A method and device for predicting low permeability reservoir physical property parameters

Abstract

The application provides a low-permeability reservoir physical property parameter prediction method and device, which comprises the following steps: classifying the low-permeability reservoir according to the capillary pressure curve characteristics of the coring well; defining a physical property quality index according to the micro-pore structure characteristics of the reservoir; establishing a physical property quality index reservoir classification standard according to the classification and the physical property quality index of the low-permeability reservoir; respectively performing regression on the porosity and the permeability according to the physical property quality index reservoir classification standard, and classifying to establish a reservoir porosity-permeability interpretation model; performing correlation analysis on the physical property quality index and the logging curve, and then performing fitting to establish a physical property quality index interpretation model; and predicting the low-permeability reservoir physical property parameters according to the established reservoir porosity-permeability interpretation model and the physical property quality index interpretation model. The application improves the accuracy of the low-permeability reservoir logging physical property interpretation model, accurately predicts the low-permeability reservoir physical property parameters, and can accurately identify and evaluate the position and range of the low-permeability reservoir favorable reservoir.

Description

Technical Field

[0001] This invention relates to the field of petroleum geological exploration and development technology, and in particular to a method and apparatus for predicting the physical properties of low-permeability reservoirs. Background Technology

[0002] This section is intended to provide background or context for embodiments of the invention as set forth in the claims. The description herein is not an admission that it is prior art simply because it is included in this section.

[0003] With the continuous expansion of oil and gas exploration scale and the increasing degree of exploration, low-permeability reservoirs have become an important target for exploration and development.

[0004] However, due to the complex pore structure, diverse mineral composition, and presence of microfractures in low-permeability reservoirs, the permeability varies significantly for the same porosity. This reduces the accuracy of conventional property interpretation models in predicting reservoir properties, thus hindering the exploration and development of such reservoirs. Reservoir properties are primarily influenced by pore structure and microfractures; therefore, effectively establishing accurate property interpretation models is a key challenge in studying the characteristics of low-permeability reservoirs.

[0005] Current well logging interpretation models for predicting reservoir properties are based on conventional reservoir calculation methods. However, for complex and variable low-permeability reservoirs, the accuracy is not high, making it difficult to accurately predict the characteristics of low-permeability reservoir properties.

[0006] Therefore, how to provide a new solution that can solve the above-mentioned technical problems is a technical challenge that urgently needs to be addressed in this field. Summary of the Invention

[0007] This invention provides a method for predicting the physical properties of low-permeability reservoirs, improving the accuracy of well logging interpretation models for low-permeability reservoirs. Accurate prediction of these properties allows for precise identification and evaluation of the location and extent of favorable reservoirs in low-permeability oil reservoirs. This enables the rapid identification of favorable targets and extents during the exploration and development of low-permeability oil reservoirs, providing a solid technical guarantee for the effective exploration and development of such reservoirs. The method includes:

[0008] Low-permeability reservoirs are classified based on the characteristics of the capillary pressure curves of the core wells;

[0009] Based on the microstructure characteristics of the reservoir, a physical property quality index is defined.

[0010] Based on the classification of low-permeability reservoirs and their physical property quality indices, a classification standard for reservoirs based on physical property quality indices is established.

[0011] Based on the reservoir classification standard of physical property quality index, porosity and permeability are regressed separately to establish reservoir porosity and permeability interpretation models.

[0012] After performing correlation analysis between the physical property quality index and the well logging curve, a fitting was performed to establish an interpretation model for the physical property quality index.

[0013] Based on the reservoir porosity-permeability interpretation model and physical property quality index interpretation model established by classification, the physical property parameters of low-permeability reservoirs are predicted.

[0014] This invention also provides a device for predicting the physical properties of low-permeability reservoirs, comprising:

[0015] The low-permeability reservoir classification module is used to classify low-permeability reservoirs based on the characteristics of the capillary pressure curves of core wells.

[0016] The physical property quality index definition module is used to define physical property quality indices based on the micropore structure characteristics of the reservoir.

[0017] The module for establishing reservoir classification standards based on physical property quality index is used to establish reservoir classification standards based on the classification of low-permeability reservoirs and physical property quality index.

[0018] The reservoir porosity and permeability interpretation model building module is used to regress porosity and permeability according to the reservoir classification standard based on physical property quality index, and classify and build reservoir porosity and permeability interpretation models.

[0019] The physical property quality index interpretation model building module is used to perform correlation analysis between the physical property quality index and the well logging curve and then fit the model to build the physical property quality index interpretation model.

[0020] The low-permeability reservoir physical property parameter prediction module is used to predict the physical property parameters of low-permeability reservoirs based on the reservoir porosity-permeability interpretation model and physical property quality index interpretation model established by classification.

[0021] This invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for predicting the physical properties of low-permeability reservoirs.

[0022] This invention also provides a computer-readable storage medium storing a computer program that performs the above-described method for predicting the physical properties of low-permeability reservoirs.

[0023] This invention provides a method and apparatus for predicting the physical properties of low-permeability reservoirs, comprising: first, classifying low-permeability reservoirs based on the characteristics of capillary pressure curves from cored wells; then, defining a physical property quality index based on the microscopic pore structure characteristics of the reservoirs; next, establishing a physical property quality index reservoir classification standard based on the classification of low-permeability reservoirs and the physical property quality index; next, regressing porosity and permeability according to the physical property quality index reservoir classification standard to establish a reservoir porosity-permeability interpretation model; then, performing correlation analysis and fitting between the physical property quality index and logging curves to establish a physical property quality index interpretation model; finally, predicting the physical properties of low-permeability reservoirs based on the established reservoir porosity-permeability interpretation model and physical property quality index interpretation model. This invention improves the accuracy of logging physical property interpretation models for low-permeability reservoirs, accurately predicts the physical properties of low-permeability reservoirs, and can precisely identify and evaluate the location and extent of favorable reservoirs in low-permeability oil reservoirs. This enables the rapid identification of favorable targets and extents in the exploration and development of low-permeability oil reservoirs, providing a solid technical guarantee for the effective exploration and development of low-permeability oil reservoirs. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0025] Figure 1 This is a schematic diagram of a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention.

[0026] Figure 2 This is a flowchart illustrating a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention.

[0027] Figure 3 This is a graph showing the relationship between calculated permeability and measured permeability in an example of a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention.

[0028] Figure 4 A schematic diagram of a computer device for running a method for predicting the physical properties of low-permeability reservoirs according to the present invention.

[0029] Figure 5 This is a schematic diagram of a device for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Here, the illustrative embodiments of the present invention and their descriptions are used to explain the present invention, but are not intended to limit the present invention.

[0031] Figure 1 This is a schematic diagram of a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention, as shown below. Figure 1 As shown, this invention provides a method for predicting the physical properties of low-permeability reservoirs, improving the accuracy of well logging interpretation models for low-permeability reservoirs. Accurate prediction of these properties allows for precise identification and evaluation of the location and extent of favorable reservoirs in low-permeability oil reservoirs. This enables the rapid identification of favorable targets and extents during the exploration and development of low-permeability oil reservoirs, providing a solid technical guarantee for the effective exploration and development of such reservoirs. The method includes:

[0032] Step 101: Classify low-permeability reservoirs based on the characteristics of the capillary pressure curves of the core wells;

[0033] Step 102: Define the physical property quality index based on the microstructure characteristics of the reservoir;

[0034] Step 103: Based on the classification of low-permeability reservoirs and their physical property quality indices, establish a physical property quality index-based reservoir classification standard;

[0035] Step 104: Based on the reservoir classification standard of physical property quality index, regress porosity and permeability respectively, and establish reservoir porosity and permeability interpretation models according to classification;

[0036] Step 105: Perform correlation analysis between the physical property quality index and the logging curve, and then fit the data to establish an interpretation model for the physical property quality index.

[0037] Step 106: Based on the reservoir porosity-permeability interpretation model and physical property quality index interpretation model established by classification, predict the physical property parameters of low-permeability reservoirs.

[0038] This invention provides a method for predicting the physical properties of low-permeability reservoirs, comprising: first, classifying low-permeability reservoirs based on the characteristics of capillary pressure curves from cored wells; then, defining a physical property quality index based on the microscopic pore structure characteristics of the reservoirs; next, establishing a physical property quality index reservoir classification standard based on the classification of low-permeability reservoirs and the physical property quality index; next, regressing porosity and permeability according to the physical property quality index reservoir classification standard to establish a reservoir porosity-permeability interpretation model; then, performing correlation analysis and fitting between the physical property quality index and logging curves to establish a physical property quality index interpretation model; finally, predicting the physical properties of low-permeability reservoirs based on the established reservoir porosity-permeability interpretation model and physical property quality index interpretation model. This invention improves the accuracy of logging physical property interpretation models for low-permeability reservoirs, accurately predicts the physical properties of low-permeability reservoirs, and can precisely identify and evaluate the location and extent of favorable reservoirs in low-permeability oil reservoirs. This enables the rapid identification of favorable targets and extents in the exploration and development of low-permeability oil reservoirs, providing a solid technical guarantee for the effective exploration and development of low-permeability oil reservoirs.

[0039] Figure 2 This is a flowchart illustrating a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention, as shown below. Figure 2 As shown, when specifically implementing the method for predicting the physical properties of low-permeability reservoirs provided in this embodiment of the invention, it may include:

[0040] Based on the characteristics of the capillary pressure curves from cored wells, low-permeability reservoirs are classified. Based on the microscopic pore structure characteristics of the reservoirs, a physical property quality index is defined. Based on the classification of low-permeability reservoirs and the physical property quality index, a reservoir classification standard based on the physical property quality index is established. Based on the reservoir classification standard based on the physical property quality index, porosity and permeability are regressed separately to establish reservoir porosity-permeability interpretation models. Correlation analysis is performed between the physical property quality index and well logging curves, followed by fitting, to establish a physical property quality index interpretation model. Based on the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model established by the classification, the physical property parameters of low-permeability reservoirs are predicted.

[0041] In a specific implementation of the method for predicting the physical properties of low-permeability reservoirs provided in this invention, in one embodiment, the aforementioned classification of low-permeability reservoirs based on the characteristics of the capillary pressure curve of the core well includes:

[0042] The characteristics of the capillary pressure curve of the core well were analyzed to obtain the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius and throat sorting coefficient of the core well.

[0043] By optimizing and classifying parameters such as permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius, and throat sorting coefficient of core wells, low-permeability reservoirs are classified according to displacement pressure, pore throat distribution concentration, pore throat radius size, and sorting quality.

[0044] In this embodiment, low-permeability reservoirs are classified based on the characteristics of the capillary pressure curves of the core wells. Specifically, this includes: analyzing the characteristics of the capillary pressure curves of the core wells to obtain the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius, and throat sorting coefficient of the core wells; optimizing parameters and comparing classifications based on the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius, and throat sorting coefficient of the core wells; and classifying low-permeability reservoirs according to the displacement pressure, the concentration of pore throat distribution, the size of the pore throat radius, and the degree of sorting.

[0045] By utilizing the characteristics of the capillary pressure curve of the core well, parameters such as permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius, and throat sorting coefficient of the core well are obtained. Through parameter optimization and classification comparison, low-permeability reservoirs are classified into Class I, II, and III according to factors such as displacement pressure, pore throat distribution concentration, pore throat radius, and sorting quality.

[0046] In this embodiment, a physical property quality index is defined based on the reservoir's micropore structure characteristics. This index is primarily related to the reservoir's micropore structure characteristics and can effectively evaluate these characteristics. Specifically, in implementing the method for predicting low-permeability reservoir physical property parameters provided by this invention, in one embodiment, the physical property quality index is defined as follows:

[0047]

[0048] Where R is the physical property quality index; K is the measured permeability of the core, in units of 10. -3 μm 2 Φ represents the measured porosity of the core sample, expressed as a percentage.

[0049] The aforementioned expression for defining the physical property quality index is for illustrative purposes only. Those skilled in the art will understand that, in practice, the above formula can be modified in a certain way and other parameters or data can be added, or other specific formulas can be provided. All such variations should fall within the protection scope of this invention.

[0050] In a specific implementation of the method for predicting the physical properties of low-permeability reservoirs provided in this invention, in one embodiment, the aforementioned establishment of a physical property quality index reservoir classification standard based on the classification of low-permeability reservoirs and physical property quality index mainly includes:

[0051] Based on the classification of low-permeability reservoirs obtained by analyzing the characteristics of capillary pressure curves, the physical property quality index corresponding to the three types of reservoirs is calculated by making full use of measured core data, thereby obtaining the physical property quality index reservoir classification standard as shown in Table 1.

[0052] Table 1

[0053] Classification Physical property quality index Ⅰ >3 Ⅱ 1-3 Ⅲ <1

[0054] In a specific implementation of the method for predicting the physical properties of low-permeability reservoirs provided in this invention, in one embodiment, the aforementioned method of regressing porosity and permeability according to the reservoir classification standard based on the physical property quality index, and establishing a reservoir porosity-permeability interpretation model, includes:

[0055] According to the reservoir classification standard based on physical property quality index, porosity and permeability are divided into three categories;

[0056] According to the corresponding categories, the porosity and permeability of the reservoir are fitted and regressed to establish reservoir porosity and permeability interpretation models.

[0057] When implementing the method for predicting the physical properties of low-permeability reservoirs provided in this embodiment of the invention, in one embodiment, reservoir porosity and permeability interpretation models are established according to the following method:

[0058] Class I:

[0059] Class II:

[0060] Class III:

[0061] Where K is the measured permeability of the core sample, in units of 10. -3 μm 2 Φ represents the measured porosity of the core sample, in %; Vsh represents the clay content, in %.

[0062] The aforementioned formula for establishing the reservoir porosity and permeability interpretation model is an example. Those skilled in the art will understand that, in practice, the above formula can be modified in a certain way and other parameters or data can be added, or other specific formulas can be provided. All such variations should fall within the protection scope of this invention.

[0063] In a specific implementation of the method for predicting the physical properties of low-permeability reservoirs provided in this invention, in one embodiment, the aforementioned correlation analysis between the physical property quality index and the well logging curve, followed by fitting, to establish an interpretation model for the physical property quality index includes:

[0064] Correlation analysis was performed between the physical property quality index and well logging curves to obtain their correlation relationships. The well logging curves included: resistivity curve, sonic transit time curve, and natural gamma ray curve. The correlations between the physical property quality index and well logging curves were as follows: a positive correlation was found between the physical property quality index and the resistivity curve; a negative correlation was found between the physical property quality index and the sonic transit time curve; and a negative correlation was found between the physical property quality index and the natural gamma ray curve.

[0065] Based on the correlation between physical property quality index and well logging curve, and by fitting physical property quality index, resistivity curve, sonic transit time curve and natural gamma curve, an interpretation model for physical property quality index is established.

[0066] In this embodiment, the physical property quality index calculated using core measurement data is correlated with each logging curve, and the following conclusions are drawn: the physical property quality parameters are positively correlated with the resistivity curve, negatively correlated with the sonic transit time curve, and negatively correlated with the natural gamma curve; based on the correlation between the physical property quality index and the logging curve, and by fitting the four parameters, an interpretation model for the physical property quality index calculated from the logging data is established.

[0067] When implementing the method for predicting the physical properties of low-permeability reservoirs provided in this embodiment of the invention, in one embodiment, a physical property quality index interpretation model is established as follows:

[0068] R = 0.7 × e 0.035×RT -0.0007×e 0.02×AC -0.631×GR 2 -1.047×GR+1

[0069] Where R is the physical property quality index; RT is the resistivity curve, in Ω·m; AC is the acoustic transit time curve, in μs / m; and GR is the natural gamma curve, in API.

[0070] The aforementioned expression for establishing the material property quality index interpretation model is for illustrative purposes only. Those skilled in the art will understand that, in practice, the above formula can be modified in a certain way and other parameters or data can be added, or other specific formulas can be provided. All such variations should fall within the protection scope of this invention.

[0071] In a specific implementation of the method for predicting the physical properties of low-permeability reservoirs provided in this invention, in one embodiment, the aforementioned reservoir porosity-permeability interpretation model and physical property quality index interpretation model established based on classification are used to predict the physical properties of low-permeability reservoirs, including:

[0072] Based on the physical property quality index interpretation model, the physical property quality of a single well is calculated. Then, in accordance with the reservoir classification standard of physical property quality index, the corresponding reservoir porosity and permeability interpretation model is selected according to the category to predict the physical property parameters of low-permeability reservoirs for the whole well.

[0073] In this embodiment, based on the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model established by classification, the physical property parameters of low-permeability reservoirs are predicted, mainly including:

[0074] Based on the physical property quality index interpretation model, the physical property quality of a single well is calculated. By referring to the reservoir classification standard of physical property quality index, the corresponding reservoir porosity and permeability interpretation model is selected according to the category. The physical property parameters of low-permeability reservoirs in the whole well are predicted and calculated. This achieves the purpose of optimizing the logging permeability calculation of the target layer and improves the accuracy of the physical property interpretation model.

[0075] This invention also provides a method for predicting the physical properties of low-permeability reservoirs, mainly including the following steps:

[0076] Step 1: Use the characteristics of the capillary pressure curve of the core well to classify low-permeability reservoirs in a direct and effective manner;

[0077] Step 2: Define the concept of physical property quality index to effectively evaluate the characteristics of reservoir pore structure;

[0078] Step 3: Based on the previous classification criteria for low-permeability reservoirs and the range of values ​​for physical property quality indices, establish a reservoir classification criterion based on physical property quality indices.

[0079] Step 4: Regress porosity and permeability according to the reservoir classification standard based on physical property quality index to obtain the classification and establish a reservoir porosity-permeability interpretation model;

[0080] Step 5: Fit the physical property quality index obtained by applying rock physics calculations with resistivity, sonic transit time and natural gamma logging curves to obtain the interpretation model of the physical property quality index calculated using logging data.

[0081] Step Six: Using the interpretation model of physical properties and the reservoir porosity and permeability interpretation model established by classification, complete the accurate prediction and calculation of physical property parameters of low-permeability reservoir blocks.

[0082] This invention also provides an example of a method for predicting the physical properties of low-permeability reservoirs, as detailed below.

[0083] The sandstone reservoir in a certain block has poor physical properties, with an overall medium porosity and low permeability level. The pore structure is complex and variable, and the relationship between porosity and permeability is poor. Therefore, accurately finding reservoirs with better physical properties is the key to finding favorable target areas.

[0084] Step 1: This area mainly develops sandstone and conglomerate reservoirs with poor physical properties and an average permeability of 90 × 10⁻⁶. -3 μm 2 Based on the capillary pressure curve characteristic data analysis of four core wells, the reservoirs are divided into three categories: I, II, and III. Category I has low displacement pressure, concentrated pore throat distribution, coarse pore throat, and moderate sorting. Category II has medium displacement pressure, relatively concentrated pore throat distribution, coarser pore throat, and poor sorting. Category III has high displacement pressure, fine pore throat, and poor sorting.

[0085] Step 2: Define and calculate the physical property quality index for the three types of reservoirs, classify them, and establish reservoir porosity and permeability interpretation models for each category.

[0086] Classification and establishment of reservoir porosity and permeability interpretation models:

[0087] Class I:

[0088] Class II:

[0089] Class III:

[0090] Where K is the measured permeability of the core sample, in units of 10. -3 μm 2 Φ represents the measured porosity of the core sample, in %; Vsh represents the clay content, in %.

[0091] Next, correlation analysis will be performed between the physical property quality index and the well logging curve, followed by fitting, to establish an interpretation model for the physical property quality index, which mainly includes:

[0092] R = 0.7 × e 0.035×RT -0.0007×e 0.02×AC -0.631×GR 2 -1.047×GR+1

[0093] Where R is the physical property quality index; RT is the resistivity curve, in Ω·m; AC is the acoustic transit time curve, in μs / m; and GR is the natural gamma curve, in API.

[0094] Step 3: Based on the reservoir porosity-permeability interpretation model and physical property quality index interpretation model established by classification, predict the physical property parameters of low-permeability reservoirs. Substitute the obtained physical property quality indices of each well into the corresponding category's physical property quality interpretation model to obtain the predicted permeability values ​​for each well. After calculation, as follows... Figure 3 In an example of a method for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention, the relationship between calculated permeability and measured permeability is shown in the graph and Table 2, which is a permeability error analysis table. The average relative error between the measured permeability data and the predicted permeability data calculated by the model is only 20%.

[0095] Table 2

[0096] Floor number Calculate penetration rate Measured permeability relative error % 20 152.13 118.22 29 47 50.18 41.83 20 12 87.01 73.92 18 23 77.85 75.50 3 36 92.92 91.45 2 48 68.03 69.25 2 34 33.68 37.17 9 25 50.09 55.29 9 53 90.67 101.09 10 46 13.19 14.92 12 31 171.73 200.35 14 15 151.71 190.15 20 37 27.49 44.15 38 30 206.49 262.81 21 45 6.04 10.12 40 16 102.89 174.64 41 41 59.94 107.68 44

[0097] As can be seen from the above examples, the embodiments of the present invention provide a method for improving the accuracy of logging property interpretation models for low-permeability reservoirs, which can accurately calculate the physical property parameters of low-permeability reservoirs and provide technical support for determining the location and extent of favorable reservoirs in low-permeability oil reservoirs.

[0098] Figure 4 A schematic diagram of a computer device for running a method for predicting the physical properties of low-permeability reservoirs according to the present invention is shown below. Figure 4 As shown, this embodiment of the invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described method for predicting the physical properties of low-permeability reservoirs.

[0099] This invention also provides a computer-readable storage medium storing a computer program that executes a method for predicting the physical properties of a low-permeability reservoir as described above.

[0100] This invention also provides a device for predicting the physical properties of low-permeability reservoirs, as described in the following embodiments. Since the principle behind this device is similar to that of a method for predicting the physical properties of low-permeability reservoirs, its implementation can be referenced in the implementation of a method for predicting the physical properties of low-permeability reservoirs; therefore, repetitions will not be repeated.

[0101] Figure 5 This is a schematic diagram of a device for predicting the physical properties of low-permeability reservoirs according to an embodiment of the present invention. Figure 5 As shown, this embodiment of the invention also provides a device for predicting the physical properties of low-permeability reservoirs, comprising:

[0102] The low-permeability reservoir classification module 501 is used to classify low-permeability reservoirs based on the characteristics of the capillary pressure curve of the core well.

[0103] The physical property quality index definition module 502 is used to define the physical property quality index based on the micropore structure characteristics of the reservoir.

[0104] The physical property quality index reservoir classification standard establishment module 503 is used to establish a physical property quality index reservoir classification standard based on the classification of low-permeability reservoirs and physical property quality indices.

[0105] The reservoir porosity and permeability interpretation model establishment module 504 is used to establish reservoir porosity and permeability interpretation models by regressing porosity and permeability according to the reservoir classification standard based on physical property quality index.

[0106] The physical property quality index interpretation model establishment module 505 is used to perform correlation analysis between the physical property quality index and the well logging curve and then fit the model to establish the physical property quality index interpretation model.

[0107] The low-permeability reservoir physical property parameter prediction module 506 is used to predict the physical property parameters of low-permeability reservoirs based on the reservoir porosity-permeability interpretation model and physical property quality index interpretation model established by classification.

[0108] In a specific implementation of the low-permeability reservoir property parameter prediction device provided in the embodiments of the present invention, in one embodiment, the aforementioned low-permeability reservoir classification module is specifically used for:

[0109] The characteristics of the capillary pressure curve of the core well were analyzed to obtain the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius and throat sorting coefficient of the core well.

[0110] By optimizing and classifying parameters such as permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius, and throat sorting coefficient of core wells, low-permeability reservoirs are classified according to displacement pressure, pore throat distribution concentration, pore throat radius size, and sorting quality.

[0111] In a specific implementation of the device for predicting the physical properties of a low-permeability reservoir provided in this embodiment of the invention, in one embodiment, the aforementioned physical property quality index definition module is specifically used to define the physical property quality index in the following manner:

[0112]

[0113] Where R is the physical property quality index; K is the measured permeability of the core, in units of 10. -3 μm 2 Φ represents the measured porosity of the core sample, expressed as a percentage.

[0114] In a specific implementation of the low-permeability reservoir property parameter prediction device provided in this embodiment of the invention, in one embodiment, the aforementioned reservoir porosity-permeability interpretation model establishment module is specifically used for:

[0115] According to the reservoir classification standard based on physical property quality index, porosity and permeability are divided into three categories;

[0116] According to the corresponding categories, the porosity and permeability of the reservoir are fitted and regressed to establish reservoir porosity and permeability interpretation models.

[0117] In a specific implementation of the device for predicting the physical properties of low-permeability reservoirs provided in the embodiments of the present invention, in one embodiment, the aforementioned reservoir porosity and permeability interpretation model establishment module is further used to establish reservoir porosity and permeability interpretation models in the following manner:

[0118] Class I:

[0119] Class II:

[0120] Class III:

[0121] Where K is the measured permeability of the core sample, in units of 10. -3 μm 2 Φ represents the measured porosity of the core sample, in %; Vsh represents the clay content, in %.

[0122] In a specific implementation of the device for predicting the physical properties of low-permeability reservoirs provided in this embodiment of the invention, in one embodiment, the aforementioned physical property quality index interpretation model establishment module is specifically used for:

[0123] Correlation analysis was performed between the physical property quality index and well logging curves to obtain their correlation relationships. The well logging curves included: resistivity curve, sonic transit time curve, and natural gamma ray curve. The correlations between the physical property quality index and well logging curves were as follows: a positive correlation was found between the physical property quality index and the resistivity curve; a negative correlation was found between the physical property quality index and the sonic transit time curve; and a negative correlation was found between the physical property quality index and the natural gamma ray curve.

[0124] Based on the correlation between physical property quality index and well logging curve, and by fitting physical property quality index, resistivity curve, sonic transit time curve and natural gamma curve, an interpretation model for physical property quality index is established.

[0125] In a specific implementation of the device for predicting the physical properties of a low-permeability reservoir provided in this embodiment of the invention, in one embodiment, the aforementioned physical property quality index interpretation model establishment module is further used to establish the physical property quality index interpretation model in the following manner:

[0126] R = 0.7 × e 0.035×RT -0.0007×e 0.02×AC -0.631×GR 2 -1.047×GR+1

[0127] Where R is the physical property quality index; RT is the resistivity curve, in Ω·m; AC is the acoustic transit time curve, in μs / m; and GR is the natural gamma curve, in API.

[0128] In a specific implementation of the low-permeability reservoir physical property parameter prediction device provided in the embodiments of the present invention, in one embodiment, the aforementioned low-permeability reservoir physical property parameter prediction module is specifically used for:

[0129] Based on the physical property quality index interpretation model, the physical property quality of a single well is calculated. Then, in accordance with the reservoir classification standard of physical property quality index, the corresponding reservoir porosity and permeability interpretation model is selected according to the category to predict the physical property parameters of low-permeability reservoirs for the whole well.

[0130] In summary, the present invention provides a method and apparatus for predicting the physical properties of low-permeability reservoirs, comprising: first, classifying low-permeability reservoirs based on the characteristics of capillary pressure curves from cored wells; then, defining a physical property quality index based on the microscopic pore structure characteristics of the reservoirs; next, establishing a physical property quality index reservoir classification standard based on the classification of low-permeability reservoirs and the physical property quality index; next, regressing porosity and permeability according to the physical property quality index reservoir classification standard to establish a reservoir porosity-permeability interpretation model; then, performing correlation analysis and fitting between the physical property quality index and well logging curves to establish a physical property quality index interpretation model; and finally, predicting the physical properties of low-permeability reservoirs based on the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model established by classification. The embodiments of the present invention improve the accuracy of logging property interpretation models for low-permeability reservoirs, accurately predict the physical property parameters of low-permeability reservoirs, and precisely identify and evaluate the location and extent of favorable reservoirs in low-permeability oil reservoirs. This enables the rapid identification of favorable targets and extents in the exploration and development of low-permeability oil reservoirs, providing a solid technical guarantee for the effective exploration and development of low-permeability oil reservoirs.

[0131] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0132] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0133] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0134] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0135] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of predicting low permeability reservoir property parameters, characterized in that, The method comprises the following steps: According to the characteristics of the capillary pressure curve of the coring well, the low-permeability reservoir is classified; According to the characteristics of the micro-pore structure of the reservoir, a physical property quality index is defined; According to the classification of the low-permeability reservoir and the physical property quality index, a physical property quality index reservoir classification standard is established; According to the physical property quality index reservoir classification standard, the porosity and the permeability are respectively regressed to establish a reservoir porosity-permeability interpretation model; The physical property quality index is correlated with the logging curve, and then the fitting is performed to establish a physical property quality index interpretation model; According to the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model established by classification, the physical property parameters of the low-permeability reservoir are predicted; The physical property quality index is defined in the following manner: Wherein, R is the physical property quality index; K is the measured core permeability, unit is 10 -3 μm 2 ; Φ is the measured core porosity, unit is %. According to the physical property quality index reservoir classification standard, the porosity and the permeability are respectively regressed to establish a reservoir porosity-permeability interpretation model, which comprises the following steps: According to the physical property quality index reservoir classification standard, the porosity and the permeability are divided into three categories; According to the corresponding categories, the porosity and the permeability of the reservoir are respectively fitted and regressed to establish a reservoir porosity-permeability interpretation model; The reservoir porosity-permeability interpretation model is established in the following manner: Class I: Class II: Class III: Wherein, K is the measured core permeability, the unit is 10 -3 μm 2 ; Φ is the measured core porosity, the unit is %; Vsh is the shale content, the unit is %.

2. The method of claim 1, wherein, According to the characteristics of the capillary pressure curve of the coring well, the low-permeability reservoir is classified, which comprises the following steps: The characteristics of the capillary pressure curve of the coring well are analyzed to obtain the permeability, porosity, drainage pressure, maximum pore throat radius, average pore throat radius and pore throat sorting coefficient of the coring well; Through parameter optimization and classification comparison of the permeability, porosity, drainage pressure, maximum pore throat radius, average pore throat radius and pore throat sorting coefficient of the coring well, the low-permeability reservoir is classified according to the high and low drainage pressure, the concentration degree of pore throat distribution, the size of pore throat radius and the good and bad sorting degree.

3. The method of claim 1, wherein, The physical property quality index is correlated with the logging curve, and then the fitting is performed to establish a physical property quality index interpretation model, which comprises the following steps: The physical property quality index is correlated with the logging curve to obtain the correlation between the physical property quality index and the logging curve; wherein, the logging curve comprises the resistivity curve, the acoustic time difference curve and the natural gamma ray curve; the correlation between the physical property quality index and the logging curve comprises that the physical property quality index and the resistivity curve have a positive correlation, the physical property quality index and the acoustic time difference curve have a negative correlation, and the physical property quality index and the natural gamma ray curve have a negative correlation, According to the correlation between the physical property quality index and the logging curve, the physical property quality index, the resistivity curve, the acoustic time difference curve and the natural gamma ray curve are fitted to establish a physical property quality index interpretation model.

4. The method of claim 3, wherein, The physical property quality index interpretation model is established in the following manner: R = 0.7 x e 0.035×RT - 0.0007 x e 0.02×AC - 0.631 x GR 2 - 1.047 x GR + 1 wherein, R is the physical property quality index; RT is the resistivity curve with the unit of Ω·m; AC is the acoustic time difference curve with the unit of μs / m; and GR is the natural gamma ray curve with the unit of API.

5. The method of claim 1, wherein, According to the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model established by classification, the physical property parameters of the low-permeability reservoir are predicted, which comprises the following steps: According to the physical property quality index interpretation model, the physical property quality of a single well is calculated, and the reservoir porosity-permeability interpretation model corresponding to the category is selected according to the physical property quality index reservoir classification standard to predict the physical property parameters of the low-permeability reservoir of the whole well.

6. A device for predicting low permeability reservoir property parameters, characterized in that, ​ The low-permeability reservoir classification module is configured to classify low-permeability reservoirs according to the capillary pressure curve characteristics of coring wells. The physical property quality index definition module is configured to define the physical property quality index according to the micro-pore structure characteristics of the reservoir. The physical property quality index reservoir classification standard establishment module is configured to establish the physical property quality index reservoir classification standard according to the classification of the low-permeability reservoir and the physical property quality index. The reservoir porosity-permeability interpretation model establishment module is configured to regress the porosity and the permeability respectively according to the physical property quality index reservoir classification standard, and to classify and establish the reservoir porosity-permeability interpretation model. The physical property quality index interpretation model establishment module is configured to perform correlation analysis on the physical property quality index and the logging curve, and then to perform fitting to establish the physical property quality index interpretation model. The low-permeability reservoir physical property parameter prediction module is configured to predict the physical property parameters of the low-permeability reservoir according to the reservoir porosity-permeability interpretation model and the physical property quality index interpretation model classified and established. The physical property quality index definition module is specifically configured to define the physical property quality index in the following manner: Wherein, R is the physical property quality index; K is the measured core permeability, unit is 10 -3 μm 2 ; Φ is the measured core porosity, unit is %. The reservoir porosity-permeability interpretation model establishment module is specifically configured to: divide the porosity and the permeability into three categories according to the physical property quality index reservoir classification standard; perform fitting calculation regression on the porosity and the permeability of the reservoir according to the corresponding categories, and classify and establish the reservoir porosity-permeability interpretation model. The reservoir porosity-permeability interpretation model establishment module is also configured to classify and establish the reservoir porosity-permeability interpretation model in the following manner: Class I: Class II: Class III: Wherein, K is the measured core permeability, the unit is 10 -3 μm 2 ; Φ is the measured core porosity, the unit is %; Vsh is the shale content, the unit is %.

7. The apparatus of claim 6, wherein, The low-permeability reservoir classification module is specifically configured to: analyze the capillary pressure curve characteristics of coring wells to obtain the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius and pore throat sorting coefficient of the coring wells; classify the low-permeability reservoirs according to the displacement pressure, the concentration degree of pore throat distribution, the size of pore throat radius and the sorting degree by performing parameter optimization and classification comparison on the permeability, porosity, displacement pressure, maximum pore throat radius, average pore throat radius and pore throat sorting coefficient of the coring wells.

8. The apparatus of claim 6, wherein, The physical property quality index interpretation model establishment module is specifically configured to: perform correlation analysis on the physical property quality index and the logging curve to obtain the correlation relationship between the physical property quality index and the logging curve; wherein the logging curve includes the resistivity curve, the acoustic time difference curve and the natural gamma ray curve; the correlation relationship between the physical property quality index and the logging curve includes that the physical property quality index and the resistivity curve are positively correlated, the physical property quality index and the acoustic time difference curve are negatively correlated, and the physical property quality index and the natural gamma ray curve are negatively correlated, perform fitting on the physical property quality index, the resistivity curve, the acoustic time difference curve and the natural gamma ray curve according to the correlation relationship between the physical property quality index and the logging curve to establish the physical property quality index interpretation model.

9. The apparatus of claim 8, wherein, The physical property quality index interpretation model establishment module is also configured to establish the physical property quality index interpretation model in the following manner: R = 0.7 x e 0.035×RT - 0.0007 x e 0.02×AC - 0.631 x GR 2 - 1.047 x GR + 1 wherein R is the physical property quality index; RT is the resistivity curve with the unit of Ω·m; AC is the acoustic time difference curve with the unit of μs / m; and GR is the natural gamma ray curve with the unit of API.

10. The apparatus of claim 6, wherein, The low-permeability reservoir physical property parameter prediction module is specifically configured to: According to the physical property quality index interpretation model, the physical property quality of single well is calculated, and the low-permeability reservoir physical property parameters of the whole well are predicted by comparing with the reservoir classification standard of the physical property quality index and selecting the corresponding reservoir porosity and permeability interpretation model according to the category.

11. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the method of any one of claims 1-5 when executing the computer program.

12. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the method of any one of claims 1-5.

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