Carbonate rock gas field gas well productivity evaluation method, device and equipment

Abstract

The invention relates to the technical field of oil-gas exploration and development, in particular to a gas well productivity evaluation method, device and equipment for a carbonate rock gas field. Comprising the following steps: drawing a relation chart between different coefficients by collecting historical data in special test wells of different types of carbonate gas field gas wells, classifying the carbonate gas field gas wells according to the drawn relation chart and different characteristics of reservoir stratums, and fitting coefficient relational expressions of the different types of gas field gas wells; and judging the type of the gas well to be subjected to productivity evaluation according to the logging data of the gas well to be subjected to productivity evaluation, and generating productivity evaluation of the gas well to be subjected to productivity evaluation. Therefore, on the premise that productivity well testing is not carried out, effective evaluation of the gas well productivity is achieved through an empirical formula and field test data, adverse factors of productivity well testing can be effectively reduced, and the coverage rate of gas well productivity evaluation is increased.

Description

Technical Field

[0001] This manual belongs to the field of oil and gas exploration and development technology, and in particular relates to a method, apparatus and equipment for evaluating the production capacity of gas wells in carbonate gas fields. Background Technology

[0002] Carbonate gas fields are one of the important areas of natural gas exploration and development in China. As of the end of 2018, carbonate gas fields accounted for 28.34% of the proven reserves of natural gas fields, and 66% of conventional gas production in 2018 came from carbonate gas fields. Low permeability is a typical characteristic of the carbonate gas reservoirs discovered in recent years.

[0003] Determine the absolute unobstructed flow rate q of the gas well AOF It is the core work of gas field development, running through the entire process, and includes the q in the early evaluation stage. AOF The evaluation results serve as the basis for the design of gas production and surface gathering and transportation projects. The reliability of the evaluation results determines the rationality of the project design and investment, as well as the q during the stable production and decline periods. AOF The evaluation results serve as the basis for optimizing and adjusting gas field production. (Carbonate gas field q) AOF Yes, the determination is based on the production capacity testing technology based on seepage mechanics. Production capacity testing was initially a multi-point testing method. After decades of field practice, with the deepening of concepts such as resource protection, environmental protection, safety, and improved management efficiency, the field implementation of production capacity evaluation and gas well production determination has increasingly relied on and adopted the single-point testing method. Since the publication of the "one-point method" formula based on the binomial production capacity equation theory in 1989, this method has gradually become the main method of single-point testing in the field because it combines theory, experience, and convenience. Various gas fields have successively established a large number of empirical formulas for single-point testing production capacity evaluation.

[0004] Carbonate gas fields are generally characterized by dense matrix, well-developed fractures, and strong heterogeneity. With the continuous practice of single-point testing in the field, gas wells with low permeability, strong heterogeneity, and medium-to-high permeability geological characteristics present a contradiction in the productivity evaluation process compared to the "one-point method." If the reservoir has strong permeability, the stability empirical number in the "one-point method" formula is less than 0.25. For this type of gas reservoir, the productivity evaluation results of single-point testing under small production pressure differentials will be magnified many times over, rendering the "one-point method" completely inapplicable. The above problems can be addressed by summarizing and simplifying the "one-point method" productivity equation based on obtaining relatively reliable productivity test results in specific blocks. If the gas reservoir has complex relationships between pores, cavities, and fractures at different scales, exhibiting low permeability and strong heterogeneity, and the permeability of each well area differs by orders of magnitude after reservoir stimulation, the single-point test results cannot reflect the true stable permeability potential. For this type of gas reservoir, field testing is insufficient to meet the requirements of natural gas well testing technology. In addition, well testing in deep to ultra-deep carbonate gas fields carries high risks, and the universality of the extended "one-point method" for finely classifying reservoir types based on dynamic and static data is also limited.

[0005] Therefore, how to evaluate the production capacity of gas wells in carbonate gas fields and how to accurately classify reservoir types based on dynamic and static data are technical problems that urgently need to be solved. Summary of the Invention

[0006] To address the difficulty in re-identifying high-consequence zones in existing technologies, this specification provides a method, apparatus, and equipment for evaluating the production capacity of gas wells in carbonate gas fields. To overcome the issue of low reliability in production capacity evaluation results for low-permeability, highly heterogeneous, and medium-to-high-permeability reservoirs using conventional "single-point methods," a simple method for calculating stable production capacity based on well logging data is proposed, and the quantitative relationship between stable production capacity of carbonate gas wells and well logging formation coefficients and storage coefficients is described. This specification establishes a method for calculating the stable production capacity q of gas wells based on well logging Kh and φh. AOF The method clarifies the characteristics of different reservoir types and the upper and lower boundaries of gas well stability q. AOF The mathematical expression for .

[0007] The specific technical solutions of the embodiments in this specification are as follows:

[0008] On the one hand, the embodiments of this specification provide a method for evaluating the production capacity of gas wells in carbonate gas fields, the method comprising:

[0009] Obtain historical logging data of gas wells in various types of carbonate gas fields, and obtain the formation coefficient and energy storage coefficient of the well logging based on the historical logging data;

[0010] The coefficients of the binomial productivity equation were obtained based on the historical well logging data.

[0011] Draw a first relationship chart between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship chart between the well test logging storage coefficient and the well test logging formation coefficient;

[0012] Based on the distinguishing features of the first relationship map and the second relationship map, the gas wells in the carbonate gas field are classified.

[0013] Based on the classification results, the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation are fitted respectively;

[0014] Obtain logging data for a gas well awaiting production capacity evaluation, including logging formation coefficient and logging storage coefficient, and conduct a pre-production static pressure test on the gas well awaiting production capacity evaluation to obtain its original formation pressure;

[0015] Based on the logging data of the gas well to be evaluated for production capacity, determine its corresponding type, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated for production capacity to determine the binomial production capacity equation coefficient of the gas well to be evaluated for production capacity.

[0016] Substitute the coefficients of the binomial production capacity equation of the gas well to be evaluated and its original formation pressure into the gas field's gas well production capacity calculation formula to generate the production capacity evaluation of the gas well to be evaluated.

[0017] Furthermore, the binomial productivity equation coefficient expression obtained based on the aforementioned well logging historical data further includes the following expressions:

[0018]

[0019] In the formula, A represents the Darcy seepage term coefficient for stable gas wells, in MPa. 2 / (10 4 m 3 / d); B represents the coefficient of the stable non-Darcy seepage term of the gas well, MPa 2 / (10 4 m 3 / d) 2 K represents the gas reservoir permeability, 10 -3 μm 2 h represents reservoir thickness (m); T represents temperature (K); μ g The gas viscosity is given by Z (mPa·s); Z represents the deviation factor (dimensionless); r represents the well radius (m); S represents the skin factor (dimensionless); and D represents the non-Darcy flow coefficient (m). 3 / d) -1 The subscript w indicates the wellbore, and e indicates the venting zone.

[0020] Furthermore, the first relationship chart plotting the relationship between the well logging formation coefficient and the well logging history data further includes the following: The first relationship chart is represented as follows:

[0021] A = a(Kh) b ,

[0022] B = a'(Kh) b ',

[0023] In the formula, A and B are empirical stability numbers for gas wells, dimensionless; Kh is the formation coefficient from gas well logging, 10 -3 μm 2 ·m, a, a', b, b' are empirical numbers for fitting, and are dimensionless.

[0024] Furthermore, the second relationship chart between the logging storage coefficient and the logging formation coefficient further includes the following: the second relationship chart is represented as follows:

[0025] Kh = c(φh) 2 +d(φh),

[0026] In the formula, c and d are empirical numbers that are dimensionless; φh is the well logging energy storage coefficient, in meters.

[0027] Furthermore, conducting pre-production static pressure testing on the gas wells to be evaluated for production capacity further includes,

[0028] The stopping point depth and pressure data in the wellbore of the gas well to be evaluated for production capacity are recorded by a pressure gauge, and the stopping point depth is converted into the stopping point vertical depth.

[0029] Based on the pressure gradient of the last two stopping points of the wellbore fitted with the vertical depth of the stopping point, the pressure in the middle of the producing layer of the gas well to be evaluated for production capacity is calculated based on the pressure gradient and recorded as the original formation pressure.

[0030] Furthermore, the pressure gradient of the last two stopping points of the wellbore, fitted according to the vertical depth of the stopping point, further includes,

[0031] The gas wellbore under production capacity evaluation has n stopping points. The vertical depth of the (n-1)th stopping point is denoted as H1, the vertical depth of the nth stopping point is denoted as H2, the pressure of the (n-1)th stopping point is denoted as p1, and the pressure of the nth stopping point is denoted as p2. The pressure gradient is calculated using the following formula:

[0032]

[0033] In the formula, Δp is the pressure gradient, MPa / m; H1 is the vertical depth of the (n-1)th stop point, m; H2 is the vertical depth of the nth stop point, m; p1 is the pressure gradient of the (n-1)th stop point, and p2 is the pressure of the nth stop point.

[0034] Furthermore, the calculation of the pressure in the middle of the producing formation of the gas well to be evaluated based on the pressure gradient, denoted as the original formation pressure, further includes...

[0035] The formula for calculating the pressure in the middle of the gas well producing zone is as follows:

[0036] p = p² + (H - H²)Δp

[0037] In the formula, p is the pressure in the middle of the gas well producing zone, MPa; p2 is the pressure at the nth stopping point, MPa; H is the vertical depth in the middle of the gas well producing zone, m; H2 is the vertical depth at the nth stopping point, m; Δp is the pressure gradient, MPa / m.

[0038] Furthermore, substituting the well logging formation coefficients into the first relational expression corresponding to the type of gas well to be evaluated for production capacity further includes,

[0039] If the logging data of the gas well to be evaluated for production capacity is missing the logging formation coefficient, then according to the classification results, the second relationship between the logging storage coefficient and the logging formation coefficient of different types of well tests will be fitted respectively.

[0040] Substituting the well logging storage coefficient of the gas well to be evaluated for production capacity into the second formula, the well logging formation coefficient of the gas well to be evaluated for production capacity is obtained.

[0041] Furthermore, the formula for calculating the gas well productivity of the gas field is as follows:

[0042]

[0043] In the formula, q AOF Indicates a stable, absolutely unobstructed flow rate at the gas well; P R This represents the original formation pressure.

[0044] On the other hand, embodiments of this specification also provide a device for evaluating the production capacity of gas wells in carbonate gas fields, the device comprising:

[0045] The historical data processing module is used to acquire historical well logging data of gas wells in various types of carbonate gas fields, and to obtain well logging formation coefficient and well logging energy storage coefficient based on the historical well logging data.

[0046] The coefficients of the binomial productivity equation were obtained based on the historical well logging data.

[0047] The relationship diagram drawing module is used to draw a first relationship diagram between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship diagram between the well test logging energy storage coefficient and the well test logging formation coefficient;

[0048] The gas field and gas well classification module is used to classify the gas wells of the carbonate gas field according to the distinguishing features of the first relationship map and the second relationship map;

[0049] The coefficient relationship fitting module is used to fit the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation based on the classification results.

[0050] The gas well static pressure test module is used to acquire logging data of a gas well to be evaluated for production capacity, including logging formation coefficient and logging storage coefficient, and to conduct a pre-production static pressure test on the gas well to be evaluated for production capacity to obtain its original formation pressure.

[0051] The production capacity coefficient acquisition module is used to determine the type of the gas well to be evaluated based on the logging data, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated to determine the binomial production capacity equation coefficient of the gas well to be evaluated.

[0052] The gas well productivity evaluation module is used to substitute the coefficients of the binomial productivity equation of the gas well to be evaluated and its original formation pressure into the gas field gas well productivity calculation formula to generate the productivity evaluation of the gas well to be evaluated.

[0053] On the other hand, embodiments of this specification also provide a computer device, including a memory, a processor, and a computer program stored in the memory, wherein the processor executes the computer program to implement the above-described method.

[0054] On the other hand, embodiments of this specification also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0055] Finally, this specification also provides a computer program product, which includes a computer program that, when executed by a processor, implements the above-described method.

[0056] Using the embodiments of this specification, firstly, well logging formation coefficients and well logging storage coefficients from special well tests of different types of carbonate gas fields are collected. Simultaneously, the coefficient relationships in the binomial productivity calculation equation are obtained based on the special well test data. Then, by plotting the relationship between the well logging formation coefficient and historical well logging data, as well as the relationship between the well logging storage coefficient and the well logging formation coefficient, a first relationship chart and a second relationship chart are generated. Based on the plotted relationship charts and the different reservoir characteristics, carbonate gas field wells are classified into various types of carbonate gas fields. Then, based on the classification results, the well logging historical data of gas wells in different categories of gas fields are fitted to obtain the coefficient relationships of the binomial productivity equation and the relationship between the well logging storage coefficient and the well logging formation coefficient. The process involves several steps: First, establishing a well formation coefficient relationship. This involves acquiring logging data from a gas well awaiting production capacity evaluation, obtaining its formation coefficient and storage coefficient, conducting a pre-production static pressure test, recording and interpreting the pressure data, and calculating the original formation pressure. Based on the logging data, the well's type is determined. The formation coefficient is then substituted into the corresponding historical logging data to obtain a binomial production capacity equation coefficient relationship. This yields the binomial production capacity equation coefficients for the well. Finally, the binomial production capacity equation coefficients and the original formation pressure are substituted into the binomial production capacity calculation formula to generate the production capacity evaluation for the well. This method allows for effective evaluation of gas well production capacity without conducting production well tests, using empirical formulas and field test data. It effectively reduces the adverse factors of production well tests and improves the coverage of gas well production capacity evaluation. It can also reduce the waste of resources caused by releasing large amounts of sulfur-containing natural gas during production testing of sulfur-containing gas wells, and reduce the risks of on-site testing operations and safety management. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 The figure shown is a schematic diagram of the implementation system of a method for evaluating the production capacity of gas wells in a carbonate gas field according to an embodiment of this specification;

[0059] Figure 2 The diagram shown is a flowchart illustrating a method for evaluating the production capacity of gas wells in a carbonate gas field, as described in this specification.

[0060] Figure 3The diagram shown is a flowchart illustrating the pre-production static pressure test of the gas well to be evaluated for production capacity in an embodiment of this specification.

[0061] Figure 4 The diagram shown is a structural schematic of a carbonate gas field well productivity evaluation device according to an embodiment of this specification.

[0062] Figure 5 The diagram shown is a structural schematic of the computer device in an embodiment of this specification.

[0063] [Explanation of Figure Markers]:

[0064] 101. Terminal;

[0065] 102. Server;

[0066] 401. Historical Data Processing Module;

[0067] 402. Relationship Diagram Drawing Module;

[0068] 403. Gas Field and Gas Well Classification Module;

[0069] 404, Coefficient Relationship Fitting Module;

[0070] 405. Gas Well Static Pressure Testing Module;

[0071] 406. Capacity Coefficient Acquisition Module;

[0072] 407. Gas Well Productivity Evaluation Module;

[0073] 502. Computer equipment;

[0074] 504. Processing equipment;

[0075] 506. Storage resources;

[0076] 508. Drive system;

[0077] 510. Input / output module;

[0078] 512. Input devices;

[0079] 514. Output devices;

[0080] 516. Presentation equipment;

[0081] 518. Graphical User Interface;

[0082] 520. Network interface;

[0083] 522. Communication link;

[0084] 524. Communication bus. Detailed Implementation

[0085] The technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the embodiments of this specification, and not all embodiments. Based on the embodiments of this specification, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the embodiments of this specification.

[0086] It should be noted that the terms "first," "second," etc., in the description, claims, and accompanying drawings of the embodiments herein are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, apparatus, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0087] It should be noted that the acquisition, storage, use, and processing of data in the technical solutions of the embodiments of this specification all comply with the relevant provisions of national laws and regulations.

[0088] It should be noted that in the embodiments of this specification, certain software, components, models and other existing solutions in the industry may be mentioned. These should be regarded as exemplary and are only intended to illustrate the feasibility of implementing the technical solution of this application. However, they do not mean that the applicant has used or necessarily used the solution.

[0089] like Figure 1 The diagram illustrates an implementation system for a method for evaluating the productivity of gas wells in a carbonate gas field, as described in this specification. The system includes a terminal 101 and a server 102. The terminal 101 and server 102 can communicate via a network, which may include a local area network (LAN), a wide area network (WAN), the Internet, or a combination thereof, and is connected to a website, user equipment (e.g., computing devices), and a backend system.

[0090] The project manager can input historical logging data from various types of carbonate gas field wells into server 102 via terminal 101. Server 102 performs production capacity evaluation on the wells based on the historical logging data and the logging data of the wells to be evaluated, and displays the evaluation results to the project manager via terminal 101. Optionally, server 102 can be a node in a cloud computing system (not shown in the figure), or each server can be a separate cloud computing system, including multiple computers interconnected by a network and operating as a distributed processing system.

[0091] In addition, it should be noted that, Figure 1 The examples shown are merely one application environment provided by the embodiments in this specification. In practical applications, other application environments may also be included, and this specification does not impose any limitations.

[0092] To address the problems existing in the prior art, this specification provides a method for evaluating the production capacity of gas wells in carbonate gas fields. By determining the type of the gas well to be evaluated, and substituting the coefficients of the binomial production capacity equation of the well and its original formation pressure into the binomial production capacity calculation formula appropriate for that type of gas well, the production capacity evaluation result of the gas well to be evaluated is determined. This method enables the precise classification of reservoir types and the evaluation of gas well production capacity in carbonate gas fields based on dynamic and static data. Figure 2 The diagram shown is a flowchart illustrating the method for evaluating the production capacity of gas wells in carbonate gas fields, as described in this specification. The process of evaluating the production capacity of gas wells in carbonate gas fields is illustrated in this diagram. The order of steps listed in the embodiments is merely one possible execution order among many steps and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiments or accompanying drawings can be executed sequentially or in parallel.

[0093] As shown in the figure, the method may include:

[0094] Step 201: Obtain historical logging data of gas wells in various types of carbonate gas fields, and obtain the formation coefficient and energy storage coefficient of the well logging based on the historical logging data;

[0095] The coefficients of the binomial productivity equation were obtained based on the historical well logging data.

[0096] Step 202: Draw a first relationship chart between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship chart between the well test logging storage coefficient and the well test logging formation coefficient;

[0097] Step 203: Classify the gas wells in the carbonate gas field according to the distinguishing features of the first relationship map and the second relationship map;

[0098] Step 204: Based on the classification results, fit the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation;

[0099] Step 205: Obtain logging data of a gas well to be evaluated for production capacity, including logging formation coefficient and logging storage coefficient, and conduct a pre-production static pressure test on the gas well to be evaluated for production capacity to obtain its original formation pressure;

[0100] Step 206: Determine the type of the gas well to be evaluated based on the logging data, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated to determine the binomial productivity equation coefficient of the gas well to be evaluated.

[0101] Step 207: Substitute the coefficients of the binomial production capacity equation of the gas well to be evaluated and its original formation pressure into the gas field gas well production capacity calculation formula to generate the production capacity evaluation of the gas well to be evaluated.

[0102] Using the embodiments of this specification, firstly, well logging formation coefficients and well logging storage coefficients from special well tests of different types of carbonate gas fields are collected. Simultaneously, the coefficient relationships in the binomial productivity calculation equation are obtained based on the special well test data. Then, by plotting the relationship between the well logging formation coefficient and historical well logging data, as well as the relationship between the well logging storage coefficient and the well logging formation coefficient, a first relationship chart and a second relationship chart are generated. Based on the plotted relationship charts and the different reservoir characteristics, carbonate gas field wells are classified into various types of carbonate gas fields. Then, based on the classification results, the well logging historical data of gas wells in different categories of gas fields are fitted to obtain the coefficient relationships of the binomial productivity equation and the relationship between the well logging storage coefficient and the well logging formation coefficient. The process involves several steps: First, establishing a coefficient relationship. This involves acquiring logging data for a gas well requiring production capacity evaluation. This includes obtaining the formation coefficient and storage coefficient, conducting a pre-production static pressure test, recording and interpreting the pressure data, and calculating the original formation pressure. Based on the logging data, the well's type is determined. The formation coefficient is then substituted into the corresponding historical logging data to obtain a binomial production capacity equation coefficient relationship. This yields the binomial production capacity equation coefficients for the well. Finally, the binomial production capacity equation coefficients and the original formation pressure are substituted into the binomial production capacity calculation formula for the well's type to generate a production capacity evaluation. This method allows for effective evaluation of gas well production capacity without conducting production well tests, using empirical formulas and field test data. It effectively reduces the adverse factors of production well tests and improves the coverage of gas well production capacity evaluation. It can also reduce the waste of resources caused by releasing large amounts of sulfur-containing natural gas during production testing of sulfur-containing gas wells, and reduce the risks of on-site testing operations and safety management.

[0103] In the embodiments of this specification, the production capacity of the gas well to be evaluated is carried out by substituting the coefficients of the binomial production capacity equation and its original formation pressure into the corresponding binomial gas well production capacity calculation formula. This method is applicable not only to the traditional "one-point method" but also to gas fields with low permeability, strong heterogeneity, and medium-to-high permeability geological characteristics. The establishment of this method overcomes the shortcomings of single-point testing in determining the stable production capacity of gas wells under specific geological conditions, revealing that reliable production capacity evaluation results should refer to both geological characteristics and the "one-point method" production capacity evaluation. This has positive significance for the development design and scale adjustment of carbonate gas fields.

[0104] In this embodiment of the specification, obtaining the binomial productivity equation coefficient expression based on the well logging history data further includes the following expressions:

[0105]

[0106] In the formula, A represents the Darcy seepage term coefficient for stable gas wells, in MPa. 2 / (10 4 m 3 / d); B represents the coefficient of the stable non-Darcy seepage term of the gas well, MPa 2 / (10 4 m 3 / d) 2 K represents the gas reservoir permeability, 10 -3 μm 2 h represents reservoir thickness (m); T represents temperature (K); μ g The gas viscosity is given by Z (mPa·s); Z represents the deviation factor (dimensionless); r represents the well radius (m); S represents the skin factor (dimensionless); and D represents the non-Darcy flow coefficient (m). 3 / d) -1 The subscript w indicates the wellbore, and e indicates the venting zone.

[0107] Specifically, the coefficients A and B in the binomial productivity equation are determined by fitting productivity test data from specialized well tests. The binomial productivity equation coefficients include the stable Darcy flow term coefficients and the stable non-Darcy flow term coefficients for gas wells, with the following expressions: In the formula, A represents the Darcy seepage term coefficient for stable gas wells, in MPa. 2 / (10 4 m 3 / d); B represents the coefficient of the stable non-Darcy seepage term of the gas well, MPa 2 / (10 4 m 3 / d) 2K represents the gas reservoir permeability, 10 -3 μm 2 h represents reservoir thickness (m); T represents temperature (K); μ g The gas viscosity is given by Z (mPa·s); Z represents the deviation factor (dimensionless); r represents the well radius (m); S represents the skin factor (dimensionless); and D represents the non-Darcy flow coefficient (m). 3 / d) -1 The subscript w indicates the wellbore, and e indicates the venting zone.

[0108] In this embodiment of the specification, the first relationship chart for plotting the relationship between the well logging formation coefficient and the well logging history data further includes the following: The first relationship chart is represented as follows:

[0109] A = a(Kh) b ,

[0110] B = a'(Kh) b ',

[0111] In the formula, A and B are empirical stability numbers for gas wells, dimensionless; Kh is the formation coefficient from gas well logging, 10 -3 μm 2 ·m, a, a', b, b' are empirical numbers for fitting, and are dimensionless.

[0112] Specifically, the general form of the empirical formula for fitting the relationship between well logging formation coefficients and well logging history data coefficients A and B on the chart is: A = a(Kh) b B = a'(Kh) b' In the formula, A and B are empirical stability numbers for gas wells, dimensionless; Kh is the formation coefficient from gas well logging, 10 -3 μm 2 ·m, a, a', b, b' are empirical numbers for fitting, and are dimensionless.

[0113] In this embodiment of the specification, the second relationship chart between the logging storage coefficient and the logging formation coefficient further includes, as shown in the second relationship chart:

[0114] Kh = c(φh) 2 +d(φh),

[0115] In the formula, c and d are empirical numbers that are dimensionless; φh is the well logging energy storage coefficient, in m.

[0116] In the embodiments of this specification, in order to obtain the original formation pressure of the gas well, such as Figure 3 As shown, conducting pre-production static pressure testing on the gas wells to be evaluated for production capacity further includes,

[0117] Step 301: Record the stopping point depth and pressure data in the wellbore of the gas well to be evaluated for production capacity using a pressure gauge, and convert the stopping point depth into the stopping point vertical depth;

[0118] Step 302: Fit the pressure gradient of the last two stopping points of the wellbore based on the vertical depth of the stopping point, and calculate the pressure in the middle of the producing layer of the gas well to be evaluated for production capacity based on the pressure gradient, and record it as the original formation pressure.

[0119] The method of fitting the pressure gradient of the last two stopping points of the wellbore based on the vertical depth of the stopping point further includes...

[0120] The gas wellbore under production capacity evaluation has n stopping points. The vertical depth of the (n-1)th stopping point is denoted as H1, the vertical depth of the nth stopping point is denoted as H2, the pressure of the (n-1)th stopping point is denoted as p1, and the pressure of the nth stopping point is denoted as p2. The pressure gradient is calculated using the following formula:

[0121]

[0122] In the formula, Δp is the pressure gradient, MPa / m; H1 is the vertical depth of the (n-1)th stop point, m; H2 is the vertical depth of the nth stop point, m; p1 is the pressure gradient of the (n-1)th stop point, and p2 is the pressure of the nth stop point.

[0123] In step 206, the static pressure test specifically refers to recording the stopping point depth and pressure data in the gas wellbore through the pressure gauge in the well test, converting the stopping point depth to the stopping point vertical depth, fitting the pressure gradient of the last two stopping points in the wellbore, and calculating the pressure in the middle of the gas well producing layer. This pressure is the original formation pressure.

[0124] The conversion of the stopping point depth to the stopping point vertical depth specifically refers to converting the stopping point depth to the stopping point vertical depth using well inclination data.

[0125] For example, there are 5 stopping points in the gas well shaft. The vertical depth of the 4th stopping point is denoted as H1, the vertical depth of the 5th stopping point is denoted as H2, the pressure of the 4th stopping point is denoted as p1, the pressure of the 5th stopping point is denoted as p2, and the pressure gradient is calculated by formula.

[0126]

[0127] In the formula, Δp is the pressure gradient, MPa / m; H1 is the vertical depth of the 4th stop point, m; H2 is the vertical depth of the 5th stop point, m; p1 is the pressure gradient of the 4th stop point, and p2 is the pressure gradient of the 5th stop point.

[0128] In the embodiments of this specification, calculating the pressure in the middle of the producing formation of the gas well to be evaluated based on the pressure gradient, denoted as the original formation pressure, further includes...

[0129] The formula for calculating the pressure in the middle of the gas well producing zone is as follows:

[0130] p = p² + (H - H²)Δp

[0131] In the formula, p is the pressure in the middle of the gas well producing zone, MPa; p2 is the pressure at the nth stopping point, MPa; H is the vertical depth in the middle of the gas well producing zone, m; H2 is the vertical depth at the nth stopping point, m; Δp is the pressure gradient, MPa / m.

[0132] In the embodiments of this specification, there may be situations where the logging data of a gas well awaiting production capacity evaluation lacks logging formation coefficients. Therefore, the logging formation coefficients are further substituted into the first relational expression corresponding to the type of the gas well awaiting production capacity evaluation.

[0133] If the logging data of the gas well to be evaluated for production capacity is missing the logging formation coefficient, then according to the classification results, the second relationship between the logging storage coefficient and the logging formation coefficient of different types of well tests will be fitted respectively.

[0134] Substituting the well logging storage coefficient of the gas well to be evaluated for production capacity into the second formula, the well logging formation coefficient of the gas well to be evaluated for production capacity is obtained.

[0135] Finally, the coefficients of the binomial productivity equation and the original formation pressure of the gas well to be evaluated are substituted into the gas field's gas well productivity calculation formula to generate the productivity evaluation of the gas well to be evaluated. The gas field's gas well productivity calculation formula is as follows:

[0136]

[0137] In the formula, q AOF This indicates a stable, absolutely unobstructed flow rate from the gas well, 10 4 m 3 / d.

[0138] In the embodiments of this specification, the method of substituting the coefficients of the binomial productivity equation of the gas well to be evaluated and its original formation pressure into the binomial gas well productivity calculation formula to evaluate the gas well productivity is applicable to the traditional "one-point method" and is also applicable to gas fields with low permeability, strong heterogeneity, and medium-to-high permeability geological characteristics. The establishment of this method compensates for the large error in determining the stable productivity of a gas well under specific geological conditions through single-point testing. It reveals that reliable productivity evaluation results should refer to both geological characteristics and the "one-point method" productivity evaluation, which has positive significance for the development design and scale adjustment of carbonate gas fields. Furthermore, the embodiments of this specification can achieve effective evaluation of gas well productivity through empirical formulas and field test data without conducting productivity well tests. The method can effectively reduce the adverse factors of productivity well testing and improve the coverage of gas well productivity evaluation.

[0139] For example, the gas well stability q established using the method of this specification AOF Based on the calculation method, example calculations were performed on different types of gas wells to verify the reliability of the method, and the applicability and limitations of the method were discussed. Before verifying the method, q was first clarified. AOF Verification principle: For wells with good applicability of the conventional "one-point method" (stable empirical number is close to 0.25 and oil test is stable), the results of this method are directly compared with the results of the conventional "one-point method"; for gas wells with a stable empirical number less than 0.25, this method is compared with the results of production capacity testing; (3) For strongly heterogeneous reservoirs (such as fracture-vuggy type II, pore-vuggy type I), the production capacity testing cannot obtain ideal results, so the evaluation results of this method are compared with the actual production effect of the gas well.

[0140] Verification results comparison: The average stable empirical number of the gas field is 0.23, indicating good applicability of the conventional "one-point method". Eleven gas wells were selected for production capacity evaluation results comparison (Table 1). The table shows that 8 out of the 11 gas wells showed good evaluation results using the logging Kh method, consistent with the calculation results of the "one-point method", with relative errors ranging from 2.23% to 50.05%, averaging 29.6%. The production capacity evaluation results of the "one-point method" are basically within the production capacity range calculated by the logging φh method. If the type is III, the lower limit is more reliable; if the type is I, the upper limit is more reliable.

[0141] Table 1 Comparison of Gas Field Production Capacity Evaluation Results

[0142]

[0143] The average stable empirical numbers for the second and third gas fields are 0.04, 0.05, and 0.15, respectively. The results calculated using the conventional "single-point method" are significantly higher than those from production testing. Four gas wells were selected for production capacity evaluation and comparison (Table 2). The table shows that the evaluation results obtained using this method are better, solving the problem of the conventional "single-point method" amplifying production capacity exponentially in this type of gas field. Comparison with production testing results shows that the results are more conservative and can be cross-referenced with the conventional "single-point method" evaluation results to determine gas well production capacity.

[0144] Table 2 Comparison of Production Capacity Evaluation Results of the Second and Third Gas Fields

[0145]

[0146] Based on the same inventive concept, embodiments of this specification also provide a device for evaluating the production capacity of gas wells in carbonate gas fields, such as... Figure 4 As shown, the device includes:

[0147] The historical data processing module 401 is used to acquire historical well logging data of gas wells in various types of carbonate gas fields, and to acquire well logging formation coefficient and well logging energy storage coefficient based on the historical well logging data.

[0148] The coefficient relationship of the binomial productivity equation is obtained based on the aforementioned well logging history data;

[0149] The historical data processing module 401 is used to acquire historical well logging data of gas wells in various types of carbonate gas fields, and to acquire well logging formation coefficient and well logging energy storage coefficient based on the historical well logging data.

[0150] The coefficients of the binomial productivity equation were obtained based on the historical well logging data.

[0151] The relationship diagram drawing module 402 is used to draw a first relationship diagram between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship diagram between the well test logging energy storage coefficient and the well test logging formation coefficient;

[0152] Gas field well classification module 403 is used to classify the carbonate gas field wells according to the distinguishing features of the first relationship map and the second relationship map;

[0153] The coefficient relationship fitting module 404 is used to fit the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation according to the classification results.

[0154] The gas well static pressure test module 405 is used to acquire logging data of a gas well to be evaluated for production capacity, including logging formation coefficient and logging storage coefficient, and to conduct a pre-production static pressure test on the gas well to be evaluated for production capacity to obtain its original formation pressure.

[0155] The production capacity coefficient acquisition module 406 is used to determine the type of the gas well to be evaluated based on the logging data, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated to determine the binomial production capacity equation coefficient of the gas well to be evaluated.

[0156] The gas well productivity evaluation module 407 is used to substitute the coefficients of the binomial productivity equation of the gas well to be evaluated and its original formation pressure into the gas field gas well productivity calculation formula to generate the productivity evaluation of the gas well to be evaluated.

[0157] like Figure 5 The diagram shown is a structural schematic of a computer device according to an embodiment of this specification. The methods described in this specification can be applied to the computer device of this embodiment.

[0158] Specifically, such as Figure 5As shown, computer device 502 may include one or more processing devices 504, such as one or more central processing units (CPUs), each of which may implement one or more hardware threads. Computer device 502 may also include any storage resource 506 for storing information of any kind, such as code, settings, data, etc. Non-limitingly, for example, storage resource 506 may include any combination of one or more of the following: any type of RAM, any type of ROM, flash memory devices, hard disks, optical disks, etc. More generally, any storage resource can use any technology to store information.

[0159] Furthermore, any storage resource can provide volatile or non-volatile retention of information.

[0160] Furthermore, any storage resource can represent a fixed or removable component of the computer device 502. In one case, when the processing device 504 executes associated instructions stored in any storage resource or combination of storage resources, the computer device 502 can perform any operation of the associated instructions. The computer device 502 also includes one or more drive systems 508 for interacting with any storage resource, such as a hard disk drive system, an optical disk drive system, etc.

[0161] Computer device 502 may also include an input / output module 510 (I / O) for receiving various inputs (via input device 512) and providing various outputs (via output device 514). A specific output mechanism may include a presentation device 516 and an associated graphical user interface (GUI) 518. In other embodiments, the input / output module 510 (I / O), input device 512, and output device 514 may be omitted, and the device may function solely as a computer device within a network. Computer device 502 may also include one or more network interfaces 520 for exchanging data with other devices via one or more communication links 522. One or more communication buses 524 couple the components described above together.

[0162] Communication link 522 can be implemented in any way, such as via a local area network, a wide area network (e.g., the Internet), a point-to-point connection, or any combination thereof. Communication link 522 may include any combination of hardwired links, wireless links, routers, gateway functions, name servers, etc., governed by any protocol or combination of protocols.

[0163] This specification also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method.

[0164] This specification also provides computer-readable instructions, wherein when a processor executes the instructions, the program therein causes the processor to perform the above-described method.

[0165] It should be understood that in the various embodiments of this specification, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0166] It should also be understood that, in the embodiments of this specification, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, in the embodiments of this specification, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0167] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of the embodiments in this specification.

[0168] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0169] In the embodiments provided in this specification, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, or they may be electrical, mechanical, or other forms of connection.

[0170] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described in this specification, depending on actual needs.

[0171] Furthermore, the functional units in the various embodiments of this specification can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0172] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solutions of the embodiments of this specification, in essence, or the parts that contribute to the prior art, or all or part of the technical solutions, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this specification. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0173] This specification describes the principles and implementation methods of the embodiments using specific examples. The above descriptions of the embodiments are only for the purpose of helping to understand the methods and core ideas of the embodiments in this specification. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the embodiments in this specification. Therefore, the content of this specification should not be construed as a limitation on the embodiments in this specification.

Claims

1. A method for evaluating the productivity of gas wells in carbonate gas fields, characterized in that, The method includes: Obtain historical logging data of gas wells in various types of carbonate gas fields, and obtain the formation coefficient and energy storage coefficient of the well logging based on the historical logging data; The coefficients of the binomial productivity equation were obtained based on the historical well logging data. Draw a first relationship chart between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship chart between the well test logging storage coefficient and the well test logging formation coefficient; Based on the distinguishing features of the first relationship map and the second relationship map, the gas wells in the carbonate gas field are classified. Based on the classification results, the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation are fitted respectively; Obtain logging data for a gas well awaiting production capacity evaluation, including logging formation coefficient and logging storage coefficient, and conduct a pre-production static pressure test on the gas well awaiting production capacity evaluation to obtain its original formation pressure; Based on the logging data of the gas well to be evaluated for production capacity, determine its corresponding type, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated for production capacity to determine the binomial production capacity equation coefficient of the gas well to be evaluated for production capacity. Substitute the coefficients of the binomial production capacity equation of the gas well to be evaluated and its original formation pressure into the gas field's gas well production capacity calculation formula to generate the production capacity evaluation of the gas well to be evaluated.

2. The method for evaluating the production capacity of gas wells in carbonate gas fields according to claim 1, characterized in that, The coefficients of the binomial productivity equation obtained from the aforementioned well testing and logging history data further include... The coefficients of the binomial capacity equation are as follows: In the formula, A represents the Darcy seepage term coefficient for stable gas wells; μ g Z represents gas viscosity; T represents temperature; r represents well radius; subscript w represents wellbore; subscript e represents venting zone; S represents skin factor; B represents stable non-Darcy flow term coefficient of gas well; K represents gas reservoir permeability; h is reservoir thickness; D represents non-Darcy flow coefficient.

3. The method for evaluating the productivity of gas wells in carbonate gas fields according to claim 2, characterized in that, The first graph plotting the relationship between the well test logging formation coefficients and the binomial productivity equation coefficients further includes... The first relationship diagram is represented as follows: A=a(Kh) b , B=a'(Kh) b ', In the formula, A represents the stable Darcy seepage term coefficient of the gas well; B represents the stable non-Darcy seepage term coefficient of the gas well; Kh is the formation coefficient of the gas well logging; and a, a', b, and b' are the fitted empirical numbers.

4. The method for evaluating the productivity of gas wells in carbonate gas fields according to claim 1, characterized in that, The second relationship chart between the well test logging storage coefficient and the well test logging formation coefficient further includes... The second relationship diagram is represented as follows: Kh=c(φh) 2 +d(φh), In the formula, c and d are empirical numbers for fitting; φh is the well logging energy storage coefficient.

5. The method for evaluating the production capacity of gas wells in carbonate gas fields according to claim 4, characterized in that, The pre-production static pressure test of the gas well to be evaluated for production capacity further includes, The stopping point depth and pressure data in the wellbore of the gas well to be evaluated for production capacity are recorded by a pressure gauge, and the stopping point depth is converted into the stopping point vertical depth. Based on the pressure gradient of the last two stopping points of the wellbore fitted with the vertical depth of the stopping point, the pressure in the middle of the producing layer of the gas well to be evaluated for production capacity is calculated based on the pressure gradient and recorded as the original formation pressure.

6. The method for evaluating the production capacity of gas wells in carbonate gas fields according to claim 5, characterized in that, The pressure gradient at the last two stopping points, fitted based on the vertical depth of the stopping point, further includes... The gas wellbore under production capacity evaluation has n stopping points. The vertical depth of the (n-1)th stopping point is denoted as H1, the vertical depth of the nth stopping point is denoted as H2, the pressure of the (n-1)th stopping point is denoted as p1, and the pressure of the nth stopping point is denoted as p2. The pressure gradient is calculated using the following formula: In the formula, Δp is the pressure gradient; p1 is the pressure gradient at the (n-1)th stop point; p2 is the pressure at the nth stop point; H1 is the vertical depth at the (n-1)th stop point; and H2 is the vertical depth at the nth stop point.

7. The method for evaluating the productivity of gas wells in carbonate gas fields according to claim 6, characterized in that, The pressure in the middle of the producing layer of the gas well to be evaluated for production capacity is calculated based on the pressure gradient and recorded as the original formation pressure. Further, it includes... The formula for calculating the pressure in the middle of the gas well producing zone is as follows: p = p² + (H - H²)Δp In the formula, p is the pressure in the middle of the gas well producing layer; p2 is the pressure at the nth stopping point; H is the vertical depth in the middle of the gas well producing layer; H2 is the vertical depth at the nth stopping point; and Δp is the pressure gradient.

8. The method for evaluating the productivity of gas wells in carbonate gas fields according to claim 7, characterized in that, Substituting the well logging formation coefficients into the first relational expression corresponding to the type of gas well to be evaluated for production capacity further includes... If the logging data of the gas well to be evaluated for production capacity is missing the logging formation coefficient, then according to the classification results, the second relationship between the logging storage coefficient and the logging formation coefficient of different types of well tests will be fitted respectively. Substituting the well logging energy storage coefficient of the gas well to be evaluated into the second relationship, the well logging formation coefficient of the gas well to be evaluated is obtained.

9. The method for evaluating the productivity of gas wells in carbonate gas fields according to claim 8, characterized in that, The formula for calculating the gas well productivity of the gas field is as follows: In the formula, q AOF This indicates a stable, absolutely unobstructed flow rate at the gas well; P R This represents the original formation pressure.

10. A device for evaluating the productivity of gas wells in carbonate gas fields, characterized in that, The device includes: The historical data processing module is used to acquire historical well logging data of gas wells in various types of carbonate gas fields, and to obtain well logging formation coefficient and well logging energy storage coefficient based on the historical well logging data. The coefficients of the binomial productivity equation were obtained based on the historical well logging data. The relationship diagram drawing module is used to draw a first relationship diagram between the well test logging formation coefficient and the binomial productivity equation coefficient, and a second relationship diagram between the well test logging energy storage coefficient and the well test logging formation coefficient; The gas field and gas well classification module is used to classify the gas wells of the carbonate gas field according to the distinguishing features of the first relationship map and the second relationship map; The coefficient relationship fitting module is used to fit the first relationship between the formation coefficients of different types of well test logging and the coefficients of the binomial productivity equation based on the classification results. The gas well static pressure test module is used to acquire logging data of a gas well to be evaluated for production capacity, including logging formation coefficient and logging storage coefficient, and to conduct a pre-production static pressure test on the gas well to be evaluated for production capacity to obtain its original formation pressure. The production capacity coefficient acquisition module is used to determine the type of the gas well to be evaluated based on the logging data, and substitute the logging formation coefficient into the first relational expression corresponding to the type of the gas well to be evaluated to determine the binomial production capacity equation coefficient of the gas well to be evaluated. The gas well productivity evaluation module is used to substitute the coefficients of the binomial productivity equation of the gas well to be evaluated and its original formation pressure into the gas field gas well productivity calculation formula to generate the productivity evaluation of the gas well to be evaluated.

11. A computer device comprising a memory, a processor, and a computer program stored in the memory, characterized in that, When the processor executes the computer program, it implements the method according to any one of claims 1 to 9.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the method of any one of claims 1 to 9.

13. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by a processor, implements the method of any one of claims 1 to 9.

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