Carbonate buried hill reservoir gas storage reconstruction evaluation method and device

Abstract

The present application relates to a kind of carbonate buried hill oil reservoir reconstruction gas storage evaluation method and device, the method comprises: the cap rock sealing property and fault sealing property of carbonate buried hill oil reservoir are evaluated, and the trapping sealing property evaluation result is obtained;Attribute data body is obtained by multi-window dip scanning to time domain seismic data, and based on attribute data body, coherent attribute body, curvature attribute body and ant body attribute body are generated, and coherent attribute body, curvature attribute body are respectively fused with ant body attribute body, and the favorable reservoir characterization result is obtained;Reservoir space in the oil-gas-water three-phase saturation under the condition of reconstruction gas storage is calculated, and the capacity parameter evaluation result is obtained;Based on the trapping sealing property evaluation result, favorable reservoir characterization result and capacity parameter evaluation result, buried hill oil reservoir reconstruction gas storage evaluation result is generated.The present application method is suitable for the evaluation of reservoir type reconstruction gas storage, and provides good technical support for the design of gas storage scheme.

Description

Technical Field

[0001] The invention relates to a method and device for evaluating the reconstruction of a carbonate buried hill oil reservoir into a gas storage reservoir. Background Art

[0002] At present, the general technology for gas storage evaluation is the geological evaluation technology for gas reservoir-type gas storage construction, which is suitable for gas reservoir-type gas storage conversion. The evaluation requirements for gas reservoir closure sealing are low. The fluid seepage in the gas reservoir reservoir only involves two phases of gas and water, and the underground fluid seepage law is relatively simple. However, the fluid seepage in the oil reservoir reservoir is three-phase gas, oil and water. The evaluation method for gas reservoir-type gas storage conversion is not suitable for the evaluation of oil reservoir-type gas storage conversion. Summary of the Invention

[0003] In order to enrich the types of evaluation methods for converting carbonate buried-hill oil reservoirs into gas storage reservoirs in the existing technology, the present invention proposes a method and device for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage reservoirs. The technical solutions proposed in the present invention are as follows:

[0004] As a first aspect of the present invention, the present invention provides a method for evaluating the conversion of carbonate buried hill oil reservoirs into gas storage reservoirs, comprising:

[0005] Evaluate the caprock sealing and fault sealing properties of carbonate buried-hill reservoirs to obtain trap sealing evaluation results; the trap sealing evaluation results include surface attribute maps, isopach maps, and mudstone coefficient maps;

[0006] Scanning time-domain seismic data through multi-window dip angles to obtain an attribute data volume, generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result;

[0007] The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage are calculated under the condition of oil, gas and water three-phase saturation in the storage space, and the storage capacity parameter evaluation results are obtained;

[0008] Based on the trap sealing evaluation results, the favorable reservoir characterization results and the storage capacity parameter evaluation results, an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir is generated.

[0009] In some embodiments, the sealing performance of the caprock of a carbonate buried-hill reservoir is evaluated by:

[0010] Obtaining direct cover seismic waveforms, and analyzing the direct cover seismic waveforms using a pre-built waveform clustering model to form a surface attribute map; wherein the waveform clustering model is obtained by:

[0011] Selecting a preset number of traces of data from a target layer segment as a training sample set; wherein the target layer segment is a layer segment of uniform thickness, and the thickness of the target layer segment is greater than half a phase and less than 150ms;

[0012] Classify the training sample set according to different classification numbers to obtain at least two sample subsets, determine the sum of the intra-class distances of the at least two sample subsets under different classification numbers, and plot a graph of the change of the intra-class distances with the classification number;

[0013] Obtaining the number of classifications corresponding to the sum of the minimum intra-class distances from the change graph to obtain the target number of classifications;

[0014] The target classification number is used as the classification number of a pre-constructed BP neural network, and the BP neural network is trained based on the training sample set to obtain a waveform clustering model.

[0015] In some embodiments, the sealing performance of the caprock of a carbonate buried-hill reservoir is evaluated by:

[0016] Statistics were collected on the direct caprock encountered during drilling in buried-hill traps, and isopach maps and mudstone coefficient maps were drawn.

[0017] In some embodiments, the fault sealing performance of a carbonate buried-hill reservoir is evaluated by:

[0018] The trap formation-hydrocarbon generation-filling period is obtained, and the current activity and closure status of the fault is determined based on the trap formation-hydrocarbon generation-filling period.

[0019] In some embodiments, the fault sealing performance of a carbonate buried-hill reservoir is evaluated by:

[0020] Fault data of a carbonate buried-hill reservoir is obtained, and fault sealing parameters are determined based on the fault data; the fault sealing parameters include section pressure, sealing coefficient, and mudstone smear coefficient.

[0021] In some embodiments, the cross-sectional pressure is determined by the following formula:

[0022] P=D(ρ o -ρ w )cosα+σ1sinβsinα;

[0023] Where, P is the cross-sectional pressure; D is the vertical fault distance; ρ o is the oil density; ρ w is the water density; σ1 is the horizontal geostress; β is the angle between the horizontal geostress and the fault strike; α is the reservoir dip.

[0024] In some embodiments, the plugging coefficient includes a longitudinal plugging coefficient, a lateral plugging coefficient, a structural plugging coefficient, and a reservoir coefficient;

[0025] The longitudinal blocking coefficient is determined by the following formula:

[0026]

[0027] The lateral blocking coefficient is determined by the following formula:

[0028] F 横 =G·(C+R);

[0029] The structural blocking coefficient is determined by the following formula:

[0030]

[0031] The storage coefficient is determined by the following formula:

[0032]

[0033] Where R T is the longitudinal blocking coefficient; F 横 is the lateral plugging coefficient; C is the structural plugging coefficient; R is the reservoir coefficient; L is the vertical drop of the fault; H is the thickness of the cap rock; is the fault dip; α is the reservoir dip; K is the proportional coefficient; G is the lithologic sealing coefficient; and h is the reservoir cap thickness.

[0034] In some embodiments, the mudstone smear coefficient includes mudstone contamination potential, mudstone smear factor, and fault mudstone ratio; the mudstone contamination potential is determined by the following formula:

[0035]

[0036] The mudstone smear factor is determined by the following formula:

[0037]

[0038] The fault mudstone ratio is determined by the following formula:

[0039]

[0040] Where CSP is the mudstone contamination potential; SSF is the mudstone smear factor; SGR is the fault mudstone ratio; T i is the mudstone thickness of the ith mudstone segment; H i is the distance from a point on the i-th fault plane to the middle of the mudstone segment closest to the fault uplift wall; ΔZ i is the thickness of sandstone; V shi is the mud content of the i-th mudstone section;

[0041] Based on the mudstone smear potential, mudstone smear factor and fault mudstone ratio, a fault seal grade is determined.

[0042] In some embodiments, the method of obtaining an attribute data volume by scanning the time-domain seismic data through a multi-window dip angle scan, generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result includes:

[0043] The time domain seismic data is processed by multi-window dip scanning to obtain attribute data volume;

[0044] Taking the attribute data volume as the input of the seismic data volume, generating corresponding coherence attribute volume, curvature attribute volume and ant volume attribute volume;

[0045] The coherence attribute body and the curvature attribute body are fused with the ant body attribute body according to a preset ratio, and the fused bodies are compared to obtain a favorable reservoir characterization result.

[0046] In some embodiments, the storage capacity parameter includes an upper limit operating pressure and a lower limit operating pressure;

[0047] The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including:

[0048] The additional pressure on the artificial gas cap after gas injection at the top of the buried hill reservoir is determined by the following formula:

[0049] ΔP=(γ o -γ g -γ δ / B g )·ΔH·δ;

[0050] Where ΔP is the additional pressure; γ o is the formation crude oil weight ratio; γ g is the specific gravity of natural gas; γ δ is the air weight ratio; B g is the gas volume coefficient at the original formation pressure; ΔH is the gas cap height; δ is the unit conversion coefficient;

[0051] determining an upper limit operating pressure according to the additional pressure and the original formation pressure;

[0052] The lower limit operating pressure is determined based on the requirements for peak regulation and produced gas inlet station processing as well as the requirements for working gas volume.

[0053] In some embodiments, the storage capacity parameter includes storage capacity;

[0054] The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including:

[0055] The storage capacity of carbonate buried hill reservoirs is predicted by indoor physical simulation experiments and determined by the following formula:

[0056] Q g =V o ×S g ×η g / B g ;

[0057] Where Q g is the storage capacity; V o is the pore volume of the oil layer under original conditions; S g is the maximum gas saturation of gas drive; η g is the total swept volume coefficient of the gas; B g is the gas volume coefficient at the original formation pressure.

[0058] In some embodiments, the storage capacity parameter includes storage capacity; the storage capacity parameter is calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0059] The reservoir capacity of carbonate buried hill reservoir is predicted by fractured carbonate reservoir parameter prediction method. The following formula is used to determine the depth H of a gas-oil interface. g Under this condition, the storage capacity of the gas reservoir can be:

[0060] Q s (H g )=V(H g )×(Φ ∧ +Φ ΙΙ ) / B g (P av ,T av );

[0061] in,

[0062]

[0063] P i (H g )=aH g +b;

[0064] P top =P i (H g )e -s ;

[0065] S=0.03415γ g D 气 / (Z av T av );

[0066] V f (H g )=V(H g )×(Φ ^ +Φ ΙΙ ) / Φ ΙΙ ;

[0067] V w (H g )=V wo +V f (H g );

[0068] Where H g is the depth of a gas-oil interface; Q s (H g ) is the depth H at a certain gas-oil interface g Under this condition, the storage capacity of the gas reservoir can be achieved; V(H g ) is the gas-oil interface reaching a certain depth H g When , the volume of rock above this depth; Φ ∧ The porosity in the reservoir where only gas can invade the oil displacement reservoir space; Φ II B is the porosity of the reservoir space where both water and gas can drive oil; g (P av , T av ) is the gas volume coefficient at the average formation pressure and temperature of the gas reservoir; P sc is the pressure under standard conditions; T sc is the temperature under standard conditions; Z av is the average volume deviation coefficient of the gas column; T av is the average temperature of the air column; P av is the average formation pressure of the gas reservoir; P i (H g ) is the depth of a gas-oil interface H g The original formation pressure of the reservoir; P top is the pressure at the top of the gas column; γ g is the relative density of natural gas; D 气 is the height of the air column; V f (H g ) is the gas-oil interface reaching a certain depth H g When the oil-water interface moves, the rock volume swept by V w (H g ) is the rock volume above the oil-water interface; Vwo It is the rock volume above the oil-water interface before gas injection.

[0069] In some embodiments, the storage capacity parameter includes the working gas volume; the storage capacity parameter is calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0070] Use numerical simulation method to determine the flooding conditions at different working gas ratios, obtain the working gas ratio corresponding to the preset flooding conditions, and obtain the target working gas ratio;

[0071] The target working gas ratio is multiplied by the storage capacity to obtain the working gas volume.

[0072] In some embodiments, the storage capacity parameter includes cushion gas volume; the storage capacity parameter is calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0073] The dissolved gas ratio is obtained by performing an indoor core physical simulation gas injection experiment, and the supplementary cushion gas volume is obtained by multiplying the dissolved gas ratio by the residual oil volume;

[0074] The cushion gas volume is obtained by adding the supplementary cushion gas volume to the difference between the storage capacity and the working gas volume.

[0075] As a second aspect of the present invention, the present invention provides an evaluation device for converting a carbonate buried hill oil reservoir into a gas storage reservoir, comprising:

[0076] The trap sealing evaluation module is used to evaluate the caprock sealing and fault sealing properties of carbonate buried-hill reservoirs and obtain trap sealing evaluation results; the trap sealing evaluation results include surface attribute maps, isopach maps, and mudstone coefficient maps;

[0077] A favorable reservoir characterization module is used to obtain an attribute data volume by scanning the time domain seismic data with multiple windows and dip angles, generate a coherence attribute volume, a curvature attribute volume and an ant volume attribute volume based on the attribute data volume, and fuse the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result;

[0078] The storage capacity parameter evaluation module is used to calculate the storage capacity parameters of the carbonate buried hill reservoir under the condition of oil, gas and water three-phase saturation in the storage space after the reservoir is converted into a gas storage facility, and obtain the storage capacity parameter evaluation results;

[0079] A generation module is used to generate an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir based on the trap sealing evaluation result, the favorable reservoir characterization result and the storage capacity parameter evaluation result.

[0080] As a third aspect of the present invention, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage reservoirs as described in the first aspect.

[0081] As a fourth aspect of the present invention, the present invention provides an electronic device, comprising a processor, a communication interface, a memory, and a communication bus, wherein the processor, the communication interface, and the memory communicate with each other via the communication bus;

[0082] Memory for storing computer programs;

[0083] The processor is configured to implement the method for evaluating the conversion of carbonate buried hill reservoirs into gas storage facilities as described in the first aspect when executing the program stored in the memory.

[0084] Based on the above technical solution, the present invention has the following beneficial effects compared with the prior art:

[0085] The present invention provides a method for evaluating the reconstruction of carbonate buried-hill oil reservoirs into gas storage facilities, which respectively evaluates the caprock sealing property and fault sealing property of carbonate buried-hill oil reservoirs, obtains a trap sealing evaluation result, and forms a method for evaluating the trap sealing property of buried-hill oil reservoirs, overcomes the difficult problem of the complex formation of traps in carbonate buried-hill oil reservoirs, solves the problem of quantifying the trap sealing property, and makes the trap sealing property evaluation more reliable. The method obtains an attribute data body by multi-window dip scanning of time-domain seismic data, generates a coherent attribute body, a curvature attribute body, and an ant body attribute body based on the attribute data body, characterizes the lateral continuity of the reservoir by the coherent attribute body, characterizes the reservoir cracks by the curvature attribute body, characterizes the linear structural characteristics of the fault by the ant attribute body, and then fuses the coherent attribute body and the curvature attribute body with the ant body attribute body to obtain a favorable reservoir characterization result, thereby solving the problems of the distribution characteristics of the dominant lithofacies of the reservoir and the prediction of cracks. It makes high-precision dual-medium modeling possible, laying the foundation for subsequent numerical simulation and scheme design; the storage capacity parameters of the reservoir space under the condition of oil, gas and water three-phase saturation after the carbonate buried-hill oil reservoir is converted into a gas storage are calculated, and the storage capacity parameter evaluation results are obtained, forming a storage capacity parameter evaluation method that conforms to the complex geological characteristics of the buried-hill oil reservoir, solving the problem of storage capacity calculation under the condition of oil, gas and water three-phase saturation after the carbonate buried-hill oil reservoir is converted into a gas storage, making the storage capacity parameter evaluation more scientific and reasonable; then, based on the closure sealing evaluation results, favorable reservoir characterization results and storage capacity parameter evaluation results, the evaluation results of the buried-hill oil reservoir converted into a gas storage are generated, forming an evaluation method for the carbonate buried-hill oil reservoir converted into a gas storage, which fills the technical gap. Compared with general technologies, this method is more targeted and suitable for the evaluation of reservoir-type converted gas storage, providing good technical guarantee for the design of storage schemes.

[0086] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purposes and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0087] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0088] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0089] Figure 1 It is a flow chart of the evaluation technology for converting gas reservoir into gas storage;

[0090] Figure 2 This is a flow chart of the evaluation technology for converting carbonate buried hill reservoirs into gas storage;

[0091] Figure 3 This is a flow chart of the evaluation method for converting carbonate buried hill reservoirs into gas storage;

[0092] Figure 4 This is a flow chart of the comprehensive evaluation technology for trap sealing of carbonate buried-hill reservoirs;

[0093] Figure 5 This is a schematic diagram of the weathering crust structure at the top of the buried hill;

[0094] Figure 6 This is a schematic diagram of the cap rock of the buried hill trap;

[0095] Figure 7 This is the mudstone coefficient map of the 5m formation above the buried hill top;

[0096] Figure 8 This is a map of the thickness of mudstone in the 5m formation above the buried hill top;

[0097] Figure 9 This is the waveform clustering reservoir prediction map of the direct caprock of the buried hill;

[0098] Figure 10 It is a schematic diagram of the BP neural network structure;

[0099] Figure 11 It is a cross-section of the development history of buried hill structures;

[0100] Figure 12This is a diagram of the hydrocarbon generation evolution history of the depression;

[0101] Figure 13a It is the stress analysis diagram of the fault plane (section);

[0102] Figure 13b It is the force analysis diagram of the fault plane (plane view);

[0103] Figure 14 It is a schematic diagram of the trap parameters of fault-block reservoirs;

[0104] Figure 15 This is a schematic diagram of the calculation model for the lateral sealing property value of the fault;

[0105] Figure 16 This is a structural map of a buried mountain top;

[0106] Figure 17 This is the reservoir cross section of wells 357-437-358-440;

[0107] Figure 18 This is the gas injection and effect curve of the 437 well area;

[0108] Figure 19 This is a technical flow chart for comprehensive reservoir evaluation of carbonate buried hill reservoirs;

[0109] Figure 20 This is a schematic diagram of the most coherent reflector dip discrete scan;

[0110] Figure 21 It is a schematic diagram of the 2D curvature calculation model;

[0111] Figure 22a This is the operation process of the ant body attribute module Figure 1 ;

[0112] Figure 22b This is the operation process of the ant body attribute module Figure 2 ;

[0113] Figure 23 It is a schematic diagram of attribute ratio fusion;

[0114] Figure 24 This is a flow chart for evaluating storage capacity parameters of carbonate buried hill reservoirs;

[0115] Figure 25 This is a flow chart for calculating the storage capacity of carbonate buried hill reservoirs;

[0116] Figure 26 This is a diagram of water flooding conditions at different working gas volumes in carbonate buried-hill reservoirs;

[0117] Figure 27 This is a diagram of dissolved gas loss at different gas injection rates;

[0118] Figure 28 This is a schematic diagram of the structure of the evaluation device for converting carbonate buried hill reservoirs into gas storage;

[0119] Figure 29 It is a structural diagram of an electronic device. DETAILED DESCRIPTION

[0120] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0121] Exemplary embodiments will be described in detail herein, examples of which are illustrated in the accompanying drawings. In the following description, when referring to the drawings, like numbers in different figures represent like or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0122] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0123] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0124] The current general technology is the geological evaluation technology for gas reservoir type gas storage. Its technical process refers to Figure 1The method involves five aspects: trap sealing evaluation (including caprock sealing evaluation, fault sealing evaluation, and site stability evaluation), comprehensive reservoir evaluation (including reservoir sedimentary characteristics evaluation, reservoir physical property evaluation, and reservoir seepage characteristics evaluation), old well assessment (including well condition, wellbore analysis, and casing wear and tear cementing quality evaluation), gas reservoir description (including gas reservoir characteristics, 3D geological modeling, and detailed calculation of gas reservoir reserves), and storage capacity parameter evaluation (including gas reservoir development characteristics analysis, operating pressure design, and storage capacity parameter evaluation).

[0125] General technology itself is suitable for converting gas reservoirs into gas storage facilities. The evaluation requirements for gas reservoir trap tightness are low, and fluid flow in gas reservoir formations involves only two phases: gas and water. The patterns of underground fluid flow are relatively simple. However, the inventors discovered that fluid flow in oil reservoir formations involves three phases: gas, oil, and water. General technology is inadequate for comprehensive evaluation of carbonate buried-hill reservoir conversions into gas storage facilities. This involves determining the tightness of injected natural gas within the buried-hill reservoir traps. Furthermore, gas reservoir capacity evaluation methods are unsuitable for addressing the complex issues of buried-hill reservoir construction evaluation, due to the complex reservoir structure, varying underground fluids, operating pressures, and development methods. This approach falls short of the inventors' expectations. Further research and development led to the present invention.

[0126] The purpose of the present invention is, firstly, to make up for the deficiencies of existing general technologies, solve technical problems such as the difficulty in evaluating the sealing performance of carbonate buried-hill oil reservoirs, the operating pressure design under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage, and the calculation of storage capacity parameters, and improve the reservoir prediction method for fracture evaluation in reservoir evaluation; secondly, to achieve technical protection for the entire process of comprehensive evaluation of carbonate buried-hill oil reservoirs converted into gas storages, the key of which is the sealing performance evaluation method of carbonate buried-hill oil reservoirs converted into gas storages, the seismic attribute characterization method of favorable reservoirs in reservoir evaluation, and the storage capacity parameter evaluation method.

[0127] Example 1

[0128] The embodiment of the present invention provides a method for evaluating the reconstruction of carbonate buried hill oil reservoir into gas storage reservoir, referring to Figure 2 and Figure 3 Shown, including:

[0129] S101, evaluating the caprock sealing properties and fault sealing properties of the carbonate buried-hill reservoir to obtain a trap sealing evaluation result; the trap sealing evaluation result includes a surface attribute map, an isopach map, and a mudstone coefficient map;

[0130] S102, scanning the time-domain seismic data through a multi-window dip angle scan to obtain an attribute data volume, generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result;

[0131] S103, calculating storage capacity parameters of the carbonate buried hill reservoir after it is converted into a gas storage facility under the condition of oil, gas and water three-phase saturation in the storage space, and obtaining storage capacity parameter evaluation results;

[0132] S104: Based on the trap sealing evaluation result, the favorable reservoir characterization result and the storage capacity parameter evaluation result, generate an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir.

[0133] The embodiment of the present invention provides an evaluation method for converting carbonate buried-hill oil reservoirs into gas storage reservoirs, which evaluates the caprock sealing and fault sealing properties of carbonate buried-hill oil reservoirs respectively, obtains a trap sealing evaluation result, and forms a trap sealing evaluation method for buried-hill oil reservoirs, overcomes the complex problem of the formation of traps in carbonate buried-hill oil reservoirs, solves the problem of quantifying the trap sealing, and makes the trap sealing evaluation more reliable; time-domain seismic data are scanned by multiple windows at an angle to obtain an attribute data body, and a coherent attribute body, a curvature attribute body and an ant body attribute body are generated based on the attribute data body, and the lateral continuity of the reservoir is characterized by the coherent attribute body, the reservoir cracks are characterized by the curvature attribute body, and the linear structural characteristics of the faults are characterized by the ant attribute body, and then the coherent attribute body and the curvature attribute body are respectively fused with the ant body attribute body to obtain a favorable reservoir characterization result, which solves the problems of the distribution characteristics of the dominant lithofacies of the reservoir and the prediction of cracks. , making high-precision dual-medium modeling possible, laying the foundation for subsequent numerical simulation and scheme design; the storage capacity parameters of the reservoir space under the condition of oil, gas and water three-phase saturation after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir are calculated, and the storage capacity parameter evaluation results are obtained, forming a storage capacity parameter evaluation method that conforms to the complex geological characteristics of the buried-hill oil reservoir, solving the problem of storage capacity calculation under the condition of oil, gas and water three-phase saturation in the reservoir space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, making the storage capacity parameter evaluation more scientific and reasonable; then based on the closure sealing evaluation results, favorable reservoir characterization results and storage capacity parameter evaluation results, the evaluation results of the buried-hill oil reservoir converted into a gas storage reservoir are generated, forming an evaluation method for the carbonate buried-hill oil reservoir converted into a gas storage reservoir, this method fills the technical gap, and compared with general technologies, this method is more targeted and suitable for the evaluation of reservoir-type converted gas storage, providing a good technical guarantee for the design of storage schemes.

[0134] The technical solution of the present invention (refer to Figure 2 shown) and the general technical solution (refer to Figure 1Compared with the existing technology (shown in the original), the present invention establishes a comprehensive evaluation technology system centered on trap sealing evaluation, comprehensive reservoir evaluation, and reservoir capacity parameter evaluation. Specifically, the site stability evaluation within the trap sealing evaluation, the reservoir sedimentary characteristics evaluation, reservoir physical property evaluation, and reservoir seepage characteristics evaluation within the comprehensive reservoir evaluation, the assessment of old wells (including well condition, wellbore analysis, and cementing quality evaluation for casing wear and tear), the reservoir description (including reservoir characteristics, 3D geological modeling, and detailed calculation of reservoir reserves), and the analysis of reservoir development characteristics within the reservoir capacity parameter evaluation are all mature technologies. Those skilled in the art can refer to the specific descriptions in the prior art and will not be elaborated here.

[0135] The first part of this embodiment describes a method for evaluating the sealing performance of carbonate buried-hill reservoir traps:

[0136] Reference Figure 4 As shown, the evaluation of the sealing performance of carbonate buried-hill reservoirs includes four aspects: caprock sealing performance evaluation, fault sealing performance evaluation, field testing, and site stability evaluation. Caprock sealing performance evaluation includes caprock petrological characteristics, caprock physical properties, genetic analysis, indirect caprock distribution characterization, and direct caprock distribution characterization. Fault sealing performance evaluation includes fault geometry, fault kinematic characteristics, fault genetic mechanism, tectonic evolution-reservoir analysis, and qualitative and quantitative fault sealing performance evaluation. Field testing includes nitrogen injection field testing. Site stability evaluation includes tectonic movement evaluation, regional seismic characteristics evaluation, and surface geological hazard evaluation. This invention provides technical innovations in the direct caprock genesis, direct caprock distribution characteristics, quantitative fault sealing performance evaluation, and field testing of carbonate buried-hill traps.

[0137] The evaluation of the sealing property of the caprock includes the analysis of the formation mechanism of the caprock of the buried hill trap. Regarding the analysis of the formation mechanism of the caprock of the buried hill trap: In the past, it was believed that the upper cover layer of sandstone and mudstone overlapped the top of the buried hill, and the sealing capacity of the caprock was questionable. Based on the "ternary structure" theory of the weathering crust, this paper proposes for the first time that the completely weathered residual material in the upper part of the weathering crust is relatively stable in both horizontal and vertical distribution, and its lithology is mudstone, which has the sealing capacity to become the direct caprock of the trap. Figure 5 The following is a schematic diagram of the weathering crust structure at the top of the buried hill, including completely weathered rocks, rocks weathered into small stones over a long period of time, slightly weathered rocks, and unweathered rocks. The weathering crust at the top of the buried hill includes completely weathered residual materials (compacted and consolidated by burial, dense, and with good sealing properties, covering the top of the buried hill), strongly weathered zones (referring to long-term weathering, dolomite "sandification", sandstone, conglomerate), moderately weathered zones, slightly weathered zones, and unweathered zones. Figure 5The middle arrow indicates that there are weathered materials and unweathered core rocks in the weathering crust at the top of the buried hill, and spherical weathering occurs along the joints. During the research and practice of reconstructing a gas storage reservoir in a buried hill, the inventors of this invention found that there is a continuous and widely distributed phase axis with a negative phase weak reflection on the Tg reflection axis of the top of a buried hill. After well seismic and stratigraphic comparison, the upper part of the weathering crust is a set of purple-red and brown-red mudstones with a thickness of 2-10m and a stable distribution throughout the area (refer to Figure 6 As shown, the arrow points to the part).

[0138] In a specific embodiment, the sealing performance of the caprock of a carbonate buried hill reservoir is evaluated by the following method:

[0139] Statistics on the direct caprock encountered by drilling wells in buried hill traps, and draw isopach maps (refer to Figure 7 shown) and mudstone coefficient diagram (refer to Figure 8 Those skilled in the art may refer to the specific description in the prior art for the specific method of drawing, which will not be described here in detail.

[0140] The evaluation of caprock sealing performance includes direct caprock distribution characterization. Direct caprock distribution characterization can also use reservoir prediction waveform clustering method. First, analyze the seismic waveform of direct caprock to find out the overall law of waveform change. Use BP neural network technology to classify the waveform to form a reference. Figure 9 The surface attribute map shown can reflect the changes in lithology and thickness of the direct cover rock.

[0141] Waveform clustering uses neural network technology to classify seismic waveforms (spectra). Waveform clustering can be used for seismic phase analysis and lithofacies analysis. Seismic phase analysis involves analyzing and identifying seismic phase units based on seismic attributes. Overall changes in seismic waveforms are closely related to changes in lithology and lithofacies. Any changes in physical parameters unrelated to seismic wave propagation are reflected in seismic waveforms. Therefore, seismic waveform changes can be analyzed. By effectively classifying seismic waveforms, the overall patterns of waveform change can be identified, thereby understanding the patterns of seismic phase change.

[0142] During the learning phase, the neural network learns from training samples selected from the target segment of the seismic data. Through multiple iterations, it constructs model traces and creates a metric representing waveform differences within the seismic segment. During the classification phase, the actual seismic traces are compared with the model traces, and the model trace that most closely resembles the actual trace is assigned a sequence number.

[0143] Reference Figure 10As shown, it is a structural schematic diagram of the BP neural network, and the basic idea of the BP neural network algorithm is that the learning process is composed of two processes of forward propagation and backward propagation. When forward propagation, the input sample is processed layer by layer through the input layer to the output layer; if the actual output of the output layer does not match the expected output, the error backward propagation stage is entered. The error backward propagation is to transmit the output error to the input layer through the hidden layer in a certain form, and the error is allocated to all units of each layer, so as to obtain the error signal of each unit, which is used as the basis for correcting the weight of each unit.

[0144] The conventional waveform clustering method is suitable for equal-thickness layer sections, and the time-frequency domain waveform clustering method is suitable for equal-thickness and unequal-thickness layer sections. The actual process of obtaining samples for training includes selecting a layer section, selecting training data, setting the number of classifications and quality control of the number of classifications.

[0145] In a specific embodiment, the sealing property of the cap rock of the carbonate buried hill reservoir is evaluated by the following method:

[0146] The direct cap rock seismic waveform is obtained, the waveform clustering model is constructed in advance, the direct cap rock seismic waveform is analyzed, and the surface attribute map is formed (see Figure 9 After obtaining the surface attribute map, the Geoeast software can be used to smooth the parameters of the surface attribute map. Figure 9 In the figure, the dark area is mudstone, and the light area is carbonate rock.

[0147] The waveform clustering model is obtained by the following method:

[0148] S1011, selecting a preset number of data in a target layer section as a training sample set; wherein the target layer section is an equal-thickness layer section, and the thickness of the target layer section is greater than half a phase and less than 150ms;

[0149] In the process of selecting the target layer section, the waveform features are selected, and the equal-thickness layer section is selected. The thickness of the layer section is greater than half a phase and less than 150ms. If the thickness of the layer section is too large, too many models are included, which brings difficulties to interpretation, and the physical meaning is also not clear. When selecting the amount of data used for training the BP neural network samples, for a small three-dimensional survey area, such as less than 300×300 channels, each channel of data can be used; for a larger survey area, for example, 1000×1000 channels, in order to reduce the calculation time, one channel is extracted from every four channels as the training data of the BP neural network, thereby obtaining the training sample set. If the interval between adjacent training data is too large, such as more than 10×10, some important features will be ignored.

[0150] S1012, classifying the training sample set according to different classification numbers to obtain at least two sample subsets, determining the sum of the intra-class distances of the at least two sample subsets under different classification numbers, and plotting a graph showing changes in the intra-class distances versus the classification number;

[0151] S1013. Obtain the number of categories corresponding to the sum of the minimum intra-category distances from the change graph to obtain the target number of categories;

[0152] The correct number of classifications should depend on the target to be studied and the degree of understanding of the data. A large number of classifications will result in too detailed results, while a small number of classifications will result in too rough results. More than 15-20 categories are usually difficult to interpret. In practical applications, the appropriate number of classifications is determined based on the complexity of the seismic signal, the size of the layer segment, and the degree of understanding of the seismic data. Generally, the number of classifications is between 5 and 15. The embodiment of the present invention determines the target number of classifications through quality control of the number of classifications. The specific process is as follows: let the number of classifications range from 2 to M, classify the training sample set according to each classification number, obtain several sample subsets, and calculate the sum of the intra-class spacing of each subset under each classification number, as shown in the following formula. Draw a quality control chart of the number of classifications, that is, a chart showing the change of intra-class spacing with the number of classifications, find the appropriate number of classifications from the change chart (the optimal number of classifications is the minimum ERR), and complete the waveform clustering chart.

[0153]

[0154]

[0155] Where: ERR K It represents the sum of the intra-class distances when the number of classifications is , represents the jth training sample in the i-th sample subset; w(i) represents the weight of the i-th category, n(i) represents the number of training samples in the i-th sample subset; K represents the number of categories, and N represents the total number of training samples.

[0156] S1014: Using the target number of classifications as the number of classifications of a pre-built BP neural network, training the BP neural network based on the training sample set to obtain a waveform clustering model.

[0157] After obtaining the target number of classifications, the target number of classifications is set as the number of classifications for the BP neural network classifier. The training sample set is input into the BP neural network. If the actual output of the output layer does not match the expected output (i.e., the true classification result), the output error is determined based on the actual output and the true classification result, and the error backpropagation phase is entered. The output error is propagated back layer by layer through the hidden layer to the input layer, and the output error is apportioned to all units in each layer to obtain an error signal for each unit in each layer. This error signal serves as the basis for correcting the weights of each unit until the output error is less than the preset error threshold. At this point, training is completed and a trained waveform clustering model is obtained.

[0158] Fault sealing evaluation includes fault sealing structural evolution-reservoir analysis. In a specific embodiment, the fault sealing of carbonate buried hill reservoirs is evaluated by the following method:

[0159] The trap formation-hydrocarbon generation-filling period is obtained, and the current activity and closure status of the fault is determined based on the trap formation-hydrocarbon generation-filling period.

[0160] Taking the structural evolution and reservoir formation analysis of a buried hill as an example, refer to Figure 11 and Figure 12 As shown, fault activity was most intense during the Paleogene Shahejie Formation deposition period. Fault activity ceased with trap formation at the end of Dongying Formation deposition, and after the Quaternary, the fault closed, preserving the reservoir at deep burial. In the figure, Pt represents the Proterozoic, Chg represents the Gaoyuezhuang Formation, Jxw represents the Wumishan Formation, Es3 represents the third member of the Shahejie Formation, Es2 represents the second member of the Shahejie Formation, Es1 represents the first member of the Shahejie Formation, Es2+3 represents the second and third members of the Shahejie Formation, Ed represents the Dongying Formation, Q represents the Quaternary, N represents the late Tertiary, Ng represents the Guantao Formation, and Nm represents the Minghuazhen Formation.

[0161] Fault sealing evaluation includes quantitative evaluation of fault sealing. This embodiment quantifies fault sealing by cross-sectional pressure, sealing coefficient, and mudstone smear coefficient. In a specific embodiment, the fault sealing of a carbonate buried-hill reservoir is quantitatively evaluated by the following method:

[0162] Fault data of a carbonate buried-hill reservoir is obtained, and fault sealing parameters are determined based on the fault data; the fault sealing parameters include section pressure, sealing coefficient, and mudstone smear coefficient.

[0163] In a specific embodiment, Figure 13a and Figure 13b is a force analysis diagram of the fault surface, and the cross-sectional pressure is determined by the following formula:

[0164] P=P1+P2=D(ρ o -ρ w )cosα+σ1sinβsinα;

[0165] Where, P is the cross-sectional pressure; P1 is the first pressure; P2 is the second pressure; D is the vertical fault distance; ρ o is the oil density; ρ w is the water density; σ1 is the horizontal geostress; β is the angle between the horizontal geostress and the fault strike; α is the reservoir dip.

[0166] In a specific embodiment, Figure 14 This is a schematic diagram of fault block reservoir trap parameters. Figure 14 As shown, the plugging coefficient includes the longitudinal plugging coefficient, the lateral plugging coefficient, the structural plugging coefficient and the storage coefficient;

[0167] The longitudinal blocking coefficient R T Determined by the following formula:

[0168]

[0169] Lateral blocking coefficient F 横 It is an important parameter to evaluate whether the fault plane can seal the oil and gas in two plates. The lateral sealing coefficient F 横 Determined by the following formula:

[0170] F 横 =G·(C+R);

[0171] The structural blocking coefficient C reflects the blocking probability, and is determined by the following formula:

[0172]

[0173] The reservoir coefficient R reflects the amount of oil and gas blocked in the reservoir. The reservoir coefficient R is determined by the following formula:

[0174]

[0175] Where R T is the longitudinal blocking coefficient; F 横 is the lateral plugging coefficient; C is the structural plugging coefficient; R is the reservoir coefficient; L is the vertical drop of the fault; H is the thickness of the cap rock; is the fault dip; α is the reservoir dip; K is the proportional coefficient; G is the lithologic sealing coefficient; and h is the reservoir cap thickness. G ranges from 1 to 0. When the sealing layer is mudstone, G is 1; when it is sandy mudstone, G is 0.75; when it is argillaceous sandstone, G is 0.5; and when pure sandstone is not a sealing layer, G is 0.

[0176] The amount of mudstone smear is mainly related to the mudstone thickness and the distance between the mudstone and the study point. The amount of mudstone smear at any point is the sum of the smear amounts provided by all mudstone layers passing through that point. The parameters used to evaluate the sealing of a point on the fault plane are the mudstone contamination potential CSP, the mudstone smear factor SSF and the fault mudstone ratio SGR. The calculation model is based on Figure 15 shown.

[0177] In a specific embodiment, the mudstone smear coefficient includes mudstone contamination potential CSP, mudstone smear factor SSF and fault mudstone ratio SGR;

[0178] The mudstone contamination potential CSP is determined by the following formula:

[0179]

[0180] The mudstone smearing factor SSF is determined by the following formula:

[0181]

[0182] The fault mudstone ratio SGR is determined by the following formula:

[0183]

[0184] In the formula, CSP is the mudstone contamination potential; SSF is the mudstone smearing factor; SGR is the fault mudstone ratio; T i is the mudstone thickness of the ith mudstone section; H i is the distance from a point on the ith fault surface to the middle of the nearest mudstone section of the upthrown wall; ΔZ i is the sandstone thickness; V shi is the argillaceous content of the ith mudstone section;

[0185] Based on the mudstone contamination potential, the mudstone smearing factor and the fault mudstone ratio, the fault sealing grade is determined;

[0186] After calculating the quantitative indicators of the fault sealing, the comparison results with the fault surface mud smearing evaluation and the fault lateral sealing coefficient as shown in Table 1 are determined to determine the fault sealing grade.

[0187]

[0188] Table 1

[0189] The present application first forms a buried hill reservoir trap sealing evaluation method, overcomes the complex problem of carbonate buried hill reservoir trap genesis, solves the problem of sealing quantification, and makes the sealing evaluation more reliable.

[0190] The carbonate buried hill reservoir trap sealing evaluation also includes field tests, and the specific process is: a nitrogen injection gravity drive test is designed, and whether there is gas leakage is verified by observing the surrounding production wells and the oil production effect. Taking the nitrogen injection gravity drive test of a buried hill reservoir from 2018 to 2021 as an example, Figure 16 is a buried hill top surface structure, Figure 17 is a reservoir profile of well 357-437-358-440, well 437 (mountain depth 2974m) is designed to inject gas, and well 257 (mountain depth 2974.5m) is designed to produce oil.

[0191] The maximum daily injection of well 437 is 36,000 cubic meters, and the gas injection horizon is the fourth oil group of mist. Referring to Figure 18 , it is the gas injection and response curve of well 437 area.

[0192] First round of gas injection: 2020.10.15-2021.2.10, cumulative injection of nitrogen is 204x104m 3The average daily injection volume is 1.7×104m 3 , oil pressure 23MPa, oil increase 303t.

[0193] Second round of gas injection: nitrogen injection from April 10, 2021 to May 11, 2021, with a cumulative injection volume of 84×104m 3 , average daily injection volume 3×104m 3 , oil pressure 29MPa, oil increase 381t.

[0194] The effectiveness of nitrogen gravity flooding in this test well group demonstrates that the injected nitrogen did not escape, but instead accumulated within the internal reservoir space of the buried-hill trap, displacing oil and water. Because a fault extending from the caprock to the interior of the buried-hill exists between the test well groups, the test results confirm three aspects: first, the buried-hill caprock has a strong sealing capacity, preventing nitrogen from escaping from the caprock; second, the fault in the caprock above the buried-hill has a strong sealing capacity, not affecting the sealability of the caprock; and third, the internal fault does not serve to block oil and gas.

[0195] The second part of this embodiment describes the comprehensive evaluation of carbonate buried hill reservoirs:

[0196] Reference Figure 19 As shown, comprehensive reservoir evaluation of carbonate buried-hill reservoirs includes evaluation of reservoir sedimentary characteristics, reservoir physical properties, reservoir seepage characteristics, and favorable reservoir characterization. Reservoir sedimentary characteristics evaluation (including sedimentary environment, reservoir distribution characteristics, reservoir connectivity, petrological characteristics, diagenetic stage, reservoir space characteristics, and pore structure characteristics), reservoir physical property evaluation (including well logging interpretation and core testing), and reservoir seepage characteristics evaluation (including phase permeability experimental analysis, outflow sensitivity analysis, and oil and production testing) are all mature technologies. Those skilled in the art can refer to the detailed descriptions in the prior art and will not be repeated here. The present invention incorporates the following technical innovations in favorable reservoir characterization of carbonate buried-hill reservoirs.

[0197] Changes in seismic event waveforms are more sensitive to large and medium-sized fractures. The embodiment of the present invention uses a multi-window scanning-coherence volume-curvature-ant volume optimization fusion seismic prediction technology method to form a seismic attribute characterization technology for favorable carbonate buried-hill reservoirs.

[0198] About multi-window tilt scanning:

[0199] Under normal circumstances, since it is impossible to obtain an accurate time-depth conversion relationship, the dip and azimuth bodies only reflect the relative change relationship between the dip and azimuth. However, with the development of algorithms, it is now possible to calculate the dip and azimuth of the reflection layer of three-dimensional seismic data without picking up the layer, so that the estimation of dip and azimuth using vertical windows is more stable than the estimation based on layer data. It can identify and describe faults, river channels, and predict carbonate reservoirs. The embodiment of the present invention obtains the window with the greatest similarity through multi-window scanning (refer to Figure 20 The corresponding inclination and azimuth are used as the inclination and azimuth of the current analysis point, which improves the calculation accuracy of the inclination and azimuth. Figure 20 As shown, the test results show that the minimum tilt angle is -20°, the maximum tilt angle is +20°, and the tilt angle corresponding to the maximum coherence value is +5°. In this embodiment, the tilt angle (+5°) corresponding to the window with the greatest similarity, that is, the maximum coherence value, is used as the tilt angle of the current analysis point.

[0200] About Coherent:

[0201] Discontinuities in strata can lead to a decrease in the similarity of seismic reflection waveforms. The coherence attribute calculates the correlation between non-adjacent seismic data within a given time window, reflecting the lateral continuity of the strata through the similarity of the seismic waveforms. This is a seismic attribute used to detect faults and lithologic boundaries.

[0202] The principle of the coherence algorithm is to reflect the discontinuity of the event axis by calculating the cross-correlation function of adjacent seismic traces through the cross-correlation theory. The calculation formula of the coherence value C1 along the apparent dip angle (p, q) is as follows:

[0203]

[0204] Where C ij (i = 1, 2) is the cross-correlation between traces i and j, m; the apparent dip angles (p, q) are the time shifts between the seismic traces in the x and y directions, m, respectively. The apparent dip angles (p, q) are the dip angles corresponding to the window with the greatest similarity determined by the multi-window scan.

[0205] About curvature:

[0206] Curvature is the degree of curvature of any point on a curve. It is the inverse of the radius of a circle. Its size can reflect the curvature of an arc. The greater the curvature, the more curved it is. For brittle rocks, the degree of crack development is proportional to the degree of curvature. The embodiment of the present invention uses the curvature method to evaluate cracks. For reservoirs such as caves, reefs and river channels, which will cause the bending of seismic phase axes or the change of amplitude energy, they can also be characterized by curvature. Figure 21 As shown, the 2D curvature estimation formula is as follows:

[0207]

[0208] Anticline k 2D >0 (positive curvature), level k 2D = 0 (zero curvature), syncline k 2D <0 (negative curvature).

[0209] About Ant Body:

[0210] The ant tracking method is a fault identification method based on the ant colony algorithm. It simulates the position of ants and sets ant crawling routes in different directions. When there are abnormalities such as faults in the geological body, the ants will track along the fault abnormal body until they stop tracking the fault geological body. The ant tracking idea refers to Figure 22a and Figure 22b As shown, an initialization algorithm is used to adjust and determine the tracking control strategy, expand the search points, perform fault tracking, and use this as a clue to update pheromones. The initialization algorithm includes the initial ant distribution and ant tracking direction estimation; tracking strategy control includes tracking step length control, tracking abnormal step control, tracking normal step control, and tracking allowable deviation control. The specific ant tracking process involves inputting coherence attribute volume or variance type data; calculating the coherence attribute volume using the ant tracking algorithm to form a fault information attribute volume (i.e., ant attribute volume); tracking the cross section using the fault automatic tracking algorithm; editing the tracked cross section in three-dimensional space, calculating the cross section position on the cross section, and displaying it on the cross section. The ant volume highlights the linear structural features of the fault and removes information unrelated to the fault in the coherence or variance cross section. This embodiment of the present invention utilizes the ant tracking method disclosed in patent application publication number CN 114488297A, entitled "A Fault Identification Method and Apparatus," to achieve fault tracking. The specific tracking process can be referenced in the specific implementation described in that patent and will not be further described here.

[0211] After obtaining the coherence attribute body, curvature attribute body and ant body attribute body, refer to Figure 23 As shown in the figure, they are fused according to a preset ratio, achieving a proportional fusion of the two seismic attribute data volumes. Generally, background data, such as the curvature attribute volume, is used as background data A, and attribute data reflecting geological features such as faults, or the coherence attribute volume, is used as feature data B. A and B are fused according to a preset ratio. The fused output data C contains key information from both the curvature attribute volume and the coherence attribute volume, making it easier for interpreters to compare the two data volumes, thereby reducing the uncertainty of interpreting a single data volume.

[0212] In a specific embodiment, the above-mentioned step S102 is performed by scanning the time domain seismic data through a multi-window dip angle to obtain an attribute data volume, generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result, including:

[0213] S1021. Processing the time-domain seismic data through multi-window dip scanning to obtain an attribute data volume;

[0214] S1022, using the above attribute data volume as the input of the seismic data volume to generate corresponding coherence attribute volume, curvature attribute volume and ant volume attribute volume;

[0215] The above attribute data volume is input into GeoEast, and the coherence, curvature and ant body attribute volume generation modules of GeoEast are used to generate the corresponding coherence attribute volume, curvature attribute volume and ant body attribute volume.

[0216] S1023: Fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume according to a preset ratio to obtain a fused volume, and comparing the obtained fused volumes to obtain a favorable reservoir characterization result.

[0217] The above preset ratios can be set according to actual needs. In the embodiment of the present invention, 75% of the curvature attribute body and 25% of the coherence attribute body are respectively fused with the ant attribute body to obtain a fused body. After obtaining the fused body, the fused body is compared with the reservoir parameters of different regions obtained by drilling to determine the value range of the favorable buried-hill reservoir reflected in the fused body. Similarly, the distribution of favorable buried-hill reservoirs in the well-free area of ​​the fused body is obtained.

[0218] Since carbonate buried-hill reservoirs are different from sandstone reservoirs and have a dual-pore structure, divided into fracture and rock block systems, with large differences in physical properties and strong heterogeneity, the present invention improves the carbonate reservoir evaluation method. Through the multi-window scanning-coherence volume-curvature-ant volume optimization fusion seismic prediction method, a seismic attribute characterization method for favorable carbonate buried-hill reservoirs is successfully formed, which solves the problems of reservoir dominant lithofacies distribution characteristics and fracture prediction, makes high-precision dual-medium modeling possible, and lays the foundation for subsequent numerical simulation and scheme design.

[0219] The third part of this embodiment describes the evaluation of storage capacity parameters of carbonate buried hill reservoirs:

[0220] Reference Figure 24As shown, reservoir description (including oil-gas-water interface analysis, 3D geological modeling, and detailed reserve calculation) is a mature technology. Storage capacity parameter evaluation includes reservoir development characteristic analysis, operating pressure design, and storage capacity parameter calculation. Reservoir development characteristic analysis is a mature technology, and those skilled in the art can refer to the detailed description in the prior art, which will not be repeated here. In terms of storage capacity parameter evaluation (storage capacity parameters include storage capacity, working gas volume, cushion gas volume, and supplemental cushion gas volume), the present invention makes the following technical innovations in operating pressure, storage capacity calculation, working gas volume, and cushion gas volume calculation.

[0221] About operating pressure design:

[0222] The upper operating pressure limit should be designed to ensure the sealing of the gas storage geology and generally not exceed the original formation pressure. The upper operating pressure limit for a gas storage facility converted from a buried-hill reservoir should be the difference between the original formation pressure and the additional pressure. After gas injection at the top of a buried-hill reservoir forms an artificial gas cap, the static gas column pressure in the gas cap is lower than the original static oil column pressure because the density of the formation gas in the gas cap is lower than that of the oil. Therefore, the gas cap experiences an additional pressure.

[0223] In a specific embodiment, the storage capacity parameter includes an upper limit operating pressure and a lower limit operating pressure;

[0224] The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including:

[0225] The additional pressure on the artificial gas cap after gas injection at the top of the buried hill reservoir is determined by the following formula:

[0226] ΔP=(γ o -γ g -γ δ / B g )·ΔH·δ;

[0227] Where ΔP is the additional pressure; γ o is the formation crude oil weight ratio; γ g is the specific gravity of natural gas; γ δ is the air weight ratio; B g is the gas volume coefficient at the original formation pressure; ΔH is the gas cap height; δ is the unit conversion coefficient;

[0228] determining an upper limit operating pressure according to the additional pressure and the original formation pressure;

[0229] For example, after the gas storage facility was built, a maximum gas column of 430 m was formed. Based on formation oil-gas density difference data, the additional pressure difference at this point was calculated to be 1.99 MPa. For safety reasons, the caprock pressure was maintained below the original formation pressure of 32.6 MPa, and the recommended upper operating pressure for the buried-hill gas storage facility was 30.6 MPa.

[0230] The lower operating pressure limit must meet the requirements for external transmission and working gas volume. External transmission requirements refer to maintaining high production capacity at low gas well pressure, meeting peak shaving and gas inbound processing requirements. This means maintaining high production capacity at low gas well pressure and maintaining a minimum wellhead external transmission pressure above 12 MPa. Working gas volume requirements refer to meeting storage capacity utilization requirements and being able to produce a high working gas volume (for specific working gas volume determination, see the Working Gas Volume Calculation section below).

[0231] The lower limit operating pressure is determined based on the requirements for peak shaving, produced gas inlet processing, and working gas volume. For example, for a buried hill reservoir with a 50% working gas ratio, the lower limit operating pressure of the gas storage is 18 MPa.

[0232] About library capacity calculation:

[0233] Reference Figure 25 As shown, the embodiment of the present invention calculates reservoir capacity using multiple methods, including a fractured carbonate reservoir parameter prediction method, a numerical simulation prediction method, and an empirical indoor physical simulation experiment method. These methods are then cross-validated to obtain a relatively reasonable reservoir capacity range. In this case, the reservoir capacity calculation method that best matches the complex geological characteristics of the buried-hill reservoir is selected to obtain the final reservoir capacity parameter value. The empirical indoor physical simulation experiment method is suitable for situations with limited data, low development levels, and limited dynamic and static data; the numerical simulation prediction method is suitable for situations with high development levels and abundant dynamic and static data; and the fractured carbonate reservoir parameter prediction method is suitable for situations where the study area has undergone large-scale nitrogen injection testing and has acquired abundant data.

[0234] Indoor physical simulation experiment empirical method is based on existing knowledge and uses oil and gas reservoir engineering methods to calculate and determine the reservoir capacity through indoor physical simulation experiments. In a specific embodiment, the reservoir capacity parameters include reservoir capacity;

[0235] The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including:

[0236] The storage capacity of carbonate buried hill reservoirs is predicted by indoor physical simulation experiments and determined by the following formula:

[0237] Q g =V o ×S g ×η g / Bg ;

[0238] Where Q g is the storage capacity; V o is the pore volume of the oil layer under original conditions, 10 8 m 3 ;S g is the maximum gas saturation of gas drive, %; η g is the total swept volume coefficient of the gas, %; B g is the gas volume coefficient at the original formation pressure.

[0239] The numerical simulation prediction method builds a numerical simulation model of the gas injection and production process in carbonate buried-hill reservoirs. It simulates the gas, oil, and water distribution at the end of injection, and outputs the natural gas reserves, or reservoir capacity. For details, please refer to the numerical simulation modeling method described in patent application number 202210155788.8, entitled "A Step-by-Step Optimization Method for Injection and Production Parameters in Gas Drive Reservoirs."

[0240] The fractured carbonate reservoir parameter prediction method is based on current knowledge, utilizing reservoir engineering and three porosity analogy methods. Key empirical values ​​obtained from a nitrogen injection test in a buried-hill reservoir are used. The calculation method is as follows.

[0241] The internal reservoir space of buried hill oil and gas reservoirs is simplified into three categories

[0242] Ⅰ: The space in the reservoir where only gas can invade to drive oil, called the upper space, represented by ∧;

[0243] II: The space in the reservoir where only water can invade to drive oil, called the lower space, represented by ∨;

[0244] III: The space in the reservoir where both water and gas can drive oil, represented by ∥.

[0245] Three types of porosity are calculated based on the experience of a certain buried hill:

[0246] Water flooding porosity (including type II and III spaces) is water flooding porosity (∨ + ∥) = cumulative oil production / water-flooded rock volume × 100% = 1.056%

[0247] Gas drive porosity (including type I and III spaces) is gas drive porosity (∧+∥) = cumulative gas injection volume / gas drive rock volume × 100% = 0.8734%

[0248] The porosity that can be swept by both water and gas (Type III reservoir space) is the porosity that can be swept by both water and gas (∥) = cumulative gas displacement / increased rock volume in the oil zone after gas injection × 100% = 0.4899%

[0249] The empirical values ​​of the three types of reservoir space of this buried hill reservoir are: ∨ = 0.5661%, ∥ = 0.4899%, ∧ = 0.3834%

[0250] Taking this buried hill as an example, similar analogy shows that the water flooding porosity of the first and second buried hills is 108.9%, and the water flooding porosity of the third buried hill is 43%.

[0251] Further calculations show that the three types of reservoir spaces in the first and second buried hills are: ∨ = 0.5661% × 1.089 ≈ 0.62%, ∥ = 0.4899% × 1.089 ≈ 0.53%, and ∧ = 0.3834% × 1.089 ≈ 0.42%.

[0252] The three types of reservoir spaces in the third buried hill are: ∨ = 0.5661% × 0.43 ≈ 0.24%, ∥ = 0.4899% × 0.43 ≈ 0.21%, and ∧ = 0.3834% × 0.43 ≈ 0.16%.

[0253] The total reservoir space (∨+∥+∧) of the first and second buried hills is 1.57%, of which the gas drive porosity (∧+∥) of the first and second buried hills is 0.95%. The total reservoir space (∨+∥+∧) of the third buried hill is 0.62%, of which the gas drive porosity (∧+∥) of the third buried hill is 0.37%.

[0254] After obtaining key parameters such as total reservoir space and gas drive porosity, the reservoir capacity is calculated using the three-type porosity method. The specific process is as follows:

[0255] In a specific embodiment, the storage capacity parameter includes storage capacity; the storage capacity parameter is calculated in the above step S103 under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0256] The reservoir capacity of carbonate buried hill reservoir is predicted by fractured carbonate reservoir parameter prediction method. The following formula is used to determine the depth H of a gas-oil interface. g Under this condition, the storage capacity of the gas reservoir can be:

[0257] Q s (H g )=V(H g )×(Φ ∧ +Φ ΙΙ ) / B g (P av ,T av );

[0258] in,

[0259] Since the bottom water is very large, the depth of the gas-oil interface is H gThe lower formation pressure is basically the same as the original reservoir pressure system. The original reservoir formation pressure is:

[0260] P i (H g )=aH g +b;

[0261] Pressure at the top of the gas column P top Calculated according to the static air column pressure distribution formula:

[0262] P top =P i (H g )e -s ;

[0263] S=0.03415γ g D 气 / (Z av T av );

[0264] Average formation pressure P of gas reservoir av The calculation formula is:

[0265]

[0266] The gas-oil interface reaches a certain depth H g When the oil-water interface moves, the rock volume V swept by f (H g )Calculation formula:

[0267] V f (H g )=V(H g )×(Φ ∧ +Φ ΙΙ ) / Φ ΙΙ ;

[0268] The volume of rock above the oil-water interface V w (H g ) is calculated as:

[0269] V w (H g )=V wo +V f (H g );

[0270] Where H g is the depth of a gas-oil interface, m; Q s (H g ) is the depth H at a gas-oil interface g Under this condition, the gas storage capacity that can be achieved; V(H g ) is the gas-oil interface reaching a certain depth H gWhen the rock volume above the depth is m 3 Φ ∧ The porosity in the reservoir where only gas can invade the oil displacement reservoir space; Φ II B is the porosity of the reservoir space where both water and gas can drive oil; g (P av , T av ) is the gas volume coefficient at the average formation pressure and temperature of the gas reservoir; P sc is the pressure under standard conditions, MPa; T sc is the temperature under standard conditions, K; Z av is the average volume deviation coefficient of the gas column; T av is the average temperature of the air column; P av is the average formation pressure of the gas reservoir, MPa; P i (H g ) is the depth of a gas-oil interface H g Original formation pressure of the reservoir, MPa; P top is the pressure at the top of the gas column, MPa; γ g is the relative density of natural gas; D 气 is the height of the air column, m; V f (H g ) is the gas-oil interface reaching a certain depth H g When the oil-water interface moves, the rock volume, m 3 ; V w (H g ) is the rock volume above the oil-water interface, m 3 ; V wo is the rock volume above the oil-water interface before gas injection, m 3 .

[0271] During the top gas drive process, the oil-water interface was pushed to the overflow point of 3495m, and the maximum storage capacity of the first and second buried hills was 6.51 billion cubic meters, and the maximum storage capacity of the third buried hill was 1.311 billion cubic meters.

[0272] About the calculation of working gas volume:

[0273] The numerical simulation method is used to compare the flooding of injection and production gas wells at different working gas ratios. When the working gas ratio is greater than a certain percentage, the water cone intensifies and the injection and production gas wells are flooded. Then the working gas volume obtained by multiplying the working gas ratio and the reservoir capacity reaches the maximum value.

[0274] In a specific embodiment, the storage capacity parameter includes the working gas volume; the storage capacity parameter is calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried hill reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0275] Use numerical simulation method to determine the flooding conditions at different working gas ratios, obtain the working gas ratio corresponding to the preset flooding conditions, and obtain the target working gas ratio;

[0276] Reference Figure 26 As shown, when the working gas ratio is greater than 70%, the water cone intensifies and the injection and production gas well is flooded. This working gas ratio is used as the target working gas ratio. Figure 26 In the figure, the dark areas are water, the gray areas are oil, and the dark gray areas are gas.

[0277] The target working gas ratio is multiplied by the storage capacity to obtain the working gas volume.

[0278] About the calculation of cushion air volume and supplementary cushion air volume:

[0279] The solubility of natural gas in oil is much greater than that in water. The present invention uses indoor core physical simulation gas injection experiments to obtain reference Figure 27 The dissolved gas loss diagram of the gas injection rate is shown. The maximum dissolved gas ratio and the minimum dissolved gas ratio corresponding to the designed operating gas injection rate of the gas storage are read from the dissolved gas loss diagram. The average of the maximum dissolved gas ratio and the minimum dissolved gas ratio is calculated. The average is multiplied by the residual oil volume to obtain the supplementary cushion gas volume. The difference between the storage capacity and the working gas volume plus the supplementary cushion gas volume is the most reasonable cushion gas volume.

[0280] In a specific embodiment, the storage capacity parameter includes cushion gas volume; the storage capacity parameter is calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation result is obtained, including:

[0281] The dissolved gas ratio is obtained by performing an indoor core physical simulation gas injection experiment, and the supplementary cushion gas volume is obtained by multiplying the dissolved gas ratio by the residual oil volume;

[0282] The cushion gas volume is obtained by adding the supplementary cushion gas volume to the difference between the storage capacity and the working gas volume.

[0283] The present invention forms for the first time a storage capacity parameter evaluation method that conforms to the complex geological characteristics of buried-hill oil reservoirs, solves the problem of storage capacity calculation under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried-hill oil reservoir is converted into a gas storage reservoir, and makes the storage capacity parameter evaluation more scientific and reasonable; compared with existing general technologies, this technology is more targeted, and it is the first time to study the evaluation technology for converting carbonate buried-hill oil reservoirs into gas storage reservoirs. There is no precedent for converting carbonate buried-hill oil reservoirs into gas storage reservoirs. This technology fills a technical gap.

[0284] The evaluation method for converting carbonate buried-hill reservoirs into gas storage facilities provided by this invention is suitable for converting carbonate buried-hill reservoirs into gas storage facilities and has broad application prospects. It has demonstrated excellent results in gas storage conversion projects. Using this method, a specific buried-hill reservoir was predicted to have an effective storage capacity of 7.8 billion cubic meters, a working gas volume of 3.9 billion cubic meters, an annual peak oil production of 1.64 million tons, a cumulative oil production of 29.86 million tons by the end of 30 years, and a stage recovery rate of 10.2%. This provides excellent technical support for the design of gas storage plans. Crude oil is a byproduct of gas storage operations in buried-hill reservoirs. For a specific buried-hill reservoir, the average annual operating revenue was calculated to be 462,415,580 yuan, the average annual total profit was 330,116,780 yuan, the average annual income tax was 20,632,300 yuan, and the average annual net profit was 309,484,480 yuan. The internal rate of return for this project is 18.65%, and the payback period is 9.45 years.

[0285] Example 2

[0286] The embodiment of the present invention provides a carbonate buried hill reservoir reconstruction gas storage evaluation device, referring to Figure 28 Shown, including:

[0287] The trap sealing evaluation module 201 is used to evaluate the caprock sealing and fault sealing properties of the carbonate buried-hill reservoir to obtain a trap sealing evaluation result; the trap sealing evaluation result includes a surface attribute map, an isopach map, and a mudstone coefficient map;

[0288] The favorable reservoir characterization module 202 is configured to obtain an attribute data volume by performing multi-window dip scanning on the time-domain seismic data, generate a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fuse the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result.

[0289] The storage capacity parameter evaluation module 203 is used to calculate the storage capacity parameters of the carbonate buried hill reservoir under the condition of oil, gas and water three-phase saturation in the storage space after the reservoir is converted into a gas storage, and obtain the storage capacity parameter evaluation results;

[0290] The generating module 204 is configured to generate an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir based on the trap sealing evaluation result, the favorable reservoir characterization result, and the storage capacity parameter evaluation result.

[0291] The implementation principle and technical effects of the carbonate buried-hill oil reservoir reconstruction gas storage evaluation device provided in the embodiment of the present invention are similar to those of the aforementioned method embodiment and will not be repeated here.

[0292] Example 3

[0293] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for evaluating the conversion of a carbonate buried-hill oil reservoir into a gas storage reservoir as described in the above method embodiment is implemented.

[0294] The computer-readable storage medium may be included in the device / apparatus described in the above embodiments, or may exist independently without being incorporated into the device / apparatus. The computer-readable storage medium carries one or more programs, which, when executed, implement the method according to the embodiments of the present invention.

[0295] According to an embodiment of the present invention, a computer-readable storage medium may be a non-volatile computer-readable storage medium, such as, but not limited to, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium may be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0296] Example 4

[0297] An embodiment of the present invention provides an electronic device, referring to Figure 29 As shown, it includes a processor 111, a communication interface 112, a memory 113 and a communication bus 114, wherein the processor 111, the communication interface 112 and the memory 113 communicate with each other through the communication bus 114.

[0298] Memory 113, for storing computer programs;

[0299] The processor 111 is configured to implement the method for evaluating the conversion of a carbonate buried hill reservoir into a gas storage reservoir as described in any one of the above method embodiments when executing the program stored in the memory 113 .

[0300] The implementation principle and technical effects of the electronic device provided by the embodiment of the present invention are similar to those of the aforementioned method embodiment and will not be repeated here.

[0301] The memory 113 can be an electronic memory such as a flash memory, an EEPROM (Electrically Erasable Programmable Read-Only Memory), an EPROM, a hard disk, or a ROM. The memory 113 has storage space for program code for executing any of the method steps described above. For example, the storage space for program code can include individual program codes for implementing each of the steps in the method described above. These program codes can be read from or written to one or more computer program products. These computer program products include program code carriers such as a hard disk, a compact disc (CD), a memory card, or a floppy disk. Such computer program products are typically portable or fixed storage units. The storage unit can have storage segments or storage space arranged similarly to the memory 113 in the electronic device described above. The program code can be compressed, for example, in a suitable form. Typically, the storage unit includes a program for executing the method steps according to an embodiment of the present invention, i.e., code that can be read by, for example, the processor 111, and when executed by the electronic device, causes the electronic device to execute the various steps in the method described above.

[0302] In this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article or apparatus. The orientation or positional relationship indicated by the terms "upper", "lower", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0303] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments. It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention is not limited to any single aspect, nor to any single embodiment, nor to any combination and / or permutation of these aspects and / or embodiments. Each aspect and / or embodiment of the present invention can be used alone or in combination with one or more other aspects and / or other embodiments.

[0304] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present invention, which are used to illustrate the technical solutions of the present invention, rather than to limit them. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that any person skilled in the art can modify or easily conceive of changes to the technical solutions described in the above-described embodiments within the technical scope disclosed by the present invention, or replace some of the technical features therein with equivalents. Such modifications, changes, or replacements do not deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities, characterized in that: include: Evaluate the caprock sealing and fault sealing properties of carbonate buried-hill reservoirs to obtain the trap sealing evaluation results; The trap sealing evaluation results include surface attribute map, isopach map and mudstone coefficient map; Scanning time-domain seismic data through multi-window dip angles to obtain an attribute data volume, generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume, and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result; The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage are calculated under the condition of oil, gas and water three-phase saturation in the storage space, and the storage capacity parameter evaluation results are obtained; generating an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir based on the trap sealing evaluation result, the favorable reservoir characterization result, and the storage capacity parameter evaluation result; The storage capacity parameters include storage capacity; the storage capacity parameters are calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation results are obtained, including: The reservoir capacity of carbonate buried hill reservoir is predicted by fractured carbonate reservoir parameter prediction method, and the depth of a gas-oil interface is determined by the following formula. Under this condition, the storage capacity of the gas reservoir can be: Where, is the depth of a gas-oil interface; The depth of a gas-oil interface Under this condition, the storage capacity of the gas reservoir can be achieved; When the gas-oil interface reaches a certain depth When , the volume of rock above this depth; The porosity in the reservoir at which only gas can invade the reservoir space for oil displacement; It is the porosity of the reservoir space where both water and gas can drive oil; is the gas volume coefficient at the average formation pressure and temperature of the gas reservoir; is the pressure under standard conditions; is the temperature under standard conditions; is the average volume deviation coefficient of the gas column; is the average temperature of the air column; is the average formation pressure of the gas reservoir; is the depth of a gas-oil interface The original formation pressure of the reservoir; is the pressure at the top of the gas column; is the relative density of natural gas; is the height of the air column; When the gas-oil interface reaches a certain depth When , the rock volume swept by the oil-water interface; is the rock volume above the oil-water interface; It is the rock volume above the oil-water interface before gas injection.

2. The method for evaluating the conversion of carbonate buried hill reservoirs into gas storage facilities according to claim 1, wherein: The sealing performance of the caprock of carbonate buried-hill reservoirs is evaluated by the following methods: Obtaining direct cover seismic waveforms, and analyzing the direct cover seismic waveforms using a pre-built waveform clustering model to form a surface attribute map; wherein the waveform clustering model is obtained by: Selecting a preset number of traces of data from a target layer segment as a training sample set; wherein the target layer segment is a layer segment of uniform thickness, and the thickness of the target layer segment is greater than half a phase and less than 150ms; Classify the training sample set according to different classification numbers to obtain at least two sample subsets, determine the sum of the intra-class distances of the at least two sample subsets under different classification numbers, and plot a graph of the change of the intra-class distances with the classification number; Obtaining the number of classifications corresponding to the sum of the minimum intra-class distances from the change graph to obtain the target number of classifications; The target classification number is used as the classification number of a pre-constructed BP neural network, and the BP neural network is trained based on the training sample set to obtain a waveform clustering model.

3. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 1, wherein: The sealing performance of the caprock of carbonate buried-hill reservoirs is evaluated by the following methods: Statistics were collected on the direct caprock encountered during drilling in buried-hill traps, and isopach maps and mudstone coefficient maps were drawn.

4. The method for evaluating the conversion of carbonate buried hill oil reservoirs into gas storage facilities according to claim 1, wherein: The fault sealing performance of carbonate buried-hill reservoirs is evaluated by the following methods: The trap formation-hydrocarbon generation-filling period is obtained, and the current activity and closure status of the fault is determined based on the trap formation-hydrocarbon generation-filling period.

5. The method for evaluating the conversion of carbonate buried hill reservoirs into gas storage facilities according to claim 1, wherein: The fault sealing performance of carbonate buried-hill reservoirs is evaluated by the following methods: Fault data of a carbonate buried-hill reservoir is obtained, and fault sealing parameters are determined based on the fault data; the fault sealing parameters include section pressure, sealing coefficient, and mudstone smear coefficient.

6. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 5, characterized in that: The cross-sectional pressure is determined by the following formula: Where, P is the cross-sectional pressure; D is the vertical fault distance; is the oil density; is the water density; is the horizontal ground stress; is the angle between the horizontal ground stress and the fault strike; is the reservoir inclination.

7. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 5, characterized in that: The plugging coefficient includes longitudinal plugging coefficient, lateral plugging coefficient, structural plugging coefficient and storage coefficient; The longitudinal blocking coefficient is determined by the following formula: The lateral blocking coefficient is determined by the following formula: The structural blocking coefficient is determined by the following formula: The storage coefficient is determined by the following formula: Where, is the longitudinal blocking coefficient; is the lateral blocking coefficient; is the structural blocking coefficient; is the storage coefficient; is the vertical drop of the fault; is the thickness of the cap layer; is the fault dip; is the reservoir dip; is the proportionality coefficient; is the lithologic blocking coefficient; is the storage cover thickness.

8. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 5, characterized in that: The mudstone smear coefficient includes mudstone smear potential, mudstone smear factor and fault mudstone ratio; The contamination potential of mudstone is determined by the following formula: The mudstone smear factor is determined by the following formula: The fault mudstone ratio is determined by the following formula: Where, CSP for mudstone taint potential; SSF Smear factor for mudstone; SGR is the fault mudstone ratio; For the The mudstone thickness of each mudstone section; For the The distance from a point on a fault plane to the middle of the nearest mudstone segment on the fault uplift wall; is the thickness of sandstone; For the The mud content of each mudstone section; Based on the mudstone smear potential, mudstone smear factor and fault mudstone ratio, a fault seal grade is determined.

9. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 1, wherein: The method includes: scanning the time domain seismic data through a multi-window dip angle to obtain an attribute data volume; generating a coherence attribute volume, a curvature attribute volume, and an ant volume attribute volume based on the attribute data volume; and fusing the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result, including: The time domain seismic data is processed by multi-window dip scanning to obtain attribute data volume; Taking the attribute data volume as the input of the seismic data volume, generating corresponding coherence attribute volume, curvature attribute volume and ant volume attribute volume; The coherence attribute body and the curvature attribute body are fused with the ant body attribute body according to a preset ratio, and the fused bodies are compared to obtain a favorable reservoir characterization result.

10. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 1, wherein: The storage capacity parameters include upper limit operating pressure and lower limit operating pressure; The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including: The additional pressure on the artificial gas cap after gas injection at the top of the buried hill reservoir is determined by the following formula: Where, For additional pressure; is the formation crude oil weight fraction; is the specific gravity of natural gas; is the air weight ratio; is the gas volume coefficient at the original formation pressure; is the height of the gas cap column; is the unit conversion factor; determining an upper limit operating pressure according to the additional pressure and the original formation pressure; The lower limit operating pressure is determined based on the requirements for peak regulation and produced gas inlet station processing as well as the requirements for working gas volume.

11. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 1, wherein: The storage capacity parameters include storage capacity; The storage capacity parameters of the carbonate buried hill reservoir converted into a gas storage reservoir are calculated under the condition of oil, gas and water three-phase saturation in the storage space to obtain the storage capacity parameter evaluation results, including: The storage capacity of carbonate buried hill reservoirs is predicted by indoor physical simulation experiments and determined by the following formula: Where, is the storage capacity; is the pore volume of the oil layer under original conditions; is the maximum gas drive gas saturation; is the total swept volume coefficient of the gas; is the gas volume coefficient at the original formation pressure.

12. The method for evaluating the conversion of carbonate buried-hill oil reservoirs into gas storage facilities according to claim 1, wherein: The storage capacity parameters include the working gas volume; the storage capacity parameters are calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried hill oil reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation results are obtained, including: Use numerical simulation method to determine the flooding conditions at different working gas ratios, obtain the working gas ratio corresponding to the preset flooding conditions, and obtain the target working gas ratio; The target working gas ratio is multiplied by the storage capacity to obtain the working gas volume.

13. The method for evaluating the conversion of carbonate buried hill reservoirs into gas storage facilities according to claim 12, wherein: The storage capacity parameters include cushion gas volume; the storage capacity parameters are calculated under the condition of oil, gas and water three-phase saturation in the storage space after the carbonate buried hill reservoir is converted into a gas storage reservoir, and the storage capacity parameter evaluation results are obtained, including: The dissolved gas ratio is obtained by performing an indoor core physical simulation gas injection experiment, and the supplementary cushion gas volume is obtained by multiplying the dissolved gas ratio by the residual oil volume; The cushion gas volume is obtained by adding the supplementary cushion gas volume to the difference between the storage capacity and the working gas volume.

14. An evaluation device for converting carbonate buried hill oil reservoirs into gas storage reservoirs, characterized in that: include: The trap sealing evaluation module is used to evaluate the caprock sealing and fault sealing properties of carbonate buried-hill reservoirs and obtain the trap sealing evaluation results; The trap sealing evaluation results include surface attribute map, isopach map and mudstone coefficient map; A favorable reservoir characterization module is used to obtain an attribute data volume by scanning the time domain seismic data with multiple windows and dip angles, generate a coherence attribute volume, a curvature attribute volume and an ant volume attribute volume based on the attribute data volume, and fuse the coherence attribute volume and the curvature attribute volume with the ant volume attribute volume to obtain a favorable reservoir characterization result; The storage capacity parameter evaluation module is used to calculate the storage capacity parameters of the storage space of the carbonate buried hill oil reservoir converted into a gas storage reservoir under the condition of oil, gas and water three-phase saturation, and obtain the storage capacity parameter evaluation results; the storage capacity parameters include storage capacity; the storage capacity parameter evaluation results obtained by calculating the storage capacity parameters of the storage space of the carbonate buried hill oil reservoir converted into a gas storage reservoir under the condition of oil, gas and water three-phase saturation include: The reservoir capacity of carbonate buried hill reservoir is predicted by fractured carbonate reservoir parameter prediction method, and the depth of a gas-oil interface is determined by the following formula. Under this condition, the storage capacity of the gas reservoir can be: Where, is the depth of a gas-oil interface; The depth of a gas-oil interface Under this condition, the storage capacity of the gas reservoir can be achieved; When the gas-oil interface reaches a certain depth When , the volume of rock above this depth; The porosity in the reservoir at which only gas can invade the reservoir space for oil displacement; It is the porosity of the reservoir space where both water and gas can drive oil; is the gas volume coefficient at the average formation pressure and temperature of the gas reservoir; is the pressure under standard conditions; is the temperature under standard conditions; is the average volume deviation coefficient of the gas column; is the average temperature of the air column; is the average formation pressure of the gas reservoir; is the depth of a gas-oil interface The original formation pressure of the reservoir; is the pressure at the top of the gas column; is the relative density of natural gas; is the height of the air column; When the gas-oil interface reaches a certain depth When , the rock volume swept by the oil-water interface; is the rock volume above the oil-water interface; is the rock volume above the oil-water interface before gas injection; A generation module is used to generate an evaluation result of converting a buried hill oil reservoir into a gas storage reservoir based on the trap sealing evaluation result, the favorable reservoir characterization result and the storage capacity parameter evaluation result.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method for evaluating the conversion of a carbonate buried-hill oil reservoir into a gas storage reservoir as described in any one of claims 1 to 13 is implemented.

16. An electronic device, characterized in that: The processor, the communication interface, the memory and the communication bus are connected to each other via the communication bus. Memory for storing computer programs; The processor is configured to implement the method for evaluating the conversion of a carbonate buried hill oil reservoir into a gas storage reservoir as claimed in any one of claims 1 to 13 when executing the program stored in the memory.

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