Method and system for predicting favorable targets in a superimposed gas reservoir based on source-reservoir configuration relationship

Abstract

The present application belongs to the technical field of oil and gas exploration, and relates to a method and system for predicting favorable targets of superimposed gas reservoirs based on source-reservoir configuration relationship. The present application obtains a reservoir thickness contour map and an effective reservoir thickness contour map; obtains a source-reservoir configuration coefficient contour map according to the excess pressure of a hydrocarbon source rock, the median pressure of a reservoir, and the vertical distance between the hydrocarbon source rock and the reservoir; and obtains a storage energy coefficient contour map using the effective thickness of the reservoir, the gas saturation, and the porosity of the reservoir. The favorable area of the dense reservoir under the condition of low-permeability-dense superimposed gas reservoirs is predicted according to the reservoir thickness contour map, the effective reservoir thickness contour map, the source-reservoir configuration coefficient contour map, and the storage energy coefficient contour map. The present application can comprehensively evaluate the formation conditions and the reservoir capacity of superimposed gas reservoirs in different regions by integrating the information of the above four contour maps, and can accurately screen the favorable area of the dense reservoir under the condition of low-permeability-dense superimposed gas reservoirs.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas exploration technology, and relates to a method and system for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration. Background Technology

[0002] As gas field development progresses, it faces two main challenges: first, all low-permeability, high-efficiency reserves have been utilized, and the field is now in a declining phase, making it impossible to guarantee sustained and stable production; second, the tight gas reservoirs suffer from poor reservoir quality, small sandstone bodies, and poor continuity, resulting in low average well production and significant challenges to profitable development. Therefore, it is urgent to conduct research on methods for selecting favorable areas in tight sandstone successor strata within the context of low-permeability gas reservoir development, establish methods suitable for screening favorable areas in low-permeability-tight composite gas reservoirs, optimize the development of advantageous areas in tight gas reservoirs, explore new areas for profitable development, and promote sustained, efficient, and stable gas field production.

[0003] Currently, evaluation methods and standards for tight sandstone gas reservoirs and favorable areas have been established both domestically and internationally. At the same time, different scholars have also published relevant articles on the selection of favorable areas, mainly through comprehensive analysis of the target stratigraphic structure, sedimentary facies, reservoir characteristics and hydrocarbon accumulation mechanism, to clarify the planar distribution characteristics of favorable areas in tight sandstone.

[0004] The existing technologies mentioned above are mostly focused on the classification and evaluation of single-target tight sandstone reservoirs. The relevant research and methods do not focus on the overall analysis and systematic study of low-permeability-tight superimposed gas reservoirs. At the same time, they do not consider relevant parameters such as source-reservoir configuration as the basis for screening favorable areas, which leads to inaccurate screening of favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions.

[0005] In summary, existing technologies have limitations in accurately identifying favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a method and system for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, in order to solve the technical problem that the existing technology is not accurate enough in screening favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions. By comprehensively considering factors such as source-reservoir configuration relationships, this invention can achieve accurate screening of favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions.

[0007] To achieve the above objectives, the present invention employs the following technical solution: Thirdly, the present invention provides a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, comprising the following steps: Obtain the reservoir thickness contour map and the effective reservoir thickness contour map; The contour map of source-reservoir configuration coefficients was obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. A contour map of the energy storage coefficient was obtained using the effective reservoir thickness, gas saturation, and reservoir porosity. Predict favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions based on isopleth maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient.

[0008] Furthermore, the acquisition of the reservoir thickness contour map and the effective reservoir thickness contour map is specifically as follows: Based on the sedimentary facies distribution characteristics of the superimposed gas reservoir, contour maps of reservoir thickness and effective reservoir thickness were obtained.

[0009] Furthermore, the contour map of the source-reservoir configuration coefficient obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir is as follows: The source-reservoir configuration coefficients for each well are obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. A contour map of the source-reservoir configuration coefficients is then obtained based on these coefficients.

[0010] Furthermore, the source-reservoir configuration coefficient for each single well is obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The specific formula for obtaining the coefficient is as follows:

[0011] in, This refers to the source-storage configuration coefficient. Excess pressure in source rocks; denoted as median reservoir pressure; S is the distance between the source rock and the reservoir; A is a constant.

[0012] Furthermore, the method for obtaining the excess pressure of the source rock is as follows: The abnormal pressure of formation fluids is obtained based on the formation water static pressure gradient, the equivalent depth of the source rock section, the average pressure gradient of the overlying rocks, the burial depth of the source rock section at the abnormal compaction point, and the equivalent depth of the source rock section. The hydrostatic pressure of the formation is obtained by the formation water hydrostatic gradient and the burial depth of the source rock strata at the abnormal compaction point. Excess pressure of source rocks is obtained from abnormal pressure of formation fluids and hydrostatic pressure of formation.

[0013] Furthermore, the formula for obtaining the excess pressure of the source rock based on the abnormal pressure of the formation fluid and the hydrostatic pressure of the formation is as follows:

[0014] in, Excess pressure in source rocks; This refers to abnormal pressure of formation fluids; This represents the hydrostatic pressure of the formation.

[0015] Furthermore, the method of obtaining the energy storage coefficient contour map using the effective reservoir thickness, gas saturation, and reservoir porosity is as follows: The single-layer energy storage coefficient of each well is obtained by utilizing the effective reservoir thickness, gas saturation, and reservoir porosity. Based on the single-layer energy storage coefficient of each well, a contour map of the energy storage coefficient is obtained.

[0016] Secondly, the present invention provides a system for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, comprising: The plan view acquisition module is used to acquire the reservoir thickness contour plan view and the effective reservoir thickness contour plan view; The source-reservoir configuration coefficient contour map acquisition module is used to obtain the source-reservoir configuration coefficient contour map based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The energy storage coefficient contour map acquisition module is used to obtain the energy storage coefficient contour map using the effective thickness of the reservoir, gas saturation and reservoir porosity. The module for predicting favorable areas of superimposed gas reservoirs is used to predict favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions based on contour maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient.

[0017] Thirdly, the present invention provides an electronic device, comprising: a processor; a memory for storing computer program instructions; and steps for implementing a method for predicting favorable targets of superimposed gas reservoirs based on source-reservoir configuration relationships when executing the computer program.

[0018] Fourthly, the present invention provides a storage medium storing computer program instructions, which are loaded and executed by a processor, wherein the processor executes a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention obtains isopleth maps of reservoir thickness and effective reservoir thickness; it also obtains isopleth maps of source-reservoir configuration coefficients based on excess pressure of the source rock, median pressure of the reservoir, and vertical distance between the source rock and the reservoir; and it obtains isopleth maps of energy storage coefficients using effective reservoir thickness, gas saturation, and reservoir porosity. The comprehensive analysis of these isopleth maps facilitates the accurate screening of favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions. Based on these isopleth maps, favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions can be predicted. By integrating the information from these four isopleth maps, the formation conditions and storage capacity of composite gas reservoirs in different regions can be comprehensively evaluated. Comparative analysis can identify areas with large reservoir thickness, high effective reservoir thickness, good source-reservoir configuration, and high energy storage coefficient as favorable target areas for superimposed gas reservoirs.

[0020] 2. This system includes: a planar map acquisition module, a source-reservoir configuration coefficient contour map acquisition module, a storage coefficient contour map acquisition module, and a favorable area prediction module for superimposed gas reservoirs. The planar map acquisition module is used to acquire reservoir thickness contour maps and effective reservoir thickness contour maps; the source-reservoir configuration coefficient contour map acquisition module is used to acquire source-reservoir configuration coefficient contour maps based on excess pressure of the source rock, median pressure of the reservoir, and vertical distance between the source rock and the reservoir; the storage coefficient contour map acquisition module is used to acquire storage coefficient contour maps using effective reservoir thickness, gas saturation, and reservoir porosity; the favorable area prediction module for superimposed gas reservoirs is used to predict favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions based on the reservoir thickness contour maps, effective reservoir thickness contour maps, source-reservoir configuration coefficient contour maps, and storage coefficient contour maps. The various modules work together to enable the precise screening of favorable areas in tight reservoirs under low-permeability-tight composite gas reservoir conditions.

[0021] 3. The electronic device and storage medium of the present invention can also achieve accurate screening of favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the equilibrium depth method of the present invention; Figure 2 This is an AC curve of acoustic transit time at different depths in a well according to an embodiment of the present invention; Figure 3 This is a diagram of excess pressure in a coal seam according to an embodiment of the present invention. Figure 4 This is a calculation diagram of the median pressure of reservoir 8 in an embodiment of the present invention; Figure 5 This is a calculation diagram of the median pressure of the Shan 2 reservoir according to an embodiment of the present invention; Figure 6 This is a bar chart showing the secondary production layer encounters of the Hanshan 2 gas-bearing well according to an embodiment of the present invention; Figure 7 This is a diagram illustrating the reservoir formation model of the low-permeability-tight superimposed sandstone gas reservoir in the Shan 2 and He 8 sections according to an embodiment of the present invention. Figure 8 This is a flowchart of the method of the present invention; Figure 9 This is a system module diagram of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0024] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention 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 the embodiments of the invention 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 a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises 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 apparatus.

[0025] The present invention will now be described in further detail with reference to the accompanying drawings: See Figure 8 This invention discloses a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, comprising the following steps: S1. Obtain the reservoir thickness contour map and the effective reservoir thickness contour map. Reservoir thickness is one of the important parameters for evaluating oil and gas reservoir reserves. By obtaining the reservoir thickness contour map, we can intuitively understand the spatial distribution characteristics of the reservoir, which is beneficial for the accurate screening of favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions.

[0026] S2. Based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir, a contour map of the source-reservoir configuration coefficient is obtained. The contour map of the source-reservoir configuration coefficient can show the advantages and disadvantages of the configuration relationship between the source rock and the reservoir in different regions, which helps to identify favorable areas for oil and gas migration and accumulation.

[0027] S3 utilizes reservoir effective thickness, gas saturation, and reservoir porosity to obtain a contour map of the storage coefficient. This contour map comprehensively considers factors such as effective reservoir thickness, gas saturation, and porosity. A greater effective thickness, higher gas saturation, and better porosity result in a higher storage coefficient and a stronger capacity for storing oil and gas. The contour map of the storage coefficient can reflect the differences in the storage capacity of the reservoir in different regions, providing an important basis for predicting favorable oil and gas reservoir areas.

[0028] S4. Based on the isopleth maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient, favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions are predicted. By integrating the information from these four isopleth maps, the formation conditions and storage capacity of composite gas reservoirs in different regions can be comprehensively assessed. Through comparative analysis, areas with large reservoir thickness, high effective reservoir thickness, good source-reservoir configuration, and high energy storage coefficient can be identified as favorable target areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions.

[0029] Example 1: See Figure 8 This embodiment discloses a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, including the following steps: S1, Obtain the reservoir thickness contour map and the effective reservoir thickness contour map, as detailed below: Based on the sedimentary facies distribution characteristics of the superimposed gas reservoir, contour maps of reservoir thickness and effective reservoir thickness were obtained.

[0030] S2, based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir, a contour map of the source-reservoir configuration coefficient is obtained, as follows: The source-reservoir configuration coefficients for each well are obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. A contour map of the source-reservoir configuration coefficients is then obtained based on these coefficients.

[0031] Preferably, the source-reservoir configuration coefficient for each single well is obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The specific formula for obtaining the coefficient is as follows:

[0032] in, This refers to the source-storage configuration coefficient. Excess pressure in source rocks; denoted as median reservoir pressure; S is the distance between the source rock and the reservoir; A is a constant.

[0033] Preferably, the method for obtaining the excess pressure of the source rock is as follows: The abnormal pressure of formation fluids is obtained based on the formation water static pressure gradient, the equivalent depth of the source rock section, the average pressure gradient of the overlying rocks, the burial depth of the source rock section at the abnormal compaction point, and the equivalent depth of the source rock section. The hydrostatic pressure of the formation is obtained by the formation water hydrostatic gradient and the burial depth of the source rock strata at the abnormal compaction point. The excess pressure of the source rock is obtained based on the abnormal pressure of formation fluids and the hydrostatic pressure of the formation, as follows:

[0034] in, Excess pressure in source rocks; This refers to abnormal pressure of formation fluids; This represents the hydrostatic pressure of the formation.

[0035] S3. A contour map of the energy storage coefficient was obtained using the effective reservoir thickness, gas saturation, and reservoir porosity, as shown below: The single-layer energy storage coefficient of each well is obtained by utilizing the effective reservoir thickness, gas saturation and reservoir porosity, and the energy storage coefficient contour map is obtained based on the single-layer energy storage coefficient of each well. Preferably, the single-layer energy storage coefficient of each well is obtained by utilizing the effective reservoir thickness, gas saturation, and reservoir porosity, and the specific formula is as follows:

[0036] in, Energy storage coefficient; The effective thickness of the reservoir; The average porosity of the reservoir; This represents the gas saturation level of the reservoir.

[0037] S4. Based on the reservoir thickness contour map, effective reservoir thickness contour map, source-reservoir configuration coefficient contour map, and energy storage coefficient contour map, predict the favorable area of ​​tight reservoir under low-permeability-tight superimposed gas reservoir conditions.

[0038] Example 2: See Figure 8 This embodiment discloses a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, including the following steps: This invention fully considers the differences in characteristics between low-permeability and tight superimposed gas reservoirs, and uses multiple parameters such as the source-reservoir configuration coefficient of low-permeability and tight superimposed gas reservoirs as the criteria for selecting favorable areas. It is the first to clearly define a comprehensive classification standard suitable for favorable areas of low-permeability and tight superimposed gas reservoirs, thus overcoming the shortcomings of existing methods in the classification of favorable areas for superimposed gas reservoirs. Specifically: Step 1: Collect basic data from completed wells in the study area, including reservoir-related parameters such as the thickness of low-permeability and tight reservoirs, effective reservoir thickness, porosity, permeability, and gas saturation; source-reservoir configuration data such as the distance between the source rock and the low-permeability and tight reservoirs; various logging curves such as sonic transit time and resistivity, as well as logging vertical correction results; production dynamic data such as gas testing data; and experimental data such as high-pressure mercury intrusion. Step 2: Based on the study of sedimentary facies such as single-well facies and interconnected-well facies, clarify the distribution characteristics of sedimentary facies, and on the basis of the sedimentary facies study, draw contour maps of low-permeability tight reservoir thickness and effective reservoir thickness to clarify the spatial distribution law of reservoir; Step 3: Calculate the excess pressure of the source rock, i.e., the hydrocarbon accumulation driving force, using the equilibrium depth method; Step 4: Use high-pressure mercury intrusion experiments to obtain median pressure data for tight and low-permeability reservoirs with a mercury intrusion rate of 50%. Establish the correlation between median pressure and reservoir porosity and permeability. Use median pressure to establish regression formulas for the permeability of low-permeability reservoir (Shan 2 section) and porosity of tight reservoir (He 8 section). Calculate the median pressure data for low-permeability and tight reservoirs in single wells without high-pressure mercury intrusion experiment data.

[0039]

[0040]

[0041] In the formula: The median pressure of the Shan 2 reservoir is The value represents the median pressure of the reservoir in section 8, in MPa. The average permeability of the Shan 2 section reservoir is expressed in mD. The average porosity of the reservoir in section 8 of the box is given.

[0042] Step 5: Calculate the excess pressure of the source rock and the median pressure of the reservoir. Use the vertical correction results of the well logging to read the vertical distance between the source rock and the low-permeability reservoir and the tight reservoir. Calculate the source-reservoir configuration coefficient using the ratio of the pressure difference to the vertical distance. Draw a contour map of the source-reservoir configuration coefficient based on the data points from a single well.

[0043] In the formula: This refers to the source-storage configuration coefficient. This represents the excess pressure of the source rock, expressed in MPa. ρ is the median pressure in the reservoir, in MPa; S is the distance between the source rock and the reservoir, in meters; A is a constant, 100.

[0044] Step 6: Calculate the energy storage coefficient of a single layer using the effective reservoir thickness, gas saturation, and reservoir porosity, and draw a contour map of the energy storage coefficient based on the data points from the single well.

[0045]

[0046] In the formula: Energy storage coefficient; The effective thickness of the reservoir is expressed in meters (m). The average porosity of the reservoir; This represents the gas saturation level of the reservoir.

[0047] Step 7: By comprehensively utilizing contour maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient, the formation law of low-permeability-tight superimposed gas reservoirs is clarified. Furthermore, by comprehensively utilizing various parameters, a standard for dividing favorable areas of superimposed gas reservoirs is established, and the distribution range of favorable areas is clarified.

[0048] In summary, the effects of the present invention are as follows: By applying this invention to the development of a low-permeability tight gas reservoir in a gas field, and through comprehensive geological analysis, based on the technological process and research results, a favorable area of ​​566.8 km² was selected. 2 With a geological reserve of 49.26 billion cubic meters, the proportion of Class I+II wells has continued to rise. On the west side, 34 horizontal wells of the tight gas reservoir section 8 have been drilled, with an average average section length of 1333m. The reservoir drilling rate is 78.7%, and the unobstructed gas flow rate during testing is 477,000 cubic meters per day, generating significant development benefits and achieving good overall application results.

[0049] This invention enables the screening of favorable areas for tight gas reservoirs in the context of low-permeability gas reservoirs, laying the foundation for continuous and stable production. It has universal reference value and applicability for similar superimposed gas reservoirs, and the market size is huge.

[0050] Example 3: See Figure 8 This embodiment discloses a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, including the following steps: Step 1: Calculate the excess pressure of the source rock using the equilibrium depth method. Taking well A as an example, the depth of the source rock section is 2845m, and its equivalent depth is 1010m. The calculated excess pressure is 23.3MPa.

[0051]

[0052]

[0053]

[0054] In the formula: This represents the abnormal pressure of formation fluids, expressed in MPa. This represents the hydrostatic pressure of the formation, expressed in MPa. This represents the excess pressure of the source rock, expressed in MPa. This represents the formation water hydrostatic gradient, expressed in MPa / m, typically 1.04 × 10⁻⁶. - 2 MPa / m; This represents the average pressure gradient of the overlying strata rocks, expressed in MPa / m, typically 2.31 × 10⁻⁶. -2 MPa / m; The depth of the source rock stratum at the point of abnormal compaction is expressed in meters. This represents the equivalent depth of the source rock strata, in meters (m). See also... Figure 1 This is a schematic diagram of the equilibrium depth method; Figure 2 The AC curves of acoustic transit time at different depths in a well are shown. By using the abnormal pressure depth to represent the normal pressure depth, the excess pressure of the coal seam can be calculated. (See [reference]). Figure 3 .

[0055] Step 2: Calculate the median pressure of the two gas reservoirs (Shan 2 section and He 8 section) using regression formulas obtained from high-pressure mercury intrusion data and reservoir properties. Taking well A as an example, the permeability of the low-permeability reservoir (Shan 2 section) is 0.79 mD, and the porosity of He 8 is 8.4%. The median pressure of Shan 2 is calculated to be 4.9 MPa, and the median pressure of He 8 is 9.6 MPa.

[0056]

[0057]

[0058] In the formula, The median pressure of the low-permeability reservoir (Shan 2 section) is expressed in MPa. The median pressure of the tight reservoir (Section 8) is expressed in MPa.

[0059] See Figure 4 The diagram shows the calculated median pressure of reservoir 8. Figure 5 This is a calculation diagram of the median pressure of the Shan 2 reservoir in an embodiment of the present invention. By establishing the regression relationship between the median pressure obtained from the high-pressure mercury intrusion test and the reservoir properties, the median pressure of the He 8 section has a good correlation with the reservoir porosity, and the median pressure of the Shan 2 section has a good correlation with the reservoir permeability. The median pressure of different reservoirs is calculated using the regression formula.

[0060] Step 3: Calculate the source-reservoir configuration coefficient using the excess pressure, median pressure, and vertical distance between the source rock and the reservoir. Taking well A as an example, the source rock is 66m away from the Shan 2 reservoir and 174m away from the He 8 reservoir. The source-reservoir configuration coefficient for Shan 2 is 27.9, and the source-reservoir configuration coefficient for He 8 is 7.9.

[0061]

[0062] in, For the source-reservoir configuration coefficient of the Shan 2 section reservoir; The source-reservoir configuration coefficient for the 8th section of the reservoir; Step 4: Calculate the energy storage coefficients of different types of reservoirs using the average reservoir porosity, effective reservoir thickness, and gas saturation. Taking well A as an example, the low-permeability reservoir (Shan 2 section) has an average porosity of 4.9%, an average gas saturation of 69.3%, and an effective reservoir thickness of 16.4m. The tight reservoir (He 8 section) has an average porosity of 8.4%, an average gas saturation of 49.8%, and an effective reservoir thickness of 3.8m. The calculated reservoir coefficients for Shan 2 and He 8 are 0.51 and 0.16 respectively.

[0063]

[0064] In the formula: Energy storage coefficient; The energy storage coefficient of box segment 8; The effective thickness of the reservoir is expressed in meters (m). The average porosity of the reservoir; This represents the gas saturation level of the reservoir.

[0065] Step 5: By comprehensively utilizing relevant parameters such as reservoir thickness, effective reservoir thickness, reservoir porosity, reservoir permeability, reservoir gas saturation, reservoir energy storage coefficient, and source-reservoir configuration coefficient, a selection criterion for favorable areas of Box 8 tight reservoir under the background of low-permeability reservoir development is established, as shown in Table 1.

[0066] Table 1. Criteria for Delineating Favorable Zones of Low-Permeability-Tight Composite Gas Reservoirs:

[0067] Step Six: By comprehensively utilizing contour maps of reservoir thickness and effective reservoir thickness, source-reservoir configuration coefficients, and energy storage coefficients, the dislocation-based accumulation pattern of the Shan 2 low-permeability-He 8 tight gas reservoir is clarified, and the distribution range of favorable areas in the He 8 tight reservoir is comprehensively predicted. (See also...) Figure 6 This is a bar chart showing the secondary production layer encounters of the Hanshan 2 gas-bearing well according to an embodiment of the present invention; Figure 7 This is a schematic diagram of the reservoir formation model of the low-permeability-tight superimposed sandstone gas reservoir in the Shan 2 and He 8 sections according to an embodiment of the present invention.

[0068] In summary, this invention fully considers the differences in the characteristics of low-permeability and tight superimposed reservoirs, conducts overall analysis and systematic research on low-permeability and tight superimposed gas reservoirs, and uses multiple parameters such as the source-reservoir configuration relationship of low-permeability and tight superimposed gas reservoirs as the selection criteria for favorable areas. For the first time, it clarifies the comprehensive classification criteria for favorable areas suitable for this region, making up for the shortcomings of existing methods in the classification of favorable areas. This technology has reference value and application prospects for the study of similar gas reservoirs.

[0069] Based on the above method, this invention also discloses a system for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships. See [link to relevant documentation]. Figure 9 ,include: The plan view acquisition module is used to acquire the reservoir thickness contour plan view and the effective reservoir thickness contour plan view; The source-reservoir configuration coefficient contour map acquisition module is used to obtain the source-reservoir configuration coefficient contour map based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The energy storage coefficient contour map acquisition module is used to obtain the energy storage coefficient contour map using the effective thickness of the reservoir, gas saturation and reservoir porosity. The module for predicting favorable areas of superimposed gas reservoirs is used to predict favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions based on contour maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient.

[0070] The various modules of the system of this invention work together to achieve precise screening of favorable areas in low-permeability-tight composite gas reservoirs.

[0071] An electronic device includes: a processor; a memory for storing computer program instructions; and steps for implementing a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships when executing the computer program.

[0072] A storage medium storing computer program instructions, which are loaded and executed by a processor, wherein the processor performs a method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships.

[0073] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0074] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0075] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0076] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0077] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, characterized in that, Includes the following steps: Obtain the reservoir thickness contour map and the effective reservoir thickness contour map; The contour map of source-reservoir configuration coefficients was obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. A contour map of the energy storage coefficient was obtained using the effective reservoir thickness, gas saturation, and reservoir porosity. Predict favorable areas for tight reservoirs under low-permeability-tight composite gas reservoir conditions based on isopleth maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient.

2. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 1, characterized in that, The specific steps for obtaining the reservoir thickness contour map and the effective reservoir thickness contour map are as follows: Based on the sedimentary facies distribution characteristics of the superimposed gas reservoir, contour maps of reservoir thickness and effective reservoir thickness were obtained.

3. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 1, characterized in that, The contour map of the source-reservoir configuration coefficient is obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir, as detailed below: The source-reservoir configuration coefficients for each well are obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. A contour map of the source-reservoir configuration coefficients is then obtained based on these coefficients.

4. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 3, characterized in that, The source-reservoir configuration coefficient for each single well is obtained based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The specific formula for obtaining the coefficient is as follows: in, This refers to the source-storage configuration coefficient. Excess pressure in source rocks; denoted as median reservoir pressure; S is the distance between the source rock and the reservoir; A is a constant.

5. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 1 or 3, characterized in that, The method for obtaining the excess pressure of the source rock is as follows: The abnormal pressure of formation fluids is obtained based on the formation water static pressure gradient, the equivalent depth of the source rock section, the average pressure gradient of the overlying rocks, the burial depth of the source rock section at the abnormal compaction point, and the equivalent depth of the source rock section. The hydrostatic pressure of the formation is obtained by the formation water hydrostatic pressure gradient and the burial depth of the source rock strata at the abnormal compaction point. Excess pressure of source rocks is obtained from abnormal pressure of formation fluids and hydrostatic pressure of formation.

6. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 5, characterized in that, The specific formula for obtaining the excess pressure of the source rock based on the abnormal pressure of formation fluids and the hydrostatic pressure of the formation is as follows: in, Excess pressure in source rocks; This refers to abnormal pressure of formation fluids; This represents the hydrostatic pressure of the formation.

7. The method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships according to claim 1, characterized in that, The method for obtaining the energy storage coefficient contour map using the effective reservoir thickness, gas saturation, and reservoir porosity is as follows: The single-layer energy storage coefficient of each well is obtained by utilizing the effective reservoir thickness, gas saturation, and reservoir porosity. Based on the single-layer energy storage coefficient of each well, a contour map of the energy storage coefficient is obtained.

8. A system for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships, characterized in that, include: The plan view acquisition module is used to acquire the reservoir thickness contour plan view and the effective reservoir thickness contour plan view; The source-reservoir configuration coefficient contour map acquisition module is used to obtain the source-reservoir configuration coefficient contour map based on the excess pressure of the source rock, the median pressure of the reservoir, and the vertical distance between the source rock and the reservoir. The energy storage coefficient contour map acquisition module is used to obtain the energy storage coefficient contour map using the effective thickness of the reservoir, gas saturation and reservoir porosity. The module for predicting favorable areas of superimposed gas reservoirs is used to predict favorable areas of tight reservoirs under low-permeability-tight superimposed gas reservoir conditions based on contour maps of reservoir thickness, effective reservoir thickness, source-reservoir configuration coefficient, and energy storage coefficient.

9. An electronic device, comprising: A processor; a memory, an electronic device for storing computer program instructions; characterized in that, when executing the computer program, it implements the steps of the method for predicting favorable targets of superimposed gas reservoirs based on source-reservoir configuration relationships as described in any one of claims 1-7.

10. A storage medium storing computer program instructions, characterized in that, When the computer program instructions are loaded and run by the processor, the processor executes the method for predicting favorable targets in superimposed gas reservoirs based on source-reservoir configuration relationships as described in any one of claims 1-7.

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