Method and device for determining production mode of deep coal-bed gas well

Abstract

The embodiment of the invention provides a method and device for determining the production mode of a deep coal-bed gas well, and the method comprises the steps: obtaining the production mode of the deep coal-bed gas well according to the water-gas ratio and bottom hole pressure during initial stable gas production, the number of production days after initial stable gas production, a preset water-gas ratio and production day number change prediction model, and a bottom hole pressure and production day number change prediction model; the water-gas ratio and the bottom hole pressure at any production time are determined; according to the water-gas ratio and the bottom hole pressure at any production time, a production pressure coefficient curve under different water-gas ratios is determined, and a blowing critical pressure coefficient curve under different water-gas ratios is determined according to a preset multiphase pipe flow model; determining a corresponding deep coal-bed gas well production mode according to the production pressure coefficient curve and the blowing critical pressure coefficient curve; according to the invention, efficient drainage gas recovery and production management and control can be realized.

Description

Technical Field

[0001] This application relates to the field of oil and gas exploitation, and particularly to a method and device for determining the production mode of deep coalbed methane wells. Background Art

[0002] In the prior art, there are high gas saturation, high gas content and rich free gas in the deep coalbed methane of some blocks. After fracturing and reconstruction of some wells, they can rely on their own formation energy for blowout production. Some wells cannot flow naturally after fracturing and need to adopt artificial lift, that is, mechanical production. However, there is a lack of selection methods and judgment bases for whether the gas production well can be converted to natural flow production after mechanical production, the selection of natural flow production mode (including three modes: tubing natural flow production, casing-tubing annulus natural flow production, and open-hole casing natural flow production), and the timing of conversion to mechanical production.

[0003] Currently, for the wells that can flow naturally after fracturing and reconstruction, they first adopt open-hole casing natural flow production or tubing natural flow production with pressure, until the liquid accumulation cannot produce normally, then they are converted to mechanical production. There is no research on when to convert to natural flow production after mechanical production. The prediction of well shut-in in conventional oil and gas wells mainly uses formulas to calculate the bottom-hole flowing pressure at the time of well shut-in, and when the bottom-hole flowing pressure reaches the shut-in flowing pressure, it is changed to mechanical production.

[0004] The prior art has the following problems:

[0005] 1. The accumulation and occurrence of deep coalbed methane are complex, and there are both free gas and adsorbed gas. The changing trends of the water-gas ratio and bottom-hole pressure with time during gas and water production are very different from those of conventional oil and gas wells, and formulas cannot be directly copied or applied.

[0006] 2. When calculating the bottom-hole pressure using multiphase pipe flow in conventional oil and gas wells, a single model is mostly used, without considering the influence of the flow pattern change caused by the change of the water-gas ratio in the wellbore on the calculation accuracy of each model, resulting in serious deviation of the calculation results.

[0007] 3. The calculation objects of well shut-in in conventional oil and gas wells are all the wells that flow naturally from the start of production. However, coalbed methane wells are mainly adsorbed gas, and some wells need to first undergo artificial lift to drain water and reduce pressure to below the desorption pressure, and then a large amount of adsorbed gas can be produced before being converted to natural flow production. There is currently no related technology for the conversion timing and judgment method. Summary of the Invention

[0008] In view of at least one of the problems in the prior art, this application provides a method and device for determining the production mode of deep coalbed methane wells, which can achieve efficient drainage gas production and production control.

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

[0010] In the 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 the change of water-gas ratio with production days and the change of bottom-hole pressure with production days, determine the water-gas ratio and bottom-hole pressure at any production time;

[0012] Based on the water-gas ratio and bottom-hole pressure at any production time, determine the production pressure coefficient curve at different water-gas ratios, and determine the critical flowing pressure coefficient curve at different water-gas ratios according to the preset multiphase pipe flow model;

[0013] Determine the production mode of the deep coalbed methane well corresponding to the production pressure coefficient curve and the critical flowing pressure coefficient curve.

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

[0015] Construct a prediction model for the change of water-gas ratio with production days according to the corresponding relationship between the water-gas ratio at any production time, the number of production days after the initial stable gas production, and the water-gas ratio at the initial stable gas production;

[0016] Determine the water-gas ratio at any production time according to the prediction model for the change of water-gas ratio with production days.

[0017] Further, the determining of the bottom-hole pressure at any production time according to the bottom-hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction model for the change of bottom-hole pressure with production days further includes:

[0018] Construct a prediction model for the change of bottom-hole pressure with production days according to the corresponding relationship between the bottom-hole pressure at any production time, the number of production days after the initial stable gas production, and the bottom-hole pressure at the initial stable gas production;

[0019] Determine the bottom-hole pressure at any production time according to the prediction model for the change of bottom-hole pressure with production days.

[0020] Further, the determining of the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time includes:

[0021] Determine a calculation model for bottom-hole pressure and water-gas ratio according to the prediction models for the change of water-gas ratio with production days and the change of bottom-hole pressure with production days corresponding to the water-gas ratio and bottom-hole pressure at any production time;

[0022] Determine the production pressure coefficient curve at different water-gas ratios according to the calculation model for bottom-hole pressure and water-gas ratio and the static water pressure of the preset gas well vertical depth.

[0023] Further, determining the critical flowing pressure coefficient curve at different water - gas ratios according to the preset multiphase pipe flow model includes:

[0024] Determining the corresponding multiphase pipe flow model according to the water - gas ratio and production days change prediction model;

[0025] Performing nodal analysis with the external pipeline network pressure as the wellhead pressure according to the multiphase pipe flow model to determine the critical flowing pressure coefficient curve at different water - gas ratios.

[0026] Further, determining the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical flowing pressure coefficient curve includes:

[0027] Superposing the production pressure coefficient curve and the critical flowing pressure coefficient curve to obtain the corresponding production mode conversion selection chart;

[0028] Determining the corresponding production mode according to the curve height and curve intersection point of the production pressure coefficient curve and the critical flowing pressure coefficient curve in the production mode conversion selection chart.

[0029] In a second aspect, the present application provides a device for determining the production mode of a deep coalbed methane well, including:

[0030] A model prediction module, configured to determine the water - gas ratio and bottom - hole pressure at any production time according to the water - gas ratio and bottom - hole pressure at the initial stable gas production, the production days after the initial stable gas production, and the preset water - gas ratio and production days change prediction model and bottom - hole pressure and production days change prediction model;

[0031] A curve determination module, configured to determine the production pressure coefficient curve at different water - gas ratios according to the water - gas ratio and bottom - hole pressure at any production time, and determine the critical flowing pressure coefficient curve at different water - gas ratios according to the preset multiphase pipe flow model;

[0032] A production mode determination module, configured to determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical flowing pressure coefficient curve.

[0033] Further, the model prediction module includes:

[0034] A water - gas ratio model construction unit, configured to construct a water - gas ratio and production days change prediction model according to the corresponding relationship between the water - gas ratio at any production time, the production days after the initial stable gas production, and the water - gas ratio at the initial stable gas production;

[0035] A water - gas ratio model prediction unit, configured to determine the water - gas ratio at any production time according to the water - gas ratio and production days change prediction model.

[0036] Further, the model prediction module further includes:

[0037] A bottom hole pressure model construction unit, configured to construct a prediction model for the change of bottom hole pressure with production days according to the corresponding relationship between the bottom hole pressure at any production time, the number of production days after initial stable gas production, and the bottom hole pressure at the time of initial stable gas production;

[0038] A bottom hole pressure model prediction unit, configured to determine the bottom hole pressure at any production time according to the prediction model for the change of bottom hole pressure with production days.

[0039] Further, the curve determination module includes:

[0040] A calculation model construction unit, configured to determine a calculation model for bottom hole pressure and water-gas ratio according to the prediction model for the change of water-gas ratio with production days and the prediction model for the change of bottom hole pressure with production days corresponding to the water-gas ratio and bottom hole pressure at any production time;

[0041] A coefficient curve determination unit, configured to determine a production pressure coefficient curve at different water-gas ratios according to the calculation model for bottom hole pressure and water-gas ratio and the preset hydrostatic pressure of the gas well vertical depth.

[0042] Further, the curve determination module further includes:

[0043] A multiphase pipe flow model determination unit, configured to determine a corresponding multiphase pipe flow model according to the prediction model for the change of water-gas ratio with production days;

[0044] A node analysis unit, configured to perform node analysis with the external transmission network pressure as the wellhead pressure according to the multiphase pipe flow model, and determine a self-flowing critical pressure coefficient curve at different water-gas ratios.

[0045] Further, the production mode determination module includes:

[0046] A curve superposition unit, configured to superpose the production pressure coefficient curve and the self-flowing critical pressure coefficient curve to obtain a corresponding production mode conversion selection chart;

[0047] A production mode determination unit, configured to determine the corresponding production mode according to the curve height and curve intersection point of the production pressure coefficient curve and the self-flowing critical pressure coefficient curve in the production mode conversion selection chart.

[0048] In a third aspect, the present application provides an electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, where when the processor executes the program, the steps of the method for determining the production mode of a deep coalbed methane well are implemented.

[0049] Fourthly, the present application provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for determining the production mode of a deep coalbed methane well are implemented.

[0050] Fifthly, the present application provides a computer program product, including a computer program / instructions. When the computer program / instructions are executed by a processor, the steps of the method for determining the production mode of a deep coalbed methane well are implemented.

[0051] As can be seen from the above technical solutions, the present application provides a method and device for determining the production mode of a deep coalbed methane well. Through the method and selection chart for judging the conversion between natural flow and mechanical production of deep coalbed methane wells in the present application, a basis is provided for the selection of the production mode of deep coalbed methane wells, so as to achieve efficient drainage gas production and production control, significantly improve the stability and continuity of liquid drainage production, realize efficient liquid drainage and a steady increase in gas production, and thus improve the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0053] Figure 1 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0054] Figure 2 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0055] Figure 3 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0056] Figure 4 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0057] Figure 5 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0058] Figure 6 One of the schematic flowcharts of the method for determining the production mode of a deep coalbed methane well in an embodiment of the present application;

[0059] Figure 7One of the structural diagrams of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0060] Figure 8 Another structural diagram of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0061] Figure 9 Another structural diagram of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0062] Figure 10 Another structural diagram of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0063] Figure 11 Another structural diagram of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0064] Figure 12 Another structural diagram of the deep coalbed methane well production mode determination device in the embodiments of the present application;

[0065] Figure 13 Schematic diagram of linear regression in a specific embodiment of the present application;

[0066] Figure 14 Schematic diagram of the fitting of water-gas ratio and production days in a specific embodiment of the present application;

[0067] Figure 15 Schematic diagram of the fitting of bottom hole pressure and production days in a specific embodiment of the present application;

[0068] Figure 16 Schematic diagram of the fitting of bottom hole pressure and water-gas ratio in a specific embodiment of the present application;

[0069] Figure 17 Schematic diagram of the production mode selection chart for flowing wells in a specific embodiment of the present application;

[0070] Figure 18 Schematic diagram of the production mode selection chart for the conversion of rod pumped wells to flowing wells in a specific embodiment of the present application;

[0071] Figure 19 Schematic diagram of the structure of the electronic device in the embodiments of the present application. Detailed implementation manners

[0072] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0073] In the technical solutions of this application, the acquisition, storage, use, processing, etc. of data all comply with the relevant provisions of national laws and regulations.

[0074] Considering the problems existing in the prior art, this application provides a method and device for determining the production mode of deep coalbed methane wells. Through the self-flowing and mechanical production conversion judgment method and selection chart for deep coalbed methane wells in this application, it provides a basis for the selection of the production mode of deep coalbed methane wells, thereby realizing efficient drainage gas production and production control, significantly improving the stability and continuity of liquid drainage production, achieving efficient liquid drainage and a steady increase in gas production, and thus improving the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

[0075] In order to be able to achieve efficient drainage gas production and production control, this application provides an embodiment of a method for determining the production mode of deep coalbed methane wells. Refer to Figure 1 , the method for determining the production mode of the deep coalbed methane well specifically includes the following content:

[0076] Step S101: According to 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 water-gas ratio and production days change prediction model and bottom-hole pressure and production days change prediction model, determine the water-gas ratio and bottom-hole pressure at any production time;

[0077] In this embodiment, the water-gas ratio at the initial stable gas production is r 0 , the water-gas ratio at any production time is r i , r i The difference from r 0 is Δr, and the number of production days calculated from after the initial stable gas production is t. Make a graph of 1 / Δr versus 1 / t and perform linear regression fitting to obtain a slope of and a vertical-axis intercept of where Δr max is the maximum value of Δr, and t 0.5r is the number of production days when Δr = 0.5Δr max . The water-gas ratio and production days change prediction model is:

[0078] In this embodiment, the bottom-hole pressure at the initial stable gas production is p 0, the bottom-hole pressure at any production time is p i , p i The difference from p 0 is Δp, and the number of production days t is calculated from the initial stable gas production. Plot the relationship between 1 / Δp and 1 / t and perform linear regression fitting to obtain a slope of and a vertical-axis intercept of where Δp max is the maximum value of Δp, and t 0.5p is the number of production days when Δp = 0.5Δp max . The prediction model for the change of bottom-hole pressure and production days is

[0079] Step S102: Determine the production pressure coefficient curves at different gas-water ratios according to the gas-water ratio and the bottom-hole pressure at any production time, and determine the flowing critical pressure coefficient curves at different gas-water ratios according to the preset multiphase pipe flow model;

[0080] In this embodiment, take the ratio of the bottom-hole pressure p i to the hydrostatic pressure p H of the vertical depth of the gas well as the production pressure coefficient αp i , and plot the production pressure coefficient curves at different gas-water ratios.

[0081] Bottom-hole pressure and gas-water ratio calculation model:

[0082] Production pressure coefficient calculation model:

[0083] In this embodiment, select the multiphase pipe flow model according to the gas-water ratio. Take the external transmission pipeline network pressure as the wellhead pressure, and calculate the critical bottom-hole pressure and the critical pressure coefficient αp c at different flowing production modes, gas production rates and gas-water ratios through nodal analysis, and plot the flowing critical pressure coefficient curves at different gas-water ratios.

[0084] The method for selecting the multiphase pipe flow model is: r i ≥12 selects the Gray model, 12 > r i ≥5 selects the Hagedorn-Brown model, r i <5 selects the Duns-Ros model.

[0085] Step S103: Determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the flowing critical pressure coefficient curve.

[0086] In this embodiment, overlay the production pressure coefficient curve and the critical pressure coefficient curve plotted from the production data on one graph to obtain the conversion selection chart for the flowing and mechanical production modes. In the graph, the production pressure coefficient is higher than the critical pressure coefficient (αpi >αp c ),if it is greater than the critical pressure coefficient (αp i ≤αp c ), then artificial lift production is required.

[0087] As can be seen from the above description, the method for determining the production mode of deep coalbed methane wells provided by the embodiments of the present application can provide a basis for selecting the production mode of deep coalbed methane wells through the method for judging the conversion between natural flow and artificial lift production and the selection chart for deep coalbed methane wells in the present application, so as to achieve efficient drainage gas production and production control, significantly improve the stability and continuity of liquid drainage production, realize efficient liquid drainage and a steady increase in gas production, and thus improve the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

[0088] In an embodiment of the method for determining the production mode of deep coalbed methane wells of the present application, referring to Figure 2 , it may specifically include the following content:

[0089] Step S201: Construct a prediction model for the change of water-gas ratio with production days according to the corresponding relationship between the water-gas ratio at any production time, the production days after initial stable gas production, and the water-gas ratio at the time of initial stable gas production;

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

[0091] In this embodiment, the water-gas ratio at the time of initial stable gas production is r 0 , the water-gas ratio at any production time is r i , the difference between r i and r 0 is Δr, and the production days are calculated as t after initial stable gas production. Make a graph of 1 / Δr versus 1 / t and perform linear regression fitting to obtain a slope of and a vertical axis intercept of where Δr max is the maximum value of Δr, and t 0.5r is the production days when Δr = 0.5Δr max . The prediction model for the change of water-gas ratio with production days is:

[0092] In an embodiment of the method for determining the production mode of deep coalbed methane wells of the present application, referring to Figure 3 , it may specifically include the following content:

[0093] Step S301: Construct a prediction model for the change of bottom-hole pressure with production days according to the corresponding relationship between the bottom-hole pressure at any production time, the production days after initial stable gas production, and the bottom-hole pressure at the time of initial stable gas production;

[0094] Step S302: Determine the bottom-hole pressure at any production time according to the bottom-hole pressure and production days change prediction model.

[0095] In this embodiment, the bottom-hole pressure at the initial stable gas production is p 0 , the bottom-hole pressure at any production time is p i , p i The difference from p 0 is Δp, and the production days are calculated as t after the initial stable gas production. Make a graph of 1 / Δp versus 1 / t and perform linear regression fitting to obtain a slope of and a vertical-axis intercept of where Δp max is the maximum value of Δp, t 0.5p is the production days when Δp = 0.5Δp max , and the bottom-hole pressure and production days change prediction model is

[0096] In an embodiment of the method for determining the production mode of a deep coalbed methane well in the present application, referring to Figure 4 , it may further specifically include the following content:

[0097] Step S401: Determine the bottom-hole pressure and water-gas ratio calculation model according to the water-gas ratio and production days change prediction model and the bottom-hole pressure and production days change prediction model corresponding to the water-gas ratio and bottom-hole pressure at any production time;

[0098] Step S402: Determine the production pressure coefficient curve at different water-gas ratios according to the bottom-hole pressure and water-gas ratio calculation model and the preset hydrostatic pressure of the gas well vertical depth.

[0099] In this embodiment, take the ratio of the bottom-hole pressure p i to the hydrostatic pressure p H of the gas well vertical depth as the production pressure coefficient αp i , and draw the production pressure coefficient curve at different water-gas ratios.

[0100] Bottom-hole pressure and water-gas ratio calculation model:

[0101] Production pressure coefficient calculation model:

[0102] In an embodiment of the method for determining the production mode of a deep coalbed methane well in the present application, referring to Figure 5 , it may further specifically include the following content:

[0103] Step S501: Determine the corresponding multiphase flow model according to the water-gas ratio and production days change prediction model;

[0104] Step S502: Based on the multiphase pipe flow model, perform nodal analysis with the external transmission pipeline network pressure as the wellhead pressure to determine the critical flowing pressure coefficient curves at different gas-water ratios.

[0105] In this embodiment, select the multiphase pipe flow model according to the gas-water ratio, use the external transmission pipeline network pressure as the wellhead pressure, and calculate the critical bottom-hole pressure and critical pressure coefficient αp under different flowing production modes, gas production rates, and gas-water ratios through nodal analysis. c Draw the critical flowing pressure coefficient curves at different gas-water ratios.

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

[0107] In an embodiment of the method for determining the production mode of deep coalbed methane wells in this application, refer to Figure 6 , and it may specifically include the following content:

[0108] Step S601: Superimpose the production pressure coefficient curve and the critical flowing pressure coefficient curve to obtain the corresponding production mode conversion selection chart;

[0109] Step S602: Determine the corresponding production mode according to the curve height and curve intersection point of the production pressure coefficient curve and the critical flowing pressure coefficient curve in the production mode conversion selection chart.

[0110] In this embodiment, superimpose the production pressure coefficient curve drawn from production data and the critical pressure coefficient curve on one graph to obtain the production mode conversion selection chart for flowing and mechanical production. In the graph, if the production pressure coefficient is higher than the critical pressure coefficient (αp i >αp c ), flowing production can be adopted; when the production pressure coefficient is lower than the critical pressure coefficient (αp i ≤αp c ), mechanical production is required.

[0111] In order to achieve efficient drainage gas production and production control, this application provides an embodiment of a device for determining the production mode of deep coalbed methane wells, which can implement all or part of the content of the method for determining the production mode of deep coalbed methane wells. Refer to Figure 7 , and the device for determining the production mode of deep coalbed methane wells specifically includes the following content:

[0112] The model prediction module 10 is configured to determine the water-gas ratio and bottom-hole pressure at any production time according to 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 of the change of water-gas ratio with production days and the change of bottom-hole pressure with production days.

[0113] The curve determination module 20 is configured to determine the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time, and determine the critical flowing pressure coefficient curve of natural flow at different water-gas ratios according to the preset multiphase pipe flow model.

[0114] The production mode determination module 30 is configured to determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical flowing pressure coefficient curve of natural flow.

[0115] As can be seen from the above description, the device for determining the production mode of a deep coalbed methane well provided by the embodiment of the present application can provide a basis for the selection of the production mode of a deep coalbed methane well through the method for judging the conversion between natural flow and mechanical production and the selection chart for a deep coalbed methane well in the present application, so as to realize efficient drainage gas production and production control, significantly improve the stability and continuity of liquid drainage production, realize efficient liquid drainage and a steady increase in gas production, and thus improve the recovery rate. The present invention is widely applicable to deep coalbed methane wells, and therefore has a broad application prospect and significant economic benefits.

[0116] In an embodiment of the device for determining the production mode of a deep coalbed methane well of the present application, referring to Figure 8 , the model prediction module 10 includes:

[0117] The water-gas ratio model construction unit 11 is configured to construct a prediction model of the change of water-gas ratio with production days according to the correspondence between the water-gas ratio at any production time, 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 configured to determine the water-gas ratio at any production time according to the prediction model of the change of water-gas ratio with production days.

[0119] In an embodiment of the device for determining the production mode of a deep coalbed methane well of the present application, referring to Figure 9 , the model prediction module 10 further includes:

[0120] The bottom-hole pressure model construction unit 13 is configured to construct a prediction model of the change of bottom-hole pressure with production days according to the correspondence between the bottom-hole pressure at any production time, the number of production days after the initial stable gas production, and the bottom-hole pressure at the initial stable gas production.

[0121] The bottom-hole pressure model prediction unit 14 is configured to determine the bottom-hole pressure at any production time according to the prediction model of the change of bottom-hole pressure with production days.

[0122] In an embodiment of the deep coalbed methane well production mode determination device of the present application, refer to Figure 10 , the curve determination module 20 includes:

[0123] A calculation model construction unit 21, configured to determine a bottom hole pressure and water-gas ratio calculation model according to a water-gas ratio and production days change prediction model corresponding to the water-gas ratio and bottom hole pressure at any production time and a bottom hole pressure and production days change prediction model;

[0124] A coefficient curve determination unit 22, configured to determine a production pressure coefficient curve at different water-gas ratios according to the bottom hole pressure and water-gas ratio calculation model and a preset static water pressure of the gas well vertical depth.

[0125] In an embodiment of the deep coalbed methane well production mode determination device of the present application, refer to Figure 11 , the curve determination module 20 further includes:

[0126] A multiphase pipe flow model determination unit 23, configured to determine a corresponding multiphase pipe flow model according to the water-gas ratio and production days change prediction model;

[0127] A node analysis unit 24, configured to perform node analysis with the external transmission network pressure as the wellhead pressure according to the multiphase pipe flow model, and determine a self-flowing critical pressure coefficient curve at different water-gas ratios.

[0128] In an embodiment of the deep coalbed methane well production mode determination device of the present application, refer to Figure 12 , the production mode determination module 30 includes:

[0129] A curve superposition unit 31, configured to superpose the production pressure coefficient curve and the self-flowing critical pressure coefficient curve to obtain a corresponding production mode conversion selection chart;

[0130] A production mode determination unit 32, configured to determine a corresponding production mode according to the curve height and curve intersection point of the production pressure coefficient curve and the self-flowing critical pressure coefficient curve in the production mode conversion selection chart.

[0131] To further illustrate the present solution, the present application also provides a specific application example of a deep coalbed methane well production mode determination method implemented by using the above deep coalbed methane well production mode determination device, which specifically includes the following content:

[0132] 1. Establish a water-gas ratio, bottom hole pressure and production days change prediction model.

[0133] The water-gas ratio at the initial stable gas production is r 0 , the water-gas ratio at any production time is r i , ri The difference from r 0 is Δr, and the production days t are calculated from the initial stable gas production.

[0134] Refer to Figure 13 and Figure 14 , plot the relationship diagram of 1 / Δr and 1 / t and perform linear regression fitting to obtain the slope and the vertical axis intercept where Δr max is the maximum value of Δr, and t 0.5r is the production days when Δr = 0.5Δr max . The prediction model for the change of water-gas ratio and production days is as follows:

[0135] Refer to Figure 13 and Figure 15 , the bottom-hole pressure at the initial stable gas production is p 0 , and the bottom-hole pressure at any production time is p i , the difference between p i and p 0 is Δp, and the production days t are calculated from the initial stable gas production. Plot the relationship diagram of 1 / Δp and 1 / t and perform linear regression fitting to obtain the slope and the vertical axis intercept where Δp max is the maximum value of Δp, and t 0.5p is the production days when Δp = 0.5Δp max . The prediction model for the change of bottom-hole pressure and production days is

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

[0137] Refer to Figure 16 , take the ratio of the bottom-hole pressure p i to the hydrostatic pressure p H of the gas well vertical depth as the production pressure coefficient αp i , and plot the production pressure coefficient curves under different water-gas ratios.

[0138] Calculation model for bottom-hole pressure and water-gas ratio:

[0139] Calculation model for production pressure coefficient:

[0140] 3. Select the multiphase flow model according to the water-gas ratio. Take the external transmission pipeline network pressure as the wellhead pressure, and calculate the critical bottom-hole pressure and critical pressure coefficient αp under different flowing production modes, gas production rates and water-gas ratios through nodal analysis c , and plot the flowing critical pressure coefficient curves under different water-gas ratios.

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

[0142] 4. Superimpose the production pressure coefficient curve and the critical pressure coefficient curve plotted from production data on one graph to obtain the conversion selection chart for natural flow and artificial lift production methods. In the chart, if the production pressure coefficient is higher than the critical pressure coefficient (αp i >αp c ), natural flow production can be adopted. When the production pressure coefficient is lower than the critical pressure coefficient (αp i ≤αp c ), artificial lift production is required.

[0143] Specifically, see Figure 17 For the production pressure coefficient curve being higher than the natural flow critical pressure curves of the casing-tubing annulus and the plain casing, but lower than the natural flow critical pressure curve of the tubing, natural flow production through the casing-tubing annulus can be adopted, and natural flow production through the tubing cannot be adopted. When the water-gas ratio is lower than the intersection point A of the production pressure coefficient curve and the natural flow critical pressure curve of the casing-tubing annulus in the figure, natural flow production through the casing-tubing annulus will not be possible, and it is necessary to switch to natural flow production through the plain casing. When the water-gas ratio is lower than the intersection point B of the production pressure coefficient curve and the natural flow critical pressure curve of the plain casing in the figure, natural flow production will not be possible, and it is necessary to switch to artificial lift production.

[0144] See Figure 18 For the production pressure coefficient curve of the artificial lift production well in the early stage being lower than the natural flow critical pressure coefficient curve of the 88.9 mm tubing, artificial lift production method is adopted. As the liquid drainage and pressure reduction increase the gas production and decrease the water-gas ratio, when the water-gas ratio is lower than the position of the intersection point A in the figure, the production pressure coefficient curve is higher than the natural flow critical pressure coefficient curve of the 88.9 mm tubing, and the artificial lift production is converted to natural flow production through the tubing. When the water-gas ratio is lower than the intersection point B, the natural flow production is converted to artificial lift production. As shown in the figure, when 73 mm or 60.3 mm tubing is used, the production pressure coefficient curves in the early and middle stages are higher than the natural flow critical pressure coefficient curves, that is, natural flow production is maintained. Therefore, selecting an appropriate tubing according to the chart can significantly extend the natural flow production time.

[0145] It can be seen from the above that through the on-site application and implementation of the present invention, the stability and continuity of liquid drainage production can be significantly improved, efficient liquid drainage and a steady increase in gas production can be achieved, thereby improving the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

[0146] At the hardware level, in order to achieve efficient drainage gas production and production control, this application provides an embodiment of an electronic device for implementing all or part of the content in the method for determining the production mode of deep coalbed methane wells. The electronic device specifically includes the following content:

[0147] A processor, a memory, a communications interface, and a bus; wherein, the processor, the memory, and the communications interface complete communication with each other through the bus; the communications interface is used to implement information transmission between the device for determining the production mode of deep coalbed methane wells and related devices such as the core business system, the user terminal, and the relevant database, etc. The logic controller can be a desktop computer, a tablet computer, a mobile terminal, etc., and this embodiment is not limited thereto. In this embodiment, the logic controller can be implemented with reference to the embodiments of the method for determining the production mode of deep coalbed methane wells and the embodiments of the device for determining the production mode of deep coalbed methane wells in the embodiments, and the content is incorporated herein, and the repeated parts will not be described again.

[0148] It can be understood that the user terminal can include a smart phone, a tablet electronic device, a network set-top box, a portable computer, a desktop computer, a personal digital assistant (PDA), a vehicle-mounted device, a smart wearable device, etc. Among them, the smart wearable device can include smart glasses, a smart watch, a smart bracelet, etc.

[0149] In practical applications, part of the method for determining the production mode of deep coalbed methane wells can be executed on the electronic device side as described above, or all operations can be completed in the client device. Specifically, it can be selected according to the processing capacity of the client device and the limitations of the user usage scenario, etc. This application does not make a limitation in this regard. If all operations are completed in the client device, the client device may further include a processor.

[0150] The above-mentioned client device can have a communication module (i.e., a communication unit), and can be communicatively connected to a remote server to achieve data transmission with the server. The server can include a server on the side of the task scheduling center, and in other implementation scenarios, it can also include a server of the intermediate platform, such as a server of a third-party server platform communicatively linked to the task scheduling center server. The server can include a single computer device, or can include a server cluster composed of multiple servers, or a server structure of a distributed device.

[0151] Figure 19 This is a schematic block diagram of the system composition of the electronic device 9600 according to the embodiment of this application. As Figure 19As 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 should be noted that the Figure 19 is exemplary; other types of structures may also be used to supplement or replace this structure to achieve telecommunication functions or other functions.

[0152] In one embodiment, the function of the method for determining the production mode of deep coalbed methane wells may be integrated into the central processing unit 9100. Among them, the central processing unit 9100 may be configured to perform the following controls:

[0153] Step S101: According to 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 of the change of the water-gas ratio with the production days and the change of the bottom-hole pressure with the production days, determine the water-gas ratio and bottom-hole pressure at any production time;

[0154] Step S102: According to the water-gas ratio and bottom-hole pressure at any production time, determine the production pressure coefficient curve at different water-gas ratios, and determine the critical flowing pressure coefficient curve at different water-gas ratios according to the preset multiphase pipe flow model;

[0155] Step S103: Determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical flowing pressure coefficient curve.

[0156] As can be seen from the above description, the electronic device provided by the embodiments of the present application, through the method for judging the conversion between the flowing and artificial lift production of deep coalbed methane wells and the selection chart provided by the present application, provides a basis for the selection of the production mode of deep coalbed methane wells, thereby realizing efficient drainage gas production and production control, significantly improving the stability and continuity of liquid drainage production, realizing efficient liquid drainage and a steady increase in gas production, and thus improving the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

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

[0158] As Figure 19 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 should be noted that the electronic device 9600 does not necessarily have to include all the components shown Figure 19 ; in addition, the electronic device 9600 may further include Figure 19For components not shown herein, reference may be made to the prior art.

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

[0160] Among them, the memory 9140 can be, for example, one or more of a buffer, a flash memory, a hard drive, a removable medium, a volatile memory, a non-volatile memory, or other suitable devices. It can store the above information related to failures, and can also store programs for executing relevant information. And the central processing unit 9100 can execute the programs stored in the memory 9140 to achieve information storage or processing, etc.

[0161] The input unit 9120 provides inputs to the central processing unit 9100. The input unit 9120 is, for example, a key or a touch input device. The power supply 9170 is used to supply power to the electronic device 9600. The display 9160 is used to display display objects such as images and texts. The display can be, for example, an LCD display, but is not limited thereto.

[0162] The memory 9140 can be a solid-state memory. For example, a read-only memory (ROM), a random access memory (RAM), a SIM card, etc. It can also be a memory that stores information even when powered off, can be selectively erased and has more data. Examples of such a memory are sometimes referred to as EPROMs, etc. 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 can include an application / function storage section 9142, which is used to store application programs and function programs or the processes for operating the electronic device 9600 through the central processing unit 9100.

[0163] The memory 9140 can also include a data storage section 9143, which is used to store data, such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. The driver storage section 9144 of the memory 9140 can include various drivers of the electronic device for communication functions and / or for performing other functions of the electronic device (such as a messaging application, an address book application, 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 processor 9100 to provide input signals and receive output signals, which can be the same as in the case of a conventional mobile communication terminal.

[0165] Based on different communication technologies, multiple communication modules 9110 can be provided in the same electronic device, such as a cellular network module, a Bluetooth module, and / or a wireless local area network module, etc. The communication module (transmitter / receiver) 9110 is also coupled to the speaker 9131 and the microphone 9132 via the audio processor 9130 to provide an audio output via the speaker 9131 and receive an audio input from the microphone 9132, thereby implementing the usual telecommunications functions. The audio processor 9130 can include any suitable buffers, decoders, amplifiers, etc. In addition, the audio processor 9130 is also coupled to the central processor 9100, so that recording can be performed on the local machine through the microphone 9132, and the sound stored on the local machine can be played through the speaker 9131.

[0166] Embodiments of the present application also provide a computer-readable storage medium capable of implementing all steps in the method for determining the production mode of a deep coalbed methane well where the execution subject in the above embodiments is a server or a client. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, all steps in the method for determining the production mode of a deep coalbed methane well where the execution subject in the above embodiments is a server or a client are implemented. For example, when the processor executes the computer program, the following steps are implemented:

[0167] Step S101: Determine the water-gas ratio and bottom-hole pressure at any production time according to 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 water-gas ratio and production days change prediction model and bottom-hole pressure and production days change prediction model;

[0168] Step S102: Determine the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time, and determine the self-flowing critical pressure coefficient curve at different water-gas ratios according to the preset multiphase pipe flow model;

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

[0170] As can be seen from the above description, the computer-readable storage medium provided by the embodiments of the present application provides a basis for the selection of the production mode of deep coalbed methane wells through the method and selection chart for judging the conversion between natural flow and mechanical production of deep coalbed methane wells in the present application, so as to realize efficient drainage gas production and production control, significantly improve the stability and continuity of liquid drainage production, realize efficient liquid drainage and a steady increase in gas production, and thus improve the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

[0171] An embodiment of the present application also provides a computer program product capable of implementing all steps in the method for determining the production mode of deep coalbed methane wells where the execution subject in the above embodiments is a server or a client. When the computer program / instructions are executed by a processor, the steps of the method for determining the production mode of deep coalbed methane wells are implemented. For example, the computer program / instructions implement the following steps:

[0172] Step S101: Determine the water-gas ratio and bottom-hole pressure at any production time according to 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 the change of water-gas ratio with production days and the change of bottom-hole pressure with production days.

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

[0174] Step S103: Determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical self-flow pressure coefficient curve.

[0175] As can be seen from the above description, the computer program product provided by the embodiments of the present application provides a basis for the selection of the production mode of deep coalbed methane wells through the method and selection chart for judging the conversion between natural flow and mechanical production of deep coalbed methane wells in the present application, so as to realize efficient drainage gas production and production control, significantly improve the stability and continuity of liquid drainage production, realize efficient liquid drainage and a steady increase in gas production, and thus improve the recovery rate. The present invention is widely applicable to deep coalbed methane wells, so it has broad application prospects and significant economic benefits.

[0176] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a device, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented 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] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (devices), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, and the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0178] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0179] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one flow Figure 1 one flow or multiple flows and / or blocks Figure 1 or multiple blocks.

[0180] Specific embodiments are applied in the present invention to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A method for determining the production mode of deep coalbed methane wells, characterized in that, the method includes: Determining the water-gas ratio and bottom-hole pressure at any production time according to 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 of the change of water-gas ratio with production days and the change of bottom-hole pressure with production days; Determining the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time, and determining the critical flowing pressure coefficient curve at different water-gas ratios according to the preset multiphase flow model; Determining the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the critical flowing pressure coefficient curve.

2. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, the determining of the water-gas ratio at any production time according to the water-gas ratio at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction model of the change of water-gas ratio with production days includes: Constructing a prediction model of the change of water-gas ratio with production days according to the corresponding relationship between the water-gas ratio at any production time, the number of production days after the initial stable gas production, and the water-gas ratio at the initial stable gas production; Determining the water-gas ratio at any production time according to the prediction model of the change of water-gas ratio with production days.

3. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, the determining of the bottom-hole pressure at any production time according to the bottom-hole pressure at the initial stable gas production, the number of production days after the initial stable gas production, and the preset prediction model of the change of bottom-hole pressure with production days further includes: Constructing a prediction model of the change of bottom-hole pressure with production days according to the corresponding relationship between the bottom-hole pressure at any production time, the number of production days after the initial stable gas production, and the bottom-hole pressure at the initial stable gas production; Determining the bottom-hole pressure at any production time according to the prediction model of the change of bottom-hole pressure with production days.

4. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, the determining of the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time includes: Determining a calculation model of bottom-hole pressure and water-gas ratio according to the prediction models of the change of water-gas ratio with production days and the change of bottom-hole pressure with production days corresponding to the water-gas ratio and bottom-hole pressure at any production time; Determining the production pressure coefficient curve at different water-gas ratios according to the calculation model of bottom-hole pressure and water-gas ratio and the hydrostatic pressure of the well depth of the preset gas well.

5. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, the determining of the critical flowing pressure coefficient curve at different water-gas ratios according to the preset multiphase flow model includes: Determining the corresponding multiphase flow model according to the prediction model of the change of water-gas ratio with production days; Performing nodal analysis with the external pipeline network pressure as the wellhead pressure according to the multiphase flow model to determine the critical flowing pressure coefficient curve at different water-gas ratios.

6. The method for determining the production mode of deep coalbed methane wells according to claim 1, characterized in that, Determining the corresponding production mode of a deep coalbed methane well according to the production pressure coefficient curve and the flowing critical pressure coefficient curve includes: Superposing the production pressure coefficient curve and the flowing critical pressure coefficient curve to obtain a corresponding production mode conversion selection chart; Determining the corresponding production mode according to the curve height and the curve intersection point of the production pressure coefficient curve and the flowing critical pressure coefficient curve in the production mode conversion selection chart.

7. A device for determining the production mode of a deep coalbed methane well, characterized in that, it includes: A model prediction module, configured to determine the water-gas ratio and bottom-hole pressure at any production time according to the water-gas ratio and bottom-hole pressure at the initial stable gas production, the production days after the initial stable gas production, and a preset water-gas ratio and production days change prediction model and a bottom-hole pressure and production days change prediction model; A curve determination module, configured to determine the production pressure coefficient curve at different water-gas ratios according to the water-gas ratio and bottom-hole pressure at any production time, and determine the flowing critical pressure coefficient curve at different water-gas ratios according to a preset multiphase flow model; A production mode determination module, configured to determine the corresponding production mode of the deep coalbed methane well according to the production pressure coefficient curve and the flowing critical pressure coefficient curve.

8. The device for determining the production mode of a deep coalbed methane well according to claim 7, characterized in that, the model prediction module includes: A water-gas ratio model construction unit, configured to construct a water-gas ratio and production days change prediction model according to the correspondence between the water-gas ratio at any production time, the 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, configured to determine the water-gas ratio at any production time according to the water-gas ratio and production days change prediction model.

9. The device for determining the production mode of a deep coalbed methane well according to claim 7, characterized in that, the model prediction module further includes: A bottom-hole pressure model construction unit, configured to construct a bottom-hole pressure and production days change prediction model according to the correspondence between the bottom-hole pressure at any production time, the production days after the initial stable gas production, and the bottom-hole pressure at the initial stable gas production; A bottom-hole pressure model prediction unit, configured to determine the bottom-hole pressure at any production time according to the bottom-hole pressure and production days change prediction model.

10. The device for determining the production mode of a deep coalbed methane well according to claim 7, characterized in that, the curve determination module includes: A calculation model construction unit, configured to determine a bottom-hole pressure and water-gas ratio calculation model according to the water-gas ratio and production days change prediction model and the bottom-hole pressure and production days change prediction model corresponding to the water-gas ratio and bottom-hole pressure at any production time; A coefficient curve determination unit, configured to determine the production pressure coefficient curve at different water-gas ratios according to the bottom-hole pressure and water-gas ratio calculation model and the preset static water pressure of the gas well vertical depth.

11. The device for determining the production mode of a deep coalbed methane well according to claim 7, characterized in that, the curve determination module further includes: A multiphase flow model determination unit, configured to determine a corresponding multiphase flow model according to the water-gas ratio and production days change prediction model; A node analysis unit, configured to perform node analysis with the external transmission pipeline network pressure as the wellhead pressure according to the multiphase pipe flow model, and determine the critical flowing pressure coefficient curves at different gas-water ratios.

12. The deep coalbed methane well production mode determination device according to claim 7, wherein, the production mode determination module includes: a curve superposition unit, configured to perform curve superposition on the production pressure coefficient curve and the critical flowing pressure coefficient curve to obtain a corresponding production mode conversion selection chart; a production mode determination unit, configured to determine the corresponding production mode according to the curve height and curve intersection point of the production pressure coefficient curve and the critical flowing pressure coefficient curve in the production mode conversion selection chart.

13. An electronic device, including a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein, when the processor executes the program, the steps of the deep coalbed methane well production mode determination method according to any one of claims 1 to 6 are implemented.

14. A computer-readable storage medium, on which a computer program is stored, wherein, when the computer program is executed by a processor, the steps of the deep coalbed methane well production mode determination method according to any one of claims 1 to 6 are implemented.

15. A computer program product, including a computer program / instructions, wherein, when the computer program / instructions are executed by a processor, the steps of the deep coalbed methane well production mode determination method according to any one of claims 1 to 6 are implemented.

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