Method and device for determining production mode of deep coalbed methane well

Abstract

The embodiment of the application provides a method and device for determining a production mode of a deep coalbed methane well, which comprises the following steps: determining a water-gas ratio and a bottom hole pressure at any production time according to the water-gas ratio and the bottom hole pressure at the initial stable gas production time, the production days after the initial stable gas production, and a preset water-gas ratio and production day change prediction model and a bottom hole pressure and production day change prediction model; determining a production pressure coefficient curve under different water-gas ratios according to the water-gas ratio and the bottom hole pressure at the any production time, and determining a critical pressure coefficient curve of self-flowing under different water-gas ratios according to a preset multiphase pipe flow model; and determining a corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical pressure coefficient curve of self-flowing. The application can realize efficient drainage gas production and production control.

Description

Technical Field

[0001] This application relates to the field of oil and gas extraction, specifically to a method and apparatus for determining the production mode of deep coalbed methane wells. Background Technology

[0002] Existing technologies exist in deep coalbed methane blocks with high gas saturation, high gas content, and rich free gas. Some wells can be produced by releasing gas through their own formation energy after fracturing, while others cannot flow naturally after fracturing and require artificial lifting, i.e., mechanical extraction. However, there is a lack of selection methods and judgment criteria for whether mechanically extracted wells can be converted to natural flow production, the selection of production methods for natural flow production wells (including tubing natural flow production, annular natural flow production, and bare casing natural flow production), and the timing of conversion to mechanical extraction production.

[0003] Currently, for wells that are capable of self-flowing after fracturing, the initial stage is either self-flowing production with bare casing or self-flowing production with pressurized tubing, until fluid accumulation prevents normal production, at which point mechanical production is switched to. There is currently no research on when to switch back to self-flowing production after mechanical production has started. Conventional oil and gas well shutdown prediction mainly uses formulas to calculate the bottomhole flowing pressure at shutdown; when the bottomhole flowing pressure reaches the shutdown pressure, mechanical production is switched to.

[0004] The existing technology has the following problems:

[0005] 1. The formation and occurrence of deep coalbed methane reservoirs are complex, involving both free and adsorbed gas. The changes in the water-to-gas ratio and bottom hole pressure over time during gas-water production differ significantly from those in conventional oil and gas wells, making it impossible to directly apply formulas.

[0006] 2. When calculating bottom hole pressure using multiphase pipe flow in conventional oil and gas wells, a single model is often used, without considering the impact of changes in flow regime caused by variations in the water-gas ratio in the wellbore on the calculation accuracy of each model, resulting in serious deviations in the calculation results.

[0007] 3. Conventional oil and gas well shutdown calculations are all for wells that start production and begin flowing. However, coalbed methane wells mainly produce adsorbed gas. Some wells need to undergo artificial lifting, drainage and depressurization to produce gas below the desorption pressure before they can switch to flowing production. There is currently no relevant technology for the timing and judgment of the switch. Summary of the Invention

[0008] To address at least one problem in the prior art, this application provides a method and apparatus for determining the production mode of deep coalbed methane wells, which can achieve efficient drainage and gas extraction as well as production control.

[0009] To solve at least one of the above problems, this application provides the following technical solution:

[0010] In a first aspect, this application provides a method for determining the production mode of deep coalbed methane wells, including:

[0011] Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, the water-gas ratio and bottom hole pressure at any production time are determined.

[0012] Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curves under different water-gas ratios, and determine the self-flowing critical pressure coefficient curves under different water-gas ratios based on the preset multiphase pipe flow model.

[0013] The corresponding deep coalbed methane well production method is determined based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0014] Further, determining the water-gas ratio at any production time based on the initial stable gas production water-gas ratio, the number of production days after the initial stable gas production, and a preset prediction model for the change in water-gas ratio and production days includes:

[0015] Based on the correspondence between the water-gas ratio at any production time and the number of production days after initial stable gas production and the water-gas ratio at the initial stable gas production, a prediction model for the change of water-gas ratio and number of production days is constructed.

[0016] The water-gas ratio for any production time is determined based on the water-gas ratio and production days variation prediction model.

[0017] Furthermore, the step of determining the bottom hole pressure at any production time based on the initial stable gas production bottom hole pressure, the number of production days after the initial stable gas production, and a preset prediction model for the change in bottom hole pressure and production days also includes:

[0018] Based on the correspondence between the bottom hole pressure at any production time and the number of production days after initial stable gas production and the bottom hole pressure at the time of initial stable gas production, a prediction model for the change of bottom hole pressure and production days is constructed.

[0019] Based on the wellbore pressure and production days variation prediction model, the wellbore pressure at any production time is determined.

[0020] Further, determining the production pressure coefficient curves for different water-gas ratios based on the water-gas ratio and bottom hole pressure at any given production time includes:

[0021] Based on the prediction models for the changes in water-gas ratio and production days corresponding to any production time and bottom-hole pressure, the calculation model for bottom-hole pressure and water-gas ratio is determined.

[0022] Based on the wellbore pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well, the production pressure coefficient curves under different water-gas ratios are determined.

[0023] Furthermore, determining the critical pressure coefficient curves for self-flowing jets under different water-to-air ratios based on a preset multiphase pipe flow model includes:

[0024] The corresponding multiphase pipe flow model is determined based on the prediction model of changes in water-air ratio and production days.

[0025] Based on the multiphase pipe flow model, nodal analysis was performed using the pressure of the external pipeline network as the wellhead pressure to determine the critical pressure coefficient curves for self-flowing under different water-gas ratios.

[0026] Further, determining the corresponding deep coalbed methane well production method based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve includes:

[0027] By superimposing the production pressure coefficient curve and the self-spraying critical pressure coefficient curve, a corresponding production mode conversion selection chart is obtained.

[0028] Based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production mode conversion selection diagram, the corresponding production mode is determined.

[0029] Secondly, this application provides a device for determining the production mode of a deep coalbed methane well, comprising:

[0030] The model prediction module is used to determine the water-gas ratio and bottom hole pressure at any production time based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days.

[0031] The curve determination module is used to determine the production pressure coefficient curve under different water-gas ratios based on the water-gas ratio and bottom hole pressure at any production time, and to determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on a preset multiphase pipe flow model.

[0032] The production mode determination module is used to determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0033] Furthermore, the model prediction module includes:

[0034] The water-gas ratio model construction unit is used to construct a prediction model for the change of water-gas ratio and production days based on the correspondence between the water-gas ratio at any production time and the number of production days after the initial stable gas production and the water-gas ratio at the initial stable gas production.

[0035] The water-gas ratio model prediction unit is used to determine the water-gas ratio for any production time based on the water-gas ratio and production days change prediction model.

[0036] Furthermore, the model prediction module also includes:

[0037] The bottom hole pressure model construction unit is used to construct a prediction model of the change in bottom hole pressure and production days based on the correspondence between the bottom hole pressure at any production time and the number of production days after initial stable gas production and the bottom hole pressure at the time of initial stable gas production.

[0038] The bottom hole pressure model prediction unit is used to determine the bottom hole pressure at any production time based on the bottom hole pressure and production days change prediction model.

[0039] Furthermore, the curve determination module includes:

[0040] The calculation model construction unit is used to determine the calculation model of bottom hole pressure and water-gas ratio based on the prediction model of water-gas ratio and production days change corresponding to the water-gas ratio and bottom hole pressure for any production time and the prediction model of bottom hole pressure and production days change.

[0041] The coefficient curve determination unit is used to determine the production pressure coefficient curve under different water-gas ratios based on the bottom hole pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well.

[0042] Furthermore, the curve determination module also includes:

[0043] The multiphase pipe flow model determination unit is used to determine the corresponding multiphase pipe flow model based on the prediction model of changes in water-air ratio and production days.

[0044] The node analysis unit is used to perform node analysis based on the pressure of the external pipeline network as the wellhead pressure in the multiphase pipe flow model, and to determine the critical pressure coefficient curve of the self-flowing flow under different water-gas ratios.

[0045] Furthermore, the production method determination module includes:

[0046] The curve overlay unit is used to overlay the production pressure coefficient curve and the self-spraying critical pressure coefficient curve to obtain the corresponding production mode conversion selection diagram.

[0047] The production method determination unit is used to determine the corresponding production method based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production method conversion selection drawing.

[0048] Thirdly, this application provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method for determining the production mode of a deep coalbed methane well.

[0049] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method for determining the production mode of a deep coalbed methane well.

[0050] Fifthly, this application provides a computer program product, including a computer program / instructions, which, when executed by a processor, implement the steps of the method for determining the production mode of a deep coalbed methane well.

[0051] As can be seen from the above technical solution, this application provides a method and apparatus for determining the production mode of deep coalbed methane wells. Through the method and selection chart for judging the conversion between self-flowing and mechanical production in deep coalbed methane wells, this application provides a basis for selecting the production mode of deep coalbed methane wells, thereby achieving efficient drainage and gas production control. It can significantly improve the stability and continuity of drainage production, achieve efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, and therefore has broad application prospects and significant economic benefits. Attached Figure Description

[0052] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] Figure 1 This is one of the flowcharts illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0054] Figure 2 This is the second flowchart illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0055] Figure 3 This is the third flowchart illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0056] Figure 4 This is the fourth flowchart illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0057] Figure 5 This is the fifth flowchart illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0058] Figure 6 This is the sixth flowchart illustrating the method for determining the production mode of deep coalbed methane wells in this application embodiment;

[0059] Figure 7This is one of the structural diagrams of the deep coalbed methane well production mode determination device in the embodiments of this application;

[0060] Figure 8 This is the second structural diagram of the device for determining the production mode of deep coalbed methane wells in the embodiments of this application;

[0061] Figure 9 This is the third structural diagram of the device for determining the production mode of deep coalbed methane wells in the embodiments of this application;

[0062] Figure 10 This is the fourth structural diagram of the deep coalbed methane well production mode determination device in the embodiments of this application;

[0063] Figure 11 This is the fifth structural diagram of the deep coalbed methane well production mode determination device in the embodiments of this application;

[0064] Figure 12 This is the sixth structural diagram of the deep coalbed methane well production mode determination device in the embodiments of this application;

[0065] Figure 13 This is a schematic diagram of linear regression in a specific embodiment of this application;

[0066] Figure 14 This is a schematic diagram of the fitting of water-air ratio and production days in a specific embodiment of this application;

[0067] Figure 15 This is a schematic diagram of the fitting of bottom hole pressure and production days in a specific embodiment of this application;

[0068] Figure 16 This is a schematic diagram of the fitting of bottom hole pressure and water-gas ratio in a specific embodiment of this application;

[0069] Figure 17 This is a schematic diagram of the selection of a self-flowing well production method in a specific embodiment of this application;

[0070] Figure 18 This is a schematic diagram of a production selection chart for converting a mechanically operated well to a self-flowing well, according to a specific embodiment of this application.

[0071] Figure 19 This is a schematic diagram of the structure of the electronic device in the embodiments of this application. Detailed Implementation

[0072] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0073] The acquisition, storage, use, and processing of data in this application all comply with the relevant provisions of national laws and regulations.

[0074] In view of the problems existing in the prior art, this application provides a method and apparatus for determining the production mode of deep coalbed methane wells. Through the method and selection chart for judging the conversion between self-flowing and mechanical production in deep coalbed methane wells, this application provides a basis for selecting the production mode of deep coalbed methane wells, thereby achieving efficient drainage and gas production control. It can significantly improve the stability and continuity of drainage production, achieve efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, and therefore has broad application prospects and significant economic benefits.

[0075] To achieve efficient drainage and gas extraction and production control, this application provides an embodiment of a method for determining the production mode of deep coalbed methane wells, see [link to embodiment]. Figure 1 The method for determining the production mode of deep coalbed methane wells specifically includes the following:

[0076] Step S101: Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, determine the water-gas ratio and bottom hole pressure at any production time.

[0077] In this embodiment, the water-to-gas ratio at the initial stable gas production stage is r0, and the water-to-gas ratio at any production time is r. i r i The difference between 1 / Δr and r0 is Δr, and the number of production days after the initial stable gas production is calculated as t. A graph showing the relationship between 1 / Δr and 1 / t is plotted, and a linear regression is performed to obtain the slope as follows: Intercept with the vertical axis is Where Δr max For the maximum value of Δr, t 0.5r Δr = 0.5Δr max The number of production days per hour. The prediction model for the change in water-to-air ratio and the number of production days is as follows:

[0078] In this embodiment, the bottom hole pressure at the initial stable gas production stage is p0, and the bottom hole pressure at any production time is p. i p iThe difference between p0 and p0 is Δp, and the number of production days after the initial stable gas production is calculated as t. A graph showing the relationship between 1 / Δp and 1 / t is plotted, and a linear regression is performed to obtain the slope as follows: Intercept with the vertical axis is Where Δp max For the maximum value of Δp, t 0.5p Δp = 0.5Δp max The prediction model for the change in production days, bottom hole pressure, and production days is as follows:

[0079] Step S102: Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curve under different water-gas ratios, and determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on the preset multiphase pipe flow model.

[0080] In this embodiment, the bottom hole pressure p is taken. i With the vertical depth hydrostatic pressure p of the gas well H The ratio is the production pressure coefficient αp i Plot the production pressure coefficient curves under different water-to-air ratios.

[0081] Well bottom pressure and water-gas ratio calculation model:

[0082] Production pressure coefficient calculation model:

[0083] In this embodiment, a multiphase pipe flow model is selected based on the water-gas ratio, and the pressure of the external transmission pipeline is used as the wellhead pressure. The critical bottom hole pressure and critical pressure coefficient αp are calculated through node analysis under different self-flowing production methods, gas production rates, and water-gas ratios. c Plot the critical pressure coefficient curves of the self-spraying system under different water-to-air ratios.

[0084] The method for selecting the multiphase pipe flow model is as follows: r i For values ​​≥12, the Gray model is used; for values ​​12 > r, the Gray model is used. i ≥5, use the Hagedorn-Brown model, r i <5. The Duns-Ros model is selected.

[0085] Step S103: Determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0086] In this embodiment, by overlaying the production pressure coefficient curve and the critical pressure coefficient curve plotted from production data onto a single graph, a selection chart for the conversion between self-flowing and machine-harvested production methods can be obtained. In the chart, the production pressure coefficient is higher than the critical pressure coefficient (αp). i >αp c If the production pressure coefficient is lower than the critical pressure coefficient (αp), then self-spraying production can be adopted.i ≤αp c If the process involves mechanical harvesting, then mechanical harvesting must be used.

[0087] As described above, the method for determining the production mode of deep coalbed methane wells provided in this application can provide a basis for selecting the production mode of deep coalbed methane wells by using the method and selection chart for judging the conversion between self-flowing and mechanical production. This enables efficient drainage and gas production control, significantly improves the stability and continuity of drainage production, achieves efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, and therefore has broad application prospects and significant economic benefits.

[0088] In one embodiment of the method for determining the production mode of deep coalbed methane wells in this application, see [reference needed]. Figure 2 It can also specifically include the following:

[0089] Step S201: Based on the correspondence between the water-gas ratio at any production time and the number of production days after initial stable gas production and the water-gas ratio at the initial stable gas production, construct a prediction model for the change in water-gas ratio and the number of production days.

[0090] Step S202: Determine the water-gas ratio for any production time according to the water-gas ratio and production days change prediction model.

[0091] In this embodiment, the water-to-gas ratio at the initial stable gas production stage is r0, and the water-to-gas ratio at any production time is r. i r i The difference between 1 / Δr and r0 is Δr, and the number of production days after the initial stable gas production is calculated as t. A graph showing the relationship between 1 / Δr and 1 / t is plotted, and a linear regression is performed to obtain the slope as follows: Intercept with the vertical axis is Where Δr max For the maximum value of Δr, t 0.5r Δr = 0.5Δr max The number of production days per hour. The prediction model for the change in water-to-air ratio and the number of production days is as follows:

[0092] In one embodiment of the method for determining the production mode of deep coalbed methane wells in this application, see [reference needed]. Figure 3 It can also specifically include the following:

[0093] Step S301: Based on the correspondence between the bottom hole pressure at any production time and the number of production days after initial stable gas production and the bottom hole pressure at the time of initial stable gas production, construct a prediction model for the change of bottom hole pressure and the number of production days.

[0094] Step S302: Determine the bottom hole pressure at any production time based on the predicted model of changes in bottom hole pressure and production days.

[0095] In this embodiment, the bottom hole pressure at the initial stable gas production stage is p0, and the bottom hole pressure at any production time is p. i p i The difference between p0 and p0 is Δp, and the number of production days after the initial stable gas production is calculated as t. A graph showing the relationship between 1 / Δp and 1 / t is plotted, and a linear regression is performed to obtain the slope as follows: Intercept with the vertical axis is Where Δp max For the maximum value of Δp, t 0.5p Δp = 0.5Δp max The prediction model for the change in production days, bottom hole pressure, and production days is as follows:

[0096] In one embodiment of the method for determining the production mode of deep coalbed methane wells in this application, see [reference needed]. Figure 4 It can also specifically include the following:

[0097] Step S401: Determine the calculation model for bottom hole pressure and water-gas ratio based on the prediction models for changes in water-gas ratio and production days corresponding to any production time and bottom hole pressure.

[0098] Step S402: Based on the bottom hole pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well, determine the production pressure coefficient curves under different water-gas ratios.

[0099] In this embodiment, the bottom hole pressure p is taken. i With the vertical depth hydrostatic pressure p of the gas well H The ratio is the production pressure coefficient αp i Plot the production pressure coefficient curves under different water-to-air ratios.

[0100] Well bottom pressure and water-gas ratio calculation model:

[0101] Production pressure coefficient calculation model:

[0102] In one embodiment of the method for determining the production mode of deep coalbed methane wells in this application, see [reference needed]. Figure 5 It can also specifically include the following:

[0103] Step S501: Determine the corresponding multiphase pipe flow model based on the prediction model of water-air ratio and production days variation;

[0104] Step S502: Based on the multiphase pipe flow model, perform node analysis using the pressure of the external pipeline network as the wellhead pressure to determine the critical pressure coefficient curve of the self-flowing flow under different water-gas ratios.

[0105] In this embodiment, a multiphase pipe flow model is selected based on the water-gas ratio, and the pressure of the external transmission pipeline is used as the wellhead pressure. The critical bottom hole pressure and critical pressure coefficient αp are calculated through node analysis under different self-flowing production methods, gas production rates, and water-gas ratios. c Plot the critical pressure coefficient curves of the self-spraying system under different water-to-air ratios.

[0106] The method for selecting the multiphase pipe flow model is as follows: r i For values ​​≥12, the Gray model is used; for values ​​12 > r, the Gray model is used. i ≥5, use the Hagedorn-Brown model, r i <5. The Duns-Ros model is selected.

[0107] In one embodiment of the method for determining the production mode of deep coalbed methane wells in this application, see [reference needed]. Figure 6 It can also specifically include the following:

[0108] Step S601: Overlay the production pressure coefficient curve and the self-spraying critical pressure coefficient curve to obtain the corresponding production mode conversion selection chart;

[0109] Step S602: Determine the corresponding production method based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production method conversion selection diagram.

[0110] In this embodiment, by overlaying the production pressure coefficient curve and the critical pressure coefficient curve plotted from production data onto a single graph, a selection chart for the conversion between self-flowing and machine-harvested production methods can be obtained. In the chart, the production pressure coefficient is higher than the critical pressure coefficient (αp). i >αp c If the production pressure coefficient is lower than the critical pressure coefficient (αp), then self-spraying production can be adopted. i ≤αp c If the process involves mechanical harvesting, then mechanical harvesting must be used.

[0111] To achieve efficient drainage and gas extraction and production control, this application provides an embodiment of a deep coalbed methane well production mode determination device for implementing all or part of the aforementioned deep coalbed methane well production mode determination method. See [link to embodiment]. Figure 7 The device for determining the production mode of deep coalbed methane wells specifically includes the following components:

[0112] The model prediction module 10 is used to determine the water-gas ratio and bottom hole pressure at any production time based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days.

[0113] The curve determination module 20 is used to determine the production pressure coefficient curve under different water-gas ratios based on the water-gas ratio and bottom hole pressure at any production time, and to determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on a preset multiphase pipe flow model.

[0114] The production mode determination module 30 is used to determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0115] As described above, the deep coalbed methane well production mode determination device provided in this application can provide a basis for selecting the production mode of deep coalbed methane wells by using the method and selection chart for judging the conversion between self-flowing and mechanical production in this application. This enables efficient drainage and gas production control, significantly improves the stability and continuity of drainage production, achieves efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, and therefore has broad application prospects and significant economic benefits.

[0116] In one embodiment of the deep coalbed methane well production mode determination device of this application, see [reference needed]. Figure 8 The model prediction module 10 includes:

[0117] The water-gas ratio model construction unit 11 is used to construct a prediction model of the change in water-gas ratio and production days based on the correspondence between the water-gas ratio at any production time and the number of production days after the initial stable gas production and the water-gas ratio at the initial stable gas production.

[0118] The water-gas ratio model prediction unit 12 is used to determine the water-gas ratio for any production time based on the water-gas ratio and production days change prediction model.

[0119] In one embodiment of the deep coalbed methane well production mode determination device of this application, see [reference needed]. Figure 9 The model prediction module 10 further includes:

[0120] Bottom hole pressure model building unit 13 is used to build a prediction model of changes in bottom hole pressure and production days based on the correspondence between bottom hole pressure at any production time and the number of production days after initial stable gas production and bottom hole pressure at initial stable gas production.

[0121] Bottom hole pressure model prediction unit 14 is used to determine the bottom hole pressure at any production time based on the bottom hole pressure and production days change prediction model.

[0122] In one embodiment of the deep coalbed methane well production mode determination device of this application, see [reference needed]. Figure 10 The curve determination module 20 includes:

[0123] The calculation model construction unit 21 is used to determine the calculation model of bottom hole pressure and water-gas ratio based on the prediction model of water-gas ratio and production days change corresponding to the water-gas ratio and bottom hole pressure for any production time and the prediction model of bottom hole pressure and production days change.

[0124] The coefficient curve determination unit 22 is used to determine the production pressure coefficient curve under different water-gas ratios based on the bottom hole pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well.

[0125] In one embodiment of the deep coalbed methane well production mode determination device of this application, see [reference needed]. Figure 11 The curve determination module 20 further includes:

[0126] Multiphase pipe flow model determination unit 23 is used to determine the corresponding multiphase pipe flow model based on the prediction model of water-air ratio and production days change;

[0127] The node analysis unit 24 is used to perform node analysis based on the pressure of the external pipeline network as the wellhead pressure in the multiphase pipe flow model, and to determine the critical pressure coefficient curve of the self-flowing flow under different water-gas ratios.

[0128] In one embodiment of the deep coalbed methane well production mode determination device of this application, see [reference needed]. Figure 12 The production method determination module 30 includes:

[0129] Curve overlay unit 31 is used to overlay the production pressure coefficient curve and the self-spraying critical pressure coefficient curve to obtain the corresponding production mode conversion selection chart.

[0130] The production method determination unit 32 is used to determine the corresponding production method based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production method conversion selection diagram.

[0131] To further illustrate this solution, this application also provides a specific application example of using the aforementioned deep coalbed methane well production mode determination device to realize the method for determining the production mode of deep coalbed methane wells, which specifically includes the following:

[0132] 1. Establish a predictive model for changes in water-gas ratio, bottom hole pressure, and production days.

[0133] The initial stable gas production has a water-to-gas ratio of r0, and the water-to-gas ratio at any production time is r. i r i The difference between r0 and r0 is Δr, and the number of production days after the initial stable gas production is calculated as t.

[0134] See Figure 13 and Figure 14 Plot the relationship between 1 / Δr and 1 / t and perform linear regression to obtain the slope as follows: Intercept with the vertical axis is Where Δr max For the maximum value of Δr, t 0.5r Δr = 0.5Δr max The number of production days per hour. The prediction model for the change in water-to-air ratio and the number of production days is as follows:

[0135] See Figure 13 and Figure 15 The initial stable gas production at the bottom of the well is p0, and the bottom of the well at any production time is p. i p i The difference between p0 and p0 is Δp, and the number of production days after the initial stable gas production is calculated as t. A graph showing the relationship between 1 / Δp and 1 / t is plotted, and a linear regression is performed to obtain the slope as follows: Intercept with the vertical axis is Where Δp max For the maximum value of Δp, t 0.5p Δp = 0.5Δp max The prediction model for the change in production days, bottom hole pressure, and production days is as follows:

[0136] 2. Establish a calculation model for bottom hole pressure and water-gas ratio.

[0137] See Figure 16 Take the bottom pressure p i With the vertical depth hydrostatic pressure p of the gas well H The ratio is the production pressure coefficient αp i Plot the production pressure coefficient curves under different water-to-air ratios.

[0138] Well bottom pressure and water-gas ratio calculation model:

[0139] Production pressure coefficient calculation model:

[0140] 3. Based on the water-gas ratio, a multiphase pipe flow model is selected, and the pressure of the external transmission pipeline is used as the wellhead pressure. Through nodal analysis, the critical bottom hole pressure and critical pressure coefficient αp are calculated under different self-flowing production methods, gas production rates, and water-gas ratios. c Plot the critical pressure coefficient curves of the self-spraying system under different water-to-air ratios.

[0141] The method for selecting the multiphase pipe flow model is as follows: r i For values ​​≥12, the Gray model is used; for values ​​12 > r, the Gray model is used. i ≥5, use the Hagedorn-Brown model, r i <5. The Duns-Ros model is selected.

[0142] 4. By overlaying the production pressure coefficient curve and the critical pressure coefficient curve plotted from the production data onto a single graph, a selection chart for the conversion between self-flowing and machine-harvested production methods can be obtained. In this chart, the production pressure coefficient is higher than the critical pressure coefficient (αp). i >αp c If the production pressure coefficient is lower than the critical pressure coefficient (αp), then self-spraying production can be adopted. i ≤αp c If the process involves mechanical harvesting, then mechanical harvesting must be used.

[0143] For details, see Figure 17 Because the production pressure coefficient curve is higher than the critical pressure curves for self-flowing in the annulus and the bare casing, but lower than the critical pressure curve for self-flowing in the tubing, self-flowing production in the annulus is possible, but self-flowing production in the tubing is not. When the water-air ratio is lower than point A, the intersection of the production pressure coefficient curve and the critical pressure curve for self-flowing in the annulus, self-flowing production in the annulus will not be possible, and it will need to be switched to self-flowing production in the bare casing. When the water-air ratio is lower than point B, the intersection of the production pressure coefficient curve and the critical pressure curve for self-flowing in the bare casing, self-flowing production will not be possible, and it will need to be switched to mechanical pumping.

[0144] See Figure 18 Since the production pressure coefficient curve of the mechanically pumped well was lower than the critical pressure coefficient curve for self-flowing oil in the early stage, artificial lift production was adopted. As the gas production increased due to depressurization and the water-gas ratio decreased, when the water-gas ratio fell below point A in the figure, the production pressure coefficient curve was higher than the critical pressure coefficient curve for self-flowing oil in the 88.9mm tubing, and mechanical pumping production switched to self-flowing production. When the water-gas ratio fell below point B, self-flowing production switched back to mechanical pumping production. As shown in the figure, when using 73mm or 60.3mm tubing, the production pressure coefficient curves in the early and middle stages were higher than the critical pressure coefficient curve for self-flowing oil, i.e., self-flowing production was maintained. Therefore, selecting an appropriate tubing according to the figure can significantly extend the self-flowing production time.

[0145] As can be seen from the above, the application of this invention in the field can significantly improve the stability and continuity of fluid drainage production, achieve efficient fluid drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, and therefore has broad application prospects and significant economic benefits.

[0146] From a hardware perspective, in order to achieve efficient drainage and gas extraction and production control, this application provides an embodiment of an electronic device for implementing all or part of the deep coalbed methane well production mode determination method, wherein the electronic device specifically includes the following:

[0147] The system comprises a processor, memory, a communications interface, and a bus; wherein the processor, memory, and communications interface communicate with each other via the bus; the communications interface is used to realize information transmission between the deep coalbed methane well production mode determination device and core business systems, user terminals, and related databases and other related equipment; the logic controller can be a desktop computer, tablet computer, or mobile terminal, etc., and this embodiment is not limited to these. In this embodiment, the logic controller can be implemented with reference to the embodiments of the deep coalbed methane well production mode determination method and the deep coalbed methane well production mode determination device in the embodiments, the contents of which are incorporated herein, and repeated details will not be repeated.

[0148] It is understood that the user terminal may include smartphones, tablet computers, network set-top boxes, portable computers, desktop computers, personal digital assistants (PDAs), in-vehicle devices, smart wearable devices, etc. Among these, the smart wearable devices may include smart glasses, smartwatches, smart bracelets, etc.

[0149] In practical applications, the method for determining the production mode of deep coalbed methane wells can be partially executed on the electronic device side as described above, or all operations can be completed in the client device. The choice can be made based on the processing power of the client device and the limitations of the user's usage scenario. This application does not impose any limitations on this. If all operations are completed in the client device, the client device may further include a processor.

[0150] The aforementioned client device may have a communication module (i.e., a communication unit) that can communicate with a remote server to achieve data transmission. The server may include a server on the task scheduling center side; in other implementation scenarios, it may also include a server on an intermediate platform, such as a server on a third-party server platform that has a communication link with the task scheduling center server. The server may include a single computer device, a server cluster consisting of multiple servers, or a distributed server structure.

[0151] Figure 19 This is a schematic block diagram illustrating the system configuration of the electronic device 9600 according to an embodiment of this application. Figure 19 As shown, the electronic device 9600 may include a central processing unit 9100 and a memory 9140; the memory 9140 is coupled to the central processing unit 9100. It is worth noting that... Figure 19 This is an example; other types of structures can also be used to supplement or replace this structure to achieve telecommunications functions or other functions.

[0152] In one embodiment, the function of determining the production mode of a deep coalbed methane well can be integrated into a central processing unit 9100. The central processing unit 9100 can be configured to perform the following control:

[0153] Step S101: Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, determine the water-gas ratio and bottom hole pressure at any production time.

[0154] Step S102: Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curve under different water-gas ratios, and determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on the preset multiphase pipe flow model.

[0155] Step S103: Determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0156] As described above, the electronic equipment provided in this application, through the method and selection chart for determining the conversion between self-flowing and mechanical production in deep coalbed methane wells, provides a basis for selecting the production mode of deep coalbed methane wells. This enables efficient drainage and gas production control, significantly improving the stability and continuity of drainage production, achieving efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, thus having broad application prospects and significant economic benefits.

[0157] In another embodiment, the deep coalbed methane well production mode determination device can be configured separately from the central processing unit 9100. For example, the deep coalbed methane well production mode determination device can be configured as a chip connected to the central processing unit 9100, and the deep coalbed methane well production mode determination method function can be realized through the control of the central processing unit.

[0158] like Figure 19 As shown, the electronic device 9600 may further include: a communication module 9110, an input unit 9120, an audio processor 9130, a display 9160, and a power supply 9170. It is worth noting that the electronic device 9600 does not necessarily need to include these components. Figure 19 All components shown; in addition, the electronic device 9600 may also include Figure 19 For components not shown, please refer to existing technologies.

[0159] like Figure 19 As shown, the central processing unit 9100, sometimes also referred to as a controller or operating control, may include a microprocessor or other processor device and / or logic device, which receives inputs and controls the operation of various components of the electronic device 9600.

[0160] The memory 9140 may be, for example, one or more of a cache, flash memory, hard drive, removable media, volatile memory, non-volatile memory, or other suitable devices. It may store the aforementioned failure-related information, and also store a program for executing that information. The central processing unit 9100 may execute the program stored in the memory 9140 to perform information storage or processing, etc.

[0161] Input unit 9120 provides input to central processing unit 9100. Input unit 9120 may be, for example, a keypad or touch input device. Power supply 9170 provides power to electronic device 9600. Display 9160 displays images and text. Display may be, for example, an LCD display, but is not limited thereto.

[0162] The memory 9140 can be a solid-state memory, such as a read-only memory (ROM), random access memory (RAM), a SIM card, etc. It can also be a memory that retains information even when power is off, can be selectively erased, and contains more data; examples of this type of memory are sometimes referred to as EPROMs. The memory 9140 can also be some other type of device. The memory 9140 includes a buffer memory 9141 (sometimes referred to as a buffer). The memory 9140 may include an application / function storage unit 9142 for storing application programs and function programs or processes for executing the operation of the electronic device 9600 via the central processing unit 9100.

[0163] The memory 9140 may also include a data storage unit 9143 for storing data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage unit 9144 of the memory 9140 may include various drivers for the electronic device's communication functions and / or for performing other functions of the electronic device (such as messaging applications, address book applications, etc.).

[0164] The communication module 9110 is a transmitter / receiver 9110 that transmits and receives signals via the antenna 9111. The communication module (transmitter / receiver) 9110 is coupled to the central processing unit 9100 to provide input signals and receive output signals, which can be the same as in a conventional mobile communication terminal.

[0165] Based on different communication technologies, multiple communication modules 9110 can be configured in the same electronic device, such as cellular network modules, Bluetooth modules, and / or wireless LAN modules. The communication module (transmitter / receiver) 9110 is also coupled to a speaker 9131 and a microphone 9132 via an audio processor 9130 to provide audio output via the speaker 9131 and receive audio input from the microphone 9132, thereby realizing typical telecommunications functions. The audio processor 9130 may include any suitable buffer, decoder, amplifier, etc. Additionally, the audio processor 9130 is coupled to a central processing unit 9100, enabling on-device recording via the microphone 9132 and on-device playback of stored sound via the speaker 9131.

[0166] Embodiments of this application also provide a computer-readable storage medium capable of implementing all steps of the deep coalbed methane well production mode determination method with a server or client as the execution subject in the above embodiments. The computer-readable storage medium stores a computer program that, when executed by a processor, implements all steps of the deep coalbed methane well production mode determination method with a server or client as the execution subject in the above embodiments. For example, when the processor executes the computer program, it implements the following steps:

[0167] Step S101: Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, determine the water-gas ratio and bottom hole pressure at any production time.

[0168] Step S102: Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curve under different water-gas ratios, and determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on the preset multiphase pipe flow model.

[0169] Step S103: Determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0170] As described above, the computer-readable storage medium provided in this application, through the method and selection chart for determining the conversion between self-flowing and mechanical production in deep coalbed methane wells, provides a basis for selecting production methods for deep coalbed methane wells. This enables efficient drainage and gas production control, significantly improving the stability and continuity of drainage production, achieving efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, thus having broad application prospects and significant economic benefits.

[0171] Embodiments of this application also provide a computer program product capable of implementing all steps in the deep coalbed methane well production mode determination method described above, where the execution subject is a server or client. When executed by a processor, this computer program / instruction implements the steps of the deep coalbed methane well production mode determination method. For example, the computer program / instruction implements the following steps:

[0172] Step S101: Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, determine the water-gas ratio and bottom hole pressure at any production time.

[0173] Step S102: Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curve under different water-gas ratios, and determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on the preset multiphase pipe flow model.

[0174] Step S103: Determine the corresponding deep coalbed methane well production mode based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve.

[0175] As described above, the computer program product provided in this application, through its method for determining the conversion between self-flowing and mechanical production in deep coalbed methane wells and its selection chart, provides a basis for selecting production methods for deep coalbed methane wells. This enables efficient drainage and gas production control, significantly improving the stability and continuity of drainage production, achieving efficient drainage and a steady increase in gas production, thereby improving the recovery rate. This invention is widely applicable to deep coalbed methane wells, thus having broad application prospects and significant economic benefits.

[0176] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0177] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (devices), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0178] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0179] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0180] Specific embodiments have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this invention. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A method for determining the production mode of a deep coalbed methane well, characterized in that, The method includes: Based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days, the water-gas ratio and bottom hole pressure at any production time are determined. Based on the water-gas ratio and bottom hole pressure at any production time, determine the production pressure coefficient curves under different water-gas ratios, and determine the self-flowing critical pressure coefficient curves under different water-gas ratios based on the preset multiphase pipe flow model. The corresponding deep coalbed methane well production method is determined based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve. The step of determining the water-gas ratio at any production time based on the water-gas ratio at the initial stable gas production, the number of production days after the initial stable gas production, and a preset prediction model for the change in water-gas ratio and production days includes: Based on the correspondence between the water-gas ratio at any production time and the number of production days after initial stable gas production and the water-gas ratio at initial stable gas production, a prediction model for the change of water-gas ratio and number of production days is constructed. The water-gas ratio for any production time is determined based on the aforementioned prediction model for changes in water-gas ratio and production days. The step of determining the bottom hole pressure at any production time based on the bottom hole pressure at initial stable gas production, the number of production days after initial stable gas production, and a preset prediction model for changes in bottom hole pressure and production days further includes: Based on the correspondence between the bottom hole pressure at any production time and the number of production days after initial stable gas production and the bottom hole pressure at the time of initial stable gas production, a prediction model for the change of bottom hole pressure and production days is constructed. Based on the wellbore pressure and production days variation prediction model, the wellbore pressure at any production time is determined.

2. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, The step of determining the production pressure coefficient curves for different water-gas ratios based on the water-gas ratio and bottom-hole pressure at any given production time includes: Based on the prediction models for the changes in water-gas ratio and production days corresponding to any production time and bottom-hole pressure, the calculation model for bottom-hole pressure and water-gas ratio is determined. Based on the wellbore pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well, the production pressure coefficient curves under different water-gas ratios are determined.

3. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, The step of determining the critical pressure coefficient curves of the self-spraying system under different water-to-air ratios based on a preset multiphase pipe flow model includes: The corresponding multiphase pipe flow model is determined based on the prediction model of changes in water-air ratio and production days. Based on the multiphase pipe flow model, nodal analysis was performed using the pressure of the external pipeline network as the wellhead pressure to determine the critical pressure coefficient curves for self-flowing under different water-gas ratios.

4. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, The step of determining the corresponding deep coalbed methane well production method based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve includes: By superimposing the production pressure coefficient curve and the self-spraying critical pressure coefficient curve, a corresponding production mode conversion selection chart is obtained. Based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production mode conversion selection diagram, the corresponding production mode is determined.

5. A device for determining the production mode of a deep coalbed methane well, characterized in that, include: The model prediction module is used to determine the water-gas ratio and bottom hole pressure at any production time based on the water-gas ratio and bottom hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction models for changes in water-gas ratio and production days and changes in bottom hole pressure and production days. The curve determination module is used to determine the production pressure coefficient curve under different water-gas ratios based on the water-gas ratio and bottom hole pressure at any production time, and to determine the self-flowing critical pressure coefficient curve under different water-gas ratios based on a preset multiphase pipe flow model. The production method determination module is used to determine the corresponding deep coalbed methane well production method based on the production pressure coefficient curve and the self-flowing critical pressure coefficient curve. The model prediction module includes: The water-gas ratio model construction unit is used to construct a prediction model for the change of water-gas ratio and production days based on the correspondence between the water-gas ratio at any production time and the number of production days after the initial stable gas production and the water-gas ratio at the initial stable gas production. A water-gas ratio model prediction unit is used to determine the water-gas ratio for any production time based on the water-gas ratio and production days change prediction model. The model prediction module also includes: The bottom hole pressure model construction unit is used to construct a prediction model of the change in bottom hole pressure and production days based on the correspondence between the bottom hole pressure at any production time and the number of production days after initial stable gas production and the bottom hole pressure at the time of initial stable gas production. The bottom hole pressure model prediction unit is used to determine the bottom hole pressure at any production time based on the bottom hole pressure and production days change prediction model.

6. The apparatus for determining the production mode of a deep coalbed methane well according to claim 5, characterized in that, The curve determination module includes: The calculation model construction unit is used to determine the calculation model of bottom hole pressure and water-gas ratio based on the prediction model of water-gas ratio and production days change corresponding to the water-gas ratio and bottom hole pressure for any production time and the prediction model of bottom hole pressure and production days change. The coefficient curve determination unit is used to determine the production pressure coefficient curve under different water-gas ratios based on the bottom hole pressure and water-gas ratio calculation model and the preset vertical depth static water pressure of the gas well.

7. The apparatus for determining the production mode of a deep coalbed methane well according to claim 5, characterized in that, The curve determination module also includes: The multiphase pipe flow model determination unit is used to determine the corresponding multiphase pipe flow model based on the prediction model of changes in water-air ratio and production days. The node analysis unit is used to perform node analysis based on the pressure of the external pipeline network as the wellhead pressure in the multiphase pipe flow model, and to determine the critical pressure coefficient curve of the self-flowing flow under different water-gas ratios.

8. The apparatus for determining the production mode of a deep coalbed methane well according to claim 5, characterized in that, The production method determination module includes: The curve overlay unit is used to overlay the production pressure coefficient curve and the self-spraying critical pressure coefficient curve to obtain the corresponding production mode conversion selection diagram. The production method determination unit is used to determine the corresponding production method based on the curve height and intersection point of the production pressure coefficient curve and the self-spraying critical pressure coefficient curve in the production method conversion selection drawing.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the method for determining the production mode of deep coalbed methane wells as described in any one of claims 1 to 4.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method for determining the production mode of a deep coalbed methane well as described in any one of claims 1 to 4.

11. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the steps of the method for determining the production mode of a deep coalbed methane well as described in any one of claims 1 to 4.

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