Method and system for analyzing main control factors influencing tight sandstone fracture development

Abstract

The invention discloses a method and system for analyzing main control factors affecting tight sandstone fracture development, and the method comprises the steps: determining fracture factors affecting fracture development based on a geological mode of tight sandstone gas reservoir fracture development; determining a plurality of fracture development indexes according to the imaging logging data, the core data and the field outcrop data of the target area; and quantitatively analyzing the correlation between each fracture factor and a plurality of fracture development indexes to screen main control factors influencing the fracture development of the tight sandstone. According to the method, the main control factors of the crack can be efficiently and accurately represented.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas reservoir development, and particularly to a method and system for analyzing the main controlling factors affecting the development of fractures in tight sandstone. Background Art

[0002] Tight oil and gas reservoirs are characterized by low porosity, low permeability, etc. According to existing drilling data and development production experience, fractures are the key factors restricting the development effect of tight oil and gas reservoirs. For fracture prediction, a great deal of work has been done in geophysical prediction. However, due to the huge difference between the scale of fractures and the resolution of seismic data, the effect of fracture prediction is very limited.

[0003] In the prior art, from the perspective of the mechanism of fracture generation, it is considered that the degree of fracture development is mainly determined by two aspects: external factors controlled by tectonic stress and deformation, and internal factors controlled by rock physics. However, existing research mainly focuses on qualitative analysis and single-factor analysis. There is a lack of quantitative analysis of the influence degree and comprehensive research on multiple factors that determine the main controlling factors of fracture development.

[0004] Therefore, the prior art needs to provide a multi-factor quantitative comprehensive analysis scheme applicable to tight sandstone to optimize the main controlling factors of fracture development. Summary of the Invention

[0005] The purpose of the present invention is to provide a multi-factor quantitative comprehensive analysis scheme applicable to tight sandstone to optimize the main controlling factors of fracture development.

[0006] To solve the above technical problems, an embodiment of the present invention provides a method for analyzing the main controlling factors affecting the development of fractures in tight sandstone, including: determining fracture factors affecting fracture development based on the geological model of fracture development in tight sandstone gas reservoirs; determining a plurality of fracture development indicators according to the imaging logging data, core data, and outcrop data of the target area; screening the main controlling factors affecting the development of fractures in tight sandstone by quantitatively analyzing the correlation between each fracture factor and the plurality of fracture development indicators.

[0007] Preferably, the fracture factors include but are not limited to the distance from the fault, the aspect ratio of the fault, the throw of the fault, the fault dip angle, the height of the fold, the width of the fold, the distance to the core, the quartz content, the quartz structure, the feldspar content, the coal content, the porosity, the permeability, and the shale content; the plurality of fracture development indicators include but are not limited to the fracture density, the fracture dip angle, the high-angle fracture density, the fracture aperture, the fracture porosity, and the fracture permeability.

[0008] Preferably, in the step of screening the main controlling factors affecting the fracture development of tight sandstone by quantitatively analyzing the correlation between each fracture factor and the multiple fracture development indicators, the following steps are included: calculating the correlation coefficient between each fracture factor and each fracture development indicator according to the data of each fracture factor and the data of each fracture development indicator; sorting the correlation coefficients under the same fracture factor and screening out the fracture factors with the correlation coefficient greater than the preset correlation coefficient threshold to obtain one or more main controlling factors of fracture development affecting each fracture development indicator.

[0009] Preferably, the preset correlation coefficient threshold is greater than 0.5.

[0010] Preferably, in the step of sorting the correlation coefficients under the same fracture factor and screening out the fracture factors with the correlation coefficient greater than the preset correlation coefficient threshold to obtain one or more main controlling factors of fracture development affecting each fracture development indicator, the following steps are included: using the preset correlation coefficient and correlation level relationship model to convert the correlation coefficients under different fracture development indicators into a heat map of the correlation between the fracture factor and the fracture development indicator, so as to use the heat map of the correlation between the fracture factor and the fracture development indicator to screen the main controlling factors of fracture development corresponding to each fracture development indicator.

[0011] Preferably, the correlation coefficient between each fracture factor and each fracture development indicator is calculated by the Pearson correlation coefficient calculation method or the Spearman rank correlation coefficient calculation method for quantitative analysis of the correlation.

[0012] Preferably, if the data of the two variables to be calculated for correlation obey the normal distribution, the Pearson correlation coefficient calculation method is used to calculate the corresponding correlation coefficient, otherwise the Spearman rank correlation coefficient calculation method is used.

[0013] In addition, an embodiment of the present invention provides a computer-readable storage medium, which includes a series of instructions for executing the method steps for analyzing the main controlling factors affecting the fracture development of tight sandstone as described above.

[0014] On the other hand, an embodiment of the present invention further provides a system for analyzing the main controlling factors affecting the fracture development of tight sandstone, including: a fracture factor generation module configured to determine the fracture factors affecting the fracture development based on the geological pattern of the fracture development in the tight sandstone gas reservoir; a fracture development indicator generation module configured to determine multiple fracture development indicators according to the imaging logging data, core data and outcrop data of the target area; and a main controlling factor analysis module configured to screen the main controlling factors affecting the fracture development of tight sandstone by quantitatively analyzing the correlation between each fracture factor and the multiple fracture development indicators.

[0015] Preferably, the fracture factors include, but are not limited to, the distance from the fault, the aspect ratio of the fault, the throw of the fault, the fault dip angle, the height of the fold, the width of the fold, the distance to the core, the quartz content, the quartz structure, the feldspar content, the coal quality content, the porosity, the permeability, and the shale content; the multiple fracture development indicators include, but are not limited to, the fracture density, the fracture dip angle, the high-angle fracture density, the fracture aperture, the fracture porosity, and the fracture permeability.

[0016] Compared with the prior art, one or more embodiments of the above solution may have the following advantages or beneficial effects:

[0017] The present invention provides a method and a system for analyzing the main controlling factors affecting the fracture development in tight sandstone. The method and the system include: 1) selecting the external factors and internal factors for fracture development based on the geological model of fracture development in the tight sandstone gas reservoir; 2) using the imaging logging data, core data, and field outcrop data of the drilled wells in the target area to statistically analyze the data related to fracture development; 3) using the Pearson correlation coefficient method or the Spearman rank correlation coefficient method to statistically analyze the correlation between different parameters and the fracture development data; 4) ranking the correlations according to the calculation results of the Pearson correlation coefficient method or the Spearman rank correlation coefficient method; 5) retaining the parameters with high correlations and eliminating the parameters with low correlations; 6) finally obtaining the main controlling factors for fracture development in the tight sandstone gas reservoir. The present invention can efficiently and accurately characterize the main controlling factors of fractures, providing a very reliable basis for work such as finding fracture enrichment areas, oilfield production and development, and well location deployment.

[0018] Specifically, the fracture factors determined by the present invention are achieved based on the characterization results of the fracture system caused by faults and the characterization results of the fracture system caused by folds, changing the previous phenomenon of only considering the fractures caused by faults when characterizing fractures and ignoring the fractures caused by folds; moreover, the present invention accurately characterizes the main controlling factors of fractures, providing a very reliable basis for work such as finding fracture enrichment areas, oilfield production and development, and well location deployment. Thus, the expected effect of the present invention is to realize intelligent, accurate, and efficient prediction of the main controlling factors of fracture control under the constraint of the geological model, which can promote the efficient development of tight gas reservoirs.

[0019] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained by the structures specifically pointed out in the specification, the claims, and the drawings. Description of the Drawings

[0020] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention. In the accompanying drawings:

[0021] Figure 1 It is a schematic diagram of the steps of the method for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiment of the present application.

[0022] Figure 2 It is a schematic diagram of the specific process of the method for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiment of the present application.

[0023] Figure 3 It is an example diagram of the geological model of fracture development in the tight sandstone gas reservoir in the method for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiment of the present application.

[0024] Figure 4 It is an example diagram of the statistical chart of the correlation between the fracture development index calculated based on the Pearson correlation coefficient and the fracture factor in the method for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiment of the present application.

[0025] Figure 5 It is a block diagram of the modules of the system for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiment of the present application. Detailed implementation manners

[0026] The following will describe in detail the implementation manners of the present invention in combination with the accompanying drawings and embodiments, so as to fully understand how the present invention uses technical means to solve technical problems and the implementation process of achieving technical effects and implement accordingly. It should be noted that as long as there is no conflict, the various embodiments in the present invention and the various features in each embodiment can be combined with each other, and the formed technical solutions are all within the protection scope of the present invention.

[0027] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0028] The terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms "a" and "an" used herein are also intended to include the plural. It should also be understood that the terms "including" and / or "comprising" used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, and do not exclude the presence or addition of one or more other features, integers, steps, operations, units, components, and / or their combinations.

[0029] To solve the technical problems in the above-mentioned background art, an embodiment of the present application proposes a method and system for analyzing the main controlling factors affecting the development of fractures in tight sandstone. Based on the geological model of fracture development, the method and system optimize the main controlling factors of fracture development through correlation analysis, so as to characterize the main controlling factors of fracture development in tight gas reservoirs.

[0030] Example 1

[0031] Figure 1 It is a schematic diagram of the steps of the method for analyzing the main controlling factors affecting the development of fractures in tight sandstone according to an embodiment of the present application. Figure 2 It is a schematic diagram of the specific process of the method for analyzing the main controlling factors affecting the development of fractures in tight sandstone according to an embodiment of the present application. The following combines Figure 1 and Figure 2 , and describes the specific step process of the method for analyzing the main controlling factors affecting the development of fractures in tight sandstone (also called "fracture development main controlling factor analysis method") described in the embodiments of the present invention.

[0032] Step S110 determines fracture factors affecting fracture development based on the geological model of fracture development in tight sandstone gas reservoirs.

[0033] For tight sandstone gas reservoirs, in different regions, fracture development has different geological models. According to the fracture development pattern in the area where the drilled wells are located in the target area to be studied (see Figure 3 ), combined with the tectonic background of the target area, the influence of faults and folds on fractures is the most critical. In step S110, according to the actual situation of the area to be studied, it is clear that the development of tight sandstone fractures is mainly controlled by external factors such as tectonic stress and deformation, and internal factors controlled by rock physics are secondary. The geological model of fracture development in tight sandstone gas reservoirs is mainly affected by large-scale faults and folds (as shown in Figure 3 ). Under the constraint of the geological model, fracture factors related to fracture genesis are characterized. Therefore, in the embodiments of the present invention, the fracture factors include not only fault characteristic parameters but also fold characteristic parameters.

[0034] In one embodiment, the fracture factors include but are not limited to: distance from the fault, width-to-height ratio of the fault, fault throw (i.e., displacement), fault dip angle, height of the fold, width of the fold, distance to the (fold) core, quartz content, quartz structure (i.e., grain size), feldspar content, coal content, porosity, permeability, and shale content.

[0035] Step S120 determines multiple fracture development indicators according to the imaging logging data, core data, and outcrop data of the target area to be evaluated.

[0036] In step S120, according to the imaging logging data, core fracture data, and outcrop data of the drilled wells in the target area, the fracture development index of the current area is statistically calculated. In an embodiment of the present invention, the fracture development index is an index that can reflect the fracture development situation. In an embodiment of the present invention, the fracture development index includes, but is not limited to: fracture density, fracture dip angle, high-angle fracture density (for example, the fracture density of fractures greater than a preset angle, where the preset angle is preferably 30°), fracture aperture, fracture porosity, and fracture permeability.

[0037] Specifically, the fracture data from different sources in the target area to be evaluated are sorted, summarized, and statistically analyzed to obtain a plurality of fracture development indexes. The plurality of fracture development indexes are constructed as the actual data of each fracture development index of different wells in the horizontal direction and the actual data of each fracture development index of different horizons in the vertical direction.

[0038] Next, in step S130, the main controlling factors affecting the fracture development of tight sandstone are screened by quantitatively analyzing the correlation between each fracture factor and the plurality of fracture development indexes obtained in step S120.

[0039] In step S130, first, according to the actual data of each fracture factor and the actual data of each fracture development index, the correlation coefficient between each fracture factor and each fracture development index is calculated.

[0040] In one embodiment, the correlation coefficient between each fracture factor and each fracture development index is calculated by the Pearson correlation coefficient calculation method or the Spearman rank correlation coefficient calculation method to quantitatively analyze the correlation.

[0041] In an embodiment of the present invention, which method is selected to calculate the correlation between different variables is related to whether the variables are linearly correlated. If the data of the two variables to be calculated for correlation follow a normal distribution, the Pearson correlation coefficient calculation method is used to calculate the corresponding correlation coefficient; otherwise, the Spearman rank correlation coefficient calculation method is used.

[0042] Figure 4 This is an example diagram of the statistical chart of the correlation between the fracture development index calculated based on the Pearson correlation coefficient and the fracture factor in the method for analyzing the main controlling factors affecting the fracture development of tight sandstone in the embodiments of the present application. Figure 4 It shows the calculation results of the correlation coefficient between the fracture density and each fracture factor calculated by the Pearson correlation coefficient method, and the calculation results of the correlation coefficient between the high-angle fracture density and each fracture factor.

[0043] In one embodiment, the Pearson correlation coefficient calculation (Pearson correlation coefficient calculation method) is simple and can describe the linear relationship between two variables. The greater the covariance between two variables, the closer the trends presented by their values within a range of data points. This method has relatively high requirements for data. The data is usually assumed to come from a normal distribution, and the gap between experimental data should not be too large. The Pearson correlation coefficient is greatly affected by outliers. The formula for calculating the Pearson correlation coefficient is as follows:

[0044]

[0045] In Equation (1), ρ1(X,Y) represents the Pearson correlation coefficient between the Xth crack factor variable and the Yth crack development index variable, σ X and σ Y represent the standard deviations of variable X and variable Y respectively, μ X and μ Y represent the means of variable X and variable Y respectively, E[(X - μ X )(Y - μ Y )] represents the covariance between variable X and variable Y, n1 represents the total number of data of variable X, X i represents the ith data in variable X, n2 represents the total number of data of variable Y, and Y j represents the jth data in variable Y.

[0046] In one embodiment, the Spearman rank correlation coefficient, also known as the rank correlation coefficient. The Spearman rank correlation coefficient calculation method is mainly used to describe the degree and direction of association between two variables when there are ranked variables or when the variable distribution characteristics cannot be described by the mean and standard deviation. The range of the Spearman rank correlation coefficient is from -1 to 1. A negative value indicates negative correlation, and 0 indicates no correlation. Its expression is:

[0047]

[0048] In Equation (2), ρ2(X,Y) represents the Spearman rank correlation coefficient between the Xth crack factor variable and the Yth crack development index variable; N represents the paired sample size of variable X and variable Y; i represents the serial number of the paired samples; d i represents the difference in ranks of the ith pair of paired sample variables, that is, the difference in the positions (ranks) of the paired variables after sorting the two variables respectively.

[0049] After calculating the correlation coefficients between each fracture factor variable and each fracture development index variable, step S130 also sorts the correlation coefficients under the same fracture factor and filters out the fracture factors with correlation coefficients greater than the preset correlation coefficient threshold, so as to obtain one or more main controlling factors of fracture development affecting each fracture development index.

[0050] Since it is considered that the geological pattern of fracture development in the target area is mainly controlled by external factors such as tectonic deformation and stress, fracture factors with a correlation coefficient higher than 0.5 are selected. In one embodiment, the preset correlation coefficient threshold is greater than 0.5.

[0051] Through the calculation and analysis of the correlation coefficients of the above two methods, fracture development index parameters with relatively strong correlation with fracture development are screened out. Specifically, the correlation coefficients calculated by the Pearson correlation coefficient method or the Spearman rank correlation coefficient method are sorted, the parameters with higher correlation coefficients are retained, and the parameters with lower correlation coefficients are excluded. In one embodiment, the parameters with the absolute value of the Pearson correlation coefficient or the Spearman rank correlation coefficient less than 0.5 are excluded, the parameters with the absolute value of the calculated correlation coefficient greater than 0.5 are retained, and the fracture development indexes corresponding to the calculated and excluded coefficients are retained to obtain the final main controlling factors of fractures in tight sandstone gas reservoirs.

[0052] In one embodiment, the embodiment of the present invention will use a pre-constructed relationship model between correlation coefficients and correlation levels to convert the correlation coefficients under different fracture development indexes into a heat map of the correlation between fracture factors and fracture development indexes, so as to screen out the main controlling factors of fracture development corresponding to each fracture development index by using the converted heat map of the correlation between fracture factors and fracture development indexes.

[0053] Specifically, the embodiment of the present invention will divide a series of obtained correlation coefficients into multiple correlation levels according to the numerical size of the absolute value of the coefficient, determine the coefficients with an absolute value of the correlation coefficient of 0.8 - 1.0 as extremely strongly correlated, determine the coefficients with an absolute value of the correlation coefficient of 0.6 - 0.8 as strongly correlated, determine the coefficients with an absolute value of the correlation coefficient of 0.4 - 0.6 as moderately correlated, determine the coefficients with an absolute value of the correlation coefficient of 0.2 - 0.4 as weakly correlated, and determine the coefficients with an absolute value of the correlation coefficient of 0 - 0.2 as extremely weakly or uncorrelated. Among them, the correlation level division table is shown in Table 1:

[0054] Table 1 Correlation level division table

[0055] Variable correlation level Absolute value of correlation coefficient Very strong correlation 0.8-1.0 Strong correlation 0.6-0.8 Medium correlation 0.4-0.6 Weak correlation 0.2-0.4 Very weak or no correlation 0.0-0.2

[0056] In this way, after converting the correlation coefficients between different fracture development indicators and each fracture factor into a heat map of the correlation between the fracture factor and the fracture development indicator, the embodiments of the present invention can use the converted heat map of the correlation between the fracture factor and the fracture development indicator to quickly screen out one or more fracture factors corresponding to each fracture development indicator, that is, the main controlling factors of fracture development.

[0057] Example 2

[0058] Based on the above method for analyzing the main controlling factors of fracture development, the embodiments of the present invention also provide a computer-readable storage medium, on which a computer program is stored, and the computer program is executed to run a method for analyzing the main controlling factors affecting the fracture development of tight sandstone. The computer program can run computer instructions, and the computer instructions include computer program code, and the computer program code can be in the form of source code, object code, executable file or some intermediate form, etc.

[0059] The computer-readable storage medium may include: any entity or device capable of carrying computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electrical carrier signal, telecommunication signal, and software distribution medium, etc.

[0060] It should be noted that the content included in the computer-readable storage medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, it is appropriately increased or decreased according to the requirements of legislation and patent practice. For example, in some jurisdictions, it is appropriately increased or decreased according to the requirements of legislation and patent practice. For example, in some jurisdictions according to patent practice, the computer-readable storage medium does not include electrical carrier signals and telecommunication signals.

[0061] Example 3

[0062] Based on the above method for analyzing the main controlling factors of fracture development, the embodiments of the present invention also provide a system for analyzing the main controlling factors affecting the fracture development of tight sandstone (also referred to as the "main controlling factor analysis system for fracture development"). The main controlling factor analysis system for fracture development is used to implement the above method for analyzing the main controlling factors of fracture development.

[0063] Figure 5 It is a block diagram of the modules of the system for analyzing the main controlling factors affecting the fracture development of tight sandstone according to the embodiments of the present application. As Figure 5 shown, the main controlling factor analysis system for fracture development described in the embodiments of the present invention includes: a fracture factor generation module 51, a fracture development indicator generation module 52, and a main controlling factor analysis module 53.

[0064] Specifically, the fracture factor generation module 51 is implemented according to the method described in step S110 above, and is configured to determine fracture factors affecting fracture development based on the geological model of fracture development in a tight sandstone gas reservoir; the fracture development index generation module 52 is implemented according to the method described in step S120 above, and is configured to determine multiple fracture development indexes according to the imaging logging data, core data and outcrop data of the target area; the main control factor analysis module 53 is implemented according to the method described in step S130 above, and is configured to screen the main control factors affecting the fracture development in tight sandstone by quantitatively analyzing the correlation between each fracture factor and multiple fracture development indexes respectively.

[0065] In one embodiment, the fracture factors include but are not limited to: distance from the fault, aspect ratio of the fault, throw of the fault, fault dip angle, height of the fold, width of the fold, distance to the core, quartz content, quartz structure, feldspar content, coal content, porosity, permeability and shale content.

[0066] In one embodiment, the multiple fracture development indexes include but are not limited to fracture density, fracture dip angle, high-angle fracture density, fracture aperture, fracture porosity and fracture permeability.

[0067] The present invention discloses a method and a system for analyzing the main control factors affecting the fracture development in tight sandstone. The method and the system include: 1) Selecting external factors and internal factors for fracture development based on the geological model of fracture development in a tight sandstone gas reservoir; 2) Using the imaging logging data, core data and outcrop data of the drilled wells in the target area to statistically analyze the data related to fracture development; 3) Using the Pearson correlation coefficient method or the Spearman rank correlation coefficient method to statistically analyze the correlation between different parameters and the fracture development data; 4) Ranking the correlations according to the calculation results of the Pearson correlation coefficient method or the Spearman rank correlation coefficient method; 5) Retaining the parameters with high correlations and eliminating the parameters with low correlations; 6) Finally obtaining the main control factors for the fracture development in the tight sandstone gas reservoir. The present invention can efficiently and accurately characterize the main control factors of fractures, providing a very reliable basis for work such as finding fracture enrichment areas, oilfield production and development, and well location deployment.

[0068] Specifically, the fracture factor determined in the present invention is achieved based on the characterization results of the fault-originated fracture system and the fold-originated fracture system, changing the previous phenomenon of only considering the faults-originated fractures when characterizing fractures while ignoring the fold-originated fractures. Moreover, the present invention accurately characterizes the main controlling factors of fractures, providing a very reliable basis for work such as finding fracture enrichment areas, oilfield production and development, and well location deployment. Thus, the expected effect of the present invention is to realize intelligent, accurate and efficient prediction of the main controlling factors of fracture control under the constraint of the geological model, which can promote the efficient development of tight gas reservoirs.

[0069] As described above, only the preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered by the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

[0070] In the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0071] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] It should be understood that the embodiments disclosed in the present invention are not limited to the specific structures, processing steps or materials disclosed herein, but should extend to equivalent alternatives of these features understood by those of ordinary skill in the relevant art. It should also be understood that the terms used herein are only for the purpose of describing specific embodiments and do not mean to limit.

[0073] As used herein, the phrase "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrase "one embodiment" or "an embodiment" throughout the specification are not necessarily all referring to the same embodiment.

[0074] Although the embodiments disclosed in the present invention are as described above, the content described is only an embodiment adopted for the convenience of understanding the present invention and is not intended to limit the present invention. Any person skilled in the art within the technical field to which the present invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed by the present invention. However, the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A method for analyzing the main controlling factors affecting the development of fractures in tight sandstone, characterized in that Including: Based on the geological model of fracture development in tight sandstone gas reservoirs, determining fracture factors that affect fracture development; Determining multiple fracture development indicators according to the imaging logging data, core data, and outcrop data of the target area; Screening the main controlling factors affecting the fracture development of tight sandstone by quantitatively analyzing the correlation between each fracture factor and the multiple fracture development indicators.

2. The method according to claim 1, wherein The fracture factors include, but are not limited to, the distance from the fault, the aspect ratio of the fault, the throw of the fault, the fault dip angle, the height of the fold, the width of the fold, the distance to the core, the quartz content, the quartz structure, the feldspar content, the coal content, the porosity, the permeability, and the shale content; The multiple fracture development indicators include, but are not limited to, fracture density, fracture dip angle, high-angle fracture density, fracture aperture, fracture porosity, and fracture permeability.

3. The method according to claim 2, characterized in that In the step of screening the main controlling factors affecting the fracture development of tight sandstone by quantitatively analyzing the correlation between each fracture factor and the multiple fracture development indicators, it includes: According to the data of each fracture factor and the data of each fracture development indicator, calculating the correlation coefficient between each fracture factor and each fracture development indicator; Sorting the correlation coefficients under the same fracture factor and screening out the fracture factors with correlation coefficients greater than the preset correlation coefficient threshold to obtain one or more main controlling factors of fracture development affecting each fracture development indicator.

4. The method according to claim 3, characterized in that, The preset correlation coefficient threshold is greater than 0.

5.

5. The method according to claim 3 or 4, characterized in that, In the step of sorting the correlation coefficients under the same fracture factor and screening out the fracture factors with correlation coefficients greater than the preset correlation coefficient threshold to obtain one or more main controlling factors of fracture development affecting each fracture development indicator, it includes: Using the preset relationship model between the correlation coefficient and the correlation level, converting the correlation coefficients under different fracture development indicators into a heat map of the correlation between the fracture factor and the fracture development indicator, so as to use the heat map of the correlation between the fracture factor and the fracture development indicator to screen the main controlling factors of fracture development corresponding to each fracture development indicator.

6. The method according to any one of claims 1 to 5, characterized in that, Calculating the correlation coefficient between each fracture factor and each fracture development indicator by the Pearson correlation coefficient calculation method or the Spearman rank correlation coefficient calculation method for quantitative analysis of the correlation.

7. The method according to claim 6, wherein If the data of the two variables to be calculated for correlation obey the normal distribution, the Pearson correlation coefficient calculation method is used to calculate the corresponding correlation coefficient, otherwise the Spearman rank correlation coefficient calculation method is used.

8. A computer-readable storage medium, characterized in that, It includes a series of instructions for executing the method steps described in any one of claims 1 to 7.

9. A system for analyzing the main controlling factors affecting the development of fractures in tight sandstone, characterized in that, Including: A fracture factor generation module configured to determine fracture factors that affect fracture development based on the geological model of fracture development in tight sandstone gas reservoirs; A fracture development indicator generation module configured to determine multiple fracture development indicators according to the imaging logging data, core data, and outcrop data of the target area; A main controlling factor analysis module configured to screen the main controlling factors affecting the fracture development of tight sandstone by quantitatively analyzing the correlation between each fracture factor and the multiple fracture development indicators.

10. The system according to claim 9, characterized in that, The crack factors include, but are not limited to, the distance from the fault, the aspect ratio of the fault, the throw of the fault, the fault dip angle, the height of the fold, the width of the fold, the distance to the core, the quartz content, the quartz structure, the feldspar content, the coal quality content, the porosity, the permeability, and the shale content; The multiple crack development indicators include, but are not limited to, the crack density, the crack dip angle, the high-angle crack density, the crack aperture, the crack porosity, and the crack permeability.

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