Shale gas layer effectiveness evaluation method, device, equipment and storage medium

Abstract

The application discloses a shale gas layer effectiveness evaluation method, device, equipment and a storage medium. The method comprises the following steps: acquiring acoustic logging curve data, total hydrocarbon content values and Poisson's ratio and volume compressibility coefficient of each shale gas reservoir of a target well; constructing a Poisson's ratio curve and a volume compressibility coefficient curve; superimposing the Poisson's ratio curve and the volume compressibility coefficient curve in the same curve channel to obtain an envelope area of the two curves; determining the category of each shale gas reservoir based on the envelope area; determining a comprehensive evaluation index of each shale gas reservoir according to the Poisson's ratio value, the volume compressibility coefficient value and the total hydrocarbon content value corresponding to each shale gas reservoir; establishing a crossplot with the comprehensive evaluation index as the vertical coordinate and the acoustic logging curve data as the horizontal coordinate; and evaluating the effectiveness of the shale gas reservoir based on the distribution of the shale gas reservoirs of each category in the crossplot. The application realizes efficient and accurate evaluation of the effectiveness of the shale gas reservoir.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of oil and gas drilling pressure control, and particularly to a method, apparatus, equipment and storage medium for evaluating the effectiveness of shale gas reservoirs. Background Technology

[0002] Accurately assessing shale gas availability is a core prerequisite for achieving economical and efficient shale gas development, directly impacting the selection of fracturing targets, horizontal well trajectory design, and development strategy formulation. However, current traditional evaluation methods are limited by single-parameter or simple linear superposition models, revealing numerous limitations when facing the complex characteristics of shale gas reservoirs, characterized by strong heterogeneity, multi-scale coupling, and multiple mechanisms of occurrence. Furthermore, existing multi-parameter collaborative analysis methods suffer from fixed parameter weights, neglecting dynamic differences in geological conditions. In deep shale, traditional models cannot adaptively adjust weights, and they also ignore the nonlinear relationship between rock mechanics parameters and total hydrocarbon manifestations, resulting in low evaluation accuracy. These limitations trigger a chain reaction of problems in engineering applications, leading to low fracturing efficiency, increased single-well costs, and significant deviations in reserve assessment. Summary of the Invention

[0003] The purpose of this invention is to provide at least one method, apparatus, device, and storage medium for evaluating the effectiveness of shale gas reservoirs, which can at least solve the technical problem of inaccurate judgment of the effectiveness of shale gas reservoirs in the prior art.

[0004] To address the aforementioned technical problems, at least one embodiment of this application provides a method for evaluating the effectiveness of shale gas reservoirs, comprising:

[0005] Acquire sonic logging curve data of the target well, total hydrocarbon content during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir;

[0006] Based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, a Poisson's ratio curve and a volumetric compressibility coefficient curve are constructed. The Poisson's ratio curve and the volumetric compressibility coefficient curve are superimposed on the same curve channel to obtain the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve.

[0007] The category of each shale gas reservoir is determined based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve.

[0008] The comprehensive evaluation index of each shale gas reservoir is determined based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content.

[0009] A cross plot is established with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis. The effectiveness of the shale gas reservoir is evaluated based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0010] At least one embodiment of this application also provides a shale gas reservoir effectiveness evaluation device, comprising:

[0011] The acquisition module is used to acquire sonic logging curve data of the target well, total hydrocarbon content values ​​during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir.

[0012] The envelope area determination module is used to construct Poisson's ratio curves and volume compressibility coefficient curves based on the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir, and to superimpose the Poisson's ratio curves and volume compressibility coefficient curves on the same curve track to obtain the envelope area of ​​the Poisson's ratio curves and volume compressibility coefficient curves.

[0013] The category determination module is used to determine the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve;

[0014] The comprehensive evaluation index determination module is used to determine the comprehensive evaluation index of each shale gas reservoir based on the Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content of each shale gas reservoir.

[0015] The effectiveness evaluation module is used to establish a cross plot with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis, and to evaluate the effectiveness of the shale gas reservoir based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0016] At least one embodiment of this application also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described shale gas reservoir effectiveness evaluation method.

[0017] At least one embodiment of this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described shale gas reservoir effectiveness evaluation method.

[0018] The shale gas reservoir effectiveness evaluation method, apparatus, electronic equipment, and computer-readable storage medium provided in this application utilize the overlap characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values, to establish a comprehensive evaluation index. It also determines the range of different comprehensive evaluation indices for different reservoirs, enabling rapid reservoir effectiveness evaluation and improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation. Furthermore, it quantitatively characterizes the "high brittleness-low compressibility" characteristics of the reservoir through the overlap area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient, and directly reflects the degree of hydrocarbon enrichment by combining it with total hydrocarbon displays, achieving accurate judgment of shale gas reservoir effectiveness. This solves the problem of inefficiency in shale gas reservoir effectiveness evaluation.

[0019] In some optional embodiments, the steps of acquiring sonic logging data of the target well, total hydrocarbon content during drilling, and Poisson's ratio and volumetric compressibility of each shale gas reservoir are further included before:

[0020] The characteristic parameters of each shale stratum in the target well are obtained, including porosity, organic carbon content, silica content and clay content.

[0021] Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

[0022] In some optional embodiments, the step of determining the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility curve includes:

[0023] Shale gas reservoirs whose envelope area is greater than or equal to a first preset value are classified as Class I shale gas reservoirs;

[0024] And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir;

[0025] And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir;

[0026] The first preset value is greater than the second preset value.

[0027] In some optional embodiments, the calculation expression for the comprehensive evaluation index is as follows:

[0028] VI=α(V norm +C b,norm )+β·TG nrom

[0029] Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

[0030] In some optional embodiments, the step of determining the comprehensive evaluation index of each shale gas reservoir based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content further includes:

[0031] The weighting coefficients in the comprehensive evaluation index are calculated based on the brittleness index and gas saturation.

[0032] The weighting coefficient is calculated using the following expression:

[0033]

[0034] β=1-α

[0035]

[0036] Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0037] In some optional embodiments, the step of determining the shale gas reservoir based on a preset numerical range of the characteristic parameters includes:

[0038] The shale layer that simultaneously meets the following criteria is identified as the shale gas reservoir: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%.

[0039] In some optional embodiments, the steps of acquiring sonic logging data of the target well, total hydrocarbon content during drilling, and Poisson's ratio and volumetric compressibility of each shale gas reservoir further include:

[0040] The Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content values ​​were normalized. Attached Figure Description

[0041] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0042] Figure 1 This is a flowchart of a shale gas reservoir effectiveness evaluation method provided in one embodiment of this application;

[0043] Figure 2 This is a flowchart of a shale gas reservoir effectiveness evaluation method provided in another embodiment of this application;

[0044] Figure 3 A schematic diagram of reservoir parameter superposition analysis provided for another embodiment of this application;

[0045] Figure 4 A cross-plot of the comprehensive evaluation index and sonic logging curve provided for another embodiment of this application;

[0046] Figure 5 A schematic diagram illustrating the effectiveness evaluation of shale gas reservoirs, provided for another embodiment of this application;

[0047] Figure 6 A schematic diagram of a shale gas reservoir effectiveness evaluation device provided for another embodiment of this application;

[0048] Figure 7 A schematic diagram of the structure of an electronic device provided for another embodiment of this application.

[0049] In the accompanying drawings, the same parts are referred to by the same reference numerals, and the drawings are not drawn to scale. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the various embodiments below is for ease of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0051] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this disclosure described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0052] It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases the steps shown or described may be executed in a different order than that shown here.

[0053] To facilitate understanding of the embodiments of this application, we will first introduce the relevant content of the prior art on evaluating the effectiveness of shale gas reservoirs using a single parameter or a simple linear superposition model.

[0054] Among the single rock mechanics parameters, Poisson's ratio is often used to characterize rock brittleness, with a low ν value corresponding to high brittleness. However, its practical application is significantly flawed. For example, some low-ν value sections in the Wufeng Formation shale of the Sichuan Basin have high clay mineral content, making it difficult to form an effective fracture network after fracturing, resulting in low production. This indicates that relying solely on Poisson's ratio ignores key factors such as mineral composition and the degree of development of natural fractures. The volume compressibility coefficient reflects the rock's ability to change volume under pressure. A high value usually indicates fracturing susceptibility, but its correlation with fracturing effectiveness decreases significantly in high-stress-difference formations. In a certain block of the Ordos Basin, a high volume compressibility coefficient section suffers from severe fracturing fluid loss due to the lack of microfracture development. The total hydrocarbon data has an interpretation blind spot, making it impossible to distinguish between the contributions of free gas and adsorbed gas. In some high total hydrocarbon data sections of the Longmaxi Formation shale in the Qijiang area of ​​Chongqing, the proportion of free gas is low, resulting in poor stable production capacity after fracturing. Furthermore, traditional methods lack effective correction algorithms when data anomalies are caused by non-reservoir factors. For example, a certain exploration well in Guizhou was misjudged due to the failure to remove interference from drilling fluid additives, resulting in high ineffective fracturing costs.

[0055] To address the aforementioned technical problem of inaccurate shale gas reservoir effectiveness assessment, this invention proposes a shale gas reservoir effectiveness evaluation method. The implementation details of this embodiment's shale gas reservoir effectiveness evaluation method are described below. These details are provided for ease of understanding and are not essential for implementing this solution.

[0056] Example 1:

[0057] The specific process of the shale gas reservoir effectiveness evaluation method in this embodiment can be described as follows: Figure 1 As shown, it includes:

[0058] Step 110: Obtain the sonic logging curve data of the target well, the total hydrocarbon content value during the drilling process, and the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir.

[0059] Specifically, total hydrocarbon content refers to the total volume fraction of hydrocarbon gases in drilling fluid, used to invert the content and distribution of oil and gas in underground reservoirs; Poisson's ratio describes the ratio of lateral strain to longitudinal strain when a material is subjected to uniaxial tension or compression, and in one example, it can be indirectly calculated from logging parameters such as sonic velocity and density. The volume compressibility coefficient describes the relative rate of change of a material's volume under pressure changes, and in one example, it can be indirectly calculated from logging parameters such as rock density and P-wave velocity.

[0060] In one example, during the drilling of a target shale gas well, equipment such as gas chromatographs are used to monitor the total hydrocarbon content in the drilling fluid in real time and record the total hydrocarbon display data. After well completion, high-precision logging instruments such as dipole sonic logging tools and lithology density logging tools are used to obtain P-wave, S-wave, density, gamma, neutron, and lateral logging data of the shale formation. The acquired P-wave, S-wave, density, gamma, neutron, and lateral logging data are imported into specialized data processing software to calculate the Poisson's ratio and volume compressibility of the shale formation.

[0061] In one example, logging, well logging, and core data from the target well are collected, and software is used to perform preliminary data processing to obtain the Poisson's ratio and volumetric compressibility of each shale gas reservoir.

[0062] Step 120: Construct Poisson's ratio curve and volumetric compressibility coefficient curve based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir. Superimpose the Poisson's ratio curve and volumetric compressibility coefficient curve on the same curve channel to obtain the envelope area of ​​the Poisson's ratio curve and volumetric compressibility coefficient curve.

[0063] Specifically, based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, curves showing the variation of Poisson's ratio with depth are constructed, namely, the Poisson's ratio curve and the volumetric compressibility coefficient curve. The dynamic relationship between the Poisson's ratio and the volumetric compressibility coefficient is converted into an overlay characteristic curve to analyze the synergistic relationship between the Poisson's ratio and the volumetric compressibility coefficient. That is, the synergistic variation characteristics of the Poisson's ratio curve and the volumetric compressibility coefficient curve are analyzed by superimposing them on the same curve. Specifically, the envelope area of ​​the overlay of the Poisson's ratio curve and the volumetric compressibility coefficient curve is obtained.

[0064] Step 130: Determine the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve.

[0065] Specifically, the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve is related to the determination of the category of each shale gas reservoir. Among them, the analysis based on the superposition of Poisson's ratio and volumetric compressibility coefficient shows that the size of the envelope area of ​​different categories of shale gas reservoirs is different.

[0066] Step 140: Determine the comprehensive evaluation index of each shale gas reservoir based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content.

[0067] Specifically, based on the superimposed analysis of reservoir parameters and the introduction of total hydrocarbon content, a comprehensive evaluation index for reservoir effectiveness is established. That is, the comprehensive evaluation index of each shale gas reservoir is determined according to the Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content of each shale gas reservoir.

[0068] Step 150: Establish a cross plot with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis, and evaluate the effectiveness of the shale gas reservoir based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0069] Specifically, based on the sensitivity of sonic logging curves to reservoirs, a cross-plot is established using a comprehensive evaluation index and sonic logging curves to determine the range of the comprehensive evaluation index for different levels of shale gas reservoirs. This enables the grading and evaluation of reservoirs in shale gas reservoir classification. Furthermore, different colors are used to represent different levels in specialized software for visualization, thereby achieving rapid evaluation of reservoir effectiveness and improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation.

[0070] In this embodiment, a comprehensive evaluation index is established using the overlap characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values. The range of different comprehensive evaluation indices for different reservoirs is determined, enabling rapid evaluation of reservoir effectiveness. This improves the accuracy and efficiency of shale gas reservoir effectiveness evaluation. Furthermore, the "high brittleness-low compressibility" characteristics of the reservoir are quantitatively characterized by the overlap area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. Combined with total hydrocarbon data, the degree of hydrocarbon enrichment is directly reflected, achieving accurate judgment of shale gas reservoir effectiveness. This solves the problem of inefficiency in shale gas reservoir effectiveness evaluation.

[0071] In some embodiments, the step of acquiring the sonic logging curve data of the target well, the total hydrocarbon content value during the drilling process, and the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir further includes:

[0072] The characteristic parameters of each shale stratum in the target well are obtained, including porosity, organic carbon content, silica content and clay content.

[0073] Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

[0074] Specifically, based on the collected logging and lithological data from the target wells, preliminary delineation of shale gas reservoirs is necessary. This involves using high-precision logging instruments such as dipole sonic logging tools and lithology density logging tools to acquire data on P-wave, S-wave, density, gamma ray, neutron, and lateral velocity of the shale formations. Based on these data, characteristic parameters such as Poisson's ratio, volumetric compressibility, porosity, gas saturation, permeability, organic carbon content, silica content, and clay content of the shale formations are calculated. The shale gas reservoirs are then identified based on these determined characteristic parameters.

[0075] In one example, based on experience or literature, the performance of various characteristic parameters of shale gas reservoirs is summarized, and then shale gas reservoirs are classified by pre-setting the numerical range of each characteristic parameter.

[0076] In some embodiments, the step of determining the shale gas reservoir based on a preset numerical range of the characteristic parameters includes:

[0077] The shale layer that simultaneously meets the following criteria is identified as the shale gas reservoir: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%.

[0078] Specifically, based on the collected logging and core data and the calculated porosity and total organic carbon (TOC) content, strata with TOC greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50% are preliminarily classified as shale gas reservoirs in this area.

[0079] Of course, in other embodiments, shale gas reservoirs can also be determined based on preset value ranges of other characteristic parameters, which is not a limitation herein.

[0080] In some embodiments, the steps of acquiring sonic logging curve data of the target well, total hydrocarbon content values ​​during drilling, and Poisson's ratio and volume compressibility of each shale gas reservoir further include:

[0081] The Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content values ​​were normalized.

[0082] Specifically, in order to eliminate the influence of dimensions and avoid inaccurate calculation of the comprehensive evaluation index of each shale gas reservoir, after obtaining the total hydrocarbon content value during the drilling process and the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir, it is necessary to normalize the Poisson's ratio, volume compressibility coefficient and total hydrocarbon content value so that their values ​​are between 0 and 1.

[0083] In one example, the normalization formula is:

[0084]

[0085] In the formula, y norm The curve is normalized, x min To find the minimum value of the curve that needs to be normalized, x max Let x be the maximum value of the curve to be normalized, and let x be the value of the curve to be normalized.

[0086] In some embodiments, the step of determining the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve includes:

[0087] Shale gas reservoirs whose envelope area is greater than or equal to a first preset value are classified as Class I shale gas reservoirs;

[0088] And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir;

[0089] And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir;

[0090] The first preset value is greater than the second preset value.

[0091] Specifically, to ensure the evaluation of shale gas reservoir effectiveness, it is necessary to classify shale gas reservoirs to facilitate the observation of the comprehensive evaluation index of shale gas reservoir effectiveness in subsequent cross-plots. Specifically, shale gas reservoirs are divided into three categories. In other embodiments, depending on the specific circumstances, shale gas reservoirs may be divided into two categories, or more than four categories; this is not a limitation. Specifically, shale gas reservoirs with an envelope area greater than or equal to a first preset value are classified as Class I shale gas reservoirs; shale gas reservoirs with an envelope area greater than or equal to a second preset value but less than the first preset value are classified as Class II shale gas reservoirs; and shale gas reservoirs with an envelope area less than the second preset value are classified as Class III shale gas reservoirs, where the first preset value is greater than the second preset value. In other words, Type I shale gas reservoirs exhibit a large envelope area between Poisson's ratio and volumetric compressibility; Type II shale gas reservoirs exhibit a relatively large envelope area between Poisson's ratio and volumetric compressibility, but smaller than that of Type I shale gas reservoirs; and Type III shale gas reservoirs exhibit the smallest envelope area between Poisson's ratio and volumetric compressibility, smaller than that of Type II shale gas reservoirs. Thus, quantitatively characterizing the "high brittleness-low compressibility" of reservoirs based on the overlapping area of ​​the curves of Poisson's ratio and volumetric compressibility facilitates accurate assessment of the effectiveness of shale gas reservoirs.

[0092] In one example, an overlay analysis can be performed by combining parameters that reflect the influence of rock mechanics, such as P-wave velocity, S-wave velocity, Lamé coefficient, or Young's modulus.

[0093] In some embodiments, the calculation expression for the comprehensive evaluation index is:

[0094] VI=α(V norm +C b,norm )+β·TG norm

[0095] Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

[0096] In some embodiments, the step of determining the comprehensive evaluation index of each shale gas reservoir based on the Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content of each shale gas reservoir further includes:

[0097] The weighting coefficients in the comprehensive evaluation index are calculated based on the brittleness index and gas saturation.

[0098] The weighting coefficient is calculated using the following expression:

[0099]

[0100] β=1-α

[0101]

[0102] Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0103] Specifically, based on the results of superimposed analysis of reservoir parameters, and by incorporating total hydrocarbon content values, a comprehensive evaluation index for reservoir effectiveness is established. The weighting coefficients in this comprehensive evaluation index can be determined using methods such as neural networks, factor analysis, and empirical analysis.

[0104] This embodiment of the shale gas reservoir effectiveness evaluation method quantitatively characterizes the "high brittleness-low compressibility" characteristics of the reservoir by using the overlap area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. It also combines this with total hydrocarbon values ​​to directly reflect the degree of hydrocarbon enrichment. In other words, it establishes a comprehensive evaluation index using the overlap characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values, to accurately determine the effectiveness of shale gas reservoirs. This method addresses the inefficiency of shale gas reservoir effectiveness evaluation, defines the range of different comprehensive evaluation indices for different reservoirs, and enables rapid evaluation of reservoir effectiveness, thus improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation.

[0105] Example 2:

[0106] Another embodiment of this application relates to a method for evaluating the effectiveness of shale gas reservoirs based on the overlap characteristics of Poisson's ratio and volumetric compressibility coefficient and total hydrocarbon indication, comprising the following steps:

[0107] a. Data collection and preprocessing;

[0108] b. Shale gas reservoir classification;

[0109] c. Overlay analysis of reservoir parameters;

[0110] d. Establish a comprehensive evaluation index by integrating all hydrocarbon data;

[0111] e. Reservoir effectiveness classification, evaluation, and visualization.

[0112] Specifically, the data collection and preprocessing steps include:

[0113] Data from well logging, core sampling, and other sources from the target well are collected. Software is used to perform preliminary data processing to obtain reservoir parameters such as porosity, total organic carbon content, gas saturation, Poisson's ratio, volumetric compressibility, and Young's modulus. Poisson's ratio and volumetric compressibility are then normalized as needed to eliminate the influence of dimensions.

[0114] The steps for dividing the shale gas reservoir include:

[0115] Shale gas reservoirs are preliminarily classified based on conventional curves such as gamma curves, density curves, neutron curves, acoustic curves, and dual lateral curves, as well as unconventional curves such as electrical imaging and dipole acoustic waves, combined with calculated parameters such as porosity, gas saturation, and total organic carbon content.

[0116] The steps of the reservoir parameter overlay analysis include:

[0117] Based on the Poisson's ratio and volume compressibility coefficient curves after data collection and preprocessing, their dynamic changes are converted into overlapping characteristic curves to analyze the synergistic relationship between Poisson's ratio and volume compressibility coefficient.

[0118] The steps for establishing a comprehensive evaluation index by fusing all hydrocarbon data include:

[0119] Based on the total hydrocarbon values ​​collected and pretreated in the steps, and combined with Poisson's ratio and volume compressibility coefficient, a comprehensive evaluation index VI is established. The formula for VI is as follows:

[0120] VI=α(V norm +C b,norm )+β·TG norm

[0121] In the formula V norm C is the normalized Poisson's ratio. b,norm TG is the normalized volumetric compressibility factor. norm The normalized total hydrocarbon curve value is given, where α and β are weighting coefficients. To comprehensively reflect the rock's mechanical properties and gas content, the brittleness index and gas saturation are introduced to calculate the weighting coefficients, as shown in the following formula:

[0122]

[0123] β=1-α

[0124] In the formula, BI is the brittleness index, and S g The gas saturation level (BI) is calculated using the elastic parameters Young's modulus and Poisson's ratio, as shown in the following formula:

[0125]

[0126] In the formula, E is Young's modulus, E min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus, and V is Poisson's ratio. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0127] The steps for reservoir effectiveness grading evaluation and visualization include:

[0128] Based on the above-mentioned total hydrocarbon data, a comprehensive evaluation index VI was calculated and a cross plot was established using curves sensitive to reservoirs to determine the range of VI for different levels of shale gas reservoirs. The reservoirs in the step-by-step shale gas reservoirs were graded and evaluated, and finally, different colors were used to represent different levels for visualization on professional software.

[0129] In this embodiment, the "high brittleness-low compressibility" characteristics of the reservoir are quantitatively characterized by the overlapping area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. Combined with total hydrocarbon data, this directly reflects the degree of hydrocarbon enrichment, enabling accurate assessment of shale gas reservoir effectiveness. This addresses the inefficiency of shale gas reservoir effectiveness evaluation by establishing a comprehensive evaluation index using the overlapping characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values. Furthermore, the range of different comprehensive evaluation indices for different reservoirs is determined, allowing for rapid evaluation of reservoir effectiveness and improving the accuracy and efficiency of shale gas reservoir effectiveness assessment.

[0130] Example 3:

[0131] Another embodiment of this application relates to a method for evaluating the effectiveness of shale gas reservoirs based on the overlap characteristics of Poisson's ratio and volumetric compressibility coefficient and total hydrocarbon indication. The specific process can be as follows: Figure 2 As shown, it includes the following steps:

[0132] S1: Data collection and preprocessing.

[0133] Specifically, taking the Qiongzhusi Formation in the Yanjianwei Block of the Sichuan Basin as an example, during the drilling of the target shale gas well, the total hydrocarbon content in the drilling fluid was monitored in real time using equipment such as gas chromatographs, and the total hydrocarbon display data was recorded. After well completion, high-precision logging instruments such as dipole sonic logging tools and lithology density logging tools were used to obtain data on P-waves, S-waves, density, gamma, neutrons, and bilateral lateral waves of the shale formation.

[0134] The acquired P-wave, S-wave, density, gamma, neutron, and two-sided lateral data are imported into professional data processing software to calculate parameters such as Poisson's ratio, volume compressibility, porosity, gas saturation, permeability, and organic carbon content of the shale layer. The Poisson's ratio, volume compressibility, and total hydrocarbon data are then normalized according to a certain algorithm to ensure that the data range is between 0 and 1.

[0135] The normalization formula is as follows:

[0136]

[0137] In the formula y norm The curve is normalized, x min To find the minimum value of the curve that needs to be normalized, x max Let x be the maximum value of the curve to be normalized, and let x be the value of the curve to be normalized.

[0138] S2: Shale Gas Reservoir Classification

[0139] Specifically, based on the collected logging and well logging data, core data, and calculated porosity and total organic carbon (TOC) content, strata with TOC greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50% are preliminarily classified as shale gas reservoirs in this area.

[0140] S3: Reservoir Parameter Overlay Analysis

[0141] Specifically, the normalized Poisson's ratio and volumetric compressibility coefficient curves are displayed in the same curve track. The synergistic variation characteristics of the two curves are analyzed by overlay analysis. Combined with the total hydrocarbon curve, it is found that the Poisson's ratio decreases and the volumetric compressibility coefficient increases in the gas-bearing layer. Figure 3 As shown, the first channel is the depth curve, the second channel is the borehole diameter, uranium-free gamma and gamma curves, the third channel is the acoustic transit time, density and neutron curves, the fourth channel is the array induced resistivity curve, the fifth channel is the calculated organic carbon content, the sixth channel is Poisson's ratio, the seventh channel is Young's modulus, the eighth channel is the superposition analysis of Poisson's ratio and volume compression system, and the ninth channel is the interpretation conclusion. Figure 3 Analysis of the superimposed Poisson's ratio and volumetric compressibility revealed that: Type I reservoirs exhibit a large envelope area between Poisson's ratio and volumetric compressibility; Type II reservoirs exhibit a relatively large envelope area between Poisson's ratio and volumetric compressibility; and Type III reservoirs exhibit a small envelope area between Poisson's ratio and volumetric compressibility.

[0142] S4: Establish a comprehensive evaluation index by integrating all hydrocarbon data.

[0143] Based on the results of the superimposed analysis of reservoir parameters, and by incorporating the total hydrocarbon value, a comprehensive evaluation index VI for reservoir effectiveness is established. The formula for VI is as follows:

[0144] VI=α(V norm +C b,norm )+β·TG norm

[0145] In the formula V norm C is the normalized Poisson's ratio. b,norm TG is the normalized volumetric compressibility factor. norm The normalized total hydrocarbon curve value is given, where α and β are weighting coefficients. To comprehensively reflect the rock's mechanical properties and gas content, the brittleness index and gas saturation are introduced to calculate the weighting coefficients, as shown in the following formula:

[0146]

[0147] β=1-α

[0148] In the formula, BI is the brittleness index, and S g The gas saturation level (BI) is calculated using the elastic parameters Young's modulus and Poisson's ratio, as shown in the following formula:

[0149]

[0150] In the formula, E is Young's modulus, E min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus, and V is Poisson's ratio. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0151] The parameters in the above formula change dynamically with depth. The calculated BI for a certain depth point in this example well is 0.1598, α is 0.2564, β is 0.7436, and VI is 0.11435.

[0152] S5: Reservoir Effectiveness Grading Evaluation and Visualization

[0153] Specifically, using well data that has already undergone reservoir classification, cross plots are established by selecting the comprehensive evaluation index VI for different reservoir levels and sonic logging curves (AC) sensitive to reservoir conditions, such as... Figure 4 As shown in the diagram, the VI of the Class I shale gas reservoirs in this area is greater than 0.43, the VI of the Class II shale gas reservoirs is between 0.3 and 0.43, and the VI of the Class III shale gas reservoirs is less than 0.3. The effectiveness of adjacent well reservoirs can be accurately evaluated based on this range.

[0154] In this embodiment, the results obtained from a shale gas reservoir effectiveness evaluation method based on Poisson's ratio-volume compressibility coefficient overlap characteristics and total hydrocarbon indication are as follows: Figure 5 As shown in the figure, the first track is the depth curve, the second track is the wellbore diameter, uranium-free gamma and gamma curves, the third track is the sonic transit time, density and neutron curves, the fourth track is the array induced resistivity curve, the fifth track is the calculated organic carbon content, the sixth track is Poisson's ratio, the seventh track is Young's modulus, the eighth track is the superposition analysis of Poisson's ratio and volume compression system, the ninth track is the total hydrocarbon value, the tenth track is the comprehensive evaluation index VI calculated by this method, the eleventh track is the automatic rating of reservoir effectiveness by the magnitude of VI, and the twelfth track is the interpretation conclusion. It can be seen from the figure that the results of the automatic rating of shale gas reservoir effectiveness by this method have a high degree of consistency, and the method is accurate and feasible.

[0155] In this embodiment, three parameters—Poisson's ratio, volume compressibility coefficient, and total hydrocarbon indication—are combined to determine the gas content of shale from multiple perspectives, which can effectively improve the accuracy of the judgment. Moreover, this method is based on existing well logging and geological data, without the need for complex equipment and cumbersome procedures, and has high operability. This method is applicable to different types of shale gas reservoirs and has important guiding significance for shale gas exploration and development.

[0156] Example 4:

[0157] Another embodiment of this application relates to a shale gas reservoir effectiveness evaluation device. The implementation details of this shale gas reservoir effectiveness evaluation device are described below. The following details are for ease of understanding and are not essential for implementing this solution. A schematic diagram of the shale gas reservoir effectiveness evaluation device in this embodiment can be seen as follows: Figure 6 As shown, it includes an acquisition module 801, an envelope area determination module 802, a category determination module 803, a comprehensive evaluation index determination module 804, and an effectiveness evaluation module 805.

[0158] The acquisition module 801 is used to acquire the sonic logging curve data of the target well, the total hydrocarbon content value during the drilling process, and the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir.

[0159] The envelope area determination module 802 is used to construct Poisson's ratio curves and volumetric compressibility coefficient curves based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, and to superimpose the Poisson's ratio curves and volumetric compressibility coefficient curves on the same curve track to obtain the envelope area of ​​the Poisson's ratio curves and volumetric compressibility coefficient curves.

[0160] The category determination module 803 is used to determine the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve.

[0161] The comprehensive evaluation index determination module 804 is used to determine the comprehensive evaluation index of each shale gas reservoir based on the Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content corresponding to each shale gas reservoir.

[0162] The effectiveness evaluation module 805 is used to establish a cross plot with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis, and to evaluate the effectiveness of the shale gas reservoir based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0163] In some optional embodiments, a shale gas reservoir determination module is also included, which is used to obtain characteristic parameters of each shale segment of the target well, including porosity, organic carbon content, silica content and clay content.

[0164] Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

[0165] In some optional embodiments, the category determination module is further configured to determine that the shale gas reservoir with an envelope area greater than or equal to a first preset value is a type of shale gas reservoir;

[0166] And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir;

[0167] And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir;

[0168] The first preset value is greater than the second preset value.

[0169] In some optional embodiments, the calculation expression for the comprehensive evaluation index is as follows:

[0170] VI=α(V norm +C b,norm )+β·TG norm

[0171] Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

[0172] In some optional embodiments, the comprehensive evaluation index determination module is further configured to calculate the weighting coefficients in the comprehensive evaluation index based on the brittleness index and the gas saturation.

[0173] The weighting coefficient is calculated using the following expression:

[0174]

[0175] β=1-α

[0176]

[0177] Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0178] In some optional embodiments, the shale gas reservoir determination module is further configured to determine the shale segment that simultaneously satisfies the following conditions: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%, as the shale gas reservoir.

[0179] In some optional embodiments, the acquisition module is further configured to normalize the Poisson's ratio, volume compressibility factor, and total hydrocarbon content values.

[0180] In this embodiment, the "high brittleness-low compressibility" characteristic of the reservoir is quantitatively characterized by the overlapping area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. Combined with total hydrocarbon values, this directly reflects the degree of hydrocarbon enrichment. In other words, a comprehensive evaluation index is established using the overlapping characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values, to accurately determine the effectiveness of shale gas reservoirs. This addresses the inefficiency of shale gas reservoir effectiveness evaluation, defines the range of different comprehensive evaluation indices for different reservoirs, and enables rapid evaluation of reservoir effectiveness, thus improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation.

[0181] It is worth mentioning that all modules involved in this embodiment are logical modules. In practical applications, a logical unit can be a physical unit, a part of a physical unit, or a combination of multiple physical units. Furthermore, to highlight the innovative aspects of this application, this embodiment does not introduce units that are not closely related to solving the technical problems proposed in this application; however, this does not mean that other units are absent in this embodiment.

[0182] It should be noted that, in this disclosure, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element limited by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0183] Example 4:

[0184] Another embodiment of this application relates to an electronic device, such as... Figure 7 The device includes: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor to enable the at least one processor to perform the steps of the following method:

[0185] Acquire sonic logging curve data of the target well, total hydrocarbon content during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir;

[0186] Based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, a Poisson's ratio curve and a volumetric compressibility coefficient curve are constructed. The Poisson's ratio curve and the volumetric compressibility coefficient curve are superimposed on the same curve channel to obtain the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve.

[0187] The category of each shale gas reservoir is determined based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve.

[0188] The comprehensive evaluation index of each shale gas reservoir is determined based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content.

[0189] A cross plot is established with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis. The effectiveness of the shale gas reservoir is evaluated based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0190] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0191] The characteristic parameters of each shale stratum in the target well are obtained, including porosity, organic carbon content, silica content and clay content.

[0192] Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

[0193] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0194] Shale gas reservoirs whose envelope area is greater than or equal to a first preset value are classified as Class I shale gas reservoirs;

[0195] And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir;

[0196] And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir;

[0197] The first preset value is greater than the second preset value.

[0198] In one embodiment, the formula for calculating the comprehensive evaluation index is:

[0199] VI=α(V norm +C b,norm )+β·TG norm

[0200] Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

[0201] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0202] The weighting coefficients in the comprehensive evaluation index are calculated based on the brittleness index and gas saturation.

[0203] The weighting coefficient is calculated using the following expression:

[0204]

[0205] β=1-α

[0206]

[0207] Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0208] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0209] The shale layer that simultaneously meets the following criteria is identified as the shale gas reservoir: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%.

[0210] In one embodiment, the processor, when executing a computer program, also performs the following steps:

[0211] The Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content values ​​were normalized.

[0212] In this embodiment, the "high brittleness-low compressibility" characteristic of the reservoir is quantitatively characterized by the overlapping area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. Combined with total hydrocarbon values, this directly reflects the degree of hydrocarbon enrichment. In other words, a comprehensive evaluation index is established using the overlapping characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values, to accurately determine the effectiveness of shale gas reservoirs. This addresses the inefficiency of shale gas reservoir effectiveness evaluation, defines the range of different comprehensive evaluation indices for different reservoirs, and enables rapid evaluation of reservoir effectiveness, thus improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation.

[0213] The memory and processor are connected via a bus, which can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors and memories. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and will not be described further herein. The bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by the processor is transmitted over the wireless medium via an antenna, which further receives data and transmits it to the processor.

[0214] The processor manages the bus and general processing, and also provides various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory is used to store data used by the processor during operation.

[0215] The processor may include, but is not limited to, one or more processors or microprocessors. Each processor may be implemented as an 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 component, for executing the methods in the above embodiments.

[0216] Example 5:

[0217] Another embodiment of this application relates to a computer-readable storage medium storing a computer program. When executed by a processor, the computer program implements the steps of the following method:

[0218] Acquire sonic logging curve data of the target well, total hydrocarbon content during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir;

[0219] Based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, a Poisson's ratio curve and a volumetric compressibility coefficient curve are constructed. The Poisson's ratio curve and the volumetric compressibility coefficient curve are superimposed on the same curve channel to obtain the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve.

[0220] The category of each shale gas reservoir is determined based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve.

[0221] The comprehensive evaluation index of each shale gas reservoir is determined based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content.

[0222] A cross plot is established with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis. The effectiveness of the shale gas reservoir is evaluated based on the distribution of the shale gas reservoirs of various categories in the cross plot.

[0223] In one embodiment, when the computer program is executed by a processor, it further performs the following steps:

[0224] The characteristic parameters of each shale stratum in the target well are obtained, including porosity, organic carbon content, silica content and clay content.

[0225] Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

[0226] In one embodiment, when the computer program is executed by a processor, it further performs the following steps:

[0227] Shale gas reservoirs whose envelope area is greater than or equal to a first preset value are classified as Class I shale gas reservoirs;

[0228] And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir;

[0229] And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir;

[0230] The first preset value is greater than the second preset value.

[0231] In one embodiment, the formula for calculating the comprehensive evaluation index is:

[0232] VI=α(V norm +C b,norm )+β·TG norm

[0233] Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

[0234] In one embodiment, when the computer program is executed by a processor, it further performs the following steps:

[0235] The weighting coefficients in the comprehensive evaluation index are calculated based on the brittleness index and gas saturation.

[0236] The weighting coefficient is calculated using the following expression:

[0237]

[0238] β=1-α

[0239]

[0240] Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

[0241] In one embodiment, when the computer program is executed by a processor, it further performs the following steps:

[0242] The shale layer that simultaneously meets the following criteria is identified as the shale gas reservoir: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%.

[0243] In one embodiment, when the computer program is executed by a processor, it further performs the following steps:

[0244] The Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content values ​​were normalized.

[0245] In this embodiment, the "high brittleness-low compressibility" characteristic of the reservoir is quantitatively characterized by the overlapping area of ​​the normalized curves of Poisson's ratio and volumetric compressibility coefficient. Combined with total hydrocarbon values, this directly reflects the degree of hydrocarbon enrichment. In other words, a comprehensive evaluation index is established using the overlapping characteristics of Poisson's ratio and volumetric compressibility coefficient, along with total hydrocarbon values, to accurately determine the effectiveness of shale gas reservoirs. This addresses the inefficiency of shale gas reservoir effectiveness evaluation, defines the range of different comprehensive evaluation indices for different reservoirs, and enables rapid evaluation of reservoir effectiveness, thus improving the accuracy and efficiency of shale gas reservoir effectiveness evaluation.

[0246] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0247] Computer-readable storage media may also store at least one computer-executable program / instruction, such as computer-readable instructions. Computer-readable storage media include, but are not limited to, volatile memory and / or non-volatile memory. Volatile memory may include, for example, random access memory (RAM) and / or cache memory. Computer-readable storage media may include, for example, read-only memory (ROM), hard disk, flash memory, etc. For example, a non-transitory computer-readable storage medium may be connected to a computing device such as a computer, and then, when the computing device executes the computer-readable instructions stored on the computer-readable storage medium, the various methods described above can be performed.

[0248] In addition, the computer device may include (but is not limited to) a data bus, an input / output (I / O) bus, a display, and input / output devices (e.g., keyboard, mouse, speakers, etc.).

[0249] The processor can communicate with external devices via the I / O bus through wired or wireless networks.

[0250] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A method for evaluating the effectiveness of shale gas reservoirs, characterized in that, include: Acquire sonic logging curve data of the target well, total hydrocarbon content during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir; Based on the Poisson's ratio and volumetric compressibility coefficient of each shale gas reservoir, a Poisson's ratio curve and a volumetric compressibility coefficient curve are constructed. The Poisson's ratio curve and the volumetric compressibility coefficient curve are superimposed on the same curve channel to obtain the envelope area of ​​the Poisson's ratio curve and the volumetric compressibility coefficient curve. The category of each shale gas reservoir is determined based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve. The comprehensive evaluation index of each shale gas reservoir is determined based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content. A cross plot is established with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis. The effectiveness of the shale gas reservoir is evaluated based on the distribution of the shale gas reservoirs of various categories in the cross plot.

2. The shale gas reservoir effectiveness evaluation method according to claim 1, characterized in that, Before the steps of acquiring the sonic logging curve data of the target well, the total hydrocarbon content value during the drilling process, and the Poisson's ratio and volume compressibility of each shale gas reservoir, the following steps are also included: The characteristic parameters of each shale stratum in the target well are obtained, including porosity, organic carbon content, silica content and clay content. Shale gas reservoirs are determined based on a preset range of values ​​for the aforementioned characteristic parameters.

3. The shale gas reservoir effectiveness evaluation method according to claim 1, characterized in that, The step of determining the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve includes: Shale gas reservoirs whose envelope area is greater than or equal to a first preset value are classified as Class I shale gas reservoirs; And, the shale gas reservoir whose envelope area is greater than or equal to the second preset value and less than the first preset value is determined to be a Class II shale gas reservoir; And, the shale gas reservoir with an envelope area smaller than the second preset value is determined to be a Class III shale gas reservoir; The first preset value is greater than the second preset value.

4. The shale gas reservoir effectiveness evaluation method according to claim 1, characterized in that, The formula for calculating the comprehensive evaluation index is as follows: VI=α(V norm +C b,norm )+β·TG norm Wherein, VI is the comprehensive evaluation index, V norm For Poisson's ratio, C b,norm TG is the volume compressibility factor. norm The total hydrocarbon content is represented by α and β, which are weighting coefficients.

5. The shale gas reservoir effectiveness evaluation method according to claim 4, characterized in that, The step of determining the comprehensive evaluation index of each shale gas reservoir based on its Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content also includes: The weighting coefficients in the comprehensive evaluation index are calculated based on the brittleness index and gas saturation. The weighting coefficient is calculated using the following expression: β＝1-α Where α and β are weighting coefficients, BI is the fragility index, and S g E is the gas saturation, and E is Young's modulus. min E is the minimum value of Young's modulus. max V is the maximum value of Young's modulus. min V is the minimum value of Poisson's ratio. max This represents the maximum value of Poisson's ratio.

6. The shale gas reservoir effectiveness evaluation method according to claim 2, characterized in that, The step of determining shale gas reservoirs based on the preset numerical range of the characteristic parameters includes: The shale layer that simultaneously meets the following criteria is identified as the shale gas reservoir: organic carbon content greater than 0.2%, porosity greater than 1%, silica content greater than 60%, and clay content less than 50%.

7. The method for evaluating the effectiveness of shale gas reservoirs according to claim 1, characterized in that, The steps of obtaining sonic logging curve data of the target well, total hydrocarbon content values ​​during drilling, and Poisson's ratio and volume compressibility of each shale gas reservoir also include: The Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content values ​​were normalized.

8. A device for evaluating the effectiveness of shale gas reservoirs, characterized in that, include: The acquisition module is used to acquire sonic logging curve data of the target well, total hydrocarbon content values ​​during the drilling process, and Poisson's ratio and volume compressibility of each shale gas reservoir. The envelope area determination module is used to construct Poisson's ratio curves and volume compressibility coefficient curves based on the Poisson's ratio and volume compressibility coefficient of each shale gas reservoir, and to superimpose the Poisson's ratio curves and volume compressibility coefficient curves on the same curve track to obtain the envelope area of ​​the Poisson's ratio curves and volume compressibility coefficient curves. The category determination module is used to determine the category of each shale gas reservoir based on the envelope area of ​​the Poisson's ratio curve and the volume compressibility coefficient curve; The comprehensive evaluation index determination module is used to determine the comprehensive evaluation index of each shale gas reservoir based on the Poisson's ratio, volume compressibility coefficient, and total hydrocarbon content of each shale gas reservoir. The effectiveness evaluation module is used to establish a cross plot with the comprehensive evaluation index as the vertical axis and the sonic logging curve data as the horizontal axis, and to evaluate the effectiveness of the shale gas reservoir based on the distribution of the shale gas reservoirs of various categories in the cross plot.

9. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the shale gas reservoir effectiveness evaluation method as described in any one of claims 1 to 7.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the shale gas reservoir effectiveness evaluation method according to any one of claims 1 to 7.

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