Five-property evaluation method and device for tight sandstone gas reservoir

Abstract

The invention discloses a tight sandstone gas reservoir five-property evaluation method and device, and relates to the technical field of unconventional tight oil-gas exploration and development, and the method comprises the steps: obtaining the detailed information of the exploration and development difficulty of a tight sandstone gas reservoir, and obtaining a supplement scheme of a conventional logging means; through integrated matching treatment of unconventional means, a tight sandstone gas reservoir logging technology series is obtained; obtaining the basis of logging five-property evaluation; performing correlation analysis on various parameters through a principal component analysis algorithm and automatic distribution of evaluation index weights, and establishing a compact sandstone gas reservoir quality model; through application of a comprehensive quality calculation method and combination of gas testing data, a tight sandstone gas reservoir evaluation standard based on reservoir comprehensive quality is obtained, and reservoir division is realized. By means of the five-property evaluation method for the tight sandstone gas reservoir, the heterogeneous reservoir can be selected from the middle and the middle, and support is provided for high and stable yield of a horizontal well.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of unconventional tight oil and gas exploration and development, and particularly relates to a method and device for evaluating five properties of a tight sandstone gas reservoir. BACKGROUND

[0002] Compared with conventional clastic rock reservoirs, the evaluation of tight sandstone gas reservoirs faces many outstanding problems. Due to the tight reservoir lithology and small reservoir space, the effective geological information of the reaction pore space and fluid properties is greatly reduced. In addition, the tight sandstone reservoirs have undergone complex physical and chemical changes during diagenetic evolution, resulting in complex reservoir space and serious reservoir heterogeneity. Therefore, the logging parameter solution model established by using the conventional geostatistical method cannot adapt to the comprehensive evaluation of the tight sandstone reservoir, and the application effect is poor. To solve this problem, it is necessary to carry out research on the comprehensive evaluation method of the tight sandstone gas reservoir, establish a reservoir quantitative characterization method based on more abundant logging parameters, and realize the comprehensive evaluation of the reservoir from multiple angles to provide a basis for further exploration and development of oil and gas reservoirs.

[0003] The development of tight gas reservoirs basically adopts the way of horizontal well scale fracturing, and the development of fracturing scheme needs rich reservoir evaluation data to support. The traditional reservoir "three property" evaluation method cannot meet the needs of fracturing reconstruction, and the "lithology, physical property, gas content, brittleness, rock mechanics" five property evaluation of the reservoir has become the industry consensus. In the current unconventional oil and gas factory operation process, in order to ensure the benefit development, only one well is measured on each platform, and other wells are not measured. Once the well logging data of the horizontal section is incomplete, the comprehensive evaluation of the reservoir will lack the support of key parameters, resulting in insufficient basis for fracturing reconstruction, which leads to the fact that the single well production and EUR cannot be guaranteed. How to quickly and accurately carry out the comprehensive geological and engineering evaluation of unconventional reservoirs is a key problem for the normal and mainstream development of tight gas layers.

[0004] Through the combination application of a series of logging characteristic technologies, the drilling fluid or rock sample is analyzed during drilling to realize the analysis of the properties of the tight gas reservoir while drilling. Through the establishment of the reservoir "five property" quantitative characterization method based on the logging parameters, the applicability of the geochemical comprehensive evaluation model is formed, which is combined with the logging evaluation model to form complementary advantages, to provide help for further deepening the exploration and development potential of oil and gas reservoirs, efficient increase of reserves and production. And it can solve the problem of insufficient basis for fracturing and testing caused by the distortion or loss of logging data in complex well conditions, save the completion and logging time, improve the construction efficiency, and provide support for the low-cost and efficient development of the work area. SUMMARY

[0005] The embodiment of the application provides a method and device for evaluating five properties of a tight sandstone gas reservoir, solves three technical problems in the prior art, wherein 1, fine identification of the tight sandstone gas reservoir in terms of lithology, physical property, gas content, brittleness and rock mechanics property is difficult, and a complete interpretation and evaluation technical system has not been formed; 2, there are many analysis parameters of the tight sandstone gas reservoir characteristics, and there is a multiple solution in comprehensive evaluation; and 3, the evaluation standard of the tight sandstone gas reservoir is not perfect, and the evaluation support is insufficient.

[0006] Other characteristics and advantages of the application will become apparent from the following detailed description, or will be learned by practice of the application.

[0007] According to a first aspect of the embodiment of the application, as shown in Figure 1 A method for evaluating five properties of a tight sandstone gas reservoir is provided, comprising:

[0008] Detailed information of difficulties in exploration and development of the tight sandstone gas reservoir is acquired, a supplementary scheme of conventional logging means is obtained through analysis of comprehensive production requirements and logging technical characteristics;

[0009] The tight sandstone gas layer logging technology series is obtained through integration and matching processing of unconventional means according to the supplementary scheme of the conventional logging means, wherein the integration and matching processing of the unconventional means includes geochemistry, elements and rock and mineral scanning;

[0010] The basis for logging five-property evaluation is obtained through application of logging characteristic technology combination to collection of mineral content, total hydrocarbon, brittleness index and Poisson ratio parameters based on the tight sandstone gas layer logging technology series;

[0011] The tight sandstone gas reservoir quality model is established through correlation analysis of each parameter and automatic allocation of evaluation index weight of the main component analysis algorithm according to the basis for logging five-property evaluation;

[0012] The tight sandstone gas reservoir evaluation standard based on reservoir comprehensive quality is obtained through application of the comprehensive quality calculation method and combination of gas testing data according to the tight sandstone gas reservoir quality model, and the reservoir is classified into types I, II and III.

[0013] According to a second aspect of the embodiment of the application, as shown in Figure 2 A device for evaluating five properties of a tight sandstone gas reservoir is provided, comprising:

[0014] The acquisition module is configured to acquire detailed information of difficulties in exploration and development of the tight sandstone gas reservoir, and obtain a supplementary scheme of conventional logging means through analysis of comprehensive production requirements and logging technical characteristics;

[0015] Processing module: for the supplementary scheme according to the conventional logging means, through the integrated matching processing of unconventional means, the tight sandstone gas layer logging technology series is obtained, wherein the integrated matching processing of unconventional means includes geochemistry, elements and rock and mineral scanning;

[0016] Collection module: for based on the tight sandstone gas layer logging technology series, through the application of logging characteristic technology combination to the collection of mineral content, total hydrocarbon, brittleness index, Poisson ratio parameter, the basis of logging five nature evaluation is obtained;

[0017] Establishment module: for according to the basis of logging five nature evaluation, through the correlation analysis of each parameter and the automatic allocation of evaluation index weight by principal component analysis algorithm, the tight sandstone gas reservoir quality model is established;

[0018] Combination module: for according to the tight sandstone gas reservoir quality model, through the application of comprehensive quality calculation method and the combination of gas testing data, the tight sandstone gas reservoir evaluation standard based on reservoir comprehensive quality is obtained, and the reservoir is divided into class I, class II and class III.

[0019] According to the third aspect of the embodiment of the application, a tight sandstone gas reservoir five nature evaluation device is provided, comprising a processor and a memory, the memory stores computer program instructions capable of being executed by the processor, and the processor executes the computer program instructions to realize the steps of the method according to any one of the first aspect.

[0020] According to the fourth aspect of the embodiment of the application, a computer readable storage medium is provided, the computer readable storage medium stores computer program instructions, and the computer program instructions are executed by a processor to make the processor realize the steps of the method according to any one of the first aspect.

[0021] In the application, the lithology, physical property, gas content, brittleness and rock mechanics characteristics of the tight sandstone gas reservoir are quantitatively analyzed during the drilling process, the reservoir comprehensive quality is evaluated in real time, the reservoir heterogeneity is identified, the geological engineering fine evaluation is realized, and the scientific basis for fracturing layer selection is provided.

[0022] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the application. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings herein are incorporated into the specification and form part of the specification, show embodiments consistent with the application, and together with the specification serve to explain the principles of the application. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0024] Figure 1 A flow chart of a method for evaluating five properties of a tight sand gas reservoir is shown in an embodiment;

[0025] Figure 2 A structure diagram of a device for evaluating five properties of a tight sand gas reservoir is shown in an embodiment;

[0026] Figure 3 A structure diagram of a device for evaluating five properties of a tight sand gas reservoir is shown in an embodiment;

[0027] Figure 4 A comprehensive diagram of well logging five property evaluation of YQ1 in a method for evaluating five properties of a tight sand gas reservoir is shown in an embodiment. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0029] In addition, the described features, structures or characteristics can be combined in any suitable way in one or more embodiments. In the following description, numerous specific details are provided to give a sufficient understanding of the embodiments of the present application. However, those skilled in the art will realize that the technical solutions of the present application can be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other cases, well-known methods, devices, implementations or operations are not shown or described in detail to avoid obscuring the aspects of the present application.

[0030] The block diagrams shown in the drawings are only functional entities, and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in the form of software, or in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0031] The flowcharts shown in the drawings are only exemplary illustrations, and do not necessarily include all contents and operations / steps, nor do they necessarily be executed in the described order. For example, some operations / steps can be further decomposed, and some operations / steps can be combined or partially combined, so the actual execution order can be changed according to the actual situation.

[0032] In the present application, a method for evaluating the five properties of tight sandstone gas reservoirs is provided, which solves three technical problems in the prior art. Among them, 1, the fine identification of the lithology, physical property, gas content, brittleness and rock mechanics of the tight sandstone gas reservoir is difficult, and a complete interpretation and evaluation system has not been formed; 2, there are many characteristic analysis parameters of the tight sandstone gas reservoir, and the comprehensive evaluation has multiple solutions; 3, the evaluation standard of the tight sandstone gas reservoir is not perfect, and the evaluation support is insufficient.

[0033] Specifically, Figure 1 A flowchart of the method for evaluating the five properties of tight sandstone gas reservoirs in one embodiment is shown. Around the single well high-yield target, the functions of various characteristic logging technologies such as elemental, geochemical and rock mineral scanning are accurately positioned, and digital means are applied to establish a comprehensive quality calculation model of tight sandstone gas reservoirs from the perspective of lithology, physical property, gas content, brittleness and mechanical property, form a comprehensive interpretation standard, provide sufficient basis for dividing Class I, II and III reservoirs, and realize fine evaluation. Figure 1 As shown, a method for evaluating the five properties of tight sandstone gas reservoirs is provided, which can include the following steps 100 to 500.

[0034] S100, obtain detailed information of the exploration and development difficulties of tight sandstone gas reservoirs, and obtain the supplementary scheme of conventional logging means through the analysis of comprehensive production requirements and logging technology characteristics.

[0035] It should be noted that in the process of exploration and development of tight sandstone gas reservoirs in step S100, it is necessary to fully understand the exploration difficulties, which include but are not limited to geological structure complexity, low permeability of reservoirs, poor fluid flowability and high development cost, etc. Obtaining this information usually involves geological exploration data, drilling logs, well logging data and existing production experience, and through in-depth analysis of these data, the key factors affecting the development of gas reservoirs can be identified. Next, combined with the production requirements, that is, considering economic benefits, development cycle, technical feasibility and other factors, as well as the characteristics of logging technology such as real-time monitoring, data acquisition accuracy and processing speed, the existing conventional logging means are evaluated. This step can make up for the shortcomings of conventional logging technology in the exploration and development of tight sandstone gas reservoirs, and improve the exploration efficiency and accuracy.

[0036] S200, according to the supplementary scheme of conventional logging means, through the integration and matching of unconventional means, a series of tight sandstone gas layer logging technologies are obtained, wherein the integration and matching of unconventional means includes geochemistry, elements and rock mineral scanning.

[0037] It should be noted that in the exploration and development of tight sandstone gas reservoirs, conventional logging methods may not provide sufficient information to accurately assess reservoir characteristics. Therefore, it is necessary to integrate supporting unconventional means to supplement the shortcomings of traditional methods, which include geochemical analysis (geochemistry), elemental analysis, and rock and mineral scanning technology. Among them, by analyzing the organic matter content, maturity, type, etc. in the reservoir rock, important information about the generation potential of hydrocarbon substances in the reservoir can be provided, and geochemical analysis usually involves extraction of rock samples, separation and quantitative analysis of organic matter; elemental analysis can reveal the composition of major and trace elements in the rock, and the distribution pattern of these elements may be related to the pore structure, permeability and flow characteristics of the fluid in the reservoir, and elemental analysis techniques include X-ray fluorescence spectroscopy and inductively coupled plasma mass spectrometry. Through high-resolution imaging techniques such as scanning electron microscopy and transmission electron microscopy, the microstructure of the rock can be observed, including pore size, shape and connectivity, which are crucial for fluid storage and flow.

[0038] Therefore, the integrated unconventional means in this step can significantly improve the understanding of the characteristics of tight sandstone gas layers, making the logging technology series more accurate and comprehensive. This not only helps to identify and evaluate potential gas reservoirs, but also optimizes drilling strategies and reduces development risks.

[0039] S300, based on the tight sandstone gas layer logging technology series, through the application of logging characteristic technology combination to collect mineral content, total hydrocarbon, brittleness index, Poisson's ratio parameters, the basis for logging five nature evaluation is obtained.

[0040] In this step, the tight sandstone gas reservoir logging five nature evaluation parameters are determined, including:

[0041] Elemental and rock and mineral scanning logging technology is applied to determine the content of clay minerals, siliceous minerals, calcite and dolomite minerals as evaluation parameters for fine lithology description of the whole well;

[0042] Rock and mineral scanning logging technology is applied to determine the parameters of longitudinal wave time difference, transverse wave time difference, porosity and fracture number to evaluate the reservoir physical properties;

[0043] Gas logging technology is applied to collect parameters such as total hydrocarbon, peak-to-base ratio, gas saturation, etc. to evaluate the gas content of the reservoir;

[0044] Elemental logging technology is applied to collect the brittleness index to evaluate the brittleness of the reservoir;

[0045] Rock and mineral scanning logging technology is applied to collect parameters such as Poisson's ratio, Young's modulus, etc. to evaluate the mechanical properties of the reservoir.

[0046] It can be understood that the application element, rock and mineral scanning logging technology, the content of clay minerals, siliceous minerals, calcite, dolomite and other minerals is determined as an evaluation parameter, and the lithology of the whole well is finely described. The high content of quartz and feldspar is a high-quality reservoir, and the high content of clay minerals, calcite, dolomite and other minerals is a dense reservoir. The rock and mineral scanning logging technology is applied to determine the parameters such as longitudinal wave time difference, transverse wave time difference, porosity and fracture number, and the reservoir physical property is evaluated. The high value of parameters such as longitudinal wave time difference, transverse wave time difference, porosity and fracture number is a high-quality reservoir, and vice versa. The gas logging technology is applied to collect parameters such as total hydrocarbon, peak-to-base ratio and gas saturation, and the reservoir gas content is evaluated. The high value of parameters such as total hydrocarbon, peak-to-base ratio and gas saturation is a high-quality reservoir, and vice versa. The element logging technology is applied to collect the brittleness index, and the reservoir brittleness is evaluated. The high value of the brittleness index is a high-quality reservoir, and vice versa. The rock and mineral scanning logging technology is applied to collect parameters such as Poisson's ratio and Young's modulus, and the mechanical property of the reservoir is evaluated. The low Poisson's ratio and high Young's modulus are a high-quality reservoir, and the high Poisson's ratio and low Young's modulus are a dense reservoir.

[0047] S400, according to the basis of mud logging five nature evaluation, through principal component analysis algorithm to analyze the correlation of each parameter and automatically distribute the weight of evaluation index, to establish the quality model of tight sandstone gas reservoir.

[0048] It should be noted that the step S400 includes S401, S402, S403 and S404.

[0049] S401, the grey correlation analysis algorithm is applied to analyze the correlation of index items reflecting the characteristics of the reservoir, and the correlation index of each parameter is determined, wherein the correlation index interval is 0-1;

[0050] S402, according to the correlation index of different parameters, the first 8 parameters with high evaluation value of reservoir fluid and engineering are selected, including clay mineral content, siliceous mineral content, porosity, total hydrocarbon, peak-to-base ratio, brittleness index, Poisson's ratio and Young's modulus parameters;

[0051] S403, according to the value of different technologies and different parameters, the principal component analysis algorithm is applied to calculate the weight of the first 8 parameters;

[0052] S404, according to the value interval of a single parameter, the weight of each value interval is specified, and the actual weight of a single parameter is calculated according to the evaluation parameter corresponding to each sample point. The weight values of single parameters are summed up to obtain the comprehensive quality index of the sample point.

[0053] Wherein, the weight value of the single parameter is summed to obtain the comprehensive quality index of the sample point, wherein the comprehensive quality index is a dimensionless parameter, the minimum value is 0, and the maximum value is 100, and the reservoir comprehensive quality increases with the increase of the value. In the process of drilling, the comprehensive quality is used to evaluate the reservoir while drilling, and after completion, the oil testing geological scheme can be optimized according to the reservoir comprehensive quality index.

[0054] It can be understood that in the step of the embodiment, according to the analysis results of each single technology, there are more technologies and parameters participating in the reservoir evaluation at present, reaching 14, and each parameter has its own evaluation standard. The traditional data statistical method has strong multi-solution in application. How to obtain accurate comprehensive evaluation conclusion according to multiple technologies and multiple parameters is a difficult problem and the key to improve the accuracy of comprehensive interpretation and evaluation.

[0055] The principal component analysis algorithm is innovatively applied to analyze the correlation of each parameter, and the weight of the evaluation index is automatically distributed according to the correlation of each parameter, so that the evaluation method is improved from 'empirical' to'scientific', and the calculation method of comprehensive quality is established to realize fine quantitative evaluation. The specific calculation method is as follows:

[0056] A, the grey correlation analysis algorithm is applied to analyze the correlation of 15 indexes reflecting the characteristics of the reservoir, to determine the correlation index of each parameter. The correlation index interval is 0-1, and the closer to 1, the better the correlation.

[0057] B, according to the correlation index of different parameters, the first 8 parameters with high evaluation value for reservoir fluid and engineering are selected, including clay mineral content, siliceous mineral content, porosity, total hydrocarbon, peak base ratio, brittleness index, Poisson ratio, Young's modulus and other parameters.

[0058] C, according to the value of different technologies and different parameters, the principal component analysis algorithm is applied to calculate the weight Wi of the 8 parameters, i=1, 2, 3...8. The higher the weight, the greater the value.

[0059] D, according to the value interval of the single parameter, the weight Cj of each value interval is specified, j=1, 0.7, 0.5, and the value interval of the single parameter is more favorable to the positive evaluation of the reservoir.

[0060] D, according to the evaluation parameters corresponding to each sample point, the actual weight Qi of the single parameter is calculated, i=1, 2, 3...8:

[0061] Qi=Wi×Cj

[0062] E, the weight value of the single parameter is summed to obtain the comprehensive quality index RQ of the sample point:

[0063] RQ=∑Qi×100

[0064] Wherein, the comprehensive quality index is a dimensionless parameter, the minimum value is 0, the maximum value is 100, the larger the value is, the higher the reservoir comprehensive quality is, the reservoir is evaluated during drilling by using the comprehensive quality, and after completion, the oil testing geological scheme can be optimized according to the reservoir comprehensive quality index.

[0065] S500, according to the dense sandstone gas reservoir quality model, the application of the comprehensive quality calculation method and the combination of the gas testing data, the dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality is obtained, and the reservoir is divided into class I, class II and class III.

[0066] It should be noted that the step S500 includes S501, S502 and S503.

[0067] S501, according to the preliminary collected mineral content, total hydrocarbon, brittleness index and Poisson ratio key parameter data, the data set under the unified scale is obtained through data cleaning, data standardization and data normalization processing;

[0068] S502, the high-dimensional data set in the data set is converted into a low-dimensional data set through the principal component analysis algorithm, the main variation trend in the data is extracted, the covariance matrix of the data set is calculated, and the eigenvalue and eigenvector are found through characteristic decomposition, according to the size of the eigenvalue, the weight of each principal component is allocated, the larger the eigenvalue is, the higher the contribution of the corresponding principal component to the data is, and then the relative importance of each evaluation index is obtained;

[0069] S503, the comprehensive quality score of the reservoir is calculated by using the weighted summation method, the scoring of the reservoir quality is refined by combining the fuzzy mathematics theory, and the dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality is obtained by combining the gas testing data according to the comprehensive quality score, and the division of the reservoir is realized.

[0070] Wherein, the reservoir is divided into class I, class II and class III, wherein the reservoir quality interval corresponding to the reservoir of class I is greater than 0.8%, the reservoir quality interval corresponding to the reservoir of class II is between 0.7% and 0.8%, and the reservoir quality interval corresponding to the reservoir of class III is between 0.5% and 0.7%.

[0071] It should be noted that in step S501, the data cleaning process includes identifying and handling missing values, outliers, or erroneous data. For example, missing values ​​can be imputed using interpolation methods, or outliers can be identified and removed using statistical methods. Data standardization aims to eliminate the influence of different parameter units and magnitudes, requiring the data to be converted to a standard normal distribution with a mean of 0 and a standard deviation of 1. The data is also scaled to the [0,1] interval to facilitate comparisons between different parameters. Normalization can be achieved using the max-min method. After data preprocessing, a dataset with a uniform scale is obtained, providing a clean and standardized data foundation for subsequent principal component analysis.

[0072] In step S502, the covariance matrix of the standardized data is calculated to quantify the linear relationship between different parameters. The covariance matrix is ​​then subjected to eigenvalue decomposition to obtain eigenvalues ​​and eigenvectors. Eigenvectors indicate the main directions of data variation, while eigenvalues ​​represent the amount of data variation in these directions. Weights are assigned to each principal component based on the magnitude of the eigenvalues. Larger eigenvalues ​​indicate a stronger explanatory power for the principal component, thus giving it a higher weight in the overall quality evaluation. This process extracts the main trends in the data, transforms the high-dimensional dataset into a low-dimensional dataset, and determines the relative importance of each evaluation indicator.

[0073] In step S503, the overall quality score of the reservoir is calculated by weighted summation using the weights and principal component scores obtained from PCA. The calculation formula is as follows:

[0074]

[0075] In the formula, wi is the weight of the i-th principal component, and pi is the score of the i-th principal component.

[0076] Fuzzy mathematics theory is applied to adjust the comprehensive quality score to more accurately reflect the actual quality of the reservoir. Based on the comprehensive quality score and gas testing data, evaluation criteria are established to classify the reservoir into different categories, such as Class I, II, and III. Therefore, a comprehensive evaluation of the reservoir quality is conducted, and corresponding development strategies are formulated based on the evaluation results to optimize resource development and utilization.

[0077] In this embodiment, specifically, as Figure 4 As shown, Figure 4 This is a comprehensive logging performance evaluation chart for well YQ1. The data on the right side of the well depth chart are all logging performance analysis parameters for tight sandstone gas reservoirs. Based on the parameter distribution characteristics and reservoir comprehensive quality calculation methods, the comprehensive reservoir quality can be calculated. Combined with the gas reservoir comprehensive quality classification and evaluation standards, the reservoir category of this well was classified, interpreting 5.8m / 4 layers of Class II and 3.1m / 4 layers of Class III. Gas testing was conducted on the Class II layers, and the unobstructed flow rate reached 130,200 cubic meters.

[0078] In summary, this invention establishes a comprehensive quality calculation model for tight sandstone gas reservoirs from the perspective of five aspects: lithology, physical properties, gas content, brittleness, and mechanical properties. This model forms a comprehensive interpretation standard, providing sufficient basis for classifying reservoirs into Class I, II, and III, and enabling precise evaluation.

[0079] This embodiment provides a device for evaluating the five properties of tight sandstone gas reservoirs, such as... Figure 2 As shown, the device includes:

[0080] Acquisition Module 701: Used to acquire detailed information on the difficulties in exploration and development of tight sandstone gas reservoirs. After analyzing the comprehensive production requirements and logging technology characteristics, a supplementary solution for conventional logging methods is obtained.

[0081] Processing module 702: Used to obtain a series of tight sandstone gas layer logging technologies by integrating unconventional methods with a supplementary scheme to conventional logging methods. The integrated processing of unconventional methods includes geochemistry, elemental analysis, and rock and mineral scanning.

[0082] Acquisition Module 703: Used for logging technology series based on tight sandstone gas reservoirs, and through the application of a combination of logging-specific technologies, to acquire parameters such as mineral content, total hydrocarbons, brittleness index, and Poisson's ratio, thereby obtaining the basis for evaluating the five logging properties;

[0083] Module 704: This module is used to establish a tight sandstone gas reservoir quality model based on the five logging properties evaluation criteria, through principal component analysis algorithm to analyze the correlation of various parameters and automatically allocate the weights of evaluation indicators.

[0084] Combined with module 705: Based on the tight sandstone gas reservoir quality model, through the application of comprehensive quality calculation methods and the combination of gas testing data, the evaluation standard of tight sandstone gas reservoir based on comprehensive reservoir quality is obtained, and the reservoir is classified into categories I, II, and III.

[0085] Furthermore, the determination of the five-property evaluation parameters for tight sandstone gas reservoir logging in the acquisition module includes:

[0086] First application unit: used to apply elemental and rock and mineral scanning logging technology to determine the content of clay minerals, silica minerals, calcite and dolomite minerals as evaluation parameters, and to perform fine lithological characterization of the whole well.

[0087] The second application unit is used to apply rock and mineral scanning logging technology to determine parameters such as P-wave transit time, S-wave transit time, porosity, and fracture number, and to evaluate reservoir properties.

[0088] The third application unit is used to apply gas logging technology to collect parameters such as total hydrocarbons, peak-to-base ratio, and gas saturation to evaluate reservoir gas content.

[0089] The fourth application unit is used for applying element logging technology, collecting brittleness index, and evaluating reservoir brittleness.

[0090] The fifth application unit is used for applying rock and mineral scanning logging technology, collecting Poisson's ratio and Young's modulus and the like, and evaluating reservoir mechanical properties.

[0091] Further, the establishing module comprises:

[0092] The analysis unit is used for applying grey correlation analysis algorithm to perform correlation analysis on index items reflecting reservoir characteristics, and determining correlation indexes of various parameters, wherein the correlation index interval is 0-1.

[0093] The selecting unit is used for selecting the first 8 parameters with high evaluation value for reservoir fluid and engineering according to the correlation indexes of different parameters, wherein the parameters include clay mineral content, siliceous mineral content, porosity, total hydrocarbon, peak base ratio, brittleness index, Poisson's ratio and Young's modulus.

[0094] The calculating unit is used for applying principal component analysis algorithm to calculate the weight of the first 8 parameters according to the value of different technologies and different parameters.

[0095] The summing unit is used for defining the weight of each value interval according to the value interval of a single parameter, calculating the actual weight of the single parameter according to the evaluation parameter corresponding to each sample point, summing the weight values of the single parameters, and obtaining the comprehensive quality index of the sample point.

[0096] Further, the combining module comprises:

[0097] The processing collection unit is used for obtaining a data set in a unified scale through data cleaning, data standardization and data normalization processing according to the key parameter data of mineral content, total hydrocarbon, brittleness index and Poisson's ratio collected initially.

[0098] The weight distribution unit is used for converting the high-dimensional data set in the data set into a low-dimensional data set by principal component analysis algorithm, extracting the main variation trend in the data, calculating the covariance matrix of the data set, finding the eigenvalue and eigenvector through characteristic decomposition, distributing the weight of each principal component according to the size of the eigenvalue, and obtaining the relative importance of each evaluation index.

[0099] The evaluation unit is used for calculating the comprehensive quality score of the reservoir by using weighted summation method, refining the score of the reservoir quality by combining fuzzy mathematics theory, obtaining the evaluation standard of the tight sand gas reservoir based on the comprehensive quality of the reservoir according to the comprehensive quality score, and combining gas testing data, and realizing the division of the reservoir.

[0100] It should be noted that the specific manner in which the various modules perform operations in the above-described apparatus embodiments has already been described in detail in the method embodiments related thereto, and will not be described in detail here.

[0101] Corresponding to the above method embodiments, the present embodiment also provides a tight sand gas reservoir five nature evaluation device. The tight sand gas reservoir five nature evaluation device described below can be mutually corresponding to the tight sand gas reservoir five nature evaluation method described above.

[0102] Figure 3 is a block diagram of a tight sand gas reservoir five nature evaluation device 800 according to an exemplary embodiment. As shown, the tight sand gas reservoir five nature evaluation device 800 includes a processor 801 and a memory 802. The tight sand gas reservoir five nature evaluation device 800 also includes one or more of a multimedia component 803, an I / O interface 804, and a communication component 805. Figure 3

[0103] ​The processor 801 is configured to control overall operations of the tight sand gas reservoir five-property evaluation device 800 to complete all or part of the steps in the tight sand gas reservoir five-property evaluation method described above. The memory 802 is configured to store various types of data to support the operations of the tight sand gas reservoir five-property evaluation device 800. For example, the data can include instructions for any application or method operating on the tight sand gas reservoir five-property evaluation device 800, and application-related data such as contact data, sent and received messages, pictures, audio, video, and the like. The memory 802 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk. The multimedia component 803 can include a screen and an audio component. The screen can be a touch screen, for example, and the audio component is configured to output and / or input audio signals. For example, the audio component can include a microphone configured to receive external audio signals. The received audio signals can be further stored in the memory 802 or transmitted through the communication component 805. The audio component also includes at least one speaker configured to output audio signals. The I / O interface 804 provides an interface between the processor 801 and other interface modules, which can be a keyboard, a mouse, or a button, and the like. The buttons can be virtual buttons or physical buttons. The communication component 805 is configured to enable wired or wireless communication between the tight sand gas reservoir five-property evaluation device 800 and other devices. The wireless communication, such as Wi-Fi, Bluetooth, near field communication (NFC), 2G, 3G or 4G, or a combination of one or more of them, so the corresponding communication component 805 can include a Wi-Fi module, a Bluetooth module or an NFC module.

[0104] In an exemplary embodiment, the tight sand gas reservoir five-property evaluation device 800 can be implemented by one or more Application Specific Integrated Circuit (ASIC), Digital Signal Processor (DSP), Digital Signal Processing Device (DSPD), Programmable Logic Device (PLD), Field Programmable Gate Array (FPGA), controller, microcontroller, microprocessor or other electronic elements for executing the above-mentioned tight sand gas reservoir five-property evaluation method.

[0105] In another exemplary embodiment, a computer readable storage medium including program instructions is also provided, which, when executed by a processor, implement the steps of the above-mentioned tight sand gas reservoir five-property evaluation method. For example, the computer readable storage medium can be the above-mentioned memory 802 including program instructions, which can be executed by the processor 801 of the tight sand gas reservoir five-property evaluation device 800 to complete the above-mentioned tight sand gas reservoir five-property evaluation method.

[0106] Corresponding to the above method embodiment, the present embodiment also provides a readable storage medium, which can be referred to in conjunction with the above-mentioned tight sand gas reservoir five-property evaluation method.

[0107] The computer program stored on the readable storage medium, when executed by the processor, implements the steps of the above-mentioned tight sand gas reservoir five-property evaluation method of the method embodiment.

[0108] In summary, in the process of tight sand gas layer logging, the present application forms a tight sand gas reservoir "five-property" evaluation method by the comprehensive application of gas logging conventional technology and new technologies such as rock and mineral scanning and element analysis, realizes the optimization of heterogeneous reservoirs, and provides support for high and stable production of horizontal wells. Through high-precision electron microscopy scanning, minerals and pores are observed at the micro-nanometer scale, geological understanding is improved, and the problem of distortion or loss of logging data caused by complex conditions is solved. In addition, the analysis can be performed while drilling, saving the time of completion logging, improving the construction efficiency, and reducing the engineering risk. The achievement has been applied in more than 20 wells, and the open flow capacity of 18 wells reaches more than 50,000 cubic meters.

[0109] The readable storage medium can be specifically a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various readable storage media that can store program codes.

[0110] The above merely provides an example of the present application, and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the scope of the claims of the present application.

Claims

1. A method of evaluating the properties of a tight sand gas reservoir, characterized in that, The application relates to a tight sandstone gas reservoir evaluation method. The method comprises the following steps: S1, acquiring detailed information about difficulties in exploration and development of a tight sandstone gas reservoir, and analyzing comprehensive production requirements and logging technical characteristics to obtain a supplement scheme of conventional logging means; S2, according to the supplement scheme of the conventional logging means, performing integrated matching processing on unconventional means to obtain a tight sandstone gas layer logging technology series, wherein the integrated matching processing on the unconventional means comprises geochemistry, elements and rock and mineral scanning; S3, based on the tight sandstone gas layer logging technology series, performing application logging characteristic technology combination on collection of mineral content, total hydrocarbon, brittleness index and Poisson ratio parameters to obtain a basis for logging five-property evaluation; S4, according to the basis for logging five-property evaluation, performing correlation analysis on each parameter and automatic distribution of evaluation index weight through a principal component analysis algorithm to establish a tight sandstone gas reservoir quality model; 2. The method of FIG. 1, further comprising: S5, according to the tight sandstone gas reservoir quality model, applying a comprehensive quality calculation method and combining with test gas data to obtain a tight sandstone gas reservoir evaluation standard based on reservoir comprehensive quality, and realizing classification of reservoirs into types I, II and III. In the step S3, the basis for logging five-property evaluation is obtained, wherein the determination of tight sandstone gas reservoir logging five-property evaluation parameters comprises the following steps: applying element and rock and mineral scanning logging technology to determine clay mineral content, siliceous mineral content, calcite mineral content and dolomite mineral content as evaluation parameters to finely depict full-well lithology; applying rock and mineral scanning logging technology to determine longitudinal wave time difference, transverse wave time difference, porosity and fracture number parameters to evaluate reservoir physical properties; applying gas logging technology to collect total hydrocarbon, peak base ratio and gas saturation parameters to evaluate reservoir gas content; applying element logging technology to collect brittleness index to evaluate reservoir brittleness; 3. The method of Figure 1, further comprising: determining a fracture density of the reservoir based on the fracture density model. applying rock and mineral scanning logging technology to collect Poisson ratio and Young's modulus parameters to evaluate reservoir mechanical properties. In the step S4, the tight sandstone gas reservoir quality model is established through correlation analysis on each parameter and automatic distribution of evaluation index weight by the principal component analysis algorithm, and the method comprises the following steps: applying grey correlation analysis algorithm to perform correlation analysis on index items reflecting reservoir characteristics to determine correlation indexes of each parameter, wherein the correlation index interval is 0-1; selecting the first 8 parameters with high evaluation value on reservoir fluid and engineering from different parameters according to the correlation indexes of different parameters, wherein the parameters include clay mineral content, siliceous mineral content, porosity, total hydrocarbon, peak base ratio, brittleness index, Poisson ratio and Young's modulus parameters; applying the principal component analysis algorithm to calculate the weight of the first 8 parameters according to the value of different technologies and different parameters; 4. The method of Figure 3, further comprising: according to the value interval of a single parameter, the weight of each value interval is specified, the actual weight of a single parameter is calculated according to the corresponding evaluation parameter of each sample point, the weight values of the single parameters are summed up to obtain the comprehensive quality index of the sample point. In the step of summing up the weight values of the single parameters to obtain the comprehensive quality index of the sample point, the comprehensive quality index is a dimensionless parameter, the minimum value is 0, the maximum value is 100, and the reservoir comprehensive quality increases with the increase of the value. In the process of drilling, the comprehensive quality is used for drilling evaluation of the reservoir, and after completion, the test oil geological scheme can be optimized according to the reservoir comprehensive quality index.

5. The method of FIG. 1, further comprising: The dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality is obtained according to the dense sandstone gas reservoir quality model, the application of the comprehensive quality calculation method and the combination of the gas testing data, and the dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality includes: According to the preliminary collected mineral content, total hydrocarbon, brittleness index and Poisson ratio key parameter data, the data set under the unified scale is obtained through data cleaning, data standardization and data normalization processing; The high-dimensional data set in the data set is converted into a low-dimensional data set through the principal component analysis algorithm, the main change trend in the data is extracted, the covariance matrix of the data set is calculated, and the eigenvalue and eigenvector are found through characteristic decomposition, the weight of each principal component is allocated according to the size of the eigenvalue, the contribution degree of the corresponding principal component to the data is higher when the eigenvalue is larger, and then the relative importance of each evaluation index is obtained; The comprehensive quality score of the reservoir is calculated by using the weighted summation method, the scoring of the reservoir quality is refined by combining the fuzzy mathematics theory, and the dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality is obtained according to the comprehensive quality score and the gas testing data, and the division of the reservoir is realized.

6. The method of Figure 1, further comprising: The reservoir is divided into types I, II and III, the reservoir quality interval corresponding to the type I reservoir is greater than 0.8%, the reservoir quality interval corresponding to the type II reservoir is between 0.7% and 0.8%, and the reservoir quality interval corresponding to the type III reservoir is between 0.5% and 0.7%.

7. A device for evaluating the properties of a tight sand gas reservoir, characterized in that it comprises: It includes: The acquisition module is used to acquire the detailed information of the dense sandstone gas reservoir exploration and development difficulties, and the supplementary scheme of the conventional logging method is obtained through the analysis of the comprehensive production requirements and the logging technical characteristics; The processing module is used to obtain the dense sandstone gas layer logging technology series through the integrated matching processing of the unconventional means according to the supplementary scheme of the conventional logging method, and the integrated matching processing of the unconventional means includes geochemistry, elements and rock and mineral scanning; The acquisition module is used to obtain the basis for logging five-property evaluation through the application of logging characteristic technology combination to the acquisition of mineral content, total hydrocarbon, brittleness index and Poisson ratio parameters based on the dense sandstone gas layer logging technology series; The establishment module is used to establish the dense sandstone gas reservoir quality model through the correlation analysis of each parameter and the automatic allocation of the evaluation index weight of the principal component analysis algorithm according to the basis for logging five-property evaluation; The combination module is used to obtain the dense sandstone gas reservoir evaluation standard based on the reservoir comprehensive quality and realize the division of the reservoir into types I, II and III according to the dense sandstone gas reservoir quality model, the application of the comprehensive quality calculation method and the combination of the gas testing data.

8. The apparatus of claim 7, wherein, The determination of the dense sandstone gas reservoir logging five-property evaluation parameters in the acquisition module includes: The first application unit is used to determine the clay mineral, siliceous mineral, calcite and dolomite mineral content as the evaluation parameters for the fine lithology description of the whole well by applying the element and rock and mineral scanning logging technology; The second application unit is used to determine the longitudinal wave time difference, transverse wave time difference, porosity and fracture number parameters to evaluate the reservoir physical property by applying the rock and mineral scanning logging technology; The third application unit is used to collect the total hydrocarbon, peak base ratio and gas saturation parameters to evaluate the reservoir gas content by applying the gas logging technology. The fourth application unit is used for applying element logging technology, collecting brittleness index, and evaluating reservoir brittleness. The fifth application unit is used for applying rock and mineral scanning logging technology, collecting Poisson ratio and Young's modulus and the like, and evaluating reservoir mechanical properties.

9. The apparatus of claim 7, wherein, The establishing module comprises: The analysis unit is used for applying grey correlation analysis algorithm to perform correlation analysis on index items reflecting reservoir characteristics, and determining correlation indexes of various parameters, wherein the correlation index interval is 0-1. The selection unit is used for selecting the first 8 parameters with high evaluation value for reservoir fluid and engineering according to the correlation indexes of different parameters, wherein the parameters include clay mineral content, siliceous mineral content, porosity, total hydrocarbon, peak base ratio, brittleness index, Poisson ratio and Young's modulus. The calculation unit is used for applying principal component analysis algorithm to calculate the weight of the first 8 parameters according to the value of different technologies and different parameters. The summation unit is used for defining the weight of each value interval according to the value interval of a single parameter, calculating the actual weight of the single parameter according to the evaluation parameter corresponding to each sample point, summing the weight value of the single parameter, and obtaining the comprehensive quality index of the sample point.

10. The resource evaluation device according to claim 7, wherein The combination module comprises: The processing collection unit is used for obtaining data set in a unified scale through data cleaning, data standardization and data normalization processing according to the key parameter data of mineral content, total hydrocarbon, brittleness index and Poisson ratio collected initially. The weight distribution unit is used for converting high-dimensional data set in the data set into low-dimensional data set through principal component analysis algorithm, extracting the main change trend in the data, calculating the covariance matrix of the data set, finding eigenvalues and eigenvectors through characteristic decomposition, distributing the weight of each principal component according to the size of the eigenvalues, and obtaining the relative importance of each evaluation index. The evaluation unit is used for calculating the comprehensive quality score of the reservoir by using weighted summation method, refining the score of the reservoir quality by combining fuzzy mathematics theory, obtaining the evaluation standard of the tight sand gas reservoir based on the comprehensive quality of the reservoir according to the comprehensive quality score, and combining the gas testing data, and realizing the division of the reservoir.

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