Method, device and equipment for determining fluid property of dolomitic mudstone reservoir and medium

Abstract

The invention discloses a dolomitic mudstone reservoir fluid property determination method, device and equipment and a medium, and is applied to the field of exploration. The dolomitic mudstone reservoir fluid property determination method provided by the invention comprises the following steps: performing resistivity detection on a to-be-detected dolomitic mudstone reservoir to obtain a resistivity data set; determining a resistivity abnormal value according to the resistivity data set; determining a resistivity median according to the resistivity data set and the resistivity abnormal value; determining a reservoir space evaluation factor according to the resistivity median and the resistivity characteristic value; and comprehensively analyzing the reservoir space evaluation factor, the resistivity median and the resistivity characteristic value to determine the fluid property of the dolomitic mudstone reservoir to be detected. According to the method, the fluid property of the dolomitic mudstone reservoir to be tested is obtained by comprehensively analyzing and judging three groups of data including the obtained reservoir space evaluation factor, the resistivity median and the resistivity characteristic value, the problem that the fracture-cavity reservoir cannot be accurately evaluated by conventional logging information is solved, and effective and accurate evaluation of the reservoir space is realized.

Description

Technical Field

[0001] This application relates to the field of exploration, and in particular to a method, apparatus, equipment and medium for determining the fluid properties of dolomitic mudstone reservoirs. Background Technology

[0002] With the deepening of exploration and development, unconventional oil and gas reservoirs have gradually gained attention. Dolomitic mudstone reservoirs, as a type of unconventional oil and gas reservoir, have proven reserves of over one million tons in a certain oilfield, with industrial oil flows obtained from more than ten wells. Therefore, dolomitic mudstone reservoirs have become a key focus of oilfield exploration. These reservoirs are typically good source rocks with high organic carbon content, averaging 2.41%–4.07%, and possess favorable hydrocarbon generation environments. Their rock composition is mainly argillaceous and carbonate, commonly containing pyrite, and also includes gypsum, quartz, and silica, with argillaceous content ranging from 50% to 57%. Overall, they are characterized by a diverse and complex rock composition and high argillaceous content. Furthermore, the reservoir space is complex, containing not only intergranular pores but also developed fractures and cavities; when the dolomitic content is high, karst caves develop; while when the argillaceous content is high, fractures develop.

[0003] In recent years, in the exploration and development of dolomitic mudstone reservoirs with integrated source and reservoir structures, only a small number of special oilfields have been able to use methods such as electrical imaging and nuclear magnetic resonance (NMR) to evaluate their reservoir space and fluid properties. For most oilfields, conventional logging methods can only be used, that is, the evaluation of reservoir space and fluid properties based on carbonate reservoir evaluation models and Archie's formula. However, due to the influence of multiple factors such as variable rock composition, high mud content, and complex reservoir space, the evaluation of conventional logging methods cannot accurately identify fluid properties, often resulting in situations where "the interpreted oil layer produces water, and the water layer produces oil," which cannot meet the production needs of such unconventional oil and gas reservoirs.

[0004] Given the above-mentioned technologies, finding a method for evaluating the fluid properties of dolomitic mudstone reservoirs is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] The purpose of this application is to provide a method, apparatus, equipment, and medium for determining the fluid properties of dolomitic mudstone reservoirs. This can solve the problem that conventional logging methods in the prior art cannot accurately identify fluid properties.

[0006] To address the aforementioned technical problems, this application provides a method for determining the fluid properties of dolomitic mudstone reservoirs, comprising:

[0007] Resistivity detection was performed on the dolomitic mudstone reservoir to obtain resistivity data.

[0008] Identify resistivity anomalies based on resistivity data sets;

[0009] Determine the median resistivity based on resistivity data sets and resistivity outliers;

[0010] The evaluation factors for storage space are determined based on the median resistivity and the characteristic resistivity.

[0011] A comprehensive analysis of reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​was conducted to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

[0012] Preferably, determining resistivity anomalies based on resistivity data sets includes:

[0013] Determine the upper and lower quartiles of resistivity based on resistivity data;

[0014] The upper and lower limits of resistivity are determined based on the upper and lower quartiles of resistivity.

[0015] Determine abnormal resistivity values ​​based on the upper and lower limits of resistivity;

[0016] The expression for the lower quartiles of resistivity is:

[0017] ;

[0018] ;

[0019] The expression for the upper quartiles of resistivity is:

[0020] ;

[0021] ;

[0022] The expression for the upper limit of resistivity is:

[0023] ;

[0024] The expression for the lower limit of resistivity is:

[0025] ;

[0026] Where Q1 is the lower quartile of resistivity, L(n) is a function, P1 is the value of the first process, P2 is the value of the second process, and Q... 上 Q is the upper limit of resistivity. 下 is the lower limit of resistivity; n is the number of resistivity data points.

[0027] Preferably, determining the median resistivity based on resistivity data sets and resistivity outliers includes:

[0028] Determine the target resistivity data set based on the resistivity data set and resistivity outliers;

[0029] Obtain the number of resistivity data points in the target resistivity data group, and sort the resistivity data points in the target resistivity data group in ascending order;

[0030] If the number of resistivity data is odd, then the expression for the median resistivity is:

[0031] If the number of resistivity data is even, then the expression for the median resistivity is: ;

[0032] Where R0 is the median resistivity, and n is the number of resistivity data points. For the n / 2th resistivity, For the (n / 2+1)th resistivity, It is the (n+1) / 2th resistivity.

[0033] Preferably, the evaluation factors for storage space are determined based on the median resistivity and the characteristic resistivity values, including:

[0034] Obtain resistivity characteristic values;

[0035] The ratio of resistivity characteristic value to resistivity median value is used as the evaluation factor for storage space.

[0036] Preferably, after determining the storage space evaluation factor based on the median resistivity and resistivity characteristic value, the method further includes:

[0037] A preliminary assessment of the dolomitic mudstone reservoir to be tested is made based on the reservoir space evaluation factors.

[0038] When the reservoir space evaluation factor is not less than the preset factor, the reservoir is initially determined to be a dry reservoir.

[0039] When the reservoir space evaluation factor is less than the preset factor, the reservoir is initially determined to be an effective reservoir. Effective reservoirs include oil layers, water layers, and oil-water co-layers.

[0040] Preferably, a comprehensive analysis is performed on the storage space evaluation factors, median resistivity, and resistivity characteristic values, including:

[0041] A cross plot of median resistivity and reservoir space evaluation factor is established based on median resistivity and reservoir space evaluation factor.

[0042] A cross plot of resistivity characteristic value and storage space evaluation factor is established based on resistivity characteristic value and storage space evaluation factor;

[0043] The fluid properties of the dolomitic mudstone reservoir to be tested were determined based on the cross plots of median resistivity and reservoir space evaluation factors and the cross plots of resistivity characteristic values ​​and reservoir space evaluation factors.

[0044] Preferably, the fluid properties of the dolomitic mudstone reservoir to be tested are determined based on the cross plots of median resistivity and reservoir space evaluation factors and the cross plots of resistivity characteristic values ​​and reservoir space evaluation factors, including:

[0045] If the resistivity characteristic value is less than the first characteristic value, the median resistivity is less than the first median value, and the reservoir space evaluation factor is less than the preset factor, then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be water-bearing.

[0046] If the resistivity characteristic value is not less than the first characteristic value and the resistivity characteristic value is less than the second characteristic value, the resistivity median is not less than the first median value and the resistivity characteristic value is less than the second median value, and the reservoir space evaluation factor is less than the preset factor, then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be oil-water co-layer.

[0047] If the resistivity characteristic value is not less than the second characteristic value, the median resistivity is not less than the second median value, and the reservoir space evaluation factor is less than the preset factor, then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be an oil layer.

[0048] To address the aforementioned technical problems, this application provides a device for determining the fluid properties of dolomitic mudstone reservoirs, comprising:

[0049] The detection module is used to detect the resistivity of the dolomitic mudstone reservoir under test in order to obtain resistivity data sets.

[0050] The outlier determination module is used to determine outlier resistivity values ​​based on the resistivity data set.

[0051] The median determination module is used to determine the median resistivity based on resistivity data sets and resistivity outliers.

[0052] The evaluation factor determination module is used to determine the evaluation factors of the storage space based on the median resistivity and the characteristic value of resistivity.

[0053] The determination module is used to comprehensively analyze the reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

[0054] To address the aforementioned technical problems, this application also provides an electronic device, including a memory for storing computer programs;

[0055] A processor is used to implement the steps of the above-described method for determining the fluid properties of dolomitic mudstone reservoirs when executing computer programs.

[0056] To address the aforementioned technical problems, this application also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the aforementioned method for determining the fluid properties of dolomitic mudstone reservoirs.

[0057] This application provides a method for determining the fluid properties of dolomitic mudstone reservoirs, comprising: conducting resistivity detection on the dolomitic mudstone reservoir to be tested to obtain a resistivity data set; determining resistivity anomalies based on the resistivity data set; determining the median resistivity based on the resistivity data set and the resistivity anomalies; determining reservoir space evaluation factors based on the median resistivity and resistivity characteristic values; and comprehensively analyzing the reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​to determine the fluid properties of the dolomitic mudstone reservoir to be tested. It is evident that this application comprehensively analyzes and judges the fluid properties of the dolomitic mudstone reservoir to be tested using three sets of data: reservoir space evaluation factors, median resistivity, and resistivity characteristic values. This solves the problem that conventional well logging data cannot accurately evaluate fractured-vuggy reservoirs, achieving effective and accurate evaluation of reservoir space. Attached Figure Description

[0058] To more clearly illustrate the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0059] Figure 1 A flowchart illustrating a method for determining fluid properties in dolomitic mudstone reservoirs, provided as an embodiment of this application;

[0060] Figure 2 The oil reservoir radar image provided for the embodiments of this application;

[0061] Figure 3 This application provides an example of an oil-water co-layer radar image.

[0062] Figure 4 Water layer radar image provided for embodiments of this application;

[0063] Figure 5 Dry layer radar image provided for embodiments of this application;

[0064] Figure 6 This is a box-shaped structural diagram provided in the embodiments of this application;

[0065] Figure 7 A well logging combination diagram of well X26 provided in an embodiment of this application;

[0066] Figure 8 A resistivity ranking table of adjacent layers in well X26 provided for embodiments of this application;

[0067] Figure 9 This is a first box plot of the oil-bearing layer end data of well X26 provided in an embodiment of this application;

[0068] Figure 10 This is a first box plot of the oil-bearing layer end data of well X26 provided in an embodiment of this application;

[0069] Figure 11 The calculation results of the evaluation value of the test oil layer in the Baiyinchagan Depression provided in the embodiments of this application;

[0070] Figure 12 Cross plot of resistivity characteristic values ​​and storage space evaluation factors provided for embodiments of this application;

[0071] Figure 13 Cross plot of median resistivity-storage space evaluation factor provided for embodiments of this application;

[0072] Figure 14 A well logging combination diagram of well C41 provided in an embodiment of this application;

[0073] Figure 15 The logging combination diagram of well X3-70 provided in the embodiments of this application;

[0074] Figure 16 A module diagram of a device for determining the fluid properties of dolomitic mudstone reservoirs, provided in another embodiment of this application;

[0075] Figure 17 A structural diagram of an electronic device provided in another embodiment of this application. Detailed Implementation

[0076] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of this application.

[0077] The core of this application is to provide a method, apparatus, equipment, and medium for determining the fluid properties of dolomitic mudstone reservoirs.

[0078] To enable those skilled in the art to better understand the present application, the present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0079] Figure 1 A flowchart of a method for determining the fluid properties of dolomitic mudstone reservoirs, provided for an embodiment of this application, is shown in the figure, including the following steps:

[0080] S10: Conduct resistivity detection on the dolomitic mudstone reservoir to be tested to obtain resistivity data sets.

[0081] In a specific embodiment, the first step is to analyze the reservoir resistivity using radar charts to establish resistivity radar charts for the oil layer, oil-water co-layer, water layer, and dry layer, respectively. Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, by analyzing the distribution characteristics of various reservoirs on the radar chart, the threshold values ​​of the corresponding reservoirs were determined. Specifically, the resistivity of oil-bearing reservoirs ranged from 20.0 to 107.0 Ω·m, the resistivity of oil-water co-layers ranged from 10.0 to 18.0 Ω·m, the resistivity of water-bearing reservoirs ranged from 3.0 to 8.5 Ω·m, and the resistivity of dry reservoirs ranged from 62.0 to 81.5 Ω·m. The analysis revealed that the better the oil content of the reservoir, the higher the resistivity.

[0082] Based on this, the resistivity of the dolomitic mudstone reservoir under test was measured using conventional logging methods. The resistivity data obtained were divided into resistivity data sets according to the different resistivities of different layers.

[0083] S11: Determine resistivity anomalies based on resistivity data sets.

[0084] In a specific embodiment, the resistivity data set is displayed using a box plot. The biggest advantage of a box plot is its insensitivity to outliers, thus it can accurately and stably depict the discrete distribution of the data, and is also beneficial for cleaning and characterizing discrete data. Therefore, using a box plot can identify resistivity outliers in the resistivity data set.

[0085] For example, the specific method for determining resistivity outliers is as follows: determine the upper quartile and lower quartile of resistivity based on the resistivity data; determine the upper limit and lower limit of resistivity based on the upper quartile and lower quartile; and determine resistivity outliers based on the upper limit and lower limit of resistivity.

[0086] S12: Determine the median resistivity based on the resistivity data set and resistivity outliers.

[0087] In a specific embodiment, the median (also known as the median value) refers to the value in the middle of a sequence of variables in a statistical population, arranged in ascending order. In this embodiment, the median resistivity characterizes the electrical properties of strata with similar hydrocarbon-generating environments and lithologies; therefore, the median resistivity is used as the background value for that stratum.

[0088] For example, the specific method for determining the median resistivity is as follows: determine the target resistivity data set based on the resistivity data set and resistivity outliers; obtain the number of resistivity data points in the target resistivity data set, and arrange the resistivity data points in the target resistivity data set in ascending order; if the number of resistivity data points is odd, the median resistivity is the value in the middle position of the arrangement; if the number of resistivity data points is even, the resistivity value is the average of the two values ​​in the middle position of the arrangement.

[0089] S13: Determine the storage space evaluation factor based on the median resistivity and resistivity characteristic value.

[0090] S14: A comprehensive analysis of reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​is conducted to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

[0091] In a specific embodiment, since the conventional resistivity value in fractures and cavities of dolomitic mudstone reservoirs decreases under stable conditions as fractures and cavities develop, this application proposes the concept of a reservoir space evaluation factor to make a preliminary judgment on the fluid properties of dolomitic mudstone reservoirs. That is, in practical applications, the reservoir space evaluation factor can be used to make a preliminary judgment on the dolomitic mudstone reservoir to be tested. When the reservoir space evaluation factor is not less than a preset factor, the reservoir is preliminarily determined to be a dry reservoir; when the reservoir space evaluation factor is less than the preset factor, the reservoir is preliminarily determined to be an effective reservoir. Among them, effective reservoirs include oil layers, water layers, and oil-water co-layers.

[0092] Based on this, in order to further determine the oil layer, water layer and oil-water co-layer in the effective reservoir, a comprehensive analysis of the reservoir space evaluation factor, median resistivity and resistivity characteristic value is carried out to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

[0093] For example: A resistivity-reservoir space evaluation factor cross plot is established based on the median resistivity and the reservoir space evaluation factor; a resistivity characteristic value-reservoir space evaluation factor cross plot is established based on the resistivity characteristic value and the reservoir space evaluation factor; when the resistivity characteristic value is less than the first characteristic value, the resistivity median is less than the first median, and the reservoir space evaluation factor is less than the preset factor, the fluid nature of the dolomitic mudstone reservoir to be tested is determined to be a water layer; when the resistivity characteristic value is not less than the first characteristic value, and the resistivity characteristic value is less than the second characteristic value, the resistivity median is not less than the first median, and the resistivity characteristic value is less than the second median, and the reservoir space evaluation factor is less than the preset factor, the fluid nature of the dolomitic mudstone reservoir to be tested is determined to be an oil-water co-layer; when the resistivity characteristic value is not less than the second characteristic value, the resistivity median is not less than the second median, and the reservoir space evaluation factor is less than the preset factor, the fluid nature of the dolomitic mudstone reservoir to be tested is determined to be an oil layer.

[0094] It should be noted that the example provided in this application is only one possible implementation method, but it is not the only possible implementation method. Users can set it themselves according to their needs.

[0095] This application provides a method for determining the fluid properties of dolomitic mudstone reservoirs, comprising: conducting resistivity detection on the dolomitic mudstone reservoir to be tested to obtain a resistivity data set; determining resistivity anomalies based on the resistivity data set; determining the median resistivity based on the resistivity data set and the resistivity anomalies; determining reservoir space evaluation factors based on the median resistivity and resistivity characteristic values; and comprehensively analyzing the reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​to determine the fluid properties of the dolomitic mudstone reservoir to be tested. It is evident that this application comprehensively analyzes and judges the fluid properties of the dolomitic mudstone reservoir to be tested using three sets of data: reservoir space evaluation factors, median resistivity, and resistivity characteristic values. This solves the problem that conventional well logging data cannot accurately evaluate fractured-vuggy reservoirs, achieving effective and accurate evaluation of reservoir space.

[0096] Based on the above embodiments, as a preferred embodiment, determining resistivity anomalies according to resistivity data sets includes:

[0097] Determine the upper and lower quartiles of resistivity based on resistivity data;

[0098] The upper and lower limits of resistivity are determined based on the upper and lower quartiles of resistivity.

[0099] Determine abnormal resistivity values ​​based on the upper and lower limits of resistivity;

[0100] The expression for the lower quartiles of resistivity is:

[0101] ;

[0102] ;

[0103] The expression for the upper quartiles of resistivity is:

[0104] ;

[0105] ;

[0106] The expression for the upper limit of resistivity is:

[0107] ;

[0108] The expression for the lower limit of resistivity is:

[0109] ;

[0110] Where Q1 is the lower quartile of resistivity, L(n) is a function, P1 is the value of the first process, P2 is the value of the second process, and Q... 上 Q is the upper limit of resistivity. 下 is the lower limit of resistivity; n is the number of resistivity data points.

[0111] In a specific implementation, a box plot is a statistical graph used to display the dispersion of a set of data. It can display the maximum, minimum, median, and upper and lower quartiles of a set of data. The biggest advantage of a box plot is that it is unaffected by outliers, accurately and stably depicting the discrete distribution of data. It also facilitates the cleaning and characterization of discrete data, such as... Figure 6 As shown. The lower quartile, upper quartile, upper limit, and lower limit of resistivity can be determined using the formulas provided in this application's embodiments. The abnormal resistivity values ​​are: Values ​​other than those mentioned above.

[0112] It should be noted that the formula provided in this application is only one possible method, but it is not the only one. Users can set it themselves according to their needs.

[0113] This application provides specific steps for determining resistivity anomalies based on resistivity data sets, and clarifies the formulas in the steps. According to the formulas provided in the embodiments of this application, resistivity anomalies can be quickly determined based on resistivity data sets, improving the accuracy of resistivity anomalies and laying the foundation for subsequent determination of the fluid properties of the dolomitic mudstone reservoir to be tested.

[0114] Based on the above embodiments, as a preferred embodiment, determining the median resistivity according to resistivity data sets and resistivity outliers includes:

[0115] Determine the target resistivity data set based on the resistivity data set and resistivity outliers;

[0116] Obtain the number of resistivity data points in the target resistivity data group, and sort the resistivity data points in the target resistivity data group in ascending order;

[0117] If the number of resistivity data is odd, then the expression for the median resistivity is:

[0118] If the number of resistivity data is even, then the expression for the median resistivity is: ;

[0119] Where R0 is the median resistivity, and n is the number of resistivity data points. For the n / 2th resistivity, For the (n / 2+1)th resistivity, It is the (n+1) / 2th resistivity.

[0120] In a specific embodiment, the resistivity data set of the segment to be characterized is processed by removing resistivity outliers according to the box plot distribution pattern to obtain the target resistivity data set. This target resistivity data set is then arranged in ascending order, and the median resistivity is redefined. If the number of resistivity data points n is odd, the median resistivity is the value in the middle of the arrangement, as shown in the formula above. If the number of resistivity data points n is even, the resistivity value is the average of the two values ​​in the middle of the arrangement, as shown in the formula above.

[0121] Among them, the evaluation factors for reservoir space are determined based on the median resistivity and the characteristic value of resistivity, including:

[0122] Obtain resistivity characteristic values;

[0123] The ratio of resistivity characteristic value to resistivity median value is used as the evaluation factor for storage space.

[0124] In a specific embodiment, since the conventional resistivity value in fractured cavities of dolomitic mudstone reservoirs decreases under stable conditions as fractures and cavities develop, this application proposes the concept of a reservoir space evaluation factor, wherein the expression for the reservoir space evaluation factor is: Where f is the storage space evaluation factor, and R t R is the characteristic value of resistivity, and R0 is the median resistivity.

[0125] It should be noted that the formula provided in this application is only one possible method, but it is not the only one. Users can set it themselves according to their needs.

[0126] This application provides specific steps and related formulas for determining the median resistivity based on resistivity data sets and resistivity outliers, and for determining reservoir space evaluation factors based on the median resistivity and resistivity characteristic values. The formulas provided in this application allow for the rapid acquisition of the median resistivity and reservoir space evaluation factors, improving data accuracy and laying the foundation for subsequent determination of the fluid properties of the dolomitic mudstone reservoir under test.

[0127] Based on the above embodiments, as a preferred embodiment, after determining the storage space evaluation factor according to the median resistivity and resistivity characteristic values, the method further includes:

[0128] A preliminary assessment of the dolomitic mudstone reservoir to be tested is made based on the reservoir space evaluation factors.

[0129] When the reservoir space evaluation factor is not less than the preset factor, the reservoir is initially determined to be a dry reservoir.

[0130] When the reservoir space evaluation factor is less than the preset factor, the reservoir is initially determined to be an effective reservoir. Effective reservoirs include oil layers, water layers, and oil-water co-layers.

[0131] In specific embodiments, in practical applications, the reservoir space evaluation factor can be used to make a preliminary judgment on the dolomitic mudstone reservoir to be tested. When the reservoir space evaluation factor (f) is not less than the preset factor (the preset factor has a value of 1), it indicates that the reservoir resistivity value in the strata with similar hydrocarbon generation environment and lithology has not decreased, the reservoir space is poor, and the lithology is relatively dense, so the reservoir is initially judged to be a dry layer. When the reservoir space evaluation factor (f) is less than the preset factor (the preset factor has a value of 1), it indicates that the reservoir resistivity value in the strata with similar hydrocarbon generation environment and lithology has decreased, and the reservoir space is better, so the reservoir is initially judged to be an effective reservoir. Among them, effective reservoirs include oil layers, water layers, and oil-water co-layers.

[0132] Preliminary assessments can only determine whether a reservoir is dry or effective, but cannot specifically identify oil layers, water layers, or oil-water co-containment layers within an effective reservoir. Since the median resistivity and characteristic resistivity values ​​in dolomitic mudstone reservoirs with integrated source and reservoir structures are positively correlated with the organic matter abundance of the source rock, and reservoir space evaluation factors reflect the quality of the reservoir's reservoir space, a comprehensive analysis of the median resistivity, characteristic resistivity values, and reservoir space evaluation factors can achieve accurate evaluation of the fluid properties of fractured-vuggy dolomitic mudstone reservoirs. By selectively establishing cross-plots of median resistivity versus reservoir space evaluation factors and characteristic resistivity versus reservoir space evaluation factors, accurate evaluation of the fluid properties of fractured-vuggy dolomitic mudstone reservoirs can be quickly achieved, solving the problem that conventional logging data cannot effectively evaluate the fluid properties of such reservoirs.

[0133] Specifically, determining the fluid properties of the dolomitic mudstone reservoir includes:

[0134] When the resistivity characteristic value R t If the fluid properties of the dolomitic mudstone reservoir to be tested are less than the first characteristic value (the first characteristic value is 9 Ω·m), the median resistivity R0 is less than the first median value (the first median value is 15 Ω·m), and the reservoir space evaluation factor f is less than the preset factor (the preset factor value is 1), then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be water-bearing.

[0135] When the resistivity characteristic value R t The resistivity characteristic value R0 is not less than the first characteristic value (the first characteristic value is 9 Ω·m), and the resistivity characteristic value R0 is less than the second characteristic value (the second characteristic value is 20 Ω·m). The median resistivity R0 is not less than the first median (the first median is 15 Ω·m), and the resistivity characteristic value R tIf the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be oil-water co-layers, and the reservoir space evaluation factor f is less than the second median (the second median is 40 Ω·m), and the reservoir space evaluation factor f is less than the preset factor (the preset factor value is 1), then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be oil-water co-layers.

[0136] When the resistivity characteristic value R t If the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be oil-bearing, the median resistivity R0 is not less than the second characteristic value (the second characteristic value is 20 Ω·m), the median resistivity R0 is not less than the second median value (the second median value is 40 Ω·m), and the reservoir space evaluation factor f is less than the preset factor (the preset factor value is 1).

[0137] It should be noted that the embodiments and specific values ​​provided in this application are only one possible implementation method, but are not limited to this only implementation method. Users can set them themselves according to their needs.

[0138] In summary, the above methods, when applied to real-world scenarios, involve the following steps:

[0139] (1) Analysis of resistivity characteristics of dolomitic mudstone reservoirs

[0140] Resistivity analysis of dolomitic mudstone reservoirs in the Baiyinchagan Depression, where oil testing has been confirmed, was conducted using radar images. Resistivity radar images of oil layers, oil-water co-layers, water layers, and dry layers were established respectively. Figure 2 , Figure 3 , Figure 4 , Figure 5 As can be seen from the radar chart, the resistivity of the oil layer is between 20.0 and 107.0 Ω·m, the resistivity of the oil-water co-layer is between 10.0 and 18.0 Ω·m, the resistivity of the water layer is between 3.0 and 8.5 Ω·m, and the resistivity of the dry layer is between 62.0 and 81.5 Ω·m. Analysis shows that the better the oil content of the reservoir, the higher the resistivity.

[0141] (2) Use the median value in the box plot to determine the median resistivity R0.

[0142] There are 30 dolomitic mudstone reservoirs in the Baiyinchagan Depression with confirmed oil testing results. Taking the X26 well oil layer as an example, the median resistivity R0 of the reservoir's adjacent layers is calculated. The resistivity values ​​from 1804.0 to 1822.0 m are selected to calculate the median resistivity R0. Figure 7 As shown.

[0143] Arrange the resistivity data sets selected within the X26 well interval in ascending order, such as... Figure 8 As shown, there are a total of 146 data points, i.e., n=146.

[0144] From the above formula and Figure 8From the data, we can obtain Q1=19.85 and Q3=102.82 respectively. According to the box plot calculation, the non-outlier values ​​are [-105.455, 227.275]. However, the resistivity value should not be less than 0, therefore the non-outlier values ​​should be [0, 227.275]. Thus, points 145 and 146 are outlier data points. Figure 9 As shown.

[0145] After removing the abnormal resistivity values ​​corresponding to the abnormal data points, there are 144 data points remaining, i.e., n=144.

[0146] From the above formula and Figure 8 From the data, the median resistivity, which characterizes the reservoir background, can be calculated as R0 = 40.01 Ω·m. Figure 10 As shown.

[0147] The median resistivity R0 of the 30 test oil layers was obtained using the method described above, and the specific values ​​are as follows: Figure 11 As shown.

[0148] (3) Calculation of storage space evaluation factors

[0149] The resistivity characteristic value R of 30 test oil layers was read respectively. t And using the above formulas, the storage space evaluation factors are calculated respectively. .

[0150] (4) Establishment of evaluation criteria for fractured-vuggy dolomitic mudstone reservoirs

[0151] Using the resistivity characteristic value R of the test oil layer t Based on the calculated median resistivity R0 of similar layers and the reservoir space evaluation factor f, resistivity characteristic values ​​R are established respectively. t - Storage space evaluation factor f cross plot, such as Figure 12 As shown; a cross plot of median resistivity R0 and storage space evaluation factor f, as shown. Figure 13 As shown.

[0152] Figure 12 and Figure 13 It is evident that the reservoir fluids exhibit different properties, with clear boundaries, and the resistivity characteristic value R t - Storage space evaluation factor f, median resistivity R t - The reservoir space evaluation factor f can be accurately evaluated by using two cross plots simultaneously.

[0153] Through cross-plot analysis, the criteria for identifying fluid properties in fractured-vuggy dolomitic mudstone reservoirs were clarified:

[0154] Oil layer: resistivity characteristic value R t≥20Ω·m, median resistivity R0≥40Ω·m, storage space evaluation factor f<1;

[0155] Oil and water in the same layer: resistivity characteristic value 9Ω·m≤R t <20Ω·m, median resistivity 15Ω·m≤R0<40Ω·m, storage space evaluation factor f<1;

[0156] Water layer: resistivity characteristic value R t <9Ω·m, median resistivity R0 <15Ω·m, storage space evaluation factor f <1;

[0157] Dry layer: f ≥ 1.

[0158] Specific Implementation Example 1: Layer 41 of Well C41, such as Figure 14 As shown, the lithology is dolomitic mudstone. The reservoir resistivity characteristic value R... t The resistivity is 18 Ω·m, which is relatively low. Using the median value in the box plot, the median resistivity R0 is determined to be 30 Ω·m. The calculated reservoir space evaluation factor f = 0.6; the spontaneous potential shows a significant negative anomaly; and the three-porosity is significantly higher than that of the surrounding rock layer. These characteristics all indicate that this layer is a permeable layer, not a dry layer. Based on the fluid identification criteria and charts for fractured-vuggy dolomitic mudstone reservoirs... Figure 12 and Figure 13 As shown, this is interpreted as oil and water in the same layer. The conclusions obtained using nuclear magnetic resonance logging are consistent with those obtained using the method described in this application.

[0159] Specific Implementation Example 2: Layers 10 and 11 of Well C3-70, such as Figure 15 As shown, the lithology is dolomitic mudstone. The reservoir resistivity characteristic value R... t The resistivity values ​​are 12 and 16 Ω·m, respectively, which are relatively low. Using the median value in the box plot, the median resistivity R0 is determined to be 30 Ω·m for both layers. The calculated reservoir space evaluation factors f are 0.4 and 0.53, respectively. The spontaneous potential shows a significant negative anomaly; the three-porosity is significantly higher than that of the surrounding rock layer. These characteristics all indicate that this layer is a permeable layer, not a dry layer. According to the fluid identification standards and charts for fractured-vuggy dolomitic mudstone reservoirs, it is interpreted as an oil-water co-containment layer. Layer 13 has a lithology of dolomitic mudstone. The reservoir resistivity characteristic value R... t The resistivity is 6 Ω·m, which is relatively low. Using the median value in the box plot, the median resistivity R0 is determined to be 8 Ω·m. The calculated reservoir space evaluation factor f = 0.75; the spontaneous potential shows a significant negative anomaly; and the three-porosity is significantly higher than that of the surrounding rock layer. These characteristics all indicate that this layer is a permeable layer, not a dry layer. Based on the fluid identification standards and charts for fractured-vuggy dolomitic mudstone reservoirs, it is interpreted as a water-bearing layer. The conclusions obtained using nuclear magnetic resonance logging are consistent with the results obtained using the method described in this application.

[0160] The specific embodiments proposed in this application take two specific wells as examples to describe the resistivity characteristics of fractured-vuggy dolomitic mudstone reservoirs. According to the method provided above, the median resistivity and reservoir space evaluation factor of the same lithology and the same hydrocarbon generation environment were calculated. The reservoir fluid properties were evaluated according to the reservoir fluid identification standards and charts of the specific implementation scheme. The evaluation conclusions are highly consistent with the oil test conclusions, indicating that this application is effective and solves the problem that conventional logging data cannot accurately identify the fluid properties of fractured-vuggy dolomitic mudstone reservoirs.

[0161] The above embodiments have described in detail the method for determining the fluid properties of dolomitic mudstone reservoirs. This application also provides embodiments corresponding to the apparatus for determining the fluid properties of dolomitic mudstone reservoirs. It should be noted that this application describes the embodiments of the apparatus from two perspectives: one based on functional modules and the other based on hardware.

[0162] Figure 16 A module diagram of a device for determining the fluid properties of dolomitic mudstone reservoirs, provided in another embodiment of this application, includes:

[0163] The detection module 11 is used to detect the resistivity of the dolomitic mudstone reservoir to be tested in order to obtain a set of resistivity data.

[0164] Anomaly determination module 12 is used to determine resistivity anomalies based on resistivity data set;

[0165] Median determination module 13 is used to determine the median resistivity based on resistivity data set and resistivity outliers;

[0166] Evaluation factor determination module 14 is used to determine the evaluation factors of the storage space based on the median resistivity and the characteristic value of resistivity.

[0167] Module 15 is used to comprehensively analyze the reservoir space evaluation factors, median resistivity, and resistivity characteristic values ​​to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

[0168] Since the embodiments of the apparatus and the embodiments of the method correspond to each other, please refer to the description of the embodiments of the method for the embodiments of the apparatus, which will not be repeated here.

[0169] Figure 17 A structural diagram of an electronic device provided in another embodiment of this application, such as... Figure 17 As shown, the electronic device includes: a memory 20 for storing computer programs;

[0170] The processor 21 is used to execute a computer program to implement the steps of the method for determining the fluid properties of dolomitic mudstone reservoirs as mentioned in the above embodiments.

[0171] The electronic devices provided in this embodiment may include, but are not limited to, smartphones, tablets, laptops, or desktop computers.

[0172] The processor 21 may include one or more processing cores, such as a quad-core processor or an octa-core processor. The processor 21 may be implemented using at least one of the following hardware forms: Digital Signal Processor (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor, also known as the Central Processing Unit (CPU), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, the processor 21 may integrate a Graphics Processing Unit (GPU), which is responsible for rendering and drawing the content to be displayed on the screen. In some embodiments, the processor 21 may also include an Artificial Intelligence (AI) processor, which is used to handle computational operations related to machine learning.

[0173] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In this embodiment, the memory 20 is used to store at least the following computer program 201, which, after being loaded and executed by the processor 21, is capable of implementing the relevant steps of the method for determining the fluid properties of dolomitic mudstone reservoirs disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, and the storage method may be temporary or permanent storage. The operating system 202 may include Windows, Unix, Linux, etc.

[0174] In some embodiments, the electronic device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0175] Those skilled in the art will understand that Figure 17 The structures shown do not constitute a limitation on electronic devices and may include more or fewer components than those shown.

[0176] The electronic device provided in this application includes a memory and a processor. When the processor executes the program stored in the memory, it can perform the aforementioned method for determining the fluid properties of dolomitic mudstone reservoirs and has the same beneficial effects.

[0177] Finally, this application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, which, when executed by a processor, implements the steps described in the above method embodiments.

[0178] It is understood that if the methods in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, 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. This computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0179] The foregoing provides a detailed description of a method, apparatus, equipment, and medium for determining the fluid properties of dolomitic mudstone reservoirs. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from the principles of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

[0180] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

Claims

1. A method for determining the fluid properties of dolomitic mudstone reservoirs, characterized in that, include: Resistivity detection was performed on the dolomitic mudstone reservoir to obtain resistivity data. Based on the resistivity data set, identify resistivity anomalies; The median resistivity is determined based on the resistivity data set and the resistivity outliers; The storage space evaluation factor is determined based on the median resistivity and resistivity characteristic value. The fluid properties of the dolomitic mudstone reservoir to be tested are determined by comprehensively analyzing the reservoir space evaluation factors, the median resistivity, and the resistivity characteristic values.

2. The method for determining the fluid properties of dolomitic mudstone reservoirs according to claim 1, characterized in that, The step of determining resistivity anomalies based on the resistivity data set includes: Determine the upper quartile and lower quartile of resistivity based on the resistivity data; The upper limit value of resistivity and the lower limit value of resistivity are determined based on the upper quartile and the lower quartile of resistivity; Anomalies in resistivity are determined based on the upper limit and lower limit of resistivity. The expression for the lower quartiles of resistivity is as follows: ； ； The expression for the upper quartile of resistivity is: ； ； The expression for the upper limit of resistivity is: ； The expression for the lower limit of resistivity is: ； Where Q1 is the lower quartile of the resistivity, L(n) is a function, P1 is the first process value, P2 is the second process value, and Q... 上 Q is the upper limit of the resistivity. 下 is the lower limit value of resistivity; n is the number of resistivity data.

3. The method for determining the fluid properties of dolomitic mudstone reservoirs according to claim 1, characterized in that, Determining the median resistivity based on the resistivity data set and the resistivity outliers includes: Determine the target resistivity data set based on the resistivity data set and the resistivity anomalies; Obtain the number of resistivity data points in the target resistivity data group, and arrange the resistivity data points in the target resistivity data group in ascending order; If the number of resistivity data points is odd, then the expression for the median resistivity is: If the number of resistivity data points is even, then the expression for the median resistivity is: ; Where R0 is the median resistivity, and n is the number of resistivity data points. For the n / 2th resistivity, For the (n / 2+1)th resistivity, It is the (n+1) / 2th resistivity.

4. The method for determining the fluid properties of dolomitic mudstone reservoirs according to claim 1, characterized in that, The step of determining the storage space evaluation factor based on the median resistivity and resistivity characteristic value includes: Obtain the resistivity characteristic value; The ratio of the resistivity characteristic value to the median resistivity is used as the evaluation factor for the storage space.

5. The method for determining the fluid properties of dolomitic mudstone reservoirs according to any one of claims 1-4, characterized in that, After determining the storage space evaluation factor based on the median resistivity and resistivity characteristic value, the method further includes: A preliminary assessment of the dolomitic mudstone reservoir to be tested is made based on the reservoir space evaluation factors. When the reservoir space evaluation factor is not less than the preset factor, the reservoir is initially determined to be a dry reservoir. When the reservoir space evaluation factor is less than the preset factor, the reservoir is initially determined to be an effective reservoir, wherein the effective reservoir includes oil layer, water layer, and oil-water co-layer.

6. The method for determining the fluid properties of dolomitic mudstone reservoirs according to claim 5, characterized in that, The comprehensive analysis of the storage space evaluation factors, the median resistivity, and the resistivity characteristic values ​​includes: Establish a resistivity-storage space evaluation factor cross plot based on the median resistivity and the storage space evaluation factor; Establish a resistivity characteristic value-storage space evaluation factor cross plot based on the resistivity characteristic value and the storage space evaluation factor; The fluid properties of the dolomitic mudstone reservoir to be tested are determined based on the cross plots of median resistivity and reservoir evaluation factors and the cross plots of resistivity eigenvalues ​​and reservoir evaluation factors.

7. The method for determining the fluid properties of dolomitic mudstone reservoirs according to claim 6, characterized in that, The determination of the fluid properties of the dolomitic mudstone reservoir to be tested based on the cross plot of median resistivity-reservoir space evaluation factor and the cross plot of resistivity characteristic value-reservoir space evaluation factor includes: When the resistivity characteristic value is less than the first characteristic value, the median resistivity is less than the first median value, and the reservoir space evaluation factor is less than the preset factor, the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be the water layer. When the resistivity characteristic value is not less than the first characteristic value and the resistivity characteristic value is less than the second characteristic value, the median resistivity is not less than the first median and the resistivity characteristic value is less than the second median, and the reservoir space evaluation factor is less than the preset factor, then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be the oil-water co-layer. If the resistivity characteristic value is not less than the second characteristic value, the median resistivity is not less than the second median value, and the reservoir space evaluation factor is less than the preset factor, then the fluid properties of the dolomitic mudstone reservoir to be tested are determined to be the oil layer.

8. A device for determining the fluid properties of dolomitic mudstone reservoirs, characterized in that, include: The detection module is used to detect the resistivity of the dolomitic mudstone reservoir under test in order to obtain resistivity data sets. An outlier determination module is used to determine outlier resistivity values ​​based on the resistivity data set. The median determination module is used to determine the median resistivity based on the resistivity data set and the resistivity outliers. The evaluation factor determination module is used to determine the storage space evaluation factor based on the median resistivity and the resistivity characteristic value. The determination module is used to comprehensively analyze the reservoir space evaluation factors, the median resistivity, and the resistivity characteristic values ​​to determine the fluid properties of the dolomitic mudstone reservoir to be tested.

9. An electronic device, characterized in that, Includes memory used to store computer programs; A processor, configured to execute the computer program to implement the steps of the method for determining the fluid properties of a dolomitic mudstone reservoir as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of a method for determining the fluid properties of a dolomitic mudstone reservoir as described in any one of claims 1 to 7.

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