Gas storage injection-production capacity analysis method

Abstract

The invention discloses a gas storage injection-production capacity analysis method, which comprises the following steps of: establishing a binomial productivity equation for an injection-production well of which productivity well testing data is obtained; for a well which only obtains a one-point method productivity test, a binomial productivity equation is established through approximate regression by using a stable test point (qg, pwf) and a calculated open-flow capacity point (qAOF, 0.1). And combining with the well body structure of the injection-production well, making an injection-production capacity analysis chart of the injection-production well at different injection-production stages and under different formation pressures through node analysis, and evaluating the matching relationship between the reservoir seepage capacity and the well shaft through the chart to obtain the injection-production gas quantity of the injection-production well under different formation pressures, well bottom pressures and well mouth pressures. Meanwhile, the influence of gas flow erosion on the oil pipe in the injection-production process of the injection-production well is considered, an oil pipe injection-production anti-erosion capacity analysis chart of the injection-production well under different formation pressures is formed, and technical support is provided for evaluating the injection-production capacity of a gas storage and optimizing deployment of the injection-production well.

Description

Technical Field

[0001] This invention relates to the field of gas storage injection and production capacity, and in particular to a method for analyzing the injection and production capacity of gas storage facilities. Background Technology

[0002] Currently, both domestically and internationally, the main methods for determining the injection and production capacity of gas storage injection and production wells are nodal analysis, gas production index, or analogy. However, existing technologies present the following problems in determining the injection and production capacity of gas storage facilities:

[0003] 1. Currently, the traditional "one-point method" is commonly used to calculate the open flow rate of gas wells. However, in this method, α is usually an empirical average. Theoretically, calculating the binomial open flow rate of a gas well requires determining the Darcy flow coefficient A and the non-Darcy flow coefficient B, and at least three effective stable operating conditions for test pressure and flow rate. The test results from one operating condition are insufficient to establish a production capacity equation. Because... When similar gas reservoirs are similar, the α value reflects their characteristics to some extent, making it possible to calculate the unobstructed flow rate using traditional single-point steady-state flow test parameters. However, since the α value reflects the characteristics of the gas reservoir, different gas reservoirs should have different α values. Therefore, it is inaccurate to calculate the unobstructed flow rate of all gas reservoirs by taking the empirical average value of α, which will introduce a large error into the calculation of gas storage capacity.

[0004] 2. Existing analytical methods cannot efficiently analyze the production capacity of a reservoir, nor can they efficiently analyze the gas production and injection capacity of a single well. Furthermore, they cannot efficiently assess the relationship between reservoir permeability and wellbore configuration. This results in limitations in existing analytical methods, hindering the efficient optimization of injection and production well deployment. Summary of the Invention

[0005] The purpose of this invention is to provide a method for analyzing the injection and production capacity of gas storage facilities, addressing the aforementioned shortcomings. This method establishes a binomial production capacity equation for injection and production wells for which production test data has been obtained; for wells with only a single-point production test, it utilizes a stable test point (q)... g p wf ) and the calculated unobstructed flow point (q) AOF (0.1), an approximate regression was used to establish a binomial production capacity equation. Combined with the wellbore structure of the injection and production well, an injection and production capacity analysis chart was created under different injection and production stages and different formation pressures through node analysis. This chart can be used to evaluate the relationship between reservoir permeability and wellbore, and to obtain the injection and production gas volume under different formation pressures, bottom hole pressures, and wellhead pressures of the injection and production well.

[0006] Meanwhile, considering the impact of gas flow erosion on the tubing during the injection and production process, an analysis chart of the tubing erosion resistance under different formation pressures was created, providing technical support for evaluating the gas storage injection and production capacity and optimizing the deployment of injection and production wells.

[0007] This invention is achieved through the following scheme:

[0008] A method for analyzing the injection and production capacity of a gas storage facility, comprising at least the following steps:

[0009] S1: Construct the gas extraction binomial equation and the gas injection binomial equation;

[0010] S2: Divide the gas storage into several single wells to be analyzed. Based on the historical gas injection capacity test data and gas production capacity test data of the single wells to be analyzed, substitute them into the gas production binomial equation and gas injection binomial equation in S1 to obtain the gas production binomial capacity equation and gas injection binomial capacity equation respectively.

[0011] S3: Based on the production binomial production capacity equation and injection binomial production capacity equation in S2, obtain the unobstructed flow rate of the production capacity test under a predetermined pressure; based on the unobstructed flow rate results of the production capacity test, improve the "one-point method" to obtain the different α values ​​and their average values ​​for each well to be analyzed.

[0012] S4: Based on the actual test results of the single well to be analyzed, select the binomial production capacity equation or the improved "one-point method" to obtain the range value of the single well to be analyzed in the gas storage under the predetermined pressure.

[0013] The process of constructing the binomial equation for gas extraction in S1 is as follows: During the gas extraction process, considering both the convenience of field application and the accuracy of calculation, the binomial inflow dynamic model is more suitable, and its formula is:

[0014]

[0015] In the formula: p r Formation pressure, MPa; p wf A is the bottom hole flowing pressure, MPa; A and B are binomial productivity coefficients, MPa. 2 ·d / (10 4 m 3 (mPa·s), (MPa·d) 2 / [(10 4 m 3 ) 2 ·mPa·s];q g For gas production, 10 4 m 3 / d.

[0016] The process of constructing the gas injection binomial equation in S1 is as follows:

[0017] For gas injection, if a gas injection capacity test has been conducted, the gas injection binomial productivity equation is used for calculation; if no gas injection capacity test has been conducted, it is assumed that the injection capacity and production capacity of the vertical well are the same, resulting in a formation outflow dynamic model with the bottom of the well as the node:

[0018]

[0019] In S3, the specific steps to improve the "one-point method" are as follows:

[0020] S31: Calculate the one-point unobstructed flow rate of each well under different formation pressures at different times during the gas production period;

[0021] S32: By changing the α value, the unobstructed flow rate calculated by the one-point method is matched with the unobstructed flow rate calculated by the production well test:

[0022] S33: Obtain the different α values ​​and their average values ​​for each well.

[0023] S2 may also include a method for calculating and analyzing the gas production capacity of the single well to be analyzed, specifically including:

[0024] S221: Based on the binomial gas production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas production capacity under different bottom hole pressures and the corresponding wellhead pressure, and obtain a quantitative relationship chart between bottom hole pressure, wellhead pressure and gas production:

[0025] S222: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas production in the single well to be analyzed in S221, determine the matching relationship between tubing size and reservoir permeability:

[0026] S223: The intersection diagram is obtained by drawing the gas production curve of the tubing with the critical erosion curve based on the predetermined diameter. The intersection diagram shows the reasonable gas production range of the single well to be analyzed when the formation pressure is within the predetermined range.

[0027] It also includes S224: By analyzing the gas production capacity of all the individual wells to be analyzed, the reasonable gas production range of all individual wells in the gas storage can be obtained.

[0028] S2 may also include a method for calculating and analyzing the gas injection capacity of the single well to be analyzed, specifically including:

[0029] S231: Determine whether the gas injection capacity test has been carried out for the single well to be analyzed. If yes, then based on the gas injection binomial production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressure, obtain the quantitative relationship chart between bottom hole pressure, wellhead pressure and gas injection volume, and jump to S232 for analysis. If no, then the gas injection capacity analysis adopts the gas production capacity equation; and jump to S233 for analysis.

[0030] S232: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas injection volume in the single well to be analyzed in S232, determine the matching relationship between tubing size and reservoir permeability:

[0031] S233: The intersection diagram is obtained by drawing the gas injection curve of the tubing with the predetermined diameter and the critical erosion curve. The intersection diagram shows the reasonable gas injection range of the single well to be analyzed when the predetermined formation pressure range is within the range.

[0032] S234: By analyzing the gas injection capacity of all the individual wells to be analyzed, the reasonable gas injection volume range of all individual wells in the gas storage can be obtained.

[0033] The inner diameter of the oil pipe is 100.53 mm or 157.08 mm.

[0034] During gas extraction, the dynamic model of wellbore outflow uses the vertical pipe flow pressure calculation formula:

[0035]

[0036] In the formula: p wh γ is the wellhead flow pressure, MPa; s is the pressure coefficient, dimensionless; f is the tubing friction coefficient; γ g ρ is the relative density of the gas; H is the depth of the middle of the producing layer, m; d is the inner diameter of the tubing, m; e is the absolute roughness of the tubing interior, m; R e It is the Reynolds number.

[0037] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0038] 1. In this scheme, for injection-production wells for which production test data has been obtained, a binomial production equation is established for that well; for wells for which only a single-point production test has been obtained, a stable test point (q) is used. g p wf ) and the calculated unobstructed flow point (q) AOF (0.1), an approximate regression was used to establish a binomial production capacity equation. Combined with the wellbore structure of the injection and production well, an injection and production capacity analysis chart was created under different injection and production stages and different formation pressures through node analysis. This chart can be used to evaluate the relationship between reservoir permeability and wellbore, and to obtain the injection and production gas volume under different formation pressures, bottom hole pressures, and wellhead pressures of the injection and production well.

[0039] Meanwhile, considering the impact of gas flow erosion on the tubing during the injection and production process, an analysis chart of the tubing erosion resistance under different formation pressures was created, providing technical support for evaluating the gas storage injection and production capacity and optimizing the deployment of injection and production wells. Attached Figure Description

[0040] Figure 1This is a node analysis diagram of the gas extraction conditions of this invention;

[0041] Figure 2 This is a node analysis diagram of the gas extraction conditions of this invention;

[0042] Figure 3 The measured curves of pressure, temperature and gas injection volume for the gas injection capacity test of well Xiangchu 1 are fitted with the binomial production capacity equation.

[0043] Figure 4 The measured curves of pressure, temperature and gas production rate of well Xiangchu 1 are fitted with the binomial production capacity equation.

[0044] Figure 5 The measured curves of pressure, temperature and gas injection volume for the gas injection capacity test of well Xiangchu 3 are fitted with the binomial production capacity equation.

[0045] Figure 6 The measured curves of pressure, temperature and gas production volume of well Xiangchu 3 are fitted with the binomial production capacity equation.

[0046] Figure 7 The measured curves of pressure, temperature and gas injection volume for the gas injection capacity test of well Xiangchu 7 are fitted with the binomial production capacity equation.

[0047] Figure 8 The measured curves of pressure, temperature and gas production volume of well Xiangchu 7 are fitted with the binomial production capacity equation.

[0048] Figure 9 The measured curves of pressure, temperature and gas production volume of well Xiangchu 15 are fitted with the binomial production capacity equation.

[0049] Figure 10 The measured curves of pressure, temperature and gas injection volume for the gas injection capacity test of well Xiangchu 19 are fitted with the binomial production capacity equation.

[0050] Figure 11 A chart for quantitative analysis of the gas production capacity of the Xiangchu 1 well;

[0051] Figure 12 Analysis diagram of the erosion resistance of gas production from well Xiangchu 1;

[0052] Figure 13 A chart for quantitative analysis of the gas production capacity of well Xiangchu 3;

[0053] Figure 14 Analysis diagram of the erosion resistance of gas production from well Xiangchu 3;

[0054] Figure 15 A chart for quantitative analysis of the gas production capacity of well Xiangchu 7;

[0055] Figure 16Analysis diagram of the erosion resistance of gas production in well Xiangchu 7;

[0056] Figure 17 Chart for quantitative analysis of gas production capacity of well Xiangchu 15;

[0057] Figure 18 Analysis diagram of the erosion resistance of gas production from well Xiangchu 15;

[0058] Figure 19 A chart for quantitative analysis of the gas production capacity of well Xiangchu 19;

[0059] Figure 20 This is a diagram showing the erosion resistance of a 100.53mm inner diameter oil pipe for gas production.

[0060] Figure 21 To determine the appropriate gas production rate for injection and production wells under different formation pressures in gas storage facilities;

[0061] Figure 22 A chart for quantitative analysis of the gas injection capacity of the Xiangchu 1 well;

[0062] Figure 23 Analysis diagram of the erosion resistance of gas injection in well Xiangchu 1;

[0063] Figure 24 A chart for quantitative analysis of the gas injection capacity of well Xiangchu 3;

[0064] Figure 25 Analysis diagram of the erosion resistance of gas injection in well Xiangchu 3;

[0065] Figure 26 A chart for quantitative analysis of the gas injection capacity of well Xiangchu 7;

[0066] Figure 27 Analysis diagram of the erosion resistance of gas injection in well Xiangchu 7;

[0067] Figure 28 This is a graph showing the erosion resistance of a 100.53mm inner diameter oil pipe during gas injection.

[0068] Figure 29 Analysis diagram of the erosion resistance of well Xiangchu 19;

[0069] Figure 30 To determine the appropriate gas injection volume for injection and production wells under different formation pressures at the Xiangguosi Gas Storage Facility. Detailed Implementation

[0070] All features disclosed in this specification, or all steps in all disclosed methods or processes, may be combined in any way, except for mutually exclusive features and / or steps.

[0071] Any feature disclosed in this specification (including any appended claims and abstract) may be replaced by other equivalent or similar features, unless specifically stated otherwise. That is, unless specifically stated otherwise, each feature is merely one example of a series of equivalent or similar features.

[0072] In the description of this invention, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0073] Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0074] Example 1

[0075] This invention provides a technical solution:

[0076] A method for analyzing the injection and production capacity of a gas storage facility, comprising at least the following steps:

[0077] S1: Construct the gas extraction binomial equation and the gas injection binomial equation;

[0078] S2: Divide the gas storage into several single wells to be analyzed. Based on the historical gas injection capacity test data and gas production capacity test data of the single wells to be analyzed, substitute them into the gas production binomial equation and gas injection binomial equation in S1 to obtain the gas production binomial capacity equation and gas injection binomial capacity equation respectively.

[0079] S3: Based on the production binomial production capacity equation and injection binomial production capacity equation in S2, obtain the unobstructed flow rate of the production capacity test under a predetermined pressure; based on the unobstructed flow rate results of the production capacity test, improve the "one-point method" to obtain the different α values ​​and their average values ​​for each well to be analyzed.

[0080] S4: Based on the actual test results of the single well to be analyzed, select the binomial production capacity equation or the improved "one-point method" to obtain the range value of the single well to be analyzed in the gas storage under the predetermined pressure.

[0081] The process of constructing the gas production binomial equation in S1 is as follows: The bottom of the well is typically selected as the node, and the formation flow section from the reservoir to the bottom of the well is divided into the inflow section, and the wellbore flow section from the bottom of the well to the wellhead is divided into the outflow section. By plotting the inflow and outflow dynamic curves of the gas well, the inflow and outflow coordination point of the gas well can be obtained. The production rate corresponding to this point is the maximum injection and production capacity of the gas well under these conditions. Figure 1 As shown;

[0082] During gas extraction, considering both ease of on-site application and computational accuracy, the binomial inflow dynamic model is more suitable, and its formula is:

[0083]

[0084] In the formula: p r Formation pressure, MPa; p wf A is the bottom hole flowing pressure, MPa; A and B are binomial productivity coefficients, MPa. 2 ·d / (10 4 m 3 (mPa·s), (MPa·d) 2 / [(10 4 m 3 ) 2 ·mPa·s];q g For gas production, 10 4 m 3 / d.

[0085] During gas extraction, the dynamic model of wellbore outflow uses the vertical pipe flow pressure calculation formula:

[0086]

[0087] In the formula: p wh γ is the wellhead flow pressure, MPa; s is the pressure coefficient, dimensionless; f is the tubing friction coefficient; γ g ρ is the relative density of the gas; H is the depth of the middle of the producing layer, m; d is the inner diameter of the tubing, m; e is the absolute roughness of the tubing interior, m; R e It is the Reynolds number.

[0088] The process of constructing the gas injection binomial equation in S1 is as follows:

[0089] For gas injection, if a gas injection capacity test has been conducted, the gas injection binomial productivity equation is used for calculation; if no gas injection capacity test has been conducted, it is assumed that the injection capacity and production capacity of the vertical well are the same, and a formation outflow dynamic model with the bottom of the well as the node can be obtained:

[0090]

[0091] Under injection conditions, the dynamic model of wellbore outflow uses the vertical pipe flow pressure calculation formula:

[0092]

[0093] Using nodal analysis, inflow and outflow dynamic models were established for the gas injection and production processes. Figure 2This allows for the calculation of the injection and production capacity range of gas wells under different tubing sizes, formation pressures, and wellhead pressures.

[0094] In S3, the specific steps to improve the "one-point method" are as follows:

[0095] S31: Calculate the one-point unobstructed flow rate of each well under different formation pressures at different times during the gas production period;

[0096] S32: By changing the α value, the unobstructed flow rate calculated by the one-point method is matched with the unobstructed flow rate calculated by the production well test:

[0097] S33: Obtain the different α values ​​and their average values ​​for each well.

[0098] S2 may also include a method for calculating and analyzing the gas production capacity of the single well to be analyzed, specifically including:

[0099] S221: Based on the binomial gas production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas production capacity under different bottom hole pressures and the corresponding wellhead pressure, and obtain a quantitative relationship chart between bottom hole pressure, wellhead pressure and gas production:

[0100] S222: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas production in the single well to be analyzed in S221, determine the matching relationship between tubing size and reservoir permeability:

[0101] S223: The intersection diagram is obtained by drawing the gas production curve of the tubing with the critical erosion curve based on the predetermined diameter. The intersection diagram shows the reasonable gas production range of the single well to be analyzed when the formation pressure is within the predetermined range.

[0102] S224: By analyzing the gas production capacity of all the individual wells to be analyzed, the reasonable gas production range of all individual wells in the gas storage can be obtained.

[0103] S2 may also include a method for calculating and analyzing the gas injection capacity of the single well to be analyzed, specifically including:

[0104] S231: Determine whether the gas injection capacity test has been carried out for the single well to be analyzed. If yes, then based on the gas injection binomial production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressure, obtain the quantitative relationship chart between bottom hole pressure, wellhead pressure and gas injection volume, and jump to S232 for analysis. If no, then the gas injection capacity analysis adopts the gas production capacity equation; and jump to S233 for analysis.

[0105] S232: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas injection volume in the single well to be analyzed in S232, determine the matching relationship between tubing size and reservoir permeability:

[0106] S233: The intersection diagram is obtained by drawing the gas injection curve of the tubing with the predetermined diameter and the critical erosion curve. The intersection diagram shows the reasonable gas injection range of the single well to be analyzed when the predetermined formation pressure range is within the range.

[0107] S234: By analyzing the gas injection capacity of all the individual wells to be analyzed, the reasonable gas injection volume range of all individual wells in the gas storage can be obtained.

[0108] Example 2

[0109] This embodiment introduces the traditional "one-point method":

[0110] Establishing the binomial production capacity formula requires determining two coefficients, A and B. The testing process must require at least three testing regimes to establish the relationship between pressure and output. Professor Chen Yuanqian simplified the binomial production capacity formula into a "single-point method" production capacity formula through statistics, calculating the unobstructed flow rate of gas wells using single-point stable test data.

[0111] The binomial productivity equation derived above is in the form of:

[0112]

[0113] When pwf = 0.101 MPa, equation (3-2-9) can be expressed as:

[0114]

[0115] Dividing equation (3-2-9) by equation (3-2-10), and considering that pe2-0.1012≈pe2, we have:

[0116]

[0117] make:

[0118] but:

[0119] With q g / q aof Given the unknown variable, solve the quadratic equation (3-2-12) to obtain:

[0120]

[0121] Equation (3-2-13) can be further simplified to:

[0122]

[0123] Based on the stable well test data of 16 gas wells in 16 gas fields in Sichuan, my country, the average value of α was calculated to be 0.2541. Substituting α = 0.25 into equation (3-2-14), we get:

[0124]

[0125] Equation (3-2-14), after empirically determining the value of α, can effectively utilize well completion test results to quickly evaluate gas well productivity. It is convenient for field application and is highly popular among reservoir engineers. As shown in equation (3-2-15), once the test production Q of a well is known... g Given the corresponding stable pressure, the unobstructed flow rate Q of the well can be calculated. aof .

[0126] Equation (3-2-15) is obtained when α is 0.25. If different values ​​of α are taken, different forms of the production capacity equation can be obtained.

[0127] Theoretically, calculating the binomial gas well free-flow rate requires determining the Darcy flow coefficient A and the non-Darcy flow coefficient B, necessitating test pressures and flow rates under at least three effective stable operating conditions. Test results from a single operating condition are insufficient to establish a production capacity equation. Because... When gas reservoirs of the same type are not significantly different, their flow patterns can reflect reservoir characteristics to some extent, making it possible to calculate unobstructed flow rates using a single steady-state flow test parameter. However, since the α value reflects reservoir characteristics, different reservoirs with different characteristics should have different α values. Therefore, it is inaccurate to calculate the unobstructed flow rate of all gas reservoirs using α = 0.25.

[0128] This example provides specific data from a gas storage facility within my country for illustration:

[0129] Table 3-2-2 Summary of Unobstructed Flow Rate and Test Unobstructed Flow Rate of Gas Sampling at One Point in Gas Storage Facility (28MPa)

[0130]

[0131] As shown in Table 3-2-2, the result obtained by calculating the unobstructed flow rate of the injection-production well using α=0.25 differs significantly from the unobstructed flow rate obtained from testing. Therefore, it is necessary to determine an accurate value of α or introduce other parameters to establish a corresponding "one-point method" formula for calculating the unobstructed flow rate, which will facilitate accurate and rapid evaluation of the injection-production capacity of the well.

[0132] This embodiment establishes specific injection-production well productivity equations based on multiple gas storage wells in a gas storage facility within my country:

[0133] (1) Xiangchu 1 well

[0134] Based on the gas injection production capacity test data of Xiangchu 1 well in September 2013, and the previously derived gas injection binomial equation, the gas injection binomial production capacity equation is obtained as follows:

[0135]

[0136] Specifically, such as Figure 3 As shown:

[0137] Similarly, based on the gas production capacity test data from December 2014 and the previously derived binomial equation for gas production capacity, the following equation is obtained:

[0138]

[0139] Specifically, such as Figure 4 As shown:

[0140] (2) Xiangchu 3 well

[0141] Based on the gas injection production capacity test data of Xiangchu 3 well in September 2014, and the previously derived gas injection binomial equation, the gas injection binomial production capacity equation of Xiangchu 3 well is obtained as follows:

[0142]

[0143] Specifically, such as Figure 5 As shown:

[0144] Similarly, the binomial gas production capacity equation can be obtained as follows:

[0145]

[0146] Specifically, such as Figure 6 As shown:

[0147] (3) Well Xiangchu 7

[0148] Based on the gas injection production capacity test data of well Xiangchu 7 in October 2013, the binomial gas injection production capacity equation is obtained:

[0149]

[0150] Specifically, such as Figure 7 As shown:

[0151] Similarly, based on the gas production capacity test data from December 2014 and the previously derived binomial equation for gas production capacity, the following equation is obtained:

[0152]

[0153] Specifically, such as Figure 8 As shown:

[0154] (4) Xiangchu 15 well

[0155] Based on the gas production capacity test data from December 2014, the binomial gas production capacity equation is as follows:

[0156]

[0157] Specifically, such as Figure 9 As shown:

[0158] (5) Xiangchu 19 well

[0159] Based on the gas production capacity test data of Xiangchu 19 well in December 2015, and the previously derived gas injection binomial equation, the gas production capacity equation of Xiangchu 19 well is obtained as follows:

[0160]

[0161] Specifically, such as Figure 10 As shown:

[0162] In summary, using the same method, the binomial production capacity equations and unobstructed flow rates of other gas wells in the gas storage facility that underwent production capacity testing were obtained, as shown in Table 3-2-1.

[0163] Table 3-2-1 Summary of Interpretation of Gas Storage Capacity Test Wells

[0164]

[0165]

[0166] Based on the interpretation results of the gas storage capacity test wells, the α value of the one-point method capacity formula is calculated, and the establishment process is as follows:

[0167] ① Calculate the one-point flow rate without obstruction for each well under different formation pressures at different times during the gas production period;

[0168] ② By changing the α value, the unobstructed flow rate calculated by the one-point method is matched with the unobstructed flow rate calculated by the production capacity test;

[0169] ③ Different α values ​​were obtained for each well, as shown in Table 3-2-3, with an average of 0.5422.

[0170] Table 3-2-3 Summary of α values ​​for gas extraction using the improved "single-point method" in gas storage facilities

[0171] hashtag XC1 XC10 XC11 XC15 XC19 XC22 XC3 XC6 XC7 XC8 α value 0.61 0.6 0.6 0.002 0.265 0.11 0.145 2.3 0.04 0.75

[0172] For wells that only underwent a single-point completion test, the productivity under different formation pressures was calculated using the regression α, as shown in Table 3-2-4.

[0173] Based on the binomial production capacity equation or the production capacity equation approximated by the one-point method, the estimated single-well production capacity of a gas storage facility at 30 MPa is between 41 and 1380 × 10⁻⁶. 4 m 3 / d, at 32MPa, the value ranges from 44 to 1496×10. 4 m 3 / d, as shown in Table 3-2-4.

[0174] Table 3-2-4 Estimated Unrestricted Gas Production Flow Rate under Different Formation Pressures in Gas Storage Facilities

[0175]

[0176] Example 3

[0177] This embodiment analyzes the specific gas production capacity of multiple gas wells in a gas storage facility within my country:

[0178] (1) Xiangchu 1 well

[0179] Based on the binomial production capacity equation for gas production in well Xiangchu 1, and considering the pressure loss along the wellbore, the gas production capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas production is obtained, as shown below. Figure 11 As shown, the label "Inflow" represents the formation inflow curve under different wellhead pressures; the label "Outflow" represents the wellbore outflow curve under different formation pressures.

[0180] As can be seen from the gas production capacity analysis chart of Xiangchu 1 well, the tubing size is well matched with the reservoir seepage capacity.

[0181] Based on the intersection diagram of the gas production curve and the critical erosion curve of the 157.08mm inner diameter tubing ( Figure 12 It can be seen that, when the formation pressure is 11.6–30 MPa, the reasonable gas production range of well Xiangchu 1 is (195–494) × 10⁻⁶. 4 m 3 / d;

[0182] Table 3-2-5 Gas Production Statistics of Well Xiangchu 1 under Different Formation Pressure Conditions

[0183]

[0184] (2) Xiangchu 3 well

[0185] Based on the binomial production capacity equation for gas production in well Xiangchu 3, and considering the pressure loss along the wellbore, the gas production capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas production is obtained, as shown below. Figure 13As shown, the label "Inflow" represents the formation inflow curve under different wellhead pressures; the label "Outflow" represents the wellbore outflow curve under different formation pressures.

[0186] As can be seen from the quantitative analysis chart of the gas production capacity of well Xiangchu 3, the diameter of the oil tubing limits the gas production capacity of the well to a certain extent.

[0187] Based on the intersection diagram of the gas production curve and the critical erosion curve of the 100.53mm inner diameter tubing ( Figure 14 It can be seen that, when the formation pressure is 11.6–30 MPa, the reasonable gas production range for well Xiangchu 3 is (91–205) × 10⁻⁶. 4 m 3 / d;

[0188] Table 3-2-6 Gas Production Statistics of Well Xiangchu 3 under Different Formation Pressure Conditions

[0189]

[0190]

[0191] (3) Well Xiangchu 7

[0192] Based on the binomial production capacity equation for gas production in Well Xiangchu 7, and considering the pressure loss along the wellbore, the gas production capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas production is obtained, as shown below. Figure 15 As shown, the label "Inflow" represents the formation inflow curve under different wellhead pressures; the label "Outflow" represents the wellbore outflow curve under different formation pressures.

[0193] As can be seen from the quantitative analysis chart of the gas production capacity of well Xiangchu 7, the diameter of the oil tubing limits the gas production capacity of the well to a certain extent.

[0194] Based on the intersection diagram of the gas production curve and the critical erosion curve of the 100.53mm inner diameter tubing ( Figure 16 It can be seen that, under formation pressures of 11.6–30 MPa, the reasonable gas production range for well Xiangchu 7 is (98–206) × 10⁻⁶. 4 m 3 / d;

[0195] Table 3-2-7 Gas Production Statistics of Well 7 under Different Formation Pressure Conditions (Fangchu 7)

[0196]

[0197]

[0198] (4) Xiangchu 15 well

[0199] Based on the binomial production capacity equation of well Xiangchu 15, and considering the pressure loss along the wellbore, the gas production capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas production is obtained, as shown below. Figure 17 As shown, the label "Inflow" represents the formation inflow curve under different wellhead pressures; the label "Outflow" represents the wellbore outflow curve under different formation pressures.

[0200] As can be seen from the quantitative analysis chart of the gas production capacity of well Xiangchu 15, the diameter of the oil tubing limits the gas production capacity of the well to a certain extent.

[0201] Intersection of injection and production curves (wellhead pressure 13–30 MPa) and critical erosion curves for a 100.53 mm inner diameter tubing. Figure 18 It can be seen that, under formation pressures of 11.6–30 MPa, the reasonable gas production range for well Xiangchu 15 is (77–201) × 10⁻⁶. 4 m 3 / d;

[0202] Table 3-2-8 Gas Production Statistics of Well Xiangchu 15 under Different Formation Pressure Conditions

[0203]

[0204]

[0205] (5) Xiangchu 19 well

[0206] Based on the binomial production capacity equation of well Xiangchu 19, and considering the pressure loss along the wellbore, the gas production capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas production is obtained, as shown below. Figure 19 As shown, the label "Inflow" represents the formation inflow curve under different wellhead pressures; the label "Outflow" represents the wellbore outflow curve under different formation pressures.

[0207] As can be seen from the gas production capacity analysis chart of this well, the diameter of the tubing has a strong limiting effect on the gas production capacity of this well.

[0208] Intersection of injection and production curves (wellhead pressure 13–30 MPa) and critical erosion curves for a 100.53 mm inner diameter tubing. Figure 20 It can be seen that, under formation pressures of 11.6–30 MPa, the reasonable gas production range for well Xiangchu 19 is (100–207) × 10⁻⁶. 4 m 3 / d.

[0209] Table 3-2-9 Gas Production Statistics of Well Xiangchu 19 under Different Formation Pressure Conditions

[0210]

[0211] In summary, the gas production capacity of 22 injection and production wells was calculated using the same method, as shown in Table 3-2-10. Figure 21 As shown. When the upper limit pressure is increased to 30 MPa, the reasonable gas production rate of a single well in the gas storage facility is 39–500 × 10⁻⁶. 4 m 3 / d, the gas storage's gas production capacity increased by 5.17%; when the upper limit pressure is 28MPa, the reasonable gas production per well in the gas storage is 35~481×10 4 m 3 / d; Compared with before pressure increase, the injection and production capacity of a single well increased by 3.5% to 11.43% ( Figure 21 ).

[0212] Table 3-2-10 Data on the Maximum Reasonable Gas Production of Injection and Production Wells in Xiangguosi Gas Storage (10 4 m 3 / d)

[0213]

[0214] Example 4

[0215] This embodiment analyzes the injection capacity of multiple gas wells in a gas storage facility within my country:

[0216] (1) Xiangchu 1 well

[0217] Based on the binomial gas injection capacity equation of Xiangchu-1 well, considering the pressure loss along the wellbore, the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted, and a quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas injection rate is obtained, as shown in the figure. Figure 22 As shown in the figure, "outflow" represents the wellbore outflow curve under different wellhead pressures, and "inflow" represents the formation inflow curve under different formation pressures.

[0218] As can be seen from the gas injection capacity analysis chart of Xiangchu 1 well, the tubing size is well matched with the reservoir seepage capacity.

[0219] Intersection of gas injection curves (wellhead pressure 13–30 MPa) and critical erosion curves from a 157.08 mm inner diameter tubing. Figure 23 It can be seen that, when the formation pressure is 11–30 MPa, the reasonable gas injection rate range for well Xiangchu 1 is (462–582) × 10⁻⁶. 4 m 3 / d.

[0220] Table 3-2-11 Statistical table of gas injection volume of well Xiangchu 1 under different formation pressure conditions

[0221]

[0222] (2) Xiangchu 3 well

[0223] Based on the binomial gas injection capacity equation of well Xiangchu 3, and considering the pressure loss along the wellbore, the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas injection volume is obtained, as shown below. Figure 24 As shown.

[0224] As can be seen from the quantitative analysis chart of the gas injection capacity of well Xiangchu 3, the diameter of the oil tubing can meet the gas injection capacity requirements well.

[0225] Intersection of gas injection curves (wellhead pressure 13-30 MPa) and critical erosion curves from a 100.53 mm inner diameter tubing. Figure 25 It can be seen that, when the formation pressure is 11–30 MPa, the reasonable gas injection rate range for well Xiangchu 3 is (164–238) × 10⁻⁶. 4 m 3 / d.

[0226] Table 3-2-12 Statistical table of gas injection volume of well Xiangchu 3 under different formation pressure conditions

[0227]

[0228]

[0229] (3) Well Xiangchu 7

[0230] Based on the binomial gas injection capacity equation of well Xiangchu 7, and considering the pressure loss along the wellbore, the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressures are predicted. A quantitative relationship chart between bottom hole pressure, wellhead pressure, and gas injection volume is obtained, as shown below. Figure 26 As shown.

[0231] As can be seen from the quantitative analysis chart of the gas injection capacity of well Xiangchu 7, the diameter of the oil tubing can meet the gas injection capacity requirements well.

[0232] Intersection of gas injection curves (wellhead pressure 13-30 MPa) and critical erosion curves from a 100.53 mm inner diameter tubing. Figure 27 It can be seen that, when the formation pressure is 11–30 MPa, the reasonable gas injection rate range for well Xiangchu 7 is (161–233) × 10⁻⁶. 4 m 3 / d.

[0233] Table 3-2-13 Statistics of Gas Injection Volume in Well Xiangchu 7 under Different Formation Pressures

[0234]

[0235] (4) Xiangchu 15 well

[0236] Since no gas injection capacity test was conducted on well Xiangchu 15, the gas production capacity equation was used for the reasonable gas injection capacity analysis. The intersection of the injection-production curves (wellhead pressure 13–30 MPa) and the critical erosion curves of a 100.53 mm inner diameter tubing is shown in the figure. Figure 28 It can be seen that when the formation pressure is 11-30 MPa, the reasonable gas injection rate range for well Xiangchu 15 is (165-232)×10. 4 m 3 / d.

[0237] Table 3-2-14 Statistics of Gas Injection Volume in Well Xiangchu 15 under Different Formation Pressures

[0238]

[0239]

[0240] (5) Xiangchu 19 well

[0241] Since no gas injection capacity test was conducted on well Xiangchu 19, the gas production capacity equation was used for the reasonable gas injection capacity analysis. The intersection of the injection-production curves (wellhead pressure 13–30 MPa) and the critical erosion curves of a 100.53 mm inner diameter tubing is shown in the figure. Figure 29 It can be seen that, when the formation pressure is 11–30 MPa, the reasonable gas injection rate range for well Xiangchu 19 is (170–235) × 10⁻⁶. 4 m 3 / d.

[0242] Table 3-2-15 Statistics of Gas Injection Volume in Well Xiangchu 19 under Different Formation Pressure Conditions

[0243]

[0244] In summary, the gas production capacity of 21 injection and production wells was calculated using the same method, as shown in Table 3-2-16. Figure 30 As shown. Within the upper and lower pressure operating range of the gas storage facility, the reasonable gas injection rate for a single well in this gas storage facility is 8–590 × 10⁻⁶. 4 m 3 / d( Figure 30 ).

[0245] Table 3-2-16 Statistical table of gas injection volume under different formation pressure conditions (104 m3 / d)

[0246]

[0247]

[0248] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for analyzing the injection and production capacity of a gas storage facility, characterized in that, It includes at least the following steps: S1: Construct the gas extraction binomial equation and the gas injection binomial equation; S2: Divide the gas storage into several single wells to be analyzed. Based on the historical gas injection capacity test data and gas production capacity test data of the single wells to be analyzed, substitute them into the gas production binomial equation and gas injection binomial equation in S1 to obtain the gas production binomial capacity equation and gas injection binomial capacity equation respectively. S3: Based on the production binomial production capacity equation and injection binomial production capacity equation in S2, the unobstructed flow rate of the production capacity test under the predetermined pressure is obtained; based on the unobstructed flow rate results of the production capacity test, the "one-point method" is improved to obtain the different α values ​​and their average values ​​for each well to be analyzed. S4: Based on the actual test results of the single well to be analyzed, select the binomial production capacity equation or the improved "one-point method" to obtain the range value of the single well to be analyzed in the gas storage under the predetermined pressure.

2. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 1, characterized in that: The process of constructing the binomial equation for gas extraction in S1 is as follows: During the gas extraction process, considering both the convenience of field application and the accuracy of calculation, a binomial inflow dynamic model is adopted, and its formula is: In the formula: p r Formation pressure, MPa; p wf The bottom hole flowing pressure is in MPa. A and B are binomial productivity coefficients, in MPa. 2 ·d / (10 4 m 3 (mPa·s), (MPa·d) 2 / [(10 4 m 3 ) 2 ·mPa·s];q g For gas production, 10 4 m 3 / d.

3. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 1, characterized in that: The process of constructing the gas injection binomial equation in S1 is as follows: For gas injection, if a gas injection capacity test has been conducted, the gas injection binomial productivity equation is used for calculation; if no gas injection capacity test has been conducted, it is assumed that the injection capacity and production capacity of the vertical well are the same, resulting in a formation outflow dynamic model with the bottom of the well as the node:

4. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 1, characterized in that: In S3, the specific steps to improve the "one-point method" are as follows: S31: Calculate the one-point unobstructed flow rate of each well under different formation pressures at different times during the gas production period; S32: By changing the α value, the unobstructed flow rate calculated by the one-point method is matched with the unobstructed flow rate calculated by the production well test: S33: Obtain the different α values ​​and their average values ​​for each well.

5. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 1, characterized in that: S2 also includes a method for calculating and analyzing the gas production capacity of the single well to be analyzed, which specifically includes: S221: Based on the binomial gas production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas production capacity under different bottom hole pressures and the corresponding wellhead pressure, and obtain a quantitative relationship chart between bottom hole pressure, wellhead pressure and gas production: S222: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas production in the single well to be analyzed in S221, determine the matching relationship between tubing size and reservoir permeability: S223: The intersection diagram is obtained by drawing the gas production curve of the oil pipe with the predetermined diameter and the critical erosion curve. The intersection diagram shows the reasonable gas production range of the single well to be analyzed when the predetermined formation pressure range is within the range.

6. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 5, characterized in that: It also includes S224: by analyzing the gas production capacity of all the individual wells to be analyzed, the reasonable gas production range of all individual wells in the gas storage is obtained.

7. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 1, characterized in that: S2 also includes a method for calculating and analyzing the gas injection capacity of the single well to be analyzed, which specifically includes: S231: Determine whether the gas injection capacity test has been carried out for the single well to be analyzed. If yes, then based on the gas injection binomial production capacity equation of the single well to be analyzed, considering the pressure loss along the wellbore, predict the gas injection capacity under different bottom hole pressures and the corresponding wellhead pressure, obtain the quantitative relationship chart between bottom hole pressure, wellhead pressure and gas injection volume, and jump to S232 for analysis. If no, then the gas injection capacity analysis adopts the gas production capacity equation; and jump to S233 for analysis. S232: Based on the quantitative relationship chart of bottom hole pressure, wellhead pressure and gas injection volume in the single well to be analyzed in S232, determine the matching relationship between tubing size and reservoir permeability: S233: The intersection diagram is obtained by drawing the gas injection curve of the tubing with the predetermined diameter and the critical erosion curve. The intersection diagram shows the reasonable gas injection range of the single well to be analyzed when the predetermined formation pressure range is within the range.

8. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 6, characterized in that: S234: By analyzing the gas injection capacity of all the individual wells to be analyzed, the reasonable gas injection volume range of all individual wells in the gas storage is obtained.

9. A method for analyzing the injection and production capacity of a gas storage facility as described in claim 5 or 7, characterized in that: The inner diameter of the oil pipe is 100.53 mm or 157.08 mm.

10. The method for analyzing the injection and production capacity of a gas storage facility as described in claim 2, characterized in that: During gas extraction, the dynamic model of wellbore outflow uses the vertical pipe flow pressure calculation formula: In the formula: p wh γ is the wellhead flow pressure, MPa; s is the pressure coefficient, dimensionless; f is the tubing friction coefficient; γ g ρ is the relative density of the gas; H is the depth of the middle of the producing layer, m; d is the inner diameter of the tubing, m; e is the absolute roughness of the tubing interior, m; R e It is the Reynolds number.

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