Cover layer closure evaluation method and device, electronic equipment and storage medium
By establishing the correlation between confining pressure and permeability, and using permeability analysis to evaluate the sealing performance of the caprock, the problem of universality in evaluating the sealing performance of the caprock at different deformation stages was solved, thus improving the accuracy and universality of the caprock sealing performance evaluation.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- PETROCHINA CO LTD
- Filing Date
- 2024-10-16
- Publication Date
- 2026-04-17
AI Technical Summary
Existing technologies cannot effectively evaluate the sealing properties of caprocks at different deformation stages, especially the brittle, brittle-ductile, and ductile deformation stages, resulting in insufficient universality of caprock sealing property evaluation methods.
By testing samples of the caprock in the target area, the correlation between confining pressure and permeability is established. The permeability analysis is used to evaluate the caprock's sealing performance. Geodynamic methods are used to construct the correlation between different caprocks, including the exponential relationship P=a*e-bk for the correction coefficient.
It enables universal evaluation of caprocks at any deformation stage, improving the accuracy and universality of caprock sealing evaluation, especially in the sealing evaluation of caprocks in complex fold deformation zones, supporting oil and gas reserve exploration and well location deployment.
Smart Images
Figure CN121877684A_ABST
Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of oil and gas field exploration and development technology, and in particular relates to a method, apparatus, electronic equipment and storage medium for evaluating caprock sealing. Background Technology
[0002] The caprock is one of the key factors for the accumulation and formation of oil and gas in traps. The stability of the caprock is an important factor for the large-scale enrichment of oil and gas and an important condition for the preservation of oil and gas. With the changes in burial depth, diagenesis, physical properties and temperature and pressure environment, the mechanical properties of the caprock will undergo three processes of deformation: brittle, brittle-ductile and ductile. The sealing capacity of the caprock is different at different deformation stages.
[0003] Currently, caprock sealing performance can be evaluated for caprocks in the brittle deformation stage. Specifically, for fault-block lateral sealing caprocks mainly distributed in fault-block traps of interbedded sandstone and mudstone strata, where the caprock strain is primarily brittle deformation, existing technologies determine the sealing performance of fault-block lateral sealing caprocks based on fault displacement, sandstone connectivity, and sand-to-soil ratio.
[0004] Existing technologies can only evaluate the caprock sealing performance during the brittle deformation stage and are not applicable to other deformation stages. Therefore, improving the versatility of caprock sealing evaluation methods so that caprock sealing performance can be evaluated at any deformation stage is a problem that needs to be solved by those skilled in the art. Summary of the Invention
[0005] To address the aforementioned issues, this disclosure provides a method for evaluating the sealing capacity of caprocks, with the aim of improving the versatility of such methods.
[0006] To achieve the above objectives, this disclosure mainly provides the following technical solutions:
[0007] In a first aspect, this disclosure provides a method for evaluating the sealing performance of a cap layer, characterized in that the method includes:
[0008] Samples of the caprock in the target area were tested to obtain the correlation between the confining pressure and permeability of the caprock;
[0009] Based on the confining pressure of the capping layer and the correlation, the permeability of the capping layer is calculated so as to evaluate the sealing performance of the capping layer in the target area based on the permeability.
[0010] Furthermore, samples of the caprock in the target area were tested to obtain the correlation between the confining pressure and permeability of the caprock, including:
[0011] Pressure tests were performed on core samples from the caprock of the target area to obtain confining pressure versus permeability curves.
[0012] The correlation between the confining pressure and permeability of the caprock is calculated based on the confining pressure and permeability curve. The correlation includes a correction coefficient, which is different for different caprocks.
[0013] Furthermore, core samples from the caprock in the target area were subjected to pressure tests to obtain confining pressure versus permeability curves, including:
[0014] Simulating deep burial conditions, the caprock core samples of the target area were pressurized multiple times in a closed environment;
[0015] The permeability of the caprock core samples under different confining pressures was measured to obtain the first data table;
[0016] Generate a curve of confining pressure versus permeability based on the first data table.
[0017] Furthermore, core samples from the caprock in the target area were subjected to pressure tests to obtain confining pressure versus permeability curves, including:
[0018] Obtain core samples of the caprock from multiple natural gas wells in the target area;
[0019] Each core sample was subjected to a closed-loop pressure test, resulting in multiple second data tables.
[0020] Based on the multiple second data tables, a confining pressure versus permeability curve is generated.
[0021] Furthermore, based on the confining pressure of the caprock and the correlation, the permeability of the caprock is calculated, including:
[0022] The confining pressure of the caprock in the target area is determined based on the current tectonic stress and stress field of the target area.
[0023] Substituting the confining pressure into the correlation formula, the permeability of the caprock is calculated. Further, the correlation formula is:
[0024] P = a * e -bk
[0025] Where P is the confining pressure in MPa, K is the permeability in mD, and a and b are correction coefficients.
[0026] Secondly, this disclosure provides a capping layer sealing performance evaluation device, characterized in that the device comprises:
[0027] The testing unit is used to test samples of the caprock in the target area to obtain the correlation between the confining pressure and permeability of the caprock.
[0028] The calculation unit is used to calculate the permeability of the capping layer based on the confining pressure of the capping layer and the correlation relationship, so as to evaluate the sealing performance of the capping layer in the target area based on the permeability.
[0029] Furthermore, the test unit includes:
[0030] The testing module is used to perform pressure tests on core samples of the caprock in the target area to obtain confining pressure versus permeability curves.
[0031] The calculation module is used to calculate the correlation between the confining pressure and permeability of the caprock based on the confining pressure and permeability curve. The correlation includes a correction coefficient, which is different for different caprocks.
[0032] Furthermore, the testing module is specifically used for:
[0033] Simulating deep burial conditions, core samples from the caprock of the target area were subjected to multiple pressurizations in a closed environment;
[0034] The permeability of the caprock core samples under different confining pressures was measured to obtain the first data table;
[0035] Generate a curve of confining pressure versus permeability based on the first data table.
[0036] Furthermore, the testing module is also specifically used for:
[0037] Obtain caprock core samples from multiple natural gas wells in the target area;
[0038] Sealing pressure tests were conducted on caprock core samples from each natural gas well to obtain multiple second data tables;
[0039] Based on the multiple second data tables, a confining pressure versus permeability curve is generated.
[0040] Furthermore, the computing unit includes:
[0041] The confining pressure of the caprock in the target area is determined based on the current tectonic stress and stress field of the target area.
[0042] Substituting the confining pressure into the correlation formula, the permeability of the caprock is calculated. Further, the correlation formula is:
[0043] P = a * e -bk
[0044] Where P is the confining pressure in MPa, K is the permeability in mD, and a and b are correction coefficients.
[0045] On the other hand, this disclosure also provides a storage medium for storing a computer program, wherein the computer program, when running, controls the device where the storage medium is located to execute the capping closure evaluation method described in the first aspect.
[0046] On the other hand, this disclosure also provides an electronic device, the device including at least one processor, and at least one memory and bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute the capping closure evaluation method as described in the first aspect above.
[0047] Compared with the prior art, this disclosure has the following advantages:
[0048] This disclosure presents an embodiment that tests samples of the caprock in a target area, simulating deep burial conditions, to obtain the correlation between confining pressure and permeability of the caprock. Based on the confining pressure of the target area and this correlation, the permeability of the caprock in the target area is obtained. By analyzing the permeability, the caprock sealing performance of the target area is evaluated. This disclosure presents a breakthrough in the difficulty of evaluating caprock sealing performance in complex folded deformation zones of foreland basins. It uses geodynamic methods to construct a correlation between confining pressure and permeability. Since the correlation varies among different caprock formations, this disclosure can be used to evaluate caprock sealing performance regardless of whether the caprock is in a brittle, brittle-ductile, or ductile arbitrary deformation stage, or regardless of the degree of diagenesis. This disclosure presents an embodiment with good versatility, improving the universality of caprock sealing performance evaluation methods compared to existing technologies.
[0049] Other features and advantages of this disclosure will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the disclosure. The objects and other advantages of this disclosure may be realized and obtained by means of the structures pointed out in the description, claims and drawings. Attached Figure Description
[0050] To more clearly illustrate the technical solutions in the embodiments of this disclosure 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 some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0051] Figure 1 A schematic flowchart of a cap layer closure evaluation method according to an embodiment of the present disclosure is shown;
[0052] Figure 2 A flowchart illustrating another cap cover closure evaluation method according to an embodiment of the present disclosure is shown;
[0053] Figure 3 A graph showing confining pressure versus permeability according to an embodiment of this disclosure is shown;
[0054] Figure 4 A schematic diagram of the structure of a capping closure evaluation device according to an embodiment of the present disclosure is shown;
[0055] Figure 5 A schematic diagram of an electronic device structure according to an embodiment of the present disclosure is shown. Detailed Implementation
[0056] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.
[0057] The sealing capacity of caprocks under deep burial conditions in folded deformation zones is affected by the caprock's brittleness, ductility, and diagenesis degree. Existing technologies, for caprocks in the brittle deformation stage, utilize fault displacement, sandstone connectivity, and sand-to-soil ratio to determine the sealing capacity. For the brittle-ductile deformation stage, evaluating the brittle-ductile transformation process requires establishing a quantitative characterization of the process through triaxial compression tests, acoustic emission characteristics, microscopic deformation mechanisms, and structural deformation characteristics within the caprock. For diagenetic evolution-type sealing caprocks, diagenetic evolution is further subdivided based on traditional burial physical compaction, chemical diagenesis, metamorphic stages, and uplift stages, and the sealing capacity is analyzed in conjunction with the evolution process. Existing technologies cannot meet the evaluation requirements for the sealing capacity of caprocks with different diagenesis degrees and varying brittleness-ductility. This disclosure provides a caprock sealing capacity evaluation method that can evaluate the sealing capacity of caprocks with different diagenesis degrees and varying brittleness-ductility. Figure 1 As shown, the capping layer sealing evaluation method of this disclosure includes:
[0058] 101. Test samples of the caprock in the target area to obtain the correlation between the caprock's confining pressure and permeability.
[0059] The target region is the folded deformation area to be analyzed. The sample can be a cylindrical caprock sample extracted from the borehole using a coring tool. The permeability is the permeability of the caprock in the target region. The correlation indicates the relationship between the confining pressure borne by the caprock in the target region and the permeability of the caprock.
[0060] In this step, core data of the caprock in the target area are collected, and a sealing test is conducted on the caprock core samples in the target area. During the test, the caprock core samples in the target area are continuously pressurized to simulate deep burial conditions of the strata, and the permeability under each confining pressure is recorded. Based on the geodynamic method, the relationship between the confining pressure and permeability of the target area is obtained from the recorded data.
[0061] 102. Calculate the permeability of the caprock based on the confining pressure and correlation of the caprock, so as to evaluate the sealing performance of the caprock in the target area based on the permeability.
[0062] Since permeability reflects the sealing performance of the caprock, lower permeability indicates better sealing performance, and vice versa. Therefore, embodiments of this disclosure utilize permeability to evaluate the sealing performance of the caprock.
[0063] In this step, the confining pressure of the caprock in the target area is obtained, and the confining pressure is substituted into the relational formula to calculate the permeability of the caprock in the target area.
[0064] This disclosure presents an embodiment that tests samples of the caprock in a target area, simulating deep burial conditions, to obtain the correlation between the confining pressure and permeability of the caprock. Based on the confining pressure of the target area and this correlation, the permeability of the caprock in the target area is obtained. By analyzing the permeability, the caprock sealing performance of the target area is evaluated. This disclosure presents a breakthrough in the difficulty of caprock sealing performance evaluation in complex folded deformation zones of foreland basins. It uses geodynamic methods to construct a correlation between confining pressure and permeability. Since the correlation differs for different caprock formations, this disclosure can be used to evaluate caprock sealing performance regardless of whether the caprock is in a brittle, brittle-ductile, or ductile arbitrary deformation stage, or regardless of the degree of diagenesis. This disclosure presents an embodiment with good versatility, improving the universality of caprock sealing performance evaluation methods compared to existing technologies. It also achieves quantitative evaluation and accurate prediction of caprock sealing performance in fold-thrust structural zones, providing important support for natural gas reserve exploration and well location deployment. The embodiments disclosed herein can be applied to the research on oil and gas exploration, evaluation and development in folded deformation zones, and can evaluate the risk of gas reservoir traps, especially for the sealing capacity of different types of caprocks, which can achieve universal evaluation.
[0065] To illustrate in more detail the caprock sealing evaluation method proposed in this disclosure, this disclosure provides an embodiment of another caprock sealing evaluation method. The specific implementation steps of the embodiment of this disclosure are as follows: Figure 2 As shown, it includes:
[0066] 201. Simulate deep burial conditions and apply multiple pressures to core samples from the caprock of the target area in a closed environment.
[0067] In this step, dynamic simulation experiments of confining pressure and permeability are conducted on the caprock core samples of the target area. The deep burial conditions of the strata are simulated in a closed environment, and the caprock core samples are continuously pressurized to simulate the caprock core samples being subjected to different confining pressures.
[0068] 202. The permeability of the caprock core samples under different confining pressures was measured, and the first data table was obtained.
[0069] The first data table records the permeability corresponding to different confining pressures.
[0070] In this embodiment, the caprock core sample is pressurized multiple times, so that the caprock core sample is subjected to different confining pressures. In this step, the permeability measured under different confining pressures is recorded to obtain the first data table.
[0071] 203. Generate a curve of confining pressure versus permeability based on the first data table.
[0072] The confining pressure versus permeability curve is used to illustrate the linear relationship between confining pressure and permeability.
[0073] In this step, a two-dimensional coordinate axis is established, with the horizontal axis representing confining pressure and the vertical axis representing permeability. Data from the first data table is marked on this two-dimensional coordinate axis to obtain multiple coordinate points. Based on all coordinate points, a confining pressure versus permeability curve is fitted to generate a confining pressure versus permeability curve graph. This graph can be used to show the trend of permeability of the caprock in the target area changing with confining pressure.
[0074] 204. The correlation between the confining pressure and permeability of the caprock was calculated based on the confining pressure and permeability curve.
[0075] The relationship between the confining pressure and permeability of the caprock is exponential, and this relationship includes a correction coefficient. Different caprocks have different correction coefficients; that is, caprocks with different degrees of diagenesis or different levels of brittleness and toughness have different correction coefficients. This disclosure utilizes the correction coefficient to evaluate the sealing properties of various caprocks.
[0076] In this step, based on the geodynamic method, the correlation between the confining pressure and permeability of the caprock in the target area is determined by analyzing the confining pressure and permeability curve. The relationship is expressed as follows:
[0077] P = a * e -bk
[0078] Where P is the confining pressure in MPa, k is the permeability in mD, a and b are correction coefficients, and e is the natural constant.
[0079] For example, such as Figure 3As shown in the diagram, the curve in the confining pressure vs. permeability graph illustrates an exponential relationship between confining pressure and permeability. The formula for this curve, obtained through calculation, is y = 44.745 * e. -0.033x Where x is the permeability, y is the confining pressure, and 44.745 and 0.033 are the correction coefficients for this region.
[0080] This disclosure utilizes a correction coefficient to evaluate the sealing capacity of caprocks with varying degrees of diagenesis and brittleness / ductility. The caprock sealing capacity evaluation method of this disclosure has good versatility. Furthermore, this disclosure requires few parameters for caprock sealing capacity calculation; only the confining pressure and permeability of the target area need to be measured to evaluate caprock sealing capacity. Because this disclosure uses fewer design parameters for caprock sealing capacity evaluation, it significantly improves the computational efficiency of caprock sealing capacity evaluation. Moreover, the calculation parameters in this disclosure are all experimentally obtained data, eliminating human intervention and greatly reducing human-induced errors. This disclosure simulates underground caprock conditions through experiments, ensuring high accuracy and reliability of the experimental data.
[0081] 205. Determine the confining pressure of the caprock in the target area based on the current tectonic stress and stress field of the target area.
[0082] Among them, tectonic stress is the stress caused by geological tectonic activity, while present tectonic stress is the stress caused by current geological tectonic activity. The stress field is the stress field of the target region.
[0083] In this step, the confining pressure of the caprock in the target area is determined by analyzing the current tectonic stress and stress field changes in the target area. Alternatively, the magnitude of the confining pressure of the caprock in the target area can be determined by experiments or drilling.
[0084] It should be noted that the method in step 205 is not logically sequential to the method in step 204. In the method implemented in this disclosure, executing step 204 first and then step 205 is merely one specific implementation method. Therefore, when executing the method of this embodiment, the order of steps 204 and 205 can be selected as needed, and no limitation on the order is imposed here.
[0085] 206. Substitute the confining pressure into the relational formula to calculate the permeability of the caprock.
[0086] 207. Evaluate the caprock sealing of the target area based on permeability.
[0087] Permeability can indicate the sealing performance of a caprock. In this step, the caprock's sealing performance can be judged by determining the extreme permeability value. When the caprock's permeability is less than the extreme permeability value, the caprock's sealing performance in the target area can be determined. The extreme permeability value range varies for different basin lithologies, and can be determined by the oil test data of the corresponding area. Experimental tests have shown that the caprock's sealing performance is good when the permeability is less than 0.01 millidarcy in the southern margin of the Junggar Basin.
[0088] To illustrate in more detail the caprock sealing evaluation method proposed in this disclosure, the following describes the testing steps for caprock core samples in the target area. The specific steps are as follows:
[0089] Step 1: Obtain a core sample from any natural gas well cover layer in the target area.
[0090] In this embodiment of the disclosure, multiple natural gas wells are located in the target area. This embodiment can select a core sample from the caprock of any one natural gas well in the target area for testing. After testing the core sample from that caprock, the remaining core samples from the caprocks of the other natural gas wells are tested sequentially until all caprock core samples from all natural gas wells in the target area have been tested. Alternatively, this embodiment can select a subset of natural gas wells for testing based on the actual application scenario.
[0091] Step 2: Simulate deep burial conditions by repeatedly pressurizing the core sample in a closed environment.
[0092] In this step, a dynamic simulation experiment is conducted on the core sample of the natural gas well cap layer to simulate the deep burial conditions of the formation. The core sample of the cap layer is continuously pressurized in order to measure the permeability under different confining pressures and obtain the corresponding permeability change trend.
[0093] Step 3: Measure the permeability of the core sample under different confining pressures to obtain a second data table corresponding to the natural gas well.
[0094] The second data table contains the confining pressure and permeability data obtained from experiments on a core sample of a natural gas well cover layer in the target area.
[0095] In this step, the permeability of the caprock core samples under different confining pressures was measured, and the permeability corresponding to each confining pressure was recorded to obtain the second data table. The second data table, shown in Table 1, displays the permeability corresponding to different confining pressures.
[0096] Confining pressure (MPa) Permeability (millidas) 30 15.83 40 11.49 80 3.33 100 1.65 155 0.27 160 0.23 170 0.16 180 0.12 190 0.085 200 0.061 222.3 0.029 242.54 0.015 300 0.002
[0097] Table 1. Permeability-Containing Pressure Relationship in Caprock Closure Experiment
[0098] Step 4: Generate a confining pressure versus permeability curve based on multiple second data tables.
[0099] In this step, the data from all the second data tables can be merged into a single data table to obtain the first data table. A confining pressure versus permeability curve is then generated based on the first data table. Since the experimental data in this embodiment comes from all wells in the target area, it reduces data bias caused by testing only a single well. This embodiment further improves the accuracy of the data source, thereby improving the accuracy of caprock sealing evaluation.
[0100] Based on the above method, this disclosure provides a caprock sealing evaluation device to improve the versatility of caprock sealing evaluation. The embodiments of this device correspond to the foregoing method embodiments. For ease of reading, this embodiment will not repeat the details of the foregoing method embodiments one by one, but it should be clear that the device in this embodiment can implement all the contents of the foregoing method embodiments. Specifically, as follows... Figure 4 As shown, the device includes:
[0101] Test unit 31 is used to test the sample of the capping layer in the target area to obtain the correlation between the confining pressure and permeability of the capping layer;
[0102] The calculation unit 32 is used to calculate the permeability of the capping layer based on the confining pressure of the capping layer and the correlation relationship, so as to evaluate the sealing performance of the capping layer in the target area based on the permeability.
[0103] Furthermore, the test unit includes:
[0104] The testing module is used to perform pressure tests on core samples of the caprock in the target area to obtain confining pressure versus permeability curves.
[0105] The calculation module is used to calculate the correlation between the confining pressure and permeability of the caprock based on the confining pressure and permeability curve. The correlation includes a correction coefficient, which is different for different caprocks.
[0106] Furthermore, the testing module is specifically used for:
[0107] Simulating deep burial conditions, core samples from the caprock of the target area were subjected to multiple pressurizations in a closed environment;
[0108] The permeability of the caprock core samples under different confining pressures was measured to obtain the first data table;
[0109] Generate a curve of confining pressure versus permeability based on the first data table.
[0110] Furthermore, the testing module is also specifically used for:
[0111] Obtain core samples of the caprock from multiple natural gas wells in the target area;
[0112] Sealing pressure tests were conducted on caprock core samples from each natural gas well to obtain multiple second data tables;
[0113] Based on the multiple second data tables, a confining pressure versus permeability curve is generated.
[0114] Furthermore, the computing unit includes:
[0115] The confining pressure of the caprock in the target area is determined based on the current tectonic stress and stress field of the target area.
[0116] Substituting the confining pressure into the correlation formula, the permeability of the caprock is calculated. Further, the correlation formula is:
[0117] P = a * e -bk
[0118] Where P is the confining pressure in MPa, K is the permeability in mD, and a and b are correction coefficients.
[0119] Furthermore, this disclosure also provides a processor for running a program, wherein the program executes the above-described... Figure 1-3 The method for evaluating the sealing performance of the caprock as described in the paper.
[0120] Furthermore, this disclosure also provides a storage medium for storing a computer program, wherein the computer program, when running, controls the device where the storage medium is located to execute the above-described... Figure 1-3 The method for evaluating the sealing performance of the caprock as described in the paper.
[0121] Furthermore, embodiments of this disclosure provide an electronic device 4, such as... Figure 5 As shown, the device includes at least one processor 41, at least one memory 42 connected to the processor 41, and a bus 43; wherein the processor 41 and the memory 42 communicate with each other through the bus 43; the processor 41 is used to call program instructions in the memory 42 to execute the above-described capping closure evaluation method. The device in this article may be a server, PC, PAD, mobile phone, etc.
[0122] Furthermore, this disclosure also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program that initializes the inspection method steps of the network device as described above. Although this disclosure has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this disclosure.
Claims
1. A method for evaluating the closure property of a cap layer, characterized by, The method includes: Samples of the caprock in the target area were tested to obtain the correlation between the confining pressure and permeability of the caprock; Based on the confining pressure of the capping layer and the correlation, the permeability of the capping layer is calculated so as to evaluate the sealing performance of the capping layer in the target area based on the permeability.
2. The method of claim 1, wherein, Samples of the caprock in the target area were tested to obtain the correlation between the confining pressure and permeability of the caprock, including: Pressure tests were performed on core samples from the caprock of the target area to obtain confining pressure versus permeability curves. The correlation between the confining pressure and permeability of the caprock is calculated based on the confining pressure and permeability curve. The correlation includes a correction coefficient, which is different for different caprocks.
3. The method of claim 2, wherein, Core samples from the caprock in the target area were subjected to pressure tests to obtain confining pressure versus permeability curves, including: Simulating deep burial conditions, core samples from the caprock of the target area were subjected to multiple pressurizations in a closed environment; The permeability of the core sample was measured under different confining pressures to obtain the first data table; Generate a curve of confining pressure versus permeability based on the first data table.
4. The method according to claim 2, characterized in that, Core samples from the caprock in the target area were subjected to pressure tests to obtain confining pressure versus permeability curves, including: Obtain core samples of the caprock from multiple natural gas wells in the target area; Each core sample was subjected to a closed-loop pressure test, resulting in multiple second data tables. Based on the multiple second data tables, a confining pressure versus permeability curve is generated.
5. The method according to claim 1, characterized in that, Calculate the permeability of the caprock based on the confining pressure and the correlation, including: The confining pressure of the caprock in the target area is determined based on the current tectonic stress and stress field of the target area. Substituting the confining pressure into the relational formula, the permeability of the capping layer is calculated.
6. The method according to any one of claims 1-5, characterized in that, The relational expression for the association is: P = a * e -bk Where P is the confining pressure in MPa, K is the permeability in mD, and a and b are correction coefficients.
7. A capping layer sealing performance evaluation device, characterized in that, The device includes: The testing unit is used to test samples of the caprock in the target area to obtain the correlation between the confining pressure and permeability of the caprock. The calculation unit is used to calculate the permeability of the capping layer based on the confining pressure of the capping layer and the correlation relationship, so as to evaluate the sealing performance of the capping layer in the target area based on the permeability.
8. The apparatus according to claim 7, characterized in that, The test unit includes: The testing module is used to perform pressure tests on core samples of the caprock in the target area to obtain confining pressure versus permeability curves. The calculation module is used to calculate the correlation between the confining pressure and permeability of the caprock based on the confining pressure and permeability curve. The correlation includes a correction coefficient, which is different for different caprocks.
9. An electronic device, characterized in that, The device includes at least one processor, at least one memory and a bus connected to the processor; wherein the processor and the memory communicate with each other through the bus; the processor is used to call program instructions in the memory to execute the method as described in any one of claims 1-6.
10. A computer storage medium, characterized in that, The storage medium is used to store a computer program, wherein the computer program, when running, controls the device where the storage medium is located to execute the method described in any one of claims 1-6.