standby state. In some embodiments, the processor 701 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the display screen. In some embodiments, the processor 701 may further include an AI (Artificial Intelligence) processor for processing computing operations related to machine learning.

Memory 702 may include one or more computer-readable storage media, which may be non-transitory. Memory 702 may also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In some embodiments, a non-transitory computer readable storage medium in the memory 702 is configured to store at least one instruction for execution by the processor 701 to implement a method for controlling drainage of a coalbed methane well as provided by method embodiments of the present application.

In some embodiments, the control device may further include: a peripheral interface 703 and at least one peripheral. The processor 701, the memory 702, and the peripheral interface 703 may be connected by buses or signal lines. Various peripheral devices may be connected to the peripheral interface 703 via a bus, signal line, or circuit board. Specifically, the peripheral device includes: at least one of radio frequency circuitry 704, touch display 705, camera 706, audio circuitry 707, positioning components 708, and power source 709.

The peripheral interface 703 may be used to connect at least one peripheral device related to I/O (Input/Output) to the processor 701 and the memory 702. In some embodiments, processor 701, memory 702, and peripheral interface 703 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 701, the memory 702, and the peripheral interface 703 may be implemented on a separate chip or circuit board, which is not limited in this embodiment.

The Radio Frequency circuit 704 is used to receive and transmit RF (Radio Frequency) signals, also known as electromagnetic signals. The radio frequency circuitry 704 communicates with communication networks and other communication devices via electromagnetic signals. The rf circuit 704 converts an electrical signal into an electromagnetic signal to transmit, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 704 comprises: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and so forth. The radio frequency circuitry 704 may communicate with other terminals via at least one wireless communication protocol. The wireless communication protocols include, but are not limited to: the world wide web, metropolitan area networks, intranets, various generations of mobile communication networks (2G, 3G, 4G, and 5G), wireless local area networks, and/or WiFi (Wireless Fidelity) networks. In some embodiments, the radio frequency circuit 704 may further include NFC (Near Field Communication) related circuits, which are not limited in this application.

The display screen 705 is used to display a UI (User Interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display screen 705 is a touch display screen, the display screen 705 also has the ability to capture touch signals on or above the surface of the display screen 705. The touch signal may be input to the processor 701 as a control signal for processing. At this point, the display screen 705 may also be used to provide virtual buttons and/or a virtual keyboard, also referred to as soft buttons and/or a soft keyboard. In some embodiments, the display 705 may be one, providing a front panel of the control device; in other embodiments, the display 705 may be at least two, respectively disposed on different surfaces of the control device or in a folded design; in still other embodiments, the display 705 may be a flexible display, disposed on a curved surface or on a folding surface of the control device. Even more, the display 705 may be arranged in a non-rectangular irregular pattern, i.e. a shaped screen. The Display 705 may be made of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), or the like.

The camera assembly 706 is used to capture images or video. Optionally, the camera assembly 706 includes a front camera and a rear camera. Generally, a front camera is disposed at a front panel of the terminal, and a rear camera is disposed at a rear surface of the terminal. In some embodiments, the number of the rear cameras is at least two, and each rear camera is any one of a main camera, a depth-of-field camera, a wide-angle camera and a telephoto camera, so that the main camera and the depth-of-field camera are fused to realize a background blurring function, the main camera and the wide-angle camera are fused to realize panoramic shooting and a VR (Virtual Reality) shooting function or other fusion shooting functions. In some embodiments, camera assembly 706 may also include a flash. The flash lamp can be a monochrome temperature flash lamp or a bicolor temperature flash lamp. The double-color-temperature flash lamp is a combination of a warm-light flash lamp and a cold-light flash lamp, and can be used for light compensation at different color temperatures.

The audio circuitry 707 may include a microphone and a speaker. The microphone is used for collecting sound waves of a user and the environment, converting the sound waves into electric signals, and inputting the electric signals to the processor 701 for processing or inputting the electric signals to the radio frequency circuit 704 to realize voice communication. For the purpose of stereo sound collection or noise reduction, a plurality of microphones may be provided at different portions of the control device, respectively. The microphone may also be an array microphone or an omni-directional acquisition microphone. The speaker is used to convert electrical signals from the processor 701 or the radio frequency circuit 704 into sound waves. The loudspeaker can be a traditional film loudspeaker or a piezoelectric ceramic loudspeaker. When the speaker is a piezoelectric ceramic speaker, the speaker can be used for purposes such as converting an electric signal into a sound wave audible to a human being, or converting an electric signal into a sound wave inaudible to a human being to measure a distance. In some embodiments, the audio circuitry 707 may also include a headphone jack.

The positioning component 708 is used to locate the current geographic Location of the controlling device for navigation or LBS (Location Based Service). The Positioning component 708 can be a Positioning component based on the Global Positioning System (GPS) in the united states, the beidou System in china, or the galileo System in russia.

The power supply 709 is used to supply power to various components in the control device. The power source 709 may be alternating current, direct current, disposable batteries, or rechargeable batteries. When the power source 709 includes a rechargeable battery, the rechargeable battery may be a wired rechargeable battery or a wireless rechargeable battery. The wired rechargeable battery is a battery charged through a wired line, and the wireless rechargeable battery is a battery charged through a wireless coil. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, the control device also includes one or more sensors 710. The one or more sensors 710 include, but are not limited to: acceleration sensor 711, gyro sensor 712, pressure sensor 713, fingerprint sensor 714, optical sensor 715, and proximity sensor 716.

The acceleration sensor 711 can detect the magnitude of acceleration in three coordinate axes of a coordinate system established with the control apparatus. For example, the acceleration sensor 711 may be used to detect components of the gravitational acceleration in three coordinate axes. The processor 701 may control the touch screen 705 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 711. The acceleration sensor 711 may also be used for acquisition of motion data of a game or a user.

The gyro sensor 712 may detect a body direction and a rotation angle of the control device, and the gyro sensor 712 may acquire a 3D motion of the user on the control device in cooperation with the acceleration sensor 711. From the data collected by the gyro sensor 712, the processor 701 may implement the following functions: motion sensing (such as changing the UI according to a user's tilting operation), image stabilization while shooting, game control, and inertial navigation.

Pressure sensors 713 may be disposed on the side bezel of the control device and/or underneath the touch display screen 705. When the pressure sensor 713 is arranged on the side frame of the control device, a holding signal of a user to the control device can be detected, and the processor 701 performs left-right hand identification or quick operation according to the holding signal acquired by the pressure sensor 713. When the pressure sensor 713 is disposed at a lower layer of the touch display 705, the processor 701 controls the operability control on the UI interface according to the pressure operation of the user on the touch display 705. The operability control comprises at least one of a button control, a scroll bar control, an icon control, and a menu control.

The fingerprint sensor 714 is used for collecting a fingerprint of a user, and the processor 701 identifies the identity of the user according to the fingerprint collected by the fingerprint sensor 714, or the fingerprint sensor 714 identifies the identity of the user according to the collected fingerprint. When the user identity is identified as a trusted identity, the processor 701 authorizes the user to perform relevant sensitive operations, including unlocking a screen, viewing encrypted information, downloading software, paying, changing settings, and the like. Fingerprint sensor 714 may be provided to control the front, back, or sides of the device. When a physical button or vendor Logo is provided on the control device, the fingerprint sensor 714 may be integrated with the physical button or vendor Logo.

The optical sensor 715 is used to collect the ambient light intensity. In one embodiment, the processor 701 may control the display brightness of the touch display 705 based on the ambient light intensity collected by the optical sensor 715. Specifically, when the ambient light intensity is high, the display brightness of the touch display screen 705 is increased; when the ambient light intensity is low, the display brightness of the touch display 705 is turned down. In another embodiment, the processor 701 may also dynamically adjust the shooting parameters of the camera assembly 706 according to the ambient light intensity collected by the optical sensor 715.

A proximity sensor 716, also called a distance sensor, is usually arranged on the front panel of the control device. The proximity sensor 716 is used to capture the distance between the user and the front of the control device. In one embodiment, the processor 701 controls the touch display screen 705 to switch from the bright screen state to the dark screen state when the proximity sensor 716 detects that the distance between the user and the front face of the control device is gradually decreased; when the proximity sensor 716 detects that the distance between the user and the front of the control device is gradually increasing, the processor 701 controls the touch display screen 705 to switch from the breath screen state to the bright screen state.

Those skilled in the art will appreciate that the configuration shown in fig. 7 does not constitute a limitation of the control device and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components may be employed.

Fig. 8 is a schematic structural diagram of another control device provided in an embodiment of the present application. The control device may be a server 800, the server 800 including a Central Processing Unit (CPU) 801, a system memory 804 including a Random Access Memory (RAM) 802 and a Read Only Memory (ROM) 803, and a system bus 805 connecting the system memory 804 and the central processing unit 801. The server 800 also includes a basic input/output system (I/O system) 806, which facilitates transfer of information between devices within the computer, and a mass storage device 807 for storing an operating system 813, application programs 814, and other program modules 815.

The basic input/output system 806 includes a display 808 for displaying information and an input device 809 such as a mouse, keyboard, etc. for user input of information. Wherein a display 808 and an input device 809 are connected to the central processing unit 801 through an input output controller 810 connected to the system bus 805. The basic input/output system 806 may also include an input/output controller 810 for receiving and processing input from a number of other devices, such as a keyboard, mouse, or electronic stylus. Similarly, the input-output controller 810 also provides output to a display screen, a printer, or other type of output device.

The mass storage device 807 is connected to the central processing unit 801 through a mass storage controller (not shown) connected to the system bus 805. The mass storage device 807 and its associated computer-readable media provide non-volatile storage for the server 800. That is, the mass storage device 807 may include a computer-readable medium (not shown) such as a hard disk or CD-ROM drive.

Without loss of generality, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes RAM, ROM, EPROM, EEPROM, flash memory or other solid state storage technology, CD-ROM, DVD, or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices. Of course, those skilled in the art will appreciate that computer storage media is not limited to the foregoing. The system memory 804 and mass storage 807 described above may be collectively referred to as memory.

According to various embodiments of the application, the server 800 may also operate as a remote computer connected to a network through a network, such as the Internet. That is, the server 800 may be connected to the network 812 through the network interface unit 811 coupled to the system bus 805, or may be connected to other types of networks or remote computer systems (not shown) using the network interface unit 811.

The memory also includes one or more programs, which are stored in the memory and configured to be executed by the CPU.

In some embodiments, a computer-readable storage medium is further provided, where the storage medium stores a computer program, and the computer program, when executed by a processor, implements the steps of the method for controlling drainage and production of a coal-bed gas well in the above embodiments. For example, the computer readable storage medium may be a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.

It is noted that the computer-readable storage medium referred to herein may be a non-volatile storage medium, in other words, a non-transitory storage medium.

It should be understood that all or part of the steps for implementing the above embodiments may be implemented by software, hardware, firmware or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. The computer instructions may be stored in the computer-readable storage medium described above.

That is, in some embodiments, there is also provided a computer program product containing instructions which, when run on a computer, cause the computer to perform the steps of the method for controlling drainage and production of a coal-bed gas well as described above.

The above-mentioned embodiments are provided by way of example and should not be construed as limiting the present application, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A drainage and production control method for a coal-bed gas well is characterized by comprising the following steps:

selecting a corresponding depressurization speed to carry out drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well;

determining the current drainage and production stage of the coal-bed gas well according to the fracturing fluid inflow amount, the desorption pressure of the first target coal bed, the desorption pressure and the bottom hole flowing pressure of the second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed, and including:

if the bottom hole flowing pressure of the second target coal seam is smaller than or equal to the liquid column pressure and larger than a preset pressure reduction threshold value, determining that the coal seam gas well is in a first target coal seam stable yield stage and a second target coal seam pressure control gas production stage;

2. The method of claim 1, wherein determining the amount of fracturing fluid into the coal seam fluid comprises:

3. The method of claim 1, wherein the determining the bottom hole flow pressure of the second target coal seam and the fluid column pressure between the first target coal seam and the second target coal seam comprises:

4. The method of claim 1 or 3, wherein the step of selecting the corresponding depressurization speed to carry out drainage depressurization on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well comprises the following steps:

when the coal-bed gas well is in the first target coal-bed pressure control gas production stage and the second target coal-bed water drainage pressure reduction stage, selecting a third pressure reduction speed to drain water and reduce pressure, wherein the third pressure reduction speed is smaller than the second pressure reduction speed;

5. A drainage and production control device for a coal-bed gas well is characterized by comprising:

the device comprises a first determination module, a second determination module and a control module, wherein the first determination module is used for determining the amount of fracturing fluid entering the coal bed, the desorption pressure of a first target coal bed, the desorption pressure and the bottom hole flowing pressure of a second target coal bed and the liquid column pressure between the first target coal bed and the second target coal bed in the process of extracting the coal bed gas in the coal bed gas well, the first target coal bed and the second target coal bed are any two coal beds in a plurality of coal beds of a stratum, and the burial depth of the first target coal bed is smaller than the burial depth of the second target coal bed;

the selection module is used for selecting the corresponding pressure reduction speed to carry out drainage and pressure reduction on the coal-bed gas well according to the current drainage and production stage of the coal-bed gas well so as to realize drainage and production control on the coal-bed gas well;

the second determination module is to:

6. The apparatus of claim 5, wherein the first determining module comprises:

and the first calculation submodule is used for subtracting the total flowback liquid amount from the total fracturing liquid amount to obtain the amount of the fracturing liquid entering the coal bed.

7. The apparatus of claim 5, wherein the first determining module comprises:

and the third calculation submodule is used for dividing the burial depth distance by a preset constant to obtain the liquid column pressure between the first target coal seam and the second target coal seam.

8. The apparatus of claim 5, wherein the selection module is to:

when the coal-bed gas well is in a first target coal-bed stable yield stage and a second target coal-bed pressure-control gas production stage, selecting a fifth depressurization speed to drain water and depressurize, wherein the difference value between the fifth depressurization speed and the third depressurization speed is less than or equal to a speed threshold value;

9. A control device, characterized in that the control device comprises a memory for storing a computer program and a processor for executing the computer program stored in the memory for carrying out the steps of the method according to any one of the preceding claims 1 to 4.

10. A computer-readable storage medium, characterized in that a computer program is stored in the storage medium, which computer program, when being executed by a processor, carries out the steps of the method of one of the claims 1 to 4.