A method and apparatus for determining water influx in a gas reservoir

Abstract

This invention discloses a method and apparatus for determining water intrusion in a gas reservoir. The method includes: determining the original gas-water interface, the gas-water interface at a set time, and water saturation distribution data of the gas reservoir; obtaining a dynamic model containing a porosity field and a water saturation field at the set time using the water saturation distribution data at the set time and a three-dimensional geological model of the gas reservoir; selecting effective grids from the grids located between the original gas-water interface and the gas-water interface at the set time in the dynamic model based on the lower limit of the effective porosity of the gas reservoir; determining the water intrusion amount for each effective grid based on its volume, porosity, and water saturation at the set time; and obtaining the water intrusion amount of the gas reservoir at that time from the water intrusion amount of each grid. This method is relatively simple and fast in calculation, requires fewer parameters, has fewer subjective human factors, can calculate the water intrusion amount of the gas reservoir relatively accurately, reduces the uncertainty in the water intrusion amount calculation process, and has a wide range of applications.

Description

Technical Field

[0001] This invention relates to the field of gas reservoir engineering technology, and in particular to a method and apparatus for determining water intrusion in gas reservoirs. Background Technology

[0002] Methods for calculating water intrusion in gas reservoirs have evolved from the material balance theory and mainly include the following: ① Unsteady-state method, namely the Van Everdingen-Hurst method, which assumes that formation water flows radially in a plane, the gas-water boundary pressure is constant, and the formation is homogeneous and of uniform thickness. A dimensionless method for calculating water intrusion is derived through the seepage differential equation. ② Quasi-steady-state material balance method, a semi-analytical method, treats the gas zone as an "enlarged well" and water intrusion as a single-phase flow from the water body to the "enlarged well." Water intrusion is calculated by applying parameters such as the gas zone radius, water zone radius, effective rock compressibility coefficient of the water zone, and formation properties of the water zone. ③ Apparent geological reserves method, which derives the apparent geological reserves of the gas reservoir based on the material balance equation of the water-driven gas reservoir. The equation relating apparent geological reserves to actual geological reserves shows that the difference between apparent geological reserves and actual geological reserves is related to the water intrusion of the gas reservoir. By plotting the curve relating apparent geological reserves to gas production, the water intrusion of the gas reservoir can be calculated. The calculation requires parameters such as the effective compressibility coefficient of rock and the compressibility coefficient of formation water. ④ The polynomial mass balance method is a mathematical fitting method. This method uses mathematical means to transform the mass balance equation into a polynomial equation. By applying parameters such as the effective compressibility coefficient of rock and the compressibility coefficient of formation water to fit the coefficients of the polynomial equation, the water intrusion is finally calculated. Summary of the Invention

[0003] The inventors discovered that the above-mentioned commonly used methods for calculating water intrusion in gas reservoirs play a crucial role in the scientific development of edge-and-bottom water gas reservoirs and the stable production of gas fields. However, they all have certain limitations: ① Each method has certain assumptions and applicable ranges, and can only be used to calculate water intrusion under specific assumptions; ② Static parameters of the water area are difficult to obtain accurately. The parameters required for water intrusion calculation, such as the formation properties, geometry, and size of the water area, are usually derived through assumptions or inferences, resulting in significant uncertainty; ③ Dynamic data of the study area are difficult to obtain accurately. The dynamic parameters required for water intrusion calculation, such as the water intrusion constant, effective rock compressibility coefficient, and formation pressure, have certain errors compared to the actual situation. Moreover, it is impossible to shut down wells to test formation pressure at any time during actual gas field production; ④ The water intrusion calculation equations are complex and cumbersome, requiring a large amount of manpower and resources, and the results are highly uncertain; ⑤ Human subjective factors affect the accuracy of the calculation. Steps such as manually identifying charts and selecting regression points cause significant errors in the fitting results.

[0004] In order to at least partially solve the technical problems existing in the prior art, the inventors made this invention, which provides a method and apparatus for determining the water intrusion of a gas reservoir through specific embodiments. The method calculates the water intrusion of a gas reservoir based on pore volume. The calculation process is relatively simple and fast, requires fewer parameters and has fewer subjective human factors, and can calculate the water intrusion of a gas reservoir more accurately, reducing the uncertainty in the water intrusion calculation process.

[0005] In a first aspect, embodiments of the present invention provide a method for determining the water intrusion of a gas reservoir, comprising:

[0006] Determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data;

[0007] By using the water saturation distribution data at the specified time and the three-dimensional geological model of the gas reservoir, a dynamic model containing the porosity field and the water saturation field at the specified time is obtained.

[0008] Based on the lower limit of the effective porosity of the gas reservoir, effective grids are selected from the grids located between the original gas-water interface and the gas-water interface at the specified time in the dynamic model.

[0009] For each effective grid, the water intrusion amount is determined based on the grid's volume, porosity, and water saturation at the specified time. The water intrusion amount of the gas reservoir at the specified time is obtained from the water intrusion amount of each grid.

[0010] Secondly, embodiments of the present invention provide a device for determining the water intrusion rate of a gas reservoir, comprising:

[0011] The basic data determination module is used to determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data.

[0012] The dynamic model building module is used to obtain a dynamic model containing the porosity field and the water saturation field at the time by using the water saturation distribution data at the time and the three-dimensional geological model of the gas reservoir.

[0013] An effective grid screening module is used to screen effective grids from the grids located between the original gas-water interface and the gas-water interface at the time in the dynamic model, based on the lower limit of the effective porosity of the gas reservoir.

[0014] The water intrusion calculation module is used to determine the water intrusion amount for each effective grid based on the grid's volume, porosity, and water saturation at the specified time, and to obtain the water intrusion amount of the gas reservoir at the specified time from the water intrusion amount of each grid.

[0015] Thirdly, embodiments of the present invention provide a computer program product, including a computer program / instruction, wherein the computer program / instruction, when executed by a processor, implements the above-described method for determining the amount of water intrusion into a gas reservoir.

[0016] Fourthly, this disclosure provides a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described method for determining the amount of water intrusion into a gas reservoir.

[0017] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0018] (1) The method for determining water intrusion in gas reservoirs provided in this embodiment of the invention determines the original gas-water interface, the gas-water interface at a set time, and the water saturation distribution data of the gas reservoir, and obtains a dynamic model including the porosity field and the water saturation field at the set time. Based on the lower limit of effective porosity, effective grids are selected from the grids located between the original gas-water interface and the gas-water interface at the set time in the dynamic model. The water intrusion of each grid is calculated based on the grid volume, porosity, and water saturation at the set time, thus obtaining the water intrusion of the gas reservoir at the set time. This method uses a three-dimensional geological model to calculate the water intrusion of the gas reservoir based on the pore volume. The calculation process is fast and convenient, and it has universal operability. It has a wide range of applications, does not require assumptions or the establishment of manual maps, has high calculation accuracy, and is applicable to any type of gas reservoir. It provides a basis for the formulation of reasonable production allocation for single wells and reasonable production rates for gas reservoirs.

[0019] (2) The method for determining water intrusion in gas reservoirs provided in this embodiment of the invention requires static parameters, mainly the original gas-water interface and a three-dimensional geological model (including the porosity field), which can be predicted through refined three-dimensional geological modeling. In particular, the static parameters between wells are more reliable. It requires less dynamic data, mainly the gas-water interface and water saturation distribution data at a set time, which are easy to obtain. Furthermore, the dynamic data is relatively reliable; for example, the gas-water interface at a set time can be determined through historical gas production profile test data, reducing the impact of data uncertainty on the calculation results. Therefore, this method requires fewer parameters and involves fewer subjective human factors, allowing for more accurate calculation of water intrusion in gas reservoirs and reducing the uncertainty in the water intrusion calculation process.

[0020] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0021] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0023] Figure 1 This is a flowchart of the method for determining the water intrusion of a gas reservoir in Embodiment 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the gas reservoir water intrusion determination device in an embodiment of the present invention. Detailed Implementation

[0025] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0026] It should be understood that the terminology used herein is merely for describing particular embodiments and is not intended to limit the invention. Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0027] To address the limitations of existing water intrusion calculation methods, difficulties in accurately obtaining parameters, complex calculation processes, and large errors in calculation results, this invention provides a method and apparatus for determining water intrusion in gas reservoirs. This method is relatively simple and fast, requires fewer parameters, has fewer subjective human factors, can calculate water intrusion in gas reservoirs more accurately, reduces uncertainties in the water intrusion calculation process, and has a wide range of applications.

[0028] Example 1

[0029] Embodiment 1 of the present invention provides a method for determining the water intrusion of a gas reservoir, the process of which is as follows: Figure 1 As shown, it includes the following steps:

[0030] Step S11: Determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data.

[0031] (1) Determination of the original gas-water interface of the gas reservoir.

[0032] Determining the original gas-water interface of a gas reservoir can begin by obtaining resistivity curves, logging data, and test analysis data from wells drilled through the gas reservoir.

[0033] If a well drilled through a gas reservoir has neither logging data nor test analysis data, the resistivity curve in the gas reservoir will show a descending step, and the size of the step will reach a set scale. The depth at the boundary where the resistivity difference between shallow and deep reservoirs appears will be determined as the original gas-water boundary depth of the gas reservoir at that well. If a well drilled through a gas reservoir has logging and / or test analysis data, the original gas-water boundary depth of the gas reservoir at that well can be directly obtained based on the logging and / or test analysis data. Alternatively, the original gas-water boundary depth of the gas reservoir at that well can be determined by combining the resistivity curve, logging and test analysis data, and geological understanding.

[0034] After obtaining the original gas-water boundary depth at each well, the original gas-water interface of the gas reservoir is determined by comprehensively considering the original gas-water boundary depths of each well. The original gas-water interface is a horizontal plane, so it is sufficient to determine a uniform original gas-water boundary depth.

[0035] (2) Determination of the gas-water interface at the set time of the gas reservoir.

[0036] This can include establishing a gas-water two-phase interpretation model using well logging data of fluid density, water holdup, temperature, and pressure from gas production wells at a set time, to obtain the gas-water interface depth at the production wells; and applying a set interpolation algorithm to obtain the gas-water interface at a set time from the gas-water interface depths at each production well. The dynamic gas-water interface is no longer a plane but a curved surface; the gas-water interface distribution data obtained after interpolating the gas-water interface depths of each well is used as the gas-water interface.

[0037] Specifically, an interpolation algorithm can be set, such as the Kriging interpolation algorithm.

[0038] After obtaining the depth distribution data of the gas-water interface, a depth contour map of the gas-water interface can also be drawn.

[0039] (3) Determination of water saturation distribution data at a given time in the gas reservoir.

[0040] This can include calculating the water saturation of the gas reservoir at the production wells using the formation capture section curve in the saturation logging data at a set time; and applying a set interpolation algorithm to obtain the water saturation distribution data of the gas reservoir at a set time from the water saturation at each production well.

[0041] The interpolation algorithm can be either Kriging interpolation or other interpolation algorithms.

[0042] See Table 1 for the saturation logging interpretation results of well X-1:

[0043] Table 1. Saturation logging interpretation results of Well X-1

[0044]

[0045] Step S12: Using the water saturation distribution data at a set time and the three-dimensional geological model of the gas reservoir, obtain a dynamic model that includes the porosity field and the water saturation field at a set time.

[0046] This can include using data such as seismic, tectonic, stratigraphic, and well logging data to establish a three-dimensional geological network model of the gas reservoir, and using Gaussian sequential simulation stochastic algorithm to establish a dynamic model that includes the porosity field and the water saturation field at a set time using water saturation distribution data at a set time and the three-dimensional geological model of the gas reservoir.

[0047] Step S13: Based on the lower limit of the effective porosity of the gas reservoir, select effective grids from the grids located between the original gas-water interface and the gas-water interface at a set time in the dynamic model.

[0048] The lower limit of the effective porosity of a gas reservoir can be obtained through comprehensive geological understanding.

[0049] Step S14: For each effective grid, determine the water intrusion amount based on the grid's volume, porosity, and water saturation at a set time. The water intrusion amount of the gas reservoir at the set time is obtained from the water intrusion amount of each grid.

[0050] Based on the mesh volume, porosity, and water saturation at a given time, the water intrusion rate of the mesh at a given time is determined using the following formula:

[0051] W i =V i *φ i *S w =a i *b i *h i *φ i *S w

[0052] In the above formula, W i V represents the water intrusion amount at a given time for grid i. i and φ i a represents the volume and porosity of grid i, respectively. i b i and h i S represents the length, width, and height of grid i, respectively. w Let be the water saturation of grid i at a given time.

[0053] The method for determining water intrusion in gas reservoirs provided in Embodiment 1 of this invention determines the original gas-water interface, the gas-water interface at a set time, and the water saturation distribution data of the gas reservoir, obtaining a dynamic model including the porosity field and the water saturation field at the set time. Based on the lower limit of effective porosity, effective grids are selected from the grids located between the original gas-water interface and the gas-water interface at the set time in the dynamic model. The water intrusion of each grid is calculated based on the grid volume, porosity, and water saturation at the set time, thus obtaining the water intrusion of the gas reservoir at the set time. This method utilizes three-dimensional geological modeling tools to calculate the water intrusion of the gas reservoir based on pore volume. The calculation process is fast and convenient, with universal operability; it has a wide range of applications, requiring no assumptions or the creation of manual maps, and has high calculation accuracy, applicable to any type of gas reservoir; it provides a basis for the formulation of reasonable production allocation for single wells and reasonable production rates for gas reservoirs.

[0054] The static parameters required for the calculation mainly include the original gas-water interface and a three-dimensional geological model (including the porosity field), which can be predicted through refined three-dimensional geological modeling, especially the static parameters between wells, which are more reliable. The required dynamic data is minimal, mainly consisting of gas-water interface and water saturation distribution data at a set time point. These data are readily available and relatively reliable; for example, the gas-water interface at a set time point can be determined through historical gas production profile test data, reducing the impact of data uncertainty on the calculation results. Therefore, this method requires fewer parameters and involves fewer subjective human factors, allowing for more accurate calculation of water intrusion in gas reservoirs and reducing uncertainties in the water intrusion calculation process.

[0055] Example 2

[0056] Embodiment 2 of the present invention provides an application example of a method for determining water intrusion in a gas reservoir.

[0057] The XX gas reservoir, located within the Kelasu structural belt of the Tarim Basin, is a blocky, bottom-water dry gas reservoir in a faulted anticline discovered in 1998, characterized by abnormally high pressure and normal temperature. Development began in 2004, with a design target of water breakthrough in 2025 and a designed stable production period of 17 years. However, water breakthrough actually occurred in 2008, with an actual stable production period of only 3 years. The actual production differed significantly from the design, and the premature water breakthrough severely impacted the reservoir's recovery rate. By 2022, a total of 247 dynamic well tests and 194 production logging operations had been conducted on the entire reservoir, yielding abundant dynamic data that provides a foundation for a comprehensive understanding of water intrusion characteristics and patterns. The method provided in Example 1 of this invention for calculating the water intrusion volume of the XX gas reservoir is relatively accurate, consistent with previous dynamic assessments, and shows a high degree of agreement with actual conditions. The calculation results provide support for development strategies and engineering measures such as drainage, water control, and water shut-off.

[0058] Based on the inventive concept of this invention, embodiments of this invention also provide a device for determining the water intrusion of a gas reservoir, the structure of which is as follows: Figure 2 As shown, it includes:

[0059] The basic data determination module 21 is used to determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data.

[0060] The dynamic model building module 22 is used to obtain a dynamic model containing the porosity field and the water saturation field at the time by using the water saturation distribution data at the time and the three-dimensional geological model of the gas reservoir.

[0061] The effective grid screening module 23 is used to screen effective grids from the grids located between the original gas-water interface and the gas-water interface at the time in the dynamic model according to the lower limit of the effective porosity of the gas reservoir.

[0062] The water intrusion calculation module 24 is used to determine the water intrusion amount for each effective grid based on the grid's volume, porosity, and water saturation at the time, and to obtain the water intrusion amount of the gas reservoir at the time from the water intrusion amount of each grid.

[0063] In some embodiments, the basic data determination module 21 determines the original gas-water interface of the gas reservoir, specifically for:

[0064] Obtain the resistivity curves of the drilled gas reservoir wells. For each well, the depth at which the resistivity curve in the gas reservoir shows a descending step and the size of the step reaches a set size, and the boundary where the deep and shallow resistivity show a negative difference, is determined as the original gas-water interface depth of the gas reservoir at that well. The original gas-water interface of the gas reservoir is determined by comprehensively considering the original gas-water interface depths of each well.

[0065] In some embodiments, the basic data determination module 21 is further configured to:

[0066] If logging and / or test analysis data exist for a well that has been drilled through a gas reservoir, the original gas-water boundary depth of the gas reservoir at that well is determined based on the logging and / or test analysis data.

[0067] In some embodiments, the basic data determination module 21 determines the gas-water interface at a set time in the gas reservoir, specifically for:

[0068] By using the fluid density, water holdup, temperature, and pressure logging curves from the gas production profile logging data of the gas reservoir at a set time, a gas-water two-phase interpretation model is established to obtain the gas-water boundary depth of the gas reservoir at the production well. By applying a set interpolation algorithm, the gas-water interface of the gas reservoir at that time is obtained from the gas-water boundary depth of the gas reservoir at each production well.

[0069] In some embodiments, the basic data determination module 21 determines the water saturation distribution data of the gas reservoir at a set time, specifically for:

[0070] The water saturation of the gas reservoir at the production wells is calculated using the formation capture section curve in the saturation logging data at a set time. Then, using a predefined interpolation algorithm, the water saturation distribution data of the gas reservoir at each production well is obtained.

[0071] In some embodiments, the dynamic model building module 22 is specifically used for:

[0072] Using the water saturation distribution data at the specified time and the three-dimensional geological model of the gas reservoir, a dynamic model including the porosity field and the water saturation field at the specified time is established using a Gaussian sequential simulation stochastic algorithm.

[0073] In some embodiments, the water intrusion calculation module 24 determines the water intrusion amount based on the volume, porosity, and water saturation at the stated time, specifically for:

[0074] Based on the grid's volume, porosity, and water saturation at the stated time, the water intrusion amount of the grid at that time is determined using the following formula:

[0075] W i =V i *φ i *S w

[0076] In the above formula, W i Let V and φ be the water intrusion at time i. i S represents the volume and porosity of grid i, respectively. w Let be the water saturation of grid i at the given time.

[0077] Regarding the apparatus in the above embodiments, the specific manner in which each module performs its operation has been described in detail in the embodiments related to the method, and will not be elaborated upon here.

[0078] Based on the inventive concept of the present invention, embodiments of the present invention also provide a computer program product, including a computer program / instruction, wherein the computer program / instruction, when executed by a processor, implements the above-mentioned method for determining the amount of water intrusion into a gas reservoir.

[0079] Based on the inventive concept of this invention, this embodiment of the invention also provides a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the above-described method for determining the amount of water intrusion into a gas reservoir.

[0080] Unless otherwise specifically stated, terms such as processing, calculation, operation, determination, display, etc., may refer to the actions and / or processes of one or more processing or computing systems or similar devices that represent the manipulation and conversion of data representing physical (e.g., electronic) quantities within the registers or memory of the processing system into other data similarly representing physical quantities within the memory, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals can be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description can be represented by voltage, current, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0081] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to the specific order or hierarchy described.

[0082] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0083] Those skilled in the art will also understand that the various illustrative logic blocks, modules, circuits, and algorithm steps described in conjunction with the embodiments herein can be implemented as electronic hardware, computer software, or a combination thereof. To clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described in terms of their functionality. Whether such functionality is implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in alternative ways for each specific application; however, such implementation decisions should not be construed as departing from the scope of this disclosure.

[0084] The steps of the methods or algorithms described in conjunction with the embodiments herein can be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules can reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and storage medium can reside in an ASIC. The ASIC can reside in a user terminal. Alternatively, the processor and storage medium can exist as discrete components in the user terminal.

[0085] For software implementation, the techniques described in this application can be implemented using modules (e.g., procedures, functions, etc.) that perform the functions described in this application. This software code can be stored in memory units and executed by a processor. The memory units can be implemented within the processor or outside the processor; in the latter case, they are communicatively coupled to the processor via various means, as is well known in the art.

[0086] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A method for determining water influx in a gas reservoir, the method comprising: include: Determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data; By using the water saturation distribution data at the specified time and the three-dimensional geological model of the gas reservoir, a dynamic model containing the porosity field and the water saturation field at the specified time is obtained. Based on the lower limit of the effective porosity of the gas reservoir, effective grids are selected from the grids located between the original gas-water interface and the gas-water interface at the specified time in the dynamic model. For each effective grid, the water intrusion is determined based on the grid's volume, porosity, and water saturation at the specified time. The water intrusion of the gas reservoir at the specified time is obtained from the water intrusion of each grid. The determination of water intrusion includes determining the water intrusion of the grid at that time using the following formula: ； In the above formula, Let i be the amount of water intrusion at that time. and Let i be the volume and porosity of grid i, respectively. Let be the water saturation of grid i at the given time.

2. The method as described in claim 1, characterized in that, The determination of the original gas-water interface of the gas reservoir specifically includes: Obtain the resistivity curve of the well drilled through the gas reservoir. For each well, the depth at which the resistivity curve in the gas reservoir shows a descending step and the size of the step reaches a set size, and the boundary where the deep and shallow resistivity show a negative difference, is determined as the original gas-water boundary depth of the gas reservoir at that well. The original gas-water interface of the gas reservoir is determined by comprehensively considering the original gas-water boundary depth of each well.

3. The method as described in claim 2, characterized in that, Also includes: If logging and / or test analysis data exist for a well that has been drilled through a gas reservoir, the original gas-water boundary depth of the gas reservoir at that well is determined based on the logging and / or test analysis data.

4. The method as described in claim 1, characterized in that, Determining the gas-water interface at a given time in a gas reservoir specifically includes: By using the fluid density, water holdup, temperature and pressure logging curves from the gas production profile logging data at a set time of the gas reservoir production well, a gas-water two-phase interpretation model is established to obtain the gas-water boundary depth of the gas reservoir at the production well. By applying a predefined interpolation algorithm, the gas-water interface of the gas reservoir at a given time is obtained from the gas-water boundary depth at each production well.

5. The method as described in claim 1, characterized in that, Determine the water saturation distribution data of the gas reservoir at a set time, specifically including: The water saturation of the gas reservoir at the production well is calculated using the formation capture section curve in the saturation logging data at a set time of the gas reservoir production well. By applying a predefined interpolation algorithm, the water saturation distribution data of the gas reservoir at a given time are obtained from the water saturation at each production well.

6. The method as described in claim 1, characterized in that, The process of obtaining a dynamic model containing the porosity field and the water saturation field at the specified time using the water saturation distribution data at the specified time and the three-dimensional geological model of the gas reservoir specifically includes: Using the water saturation distribution data at the specified time and the three-dimensional geological model of the gas reservoir, a dynamic model including the porosity field and the water saturation field at the specified time is established using a Gaussian sequential simulation stochastic algorithm.

7. A device for determining the water intrusion volume of a gas reservoir, characterized in that, include: The basic data determination module is used to determine the original gas-water interface of the gas reservoir, the gas-water interface at a set time, and the water saturation distribution data. The dynamic model building module is used to obtain a dynamic model containing the porosity field and the water saturation field at the time by using the water saturation distribution data at the time and the three-dimensional geological model of the gas reservoir. An effective grid screening module is used to screen effective grids from the grids located between the original gas-water interface and the gas-water interface at the time in the dynamic model, based on the lower limit of the effective porosity of the gas reservoir. The water intrusion calculation module is used to determine the water intrusion amount for each effective grid based on the grid's volume, porosity, and water saturation at the specified time. The water intrusion amount of the gas reservoir at the specified time is obtained from the water intrusion amount of each grid. Specifically, determining the water intrusion amount is done using the following formula: ； In the above formula, Let i be the amount of water intrusion at that time. and Let i be the volume and porosity of grid i, respectively. Let be the water saturation of grid i at the given time.

8. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instruction is executed by the processor, it implements the method for determining the water intrusion of a gas reservoir as described in any one of claims 1 to 6.

9. A server, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the method for determining the amount of water intrusion into a gas reservoir as described in any one of claims 1 to 6.

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