Rock fracture permeability calculation method and device, electronic equipment and storage medium

Abstract

The invention provides a rock fracture permeability calculation method and device, electronic equipment and a storage medium, and belongs to the technical field of oil-gas exploration and development. The method comprises the steps that the rock fracture average opening degree of a target interval is calculated according to imaging logging interpretation; analyzing and calculating the dynamic rock fracture opening degree of the target interval according to the pressure recovery well test; calculating a crack opening correction coefficient according to the rock crack average opening and the dynamic rock crack opening; and calculating the rock fracture permeability according to the fracture opening correction coefficient and the rock fracture density. According to the method, dynamic and static data such as imaging logging, pressure recovery well testing and testing are integrated, the crack opening correction coefficient is introduced, the rock crack permeability is calculated, and the rock crack permeability can be obtained more accurately.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, specifically to a method for calculating rock fracture permeability, a device for calculating rock fracture permeability, an electronic device, a machine-readable storage medium, and a computer program product. Background Technology

[0002] Reservoir permeability is a measure of the ability of fluids to pass through the effective pores of porous rocks under pressure differentials. Accurately determining reservoir permeability is an important task in reservoir evaluation.

[0003] Calculating fracture permeability has always been a challenge in reservoir evaluation. As seen in fractured reservoir engineering, in the simplified case of rock blocks with fractures parallel to the flow direction, the theoretical expression for fracture permeability is: , In the formula: K l The permeability of the crack; b 0 represents the width of the fracture opening. The above-mentioned theoretical model of fracture permeability differs significantly from actual formation testing. Without well testing for calibration, it can only be used to estimate the seepage capacity of fractures, but cannot quantitatively calculate fracture permeability, and therefore cannot accurately evaluate the seepage capacity of fractures in low-porosity, low-permeability fractured sandstone gas reservoirs. Current technologies rely on conventional logging and imaging logging to measure rock fracture parameters to calculate formation permeability. While imaging logging can accurately identify fractures, it only provides near-wellbore formation properties and cannot represent the overall formation characteristics. For fractured-vuggy reservoirs, which are characterized by numerous pores and fractures and strong heterogeneity, permeability cannot be analyzed solely based on logging data. Summary of the Invention

[0004] The purpose of this invention is to provide a method, apparatus, electronic device, and storage medium for calculating rock fracture permeability. This method integrates dynamic and static data from imaging logging, pressure recovery testing, and other tests, and introduces a fracture aperture correction coefficient to calculate rock fracture permeability, thereby obtaining rock fracture permeability more accurately.

[0005] To achieve the above objectives, the first aspect of the present invention provides a method for calculating the permeability of rock fractures, the method comprising: The average rock fracture aperture of the target section was calculated based on the interpretation of imaging logging. The dynamic rock fracture aperture of the target formation is calculated based on the pressure recovery well test analysis. Calculate the crack aperture correction coefficient based on the average crack aperture and dynamic crack aperture of the rock; Rock fracture permeability is calculated based on the fracture aperture correction factor and rock fracture density.

[0006] Based on the above technical means, by integrating dynamic and static data such as imaging logging, pressure recovery well testing, and other tests, and by introducing a fracture aperture correction coefficient, the permeability of rock fractures can be calculated more accurately.

[0007] In this embodiment of the application, calculating the average rock fracture aperture of the target section based on imaging logging interpretation includes: The parameter values ​​of each fracture in the target section are obtained based on the FMI imaging logging interpretation; The average opening of the rock fractures is calculated based on the parameter values ​​of each fracture.

[0008] Based on the above technical means, the static fracture parameter values ​​of the target section are obtained by interpreting FMI imaging logging, and the static rock fracture aperture is calculated.

[0009] In this embodiment of the application, the dynamic rock fracture aperture of the target formation is calculated based on pressure recovery well test analysis, including: Pressure recovery well test was conducted on the target formation to obtain the pressure recovery curve; Based on the pressure recovery curve, perform pressure-derivative curve fitting and pressure recovery semi-logarithmic curve fitting analysis; The dynamic fracture permeability is obtained from the slope of the curve representing the radial flow stage of the fracture in the semi-logarithmic curve of the pressure recovery. Calculate the dynamic rock fracture aperture based on the dynamic fracture permeability.

[0010] Based on the above technical means, the dynamic rock fracture opening can be obtained from the pressure recovery well test analysis.

[0011] In this embodiment of the application, calculating the dynamic rock fracture aperture based on fracture permeability includes: The dynamic rock fracture aperture is calculated by substituting the fracture permeability into the rock fracture permeability formula of a rock fracture model composed of multiple fractures.

[0012] In this embodiment of the application, the crack aperture correction coefficient is calculated based on the average rock crack aperture and the dynamic rock crack aperture, including: The ratio of dynamic rock fracture aperture to average rock fracture aperture is calculated as the fracture aperture correction coefficient.

[0013] In this embodiment of the application, the rock fracture permeability is calculated based on the fracture aperture correction coefficient and the rock fracture density, including: Substituting the fracture aperture correction factor into the rock fracture permeability calculation formula, the following rock fracture permeability calculation formula was obtained: ; in, For rock fracture permeability, Density of rock fractures For production, The viscosity of the liquid. This is the crude oil volume coefficient. The slope of the straight segment in the radial flow stage. The angle between the fracture system and the flow direction. This represents the aperture of each fracture obtained from imaging logging.

[0014] Based on the above technical methods, a formula for calculating rock fracture permeability was established, which can obtain rock fracture permeability more accurately.

[0015] A second aspect of this application provides a rock fracture permeability calculation device, the rock fracture permeability calculation device comprising: The average rock fracture aperture calculation unit is used to calculate the average rock fracture aperture of the target layer based on imaging logging interpretation. The dynamic rock fracture aperture calculation unit is used to calculate the dynamic rock fracture aperture of the target formation based on pressure recovery well test analysis. The crack aperture correction coefficient calculation unit is used to calculate the crack aperture correction coefficient based on the average crack aperture and dynamic crack aperture of the rock. The rock fracture permeability calculation unit calculates the rock fracture permeability based on the fracture aperture correction coefficient and the rock fracture density.

[0016] Based on the aforementioned technical means, this device integrates dynamic and static data from imaging logging, pressure recovery testing, and other tests, and introduces a fracture aperture correction coefficient to calculate rock fracture permeability, thereby obtaining rock fracture permeability more accurately.

[0017] A third aspect of this application provides an electronic device, comprising: The memory is configured to store instructions; and The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the rock fracture permeability calculation method.

[0018] A fourth aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the rock fracture permeability calculation method.

[0019] The fifth aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the rock fracture permeability calculation method.

[0020] The above-mentioned technical solution provides a method for calculating rock fracture permeability. By using FMI imaging logging data and pressure recovery well test data, a fracture permeability calculation model is established, which can accurately calculate rock fracture permeability and provide effective reservoir parameters for oil and gas reservoir development evaluation.

[0021] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0022] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of a method for calculating rock fracture permeability according to one embodiment of the present invention; Figure 2 This is a semi-logarithmic curve fitting diagram of a pressure recovery test well provided in one embodiment of the present invention; Figure 3 This is a simplified geological model diagram for calculating crack permeability provided by one embodiment of the present invention; Figure 4 This is a schematic diagram of the rock fracture permeability trend in well S67 provided by one embodiment of the present invention; Figure 5 This is a block diagram of a rock fracture permeability calculation device provided in one embodiment of the present invention. Detailed Implementation

[0023] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0024] Figure 1 This is a flowchart of a method for calculating rock fracture permeability according to one embodiment of the present invention. Figure 1 As shown, the method for calculating rock fracture permeability includes: S1: Calculate the average rock fracture aperture of the target section based on imaging logging interpretation.

[0025] In this embodiment of the application, calculating the average rock fracture aperture of the target section based on imaging logging interpretation includes: First, the parameter values ​​of each fracture in the target section are obtained based on the FMI imaging logging interpretation; then, the average rock fracture aperture is calculated based on the parameter values ​​of each fracture.

[0026] Imaging logging is a method of imaging physical parameters of the wellbore and surrounding objects based on observations of the geophysical field within the borehole. Formation MicroScanner Image (FMI) imaging logging uses formation microresistivity scanning imaging to capture these physical parameters.

[0027] In this embodiment, FMI imaging logging is used to acquire fracture aperture measurements and dip angles at different logging depths. Then, the target section for which rock fracture permeability needs to be calculated is determined as needed. Based on the depth of the target section, the fracture aperture measurements and dip angles corresponding to each rock fracture within that section are determined. Finally, the average rock fracture aperture is calculated based on the fracture aperture measurements corresponding to each rock fracture, using the following formula: (Formula 1) in, The average aperture of the rock fracture, in units of μm , The first in the current fracture system i The width of the crack, in units of μm Let i = 1, 2, ..., n, where n is the total number of rock fractures in the current fracture system. Static fracture parameter values ​​for the target interval are obtained based on FMI imaging logging interpretation, thereby calculating the static rock fracture aperture.

[0028] S2: Calculate the dynamic rock fracture aperture of the target section based on the pressure recovery well test analysis.

[0029] In this embodiment of the application, the dynamic rock fracture aperture of the target formation is calculated based on pressure recovery well test analysis, including: First, a pressure recovery test is performed on the target formation to obtain a pressure recovery curve. A pressure recovery test involves switching the well from a stable production state to a shut-in state and measuring the change in bottom hole pressure over time after shut-in, thereby studying the testing method for well and formation parameters. The pressure recovery curve is the curve showing the change in well pressure over time after shut-in; in this embodiment, the pressure recovery curve is the curve showing the change in pressure over time in the target formation.

[0030] Then, based on the pressure recovery curve, pressure-derivative curve fitting and pressure recovery semi-logarithmic curve fitting analysis are performed.

[0031] Then, the dynamic fracture permeability is obtained from the slope of the curve representing the radial flow stage of the fracture in the pressure-recovery semi-logarithmic curve. .

[0032] Finally, the dynamic rock fracture aperture is calculated based on the dynamic fracture permeability.

[0033] Based on the above technical means, the dynamic rock fracture opening can be obtained from the pressure recovery well test analysis.

[0034] In this embodiment of the application, calculating the dynamic rock fracture aperture based on fracture permeability includes: The dynamic rock fracture aperture is calculated by substituting the fracture permeability into the rock fracture permeability formula of a rock fracture model composed of multiple fractures.

[0035] In this embodiment of the application, the rock fracture permeability formula for a rock fracture model consisting of multiple fractures is shown in Formula 2: (Formula 2) in, Represents rock fracture permeability, in units of μm 2 , h The height of the rock stratum flow section, in meters. The angle between the first set of cracks and the flow direction is expressed in degrees. For the first group of cracks i The width of the crack, in units of μ m Let i = 1, 2, ..., n1, where n1 is the total number of rock fractures in the first group of fractures. The angle between the second set of cracks and the flow direction is expressed in degrees. For the second group of cracks, the first j The width of the crack, in units of μm j=1,2,...,n2, where n2 is the total number of rock fractures in the second group of fractures. For the first s The angle between the crack group and the flow direction, in degrees. For the first s The first group of cracks o The width of the crack, in units of μm o=1,2,...,n s n s For the first s The total number of rock fractures in the group of fractures.

[0036] In this embodiment, dynamic fracture permeability is obtained from the slope of the curve representing the radial flow stage of the fracture in the pressure-recovery semi-logarithmic curve. Substituting into Formula 2, the dynamic rock fracture aperture can be calculated.

[0037] S3: Calculate the crack opening correction coefficient based on the average crack opening and dynamic crack opening of the rock.

[0038] In this embodiment of the application, the crack aperture correction coefficient is calculated based on the average rock crack aperture and the dynamic rock crack aperture, including: The ratio of the dynamic rock fracture aperture to the average rock fracture aperture is calculated as the fracture aperture correction coefficient. The expression for the fracture aperture correction coefficient is as follows: (Formula 3) in, N This is the crack aperture correction factor. b g This refers to the dynamic rock fracture opening.

[0039] S4: Calculate the rock fracture permeability based on the fracture aperture correction coefficient and rock fracture density.

[0040] In this embodiment of the application, the rock fracture permeability is calculated based on the fracture aperture correction coefficient and the rock fracture density, including: Substituting the fracture aperture correction factor into the rock fracture permeability calculation formula, the following rock fracture permeability calculation formula was obtained: ; in, For rock fracture permeability, Density of rock fractures For production, The viscosity of the liquid. This is the crude oil volume coefficient. The slope of the straight segment in the radial flow stage. The angle between the fracture system and the flow direction. This represents the aperture of each fracture obtained from imaging logging.

[0041] Based on the above technical methods, a formula for calculating rock fracture permeability was established, which can obtain rock fracture permeability more accurately.

[0042] Based on the above technical means, by integrating dynamic and static data such as imaging logging, pressure recovery well testing, and other tests, and by introducing a fracture aperture correction coefficient, the permeability of rock fractures can be calculated more accurately.

[0043] The method of this application will be described below with reference to specific embodiments.

[0044] In this example, well S67 is an Ordovician carbonate reservoir in an oilfield. Its reservoir space is primarily composed of dissolution fractures and cavities, with uneven fracture development and strong heterogeneity. Core analysis and conventional logging data can only obtain formation properties near the wellbore. For fractured and cavitary reservoirs, it is difficult to obtain accurate data reflecting the reservoir development status using only static data. To more accurately calculate rock fracture permeability, this paper combines imaging logging data and well test results, introducing correction coefficients, to derive a formula for calculating reservoir rock fracture permeability.

[0045] First, the depth, aperture, and dip angle of each fracture in the target section are read according to the FMI imaging logging interpretation to calculate the average aperture of the rock fracture.

[0046] Table 1 shows the fracture aperture and dip angle parameters of each fracture in the study section obtained by imaging logging in well S67 of a certain oilfield.

[0047] Table 1

[0048] Then, a well test model was established, and pressure recovery well test analysis was performed on the fractured section to obtain dynamic fracture permeability. In one embodiment, the semi-logarithmic curve fitting diagram of the pressure recovery test is as follows: Figure 2 As shown in Table 2, the data represents the results of the pressure recovery test analysis for well S67.

[0049] Table 2 Interpretation of Pressure Recovery Test Results for Well S67

[0050] Then, dynamic crack penetration. The dynamic rock fracture aperture is obtained by substituting the fracture permeability formula into a simple rock fracture model consisting of multiple fractures.

[0051] like Figure 3 The figure shown is a simplified physical model for calculating fracture permeability according to an embodiment of this application. In this model, there are two sets of fractures, namely set A and set B. The fracture permeability formula obtained from this model is: (Formula 4) in, The angle between the cracks in group A and the flow direction is expressed in degrees. For the first i The width of the crack, in units of μ m Let i = 1, 2, ..., n1, where n1 is the total number of rock fractures in group A. The angle between the cracks in group B and the flow direction is expressed in degrees. The first crack in group B j The width of the crack, in units of μm j=1,2,...,n2, where n2 is the total number of rock fractures in group B.

[0052] Then, dynamic crack penetration. Substituting into Formula 4, we can obtain the formula for calculating the dynamic rock fracture aperture: ; in, For production, The viscosity of the liquid. This is the crude oil volume coefficient. The slope of the straight segment in the radial flow stage. The angle between the fracture system and the flow direction.

[0053] Then, combining static and dynamic data analysis, a crack aperture correction coefficient N is introduced, the expression of which is: .

[0054] Finally, the rock fracture permeability k is calculated by combining the fracture aperture correction coefficient and the rock fracture density, and its expression is as follows.

[0055] ; in, For rock fracture permeability, Density of rock fractures For production, The viscosity of the liquid. This is the crude oil volume coefficient. The slope of the straight segment in the radial flow stage. The angle between the fracture system and the flow direction. This represents the aperture of each fracture obtained from imaging logging.

[0056] The final fracture permeability calculation results are as follows: Figure 4 As shown.

[0057] This invention was used to calculate the fracture permeability of the rock fractures in the 5654-5674m section of the reservoir, which has a permeability of 9.76D. The fracture permeability k calculated using the correction factor was compared with the permeability k_f calculated using static data; their amplitude variations are basically consistent. The calculation formula of this application is accurate, and its fracture permeability calculation results are more precise.

[0058] The second aspect of this application provides a device for calculating the permeability of rock fractures, such as... Figure 5 As shown, the rock fracture permeability calculation device includes: The average rock fracture aperture calculation unit is used to calculate the average rock fracture aperture of the target layer based on imaging logging interpretation. The dynamic rock fracture aperture calculation unit is used to calculate the dynamic rock fracture aperture of the target formation based on pressure recovery well test analysis. The crack aperture correction coefficient calculation unit is used to calculate the crack aperture correction coefficient based on the average crack aperture and dynamic crack aperture of the rock. The rock fracture permeability calculation unit calculates the rock fracture permeability based on the fracture aperture correction coefficient and the rock fracture density.

[0059] Based on the aforementioned technical means, this device integrates dynamic and static data from imaging logging, pressure recovery testing, and other tests, and introduces a fracture aperture correction coefficient to calculate rock fracture permeability, thereby obtaining rock fracture permeability more accurately.

[0060] A third aspect of this application provides an electronic device, comprising: The memory is configured to store instructions; and The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the rock fracture permeability calculation method.

[0061] A fourth aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the rock fracture permeability calculation method.

[0062] The fifth aspect of this application provides a computer program product, including a computer program that, when executed by a processor, implements the rock fracture permeability calculation method.

[0063] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0064] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0065] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A method for calculating rock fracture permeability, characterized in that, The method for calculating rock fracture permeability includes: The average rock fracture aperture of the target section was calculated based on the interpretation of imaging logging. The dynamic rock fracture aperture of the target formation is calculated based on the pressure recovery well test analysis. Calculate the crack aperture correction coefficient based on the average crack aperture and dynamic crack aperture of the rock; Rock fracture permeability is calculated based on the fracture aperture correction factor and rock fracture density.

2. The method for calculating rock fracture permeability according to claim 1, characterized in that, The average rock fracture aperture of the target section is calculated based on imaging logging interpretation, including: The parameter values ​​of each fracture in the target section are obtained based on the FMI imaging logging interpretation; The average opening of the rock fractures is calculated based on the parameter values ​​of each fracture.

3. The method for calculating rock fracture permeability according to claim 1, characterized in that, The dynamic rock fracture aperture of the target formation is calculated based on pressure recovery well test analysis, including: Pressure recovery well test was conducted on the target formation to obtain the pressure recovery curve; Based on the pressure recovery curve, perform pressure-derivative curve fitting and pressure recovery semi-logarithmic curve fitting analysis; The dynamic fracture permeability is obtained from the slope of the curve representing the radial flow stage of the fracture in the semi-logarithmic curve of the pressure recovery. Calculate the dynamic rock fracture aperture based on the dynamic fracture permeability.

4. The method for calculating rock fracture permeability according to claim 3, characterized in that, Calculating dynamic rock fracture aperture based on fracture permeability includes: The dynamic rock fracture aperture is calculated by substituting the fracture permeability into the rock fracture permeability formula of a rock fracture model composed of multiple fractures.

5. The method for calculating rock fracture permeability according to claim 1, characterized in that, The crack aperture correction factor is calculated based on the average crack aperture and dynamic crack aperture of the rock, including: The ratio of dynamic rock fracture aperture to average rock fracture aperture is calculated as the fracture aperture correction coefficient.

6. The method for calculating rock fracture permeability according to claim 1, characterized in that, Rock fracture permeability is calculated based on the fracture aperture correction factor and rock fracture density, including: Substituting the fracture aperture correction coefficient into the rock fracture permeability calculation formula, we obtain the following rock fracture permeability calculation formula: ； in, For rock fracture permeability, Density of rock fractures For production, The viscosity of the liquid. This is the crude oil volume coefficient. The slope of the straight segment in the radial flow stage. The angle between the fracture system and the flow direction. This represents the aperture of each fracture obtained from imaging logging.

7. A device for calculating the permeability of rock fractures, characterized in that, The rock fracture permeability calculation device includes: The average rock fracture aperture calculation unit is used to calculate the average rock fracture aperture of the target layer based on imaging logging interpretation. The dynamic rock fracture aperture calculation unit is used to calculate the dynamic rock fracture aperture of the target formation based on pressure recovery well test analysis. The crack aperture correction coefficient calculation unit is used to calculate the crack aperture correction coefficient based on the average crack aperture and dynamic crack aperture of the rock. The rock fracture permeability calculation unit calculates the rock fracture permeability based on the fracture aperture correction coefficient and the rock fracture density.

8. An electronic device, characterized in that, include: The memory is configured to store instructions; as well as The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the rock fracture permeability calculation method according to any one of claims 1 to 6.

9. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the rock fracture permeability calculation method as described in any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the rock fracture permeability calculation method according to any one of claims 1 to 6.

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