Method and device for researching uncertainty of geological reserves of oil reservoir

Abstract

The invention belongs to the field of oil and gas field development, and discloses a method and device for researching the uncertainty of oil reservoir geological reserves, and the method comprises the steps: analyzing the uncertainty of a structure, the uncertainty of a sedimentary facies, the uncertainty of porosity, the uncertainty of water saturation, the uncertainty of an oil-water interface and the uncertainty of a volume coefficient; based on the analysis result of each uncertainty, geological reserve sensitivity analysis is carried out; based on the analysis result of each uncertainty, carrying out geological reserve uncertainty analysis; and performing quality control on the uncertainty analysis of the geological reserves. Through uncertainty analysis, the geological reserve distribution condition of the oil reservoir can be backed up, and a good foundation is laid for selection of oil and gas field development modes, compilation of development schemes and the like. And meanwhile, the method comprises quality control on a research result, so that the uncertainty understanding on the geological reserves of the oil reservoir is more reliable.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas field development, and in particular relates to a method and a device for studying uncertainty of oil reservoir geological reserves. Background Art

[0002] Due to limited data and other objective conditions, underground geological research on oil and gas reservoirs often involves many uncertainties. As one of the most important parameters in reservoir development, geological reserves determine the reservoir development plan, development methods and future means of improving oil recovery, and its uncertainty is the most important.

[0003] The existing methods for studying uncertainty in geological reserves of oil reservoirs mainly include two categories: conceptual analysis of geological reserve uncertainty factors and numerical calculation of uncertainty.

[0004] At present, conceptual analysis of geological reserve uncertainty factors generally provides directions for the next step of research by analyzing different influencing factors. For example, previous researchers proposed that sedimentary phase research has great uncertainty through uncertainty analysis of sedimentary phase distribution, which can have a great impact on geological reserves. However, this type of analysis only demonstrates uncertainty from a single aspect, without forming a systematic understanding, and also without quantifying the uncertainty of a certain aspect, which is difficult to meet the needs of research.

[0005] Some scholars have begun to try numerical calculation of uncertainty, and have given the final reserve distribution by changing the numerical uncertainty of geological reserve calculation variables. However, this process lacks sensitivity analysis of different geological factors, resulting in some geological variables with less influence participating in uncertainty research, while the truly important influencing factors are not fully reflected. At the same time, the existing research methods do not have a quality control process, making it difficult to ensure the reliability of the research results.

[0006] At present, there are relatively few studies on geological reserve uncertainty at home and abroad, and the methods are limited to conceptual analysis of different influencing factors of geological reserve uncertainty, or research on the impact of a single variable on geological reserves. At present, there is a lack of systematic and in-depth research methods for geological reserve uncertainty and result quality control processes. It is difficult to ensure the rationality of the analysis process, and the results of geological reserve uncertainty research are difficult to truly reflect the complex underground geological conditions.

[0007] Therefore, it is necessary to provide a method and device for studying the uncertainty of oil reservoir geological reserves, systematically study the uncertainty of oil reservoir geological reserves, improve the reliability and systematicness of the research results, and provide a solid foundation for oil and gas field exploration and development. Summary of the invention

[0008] In order to overcome the defects of the above-mentioned prior art, the purpose of the present invention is to provide a method and device for studying the uncertainty of oil reservoir geological reserves, systematically study the uncertainty of oil reservoir geological reserves, improve the reliability and systematicness of the research results, and provide a solid foundation for oil and gas field exploration and development.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A method for studying uncertainty of oil reservoir geological reserves, characterized by comprising:

[0011] Analyze structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty;

[0012] Conduct geological reserve sensitivity analysis based on the analysis results of various uncertainties;

[0013] Conduct geological reserve uncertainty analysis based on the analysis results of various uncertainties;

[0014] Calculate the uncertainty analysis quality control index and perform quality control on geological reserve uncertainty analysis.

[0015] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0016] Establish a structural model and calculate the depth errors of each well point in different layers;

[0017] According to the well distribution, the data distribution of depth error is calculated according to the strength of well control, and the standard deviation is calculated to draw the structural error standard deviation distribution map.

[0018] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0019] For pixel-based geological models, the uncertainty range of sedimentary facies ratios is determined based on sedimentary facies ratios and geological knowledge;

[0020] For the geological model based on the target sedimentary body, the uncertainty variation range of each geological parameter of the sedimentary body is determined based on geological knowledge.

[0021] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0022] Statistically interpret the porosity distribution of the reservoir through well logging and obtain the standard deviation of the porosity distribution;

[0023] The standard deviation of porosity distribution is taken as the uncertainty range of model porosity.

[0024] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0025] For wells drilled before the reservoir begins production or injection, calculate the average difference between the model water saturation and the log water saturation;

[0026] The average difference is taken as the uncertainty range of water saturation.

[0027] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0028] Select the sedimentary phase close to the oil-water interface, test the capillary pressure in the sedimentary phase and draw a curve;

[0029] According to the curve, the highest and lowest values ​​of the oil and gas starting filling height are selected as the uncertainty variation range of the oil-water interface.

[0030] In some embodiments of the present invention, when the oil-water interface is derived from pressure gradient calculation, the uncertainty variation range of the oil-water interface is calculated based on the uncertainty of the oil line and the water line in the pressure gradient map.

[0031] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0032] The maximum and minimum values ​​of the volume coefficient test results are selected as the uncertainty variation range of the volume coefficient.

[0033] In some embodiments of the present invention, a geological reserve sensitivity analysis is performed based on the analysis results of various uncertainties, including:

[0034] Calculate different construction realizations based on the construction error standard deviation distribution map;

[0035] According to the variation range of sedimentary phase proportion or sedimentary body geological parameter uncertainty, porosity uncertainty, water saturation uncertainty, oil-water interface uncertainty and volume coefficient uncertainty, Monte Carlo sampling is carried out in sequence, and reserve calculation is performed. The influence of different uncertainty parameters on geological reserves is statistically analyzed and ranked according to the influence size.

[0036] In some embodiments of the present invention, the uncertainty analysis of geological reserves is performed based on the analysis results of various uncertainties, including:

[0037] Select parameters with an uncertainty of more than 20% affecting geological reserves;

[0038] The range of uncertainty parameters is sampled by Monte Carlo, the geological reserves are calculated, and the uncertainty analysis of geological reserves is carried out to obtain the distribution histogram and cumulative probability distribution curve of geological reserves, and the geological reserves with cumulative probabilities of 10%, 50% and 90% are obtained.

[0039] In some embodiments of the present invention, quality control is performed on geological reserve uncertainty analysis, including:

[0040] Define the geological reserve uncertainty quality control index as Q,

[0041] Among them, P50 is the geological reserves corresponding to the cumulative probability of 50% in the cumulative probability distribution of geological reserves; Pi is the geological reserves calculated by the uncertainty analysis of geological reserves, and P10 <Pi<P90,

[0042] When Q<15%, the geological reserve uncertainty analysis results are judged to be correct;

[0043] When Q>15%, the geological reserve uncertainty analysis results are judged to be wrong, and the uncertainty analysis model and the original reserve calculation results are rechecked, and the geological reserve uncertainty analysis is repeated;

[0044] The distribution of geological reserves should conform to normal distribution or skewed distribution. When the reserve distribution is approximately uniform, the results of the geological reserve uncertainty analysis are judged to be unreasonable, and the uncertainty analysis model should be re-checked and the geological reserve uncertainty analysis should be re-conducted.

[0045] In a second aspect, the present invention discloses a device for studying uncertainty of oil reservoir geological reserves, comprising:

[0046] The construction uncertainty analysis unit is used to analyze the construction uncertainty and draw the standard deviation distribution map of the construction error;

[0047] Sedimentary facies uncertainty analysis unit, used to analyze sedimentary facies uncertainty and determine the uncertainty of sedimentary facies ratios or sedimentary body geological parameters;

[0048] Porosity uncertainty analysis unit, which analyzes porosity uncertainty and determines the standard deviation of porosity distribution;

[0049] The water saturation uncertainty analysis unit is used to analyze the water saturation uncertainty and determine the range of water saturation uncertainty;

[0050] Oil-water interface uncertainty analysis unit, used to analyze the uncertainty of the oil-water interface and determine the range of oil-water interface changes;

[0051] Volume coefficient uncertainty analysis unit, used to analyze the uncertainty of volume coefficient and determine the range of volume coefficient variation;

[0052] A geological reserve sensitivity analysis unit, used to perform geological reserve sensitivity analysis based on the analysis results of various uncertainties;

[0053] A geological reserve uncertainty analysis unit, used for performing geological reserve uncertainty analysis based on the analysis results of various uncertainties;

[0054] The analysis quality control unit is used to calculate the uncertainty analysis quality control coefficient and perform quality control on the geological reserve uncertainty analysis.

[0055] In a third aspect, the present invention discloses an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned method for studying uncertainty in geological reserves of oil reservoirs when executing the program.

[0056] In a fourth aspect, the present invention discloses a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the above-mentioned method for studying the uncertainty of geological reserves of oil reservoirs.

[0057] Technical effects and advantages of the present invention:

[0058] 1. The present invention conducts an in-depth and systematic sensitivity analysis of various parameters that affect the geological reserves of oil reservoirs, and simultaneously performs uncertainty analysis, which can relatively accurately grasp the uncertainty characteristics and ultimate impact.

[0059] 2. The present invention can verify the distribution of geological reserves of oil reservoirs by conducting uncertainty analysis, laying a good foundation for the selection of oil and gas field development methods and the preparation of development plans. At the same time, the method includes quality control of research results, making the understanding of uncertainty of geological reserves of oil reservoirs more reliable.

[0060] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 A flow chart of a method for studying uncertainty of oil reservoir geological reserves according to the present invention;

[0062] Figure 2 A distribution diagram of the standard deviation of the construction error of an embodiment of the present invention;

[0063] Figure 3 This is a sedimentary phase ratio uncertainty analysis diagram of an embodiment of the present invention;

[0064] Figure 4 is a reservoir porosity distribution histogram of an embodiment of the present invention;

[0065] Figure 5 A diagram showing the difference between the model saturation and the logging interpretation saturation in an embodiment of the present invention;

[0066] Figure 6 The capillary pressure curve of the dominant sedimentary phase near the oil-water interface of the embodiment of the present invention;

[0067] Figure 7 The uncertainty parameter sensitivity analysis result of geological reserves in the embodiment of the present invention;

[0068] Figure 8 This is the geological reserve uncertainty analysis result of the embodiment of the present invention. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0070] like Figure 1 As shown, the present invention provides a method for studying uncertainty of oil reservoir geological reserves, characterized by comprising:

[0071] Analyze structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty;

[0072] Conduct geological reserve sensitivity analysis based on the analysis results of various uncertainties;

[0073] Conduct geological reserve uncertainty analysis based on the analysis results of various uncertainties;

[0074] Calculate the uncertainty analysis quality control coefficient and perform quality control on geological reserve uncertainty analysis.

[0075] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0076] The blind measurement method was used to establish the structural model and the depth errors of each well point in different layers were counted;

[0077] According to the well distribution, the data distribution of depth error is calculated according to the strength of well control, and the standard deviation is calculated to draw the structural error standard deviation distribution map.

[0078] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0079] For pixel-based geological models, the uncertainty range of sedimentary facies ratios is determined based on sedimentary facies ratios and geological knowledge;

[0080] For the geological model based on the target sedimentary body, the uncertainty variation range of each geological parameter of the sedimentary body is determined based on geological knowledge.

[0081] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0082] Statistically interpret the porosity distribution of the reservoir through well logging and obtain the standard deviation of the porosity distribution;

[0083] The standard deviation of porosity distribution is taken as the uncertainty range of model porosity.

[0084] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0085] For wells drilled before the reservoir begins production or injection, calculate the average difference between the model water saturation and the log water saturation;

[0086] The average difference is taken as the uncertainty range of water saturation.

[0087] In some embodiments of the present invention, analyzing the oil-water interface uncertainty includes:

[0088] Select the sedimentary phase close to the oil-water interface, test the capillary pressure in the sedimentary phase and draw a curve;

[0089] According to the curve, the highest and lowest values ​​of the oil and gas starting filling height are selected as the uncertainty variation range of the oil-water interface.

[0090] In some embodiments of the present invention, when the oil-water interface is derived from pressure gradient calculation, the uncertainty variation range of the oil-water interface is calculated based on the uncertainty of the oil line and the water line in the pressure gradient map.

[0091] In some embodiments of the present invention, analyzing structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty includes:

[0092] Select the maximum and minimum values ​​of the volume coefficient test results as the uncertainty range of the volume coefficient

[0093] In some embodiments of the present invention, a geological reserve sensitivity analysis is performed based on the analysis results of various uncertainties, including:

[0094] Calculate different construction realizations based on the construction error standard deviation distribution map;

[0095] According to the variation range of sedimentary phase proportion or sedimentary body geological parameter uncertainty, porosity uncertainty, water saturation uncertainty, oil-water interface uncertainty and volume coefficient uncertainty, Monte Carlo sampling is carried out in sequence, and reserve calculation is performed. The influence of different uncertainty parameters on geological reserves is statistically analyzed and ranked according to the influence size.

[0096] In some embodiments of the present invention, the uncertainty analysis of geological reserves is performed based on the analysis results of various uncertainties, including:

[0097] Select parameters with an uncertainty of more than 20% affecting geological reserves;

[0098] The range of variation of each uncertainty parameter is sampled by Monte Carlo, the geological reserves are calculated, and the uncertainty analysis of geological reserves is carried out to obtain the distribution histogram and cumulative probability distribution curve of geological reserves, and the geological reserves with cumulative probabilities of 10%, 50% and 90% are obtained.

[0099] In some embodiments of the present invention, quality control is performed on geological reserve uncertainty analysis, including:

[0100] Define the geological reserve uncertainty quality control index as Q,

[0101] Among them, P50 is the geological reserves corresponding to the cumulative probability of 50% in the cumulative probability distribution of geological reserves; Pi is the geological reserves calculated by the uncertainty analysis of geological reserves, and P10 <Pi<P90,

[0102] Among them, P50 is the geological reserves corresponding to the cumulative probability of 50% in the cumulative probability distribution of geological reserves; Pi is the geological reserves calculated by the uncertainty analysis of geological reserves, and P10 <Pi<P90,

[0103] When Q<15%, the geological reserve uncertainty analysis results are judged to be correct;

[0104] When Q>15%, the geological reserve uncertainty analysis results are judged to be wrong, and the uncertainty analysis model and the original reserve calculation results are rechecked, and the geological reserve uncertainty analysis is repeated;

[0105] The distribution of geological reserves should conform to normal distribution or skewed distribution. When the reserve distribution is approximately uniform, the results of the geological reserve uncertainty analysis are judged to be unreasonable, and the uncertainty analysis model should be re-checked and the geological reserve uncertainty analysis should be re-conducted.

[0106] In a second aspect, the present invention discloses a device for studying uncertainty of oil reservoir geological reserves, comprising:

[0107] The construction uncertainty analysis unit is used to analyze the construction uncertainty and draw the standard deviation distribution map of the construction error;

[0108] Sedimentary facies uncertainty analysis unit, used to analyze sedimentary facies uncertainty and determine the uncertainty of sedimentary facies ratios or sedimentary body geological parameters;

[0109] Porosity uncertainty analysis unit, which analyzes porosity uncertainty and determines the standard deviation of porosity distribution;

[0110] The water saturation uncertainty analysis unit is used to analyze the water saturation uncertainty and determine the range of water saturation uncertainty;

[0111] Oil-water interface uncertainty analysis unit, used to analyze the uncertainty of the oil-water interface and determine the range of oil-water interface changes;

[0112] Volume coefficient uncertainty analysis unit, used to analyze the uncertainty of volume coefficient and determine the range of volume coefficient variation;

[0113] A geological reserve sensitivity analysis unit, used to perform geological reserve sensitivity analysis based on the analysis results of various uncertainties;

[0114] A geological reserve uncertainty analysis unit, used for performing geological reserve uncertainty analysis based on the analysis results of various uncertainties;

[0115] The analysis quality control unit is used to calculate the uncertainty analysis quality control coefficient and perform quality control on the geological reserve uncertainty analysis.

[0116] In a third aspect, the present invention discloses an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the steps of the above-mentioned method for studying the uncertainty of oil reservoir geological reserves are implemented.

[0117] In a fourth aspect, the present invention discloses a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method for studying the uncertainty of oil reservoir geological reserves. 。

[0118] In order to better illustrate the present solution, the following embodiments are also provided.

[0119] The method of the present invention is used to study the uncertainty of geological reserves of a carbonate oil reservoir.

[0120] S1: Analyze structural uncertainty and draw a distribution diagram of structural error standard deviation.

[0121] When the blind measurement method is used to calculate and establish the structural model, the depth error at each well point in different layers is calculated according to the distribution of wells and the degree of well control. The standard deviation of the depth error is calculated, and the distribution diagram of the structural error standard deviation is drawn, such as Figure 2 As shown in the figure, there are more oil wells in the middle of the study area, with stronger well point control, smaller structural uncertainty, and smaller standard deviation of structural error. However, at the edge of the study area, the well control is lower, the structural uncertainty is greater, and the standard deviation of structural error is larger.

[0122] S2: Analyze sedimentary facies uncertainty and determine the uncertainty of sedimentary facies proportions or geological parameters of sedimentary bodies.

[0123] For pixel-based geological models, such as Figure 3 As shown, according to the existing sedimentary phase ratio, the variation range of the sedimentary phase ratio is determined. Sedimentary phases 2 and 3 in the work area are adjacent phase belts, and their distribution in the work area is uncertain. Taking layer A as an example, the uncertainty variation range of the phase ratio of sedimentary phase 2 is positioned at + / -10%, while the uncertainty variation range of the phase ratio of sedimentary phase 3 is positioned at + / -5%.

[0124] S3: Analyze porosity uncertainty and determine the standard deviation of porosity distribution.

[0125] The porosity distribution of the reservoir is statistically analyzed, and the standard deviation of the porosity distribution is obtained as the porosity variation range of the model. Figure 4 This is the reservoir porosity distribution histogram of layer A. It is found that its standard deviation is 2.1% by statistics, so + / -2.1% is taken as the uncertainty range of porosity.

[0126] S4: Analyze the uncertainty of water saturation and determine the range of water saturation uncertainty.

[0127] For wells drilled before the start of production or injection in the reservoir, the average difference between the model water saturation and the water saturation of the logging curve is calculated as the uncertainty range of the water saturation. Figure 5The comparison bar chart of the model saturation and logging interpretation saturation of a certain oil well shows that for layer A, the average difference between the two is 10%, so + / -10% is used as the uncertainty range of porosity.

[0128] S5: Analyze the uncertainty of the oil-water interface and determine the range of variation of the oil-water interface.

[0129] A sedimentary phase with a wide distribution range near the oil-water interface was selected, the capillary pressure curve tested in the sedimentary phase was studied, the highest and lowest values ​​of the oil and gas starting filling height were selected, and the uncertainty variation range of the oil-water interface was determined. Figure 6 This is the capillary pressure diagram of the dominant sedimentary phase near the oil-water interface in layer A. It can be seen from the figure that the initial oil and gas filling height varies from 3 to 9 meters, with an average of 6 meters. Therefore, + / -3 meters is used as the uncertainty range of the oil-water interface.

[0130] S6: Analyze the uncertainty of volume coefficient and determine the range of volume coefficient variation.

[0131] According to the volume coefficient measurement results, the maximum and minimum values ​​are selected as the uncertainty range of the volume coefficient. According to the core test, the maximum value of the volume coefficient of the A layer is 2.34 and the minimum value is 1.98, so 1.98 to 2.34 is selected as the uncertainty range of the volume coefficient.

[0132] S7: Conduct geological reserve sensitivity analysis based on the analysis results of various uncertainties.

[0133] Different structural realizations are calculated based on the standard deviation distribution map of structural errors. For other uncertainty parameters (sedimentary phase uncertainty, porosity uncertainty, water saturation uncertainty, oil-water interface uncertainty and volume coefficient uncertainty), Monte Carlo sampling is used for each uncertainty parameter in turn according to different ranges of variation, and reserves calculation is performed to statistically analyze the impact of different uncertainty parameters on geological reserves. Figure 7 is the result of the sensitivity study of uncertain parameters of the reservoir. Figure 7 It can be seen that porosity is the most important parameter affecting geological reserves, followed by saturation, structure, oil-water interface and sedimentary phase ratio.

[0134] S8: Conduct geological reserve uncertainty analysis based on the analysis results of various uncertainties.

[0135] Select variables with large uncertainty (uncertainty parameters that affect geological reserves by more than 20%), including porosity, saturation, structure, oil-water interface and sedimentary phase ratio, and use Monte Carlo sampling for each variable according to the uncertainty range to calculate geological reserves and conduct geological reserve uncertainty analysis to obtain the distribution histogram and cumulative probability distribution of geological reserves, such as Figure 8As shown. At the same time, geological reserves with cumulative probabilities of 10%, 50% and 90% are obtained.

[0136] S9: Calculate the uncertainty analysis quality control index to conduct quality control on the uncertainty analysis of geological reserves.

[0137] The distribution of geological reserves conforms to a skewed distribution and is close to a normal distribution.

[0138] Define the geological reserve uncertainty quality control index as Q.

[0139] In the formula, P50 is the geological reserve corresponding to the cumulative probability of 50% in the cumulative probability distribution of geological reserves; Pi is the geological reserve calculated by the uncertainty analysis of geological reserves. Pi needs to satisfy P10 < Pi < P90.

[0140] After calculation, the quality control index Q of this oil reservoir is 8%, and P10 < Pi < P90. It is considered that the calculation result is reasonable and can reflect the uncertainty of the geological reserves of this oil reservoir.

[0141] In summary, the method of the present invention conducts in-depth and systematic sensitivity analysis on the various parameters affecting the geological reserves of the oil reservoir, and at the same time conducts uncertainty analysis, which can relatively accurately grasp the uncertainty characteristics and the final impact. On this basis, through uncertainty analysis, the distribution of the geological reserves of the oil reservoir can be determined, laying a good foundation for the selection of the oil and gas field development mode and the preparation of the development plan. At the same time, the method includes quality control of the research results, making the understanding of the uncertainty of the geological reserves of the oil reservoir more reliable.

[0142] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for studying uncertainty of oil reservoir geological reserves, characterized in that: include: Analyze structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty, and volume coefficient uncertainty; Conduct geological reserve sensitivity analysis based on the analysis results of various uncertainties; Conduct geological reserve uncertainty analysis based on the analysis results of various uncertainties; Calculate the uncertainty analysis quality control index and perform quality control on geological reserve uncertainty analysis.

2. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: Establish a structural model and calculate the depth errors of each well point in different layers; According to the well distribution, the data distribution of the depth error is calculated according to the strength of the well control, and the standard deviation is calculated to draw a structural error standard deviation distribution map.

3. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: For pixel-based geological models, the uncertainty range of sedimentary facies ratios is determined based on sedimentary facies ratios and geological knowledge; For the geological model based on the target sedimentary body, the uncertainty variation range of each geological parameter of the sedimentary body is determined based on geological knowledge.

4. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: Statistically interpret the porosity distribution of the reservoir through well logging and obtain the standard deviation of the porosity distribution; The porosity distribution standard deviation is taken as the uncertainty range of the model porosity.

5. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: For wells drilled before the reservoir begins production or injection, calculate the average difference between the model water saturation and the log water saturation; The average difference is taken as the uncertainty range of water saturation.

6. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: Selecting a sedimentary phase close to an oil-water interface, testing the capillary pressure in the sedimentary phase and drawing a curve; According to the curve, the highest and lowest values ​​of the oil and gas starting filling height are selected as the uncertainty variation range of the oil-water interface.

7. A method for studying uncertainty of oil reservoir geological reserves according to claim 6, characterized in that: When the oil-water interface is derived from the pressure gradient calculation, the uncertainty variation range of the oil-water interface is calculated based on the uncertainty of the oil line and water line in the pressure gradient map.

8. The method for studying uncertainty of oil reservoir geological reserves according to claim 1, characterized in that: The analytical structural uncertainty, sedimentary facies uncertainty, porosity uncertainty, water saturation uncertainty, oil-water contact uncertainty and volume coefficient uncertainty include: The maximum and minimum values ​​of the volume coefficient test results are selected as the uncertainty variation range of the volume coefficient.

9. A method for studying uncertainty of oil reservoir geological reserves according to any one of claims 1 to 8, characterized in that: The geological reserve sensitivity analysis based on the analysis results of various uncertainties includes: Calculate different construction realizations based on the construction error standard deviation distribution map; According to the variation range of sedimentary phase proportion or sedimentary body geological parameter uncertainty, porosity uncertainty, water saturation uncertainty, oil-water interface uncertainty and volume coefficient uncertainty, Monte Carlo sampling is carried out in sequence, and reserve calculation is performed. The influence of different uncertainty parameters on geological reserves is statistically analyzed and ranked according to the influence size.

10. The method for studying uncertainty of oil reservoir geological reserves according to claim 9, characterized in that: The uncertainty analysis of geological reserves based on the analysis results of various uncertainties includes: Select parameters with an uncertainty of more than 20% affecting geological reserves; The variation range of the uncertainty parameter is sampled by Monte Carlo, the geological reserves are calculated, and the uncertainty analysis of the geological reserves is performed to obtain the distribution histogram and cumulative probability distribution curve of the geological reserves, and the geological reserves with cumulative probabilities of 10%, 50% and 90% are obtained.

11. The method for studying uncertainty of oil reservoir geological reserves according to claim 10, characterized in that: The quality control of geological reserve uncertainty analysis includes: Define the geological reserve uncertainty quality control index as Q, Among them, P50 is the geological reserves corresponding to the cumulative probability of 50% in the cumulative probability distribution of geological reserves; Pi is the geological reserves calculated by the uncertainty analysis of geological reserves, and P10 <Pi<P90, When Q<15%, the geological reserve uncertainty analysis results are judged to be correct; When Q>15%, the geological reserve uncertainty analysis results are judged to be wrong, and the uncertainty analysis model and the original reserve calculation results are rechecked, and the geological reserve uncertainty analysis is re-performed; The distribution of geological reserves should conform to normal distribution or skewed distribution. When the reserve distribution is approximately uniform, the results of the geological reserve uncertainty analysis are judged to be unreasonable, and the uncertainty analysis model should be re-checked and the geological reserve uncertainty analysis should be re-conducted.

12. An oil reservoir geological reserve uncertainty research device, characterized in that: include: The construction uncertainty analysis unit is used to analyze the construction uncertainty and draw the standard deviation distribution map of the construction error; Sedimentary facies uncertainty analysis unit, used to analyze sedimentary facies uncertainty and determine the uncertainty of sedimentary facies ratios or sedimentary body geological parameters; Porosity uncertainty analysis unit, which analyzes porosity uncertainty and determines the standard deviation of porosity distribution; The water saturation uncertainty analysis unit is used to analyze the water saturation uncertainty and determine the range of water saturation uncertainty; Oil-water interface uncertainty analysis unit, used to analyze the uncertainty of the oil-water interface and determine the range of oil-water interface changes; Volume coefficient uncertainty analysis unit, used to analyze the uncertainty of volume coefficient and determine the range of volume coefficient variation; A geological reserve sensitivity analysis unit, used to perform geological reserve sensitivity analysis based on the analysis results of various uncertainties; A geological reserve uncertainty analysis unit, used for performing geological reserve uncertainty analysis based on the analysis results of various uncertainties; The analysis quality control unit is used to calculate the uncertainty analysis quality control coefficient and perform quality control on the geological reserve uncertainty analysis.

13. An electronic 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 program, the steps of a method for studying uncertainty of oil reservoir geological reserves as described in any one of claims 1-11 are implemented.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of a method for studying uncertainty of oil reservoir geological reserves as described in any one of claims 1 to 11 are implemented.

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