Method and device for predicting well logging porosity of tight sandstone, electronic equipment and computer readable storage medium
By analyzing the porosity and density relationship of core samples based on core tests, a porosity calculation formula was obtained, which solved the problem of inaccurate porosity calculation of dense sandstone reservoirs in conventional acoustic time difference logging curves, and achieved more accurate porosity prediction.
Patent Information
- Application Number
- CN202311646991.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-04
- Publication Date
- 2025-06-06
Smart Images
Figure CN120103455A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of rock physics research, and in particular, relates to a method and device for predicting the porosity of dense sandstone logging, an electronic device and a computer-readable storage medium. Background Art
[0002] The pores of reservoir rocks have always been a hot topic in seismic exploration. Reservoirs with more pores are often more likely to store oil and gas, so the accurate evaluation and prediction of porosity in seismic exploration has always been a key research task. How to effectively predict and determine the pore content of reservoir rocks provides a basis for reservoir prediction.
[0003] The method of determining porosity is generally through laboratory measurement and inversion of pore parameters through rock physics model methods. Calculating reservoir porosity from logging data is the basic content of quantitative logging evaluation. The accuracy of reservoir porosity calculation directly affects the reliability of subsequent reservoir evaluation. In well logging, the porosity content is generally calculated through sonic time difference logging curves, but the sonic time difference of actual formations is not only affected by the pore content, but also by the pore shape; the porosity of logging can also be calculated through rock physics models, such as the xu-white model suitable for sandstone and mudstone, but the rock physics model has many input parameters and is also regional, so it lacks universality. Summary of the invention
[0004] Ordos has well-developed tight sand reservoirs with rich oil and gas reserves, but the logging porosity interpretation curve cannot accurately reflect the true porosity of the formation. The porosity parameter of tight reservoirs is an important parameter for reservoir description, and there should be a suitable porosity calculation method for different regions and different lithologies. The most accurate way to obtain porosity is to test the core in the well. Therefore, the present invention proposes a logging porosity prediction method for the reservoir in the area based on the core test, which solves the problem of inaccurate porosity content calculation by conventional acoustic time difference logging curves in the area.
[0005] In order to achieve the above object, a first aspect of the present invention provides a method for predicting the porosity of tight sandstone logging, comprising the following steps:
[0006] The first step is to obtain porosity test data of core samples in the target area;
[0007] The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0008] The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0009] The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0010] Optionally, the linear correlation R between the porosity test data and density is 2 =0.9804.
[0011] Optionally, in the first step, the porosity test data is tested using an overburden porosity instrument test.
[0012] Optionally, the first step also includes: pre-processing the core sample.
[0013] Optionally, the preprocessing comprises the following steps:
[0014] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0015] Optionally, the core sample is a core sample of a dense sand reservoir.
[0016] Optionally, the target layer is a sandstone-mudstone layer.
[0017] A second aspect of the present invention provides a prediction device for tight sandstone well logging porosity, comprising:
[0018] A porosity test data acquisition module is used to acquire porosity test data of core samples in a target area;
[0019] The porosity test data and density intersection analysis module is used to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0020] The porosity calculation formula acquisition module is used to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0021] The porosity curve acquisition module is used to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0022] A third aspect of the present invention provides an electronic device, the electronic device comprising:
[0023] A memory storing executable instructions;
[0024] A processor runs the executable instructions in the memory to implement the method for predicting the porosity of tight sandstone logging.
[0025] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which implements the method for predicting the porosity of tight sandstone logging when executed by a processor.
[0026] The process method of the present invention is simple, and the formula obtained based on core testing is more in line with the actual lithology for tight sandstone reservoirs, eliminating the error caused by the conventional logging porosity calculation method, and can better simulate and calculate the formation porosity value of the well. At the same time, it also solves the complexity and multi-parameter multi-solution problems of using rock physics models to predict porosity.
[0027] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.
[0029] Figure 1 A schematic flow chart of a method for predicting the porosity of tight sandstone logging according to an embodiment of the present invention is shown.
[0030] Figure 2 A cross plot of core porosity and density according to an embodiment of the present invention is shown.
[0031] Figure 3 The porosity curves obtained by different prediction methods are shown, wherein: ① the porosity curve calculated by the formula of the present invention; ② the porosity curve calculated by the acoustic wave time difference; ③ the porosity of the well core analysis. DETAILED DESCRIPTION
[0032] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.
[0033] In order to achieve the above object, a first aspect of the present invention provides a method for predicting the porosity of tight sandstone logging, comprising the following steps:
[0034] The first step is to obtain porosity test data of core samples in the target area;
[0035] The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0036] The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0037] The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0038] The prediction of porosity is crucial in seismic reservoir prediction. Accurately predicting the porosity in the physical property-controlled rich formation means accurately obtaining the oil and gas-bearing area. However, the actual method of obtaining porosity from logging data often cannot accurately and effectively estimate the porosity. At the same time, there should be a suitable porosity calculation method for different regions and different lithologies, and the most accurate way to obtain porosity is to test the core in the well. Therefore, the present invention proposes a logging porosity prediction method for the tight sandstone reservoir in the Ordos Basin based on the core test, which solves the problem of inaccurate calculation of porosity content by conventional acoustic time difference logging curves in the logging data in the region, and provides a simpler, more economical and effective way to calculate the logging porosity.
[0039] Optionally, the linear correlation R between the porosity test data and density is 2 =0.9804.
[0040] Optionally, in the first step, the porosity test data is tested using an overburden porosity instrument test.
[0041] Optionally, the first step also includes: pre-processing the core sample.
[0042] Optionally, the preprocessing comprises the following steps:
[0043] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0044] Optionally, the core sample is a core sample of a dense sand reservoir.
[0045] Optionally, the target layer is a sandstone-mudstone layer.
[0046] A second aspect of the present invention provides a prediction device for tight sandstone well logging porosity, comprising:
[0047] A porosity test data acquisition module is used to acquire porosity test data of core samples in a target area;
[0048] The porosity test data and density intersection analysis module is used to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0049] The porosity calculation formula acquisition module is used to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0050] The porosity curve acquisition module is used to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0051] A third aspect of the present invention provides an electronic device, the electronic device comprising:
[0052] A memory storing executable instructions;
[0053] A processor runs the executable instructions in the memory to implement the method for predicting the porosity of tight sandstone logging.
[0054] A fourth aspect of the present invention provides a computer-readable storage medium storing a computer program, which implements the method for predicting the porosity of tight sandstone logging when executed by a processor.
[0055] Example 1
[0056] This embodiment provides a method for predicting the porosity of tight sandstone logging, using Figure 1 The process diagram shown includes the following steps:
[0057] The first step is to obtain porosity test data of core samples in the target area;
[0058] The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0059] The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0060] The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0061] Figure 2 The relationship between core test porosity and density is given.
[0062] According to an embodiment of the present invention, the linear correlation R between the porosity test data and the density 2 =0.9804.
[0063] According to an embodiment of the present invention, in the first step, the porosity test data is tested using an overburden porosity instrument test.
[0064] According to an embodiment of the present invention, the first step further includes: pre-processing the core sample.
[0065] According to an embodiment of the present invention, the preprocessing comprises the following steps:
[0066] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0067] According to an embodiment of the present invention, the core sample is a core sample of a dense sand reservoir.
[0068] According to an embodiment of the present invention, the target layer is a sandstone-mudstone layer.
[0069] According to the method of this embodiment, the formula obtained based on core testing is more in line with the actual lithology for tight sandstone reservoirs, eliminates the errors caused by conventional logging porosity calculation methods, and can better simulate and calculate the formation porosity value of the well. At the same time, it also solves the complexity of using rock physics models to predict porosity and the problems of multi-parameter and multi-solution.
[0070] Example 2
[0071] This embodiment provides a prediction device for tight sandstone well logging porosity, comprising:
[0072] A porosity test data acquisition module is used to acquire porosity test data of core samples in a target area;
[0073] The porosity test data and density intersection analysis module is used to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0074] The porosity calculation formula acquisition module is used to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0075] The porosity curve acquisition module is used to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0076] In some embodiments, the linear correlation between the porosity test data and the density is R2=0.9804.
[0077] In some embodiments, the porosity test data is tested using an overburden porosity instrument test.
[0078] In some embodiments, the method further includes: pre-processing the core sample.
[0079] In some embodiments, the pretreatment comprises the following steps:
[0080] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0081] In some embodiments, the core sample is a core sample of a tight sand reservoir.
[0082] In some embodiments, the target horizon is a sandstone-mudstone layer.
[0083] According to the device of this embodiment, the formula obtained based on core testing is more in line with the actual lithology for tight sandstone reservoirs, eliminating the errors caused by the conventional logging porosity calculation method, and can better simulate and calculate the formation porosity value of the well. At the same time, it also solves the complexity of using rock physics models to predict porosity and the problems of multi-parameter and multi-solution.
[0084] For other detailed descriptions and advantages of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.
[0085] Example 3
[0086] This embodiment provides an electronic device, including a memory and a processor.
[0087] A memory storing executable instructions;
[0088] The processor runs the executable instructions in the memory to implement a method for predicting the porosity of tight sandstone logging.
[0089] The prediction method of tight sandstone logging porosity includes the following steps:
[0090] The first step is to obtain porosity test data of core samples in the target area;
[0091] The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0092] The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0093] The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0094] In some embodiments, the linear correlation R between the porosity test data and the density is 2 =0.9804.
[0095] In some embodiments, the porosity test data is tested using an overburden porosity instrument test.
[0096] In some embodiments, the method further includes: pre-processing the core sample.
[0097] In some embodiments, the pretreatment comprises the following steps:
[0098] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0099] In some embodiments, the core sample is a core sample of a tight sand reservoir.
[0100] In some embodiments, the target horizon is a sandstone-mudstone layer.
[0101] Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may include, for example, a random access memory (RAM) and / or a cache memory (cache), etc. The non-volatile memory may include, for example, a read-only memory (ROM), a hard disk, a flash memory, etc.
[0102] The processor may be a central processing unit (CPU) or other forms of processing units with data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present invention, the processor is used to run the computer-readable instructions stored in the memory.
[0103] According to the electronic equipment of this embodiment, the formula obtained based on core testing is more in line with the actual lithology for tight sandstone reservoirs, eliminating the errors caused by conventional logging porosity calculation methods, and can better simulate and calculate the formation porosity value of the well. At the same time, it also solves the complexity and multi-parameter and multi-solution problems of using rock physics models to predict porosity.
[0104] For other detailed descriptions and advantages of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.
[0105] Example 4
[0106] This embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, a method for predicting the porosity of tight sandstone logging is implemented.
[0107] The prediction method of tight sandstone logging porosity includes the following steps:
[0108] The first step is to obtain porosity test data of core samples in the target area;
[0109] The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis;
[0110] The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density;
[0111] The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
[0112] In some embodiments, the linear correlation R between the porosity test data and the density is 2 =0.9804.
[0113] In some embodiments, the porosity test data is tested using an overburden porosity instrument test.
[0114] In some embodiments, the method further includes: pre-processing the core sample.
[0115] In some embodiments, the pretreatment comprises the following steps:
[0116] The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
[0117] In some embodiments, the core sample is a core sample of a tight sand reservoir.
[0118] In some embodiments, the target horizon is a sandstone-mudstone layer.
[0119] The computer-readable storage medium according to the embodiment of the present invention stores non-transitory computer-readable instructions, and when the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of the embodiments of the present invention are executed.
[0120] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tapes or mobile hard disks), media with built-in rewritable non-volatile memory (e.g., memory cards), and media with built-in ROM (e.g., ROM boxes).
[0121] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present invention.
[0122] According to the computer-readable storage medium of this embodiment, the formula obtained based on core testing is more in line with the actual lithology for tight sandstone reservoirs, eliminating the errors caused by conventional logging porosity calculation methods, and can better simulate and calculate the formation porosity value of the well. At the same time, it also solves the complexity of using rock physics models to predict porosity and the problems of multi-parameter and multi-solution.
[0123] For other detailed descriptions and advantages of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.
[0124] Example 5
[0125] In order to verify the effect of the method for predicting the porosity of tight sandstone by well logging of the present invention, the method proposed by the present invention was used to predict the reservoir porosity of Well A in the formation in the region.
[0126] Figure 3 Marked ① is the porosity curve calculated by the formula of the present invention, ② is the porosity curve calculated by the acoustic time difference, and ③ is the porosity of the well core analysis. It can be seen from the figure that the porosity calculated by the formula of the present invention and the porosity change trend of the well core analysis with depth are more consistent than the porosity curve calculated by the acoustic time difference, and can effectively characterize the porosity change trend in the medium and low porosity areas. The process method of the present invention is simple, and the formula obtained based on the core test is more in line with the actual lithology for tight sandstone reservoirs, eliminating the error caused by the conventional logging porosity calculation method, and can better simulate and calculate the formation porosity value of the well, while also solving the complexity and multi-parameter multi-solution problems of predicting porosity using rock physics models.
[0127] For other detailed descriptions of this exemplary embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.
[0128] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terms used herein are selected to best explain the principles of the embodiments, practical applications, or technical improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.
Claims
1. A method for predicting the porosity of tight sandstone by well logging. It is characterized in that The steps include: The first step is to obtain porosity test data of core samples in the target area; The second step is to obtain the relationship diagram between different porosity test data and density and perform intersection analysis; The third step is to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density; The fourth step is to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
2. The method for determining the porosity of tight sandstone logging according to claim 1, in, The linear correlation between the porosity test data and density R 2 =0.9804.
3. The method for predicting the porosity of tight sandstone logging according to claim 1, in, In the first step, the porosity test data is tested using a pressure-based porosity instrument.
4. The method for determining the porosity of tight sandstone logging according to claim 3, in, The first step also includes: pre-processing the core sample.
5. The method for determining the porosity of tight sandstone logging according to claim 4, in, The pre-processing comprises the following steps: The core samples are formulated into specifications suitable for the overburden porosity instrument test, placed in a drying oven for drying, and after drying, placed in a vacuum drying environment to cool and stabilize.
6. The method for determining the porosity of tight sandstone logging according to claim 1, in, The core sample is a core sample of a dense sand reservoir.
7. The method for determining the porosity of tight sandstone logging according to claim 1, in, The target layer is a sandstone-mudstone layer.
8. A prediction device for tight sandstone logging porosity, It is characterized in that include: A porosity test data acquisition module is used to acquire porosity test data of core samples in a target area; The porosity test data and density intersection analysis module is used to obtain the relationship diagram between different porosity test data and density and perform intersection analysis; The porosity calculation formula acquisition module is used to obtain the porosity calculation formula by linear fitting based on intersection analysis: P = -33.218D + 88.431, where P is porosity and D is density; The porosity curve acquisition module is used to apply the porosity calculation formula to the porosity calculation of the target layer to obtain the porosity curve of the target layer.
9. An electronic device, It is characterized in that The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method for predicting the tight sandstone logging porosity according to any one of claims 1-7.
10. A computer-readable storage medium, It is characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for predicting the tight sandstone logging porosity according to any one of claims 1 to 7 is implemented.