A method for evaluating reservoir development scale differences in limestone fracture-vuggy reservoirs

Abstract

The present invention discloses a method for evaluating the difference in development scale of limestone fracture-cavity oil reservoirs, comprising the following steps: S1, obtaining static evaluation parameters of the difference in development scale of limestone fracture-cavity oil reservoirs; S2, performing well-seismic calibration according to the static evaluation parameters obtained in S1, carrying out seismic inversion prediction, and obtaining the reservoir boundary of the limestone fracture-cavity oil reservoir scale; S3, obtaining dynamic evaluation parameters of the difference in development scale of limestone fracture-cavity oil reservoirs; S4, obtaining the equivalent boundary and dynamic geological reserve of the limestone fracture-cavity oil reservoir within the control range of a single well; S5, performing secondary iterative calibration of the seismic attribute body according to the data obtained in S1-S4, measuring the space of the development scale of the limestone fracture-cavity oil reservoirs, and clarifying the difference in the development scale of the limestone fracture-cavity oil reservoirs. The present invention provides a method for evaluating the difference in development scale of limestone fracture-cavity oil reservoirs, a computer device, and a computer-readable storage medium.

Description

Technical Field

[0001] The present invention relates to the technical field of fine description of carbonate reservoirs, and more specifically, to a method for evaluating the differences in reservoir development scale of limestone fracture-cavity reservoirs. Background Art

[0002] For carbonate reservoirs, especially limestone fracture-cave reservoirs, the reservoir heterogeneity is extremely strong. In order to improve the exploration and development effect of this type of reservoir, it is very important to evaluate the differences in the development scale of fracture-cave reservoirs in different zones. At present, the research on the development scale of limestone fracture-cave reservoirs mainly adopts the technical means of combining static geophysical methods with single well drilling data. Since this type of reservoir is generally affected by karstification, it is difficult to obtain core samples in the main fluid supply layer, and even difficult to obtain electrical logging curves. Therefore, the application of single well data is mainly concentrated on the calibration of layer positions, emptying and leakage layers. The seismic data is calibrated by single well logging and logging data, and then the spatial distribution characteristics of the reservoir are predicted. This is also the commonly used method of identifying the "beading" characteristics of seismic profiles through various geophysical technical methods, and then finding favorable reservoirs and carrying out well deployment. Geophysical technical methods based mainly on static calibration have achieved good application results in the exploration and evaluation stages of this type of oil reservoir. However, with the continuous development of the oil field, the high-quality fracture-vuggy reservoir targets have basically completed the well deployment in the previous stage, resulting in a gradual reduction in the spacing between new wells and an increasing difficulty in development. The existing technology mainly uses static data to carry out reservoir prediction. During the actual drilling of oil and gas wells, the probability of encountering dry layers, water layers and invalid reservoirs gradually increases, which cannot meet the technical requirements for the fine development of this type of oil reservoir. Summary of the invention

[0003] The purpose of the present invention is to provide a method for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs, a computer device and a computer-readable storage medium.

[0004] In order to achieve these purposes and other advantages according to the present invention, a method for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs is provided, comprising the following steps:

[0005] S1. Obtain static evaluation parameters of the development scale differences of limestone fracture-vuggy reservoirs;

[0006] S2. According to the static evaluation parameters obtained in S1, well-seismic calibration is performed, and seismic inversion prediction is carried out to obtain the reservoir boundary of the limestone fracture-cavity reservoir at the reservoir scale;

[0007] S3. Obtain dynamic evaluation parameters of the scale differences of limestone fracture-vuggy reservoir development;

[0008] S4. Obtain the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir within the control range of a single well;

[0009] S5. Based on the data obtained in S1-S4, a secondary iterative calibration of the seismic attribute body is performed to measure the spatial development scale of the limestone fracture-vuggy reservoir and clarify the differences in the development scale of the limestone fracture-vuggy reservoir.

[0010] Preferably, in the method for evaluating the development scale difference of a limestone fracture-vuggy oil reservoir, the static evaluation parameters at least include:

[0011] The stratification data of the oil well, the emptying, leakage and drilling time data occurring in the target layer during the drilling process, the reservoir development of the target layer, the statistics of the top and bottom depths of various types of reservoirs, the effective thickness and static-to-gross ratio of the reservoir encountered by a single well, the number of fractures developed in the target layer, the occurrence and fracture width data.

[0012] Preferably, in the method for evaluating the development scale difference of a limestone fracture-vuggy oil reservoir, the dynamic evaluation parameters at least include:

[0013] According to the daily oil production and water content change characteristics of a single well, the production dynamic characteristics of a single well are divided into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type or no production capacity type;

[0014] According to the cumulative oil and gas equivalent production of a single well, the benefits of a single well are divided into high-efficiency wells, effective wells, low-efficiency wells or ineffective wells;

[0015] According to the relationship between the cumulative production of a single well and oil pressure, the relationship curves between the cumulative oil and gas equivalent production of a single well in each stage and the cumulative liquid production in each stage and oil pressure drop are drawn respectively, and then the oil and gas equivalent index and liquid production index of a single well in different production stages are determined.

[0016] Preferably, in the method for evaluating the development scale difference of a limestone fracture-vuggy oil reservoir, according to the relationship between the cumulative production of a single well and the oil pressure, respectively drawing the relationship curves between the cumulative oil and gas equivalent of a single well and the cumulative liquid production of a stage and the oil pressure drop, specifically comprising:

[0017] Fit the relationship curve between the cumulative oil and gas equivalent production of a single well and the oil pressure drop under the same working system to determine the oil and gas equivalent index of a single well at a certain stage;

[0018] The relationship curve between the cumulative liquid production and oil pressure drop of a single well in the same working system is fitted to determine the liquid production index of a single well in a certain stage.

[0019] Preferably, in the method for evaluating the development scale difference of limestone fracture-vuggy oil reservoir, obtaining the equivalent boundary and dynamic geological reserves of the limestone fracture-vuggy reservoir within the control range of a single well in S4 specifically includes:

[0020] Based on the pressure recovery test data, a double logarithmic curve is drawn to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test;

[0021] Based on the bottom hole flowing pressure monitoring data, the advanced production decline method is used to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the oil well production period.

[0022] Preferably, in the method for evaluating the development scale difference of a limestone fracture-vuggy oil reservoir, when obtaining the equivalent boundary and dynamic geological reserves of a single well control range during a pressure buildup test:

[0023] For single wells with pressure recovery well tests, the pressure recovery well tests are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range; for single wells without pressure recovery well tests, the flowing pressure monitoring data are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range.

[0024] Preferably, in the method for evaluating the difference in development scale of limestone fracture-cavity oil reservoir, when performing secondary iterative calibration of the seismic attribute body according to the data obtained in S1-S4 in S5, the space of the development scale of the limestone fracture-cavity reservoir is measured to clarify the difference in the development scale of the limestone fracture-cavity reservoir. Specifically, it includes:

[0025] Summarize the static evaluation parameters of reservoir development scale differences of all single wells in the target limestone fracture-vuggy reservoir and establish the first data analysis database;

[0026] Summarize the reservoir development scale difference dynamic evaluation parameters of all single wells in the target limestone fracture-vuggy reservoir and establish the second data analysis database;

[0027] The first data analysis database and the second data analysis database are aggregated to establish a single well standard sample database for reservoirs of different scales in limestone fracture-cavity reservoirs;

[0028] According to the single well standard sample database, single wells that have been shut down for a long time under current technical conditions in different zone ranges and different reservoir development scales are selected as standard samples in the target limestone reservoir research area, and the selected standard sample wells are used to perform secondary iterative calibration of the seismic attribute body;

[0029] According to the secondary iterative calibration results of seismic attributes, the uncertainty of the original seismic attribute calibration is improved, the spatial prediction of the development scale of limestone fracture-vuggy reservoirs is realized, and finally the differences in the development scale of limestone fracture-vuggy reservoirs are clarified.

[0030] The present invention also provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for evaluating the differences in development scale of limestone fracture-vuggy oil reservoirs described in any one of the above items is implemented.

[0031] The present invention also provides a computer-readable storage medium, which stores a computer program for executing any of the above-mentioned methods for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs.

[0032] The present invention provides a method for evaluating the difference in development scale of limestone fracture-cavity oil reservoirs, a computer device and a computer-readable storage medium, which are specially used for research on limestone fracture-cavity oil reservoirs with very complex reservoir conditions. In the process of evaluating the difference in development scale of fracture-cavity oil reservoirs, the drilling and completion data, logging interpretation data, production dynamic data, pressure recovery test interpretation data, flow pressure monitoring data and seismic results of the oil field are fully utilized, dynamic and static information are fully integrated, a single well standard sample database is established, and then iterative calibration of seismic data bodies is carried out, and spatial prediction of fracture-cavity reservoirs is carried out. The research results can be applied to the full identification and prediction of the development scale and effectiveness of this type of reservoir, and play a very important role in the connectivity analysis of this type of reservoir, the division of reservoir units and the formulation of development adjustment measures.

[0033] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a flow chart of the method for evaluating the reservoir development scale difference of limestone fracture-vuggy oil reservoirs according to the present invention;

[0035] Figure 2 A comprehensive histogram of a typical well in one embodiment of the present invention;

[0036] Figure 3 This is a typical well seismic calibration diagram in one embodiment of the present invention;

[0037] Figure 4 The production dynamic characteristic curve diagram of a typical well P1 in one embodiment of the present invention (high-yield and stable-yield type);

[0038] Figure 5 The production performance characteristic curve diagram of a typical well P2 in one embodiment of the present invention (low-production and stable-production type);

[0039] Figure 6 The production performance characteristic curve diagram of a typical well P3 (high-yield intermittent type) in one embodiment of the present invention;

[0040] Figure 7 The production performance characteristic curve diagram of a typical well P4 in one embodiment of the present invention (low-production interval opening type);

[0041] Figure 8 A curve diagram showing the relationship between the cumulative fluid production and the oil pressure of a typical well in one embodiment of the present invention;

[0042] Fig. 9 A curve diagram showing the relationship between the cumulative oil and gas equivalent production and the oil pressure of a typical well in one embodiment of the present invention;

[0043] Fig.10 A double logarithmic diagnostic curve diagram of a typical well test interpretation in one embodiment of the present invention;

[0044] Fig.11 It is a fitting curve diagram of the high-level production decline method of a typical well in one embodiment of the present invention;

[0045] Fig.12 It is a production dynamic characteristic curve diagram of a typical well that is shut down for a long time due to high water content after water injection due to no production in a single well in one embodiment of the present invention;

[0046] Fig.13 It is a production dynamic characteristic curve diagram of a typical well that is eventually shut down for a long time due to needle-like production after water injection after no production in a single well in one embodiment of the present invention;

[0047] Fig.14 It is a production dynamic characteristic curve diagram of a typical well that is shut down for a long time after water injection due to no production in a single well in one embodiment of the present invention;

[0048] Fig.15 This is a spatial prediction map of reservoir development scale of a typical well after secondary seismic iterative calibration in one embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0050] An embodiment of the present invention provides a method for evaluating the development scale difference of a limestone fracture-vuggy oil reservoir, comprising the following steps:

[0051] S1. Obtain static evaluation parameters of the development scale differences of limestone fracture-vuggy reservoirs;

[0052] S2. According to the static evaluation parameters obtained in S1, well-seismic calibration is performed, and seismic inversion prediction is carried out to obtain the reservoir boundary of the limestone fracture-cavity reservoir at the reservoir scale;

[0053] S3. Obtain dynamic evaluation parameters of the scale differences of limestone fracture-vuggy reservoir development;

[0054] S4. Obtain the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir within the control range of a single well;

[0055] S5. Based on the data obtained in S1-S4, a secondary iterative calibration of the seismic attribute body is performed to measure the spatial development scale of the limestone fracture-vuggy reservoir and clarify the differences in the development scale of the limestone fracture-vuggy reservoir.

[0056] The static evaluation parameters include at least:

[0057] The stratification data of the oil well, the emptying, leakage and drilling time data occurring in the target layer during the drilling process, the reservoir development of the target layer, the statistics of the top and bottom depths of various types of reservoirs, the effective thickness and static-to-gross ratio of the reservoir encountered by a single well, the number of fractures developed in the target layer, the occurrence and fracture width data.

[0058] The dynamic evaluation parameters include at least:

[0059] According to the daily oil production and water content change characteristics of a single well, the production dynamic characteristics of a single well are divided into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type or no production capacity type;

[0060] According to the cumulative oil and gas equivalent production of a single well, the benefits of a single well are divided into high-efficiency wells, effective wells, low-efficiency wells or ineffective wells;

[0061] According to the relationship between the cumulative production of a single well and oil pressure, the relationship curves between the cumulative oil and gas equivalent production of a single well in each stage and the cumulative liquid production in each stage and oil pressure drop are drawn respectively, and then the oil and gas equivalent index and liquid production index of a single well in different production stages are determined.

[0062] Among them, according to the relationship between the cumulative production of a single well and the oil pressure, the relationship curves of the cumulative oil and gas equivalent of a single well in a stage and the cumulative liquid production in a stage and the oil pressure drop are drawn respectively, specifically including:

[0063] Fit the relationship curve between the cumulative oil and gas equivalent production of a single well and the oil pressure drop under the same working system to determine the oil and gas equivalent index of a single well at a certain stage;

[0064] The relationship curve between the cumulative liquid production and oil pressure drop of a single well in the same working system is fitted to determine the liquid production index of a single well in a certain stage.

[0065] Among them, when obtaining the equivalent boundary and dynamic geological reserves of the limestone fracture-cave reservoir within the control range of a single well in S4, it specifically includes:

[0066] Based on the pressure recovery test data, a double logarithmic curve is drawn to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test;

[0067] Based on the bottom hole flowing pressure monitoring data, the advanced production decline method is used to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the oil well production period.

[0068] Among them, when obtaining the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test:

[0069] For single wells with pressure recovery well tests, the pressure recovery well tests are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range; for single wells without pressure recovery well tests, the flowing pressure monitoring data are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range.

[0070] Among them, in S5, when performing secondary iterative calibration of the seismic attribute body based on the data obtained from S1-S4, the spatial scale of the development of the limestone fracture-cavity reservoir is measured to clarify the differences in the scale of development of the limestone fracture-cavity reservoir. Specifically, it includes:

[0071] Summarize the static evaluation parameters of reservoir development scale differences of all single wells in the target limestone fracture-vuggy reservoir and establish the first data analysis database;

[0072] Summarize the reservoir development scale difference dynamic evaluation parameters of all single wells in the target limestone fracture-vuggy reservoir and establish the second data analysis database;

[0073] The first data analysis database and the second data analysis database are aggregated to establish a single well standard sample database for reservoirs of different scales in limestone fracture-cavity reservoirs;

[0074] According to the single well standard sample database, single wells that have been shut down for a long time under current technical conditions in different zone ranges and different reservoir development scales are selected as standard samples in the target limestone reservoir research area, and the selected standard sample wells are used to perform secondary iterative calibration of the seismic attribute body;

[0075] According to the secondary iterative calibration results of seismic attributes, the uncertainty of the original seismic attribute calibration is improved, the spatial prediction of the development scale of limestone fracture-vuggy reservoirs is realized, and finally the differences in the development scale of limestone fracture-vuggy reservoirs are clarified.

[0076] The present invention also provides a computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for evaluating the differences in development scale of limestone fracture-vuggy oil reservoirs described in any one of the above items is implemented.

[0077] The present invention also provides a computer-readable storage medium, which stores a computer program for executing any of the above-mentioned methods for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs.

[0078] In addition, if Figure 1 As shown, an embodiment of the present invention provides a method for evaluating the difference in development scale of limestone fracture-vuggy oil reservoirs, such as Figure 1 As shown, the method includes:

[0079] S101 obtains static evaluation parameters of the scale differences of limestone fracture-vuggy reservoir development within the control range of a single well based on drilling, logging and imaging logging interpretation data;

[0080] S102 obtains reservoir-scale static evaluation parameters for the development scale differences of limestone fracture-vuggy reservoirs based on seismic inversion data;

[0081] S103 obtains dynamic evaluation parameters of the scale difference of limestone fracture-cavity reservoir development based on single well production dynamic data;

[0082] S104 Obtain the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir based on dynamic monitoring data;

[0083] S105 Based on the results of dynamic and static evaluation, a single well standard sample database of different scale reservoirs of limestone fracture-cavity reservoirs was established;

[0084] S106 performs secondary iterative calibration of the seismic attribute body based on the dynamic and static characterization parameters, equivalent boundaries and dynamic geological reserve evaluation results of the limestone fracture-vuggy reservoir, realizes the spatial prediction of the development scale of the limestone fracture-vuggy reservoir, and finally clarifies the differences in the development scale of the limestone fracture-vuggy reservoir.

[0085] The static evaluation parameters of the scale difference of fracture-vuggy reservoir development within the control range of a single well obtained based on drilling, logging and imaging logging interpretation data include:

[0086] Based on the drilling and completion data, obtain the layer data of the oil well and the emptying, leakage and drilling time data occurring in the target layer during the drilling process;

[0087] According to the logging data, the reservoir development of the target layer is obtained, and the reservoir is divided into type I, II, III reservoirs and dry layers. The top depth and bottom depth of each type of reservoir are counted, and the effective thickness and static-to-gross ratio of the reservoir encountered by a single well are calculated;

[0088] According to the imaging logging data, the number, occurrence and width of fractures in the target layer are obtained.

[0089] The method of obtaining reservoir-scale static evaluation parameters of the scale differences of limestone fracture-vuggy reservoir development based on seismic inversion data includes:

[0090] According to the single well static evaluation parameters obtained in S101, well seismic calibration is carried out and seismic inversion prediction is carried out;

[0091] Based on the seismic inversion data, the reservoir boundary of the limestone fracture-vuggy reservoir at the reservoir scale is obtained.

[0092] The dynamic evaluation parameters of the scale difference of limestone fracture-cavity reservoir development are obtained based on the single well production dynamic data, including:

[0093] According to the daily oil production and water content change characteristics of a single well, the production dynamic characteristics of a single well are divided into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type, and no production capacity type, and classified statistical analysis is performed;

[0094] According to the cumulative oil and gas equivalent production of a single well at a certain stage, combined with the overall production status of the oil field, the single well benefits are divided into high-efficiency wells, effective wells, low-efficiency wells and invalid wells, and classified and statistically analyzed;

[0095] According to the correlation between the cumulative production of a single well and oil pressure, the relationship curves between the cumulative oil and gas equivalent production of a single well in each stage and the cumulative liquid production in each stage and oil pressure drop are drawn respectively, and then the oil and gas equivalent index and liquid production index of a single well in different production stages are determined, and classified statistical analysis is carried out.

[0096] The production dynamic characteristics of a single well are divided into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type and no production capacity type according to the daily oil production and water content change characteristics of the single well. This means drawing a single well production dynamic curve and performing classification analysis based on the actual production conditions of the oil field, including:

[0097] According to the changes in daily oil production, water content, well opening rate and working system of a single well over time, a production dynamic curve is drawn. According to the actual production situation in different regions and the shape of the curve, the single well capacity classification evaluation results of high-yield and stable production type, high-yield and intermittent opening type, low-yield and stable production type, low-yield and intermittent opening type and no production capacity type are obtained.

[0098] Among them, according to the cumulative oil and gas equivalent production of a single well in the stage, combined with the overall production status of the oil field, the single well benefits are divided into high-efficiency wells, effective wells, low-efficiency wells and invalid wells, including:

[0099] According to the cumulative oil and gas equivalent production of a single well at a certain stage, and combined with the actual drilling and completion of the oil field as well as the ground investment, the cumulative oil and gas equivalent production of a single well under the current economic conditions is classified and analyzed to obtain the classification and evaluation results of the single well benefits of high-efficiency wells, effective wells, inefficient wells and invalid wells.

[0100] Among them, according to the correlation between the cumulative production of a single well and the oil pressure, a curve of the relationship between the cumulative production of a single well and the oil pressure drop in a stage is drawn, and then the oil and gas production equivalent index and the liquid production index of the single well in different production stages are determined, including:

[0101] According to the relationship curve between the cumulative oil and gas equivalent production of a single well and the oil pressure drop under the same working system, the correlation fitting is performed to determine the oil and gas equivalent index of a single well at a certain stage;

[0102] According to the relationship curve between the cumulative liquid production and oil pressure drop of a single well in the same working system, the correlation fitting is performed to determine the liquid production index of a single well in a certain stage;

[0103] Based on the calculated oil and gas production equivalent index and liquid production index of different single wells, combined with the actual development effect of the oil field, a classification, summary and analysis are carried out.

[0104] Wherein, obtaining the equivalent boundary and dynamic geological reserves of limestone fracture-cavity reservoirs based on dynamic monitoring data includes:

[0105] The equivalent boundary and dynamic geological reserves of the fracture-vuggy reservoir within the control range of a single well are obtained based on dynamic monitoring data.

[0106] The dynamic monitoring data include pressure recovery well test data and bottom hole flow pressure monitoring data.

[0107] Wherein, the equivalent boundary and dynamic geological reserves of the fracture-cavity reservoir within the control range of a single well are obtained based on the pressure recovery well test data and the bottom hole flow pressure monitoring data, including:

[0108] Based on the pressure recovery test data, a double logarithmic curve is drawn to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test;

[0109] Based on the bottom hole flowing pressure monitoring data, the advanced production decline method is used to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the oil well production period.

[0110] Among them, for a single well with a pressure recovery well test, the pressure recovery well test is used to obtain the equivalent boundary and dynamic geological reserves of the single well control range; and for a single well without a pressure recovery well test, the flow pressure monitoring data can be used to obtain the equivalent boundary and dynamic geological reserves of the single well control range.

[0111] According to the dynamic and static evaluation results, a single well standard sample database of different scale reservoirs of limestone fracture-cavity reservoirs is established, including:

[0112] The static evaluation parameters of reservoir development scale differences of all single wells in the target limestone fracture-vuggy reservoir are summarized to establish the first data analysis database;

[0113] The reservoir development scale difference dynamic evaluation parameters of all single wells in the target limestone fracture-vuggy reservoir are summarized to establish a second data analysis database;

[0114] The first data analysis database and the second data analysis database are summarized to establish a single well standard sample database for reservoirs of different scales developed in limestone fracture-vuggy reservoirs.

[0115] Among them, the secondary iterative calibration of the seismic attribute body is carried out according to the dynamic and static characterization parameters, equivalent boundaries and dynamic geological reserve evaluation results of the limestone fracture-cavity reservoir, so as to realize the spatial prediction of the development scale of the limestone fracture-cavity reservoir and finally clarify the differences in the development scale of the limestone fracture-cavity reservoir, including:

[0116] According to the single well standard sample database established in S105, single wells that have been shut down for a long time under current technical conditions in different zones and reservoir development scales in the target limestone reservoir research area are selected as standard samples, and the selected standard sample wells are used to perform secondary iterative calibration of the seismic attribute body;

[0117] Based on the secondary iterative calibration results of seismic attributes, the uncertainty of the original seismic attribute calibration is improved, and it is promoted and applied in similar areas to achieve spatial prediction of the development scale of limestone fracture-vuggy reservoirs, and ultimately clarify the differences in the development scale of limestone fracture-vuggy reservoirs.

[0118] The following is an embodiment of a method for evaluating the reservoir development scale difference of a limestone fracture-vuggy oil reservoir in a certain block of an oil field using the method of the present invention, which includes the following specific steps:

[0119] (1) Based on the drilling, logging and imaging logging interpretation data, the static evaluation parameters of the scale difference of the limestone fracture-vuggy reservoir development within the control range of a single well are obtained, which specifically includes the following three steps:

[0120] The first step is to obtain the stratification data of the oil well and the emptying, leakage and drilling time data in the target layer during the drilling process based on the drilling and completion data. Figure 2 and Table 1, where Figure 2 1 is a comprehensive histogram of a typical well in an embodiment of the present invention, and Table 1 is a statistical table of drilling and completion data of a typical well.

[0121] Table 1 Statistics of typical well drilling and completion data

[0122]

[0123] The second step is to obtain the reservoir development of the target layer according to the logging data, and divide the reservoir into Class I, II, III reservoirs and dry layers. The top depth and bottom depth of each type of reservoir are counted. The analysis of typical wells is shown in Table 2. According to the actual production situation, Class I and II reservoirs are regarded as effective reservoirs. The effective thickness of the reservoir encountered by the well is calculated to be 38.5m, and the static-to-gross ratio is 0.31.

[0124] Table 2 Statistical results of logging interpretation of typical wells

[0125]

[0126] The third step is to obtain the number, occurrence, and width of fractures in the target layer based on the imaging logging data. The interpretation results of typical wells are shown in Table 3.

[0127] Table 3 Statistics of key parameters of imaging logging interpretation in typical wells

[0128] Number of cracks Occurrence (dip ∠ dip angle) Average crack width, μm 4 140°∠88° 25

[0129] (2) Based on the seismic inversion data, the reservoir-scale static evaluation parameters of the development scale differences of the limestone fracture-vuggy reservoir are obtained, which specifically includes the following two steps:

[0130] The first step is to perform well-seismic calibration and carry out seismic inversion prediction based on the single well static evaluation parameters obtained in step (1);

[0131] The second step is to obtain the reservoir boundary of the limestone fracture-cavity reservoir based on the seismic inversion data. Figure 3 .

[0132] (3) Based on the single well production dynamic data, the dynamic evaluation parameters of the scale difference of limestone fracture-vuggy reservoir development are obtained, which specifically includes the following three steps:

[0133] The first step is to classify the production dynamic characteristics of a single well into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type, and no production capacity type according to the daily oil production and water content change characteristics of the single well, and conduct classification and statistical analysis, see Table 4;

[0134] The second step is to classify the single well benefits into high-efficiency wells, effective wells, low-efficiency wells and ineffective wells according to the cumulative oil and gas equivalent production of the single well stage and the overall production status of the oil field, and conduct classification and statistical analysis, see Table 4;

[0135] The third step is to draw the relationship curves between the cumulative oil and gas equivalent production of a single well and the cumulative liquid production of a single well and the oil pressure drop according to the correlation between the cumulative production of a single well and the oil pressure drop, and then determine the oil and gas equivalent index and liquid production index of the single well in different production stages, and conduct classified statistical analysis, see Table 4.

[0136] In order to further illustrate the differences in production performance characteristics of different types of oil wells, relevant performance curves of typical wells were drawn, see Figure 4-Figure 9 ,in Figure 4 is a production dynamic characteristic curve diagram of a typical well P1 in an embodiment of the present invention (high-yield and stable-yield type), Figure 5 is a production performance characteristic curve diagram of a typical well P2 in an embodiment of the present invention (low-production and stable-production type), Figure 6 : is a production performance characteristic curve diagram of a typical well P3 in an embodiment of the present invention (high-yield intermittent type), Figure 7: is a production performance characteristic curve diagram of a typical well P4 in an embodiment of the present invention (low-production interval opening type), Figure 8 is a curve diagram showing the relationship between the cumulative fluid production and the oil pressure in a typical well in an embodiment of the present invention. Fig. 9 Graph showing the relationship between the cumulative oil and gas equivalent production and the oil pressure of a typical well in an embodiment of the present invention.

[0137] Table 4 Summary of production performance evaluation parameters of typical wells

[0138]

[0139] (4) Obtaining the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir based on dynamic monitoring data, which specifically includes the following two steps:

[0140] The first step is to draw a double logarithmic curve for the oil wells that have been tested for pressure recovery well testing based on the pressure recovery well testing data to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test. The equivalent boundary of the typical well P1 is 588m and the dynamic geological reserves are 269,000 tons. The results are shown in Fig.10 , Table 5, where Fig.10 is a double logarithmic diagnostic curve diagram of a typical well test interpretation in an embodiment of the present invention, and Table 5 is a table of typical well pressure recovery test interpretation results.

[0141] Table 5 Typical well pressure recovery test interpretation results

[0142] name Numeric Fluidity, mD / mPa.s 0.056 Inner zone formation coefficient, mD.m 0.811 Inner zone permeability, mD 0.0145 Composite radius, m 588 External zone permeability, mD 0.00498 <![CDATA[Dynamic Geological Reserves, 10 4 t]]> 26.9

[0143] In the second step, for oil wells without pressure recovery test, the advanced production decline method is used to obtain the equivalent boundary of the single well control range during the production period of the oil well according to the bottom hole flow pressure monitoring data. The equivalent boundary of the typical well interpretation is 456.6m, and the dynamic geological reserves are 218,360 tons. Fig.11 , Table 6 and Table 7. Among them Fig.11 6 is a fitting curve diagram of the advanced production decline method for a typical well in an embodiment of the present invention. Table 6 and Table 7 are respectively a table of equivalent boundary interpretation results calculated by the advanced production decline method for a typical well and a table of dynamic geological reserve interpretation results calculated by the advanced production decline method for a typical well.

[0144] Table 6 Results of equivalent boundary interpretation calculated by advanced production decline method for typical wells

[0145]

[0146] Table 7. Results of dynamic geological reserves interpretation calculated by advanced production decline method for typical wells

[0147]

[0148] (5) Based on the dynamic and static evaluation results, a single-well standard sample database for different scale reservoirs of limestone fracture-vuggy reservoirs is established, which specifically includes the following three steps:

[0149] The first step is to summarize the static evaluation parameters of reservoir development scale differences of all single wells in the target limestone fracture-cave reservoir and establish the first data analysis database;

[0150] The second step is to summarize the reservoir development scale difference dynamic evaluation parameters of all single wells in the target limestone fracture-vuggy reservoir and establish a second data analysis database;

[0151] The third step is to aggregate the first data analysis database and the second data analysis database to establish a single well standard sample database for reservoirs of different scales in limestone fracture-vuggy reservoirs.

[0152] (6) Based on the dynamic and static characterization parameters, equivalent boundaries and dynamic geological reserve evaluation results of the limestone fracture-vuggy reservoir, a secondary iterative calibration of the seismic attribute body is performed to achieve the spatial prediction of the development scale of the limestone fracture-vuggy reservoir, and then clarify the differences in the development scale of the limestone fracture-vuggy reservoir. Specifically, it includes the following two steps:

[0153] In the first step, a module was established based on the single well standard sample database. Single wells that were shut down for a long time under current technical conditions in different zones and reservoir development scales were selected as standard samples in the target limestone reservoir research area, and the selected standard sample wells were used for secondary iterative calibration of the seismic attribute body. To further illustrate the production dynamic characteristics of long-term shut-in wells, single well production dynamic curves for wells shut down for different reasons were drawn, see Figure 12-14 ,in Fig.12 This is a production dynamic characteristic curve of a typical well that has been shut down for a long time due to high water content after water injection due to no production in a single well in an embodiment of the present invention. Fig.13 Figure 14 is a production dynamic characteristic curve diagram of a typical well that was eventually shut down for a long time due to needle-like production after water injection after a single well had no production in an embodiment of the present invention. Figure 15 is a production dynamic characteristic curve diagram of a typical well that was eventually shut down for a long time due to water injection after a single well had no production in an embodiment of the present invention.

[0154] In the second step, based on the secondary iterative calibration results of seismic attributes, the uncertainty of the original seismic attribute calibration is improved, and the method is promoted and applied in similar areas to achieve spatial prediction of the development scale of limestone fracture-vuggy reservoirs, and finally clarify the differences in the development scale of limestone fracture-vuggy reservoirs. Fig.15 This is a spatial prediction diagram of reservoir development scale of a typical well after secondary seismic iterative calibration in an embodiment of the present invention.

[0155] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the implementation modes. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the embodiments shown and described herein.

Claims

1. A method for evaluating the difference in reservoir development scale of limestone fracture-vuggy oil reservoirs, characterized in that: The following steps are involved: S1. Obtain static evaluation parameters of the development scale differences of limestone fracture-vuggy reservoirs; S2. According to the static evaluation parameters obtained in S1, well-seismic calibration is performed, and seismic inversion prediction is carried out to obtain the reservoir boundary of the limestone fracture-cavity reservoir at the reservoir scale; S3. Obtain dynamic evaluation parameters of the scale differences of limestone fracture-vuggy reservoir development; S4. Obtain the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir within the control range of a single well; S5. Based on the data obtained in S1-S4, the seismic attribute body is calibrated for the second iteration to predict the spatial development scale of the limestone fracture-cavity reservoir and clarify the differences in the development scale of the limestone fracture-cavity reservoir, including: Summarize the static evaluation parameters of reservoir development scale differences of all single wells in the target limestone fracture-vuggy reservoir and establish the first data analysis database; Summarize the reservoir development scale difference dynamic evaluation parameters of all single wells in the target limestone fracture-vuggy reservoir and establish the second data analysis database; The first data analysis database and the second data analysis database are aggregated to establish a single well standard sample database for reservoirs of different scales in limestone fracture-cavity reservoirs; According to the single well standard sample database, single wells that have been shut down for a long time under current technical conditions in different zone ranges and different reservoir development scales are selected as standard samples in the target limestone reservoir research area, and the selected standard sample wells are used to perform secondary iterative calibration of the seismic attribute body; According to the secondary iterative calibration results of seismic attributes, the uncertainty of the original seismic attribute calibration is improved, the spatial prediction of the development scale of limestone fracture-vuggy reservoirs is realized, and finally the differences in the development scale of limestone fracture-vuggy reservoirs are clarified.

2. A method for evaluating reservoir development scale differences in limestone fracture-vuggy oil reservoirs according to claim 1, characterized in that: The static evaluation parameters include at least: The stratification data of the oil well, the emptying, leakage and drilling time data occurring in the target layer during the drilling process, the reservoir development of the target layer, the statistics of the top and bottom depths of various types of reservoirs, the effective thickness and static-to-gross ratio of the reservoir encountered by a single well, the number of fractures developed in the target layer, the occurrence and fracture width data.

3. A method for evaluating reservoir development scale differences in limestone fracture-vuggy oil reservoirs according to claim 1, characterized in that: The dynamic evaluation parameters include at least: According to the daily oil production and water content change characteristics of a single well, the production dynamic characteristics of a single well are divided into high-yield and stable production type, high-yield and intermittent production type, low-yield and stable production type, low-yield and intermittent production type or no production capacity type; According to the cumulative oil and gas equivalent production of a single well, the benefits of a single well are divided into high-efficiency wells, effective wells, low-efficiency wells or ineffective wells; According to the relationship between the cumulative production of a single well and oil pressure, the relationship curves between the cumulative oil and gas equivalent production of a single well in each stage and the cumulative liquid production in each stage and oil pressure drop are drawn respectively, and then the oil and gas equivalent index and liquid production index of a single well in different production stages are determined.

4. A method for evaluating reservoir development scale differences in limestone fracture-vuggy oil reservoirs according to claim 1, characterized in that: According to the relationship between the cumulative production of a single well and the oil pressure, the relationship curves of the cumulative oil and gas equivalent of a single well in a stage and the cumulative liquid production in a stage and the oil pressure drop are drawn, specifically including: Fit the relationship curve between the cumulative oil and gas equivalent production of a single well and the oil pressure drop under the same working system to determine the oil and gas equivalent index of a single well at a certain stage; The relationship curve between the cumulative liquid production and oil pressure drop of a single well in the same working system is fitted to determine the liquid production index of a single well in a certain stage.

5. The method for evaluating the reservoir development scale difference of limestone fracture-vuggy oil reservoirs according to claim 1, characterized in that: When obtaining the equivalent boundary and dynamic geological reserves of the limestone fracture-cavity reservoir within the control range of a single well in S4, it specifically includes: Based on the pressure recovery test data, a double logarithmic curve is drawn to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the pressure recovery test; Based on the bottom hole flowing pressure monitoring data, the advanced production decline method is used to obtain the equivalent boundary and dynamic geological reserves of the single well control range during the oil well production period.

6. A method for evaluating reservoir development scale differences in limestone fracture-vuggy oil reservoirs according to claim 5, characterized in that: To obtain the equivalent boundary and dynamic geological reserves of a single well control range during a pressure buildup test: For single wells with pressure recovery well tests, the pressure recovery well tests are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range; for single wells without pressure recovery well tests, the flowing pressure monitoring data are used to obtain the equivalent boundaries and dynamic geological reserves of the single well control range.

7. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs according to any one of claims 1 to 6 is implemented.

8. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program for executing the method for evaluating the differences in reservoir development scale of limestone fracture-vuggy oil reservoirs according to any one of claims 1 to 6.

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