A method, system, device and medium for obtaining a leakage point of a gas injection string of a gas well

Abstract

The application discloses a kind of gas injection string leak point acquisition method, system, equipment and medium, it includes: response to leakage signal, measured pressure of annulus string wellhead;According to the leakage depth calculation model constructed in advance, the leakage depth is calculated;Leakage depth calculation model includes: the first relationship of annulus string wellhead pressure, leakage depth and gas injection string related parameters;The second relationship that the depth of gas injection string changes with step length;Initial known parameter is brought into first relationship and second relationship, leakage depth is gradually accumulated based on step length, annulus string wellhead pressure is calculated according to accumulated leakage depth, until the difference of annulus string wellhead pressure and measured pressure is in preset range, and the corresponding leakage depth is output. Realize the positioning of leak point position, in the process of string repair, leakage point can be quickly found, and the repair efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas well logging, and particularly relates to a gas well gas injection string leakage point acquisition method, system, device and medium. BACKGROUND

[0002] In the gas injection and production process of an oil and gas well, due to the small viscosity and strong diffusion of gas, when there is a leakage point in the injection and production string, the injected gas will inevitably seep from the high-pressure injection string to the annular area of the low-pressure injection and production string and the oil layer casing, resulting in annular pressure (composed of multiple annular strings). The annular pressure of the injection and production well will bring huge safety hazards to the wellhead equipment and ground facilities, especially for gas storage wells. Once leakage or loss of control occurs, it will cause irreparable economic losses and huge social negative impact on the enterprise.

[0003] In the prior art, there are two methods of tracer detection and pulling out the string to find the leakage point, but both have obvious shortcomings, as follows: the tracer detection method for finding the leakage point of the string is difficult to determine the type of tracer for different injection gas and difficult to lower the tracer detection instrument in the wellbore with the completion string, and it is difficult to determine the specific leakage point position. The method of pulling out the string to find the leakage point needs to be checked manually at each position, and the leakage point finding is blind, time-consuming and laborious, and difficult to find. Therefore, a gas well gas injection string leakage point acquisition method is needed to acquire the leakage position. SUMMARY

[0004] The embodiments of the present application provide a gas well gas injection string leakage point acquisition method, system, device and medium, which at least partially solve the technical problem that the leakage point position of the gas well string cannot be positioned in the prior art, and achieve the technical effect of accurately acquiring the leakage point position.

[0005] In the first aspect, to solve the above technical problems, the embodiments of the present application provide the following technical solutions:

[0006] A gas well gas injection string leakage point acquisition method, comprising:

[0007] In response to the leakage signal, measuring the measured pressure at the wellhead of the annular string;

[0008] According to a leakage point depth calculation model constructed in advance, calculating the leakage point depth; the leakage point depth calculation model comprises:

[0009] The first relationship among the annular string wellhead pressure, the leakage point depth, and the related parameters of the gas injection string; the second relationship that the depth of the gas injection string changes with the step;

[0010] The initial known parameters are brought into the above first relationship and the above second relationship, the leakage point depth is accumulated step by step based on the above step, the annulus string wellhead pressure is calculated according to the accumulated leakage point depth, and until the difference between the annulus string wellhead pressure and the measured pressure is within a preset range, the corresponding leakage point depth is output.

[0011] Optionally, the step of calculating the annulus string wellhead pressure according to the accumulated leakage point depth specifically comprises:

[0012] A first depth of the annulus gas column is obtained.

[0013] When the leakage point position is within the first depth range, the pressure of the annulus string leakage point position is equal to the pressure of the leakage point position in the annulus gas column.

[0014] Optionally, the step of calculating the annulus string wellhead pressure according to the accumulated leakage point depth specifically further comprises:

[0015] A second depth of the annulus liquid column is obtained.

[0016] When the leakage point position is within the second depth range, the pressure of the annulus string leakage point position is equal to the sum of the pressures of the annulus gas column and the annulus liquid column at the leakage point position.

[0017] Optionally, after the corresponding leakage point depth is output, the method further comprises:

[0018] The leakage point size is calculated according to a leakage point size calculation model constructed in advance, and the leakage point size calculation model comprises:

[0019] A third relationship between the pressure of the annulus string at the leakage point, the pressure of the gas injection string, the leakage gas amount, and the string size;

[0020] A fourth relationship between the leakage point inner diameter at the leakage point, the leakage gas amount, the annulus string pressure, and the gas injection string pressure;

[0021] The third relationship and the fourth relationship are substituted into the leakage point depth to obtain the inner diameter of the leakage point.

[0022] Optionally, when the pressure of the annulus string at the leakage point is calculated, in a specific embodiment, the pressure of the annulus string at the leakage point is calculated according to the following formula:

[0023] When the leakage point position is within the first depth range, the pressure of the annulus string leakage point position is equal to the pressure of the leakage point position in the annulus gas column.

[0024] When the leakage point position is within the second depth range, the pressure of the annulus string leakage point position is equal to the sum of the pressures of the annulus gas column and the annulus liquid column at the leakage point position.

[0025] Optionally, the method further comprises:

[0026] When the gas well is a deviated well,

[0027] The depth of the leakage point is equal to the projection depth of the deviated well in the vertical direction.

[0028] Optionally, before the response to the leakage signal, specifically comprising:

[0029] The pressure detection device is arranged in the annular gas column;

[0030] When the pressure value of the detection device exceeds the preset threshold value, the leakage signal of the detection device is triggered.

[0031] In a second aspect, a gas well injection string leakage point acquisition system is provided, comprising:

[0032] A calculation module is configured to calculate the leakage point depth according to a leakage point depth calculation model constructed in advance, wherein the leakage point depth calculation model comprises a first relationship between the annulus string wellhead pressure, the leakage point depth, and the related parameters of the injection string, a second relationship between the depth of the injection string and the step length, and an initial known parameter is brought into the first relationship and the second relationship, and the leakage point depth is gradually accumulated based on the step length, the annulus string wellhead pressure is calculated according to the accumulated leakage point depth, and the corresponding leakage point depth is output until the difference between the annulus string wellhead pressure and the measured pressure is within a preset range.

[0033] In a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, wherein the processor executes the computer program to realize the steps corresponding to the method of the first aspect.

[0034] In a fourth aspect, a computer readable storage medium is provided, which stores a computer program executable by a processor to realize the steps corresponding to the method of the first aspect.

[0035] The one or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

[0036] In the embodiments of the present application, the leakage point depth calculation model is used to associate the depth corresponding to the leakage point and the annulus string wellhead pressure, so as to calculate the annulus string wellhead pressure corresponding to the depth. However, the formula obtained by association can only calculate the wellhead pressure corresponding to the specified leakage point depth in the calculation. Therefore, the step-by-step accumulation method is used to iterate according to the step length, and the actual measured wellhead pressure is used to judge the calculation result, so as to determine the leakage point depth. Thus, the position of the leakage point is located, and the leakage point can be quickly found in the process of repairing the string, thereby improving the repair efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present application, and all other drawings obtained by those skilled in the art without creative effort based on these drawings are within the scope of protection of the present application.

[0038] Figure 1 A flow chart of a gas well gas injection string leakage point acquisition method provided by the present application is shown in the figure.

[0039] Figure 2 A schematic diagram of an annular string and a gas injection string in the present application is shown in the figure.

[0040] Figure 3 A schematic diagram of a deviation well leakage point depth conversion in the present application is shown in the figure.

[0041] Figure 4 A structural schematic diagram of a gas well gas injection string leakage point acquisition system provided by the present application is shown in the figure.

[0042] Figure 5 A structural schematic diagram of an electronic device provided by the present application is shown in the figure.

[0043] Reference signs: 1, annular string; 11, annular gas column; 12, annular liquid column; 2, gas injection string; 3, leakage point position. DETAILED DESCRIPTION

[0044] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art without creative effort based on the embodiments in the present application are within the scope of protection of the present application.

[0046] It should be noted that: similar reference signs and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0047] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the term "arrangement" should be understood broadly, for example, it can be fixed arrangement, or detachable arrangement, or integrally arranged; it can be directly arranged, or indirectly connected through intermediate medium. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances. In addition, the terms "first", "second", "third" and the like are only used for differentiation and description, and cannot be understood as indicating or implying relative importance.

[0048] It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solutions of the present application, and are not limitations of the technical solutions of the present application. In the case of no conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0049] The technical solutions of the embodiments of the present application are as follows to solve the above technical problems:

[0050] When the gas injection string 2 has a leakage point, the gas enters the annular string 1, and the gas injection string 2 and the annular string 1 at this time are equivalent to a communicating vessel. According to the principle of the communicating vessel, the calculation formula of the depth, static pressure and gas injection wellhead pressure of the two is the same at the shut-in stage, and based on this, the annular wellhead pressure can be calculated. The above formula can only calculate the annular wellhead pressure corresponding to one depth value, so the calculation is brought into the pipe string at multiple heights, and the actual detected pressure value is used to judge the calculation result, so as to determine the leakage point position.

[0051] In the embodiments of the present application, a gas well gas injection string 2 leakage point acquisition method is provided, as shown in Figure 1 The method comprises steps S101-S102:

[0052] Step S101, in response to the leakage signal, measuring the measured pressure of the annular string 1 wellhead;

[0053] It should be noted that whether the gas injection string 2 (i.e. the oil pipe) has a leakage point, mainly detects the pressure change in the annular string 1. Because the pressure change in the annular string 1 is small when there is no gas from the gas injection string 2, most of which is because the expansion of the gas injection string 2 causes some extrusion to the annular string 1. But when the leakage point occurs, the gas in the gas injection string 2 enters the annular string 1, and the two are equivalent to a communicating vessel, the gas injection string 2 continuously injects gas into the annular string 1, increases the pressure, thereby causing a large pressure change in the annular string 1. Therefore, the pressure detection device is arranged in the annular gas column 11 in the present embodiment; when the pressure value of the detection device exceeds the preset threshold value, the leakage signal of the detection device is triggered. After receiving the leakage signal, the measured pressure of the annular string 1 wellhead is measured by using the gas pressure detection device arranged at the wellhead of the annular string 1.

[0054] Step S102, calculating the leakage point depth according to the leakage point depth calculation model constructed in advance; the leakage point depth calculation model comprises:

[0055] a first relationship of the annulus string 1 wellhead pressure, the leakage point depth, and the injection string 2 related parameters;

[0056] Firstly, for the establishment of the first relationship, it is mainly obtained according to the calculation formula of the injection string 2 depth in the shut-in stage, the static pressure corresponding to the depth, and the injection string 2 wellhead pressure, which is the existing formula. The specific calculation process is as follows:

[0057] It is known that:

[0058]

[0059] Wherein, p 注气h is the pressure at the depth h of the injection string 2 in the shut-in stage, p 注气井口 is the injection string 2 wellhead pressure, T 注气h is the temperature at the depth h of the injection string 2, Z 注气h is the gas deviation coefficient at the depth h of the injection string 2, and γ g is the relative density of the gas well.

[0060] Because when the leakage point appears, the injection string 2 and the annulus string 1 are equivalent to a communicating vessel, the pressures of the two at the same height position are equal, so the two satisfy the following formula in the stable stage (i.e. the shut-in stage):

[0061]

[0062] Wherein, p 环空h is the pressure at the depth h of the annulus string 1 in the shut-in stage, p 环空井口 is the annulus string 1 wellhead pressure, T 环空h is the temperature at the depth h of the annulus string 1, and Z 环空h is the gas deviation coefficient at the depth h of the annulus string 1.

[0063] It should be noted that the gas deviation coefficient can be calculated from the pressure and temperature at the corresponding string position, and the temperature can be calculated from the depth at the corresponding string position. The specific calculation formula is as follows:

[0064] Z 注气 h=f(p 注气 h,T 注气 h) (3)

[0065] T 注气 h=T 井口 +t*h (4)

[0066] Z 环空h = f(p 环空h ,T 环空 h) (5)

[0067] h = f(p 环空 ,T 井口 +t*h (6)

[0068] Wherein, t is the geothermal gradient, T 井口 is the wellhead temperature. The existing formula.

[0069] It should be noted that the calculation formula of gas deviation factor Z 环空h f(p 环空h ,T 环空h ) is the existing formula, which can be referred to in the paper: Dong Meng. Comparison and application of natural gas compression factor calculation method [D]. Northeast Petroleum University, 2015. The compression factor in the paper is the gas deviation factor. Similarly, the gas deviation factor Z 注气h is also calculated according to the paper.

[0070] Then the second relationship between the depth of the gas injection string 2 and the step length is established; The second relationship is established because the above formula (2) can only calculate the wellhead pressure corresponding to one height value after substituting the known data, but this data is not necessarily the leak point position, so the step length is set to establish the second relationship by gradually accumulating, and the leak point height is h 漏 , and h 漏 is substituted into the formula (1) to (6) in the subsequent calculation. The specific formula is as follows:

[0071] h 漏i = h 漏0 +(i)I (7)

[0072] Wherein, h 漏i is the string leak point depth after the i-th superposition, h 漏0 is the string leak point depth obtained by the first calculation, I is the step length, and i = 1, 2, 3, 4……n.

[0073] The initial known parameters are brought into the first relationship and the second relationship, the leak point depth is gradually accumulated based on the step length, the annular string 1 wellhead pressure is calculated according to the accumulated leak point depth, until the difference between the annular string 1 wellhead pressure and the measured pressure is within the preset range, and the corresponding leak point depth is output.

[0074] It should be noted that the initial known parameters include: gas injection string 2 wellhead pressure, wellhead temperature, gas well relative density. First, these known parameters are brought into formula (2) to (6) to obtain the initial depth value. Using this initial depth value, the leak point depth is gradually accumulated based on the step size, and the annular string 1 wellhead pressure corresponding to different depths is calculated, which is equivalent to calculating the position of the step distance from the top of the string downward one by one. Finally, the calculation results are compared with the measured pressure, and if the error is within the preset range, it is considered that the depth value at this time is the leak point depth. Otherwise, the depth value is continued to be accumulated. The specific calculation process is as follows:

[0075] Let the leak point depth be h 漏 , the initial leak point depth be h 漏0 , and the i-th superimposed string leak point depth be h 漏i . Since the initial gas injection string 2 wellhead pressure p 注气井口 , wellhead temperature T 井口 and gas well relative density γ g are known, they are brought into formula (2) to (6) to obtain:

[0076]

[0077] Thus, using the initial leak point depth h 漏0 , the initial annular string 1 wellhead pressure p is calculated by back calculation. At this time, it is compared with the measured value p 环空井口实测 of the annular string 1 wellhead.

[0078] If ε is the error value, which is 0.01 MPa, then h 漏0 is considered as the leak point depth. Otherwise, start to gradually accumulate the leak point depth based on the step size, and the specific calculation process is as follows:

[0079] Since the annular string 1 contains both gas and liquid, the calculation of the annular string 1 containing different media is calculated separately, as shown in Figure 2 . Let the depth of the annular gas column 11 be h 环空气柱 , the depth of the annular liquid column 12 be h 环空液柱 , and the depth values of h 环空气柱 and h 环空液柱 be known.

[0080] With the accumulation of the leak point position, when h 漏i ≤ h 环空气柱 , that is, the leak point is located in the range of the annular gas column 11 (i.e. the first range), the pressure of the empty string leak point position is equal to the pressure of the leak point position in the annular gas column 11, as shown in (8). But when h 漏i > h 环空气柱When the leak point is located within the range of the annular liquid column 12 (i.e., the second range), the pressure at the leak point in the annular tubing 1 is equal to the sum of the pressures at the leak point in the annular air column 11 and the annular liquid column 12. The specific calculation formula is as follows:

[0081]

[0082] Where, p 环空h漏i ρ is the pressure at the leak point location after i stacking events within the annular tubing string 1. 液 The density of the liquid column inside the annulus.

[0083] Based on the principle of communicating vessels, we can obtain:

[0084]

[0085] Based on formula (10) and substituting the known parameters, the wellhead pressure of the annulus tubing string 1 after the i-th depth accumulation is obtained. Compare it with the measured value p at the wellhead of annular tubing string 1 环空井口实测 contrast.

[0086] like Then h is determined 漏i This represents the depth of the leak point; conversely, the depth is accumulated, and the corresponding wellhead pressure of the annulus tubing string 1 is obtained, until a result is obtained that meets the requirements. This determination requires the wellhead pressure of the annulus tubing string to be measured. This allows for the location of the leak, enabling rapid identification of the leak during tubing string maintenance and improving maintenance efficiency.

[0087] It should also be noted that the above embodiments are for the case where the gas well is a vertical well. When the gas well is an inclined well, the depth of the leak point is equal to the projected depth of the inclined well in the vertical direction, such as... Figure 3 The leak point is shown as location 3. That is:

[0088]

[0089] Among them, h 漏 h is the height of the leak point. 漏斜 denoted as the length of the inclined shaft, and 'a' as the angle between the inclined shaft and the vertical direction.

[0090] In some embodiments of the present invention, after calculating the leak depth, the size of the leak can also be calculated to estimate the leakage amount, thus the leak point acquisition method further includes:

[0091] According to the pre-constructed leak size calculation model, the leak size is calculated; the leak size calculation model includes: the third relationship of the annulus string 1 pressure at the leak point, the gas injection string 2 pressure, the gas leakage amount and the string size; the fourth relationship of the leak point inner diameter at the leak point, the gas leakage amount, the annulus string 1 pressure and the gas injection string 2 pressure; the third relationship and the fourth relationship are obtained after the leak depth is substituted, and the inner diameter of the leak point is obtained.

[0092] It should be noted that when establishing the first relationship, the gas injection string 2 depth and pressure formula in the gas injection stage need to be used, as follows:

[0093] It is known that:

[0094]

[0095] Wherein, q 注入 is the gas injection amount, D 注气内 is the inner diameter of the gas injection string 2.

[0096] Because the annulus string 1 contains both gas and liquid, the calculation of the annulus string 1 containing different media is calculated separately. The depth of the annulus gas column 11 is h 环空气柱 , the depth of the annulus liquid column 12 is h 环空液柱 , and the depth values of h 环空气柱 and h 环空液柱 are known. Assuming that the gas leakage amount of the gas injection string 2 leak point into the annulus is q 漏 , the pressure p 漏 at the leak depth h 环空h漏 in the annulus is calculated as follows:

[0097] When h 漏 ≤ h 环空气柱 , that is, the leak point is located in the range of the annulus gas column 11 (i.e. the first range),

[0098]

[0099] Because the relationship between the leakage amount q 漏 at the leak depth h 漏 and (p 环空h漏 / p 注气h漏 ) is:

[0100]

[0101] Wherein, k is the adiabatic index of the gas, and d is the inner diameter of the leak point.

[0102] The calculated leak depth is substituted into formulas (12) and (13) to calculate the inner diameter of the leak point.

[0103] When h 漏 > h环空气柱 Time,

[0104]

[0105] The calculated leak point depth is brought into formulas (13) and (14), and thus the inner diameter of the leak point is obtained. Therefore, the position and size of the leak point are obtained, further providing a reference for oil pipe maintenance. The convenience of maintenance is improved.

[0106] Based on the same inventive concept, as shown in Figure 4 The embodiment of the present application provides a gas well gas injection string leak point acquisition system, which comprises:

[0107] The detection module 201 measures the measured pressure of the annulus string 1 wellhead in response to the leakage signal.

[0108] The calculation module 202 is configured to calculate the leak point depth according to a leak point depth calculation model constructed in advance; the leak point depth calculation model comprises a first relationship among the annulus string 1 wellhead pressure, the leak point depth, and related parameters of the gas injection string 2; a second relationship that the depth of the gas injection string 2 changes with a step; the initial known parameters are brought into the first relationship and the second relationship, the leak point depth is gradually accumulated based on the step, the annulus string 1 wellhead pressure is calculated according to the accumulated leak point depth, until the difference between the annulus string 1 wellhead pressure and the measured pressure is within a preset range, and the corresponding leak point depth is output.

[0109] Based on the same inventive concept, the embodiment of the present application provides an electronic device, as shown in Figure 5 The electronic device comprises a memory 302, a processor 301, and a computer program stored in the memory 302 and capable of running on the processor 301, and the processor 301 implements the above-mentioned gas well gas injection string leak point acquisition method when executing the computer program.

[0110] Based on the same inventive concept, the embodiment of the present application provides a computer readable storage medium, which stores a computer program, characterized in that the program is executed by a processor to implement the above-mentioned gas well gas injection string 2 leak point acquisition method.

[0111] The computer program instructions can also be loaded onto a computer, other programmable data processing apparatus, or other processing device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other processing device to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions of the flowchart block(s) or step(s) of the flowchart block(s). Figure 1 one or more functions specified by one or more of the flowchart blocks or steps of the flowchart blocks. Figure 1 one or more functions specified by one or more of the flowchart blocks or steps of the flowchart blocks.

[0112] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the preferred embodiments by those of skill in the art once they have the benefit of the present disclosure without departing from the spirit and scope of the application. Accordingly, it is intended that the appended claims be interpreted as including all such additional variations and modifications as fall within the scope of the present application and its equivalents.

[0113] Obviously, numerous modifications and variations of the present application are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A method for obtaining leak points in a gas well injection tubing string, characterized in that, The method includes: In response to a leakage signal, the measured pressure at the wellhead of the annular tubing string is measured; The leak depth is calculated based on a pre-constructed leak depth calculation model; the leak depth calculation model includes: The first relationship between the annular tubing wellhead pressure, the leak point depth, and the relevant parameters of the gas injection tubing; the second relationship between the depth of the gas injection tubing and the step size. Substitute the initial known parameters into the first relationship and the second relationship, and gradually accumulate the leakage depth based on the step size. Calculate the annular tubing wellhead pressure based on the accumulated leakage depth until the difference between the annular tubing wellhead pressure and the measured pressure is within a preset range, and output the corresponding leakage depth. The step of substituting the initial known parameters into the first and second relationships, progressively accumulating the leakage depth based on the step size, and calculating the annular tubing wellhead pressure based on the accumulated leakage depth includes: When a leak occurs, the pressure is equal when the injection string and the annulus string are at the same height. During the shutdown phase, the injection string and the annulus string satisfy the following formula: Wherein, p 环空h The pressure at depth h of the annulus tubing during the injection stop phase, p 环空井口 The annular tubing wellhead pressure, T 环空h The temperature at depth h of the annular tubing, Z 环空h The gas deviation coefficient at depth h of the annular tubing; Alternatively, calculate using the following formula: Wherein, the wellhead pressure For the annular tubing after the i-th depth accumulation, the ρ 液 h is the density of the liquid column inside the annulus. 漏i h represents the depth of the leakage point in the tubing after the i-th stacking. 环空气柱 The depth of the annular air column.

2. The method as described in claim 1, characterized in that, The step of calculating the annular tubing wellhead pressure based on the accumulated leak depth specifically includes: Obtain the first depth of the annular air column; When the leak point is located within the first depth range, the pressure at the leak point in the annular tubing is equal to the pressure at the leak point within the annular air column.

3. The method as described in any one of claims 2, characterized in that, The step of calculating the annular tubing wellhead pressure based on the accumulated leak depths further includes: Obtain the second depth of the annular liquid column; When the leak point is within the second depth range, the pressure at the leak point of the annular tubing is equal to the sum of the pressures of the annular air column and the annular liquid column at the leak point.

4. The method as described in claim 3, characterized in that, After outputting the corresponding leak depth, the method further includes: The size of the leak is calculated based on a pre-built leak size calculation model; the leak size calculation model includes: The third relationship between the pressure of the annular tubing at the leak point, the pressure of the injection tubing, the leakage rate, and the tubing size; The fourth relationship between the leak point's inner diameter, leakage volume, annular tubing pressure, and injection tubing pressure at the leak point. The third and fourth relationships, after incorporating the leak depth, yield the inner diameter of the leak.

5. The method as described in claim 4, wherein when calculating the pressure of the annular tubing at the leak point, it is characterized in that, When the leak point is within the first depth range, the pressure at the leak point in the annular tubing is equal to the pressure at the leak point within the annular air column; When the leak point is within the second depth range, the pressure at the leak point of the annular tubing is equal to the sum of the pressures of the annular air column and the annular liquid column at the leak point.

6. The method according to any one of claims 1 to 5, characterized in that, The method further includes: When the gas well is an inclined well The depth of the leak point is equal to the projected depth of the inclined well in the vertical direction.

7. The method according to any one of claims 1 to 5, characterized in that, Prior to responding to the leakage signal, specifically including: A pressure detection device is installed inside the annular air column; When the pressure value of the detection device exceeds a preset threshold, the detection device is triggered to send a leakage signal.

8. A system for detecting leaks in a gas well injection tubing string, characterized in that, The system includes: The detection module, in response to a leakage signal, measures the actual pressure at the wellhead of the annular tubing string; The calculation module is used to calculate the leakage depth based on a pre-constructed leakage depth calculation model. The leakage depth calculation model includes: a first relationship between the annular tubing wellhead pressure, the leakage depth, and relevant parameters of the gas injection tubing; a second relationship between the depth of the gas injection tubing and the step size; by substituting the initial known parameters into the first and second relationships, the leakage depth is gradually accumulated based on the step size, and the annular tubing wellhead pressure is calculated based on the accumulated leakage depth until the difference between the annular tubing wellhead pressure and the measured pressure is within a preset range, and the corresponding leakage depth is output. Specifically, when the calculation module substitutes the initial known parameters into the first and second relationships, progressively accumulates the leakage depth based on the step size, and calculates the annular tubing wellhead pressure based on the accumulated leakage depth, it is used for: When a leak occurs, the pressure is equal when the injection string and the annulus string are at the same height. During the shutdown phase, the injection string and the annulus string satisfy the following formula: Wherein, p 环空h The pressure at depth h of the annulus tubing during the injection stop phase, p 环空井口 The annular tubing wellhead pressure, T 环空h The temperature at depth h of the annular tubing, Z 环空h The gas deviation coefficient at depth h of the annular tubing; Alternatively, calculate using the following formula: Wherein, the wellhead pressure For the annular tubing after the i-th depth accumulation, the ρ 液 h is the density of the liquid column inside the annulus. 漏i h represents the depth of the leakage point in the tubing after the i-th stacking. 环空气柱 The depth of the annular air column.

9. An electronic device, characterized in that, The electronic device includes: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps corresponding to the method as described in any one of claims 1 to 7.

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