Method for automatically determining reasonable working system of gas well in intelligent gas field

Abstract

The invention discloses a method for automatically determining a reasonable working system of a gas well for an intelligent gas field, and relates to the technical field of oil-gas field development, the gas well is divided into a pure gas well, a water breakthrough risk well and a water breakthrough well according to whether the gas well produces water and the distance from the front edge of water invasion, and then the upper limit and the lower limit of production allocation of the pure gas well are automatically determined to be the reasonable working system according to the data driving technology. And the production allocation upper limit of the water breakthrough risk well and the production allocation lower limit of the water breakthrough well are input into the integrated simulation model, the integrated simulation model is operated for optimization calculation, the optimal working system of the gas well is obtained, and the problem that in the prior art, the production allocation efficiency of the gas well is low is solved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field development, and in particular to a method for automatically determining a reasonable working system of a gas well in an intelligent gas field. Background Art

[0002] Gas well production allocation is an important task in gas field development. Scientific and reasonable production allocation is the basis for ensuring efficient development of gas fields. Common methods for gas well production allocation include empirical method, gas production indicator curve method, node analysis method, numerical simulation method, etc. At present, domestic gas well production allocation is mostly based on multi-point isochronous well testing, modified isochronous well testing and single-point test method to calculate the open-flow rate, and 1 / 6-1 / 2 of the open-flow rate is used as the allocation production. The pressure and production fluctuations are observed through test production, and the working system is adjusted to keep the gas well production and pressure relatively stable. Finally, the gas well working system is determined. This method only considers the gas reservoir in the production allocation process, and does not consider the mutual influence of the global production system and the future changes of the production system, and the production allocation efficiency is low. Summary of the invention

[0003] The purpose of the present invention is to provide a method for automatically determining a reasonable working system of a gas well in an intelligent gas field, which can effectively solve the problem of low gas well production efficiency in the prior art. The present invention is achieved through the following technical solutions: A method for automatically determining a reasonable working system of a gas well in an intelligent gas field, which divides the gas wells into three categories: pure gas wells, water-risk wells, and water-exposed wells according to whether the gas wells produce water and the distance from the water invasion front. Then, by using data-driven technology, the upper and lower limits of the production allocation of pure gas wells, the upper limit of the production allocation of water-risk wells, and the lower limit of the production allocation of water-exposed wells are automatically input into an integrated simulation model, and the integrated simulation model is run for optimization calculation to obtain the optimal working system of the gas wells.

[0004] Furthermore, the classification criteria for gas wells are as follows: Pure gas well: The gas well does not produce water, that is, the water-gas ratio is less than 2m 3 / 10 4 m 3 , and more than one well spacing away from the water invasion front; Wells with water risk: gas wells that do not produce water but are within one well spacing from the water invasion front; Water well: Water has been seen in the gas well, that is, the water-gas ratio is greater than 2m 3 / 10 4 m 3 .

[0005] Furthermore, the method for determining the upper and lower limits of the production allocation of the pure gas well comprises the following steps: Step a. Take the production dynamic data of pure gas wells in the past year, and divide the production history dynamic data of pure gas wells in the past year into n stages according to the division criteria that the working system of the gas wells does not change and the daily gas production is stable; Step b. Calculate the gas production per unit wellhead pressure drop at each stage; Step c. Regression gas well daily gas production and gas production per unit wellhead pressure drop correlation formula; Step d. Applying the gas well model to simulate the relationship between the daily gas production of the gas well and the wellhead pressure; Step e. Calculate the remaining recoverable reserves by calculating the wellhead pressure and gas production per unit wellhead pressure drop; Step f. According to step e, draw a relationship curve between daily gas production and remaining recoverable reserves, take the daily gas production with the maximum remaining recoverable reserves as the optimal production allocation value, determine the optimal production allocation area, the minimum daily gas production in the area is the lower limit of production allocation, and the maximum daily gas production in the area is the upper limit of production allocation.

[0006] Furthermore, in step a, the daily gas production stability as the division standard means that the maximum value of the stage minus the minimum value of the stage divided by the average value of the stage is less than 5%, satisfying the relationship (1): (1), In the formula, : Maximum daily gas production in the stage; : Minimum daily gas production in the stage; : Average daily gas production in the stage.

[0007] Furthermore, in step b, the gas production per unit wellhead pressure drop of n stages is calculated according to the divided stages, and the gas production per unit wellhead pressure drop of the stage is calculated by dividing the cumulative gas production of the stage by the wellhead pressure drop of the stage. , satisfying the relationship (2): (2), Where: : Cumulative gas production at the end of the stage; : Cumulative gas production at the initial stage; : wellhead pressure at the end of the stage; : Wellhead pressure at the initial stage.

[0008] Furthermore, in step c, the method for regressing the correlation between the daily gas production of the gas well and the gas production per unit wellhead pressure drop is: using Excel software to calculate the daily gas production of the gas well at each stage and gas production per unit wellhead pressure drop Performing correlation regression, we get equation (3): (3), Where: a : Linear regression coefficient, representing the slope; b linear regression coefficient, representing the intercept.

[0009] Furthermore, in step d, the gas well model is applied to calculate the daily gas production according to the node analysis method. Wellhead pressure The relationship is as follows: (4).

[0010] Further, in step e, by wellhead pressure and gas production per unit wellhead pressure drop Calculate remaining recoverable reserves , satisfying the relationship (5): (5).

[0011] Furthermore, in step f, according to formula (5) in step e, a relationship curve between daily gas production and remaining recoverable reserves is drawn, and the daily gas production of the maximum remaining recoverable reserves is taken as the optimal production allocation value. The area between 98% of the maximum remaining recoverable reserves and the maximum remaining recoverable reserves is determined as the optimal production allocation area, the minimum daily gas production in the area is the lower limit of the production allocation, and the maximum daily gas production in the area is the upper limit of the production allocation.

[0012] Furthermore, the upper limit of the production allocation of the water-risk well is the production corresponding to the upper limit of the production pressure difference set for the water-risk well; and the lower limit of the production allocation of the water-risk gas well is the critical production of the gas well.

[0013] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention provides a method that can consider the coordinated operation of the global production system, can consider future changes in the production system to improve gas reservoir recovery, and can use data-driven technology to quickly and automatically determine the optimal working system of pure gas wells, water-risk wells, and water-exposed wells, laying the foundation for the comprehensive construction of intelligent gas fields.

[0014] 2. In the present invention, based on the integrated model of "gas reservoir-wellbore-ground", the present invention utilizes the currently more mature data-driven technology to open up the whole process of automated operation from data acquisition, data transmission, data processing, to integrated model data loading, calculation, and output of results, and comprehensively considers the production constraints of different types of gas wells (pure gas wells, water-risk wells, and water-seeking wells), and uses the integrated model global optimization calculation to determine the best working system for gas wells, thereby improving the scientificity and timeliness of decision-making. For example: For pure gas wells, the actual production data of the gas wells for nearly one year is combined with the VLP / IPR node analysis method to calculate the relationship between the gas well production and the remaining recoverable reserves, and the gas well production within the range of 98% of the maximum value of the remaining recoverable reserves is selected as the optimal production range, and its minimum value is set as the lower limit of production allocation, and the maximum value is set as the upper limit of production allocation. For water-risk wells, an upper limit of production pressure difference is set to slow down the advancement speed of edge and bottom water. For the water wells that have been seen, the present invention adopts the IPR / VLP node intersection method to calculate the critical gas production of the water wells that have been seen as the lower limit of production allocation, so as to ensure that the final result is more accurate and the working system is more efficient.

[0015] 3. In the present invention, according to the unique characteristics of pure gas wells, a method suitable for production allocation of pure gas wells is disclosed. First, the upper and lower limits of the production allocation of pure gas wells need to be determined, including the steps of: dividing the production dynamic data of the pure gas wells in the most recent year into n stages for research, and then calculating the gas production per unit wellhead pressure drop in each stage; then regressing the correlation between the daily gas production of the gas well and the gas production per unit wellhead pressure drop; using a gas well model to simulate the relationship between the daily gas production of the gas well and the wellhead pressure; calculating the remaining recoverable reserves through the wellhead pressure and the gas production per unit wellhead pressure drop; drawing a relationship curve between daily gas production and remaining recoverable reserves, and determining the optimal production allocation area, the minimum daily gas production in the area is the lower limit of production allocation, and the maximum daily gas production in the area is the upper limit of production allocation. The upper and lower limits of production allocation obtained by this method provide reliable data materials for the arrangement of the subsequent work system, so that the final work system arrangement is reasonable and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the relationship curve between daily gas production and remaining recoverable reserves.

[0017] Figure 2 is the critical yield analysis curve.

[0018] Figure 3 It is the curve of daily gas production, wellhead oil pressure, and gas production per unit pressure drop at the wellhead of W1 well.

[0019] Figure 4 This is the relationship curve between the daily gas production of Well W1 and the gas production per unit pressure drop.

[0020] Figure 5 This is the relationship curve between the daily gas production of Well W1 and the remaining recoverable reserves.

[0021] Figure 6 It is a table of daily gas production and gas production per unit pressure drop at the wellhead for each stage of Well W1.

[0022] Figure 7 This is the relationship table between the daily gas production of W1 well and the remaining recoverable reserves. DETAILED DESCRIPTION

[0023] The following is a further description of a method for automatically determining a reasonable working system of a gas well in an intelligent gas field provided by the present invention through an embodiment. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. The technical personnel in the relevant field can make some non-essential improvements and adjustments to the present invention according to the above invention content and implement it specifically, which still belongs to the scope of protection of the present invention.

[0024] The present invention is based on the integrated model of "gas reservoir-wellbore-ground" and uses data-driven technology to open up the entire process of automated operation from data acquisition, data transmission, data processing to integrated model data loading, calculation, and results output. It also comprehensively considers the production constraints of different types of gas wells (pure gas wells, water risk wells, and water wells), and uses the integrated model to globally optimize the calculation to determine the optimal working system for the gas wells, thereby improving the scientific nature and timeliness of decision-making. Example

[0025] Taking a gas reservoir in Sichuan as an example, the field metering parameters of the gas reservoir mainly include the daily gas production of the gas well, the daily water production, the wellhead pressure and the pipeline metering pressure. The gas reservoir has adopted the IPM software of PETEX to complete the construction of the gas reservoir-wellbore-ground integrated simulation model, and on this basis, the gas well is automatically optimized for production allocation.

[0026] In this embodiment, gas wells are divided into three categories according to the following standards: pure gas wells, water-risk wells, and water-exposed wells.

[0027] Pure gas well: gas well does not produce water (water-gas ratio is less than 2m 3 / 10 4 m 3 ) and more than one well spacing away from the water invasion front; Wells with water risk: gas wells that do not produce water but are within one well spacing from the water invasion front; Water wells: Water has been found in gas wells (water-gas ratio is greater than 2m 3 / 10 4 m 3 ).

[0028] The classification of gas well types is based on the gas-water distribution and production conditions of gas wells, and divides gas wells into three categories: pure gas wells, water-risk wells, and water-exposed wells. The classification criteria are as follows: Pure gas well: gas well does not produce water (water-gas ratio is less than 2m3 / 10 4 m 3 ) and more than one well spacing away from the water invasion front; Wells with water risk: gas wells that do not produce water but are within one well spacing from the water invasion front; Water wells: Water has been found in gas wells (water-gas ratio is greater than 2m 3 / 10 4 m 3 ).

[0029] Then, according to the characteristics of different types of gas wells, appropriate gas well production restriction conditions are adopted, as follows: 1. Pure gas well In this embodiment, the pure gas well uses the actual production data of the gas well in the past year combined with the VLP / IPR node analysis method to calculate the relationship between the gas well production and the remaining recoverable reserves, and selects the gas well production within the 98% interval of the maximum value of the remaining recoverable reserves as the optimal production interval, and its minimum value is set as the lower limit of the production allocation, and the maximum value is set as the upper limit of the production allocation. The specific operation method for obtaining the upper and lower limits of the production allocation for pure gas wells refers to the following steps: Step 1: Stage Division The production dynamic data of pure gas wells in the past year are taken, and the daily gas production is stable as the division standard without changing the working system of the gas well. The production historical dynamic data of pure gas wells in the past year are divided into n stages. The daily gas production stability standard is the maximum value of the stage minus the minimum value of the stage divided by the average value of the stage, which is less than 5%, that is, the daily gas production satisfies the following relationship (1): (1), Where: : Maximum daily gas production in the stage; : Minimum daily gas production in the stage; : Average daily gas production in the stage.

[0030] Taking Well W1 in a gas reservoir in Sichuan as an example, according to the stable daily gas production, Well W1 is divided into 6 stages, see Appendix. Figure 3 .

[0031] The daily gas production in the first stage is 55.7×10 4 m 3 The second stage daily gas production is 56.3×10 4 m 3 The daily gas production of the third stage is 48.9×10 4 m 3 The fourth stage daily gas production is 47.4×10 4 m 3 The daily gas production in the fifth stage is 44.0×10 4 m 3 The daily gas production in the sixth stage is 50.6×104 m 3 The daily gas production of Well W1 at each stage and the gas production per unit pressure drop at the wellhead are shown in the attached Figure 6 .

[0032] Step 2: Calculate the gas production per unit wellhead pressure drop at each stage According to the divided stages, the gas production per unit wellhead pressure drop of n stages is calculated respectively. The gas production per unit wellhead pressure drop of each stage is calculated by dividing the cumulative gas production of each stage by the wellhead pressure drop of that stage. : (2); Where: : Cumulative gas production at the end of the stage; : Cumulative gas production at the initial stage; : wellhead pressure at the end of the stage; : Wellhead pressure at the initial stage.

[0033] The gas production per unit wellhead pressure drop is calculated by dividing the cumulative gas production in each stage by the wellhead pressure drop in that stage, as shown in formula (2). The gas production per unit wellhead pressure drop of the six stages of Well W1 is calculated. Specifically, the gas production per unit wellhead pressure drop in the first stage is 3274×10 4 m 3 / MPa, the gas production of the second stage wellhead pressure drop is 3284×10 4 m 3 / MPa, the gas production of the wellhead pressure drop in the third stage is 3096×10 4 m 3 / MPa, the gas production of the wellhead pressure drop in the fourth stage is 3147×10 4 m 3 / MPa, the gas production of the wellhead pressure drop in the fifth stage is 3064×10 4 m 3 / MPa, the gas production of the wellhead pressure drop in the sixth stage is 3207×10 4 m 3 / MPa, see Appendix Figure 6 .

[0034] Step 3: Relationship between daily gas production of return gas well and gas production per unit wellhead pressure drop The daily gas production of gas wells at each stage was calculated using Excel software. and gas production per unit wellhead pressure drop Performing correlation regression, we get formula (3): (3); Where: a : Linear regression coefficient, representing the slope; b linear regression coefficient, representing the intercept.

[0035] That is, the daily gas production and gas production per unit wellhead pressure drop in the six stages were regressed using EXCEL software. Figure 4 , the relationship between daily gas production and gas production per unit wellhead pressure drop is as follows: Using the relationship between the daily gas production and the unit wellhead pressure drop, the daily gas production of Well W1 is calculated to be 30×10 4 m 3 , 40×10 4 m 3 , 50×10 4 m 3 , 60×10 4 m 3 ,70×10 4 m 3 The gas production per unit pressure drop at the wellhead is 3532.22×10 4 m 3 3351.06×10 4 m 3 、3169.9×10 4 m 3 ,2988.74×10 4 m 3 ,2807.58×10 4 m 3 , see attached Figure 7 .

[0036] Step 4: Use the gas well model to simulate the relationship between the daily gas production of the gas well and the wellhead pressure The gas well model is the key to connecting the ground gathering and transportation pipeline network model with the gas reservoir model. It is mainly composed of two secondary models. One is the pipe flow model related to the wellbore structure (VLP model for short) that reflects the flow changes of multiphase fluid in the wellbore. The other is the dynamic characteristic model that reflects the flow of formation fluid into the gas well (IPR model for short). When the flow rate flowing from the formation to the bottom of the well is equal to the flow rate flowing from the bottom of the well to the wellhead, the gas well reaches equilibrium. The daily gas production at this time is the daily gas production of the gas well.

[0037] By setting different wellhead pressures in the gas well model, the corresponding daily gas production of the gas well can be calculated. The establishment and calibration of the gas well model can refer to the correction method disclosed in the patent application document with publication number "CN112324428A" and titled "A correction method, device and computer storage medium for gas well inflow dynamic curve". Apply the gas well model and calculate the daily gas production according to the node analysis method Wellhead pressure The relationship is consistent with equation (4): (4).

[0038] In this example, PROSPER software was used to simulate the wellhead pressure of W1 well under different daily gas production rates. The correction method disclosed in the document with publication number "CN112324428A" was adopted. The PROSPER gas well model of W1 well was opened. In the system analysis interface, the daily gas production was set to 30×10 4 m 3 , 40×10 4 m 3 , 50×10 4 m 3 , 60×10 4 m 3 70×10 4 m 3 The corresponding wellhead pressures are calculated to be 24.8MPa, 27.2MPa, 29.5MPa, 31MPa, and 32.2MPa, respectively. The results are shown in the attached Figure 7 .

[0039] Step 5: Through wellhead pressure and gas production per unit wellhead pressure drop Calculate remaining recoverable reserves , satisfying the relationship (5): (5).

[0040] Specifically, calculate the remaining recoverable reserves of W1 gas well at different daily gas production rates: the remaining recoverable reserves of the gas well are obtained by multiplying the wellhead pressure of the gas well by the gas production per unit wellhead pressure drop. Using the wellhead pressure and gas production per unit wellhead pressure drop calculated in steps 3 and 4, calculate the remaining recoverable reservoir of the gas well at different daily gas production rates. The calculation results are shown in the attached Figure 7 .

[0041] Step 6: Determine the upper and lower limits of pure gas well production Formula (5) is used to draw the relationship curve between daily gas production and remaining recoverable reserves. The daily gas production with the maximum remaining recoverable reserves is taken as the optimal production allocation value. The area between 98% of the maximum remaining recoverable reserves and the maximum remaining recoverable reserves is taken as the optimal production allocation area. The minimum daily gas production in the area is the lower limit of production allocation, and the maximum daily gas production in the area is the upper limit of production allocation. Figure 1 .

[0042] Specifically, according to the calculated remaining recoverable reserves of Well W1 at different daily gas production rates, a relationship curve is drawn, and the area between 98% and the maximum value of the remaining recoverable reserves is taken as the optimal production allocation area. The minimum daily gas production in the area is the lower limit of production allocation, and the maximum daily gas production in the area is the upper limit of production allocation. The lower limit of production allocation of Well W1 is 37×10 4 m 3 , the upper limit of production is 57×104 m 3 , see attached Figure 5 shown.

[0043] (II) Gas wells with water risk Referring to the method disclosed in the publication number "CN112324429A" and entitled "Method for Determining Reasonable Production Pressure Differential of Water-Containing Gas Reservoirs", the upper limit of the production pressure differential of gas wells with water risk is obtained, and the output corresponding to the upper limit of the production pressure differential is used as the upper limit of the production allocation of the wells with water risk.

[0044] The specific method includes the following steps: a. Applied to computer equipment, with the edge water of the water reservoir as the center, the area around the edge water is divided into a plurality of annular and concentric circles, each of the circles having at least one gas well; b. determining a target circle among all the circles, the target circle being the circle in which the gas well has not seen water and the closest circle to the gas well in which water has been seen; c. Determine the numerical model of the target circle based on the static parameters of the target circle and the dynamic parameters of the edge water, wherein the static parameters include the porosity, permeability, pressure and thickness of the gas well, and the dynamic parameters include the size of the edge water and the distance between the edge water and the gas well; d. According to the non-steady-state water invasion model and the relevant empirical parameters of the gas well, determine the types of all sensitivity parameters of the gas well, the sensitivity parameters are parameters that affect the water breakthrough time of the gas well, and the sensitivity parameters include production pressure difference; e. According to the numerical model of the target circle, determine the corresponding relationship between the values ​​of the different sensitivity parameters and the water breakthrough time of the gas well; f. Based on the corresponding relationship, establishing a neural network algorithm model of the gas well; g. Calculate the optimal water breakthrough time of the gas well in the target circle according to the neural network algorithm model, and determine the production pressure difference corresponding to the optimal water breakthrough time as the reasonable production pressure difference of the gas well.

[0045] In this embodiment, the production corresponding to the upper limit of the production pressure difference is used as the upper limit of the production allocation of the water breakthrough risk well.

[0046] (III) Water and gas wells have been found The program "LJCL" for automatically calculating the critical production of gas wells with water was written using Python combined with OpenServer software. The program automatically opened the wellbore model of the gas well, then opened the system analysis interface, and automatically adjusted the wellhead pressure until the VLP curve and the IPR curve intersected critically. The daily gas production at this time is the critical production of the gas well with water. This critical production is used as the lower limit of the production allocation of the gas well with water.

[0047] Specifically, the gas well model is applied, and the IPR / VLP node intersection method is used to calculate the critical gas production of the water-seeking gas well that stops production as the lower limit of the production allocation. At a certain moment in the gas well production process, the formation pressure is a constant value, the IPR curve is a fixed curve, and the wellhead pressure is the most critical parameter affecting the VLP curve. When the wellhead pressure increases, the daily gas production decreases, and the VLP curve shifts upward. When the VLP curve reaches the position of the VLP1 curve, the corresponding daily gas production is the critical production under the formation pressure. Figure 2 When the wellhead pressure continues to increase, the VLP curve and the IPR curve have no intersection, that is, the gas well has no production. By writing a program to gradually adjust the wellhead pressure for trial calculation, the critical production of the gas well can be obtained, and the critical production is taken as the lower limit of the production allocation of the gas well with water.

[0048] Finally, using data-driven technology, the upper and lower limits of the production allocation of pure gas wells, the upper limit of the production pressure difference of water-risk wells, and the lower limit of the production allocation of water-seeking wells calculated above are input into the integrated simulation model, and the integrated simulation model is run for optimization calculation to obtain the optimal working system of the gas wells.

[0049] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for automatically determining a reasonable working system of a gas well in an intelligent gas field, characterized in that: According to whether the gas wells produce water and their distance from the water invasion front, the gas wells are divided into three categories: pure gas wells, water risk wells, and water wells. Then, using data-driven technology, the upper and lower limits of the production allocation of pure gas wells, the upper limit of the production allocation of water risk wells, and the lower limit of the production allocation of water wells are automatically input into the integrated simulation model. The integrated simulation model is run for optimization calculation to obtain the optimal working system of the gas wells.

2. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 1, characterized in that: The classification standards for gas wells are as follows: Pure gas well: The gas well does not produce water, that is, the water-gas ratio is less than 2m 3 / 10 4 m 3 , and more than one well spacing away from the water invasion front; Wells with water risk: gas wells that do not produce water but are within one well spacing from the water invasion front; Water well: Water has been seen in the gas well, that is, the water-gas ratio is greater than 2m 3 / 10 4 m 3 .

3. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 1 is characterized in that: The method for determining the upper and lower limits of the production allocation of the pure gas well comprises the following steps: Step a. Take the production dynamic data of pure gas wells in the past year, and divide the production history dynamic data of pure gas wells in the past year into n stages according to the division criteria that the working system of the gas wells does not change and the daily gas production is stable; Step b. Calculate the gas production per unit wellhead pressure drop at each stage; Step c. Regression gas well daily gas production and gas production per unit wellhead pressure drop correlation formula; Step d. Applying the gas well model to simulate the relationship between the daily gas production of the gas well and the wellhead pressure; Step e. Calculate the remaining recoverable reserves by calculating the wellhead pressure and gas production per unit wellhead pressure drop; Step f. According to step e, draw a relationship curve between daily gas production and remaining recoverable reserves, take the daily gas production with the maximum remaining recoverable reserves as the optimal production allocation value, determine the optimal production allocation area, the minimum daily gas production in the area is the lower limit of production allocation, and the maximum daily gas production in the area is the upper limit of production allocation.

4. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 3 is characterized in that: In step a, the daily gas production stability as the division standard means that the maximum value of the stage minus the minimum value of the stage divided by the average value of the stage is less than 5%: （1）， In the formula, : Maximum daily gas production in the stage; : Minimum daily gas production in the stage; : Average daily gas production in the stage.

5. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 4 is characterized in that: In step b, according to the divided stages, the gas production per unit wellhead pressure drop of n stages is calculated respectively, and the gas production per unit wellhead pressure drop of each stage is calculated by dividing the cumulative gas production of each stage by the wellhead pressure drop of each stage. : （2）， Where: : Cumulative gas production at the end of the stage; : Cumulative gas production at the initial stage; : wellhead pressure at the end of the stage; : Wellhead pressure at the initial stage.

6. A method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 5, characterized in that: In step c, the method for regressing the correlation between the daily gas production of the gas well and the gas production per unit wellhead pressure drop is: using Excel software to calculate the daily gas production of the gas well at each stage and gas production per unit wellhead pressure drop Perform a correlation regression: （3）， Where: a : Linear regression coefficient, representing the slope; b linear regression coefficient, representing the intercept.

7. A method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 6, characterized in that: In step d, the gas well model is used to calculate the daily gas production according to the node analysis method. Wellhead pressure relation: （4）。 8. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 7 is characterized in that: In step e, the wellhead pressure and gas production per unit wellhead pressure drop Calculate remaining recoverable reserves : （5）。 9. A method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 8, characterized in that: In step f, according to formula (5) in step e, a relationship curve between daily gas production and remaining recoverable reserves is drawn, and the daily gas production of the maximum remaining recoverable reserves is taken as the optimal production allocation value. The area between 98% of the maximum remaining recoverable reserves and the maximum remaining recoverable reserves is determined as the optimal production allocation area, the minimum daily gas production in the area is the lower limit of the production allocation, and the maximum daily gas production in the area is the upper limit of the production allocation.

10. The method for automatically determining a reasonable working system of a gas well in an intelligent gas field according to claim 1, characterized in that: The upper limit of the production allocation of the water-risk well is the production corresponding to the upper limit of the production pressure difference set for the water-risk well; the lower limit of the production allocation of the water-risk gas well is the critical production of the gas well.

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