A method for evaluating reservoir quality of a volcanic rock gas storage reservoir

Abstract

The application discloses a volcanic gas storage reservoir quality evaluation method, comprising: obtaining reservoir dynamic characteristics and reservoir static characteristics as reservoir evaluation; constructing a hierarchical structure model based on an analytic hierarchy process by using the reservoir dynamic characteristics and the reservoir static characteristics; constructing a judgment matrix according to the hierarchical structure model to obtain weight values ω of each evaluation index for the reservoir evaluation i ; comprehensively evaluating each evaluation index to obtain a quantitative score m i ; and calculating a volcanic gas storage evaluation index comprehensive value M according to the quantitative score m i in combination with the weight values ω i . The method solves the problem that current research on volcanic gas storage reservoir evaluation mainly focuses on static characteristics and does not involve dynamic characteristics.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of natural gas underground storage and gas reservoir engineering, and particularly relates to a volcanic rock gas storage reservoir quality dynamic evaluation method based on an analytic hierarchy process. BACKGROUND

[0002] The statements in this section merely provide background information related to the present disclosure and do not constitute prior art.

[0003] As a main tool for natural gas storage, peak shaving and supply guarantee, the natural gas underground gas storage is an important means to ensure the safety of national gas supply. As a geological body with reservoir and gas storage structure as the core, the most important thing for the construction success or failure is whether the reservoir can be injected, produced and stored.

[0004] In recent years, a large number of volcanic rock gas reservoirs have been discovered in Songliao Basin and Junggar Basin, etc. in China. The development and construction of volcanic rock gas storage require accurate evaluation of the reservoir quality under the dynamic injection and production of the gas storage. However, there is currently no reference example for the reconstruction of volcanic rock gas reservoirs for gas storage construction.

[0005] The complexity of volcanic rock geological characteristics and the uniqueness of dynamic injection and production of the gas storage lead to difficulties in understanding the static and dynamic characteristics of the reservoir in the construction of the volcanic rock gas storage. The reservoir characteristics of the volcanic rock gas reservoir are quite different from those of the ordinary sandstone and carbonate rock gas reservoir. The reservoir has various reservoir space types, serious heterogeneity, complex percolation characteristics, widely developed and unevenly distributed fractures and strong stress sensitivity of the reservoir rock. At the same time, in the dynamic production process of the gas storage, large flow, high speed and high strength injection and production are required in a short period, which brings great uncertainty to the evaluation of the reservoir of the volcanic rock gas reservoir reconstructed for gas storage.

[0006] The current research on the evaluation of the reservoir of the volcanic rock gas storage mainly focuses on the static characteristics, such as the geological characteristics of the gas reservoir, lithology and lithofacies, reservoir space characteristics and pore and fracture development characteristics, and does not pay attention to the dynamic constraint relationship between the reservoir and the alternating injection and production environment of the stratum, so it is difficult to determine the negative influence of various factors such as water invasion, stress sensitivity, rock and bound water deformation on the quality of the reservoir of the volcanic rock gas storage under the dynamic environment of the stratum.

[0007] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the present disclosure, and therefore can contain information that does not constitute prior art. SUMMARY

[0008] Therefore, the present disclosure provides a volcanic rock gas storage reservoir quality evaluation method, which solves the problem that the current research on the evaluation of the reservoir of the volcanic rock gas storage mainly focuses on the static characteristics and does not involve the dynamic characteristics.

[0009] To achieve the above-mentioned purposes, the reservoir quality evaluation method of the volcanic gas storage reservoir comprises the following steps.

[0010] Obtaining reservoir dynamic characteristics and reservoir static characteristics as reservoir evaluation, using the reservoir dynamic characteristics and the reservoir static characteristics to construct a hierarchical structure model based on an analytic hierarchy process;

[0011] According to the hierarchical structure model, a judgment matrix is constructed, and the weight value ω of each evaluation index for the reservoir evaluation is obtained i ;

[0012] Comprehensive evaluation is performed on each evaluation index to obtain a quantitative score m i ;

[0013] According to the quantitative score m i , combined with the weight value ω i , a volcanic gas storage evaluation index comprehensive value M is calculated.

[0014] In the present disclosure and possible embodiments, the reservoir static characteristics include reservoir macroscopic static characteristics and reservoir microscopic static characteristics;

[0015] The reservoir macroscopic static characteristics include water body characteristics, heterogeneity, effective thickness and reservoir permeation mode; the reservoir microscopic static characteristics include porosity, permeability and fracture development characteristics.

[0016] In the present disclosure and possible embodiments, the reservoir dynamic characteristics include fluid component characteristics, seepage characteristics and reservoir mechanical characteristics;

[0017] The fluid component characteristics include initial gas saturation, carbon dioxide content and natural gas relative density; the seepage characteristics include irreducible water saturation and pore space utilization efficiency; the reservoir mechanical characteristics include rock stress sensitivity and rock alternating fatigue characteristics.

[0018] In the present disclosure and possible embodiments, the construction method of the judgment matrix comprises:

[0019] According to the hierarchical structure model, through literature research, expert scoring and numerical simulation sensitivity analysis, each evaluation index is judged and compared, the relative importance degree of each evaluation index is obtained, and the judgment matrix is constructed by using a 1-9 scale method.

[0020] In the present disclosure and possible embodiments, the sum product method is used to calculate the maximum eigenvalue and the eigenvector of each judgment matrix, and consistency test is performed;

[0021] The weight value ω of each evaluation index is determined according to the maximum eigenvalue and the eigenvector of each judgment matrix i .

[0022] In the present disclosure and possible embodiments, a classification evaluation standard of the volcanic rock reservoir quality is obtained, and the comprehensive evaluation of each evaluation index is performed according to the classification evaluation standard, so as to obtain the quantitative score m i .

[0023] In the present disclosure and possible embodiments, the formula for the calculation is as follows:

[0024]

[0025] In the formula, m i is the quantitative score of each evaluation index; ω i is the weight value of each evaluation index; i = 1, 2, … n.

[0026] The present disclosure has the following beneficial effects:

[0027] The volcanic rock gas storage reservoir quality evaluation method based on the analytic hierarchy process provided by the present disclosure combines the evaluation standard established by the volcanic rock gas storage reservoir characteristics and the static and dynamic parameters of the built volcanic rock gas storage at home and abroad, uses five levels of the static macroscopic characteristics of the volcanic rock reservoir, the static microscopic characteristics of the reservoir, the fluid component characteristics, the fluid seepage characteristics and the reservoir mechanics characteristics to construct a volcanic rock gas storage reservoir evaluation model, determines the quantitative score and weight size of the dynamic and static evaluation indexes related to the reservoir quality, obtains the comprehensive value of the volcanic rock gas storage evaluation index, and realizes the quantitative evaluation of the volcanic rock gas storage reservoir quality. The method realizes the intuitive quantification of the static and dynamic evaluation standards, the result is reliable, the applicability is strong, and the method meets the reservoir evaluation requirements in the complex geological environment of the gas storage, and provides a reference for the subsequent injection and production operation and design optimization of the gas storage. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0029] Figure 1 is a flow chart of the volcanic rock gas storage reservoir quality evaluation method of the present disclosure;

[0030] Figure 2 is a hierarchical framework diagram of the volcanic rock gas storage reservoir quality evaluation of the present disclosure;

[0031] Figure 3 is a bar chart of the weight proportion of the volcanic rock gas storage reservoir evaluation index of the present disclosure;

[0032] Figure 4 is a curve of the water invasion replacement coefficient of the Shengping volcanic rock gas storage reservoir gas reservoir. DETAILED DESCRIPTION

[0033] The present disclosure is described below based on embodiments, but it is worth noting that the present disclosure is not limited to these embodiments. In the detailed description of the present disclosure below, some specific details are described in detail. However, for the parts not described in detail, those skilled in the art can also fully understand the present disclosure.

[0034] Furthermore, those skilled in the art should understand that the drawings are only provided to illustrate the purpose, features and advantages of the present disclosure, and are not actually drawn to scale.

[0035] At the same time, unless the context clearly requires otherwise, words such as "include", "comprising" and the like throughout the specification and claims should be interpreted as inclusive rather than exclusive or exhaustive; that is, as "including but not limited to".

[0036] The method of the present invention investigates a large number of volcanic gas reservoir parameters and domestic gas storage reservoir characteristics, focuses on the dynamic changes of reservoirs under the multi-cycle injection and production environment of gas storage, considers the static characteristics of the reservoir, rock mechanical characteristics, fluid seepage characteristics, formation water and gas storage injection and production operation parameters, adopts a dynamic and static combined analysis method to analyze the gas storage reservoir characteristics in a more comprehensive manner, and establishes a comprehensive evaluation method for the reservoir quality of volcanic gas storage. Specifically, the hierarchical analysis method combining qualitative and quantitative methods is adopted, and the 1-9 scaling method is used to comprehensively score the preferred evaluation indicators, obtain the relative importance ratios between the influencing factors of the same level, construct a judgment matrix, and obtain the maximum eigenvalue and its corresponding eigenvector. The eigenvector is the weight value ω of the evaluation indicator. i At the same time, a classification evaluation standard suitable for volcanic reservoir quality is established, and the evaluation standard is numerically quantified. With reference to the evaluation standard, a comprehensive evaluation of each evaluation index of the reservoir is performed to obtain the quantitative score m of each evaluation index. i ; Finally, according to the quantitative score m of each evaluation index i and weight value ω i The comprehensive value M of the volcanic gas storage evaluation index is obtained to achieve quantitative evaluation of the reservoir quality of the volcanic gas storage.

[0037] Figure 1 is a flow chart of a method for evaluating reservoir quality of a volcanic gas storage reservoir according to an embodiment of the present disclosure; Figure 1 As shown, the steps of the volcanic gas storage reservoir quality evaluation method are as follows:

[0038] Step S01: Establish a volcanic gas storage reservoir evaluation model based on the analytic hierarchy process:

[0039] A hierarchical system for evaluating the reservoir quality of volcanic gas storage is constructed using reservoir dynamic characteristics and reservoir static characteristics. Based on the characteristics of the dynamic operation process of volcanic gas storage, the disclosed embodiment specifically selects two reservoir static characteristics, namely, macroscopic reservoir static characteristics and microscopic reservoir static characteristics, and three reservoir dynamic characteristics, namely, fluid composition characteristics, fluid seepage characteristics, and reservoir rock mechanics characteristics. The hierarchical system is constructed from these five levels, where:

[0040] (1) Reservoir macroscopic static characteristics and reservoir microscopic static characteristics, mainly through the early geological data, well logging data and indoor test data of volcanic gas reservoirs to form a basic understanding of the reservoir static characteristics of volcanic gas reservoirs converted into gas storage facilities; among them, the reservoir macroscopic static characteristics include effective thickness, volcanic rock storage and permeability pattern, heterogeneity, and edge and bottom water characteristics; the reservoir microscopic static characteristics include porosity, permeability, and fracture development characteristics;

[0041] (2) Fluid component characteristics and fluid seepage characteristics. Fluid component characteristics are mainly obtained by chemical analysis of the fluid, including natural gas composition analysis (C1-C8, O2, N2, etc.), CO2 content analysis, natural gas relative density and other parameter analysis, specifically including initial gas saturation, carbon dioxide content and natural gas relative density; fluid seepage characteristics are mainly obtained by analyzing complex injection and production mechanisms such as gas-water multiphase seepage characteristics, reservoir production efficiency and gas-water migration during injection and production through indoor micro-storage and spatial production tests, etc., specifically including irreducible water saturation and pore space utilization efficiency;

[0042] (3) The basic understanding of reservoir rock mechanical characteristics is mainly obtained through rock multi-cycle stress sensitivity test and alternating mechanical fatigue test. The specific implementation standard is "Method for Determination of Rock Porosity and Permeability under Overburden Pressure".

[0043] (SY / T6385-1999), the stress sensitivity evaluation standard refers to SY / T5358-2010; for the reservoir rock mechanical characteristics, the rock stress sensitivity and rock alternating fatigue characteristics are specifically selected.

[0044] Based on the analytic hierarchy process, the above 14 characteristics are used as evaluation indicators to construct a hierarchical structure model for evaluating the reservoir quality of the volcanic gas storage reservoir in the embodiment of the present disclosure. Figure 2 As shown, A is the target layer, B1-B5 are the criterion layer, and C1-C14 are the solution layer; B1-B5 are the first-level indicators, and C1-C14 are the second-level indicators.

[0045] It should be noted that the evaluation index selection of the present step S01 is different for different research objectives, and different reservoir evaluation models can be constructed due to the differences in the specific geological characteristics of the volcanic gas storage reservoirs, but the method and idea of establishing the analytic hierarchy process framework model are the same.

[0046] Step S02: constructing a judgment matrix

[0047] First, the relative importance relationship between each factor is obtained through investigation of existing research results at home and abroad, expert scoring, numerical simulation sensitivity analysis and other means. Specifically, a 1-9 scale method is used to determine appropriate scales, as shown in Table 1: the scale value of the same importance is 1, the scale value of slightly important is 3, the scale value of relatively strong important is 5, the scale value of strong important is 7, the scale value of absolute important is 9, and 2, 4, 6 and 8 represent the intermediate values between the above two judgment levels.

[0048] Table 2 Classification standard of relative importance of factors

[0049] Value Explanation 1 A i With A j In comparison, both contribute equally to the target 3 A i With A j The former is slightly advantageous over the latter 5 A i With A j The former is more advantageous than the latter 7 <![CDATA[A i With A j Comparison shows that the former is more advantageous than the latter, and has obvious advantages.]]> 9 A i With A j The former is absolutely advantageous than the latter in comparison 2,4,6,8 The importance is between two adjacent values

[0050] Second, according to the determined scale value, the corresponding judgment matrix is constructed; the element value is a ij ·a jk =a ik , i, j, k = 1, 2, … n, a ii =1. According to the hierarchical structure model, each factor is judged and compared with each other to construct a judgment matrix, which can be expressed as follows.

[0051]

[0052] Step S03: calculating the eigenvalue and eigenvector, and performing consistency check

[0053] (1) Calculate the eigenvalue and eigenvector

[0054] The sum product method is used to calculate the maximum eigenvalue and eigenvector of the judgment matrix; the judgment matrix is normalized by column, b ij =a ij / ∑a ij , the normalized matrix is added by row, c i =∑b ij ; the column vector is normalized to obtain the eigenvector, and the maximum eigenvalue corresponding to the eigenvector is calculated. The eigenvector is the weight of each evaluation index.

[0055] (2) Consistency check

[0056] In order to test whether the weight coefficient is reasonably divided, the random consistency index is used. When the CR value is less than 0.1, it is judged that the matrix satisfies the consistency test, otherwise the matrix needs to be re-evaluated until a satisfactory consistency is obtained.

[0057] Step S04: determining the weight coefficient of each index

[0058] The evaluation index of the volcanic gas reservoir is sorted, and the weight value of each analysis item is obtained; specifically, after obtaining the relative importance between elements at the same level, the comprehensive importance of each level element to the overall is calculated. Among them, the weight of each secondary evaluation index relative to the target layer of the volcanic gas reservoir is the product of the weight of the secondary index relative to the primary index and the weight of the primary index relative to the target layer.

[0059] Step S05: establishing evaluation criteria and classifying and quantifying target reservoir evaluation indexes

[0060] Through the investigation of the volcanic gas reservoir parameters at home and abroad and the characteristics of the domestic gas storage reservoir, combined with the characteristics of the volcanic gas reservoir in China and the technical requirements of the gas storage development design, the classification evaluation standard suitable for the quality of the volcanic reservoir is established. The classification evaluation standard of the present embodiment is quantified as 10 points, 8 points, 6 points and 4 points respectively for excellent, good, medium and poor.

[0061] Referring to the classification evaluation standard, combined with the previous geological data, logging data, laboratory test data and numerical simulation results of the target volcanic gas storage reservoir, the comprehensive evaluation of each evaluation index is obtained. The quantized score m of each evaluation index is obtained. i .

[0062] Part of the classification evaluation standard is shown in Tables 3 and 4 as follows:

[0063] Table 3 Classification evaluation standard of Shengping volcanic gas storage (static)

[0064]

[0065]

[0066] Table 4 Classification evaluation standard of Shengping volcanic gas storage (dynamic)

[0067]

[0068] The inventors of the present application investigate a large number of volcanic gas storage reservoir related parameters and reservoir evaluation standards, laboratory test results, etc. The excellent, good, medium and poor of the domestic volcanic gas storage reservoir related parameters can be basically evaluated by referring to this standard.

[0069] Step S06: calculating the comprehensive value M of the quality index of the target gas storage reservoir

[0070] Quantitative score m of each evaluation index according to step S05 i The relative weight value ω of each evaluation index obtained by combining the analytic hierarchy process i The comprehensive value M of the evaluation index of the volcanic gas storage is calculated, and the quantitative evaluation of the volcanic gas storage is realized by referring to Table 5.

[0071] In the evaluation model, the calculation process of the comprehensive value M of the index is as follows:

[0072]

[0073] In the formula: m i is the quantitative score of each evaluation index; ω i is the weight value of each evaluation index relative to the volcanic reservoir; i = 1, 2, …, 13, 14.

[0074] Table 5 Classification standard for evaluation of volcanic gas storage index

[0075] Volcanic gas storage reservoir quality comprehensive score Index comprehensive value M Countermeasures and suggestions Best 9～10 Can be a good reservoir, gas storage capacity, operation capacity is good Suitable 8～9 Suitable for gas storage, operation capacity is relatively poor Basically suitable 6～8 The capacity is poor, and the reservoir needs to be transformed Not suitable ＜6 Not suitable for gas storage operation, it is difficult to reach the capacity

[0076] Embodiment

[0077] In this embodiment, the quality of the Shengping volcanic gas reservoir in Songliao Basin is evaluated.

[0078] The dynamic evaluation hierarchical structure model of the Shengping volcanic gas storage reservoir is shown in Figure 2 .

[0079] According to the classification evaluation standard in Table 3 and Table 4, the quality of each evaluation index of the Shengping volcanic gas storage reservoir is comprehensively evaluated, and the specific evaluation is as follows:

[0080] 1. Macroscopic static characteristics of the reservoir

[0081] 1.1 Permeation mode:

[0082] The Shengping volcanic gas storage has complex and diverse reservoir space types and complex structure, as shown in the following Table 6:

[0083] Table 6 Permeation mode of the Shengping volcanic gas storage

[0084]

[0085] According to Table 6 above, the Shengping gas storage reservoir is evaluated from the permeation mode. The reservoir space type is complex and diverse, mainly developed as pore type and fracture-pore type, and the comprehensive evaluation is “good”.

[0086] 1.2 Effective thickness:

[0087] The effective thickness of the volcanic rock is in the range of 50-130m, with an average effective thickness of 50.1m; the effective thickness >30m, and the comprehensive evaluation is "excellent".

[0088] 1.3 Heterogeneity:

[0089] The volcanic rock gas storage develops different types of reservoirs, with large differences in seepage capacity and large differences in planar distribution; vertically, the development depth of high-permeability reservoirs in different regions is distributed in a scattered manner, with local aggregation, and the heterogeneity is strong; from the evaluation of heterogeneity, the comprehensive evaluation of the Shengping gas storage reservoir is "poor".

[0090] 1.4 Water body characteristics:

[0091] According to the material balance model, the water invasion replacement coefficient of Shengping gas storage is 0.44, and the water invasion replacement coefficient of Shengping gas storage is 0.44, as shown in Figure 4 The movable edge-bottom water body is large, and at the initial stage of production, the gas well is prone to a large amount of water or water flooding, and the water invasion characteristic curve rises linearly in the stable production period of the gas reservoir.

[0092] Combined with the classification and evaluation criteria in Table 3, the comprehensive evaluation of the Shengping gas storage reservoir from the water body characteristics is "poor".

[0093] 2、Reservoir microstatic characteristics

[0094] 2.1 Porosity:

[0095] The porosity of the reservoir is between 4.0% and 27.5%, with an average of 8.4%;

[0096] 2.2 Permeability:

[0097] The permeability is between 0.006 and 319mD, with an average of 1.19mD;

[0098] 2.3 Fracture development degree:

[0099] Through imaging logging fracture parameter statistics (feasibility study report of Shengping gas storage in Daqing, evaluation of fracture development degree of deep volcanic gas reservoir), the average fracture density is 4.72 / m.

[0100] Combined with Table 3, the comprehensive evaluation of the Shengping gas storage reservoir from the microstatic characteristics of the reservoir is "medium" in porosity, "good" in permeability, and "medium" in fracture development degree.

[0101] 3、Fluid composition characteristics

[0102] The fluid composition characteristics of Shengping gas storage are shown in Table 7:

[0103] Table 7 Fluid composition characteristics of Shengping gas storage

[0104]

[0105]

[0106] The original gas saturation of the Shengping gas reservoir is 0.6, the original irreducible water saturation is 0.4, the methane content is between 91.43% and 96.22%, the carbon dioxide content is between 1.18% and 3.60%, and the relative density of the natural gas is between 0.58 and 0.61 (Feasibility of reconstructing an underground gas storage in a volcanic gas reservoir containing edge and bottom water).

[0107] According to the evaluation of the fluid component characteristics, the initial gas saturation of the Shengping gas reservoir is evaluated as "excellent", the carbon dioxide content is evaluated as "medium", and the relative density of the natural gas is evaluated as "excellent".

[0108] 4. Percolation characteristics

[0109] 4.1 Irreducible water saturation

[0110] In the previous core test analysis, 26 samples in the region were analyzed, and the irreducible water saturation was between 27.1% and 47.62%, with an average of 38.9%. After multiple rounds of gas-water mutual displacement phase permeability analysis, the irreducible water saturation of the rock samples after gas-water mutual displacement was between 40% and 80%.

[0111] 4.2 Pore space utilization efficiency

[0112] According to the results of the multi-cycle injection-production pore space mobilization test, after 6 cycles of injection-production, the pure gas zone space mobilization efficiency before the construction of the reservoir was 87.2%, the gas drive pure gas zone was 58.0%, and the gas-water transition zone was 37.6%.

[0113] According to the evaluation of the Shengping gas reservoir from the percolation characteristics level, the irreducible water saturation is evaluated as "poor", and the pore space utilization efficiency is evaluated as "poor".

[0114] 5. Reservoir mechanical characteristics

[0115] 5.5 Stress sensitivity

[0116] Through the reservoir rock stress sensitivity test, the results show that the stress sensitivity of different types of rocks is different, but for fractured core permeability damage rate, it is generally in the range of >70%, and for dense rock samples, the stress sensitivity is lighter and the damage degree is low. For safety considerations, the stress sensitivity of fractured rock samples is mainly considered.

[0117] 5.2 Rock alternating fatigue characteristics

[0118] Through the reservoir alternating mechanics fatigue test, the results show that the stability of the reservoir rock under alternating injection-production conditions is good, and no damage occurs, with a rating of "excellent".

[0119] In combination with Table 4, the reservoir of Shengping gas storage is evaluated from the reservoir mechanics characteristics. The stress sensitivity degree is strong, the damage rate is greater than 70%, and the comprehensive evaluation is "poor". Since no damage occurs, the stability is good, and the rock alternating mechanics comprehensive evaluation is "excellent".

[0120] According to literature research, expert scoring and numerical simulation method, the relative importance of each evaluation index is valued and the judgment matrix is constructed. The characteristic vector and weight calculation results of each evaluation index of the reservoir are shown in Table 8, which has passed the consistency test. The weight proportion of each evaluation index is determined as shown in Table 8. Figure 3

[0121] Table 8 Analytic hierarchy process characteristic vector and weight calculation results of each evaluation index

[0122]

[0123] According to the target gas storage geology, well logging data, indoor physical simulation experiment and numerical simulation results, the evaluation indexes of volcanic gas storage are formed. According to the classification evaluation standard of Table 3 and Table 4, the quantitative score m i of the 14 evaluation indexes in the optimal level framework is obtained, which is 6, 10, 4, 4, 6, 8, 4, 10, 6, 10, 6, 8, 4, 10, respectively.

[0124] According to the quantitative score m i of each evaluation index obtained above, combined with the weight value ω i of each evaluation index relative to the volcanic reservoir, the comprehensive index value M of the target volcanic gas storage reservoir is calculated as follows:

[0125]

[0126] According to Table 5, the comprehensive value of the volcanic gas storage reservoir in Songliao Basin belongs to the score range of 6-8, which is basically suitable for reconstruction of gas storage, but the capacity and production capacity are poor, and the reservoir needs to be reconstructed.

[0127] The evaluation results are consistent with the results of previous geological research and demonstration, and the results are reliable and applicable to actual engineering.

[0128] ​The above-described embodiments are merely illustrative of the implementation of the present disclosure, which are described in a more specific and detailed manner, but should not be understood as a limitation on the scope of the patent of the present disclosure. It should be noted that, for those skilled in the art, without departing from the concept of the present disclosure, a number of modifications, equivalent replacements, improvements, etc. can be made, which are all within the protection scope of the present disclosure. Therefore, the protection scope of the patent of the present disclosure should be subject to the appended claims.

Claims

1. A method for evaluating the reservoir quality of a volcanic gas storage reservoir, characterized in that: include: Acquiring reservoir dynamic characteristics and reservoir static characteristics for reservoir evaluation, and constructing a hierarchical structure model based on the hierarchical analysis method using the reservoir dynamic characteristics and the reservoir static characteristics; According to the hierarchical structure model, a judgment matrix is ​​constructed to obtain the weight value of each evaluation index used in the reservoir evaluation. ; Comprehensively evaluate each evaluation indicator to obtain its quantitative score ; According to the quantitative score , combined with the weight value , the comprehensive value of the evaluation index of volcanic gas storage is calculated M ; The reservoir static characteristics include macroscopic reservoir static characteristics and microscopic reservoir static characteristics; The macroscopic static characteristics of the reservoir include water body characteristics, heterogeneity, effective thickness and reservoir-permeability pattern; the microscopic static characteristics of the reservoir include porosity, permeability and fracture development characteristics; The reservoir dynamic characteristics include fluid composition characteristics, seepage characteristics and reservoir mechanical characteristics; The fluid component characteristics include initial gas saturation, carbon dioxide content and natural gas relative density; the seepage characteristics include irreducible water saturation and pore space utilization efficiency; The reservoir mechanical characteristics include rock stress sensitivity and rock alternating fatigue characteristics; The construction method of the judgment matrix includes: According to the hierarchical structure model, through literature research, expert scoring and numerical simulation sensitivity analysis, each evaluation indicator is judged and compared in pairs to obtain the relative importance of each evaluation indicator, and the judgment matrix is ​​constructed using the 1-9 scaling method; The maximum eigenvalue and eigenvector of each judgment matrix are calculated using the sum-product method, and consistency test is performed; Determine the weight value of each evaluation index based on the maximum eigenvalue and eigenvector of each judgment matrix .

2. The method for evaluating reservoir quality of a volcanic gas storage according to claim 1, wherein: Obtain the classification evaluation standard of volcanic rock reservoir quality, and perform the comprehensive evaluation on each evaluation index according to the classification evaluation standard to obtain the quantitative score .

3. The method for evaluating reservoir quality of volcanic gas storage according to claim 1 or 2, characterized in that: The formula for performing the calculation is: ； Where: is the quantitative score of each evaluation indicator; is the weight value of each evaluation index; i =1, 2,…n.

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