Method and device for predicting single well productivity of target gas storage

Abstract

The invention provides a target gas storage single well productivity prediction method and device, and the method comprises the steps: obtaining the single well productivity test well production data of a target gas storage, and obtaining the average gas injection and production amount of a production stage; calculating the flowing bottomhole pressure of the gas well corresponding to each production data point by utilizing preset gas component analysis data, oil pipe parameters and a preset wellbore pipe flow equation; and calculating the average gas well open-flow capacity in the injection-production stage by using the average formation pressure in the current time period, the gas production well daily gas production rate of each production data point, the gas well bottom hole flow pressure and a preset one-point method open-flow capacity formula. On the basis of the injection-production two-way process, an open-flow capacity formula for the gas storage is established; and combining the exponential open-flow capacity equation set and the exponential productivity equation set to obtain an exponential productivity equation of a single well to predict the productivity of the single well of the target gas storage. According to the method, derivation of the single-well productivity equation is simplified, the single-well productivity equation is accurately derived with fewer production data points, and single-well productivity prediction can be rapidly implemented.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas underground storage and gas reservoir engineering, and in particular relates to a method and device for predicting the single well production capacity of a target gas storage reservoir. Background Art

[0002] As the main tool for natural gas storage, peak load regulation and supply guarantee, underground natural gas storage is an important means to ensure the safety of national gas supply. In the process of gas storage construction, predicting the production capacity of gas wells and analyzing the dynamics of gas wells are the basis for scientifically designing the operating parameters of gas storage. However, the high and low pressures of gas storage vary greatly during operation. As the formation pressure changes, the reservoir permeability and gas physical properties will also change. If the same production capacity equation is used to calculate the injection and production capacity of gas wells, it will lead to certain errors.

[0003] At present, the production capacity equations of single wells in different injection and production stages of underground gas storage are basically obtained through actual production capacity tests. The relevant data are sorted and analyzed to get the corresponding single well production capacity equations. Each test process will affect the opening efficiency of the injection and production wells of the gas storage, and in the process of testing, it is easy to cause falling objects in the well, which will seriously hinder the injection and production capacity of the single well. Summary of the invention

[0004] In order to enrich the prediction method of the single well productivity of the target gas storage reservoir, the present invention proposes a prediction method of the single well productivity of the target gas storage reservoir, comprising the following steps:

[0005] Obtain the production data of the single well capacity test of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage, wherein the production data at least includes the average formation pressure in the current time period and the daily gas production volume of the gas production well at each production data point;

[0006] Using the preset gas component analysis data, tubing parameters and the preset wellbore flow equation, the bottom hole flow pressure of the gas well corresponding to each production data point is obtained;

[0007] The open flow rate of the gas well corresponding to each production data point is obtained by using the average formation pressure of the current time period, the daily gas production of the gas well at each production data point, the bottom hole flowing pressure of the gas well corresponding to each production data point and the preset open flow rate formula of the one-point method, and the average open flow rate of the gas well in the injection and production stage is calculated;

[0008] Substituting the average open-flow rate of the gas well in the injection-production stage and the average formation pressure in the current time period into a preset exponential open-flow rate equation group for the injection stage;

[0009] The bottom hole flowing pressure corresponding to each production point is used to calculate the average bottom hole flowing pressure of a single well in the injection and production stage, and the average bottom hole flowing pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period are substituted into a preset exponential production capacity equation group;

[0010] The exponential unimpeded flow equations and exponential production capacity equations in the injection phase with values ​​are combined to obtain the exponential production capacity equation of a single well, which is used to predict the production capacity of a single well in the target gas storage reservoir.

[0011] Furthermore, the acquisition of the single well productivity test production data of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage includes:

[0012] Select several existing production data points according to preset rules;

[0013] Sum the daily gas production of the gas wells at each production data point to obtain the total daily gas production of the gas wells;

[0014] The average gas injection and production volume during the production phase is obtained by dividing the daily gas production of the total gas production wells by the number of production data points.

[0015] Furthermore, the preset wellbore flow equation is:

[0016]

[0017] Where P wf is the bottom hole flowing pressure of the gas well corresponding to each production data point, MPa; P tf is the wellhead pressure, MPa; f is the friction coefficient; q is the daily gas production of the gas well, m 3 / d; is the average temperature of the gas in the column, K; is the average deviation coefficient of wellbore gas, dimensionless; D is the inner diameter of the oil pipe, mm; r g is the relative density of natural gas, H is the depth from the wellhead to the middle of the gas layer, and s is the equation index.

[0018] Furthermore, the preset exponential open-flow flow equations in the injection stage include:

[0019] Gas production stage:

[0020] Gas injection phase:

[0021] in, is the average open-flow rate during the injection-production period, P e is the average formation pressure in the current time period, P max is the preset upper limit operating pressure of the gas storage reservoir during the gas injection phase. is the average formation pressure corresponding to the upper limit operating pressure of the gas reservoir, and C and a are the coefficients to be solved.

[0022] Furthermore, the bottom hole flowing pressure corresponding to each production point is used to calculate the average bottom hole flowing pressure of a single well in the injection-production stage, including:

[0023] Sum the bottom hole flowing pressures corresponding to the production points to obtain the total bottom hole flowing pressure;

[0024] The total bottom hole flowing pressure is divided by the number of production data points to obtain the average bottom hole flowing pressure of a single well during the injection and production stage.

[0025] Furthermore, the preset exponential capacity equation group includes:

[0026] Gas production stage:

[0027] Gas injection phase:

[0028] in, is the average gas injection and production volume in the production stage, P e is the average formation pressure in the current time period, is the average bottom hole flowing pressure of a single well during the injection-production stage, and C and a are the coefficients to be solved.

[0029] Furthermore, the exponential unimpeded flow equation group and the exponential production capacity equation group of the combined injection stage with values ​​are used to obtain the exponential production capacity equation of a single well, including:

[0030] Combine the exponential open-flow flow equations and exponential capacity equations in the injection phase with values ​​to obtain coefficients C and a;

[0031] The exponential production capacity equation of a single well is established using the obtained coefficients C and a as follows:

[0032] I g =C(P 2 wf -P 2 e ) a

[0033] Among them, I g is the single well production capacity of the target gas storage, P wf is the bottom hole flowing pressure of the gas well corresponding to each production data point, P e is the average formation pressure during the current time period.

[0034] On the other hand, the present invention also discloses a device for predicting the production capacity of a single well of a target gas storage reservoir, comprising:

[0035] A data acquisition module is used to acquire the production data of the single well capacity test of the target gas storage reservoir, and obtain the average gas injection and production volume in the production stage. The production data at least includes the average formation pressure in the current time period and the daily gas production of the gas production well at each production data point;

[0036] The first parameter calculation module is used to obtain the bottom hole flow pressure of the gas well corresponding to each production data point by using the preset gas component analysis data, oil pipe parameters and the preset wellbore pipe flow equation;

[0037] The second parameter calculation module is used to obtain the open flow rate of the gas well corresponding to each production data point by using the average formation pressure of the current time period, the daily gas production of the gas well at each production data point, the bottom hole flowing pressure of the gas well corresponding to each production data point and a preset one-point method open flow formula, and calculate the average open flow rate of the gas well in the injection and production stage;

[0038] A first equation group calculation module is used to substitute the average open-flow rate of the gas well in the injection and production stage and the average formation pressure in the current time period into a preset exponential open-flow rate equation group for the injection stage;

[0039] The second equation group calculation module is used to calculate the average bottom hole flowing pressure of a single well in the injection and production stage by using the bottom hole flowing pressure corresponding to each production point, and substitute the average bottom hole flowing pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period into a preset exponential production capacity equation group;

[0040] The module for generating the exponential production capacity equation of a single well is used to combine the exponential unimpeded flow equation group and the exponential production capacity equation group of the injection phase with values ​​to obtain the exponential production capacity equation of a single well, so as to predict the production capacity of a single well of a target gas storage reservoir.

[0041] Obtain the production data of the single well capacity test of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage, wherein the production data at least includes the average formation pressure in the current time period and the daily gas production volume of the gas production well at each production data point;

[0042] Using the preset gas component analysis data, tubing parameters and the preset wellbore flow equation, the bottom hole flow pressure of the gas well corresponding to each production data point is obtained;

[0043] By using the average formation pressure in the current time period, the daily gas production of the gas well at each production data point, the bottom hole flowing pressure of the gas well corresponding to each production data point and the preset one-point method unobstructed flow formula, the unobstructed flow of the gas well corresponding to each production data point is obtained, and the average unobstructed flow of the gas well in the injection and production stage is calculated.

[0044] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0045] The present invention discloses at least a method for predicting the production capacity of a single well of a target gas storage reservoir, which obtains the production data of the production capacity test well of a single well of the target gas storage reservoir, and obtains the average injection and production gas volume in the production stage; uses the preset gas component analysis data, oil pipe parameters and the preset wellbore pipe flow equation to obtain the bottom hole flow pressure of the gas well corresponding to each production data point; then uses the average formation pressure of the current time period, the daily gas production of the gas production well at each production data point, the bottom hole flow pressure of the gas well corresponding to each production data point and the preset one-point method open-flow formula to obtain the open-flow flow of the gas well corresponding to each production data point, and calculates the average open-flow flow of the gas well in the injection and production stage. On the basis of considering the two-way process of injection and production, the relationship between formation pressure and open-flow is derived, and an open-flow formula for the gas storage reservoir is established; then the exponential open-flow equation group and the exponential production capacity equation group are combined to obtain the exponential production capacity equation of a single well to predict the single well production capacity of the target gas storage reservoir.

[0046] The present invention simplifies the derivation steps of the single well productivity equation, accurately derives the single well productivity equation with fewer production data points, can quickly implement the single well productivity, and reasonably guide the reasonable allocation of production and injection of single wells. The present invention can not only reduce the frequency of single well testing in gas storage reservoirs and save investment, but also reduce the damage to single wells caused by frequent testing operations, optimize the deployment of gas injection and production plans, ensure the safety of gas storages, and provide good technical support. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0048] Figure 1 This is a schematic flow chart of a method for predicting the single well production capacity of a target gas storage reservoir in Embodiment 1 of the present invention;

[0049] Figure 2 This is a flow chart of step S110 in the first embodiment of the present invention;

[0050] Figure 3 This is a schematic diagram of the structure of a device for predicting the single well production capacity of a target gas storage reservoir in the second embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0052] Embodiment 1

[0053] A method for predicting the production capacity of a single well in a target gas storage reservoir, combined with Figure 1 As shown, steps S110-S140 are included, specifically:

[0054] Step S110, obtaining the single well capacity test production data of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage, wherein the production data at least includes the average formation pressure in the current time period and the daily gas production of the gas production well at each production data point.

[0055] like Figure 2 As shown, this step includes sub-steps S111-S113:

[0056] Step S111, selecting a number of existing production data points according to a preset rule.

[0057] The data points to be measured need to be stable formation pressure and stable flow pressure under a working system, which are selected based on the existing logging data points of the actual single well. In order to predict the production capacity of a single well in the target gas storage reservoir, 5 to 8 data points are usually selected for calculation in actual projects. If there are too few data points, the relative error will be large.

[0058] Step S112, summing up the daily gas production of the gas production wells at each production data point to obtain the total daily gas production of the gas production wells.

[0059] Step S113, dividing the total daily gas production of the gas production wells by the number of production data points to obtain the average injection and production gas volume in the production stage.

[0060] In some embodiments, the actual injection and production data of the corresponding time period of the injection and production phase are selected based on the production data of the well test in the gas storage construction area. The first, second, ...n production data points can be recorded as: (P e ,q 1 )、(P e ,q 2 )…(P e ,q n ); and the average gas injection and production volume in this production stage is

[0061]

[0062] in, is the average gas injection and production volume during the production phase, 10 4 m 3 / d.P e is the average formation pressure in the current time period; q 1 ,q 2 …q n is the daily gas production of the gas wells at the 1st, 2nd, ..., nth production data points, 10 4 m 3 / d.

[0063] Step S120, using the preset gas component analysis data, tubing parameters and the preset wellbore flow equation, the bottom hole flow pressure of the gas well corresponding to each production data point is obtained.

[0064] Gas component analysis data may include: natural gas relative density, methane content, nitrogen content, hydrogen sulfide content, etc.

[0065] The tubing parameters may include: tubing inner diameter, tubing insertion depth, etc.

[0066] The preset wellbore flow equation is:

[0067]

[0068] Where: P wf is the bottom hole flowing pressure, MPa; P tf is the measured wellhead pressure, MPa; f is the friction coefficient constant; q is the daily gas production of the gas well, m 3 / d; is the average temperature of the gas in the column, K; is the average deviation coefficient of wellbore gas, dimensionless; D is the inner diameter of the tubing, mm; s is the equation index. g is the relative density of natural gas, and H is the measured depth from the wellhead to the middle of the gas layer.

[0069] The equation index s can be obtained by the following formula:

[0070]

[0071] The average temperature of the gas in the pipe string is the average of the wellhead temperature and the bottom hole temperature. The wellhead temperature and the bottom hole temperature are obtained through actual measurement. The deviation coefficient is calculated based on the pressure, temperature, hydrogen sulfide content, nitrogen content, carbon dioxide, etc. at different time points.

[0072] Step S130, using the average formation pressure of the current time period, the daily gas production of the gas wells at each production data point, the bottom hole pressure of the gas wells corresponding to each production data point and the preset one-point method open-flow formula, obtain the open-flow rate of the gas wells corresponding to each production data point, and calculate the average open-flow rate of the gas wells in the injection and production stage.

[0073] Specifically, according to the Chen Yuanqian one-point method open-flow formula, the current average formation pressure P e , daily gas production of gas wells at each production data point q i , (i=1, 2, ... n), and the bottom hole flow pressure P corresponding to each production point obtained in step S120 wf Substitute into the calculation to obtain the gas well open flow rate q at the current formation pressure at each production data pointAOF , and calculate the average gas well open flow rate of n production data points in the injection and production stage

[0074] Chen Yuanqian's one-point method unobstructed flow formula:

[0075]

[0076] Among them, q AOF is the unobstructed flow rate of the gas well, 10 4 m 3 / d;q g is the gas production of the gas well, 10 4 m 3 / d;P e is the formation pressure at the current stage, MPa.

[0077] Step S140, substituting the average open-flow rate of the gas well in the injection-production stage and the average formation pressure in the current time period into a preset exponential open-flow rate equation group for the injection stage.

[0078] Specifically, the inventors reversed the traditional process, considered the two-way process of injection and production, and established an open-flow flow formula for gas storage. According to the differences between the injection stage and the gas production stage, the exponential open-flow flow formula is divided into:

[0079] Gas production stage:

[0080] Gas injection phase:

[0081] in, is the average open-flow rate during the injection-production period, P e is the average formation pressure P in the current time period (gas production stage) max The preset upper limit operating pressure of the gas storage reservoir during the gas injection phase is the maximum gas injection pressure designed during the gas storage reservoir design. is the average formation pressure corresponding to the upper limit operating pressure of the gas reservoir, and C and a are the coefficients to be solved.

[0082] Step S150, using the bottom hole flow pressure corresponding to each production point, calculate the average bottom hole flow pressure of a single well in the injection and production stage, and use the average bottom hole flow pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period to substitute into a preset exponential production capacity equation group.

[0083] The bottom hole flowing pressures corresponding to each production point in step S120 can be summed to obtain the total bottom hole flowing pressure; then the total bottom hole flowing pressure is divided by the number of production data points to obtain the average bottom hole flowing pressure of a single well in the injection and production stage. That is:

[0084]

[0085] P wf1 , P wf2 ...P wfn are the bottom hole flowing pressure corresponding to each production point, is the average bottom hole flowing pressure of a single well during the injection and production stage, and n is the number of production data points.

[0086] Depending on the gas injection stage and gas production stage, the exponential production equation includes:

[0087] Gas production stage:

[0088] Gas injection phase:

[0089] in, is the average gas injection and production volume in the production stage, P e is the average formation pressure of the current time period. For the gas production stage, the average formation pressure of the gas production stage is used. For the gas injection stage, the average formation pressure of the gas injection stage is used. is the average bottom hole flowing pressure of a single well during the injection-production stage, and C and a are the coefficients to be solved.

[0090] Step S160, combining the exponential open-flow flow equations and the exponential production capacity equations in the injection phase with values ​​to obtain the exponential production capacity equation of a single well, so as to predict the production capacity of a single well in the target gas storage reservoir.

[0091] The exponential open-flow flow equations for the injection phase with values ​​(the result of step S140) and the exponential production capacity equations (the result of step S150) are combined to obtain coefficients C and a. The exponential production capacity equation for a single well is established using the obtained coefficients C and a as follows:

[0092] I g =C(P 2 wf -P 2 e ) a

[0093] Among them, I g is the single well production capacity of the target gas storage, P wf is the bottom hole flowing pressure of the gas well corresponding to each production data point, P e is the average formation pressure during the current time period.

[0094] For ease of understanding, the present invention specifically introduces the implementation process of the present invention by obtaining well test data of a gas storage reservoir. Table 1 shows the production capacity data of two wells (respectively marked as S1-9 and S1-16) measured for several consecutive days in a certain year, and uses step S120 to obtain the bottom hole flow pressure of the gas well corresponding to each production data point.

[0095] Table 1

[0096]

[0097]

[0098] By using steps S130-S160, the unimpeded flow rate q in the injection-production time period corresponding to the production capacity data measured in Table 1 can be obtained. AOF , The upper limit operating pressure of the gas storage during the gas injection phase P max , the average formation pressure corresponding to the upper limit operating pressure of the gas reservoir The coefficients C and a to be solved are shown in Table 2.

[0099] Table 2

[0100]

[0101] According to the data in Table 2, combined with the exponential production capacity equation of a single well in step S160, the gas injection equations of the two wells can be obtained as follows:

[0102] Well S1-9:I g =20.5627(P 2 wf -P 2 e ) 0.1368

[0103] Well S1-6:I g =6.2160(P 2 wf -P 2 e ) 0.2820

[0104] The gas injection equation of the original design of the gas storage is: g =0.8198(P 2 wf -P 2 e ) 0.5769

[0105] The production capacity equation obtained by the system well test is compared with the gas injection equation of the scheme design. The initial formation pressure of the gas storage reservoir in a certain year is 22.8MPa, and the formation pressure at the end of the gas injection in that year is predicted to be 26.7MPa. The maximum gas injection capacity of a single well when the bottom hole flow pressure reaches 42MPa is calculated by using the scheme design, system well test and the derived gas injection equation, and the reasonable gas injection capacity of a single well is predicted based on its gas injection pressure difference. It can be seen from Table 3 that the gas injection capacity calculated by the gas injection equation derived from the current production data of S1-6 and 1-9 wells is greater than the design value, indicating that the scheme of the present invention has a good effect.

[0106] Table 3

[0107]

[0108] The present invention obtains the production data of the single well capacity test of the target gas storage reservoir, and obtains the average injection and production gas volume in the production stage; uses the preset gas component analysis data, oil pipe parameters and the preset wellbore pipe flow equation to obtain the bottom hole flow pressure of the gas well corresponding to each production data point; then uses the average formation pressure of the current time period, the daily gas production of the gas production well at each production data point, the bottom hole flow pressure of the gas well corresponding to each production data point and the preset one-point method open-flow formula to obtain the open-flow flow of the gas well corresponding to each production data point, and calculates the average open-flow flow of the gas well in the injection and production stage. On the basis of considering the two-way process of injection and production, the relationship between formation pressure and open-flow is derived, and the open-flow formula for the gas storage reservoir is established; then the exponential open-flow equation group and the exponential capacity equation group are combined to obtain the exponential capacity equation of a single well to predict the single well capacity of the target gas storage reservoir.

[0109] The present invention simplifies the derivation steps of the single well production capacity equation, accurately derives the single well production capacity equation with fewer production data points, can quickly implement the single well production capacity, and reasonably guide the reasonable allocation of production and injection of single wells. The present invention can not only reduce the frequency of single well testing in gas storage reservoirs and save investment, but also reduce the damage to single wells caused by frequent testing operations, optimize the deployment of injection and production gas schemes, ensure the safety of gas reservoirs, and provide good technical support. With the help of this method, the actual injection and production data of a single well in each injection and production cycle are comprehensively analyzed to obtain the production capacity equation of a single well in the gas reservoir. Using this technical solution, 150,000 to 200,000 yuan can be saved per well.

[0110] Embodiment 2

[0111] like Figure 3 As shown, corresponding to the first embodiment, the embodiment of the present invention further discloses a prediction device for the single well production capacity of a target gas storage reservoir, comprising a data acquisition module 10, a first parameter calculation module 20, a second parameter calculation module 30, a first equation group calculation module 40, a second equation group calculation module 50, and a single well exponential production capacity equation generation module 60, wherein:

[0112] The data acquisition module 10 is used to obtain the production data of the single well capacity test of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage. The production data at least includes the average formation pressure in the current time period and the daily gas production of the gas well at each production data point.

[0113] In some embodiments, the actual injection and production data of the corresponding time period of the injection and production phase are selected based on the production data of the well test in the gas storage construction area. The first, second, ...n production data points can be recorded as: (P e ,q 1 )、(P e ,q 2 )…(P e ,q n ); and the average gas injection and production volume in this production stage is

[0114]

[0115] in, is the average gas injection and production volume during the production phase, 10 4 m 3 / d.P e is the average formation pressure in the current time period; q 1 ,q 2 …q n is the daily gas production of the gas wells at the 1st, 2nd, ..., nth production data points, 10 4 m 3 / d.

[0116] The first parameter calculation module 20 is used to obtain the bottom hole flow pressure of the gas well corresponding to each production data point by using the preset gas component analysis data, oil pipe parameters and the preset wellbore pipe flow equation.

[0117] The preset wellbore flow equation is:

[0118]

[0119] Where: P wf is the bottom hole flowing pressure, MPa; P tf is the measured wellhead pressure, MPa; f is the friction coefficient constant; q is the daily gas production of the gas well, m 3 / d; is the average temperature of the gas in the column, K; is the average deviation coefficient of wellbore gas, dimensionless; D is the inner diameter of the tubing, mm; s is the equation index. g is the relative density of natural gas, and H is the measured depth from the wellhead to the middle of the gas layer.

[0120] The equation index s can be obtained by the following formula:

[0121]

[0122] The average temperature of the gas in the pipe string is the average of the wellhead temperature and the bottom hole temperature. The wellhead temperature and the bottom hole temperature are obtained through actual measurement. The deviation coefficient is calculated based on the pressure, temperature, hydrogen sulfide content, nitrogen content, carbon dioxide, etc. at different time points.

[0123] The second parameter calculation module 30 is used to use the average formation pressure in the current time period, the daily gas production of the gas well at each production data point, the bottom hole flow pressure of the gas well corresponding to each production data point and the preset one-point method open-flow formula to obtain the open-flow rate of the gas well corresponding to each production data point, and calculate the average open-flow rate of the gas well in the injection and production stage.

[0124] According to the Chen Yuanqian one-point method open-flow formula, the current average formation pressure P e , daily gas production of gas wells at each production data point q i , (i = 1, 2, ... n), and the bottom hole pressure P corresponding to each production point wf Substitute into the calculation to obtain the gas well open flow rate q at the current formation pressure at each production data point AOF , and calculate the average gas well open flow rate of n production data points in the injection and production stage

[0125] Chen Yuanqian's one-point method unobstructed flow formula:

[0126]

[0127] Among them, q AOF is the unobstructed flow rate of the gas well, 10 4 m 3 / d;q g is the gas production of the gas well, 10 4 m 3 / d;P e is the current formation pressure, MPa.

[0128] The first equation group calculation module 40 is used to substitute the average open-flow rate of the gas well in the injection and production stage and the average formation pressure in the current time period into the preset exponential open-flow rate equation group in the injection stage.

[0129] Specifically, the inventors reversed the traditional process, considered the two-way process of injection and production, and established an open-flow flow formula for gas storage. According to the differences between the injection stage and the gas production stage, the exponential open-flow flow formula is divided into:

[0130] Gas production stage:

[0131] Gas injection phase:

[0132] in, is the average open-flow rate during the injection-production period, P e is the average formation pressure during the gas production stage. For the gas production stage, the average formation pressure during the gas production stage is used. For the gas injection stage, the average formation pressure during the gas injection stage is used. P max is the preset upper limit operating pressure of the gas storage reservoir during the gas injection phase. is the average formation pressure corresponding to the upper limit operating pressure of the gas reservoir, and C and a are the coefficients to be solved.

[0133] The second equation group calculation module 50 is used to calculate the average bottom hole flowing pressure of a single well in the injection and production stage using the bottom hole flowing pressure corresponding to each production point, and to substitute the average bottom hole flowing pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period into the preset exponential production capacity equation group.

[0134] The bottom hole flowing pressure corresponding to each production point is summed to obtain the total bottom hole flowing pressure; then the total bottom hole flowing pressure is divided by the number of production data points to obtain the average bottom hole flowing pressure of a single well in the injection and production stage. That is:

[0135]

[0136] P wf1 , P wf2 ...P wfn are the bottom hole flowing pressure corresponding to each production point, is the average bottom hole flowing pressure of a single well during the injection and production stage, and n is the number of production data points.

[0137] Depending on the gas injection stage and gas production stage, the exponential production equation includes:

[0138] Gas production stage:

[0139] Gas injection phase:

[0140] in, is the average gas injection and production volume in the production stage, P e is the average formation pressure in the current time period, is the average bottom hole flowing pressure of a single well during the injection-production stage, and C and a are the coefficients to be solved.

[0141] The single well exponential production capacity equation generation module 60 is used to combine the injection phase exponential unimpeded flow equation group and the exponential production capacity equation group containing values ​​to obtain the single well exponential production capacity equation for predicting the single well production capacity of the target gas storage reservoir.

[0142] The exponential open-flow flow equations and exponential production capacity equations of the injection phase with values ​​are combined to obtain coefficients C and a. The exponential production capacity equation of a single well is established using the obtained coefficients C and a as follows:

[0143] I g =C(P 2 wf -P 2 e ) a

[0144] Among them, I g is the single well production capacity of the target gas storage, P wf is the bottom hole flowing pressure of the gas well corresponding to each production data point, P e is the average formation pressure during the current time period.

[0145] The specific working mode and examples of this device can be referred to in Example 1, which will not be described in detail here.

[0146] In addition, an embodiment of the present invention further discloses a computer-readable storage medium, in which instructions are stored. When the instructions are executed on a terminal, the terminal executes the method for predicting the single well production capacity of a target gas storage reservoir in the first embodiment.

[0147] An embodiment of the present invention also discloses a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method for predicting the single well production capacity of a target gas storage reservoir disclosed in Embodiment 1 is implemented.

[0148] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0149] The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is encompassed in a manner similar to the term "including", as explained by "including," used as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

1. A method for predicting the single well production capacity of a target gas storage reservoir, characterized in that: The following steps are involved: Obtain the production data of the single well capacity test of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage, wherein the production data at least includes the average formation pressure in the current time period and the daily gas production volume of the gas production well at each production data point; Using the preset gas component analysis data, tubing parameters and the preset wellbore flow equation, the bottom hole flow pressure of the gas well corresponding to each production data point is obtained; The open flow rate of the gas well corresponding to each production data point is obtained by using the average formation pressure of the current time period, the daily gas production of the gas well at each production data point, the bottom hole flowing pressure of the gas well corresponding to each production data point and the preset open flow rate formula of the one-point method, and the average open flow rate of the gas well in the injection and production stage is calculated; Substituting the average open-flow rate of the gas well in the injection-production stage and the average formation pressure in the current time period into a preset exponential open-flow rate equation group for the injection stage; The bottom hole flowing pressure corresponding to each production point is used to calculate the average bottom hole flowing pressure of a single well in the injection and production stage, and the average bottom hole flowing pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period are substituted into a preset exponential production capacity equation group; The exponential unimpeded flow equations and exponential production capacity equations in the injection phase with values ​​are combined to obtain the exponential production capacity equation of a single well, which is used to predict the production capacity of a single well in the target gas storage reservoir.

2. The prediction method according to claim 1, characterized in that: The method of obtaining the production data of a single well of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage includes: Select several existing production data points according to preset rules; Sum the daily gas production of the gas wells at each production data point to obtain the total daily gas production of the gas wells; The average gas injection and production volume during the production phase is obtained by dividing the daily gas production of the total gas production wells by the number of production data points.

3. The prediction method according to claim 1, characterized in that: The preset wellbore flow equation is: Where P wf is the bottom hole flowing pressure, MPa; P tf is the measured wellhead pressure, MPa; f is the friction coefficient constant; q is the daily gas production of the gas well, m 3 / d; is the average temperature of the gas in the column, K; is the average deviation coefficient of wellbore gas, dimensionless; D is the inner diameter of the tubing, mm; s is the equation index, r g is the relative density of natural gas, and H is the measured depth from the wellhead to the middle of the gas layer.

4. The prediction method according to claim 1, characterized in that: The preset exponential open-flow flow equations for the injection stage include: Gas production stage: Gas injection phase: in, is the average open-flow rate during the injection-production period, P e is the average formation pressure in the current time period, P max is the preset upper limit operating pressure of the gas storage reservoir during the gas injection phase. is the average formation pressure corresponding to the upper limit operating pressure of the gas reservoir, and C and a are the coefficients to be solved.

5. The prediction method according to claim 1, characterized in that: Using the bottom hole flowing pressure corresponding to each production point, the average bottom hole flowing pressure of a single well in the injection and production stage is calculated, including: Sum the bottom hole flowing pressures corresponding to the production points to obtain the total bottom hole flowing pressure; The total bottom hole flowing pressure is divided by the number of production data points to obtain the average bottom hole flowing pressure of a single well during the injection and production stage.

6. The prediction method according to claim 1, characterized in that: The preset exponential capacity equation group includes: Gas production stage: Gas injection phase: in, is the average gas injection and production volume in the production stage, P e is the average formation pressure in the current time period, is the average bottom hole flowing pressure of a single well during the injection-production stage, and C and a are the coefficients to be solved.

7. The prediction method according to claim 1, characterized in that: The exponential unimpeded flow equation group and the exponential productivity equation group of the injection stage with combined values ​​are used to obtain the exponential productivity equation of a single well, including: Combine the exponential open-flow flow equations and exponential capacity equations in the injection phase with values ​​to obtain coefficients C and a; The exponential production capacity equation of a single well is established using the obtained coefficients C and a as follows: I g =C(P 2 wf -P 2 e ) a Among them, I g is the single well production capacity of the target gas storage, P wf is the bottom hole flowing pressure of the gas well corresponding to each production data point, P e is the average formation pressure during the current time period.

8. A device for predicting the production capacity of a single well of a target gas storage reservoir, characterized in that: It includes a data acquisition module, a first parameter calculation module, a second parameter calculation module, a first equation group calculation module, a second equation group calculation module, and a single well exponential production capacity equation generation module, wherein: The data acquisition module is used to obtain the production data of the single well capacity test of the target gas storage reservoir to obtain the average gas injection and production volume in the production stage, wherein the production data at least includes the average formation pressure in the current time period and the daily gas production of the gas production well at each production data point; The first parameter calculation module is used to obtain the bottom hole flow pressure of the gas well corresponding to each production data point by using the preset gas component analysis data, oil pipe parameters and the preset wellbore pipe flow equation; The second parameter calculation module is used to obtain the open flow rate of the gas well corresponding to each production data point by using the average formation pressure of the current time period, the daily gas production of the gas well at each production data point, the bottom hole flowing pressure of the gas well corresponding to each production data point and a preset one-point method open flow formula, and calculate the average open flow rate of the gas well in the injection and production stage; The first equation group calculation module is used to substitute the average open-flow rate of the gas well in the injection and production stage and the average formation pressure in the current time period into a preset exponential open-flow rate equation group for the injection stage; The second equation group calculation module is used to calculate the average bottom hole flowing pressure of a single well in the injection and production stage by using the bottom hole flowing pressure corresponding to each production point, and substitute the average bottom hole flowing pressure of a single well in the injection and production stage, the average injection and production gas volume in the production stage, and the average formation pressure in the current time period into a preset exponential production capacity equation group; The single well exponential production capacity equation generation module is used to combine the injection phase exponential unimpeded flow equation group and the exponential production capacity equation group containing values ​​to obtain the single well exponential production capacity equation for predicting the single well production capacity of the target gas storage reservoir.

9. A computer-readable storage medium, wherein instructions are stored in the computer-readable storage medium. When the instructions are executed on a terminal, the terminal executes the method for predicting the single-well production capacity of a target gas storage reservoir as described in any one of claims 1 to 7.

10. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for predicting the single well production capacity of a target gas storage reservoir as described in any one of claims 1 to 7 when executing the computer program.

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