Low-porosity sandstone reservoir stratum discrimination method, device, equipment and medium

Abstract

The invention discloses a low-porosity sandstone reservoir stratum distinguishing method, device, equipment and medium, and relates to the technical field of petroleum and natural gas exploration. The current formation water resistivity of low-porosity sandstone is determined firstly, and then the current formation porosity of the low-porosity sandstone is determined according to the current interval transit time; determining the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity, and determining the current rock conduction efficiency of the low-porosity sandstone according to the current water saturation and the current formation porosity; and finally, based on the current pore throat radius and the current rock conductive efficiency, whether the reservoir stratum of the current low-porosity sandstone is a dominant reservoir stratum is judged, and the current pore throat radius and the current rock conductive efficiency of the low-porosity sandstone can be accurately determined through the current formation water resistivity and the current interval transit time. And further accurately judging whether the reservoir stratum of the current low-porosity sandstone is a dominant reservoir stratum or not.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas exploration, and in particular to a method, device, equipment and medium for distinguishing a low-porosity sandstone reservoir. Background Art

[0002] In the process of oil and gas exploration, reservoir classification and evaluation is an important technical means to predict and evaluate favorable oil and gas zones in the exploration area. Sandstone reservoirs are an important area of ​​oil and gas development in my country, and reservoir evaluation of low-porosity sandstone is a difficult point in oil and gas reservoir exploration. Due to the low porosity of low-porosity sandstone, the permeability is poor, and the correlation between porosity and permeability is not strong, making the traditional sandstone reservoir evaluation method no longer applicable. Summary of the invention

[0003] The purpose of the present invention is to provide a low-porosity sandstone reservoir identification method, device, equipment and medium, which can accurately determine the current pore throat radius and current rock conductivity of the low-porosity sandstone through the current formation water resistivity and the current acoustic wave time difference, and then accurately determine whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0004] In order to solve the above technical problems, the present invention provides a method for identifying low-porosity sandstone reservoirs, comprising:

[0005] Determine current formation water resistivity in low-porosity sandstones;

[0006] Determining the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference;

[0007] Determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity;

[0008] Determining the current rock conductivity efficiency of the low-porosity sandstone by the current water saturation and the current formation porosity;

[0009] Based on the current pore throat radius and the current rock conductivity efficiency, it is determined whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0010] Optionally, determining the current formation water resistivity of the low-porosity sandstone comprises:

[0011] Determine the current oil test data;

[0012] Determine the current mineralization and depth of formation water according to the current oil testing data;

[0013] The current formation water resistivity is determined based on the salinity and the depth.

[0014] Optionally, determining the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference includes:

[0015] Determine the porosity calculation model;

[0016] The current formation porosity is determined according to the porosity calculation model and the current acoustic wave time difference.

[0017] Optionally, determining the porosity calculation model includes:

[0018] Determine historical well logging data;

[0019] Determining a number of historical acoustic time differences based on the historical logging data;

[0020] Performing compaction correction on each of the historical acoustic wave time differences to obtain a number of corrected historical acoustic wave time differences;

[0021] Determining corresponding historical formation porosities according to the corrected historical acoustic wave time differences;

[0022] The corrected historical acoustic time differences and historical formation porosities are simulated to obtain the porosity calculation model.

[0023] Optionally, determining the current water saturation of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity includes:

[0024] Determine the current lithology coefficient, current cementation index and current saturation index through the current core data;

[0025] Determine the current formation resistivity based on the current well logging data;

[0026] The water saturation is determined based on the water saturation calculation formula, the current formation water resistivity, the current formation resistivity, the current formation porosity, the current lithology coefficient, the current cementation index and the current saturation index.

[0027] Optionally, determining the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity includes:

[0028] Determine the current formation resistivity based on the current well logging data;

[0029] The current pore throat radius is determined based on the pore throat radius calculation formula, the current formation resistivity, the current formation porosity and the current formation water resistivity.

[0030] Optionally, determining the current rock conductivity efficiency of the low-porosity sandstone by using the current water saturation and the current formation porosity includes:

[0031] Determine the current formation resistivity based on the current well logging data;

[0032] The current rock conductivity efficiency is determined based on a rock conductivity efficiency calculation formula, the current formation resistivity, the current formation porosity, the current formation water resistivity and the current water saturation.

[0033] Optionally, judging whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency includes:

[0034] Determine the standard correspondence between pore throat radius and rock electrical conductivity efficiency;

[0035] Determine whether the current pore throat radius and the corresponding current rock conductivity efficiency meet the standard corresponding relationship;

[0036] If the standard corresponding relationship is met, the reservoir of the current rock formation is determined to be a dominant reservoir;

[0037] If the standard corresponding relationship is not satisfied, the reservoir of the current rock formation is determined to be a non-dominant reservoir.

[0038] Optionally, the determination of the standard correspondence between the pore throat radius and the rock conductivity efficiency includes:

[0039] Determine a number of historical acoustic wave time differences and a number of historical formation resistivities based on historical logging data;

[0040] Determining a number of corresponding historical stratigraphic porosities according to each of the historical acoustic wave time differences;

[0041] Determine several historical formation water resistivities based on historical oil testing materials;

[0042] Determining a plurality of historical water saturations and a plurality of historical pore throat radii based on each of the historical formation porosities, each of the historical formation water resistivities, and each of the historical formation resistivities;

[0043] determining a number of historical rock electrical conductivity efficiencies based on each of the historical water saturations;

[0044] The corresponding relationship between each of the historical rock conductivity efficiencies and each of the historical pore throat radii is used as the standard corresponding relationship.

[0045] In order to solve the above technical problems, the present invention also provides a low-porosity sandstone reservoir identification device, comprising:

[0046] A first determination unit is used to determine the current formation water resistivity of the low-porosity sandstone;

[0047] A second determination unit is used to determine the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference;

[0048] A third determination unit is used to determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity;

[0049] a fourth determination unit, configured to determine the current rock conductivity efficiency of the low-porosity sandstone according to the current water saturation and the current formation porosity;

[0050] A judgment unit is used to judge whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency.

[0051] In order to solve the above technical problems, the present invention further provides an electronic device, comprising:

[0052] Memory for storing computer programs;

[0053] A processor is used to implement the steps of the method for distinguishing low-porosity sandstone reservoirs as described above when executing the computer program.

[0054] In order to solve the above technical problems, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for identifying a low-porosity sandstone reservoir as described above are implemented.

[0055] The purpose of the present invention is to provide a low-porosity sandstone reservoir identification method, device, equipment and medium, first determine the current formation water resistivity of the low-porosity sandstone, then determine the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference, and then determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity, and determine the current rock conductivity efficiency of the low-porosity sandstone through the current water saturation and the current formation porosity, and finally determine whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency. The current pore throat radius and the current rock conductivity efficiency of the low-porosity sandstone can be accurately determined through the current formation water resistivity and the current acoustic wave time difference, and then accurately determine whether the current low-porosity sandstone reservoir is a dominant reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0057] Figure 1A process flow chart of a method for identifying a low-porosity sandstone reservoir provided by the present invention;

[0058] Figure 2 A process flow chart of another low-porosity sandstone reservoir identification method provided by the present invention;

[0059] Figure 3 A schematic diagram of the structure of a cross-plot of pore throat radius and rock conductivity efficiency provided by the present invention;

[0060] Figure 4 A schematic diagram of the structure of a low-porosity sandstone reservoir identification device provided by the present invention;

[0061] Figure 5 The present invention provides a schematic structural diagram of an electronic device. DETAILED DESCRIPTION

[0062] The core of the present invention is to provide a method, device, equipment and medium for distinguishing low-porosity sandstone reservoirs, which can accurately determine the current pore throat radius and current rock conductivity efficiency of the low-porosity sandstone through the current formation water resistivity and the current acoustic wave time difference, and then accurately judge whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0063] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0064] Please refer to Figure 1 , Figure 1 A process flow chart of a low-porosity sandstone reservoir identification method provided by the present invention. The method comprises:

[0065] S10: Determine the current formation water resistivity of low-porosity sandstone;

[0066] S11: determining the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference;

[0067] S12: determining the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity;

[0068] S13: determining the current rock conductivity efficiency of the low-porosity sandstone by the current water saturation and the current formation porosity;

[0069] S14: Based on the current pore throat radius and the current rock conductivity efficiency, determine whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0070] In the present invention, because it is necessary to judge whether the current low-porosity sandstone reservoir is a dominant reservoir by the current pore throat radius and the current rock conductivity efficiency, it is necessary to first determine the current pore throat radius and the current rock conductivity efficiency. To determine the pore throat radius, the current formation water resistivity and the current formation porosity of the low-porosity sandstone must first be determined, wherein the current formation porosity is determined based on the current acoustic wave time difference. In addition, to determine the rock conductivity efficiency, it is necessary to determine the current water saturation and the current formation porosity. The current water saturation and the current pore throat radius of the low-porosity sandstone can be determined based on the current formation water resistivity and the current formation porosity. By determining the current pore throat radius and the current rock conductivity efficiency, it is possible to accurately judge whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0071] It should be noted that most researchers classify reservoirs based on the results of thin section observations, capillary pressure experiments, and reservoir rock property statistics: through the study of the pore structure of the Jurassic reservoirs in the northwest margin of the Junggar Basin, it is concluded that the reservoirs can be divided into four types; by analyzing the pore types and reservoir characteristics of the CK oilfield in Iran, the reservoirs are divided into three categories and six subcategories.

[0072] Fractal geometry is a mathematical discipline that was developed in the late 1970s to study irregular geometric forms. Fractal is a general term for irregular structures and configurations with self-similarities, and is calibrated by fractal dimension. With the development of fractal geometry, many scholars have found that the fractal dimension of pore structure can be obtained by using capillary pressure curve data and applying fractal geometry principles, and then the pore structure of the reservoir can be quantitatively characterized: the fractal geometry formula for different pore distributions of rocks was derived, and the fractal dimension of different pore sizes was calculated using the segmented regression method. The reservoir was classified by combining the capillary pressure curve morphology and fractal theory, and it was verified that the larger the fractal dimension, the more complex the pore structure.

[0073] Mathematical algorithms have obvious advantages in reservoir classification and discrimination, and can quickly evaluate reservoirs in batches: With the enhancement of computer computing power and people's in-depth research and application of algorithms, a large number of statistical algorithms have begun to be applied in the field of geostatistics research. The grey correlation analysis method was applied to the reservoir rating of the Dongying Sag, and it was found that the magnitude of the reservoir quality evaluation parameters determined by the grey correlation method made the reservoir evaluation results more in line with the actual situation and highly reliable. The three methods of cluster analysis, fuzzy mathematical optimization and grey correlation analysis were applied to make reservoir evaluation more quantitative. Seven conventional logging curves were selected to establish a reservoir classification neural network model in data preprocessing. The vector machine technology was used to classify the reservoirs based on the flow unit classification. The information entropy-fuzzy spectrum clustering algorithm was used to divide the pore structure types of heterogeneous clastic rocks. Cluster analysis and grey correlation analysis were applied to the Chang 6 reservoir in the Jiyuan area for comprehensive evaluation. Combined with the sedimentary phase map, it was found that the high-quality reservoir zone was basically consistent with the geological understanding, proving the accuracy of mathematical algorithms in reservoir evaluation.

[0074] It should also be noted that the low-porosity sandstone reservoir identification method can also be summarized as step 1, fitting the relationship between the acoustic time difference and the core experimental porosity according to the regional core experimental data, and establishing a porosity calculation model suitable for the region; step 2, calculating the formation water resistivity according to the water analysis mineralization and depth in the oil test data; step 3, using the Archie formula to calculate the water saturation; step 4, calculating the rock conductivity efficiency; step 5, calculating the pore throat radius; step 6, establishing the intersection of the pore throat radius and the rock conductivity efficiency to achieve the identification of the dominant reservoir. The specific process is as follows Figure 2 shown.

[0075] The present embodiment provides a method for distinguishing a low-porosity sandstone reservoir, which first determines the current formation water resistivity of the low-porosity sandstone, then determines the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference, and then determines the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity, and determines the current rock conductivity efficiency of the low-porosity sandstone through the current water saturation and the current formation porosity, and finally determines whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency. The current pore throat radius and the current rock conductivity efficiency of the low-porosity sandstone can be accurately determined through the current formation water resistivity and the current acoustic wave time difference, and then accurately determines whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0076] Based on the above embodiments:

[0077] As an optional embodiment, determining the current formation water resistivity of low-porosity sandstone includes:

[0078] Determine the current oil test data;

[0079] Determine the current mineralization and depth of formation water based on current oil testing data;

[0080] Determine the current formation water resistivity based on salinity and depth.

[0081] In the present invention, the method for determining the current formation water resistivity of low-porosity sandstone is to first determine the current oil test data, then determine the current formation water mineralization and depth based on the current oil test data, and finally determine the current formation water resistivity based on the mineralization and depth, so as to accurately determine the current formation water resistivity.

[0082] As an optional embodiment, determining the current formation porosity of low-porosity sandstone according to the current acoustic wave time difference includes:

[0083] Determine the porosity calculation model;

[0084] The current formation porosity is determined based on the porosity calculation model and the current acoustic wave time difference.

[0085] In the present invention, the method for determining the current formation porosity of low-porosity sandstone according to the current acoustic wave time difference is to first determine the porosity calculation model, and then determine the current formation porosity according to the porosity calculation model and the current acoustic wave time difference, and accurately determine the current formation porosity through the porosity calculation model and the current acoustic wave time difference.

[0086] As an optional embodiment, determining the porosity calculation model includes:

[0087] Determine historical well logging data;

[0088] Determine a number of historical acoustic time differences based on historical logging data;

[0089] Compact and correct each historical acoustic wave time difference to obtain several corrected historical acoustic wave time differences;

[0090] Determine the corresponding several historical formation porosities according to the corrected historical acoustic wave time differences;

[0091] The corrected historical acoustic time differences and historical formation porosities are simulated and a porosity calculation model is obtained.

[0092] In the present invention, the method for determining the porosity calculation model is to first determine the historical logging data, then determine a number of historical acoustic wave time differences based on the historical logging data, and perform compaction correction on each historical acoustic wave time difference to obtain a number of corrected historical acoustic wave time differences, then determine the corresponding historical formation porosity based on each corrected historical acoustic wave time difference, and finally obtain the porosity calculation model based on the corrected historical acoustic wave time differences and their corresponding historical formation porosities, so as to accurately obtain the porosity calculation model and facilitate the subsequent determination of the formation porosity.

[0093] As an optional embodiment, the current water saturation of the low-porosity sandstone is determined according to the current formation water resistivity and the current formation porosity, including:

[0094] Determine the current lithology coefficient, current cementation index and current saturation index through the current core data;

[0095] Determine the current formation resistivity based on the current well logging data;

[0096] The water saturation is determined based on the water saturation calculation formula, the current formation water resistivity, the current formation resistivity, the current formation porosity, the current lithology coefficient, the current cementation index and the current saturation index.

[0097] In the present invention, the method for determining the current water saturation of low-porosity sandstone according to the current formation water resistivity and the current formation porosity is specifically to first determine the current lithology coefficient, the current cementation index and the current saturation index through the current core data, then determine the current formation resistivity according to the current well logging data, and finally substitute the current formation water resistivity, the current formation resistivity, the current formation porosity, the current lithology coefficient, the current cementation index and the current saturation index into the water saturation calculation formula to determine the water saturation, thereby improving the accuracy of the scheme.

[0098] It should be noted that water saturation S w The calculation formula is as follows:

[0099] Among them, S w is water saturation; R w is the formation water resistivity, Ω·m, obtained from core data; R t is the formation resistivity, Ω·m, obtained through logging data; φ is the formation porosity, obtained through core data; a is the lithology coefficient related to lithology, dimensionless, obtained through core rock electrical experiment; b is the constant related to lithology, dimensionless, obtained through core rock electrical experiment; m is the cementation index, dimensionless, obtained through core rock electrical experiment; n is the saturation index, dimensionless, obtained through core rock electrical experiment.

[0100] As an optional embodiment, determining the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity includes:

[0101] Determine the current formation resistivity based on the current well logging data;

[0102] The current pore throat radius is determined based on the pore throat radius calculation formula, the current formation resistivity, the current formation porosity and the current formation water resistivity.

[0103] In the present invention, the method for determining the current pore throat radius of low-porosity sandstone according to the current formation water resistivity and the current formation porosity is to first determine the current formation resistivity according to the current logging data, and then substitute the current formation resistivity, the current formation porosity and the current formation water resistivity into the pore throat radius calculation formula to determine the current pore throat radius, thereby ensuring the integrity of the scheme.

[0104] It should be noted that the calculation formula for the pore throat radius is:

[0105]

[0106] Where RCA is the pore throat radius; π is a constant, which is taken as 3.14159; R w is the formation water resistivity, Ω·m, obtained from core data; R t is the formation resistivity, Ω·m, obtained from well logging data; φ is the formation porosity, obtained from core data.

[0107] As an optional embodiment, the current rock conductivity efficiency of low-porosity sandstone is determined by the current water saturation and the current formation porosity, including:

[0108] Determine the current formation resistivity based on the current well logging data;

[0109] The current rock conductivity efficiency is determined based on the rock conductivity efficiency calculation formula, the current formation resistivity, the current formation porosity, the current formation water resistivity and the current water saturation.

[0110] In the present invention, the method for determining the current rock conductivity efficiency of low-porosity sandstone by using the current water saturation and the current formation porosity is to first determine the current formation resistivity according to the current logging data, and then convert the current

[0111] Substituting the formation resistivity, current formation porosity, current formation water resistivity and current water saturation into the rock conductivity efficiency calculation formula can obtain the current rock conductivity efficiency and accurately determine the current rock conductivity efficiency.

[0112] It should be noted that the calculation formula for rock conductivity efficiency is as follows: Where E is the rock conductivity efficiency; R w is the formation water resistivity, Ω·m, obtained from core data; R t is the formation resistivity, Ω·m, obtained from well logging data; S w is the water saturation, which is obtained by Archie's formula; φ is the formation porosity, which is obtained by core data.

[0113] As an optional embodiment, judging whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency includes:

[0114] Determine the standard correspondence between pore throat radius and rock electrical conductivity efficiency;

[0115] Determine whether the current pore throat radius and its corresponding current rock conductivity efficiency meet the standard corresponding relationship;

[0116] If the standard corresponding relationship is met, the reservoir of the current rock formation is determined to be the dominant reservoir;

[0117] If the standard corresponding relationship is not satisfied, the reservoir of the current rock formation is determined to be a non-dominant reservoir.

[0118] In the present invention, in order to judge whether the current low-porosity sandstone reservoir is a dominant reservoir, it is necessary to first determine the standard correspondence between the pore throat radius and the rock conductivity efficiency, and then judge the current pore throat radius and its corresponding current rock conductivity efficiency based on the standard correspondence between the pore throat radius and the rock conductivity efficiency. If the current pore throat radius and its corresponding current rock conductivity efficiency meet the standard correspondence, then the reservoir of the current rock formation is judged to be a dominant reservoir. If the current pore throat radius and its corresponding current rock conductivity efficiency do not meet the standard correspondence, then the reservoir of the current rock formation is judged to be a non-dominant reservoir, thereby accurately judging whether the current low-porosity sandstone reservoir is a dominant reservoir.

[0119] As an optional embodiment, determining the standard corresponding relationship between the pore throat radius and the rock electrical conductivity efficiency includes:

[0120] Determine a number of historical acoustic wave time differences and a number of historical formation resistivities based on historical logging data;

[0121] Determine the corresponding several historical stratigraphic porosities according to each historical acoustic wave time difference;

[0122] Determine several historical formation water resistivities based on historical oil testing materials;

[0123] Determining a number of historical water saturations and a number of historical pore throat radii based on each historical formation porosity, each historical formation water resistivity, and each historical formation resistivity;

[0124] Determine several historical rock conductivity efficiencies based on various historical water saturations;

[0125] The correspondence between the conductivity of each historical rock and the pore throat radius of each historical rock is taken as the standard correspondence.

[0126] In the present invention, the method for determining the standard corresponding relationship between the pore throat radius and the rock conductive efficiency is to determine a plurality of historical acoustic wave time differences and a plurality of formation resistivities according to historical logging data, then determine a plurality of corresponding historical formation porosities according to each historical acoustic wave time difference, determine a plurality of historical formation water resistivities according to historical oil testing materials, finally determine a plurality of water saturations and a plurality of historical pore throat radii according to each historical formation porosity and each historical formation water resistivity, determine a plurality of historical rock conductive efficiencies according to each historical water saturation, and finally use the corresponding relationship between each historical rock conductive efficiency and each historical pore throat radius as the standard corresponding relationship, thereby accurately obtaining the standard corresponding relationship between the pore throat radius and the rock conductive efficiency.

[0127] It should be noted that the historical water saturation is determined by historical core data, historical formation porosity, historical formation resistivity and historical formation water resistivity; that is, the standard correspondence between pore throat radius and rock conductivity efficiency is obtained based on historical well logging data, historical oil testing materials and historical core data.

[0128] It should also be noted that in practical applications, after determining the conductivity efficiency of each historical rock and its corresponding historical pore throat radius, an intersection chart of pore throat radius and rock conductivity efficiency is constructed with pore throat radius as the ordinate and rock conductivity efficiency as the abscissa, and a standard curve is formed on the intersection chart based on the standard data points formed by each historical rock conductivity efficiency and its corresponding historical pore throat radius. When judging whether the current low-porosity sandstone reservoir is a dominant reservoir, it can be judged whether the current data points formed by the current pore throat radius and the current rock conductivity efficiency are in a standard correspondence with the standard curve, such as Figure 3 As shown, the relationship formula of the standard curve is: y=0.5025x+1.9991, x is the rock conductivity efficiency E, and y is the pore throat radius RCA.

[0129] Please refer to Figure 4 , Figure 4 The present invention provides a schematic diagram of the structure of a low-porosity sandstone reservoir identification device. The device includes:

[0130] A first determination unit 11 is used to determine the current formation water resistivity of the low-porosity sandstone;

[0131] A second determination unit 12 is used to determine the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference;

[0132] A third determination unit 13 is used to determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity;

[0133] A fourth determination unit 14 is used to determine the current rock conductivity efficiency of the low-porosity sandstone according to the current water saturation and the current formation porosity;

[0134] The judgment unit 15 is used to judge whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency.

[0135] The low-porosity sandstone reservoir identification device provided in this embodiment corresponds to the above method, so it has the same beneficial effects as the above method. Therefore, for the embodiments of the low-porosity sandstone reservoir identification device, please refer to the description of the embodiments of the method part, which will not be repeated here.

[0136] Please refer to Figure 5 , Figure 5 The present invention provides a schematic diagram of the structure of an electronic device. The electronic device includes:

[0137] A memory 20, used for storing computer programs;

[0138] The processor 21 is used to implement the steps of the above-mentioned low-porosity sandstone reservoir identification method when executing the computer program.

[0139] The electronic device provided in this embodiment may include but is not limited to a smart phone, a tablet computer, a laptop computer or a desktop computer.

[0140] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0141] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201, wherein, after the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the low-porosity sandstone reservoir identification method disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. Data 203 may include but is not limited to a low-porosity sandstone reservoir identification method, etc.

[0142] In some embodiments, the electronic device may further include a display screen 22 , an input / output interface 23 , a communication interface 24 , a power source 25 , and a communication bus 26 .

[0143] Those skilled in the art will understand that Figure 5 The structure shown in the figure does not constitute a limitation on the electronic device, and may include more or fewer components than shown in the figure.

[0144] The purpose of this embodiment is to provide an electronic device, in which the memory 20 is used to store computer programs, and the processor 21 is used to implement the steps of the above-mentioned low-porosity sandstone reservoir identification method when executing the computer program, so that the identification process is more efficient and accurate.

[0145] The present invention also provides an embodiment corresponding to a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the method for distinguishing a low-porosity sandstone reservoir are implemented.

[0146] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the methods of each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0147] The computer-readable storage medium provided in this embodiment corresponds to the above method, and therefore has the same beneficial effects as the above method. Therefore, for the embodiments of the computer-readable storage medium part, please refer to the description of the embodiments of the method part, which will not be repeated here.

[0148] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0149] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for identifying low-porosity sandstone reservoirs, characterized in that: include: Determine current formation water resistivity in low-porosity sandstones; Determining the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference; Determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity; Determining the current rock conductivity efficiency of the low-porosity sandstone by the current water saturation and the current formation porosity; Based on the current pore throat radius and the current rock conductivity efficiency, it is determined whether the current low-porosity sandstone reservoir is a dominant reservoir.

2. The method for identifying low-porosity sandstone reservoirs according to claim 1, characterized in that: The method of determining the current formation water resistivity of low-porosity sandstone comprises: Determine the current oil test data; Determine the current mineralization and depth of formation water according to the current oil testing data; The current formation water resistivity is determined based on the salinity and the depth.

3. The method for identifying low-porosity sandstone reservoirs according to claim 1, characterized in that: The method of determining the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference comprises: Determine the porosity calculation model; The current formation porosity is determined according to the porosity calculation model and the current acoustic wave time difference.

4. The method for identifying low-porosity sandstone reservoirs according to claim 3, characterized in that: The method of determining the porosity calculation model comprises: Determine historical well logging data; Determining a number of historical acoustic time differences based on the historical logging data; Performing compaction correction on each of the historical acoustic wave time differences to obtain a number of corrected historical acoustic wave time differences; Determining corresponding historical formation porosities according to the corrected historical acoustic wave time differences; The corrected historical acoustic time differences and historical formation porosities are simulated to obtain the porosity calculation model.

5. The method for identifying low-porosity sandstone reservoirs according to claim 1, characterized in that: Determining the current water saturation of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity includes: Determine the current lithology coefficient, current cementation index and current saturation index through the current core data; Determine the current formation resistivity based on the current well logging data; The water saturation is determined based on the water saturation calculation formula, the current formation water resistivity, the current formation resistivity, the current formation porosity, the current lithology coefficient, the current cementation index and the current saturation index.

6. The method for identifying low-porosity sandstone reservoirs according to claim 1, characterized in that: Determining the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity includes: Determine the current formation resistivity based on the current well logging data; The current pore throat radius is determined based on the pore throat radius calculation formula, the current formation resistivity, the current formation porosity and the current formation water resistivity.

7. The method for identifying low-porosity sandstone reservoirs according to claim 1, characterized in that: The determining the current rock conductivity efficiency of the low-porosity sandstone by the current water saturation and the current formation porosity comprises: Determine the current formation resistivity based on the current well logging data; The current rock conductivity efficiency is determined based on a rock conductivity efficiency calculation formula, the current formation resistivity, the current formation porosity, the current formation water resistivity and the current water saturation.

8. The method for identifying a low-porosity sandstone reservoir according to any one of claims 1 to 7, characterized in that: The determining whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency includes: Determine the standard correspondence between pore throat radius and rock electrical conductivity efficiency; Determine whether the current pore throat radius and the corresponding current rock conductivity efficiency meet the standard corresponding relationship; If the standard corresponding relationship is met, the reservoir of the current rock formation is determined to be a dominant reservoir; If the standard corresponding relationship is not satisfied, the reservoir of the current rock formation is determined to be a non-dominant reservoir.

9. The method for identifying low-porosity sandstone reservoirs according to claim 8, characterized in that: The standard corresponding relationship between the pore throat radius and the rock conductivity efficiency is determined as follows: Determine a number of historical acoustic wave time differences and a number of historical formation resistivities based on historical logging data; Determining a number of corresponding historical stratigraphic porosities according to each of the historical acoustic wave time differences; Determine several historical formation water resistivities based on historical oil testing materials; Determining a plurality of historical water saturations and a plurality of historical pore throat radii based on each of the historical formation porosities, each of the historical formation water resistivities, and each of the historical formation resistivities; determining a number of historical rock electrical conductivity efficiencies based on each of the historical water saturations; The corresponding relationship between each of the historical rock conductivity efficiencies and each of the historical pore throat radii is used as the standard corresponding relationship.

10. A low-porosity sandstone reservoir identification device, characterized in that: include: A first determination unit is used to determine the current formation water resistivity of the low-porosity sandstone; A second determination unit is used to determine the current formation porosity of the low-porosity sandstone according to the current acoustic wave time difference; A third determination unit is used to determine the current water saturation and the current pore throat radius of the low-porosity sandstone according to the current formation water resistivity and the current formation porosity; a fourth determination unit, configured to determine the current rock conductivity efficiency of the low-porosity sandstone according to the current water saturation and the current formation porosity; A judgment unit is used to judge whether the current low-porosity sandstone reservoir is a dominant reservoir based on the current pore throat radius and the current rock conductivity efficiency.

11. An electronic device, characterized in that: include: Memory for storing computer programs; A processor is used to implement the steps of the low-porosity sandstone reservoir identification method as described in any one of claims 1 to 9 when executing the computer program.

12. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method for identifying a low-porosity sandstone reservoir as claimed in any one of claims 1 to 9 are implemented.

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