Fracture effectiveness evaluation method, device and equipment based on conventional logging and medium

Abstract

The invention discloses a crack effectiveness evaluation method and device based on conventional logging, equipment and a medium. The method comprises the following steps: calculating a resistivity reduction coefficient based on a resistivity curve; calculating an increase value of the interval transit time curve based on the interval transit time curve and shale content correction; calculating a resistivity invasion amplitude difference value based on the deep lateral resistivity and the shallow lateral resistivity; based on the resistivity reduction coefficient, the increase value of the interval transit time curve and the resistivity invasion amplitude difference value, calculating a crack effective evaluation index; establishing a relationship chart of the test results of the research area and crack effectiveness evaluation indexes, and determining a threshold value of the crack effectiveness evaluation indexes; and comprehensively evaluating the radial direction and the longitudinal direction of the crack based on the effective evaluation index and the threshold value of the crack. Based on the resistivity reduction coefficient, the increase value of the interval transit time curve and the resistivity invasion amplitude difference value, the crack effectiveness evaluation index is calculated, the crack envelope surface evaluation technology is established, and crack effectiveness evaluation is carried out on the complex reservoir.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas geophysical exploration, and more specifically, to a fracture effectiveness evaluation method, device, equipment and medium based on conventional well logging. Background Art

[0002] Fractures are important in the study of oil and gas reservoirs as underground oil and gas storage spaces and channels for oil and gas migration. The effectiveness evaluation of fractures is the key to reservoir evaluation. Fractures have an important impact on oil and gas well fracturing and its productivity. Therefore, comprehensive and quantitative evaluation and prediction of fractures can improve the development effect of oil and gas reservoirs.

[0003] At present, the commonly used fracture evaluation methods include fracture observation and description based on cores, thin sections, and outcrops, fracture evaluation based on imaging logging and array acoustic logging, and fracture evaluation based on conventional logging. Cores are the most intuitive and effective means of identifying fractures, but due to the high risk and high cost of coring, it is impossible to directly evaluate the development of formation fractures through cores on a large scale. Imaging logging can determine the inclination and dip of fractures and calculate parameters such as the length, opening, and density of fractures, but imaging logging data is scarce and the cost is high. Array acoustic logging can identify fractures to a certain extent through the attenuation of acoustic wave amplitude, but the evaluation of fractures is limited to the qualitative level and the effect is very limited. Compared with other methods, fracture evaluation based on conventional logging has the advantages of low cost, practicality and economy.

[0004] In the prior art, a fracture cumulative aperture evaluation chart is produced based on a numerical simulation model of micro-spherical focused logging; a fracture cumulative aperture is obtained based on the fracture cumulative aperture evaluation chart; and fracture porosity and fracture density are obtained based on the fracture cumulative aperture. This technology establishes a method for evaluating the cumulative aperture, porosity, and density of fractures using micro-spherical focused logging, and uses micro-spherical focused logging and similar electrode system logging data to achieve quantitative fracture evaluation, providing an effective means for quantitative fracture evaluation. However, this method requires a large amount of micro-spherical focused logging data to carry out numerical simulation and produce fracture cumulative aperture evaluation charts. The operation is complex and the regional applicability is poor, making it difficult to promote widely.

[0005] In the identification of fractures in sandstone and mudstone profiles, An Fengquan et al. used microsphere, lateral, density, acoustic wave, and inclination logging to extract abnormal information of fractures, and used comprehensive discriminant function and neural network method to identify fractures; Zhang Long et al. used rough set theory and logging curve sample information related to fracture development, and used BP neural network to identify fractures; Tang Hong et al. calculated the probability of fracture existence based on core data and conventional logging data using curve element method, and established fracture probability model using sequential Gaussian method. However, the current fracture evaluation based on conventional logging can only identify fractures qualitatively, but cannot perform quantitative evaluation.

[0006] Therefore, it is necessary to develop a fracture effectiveness evaluation method, device, equipment and medium based on conventional well logging.

[0007] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0008] The present invention proposes a fracture effectiveness evaluation method, device, equipment and medium based on conventional well logging. Based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference, the fracture effectiveness evaluation index is calculated and a fracture envelope evaluation technology is established to evaluate the fracture effectiveness of complex reservoirs.

[0009] In a first aspect, an embodiment of the present disclosure provides a fracture effectiveness evaluation method based on conventional well logging, comprising:

[0010] Based on the resistivity curve, the resistivity reduction factor is calculated;

[0011] Based on the sonic time difference curve and the correction of the mud content, the increase value of the sonic time difference curve is calculated;

[0012] Calculating a resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity;

[0013] Calculating a fracture effectiveness evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference;

[0014] Establish a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determine the threshold value of the fracture effectiveness evaluation index in the study area;

[0015] Based on the crack effective evaluation index and the threshold value, a comprehensive evaluation is performed on the radial and longitudinal directions of the crack.

[0016] Preferably, the resistivity reduction coefficient is:

[0017]

[0018] In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

[0019] Preferably, the increase value of the acoustic wave time difference curve is:

[0020]

[0021] Where, ACSHFI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC base is the acoustic time difference baseline value, V sh The mud content.

[0022] Preferably, the resistivity intrusion amplitude difference is:

[0023] RDS FI =lg(RD-RS)

[0024] Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

[0025] Preferably, the crack effectiveness evaluation index is:

[0026] FIND=a×RDB FI +b×ACSH FI +c×RDS FI

[0027] Where FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

[0028] Preferably, based on the crack effective evaluation index and the threshold value, the comprehensive evaluation of the radial and longitudinal directions of the cracks includes:

[0029] Based on the crack effective evaluation index and the threshold value, a crack envelope surface evaluation model is established, and the envelope area comprehensive evaluation index is calculated to achieve radial and longitudinal comprehensive evaluation of the crack.

[0030] Preferably, the envelope area comprehensive evaluation index is:

[0031]

[0032] Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

[0033] In a second aspect, the embodiment of the present disclosure further provides a fracture effectiveness evaluation device based on conventional well logging, comprising:

[0034] A resistivity reduction coefficient calculation module calculates the resistivity reduction coefficient based on the resistivity curve;

[0035] The increase value calculation module of the acoustic time difference curve calculates the increase value of the acoustic time difference curve based on the acoustic time difference curve and the mud content correction;

[0036] A resistivity invasion amplitude difference calculation module is used to calculate the resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity;

[0037] A fracture effective evaluation index calculation module, which calculates a fracture effective evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference;

[0038] A threshold value determination module is used to establish a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determine the threshold value of the fracture effectiveness evaluation index of the study area;

[0039] The comprehensive evaluation module performs a comprehensive evaluation on the radial and longitudinal directions of the cracks based on the crack effective evaluation index and the threshold value.

[0040] Preferably, the resistivity reduction coefficient is:

[0041]

[0042] In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

[0043] Preferably, the increase value of the acoustic wave time difference curve is:

[0044]

[0045] Where, ACSH FI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC base is the acoustic time difference baseline value, V sh The mud content.

[0046] Preferably, the resistivity intrusion amplitude difference is:

[0047] RDS FI =lg(RD-RS)

[0048] Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

[0049] Preferably, the crack effectiveness evaluation index is:

[0050] FIND=a×RDB FI +b×ACSHFI +c×RDS FI

[0051] Where FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

[0052] Preferably, based on the crack effective evaluation index and the threshold value, the comprehensive evaluation of the radial and longitudinal directions of the cracks includes:

[0053] Based on the crack effective evaluation index and the threshold value, a crack envelope surface evaluation model is established, and the envelope area comprehensive evaluation index is calculated to achieve radial and longitudinal comprehensive evaluation of the crack.

[0054] Preferably, the envelope area comprehensive evaluation index is:

[0055]

[0056] Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

[0057] In a third aspect, an embodiment of the present disclosure further provides an electronic device, the electronic device comprising:

[0058] A memory storing executable instructions;

[0059] A processor runs the executable instructions in the memory to implement the conventional well logging-based fracture effectiveness evaluation method.

[0060] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the conventional logging-based fracture effectiveness evaluation method is implemented.

[0061] Its beneficial effects are:

[0062] Based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference, the fracture effectiveness evaluation index is calculated and the fracture envelope evaluation technology is established to evaluate the fracture effectiveness of complex reservoirs and improve the accuracy of effective fracture interpretation. The operation is simple and fast, the operability is strong, and the application range is wide, providing technical support for oil and gas well fracturing optimization and improvement of production capacity.

[0063] The methods and apparatus of the present invention have other features and advantages that will be apparent from, or will be described in detail in, the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0065] Figure 1 The flowchart shows the steps of a fracture effectiveness evaluation method based on conventional well logging according to an embodiment of the present invention.

[0066] Figure 2 A schematic diagram of a threshold value chart for determining a fracture effectiveness evaluation index in a study area according to an embodiment of the present invention is shown.

[0067] Figure 3 A schematic diagram showing evaluation results using a crack effectiveness evaluation technique according to an embodiment of the present invention is shown.

[0068] Figure 4 A schematic diagram showing the relationship between evaluation results and test yield according to an embodiment of the present invention.

[0069] Figure 5 A block diagram of a fracture effectiveness evaluation device based on conventional well logging according to an embodiment of the present invention is shown.

[0070] Description of reference numerals:

[0071] 201. Resistivity reduction coefficient calculation module; 202. Acoustic wave time difference curve increase value calculation module; 203. Resistivity intrusion amplitude difference calculation module; 204. Crack effective evaluation index calculation module; 205. Threshold value determination module; 206. Comprehensive evaluation module. DETAILED DESCRIPTION

[0072] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0073] The present invention provides a fracture effectiveness evaluation method based on conventional well logging, comprising:

[0074] Based on the resistivity curve, the resistivity reduction factor is calculated;

[0075] Based on the sonic time difference curve and the correction of the mud content, the increase value of the sonic time difference curve is calculated;

[0076] Based on the deep lateral resistivity and the shallow lateral resistivity, the resistivity invasion amplitude difference is calculated;

[0077] The effective evaluation index of the crack is calculated based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the difference in resistivity invasion amplitude;

[0078] Establish a relationship chart between the test results and the fracture effectiveness evaluation index in the study area, and determine the threshold value of the fracture effectiveness evaluation index in the study area;

[0079] Based on the crack effective evaluation index and threshold value, a comprehensive evaluation is performed on the radial and longitudinal directions of the cracks.

[0080] In one example, the resistivity reduction factor is:

[0081]

[0082] In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

[0083] In one example, the increase in the acoustic time difference curve is:

[0084]

[0085] Where, ACSH FI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC base is the acoustic time difference baseline value, V sh The mud content.

[0086] In one example, the resistivity intrusion magnitude difference is:

[0087] RDS FI =lg(RD-RS)

[0088] Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

[0089] In one example, the crack effectiveness evaluation index is:

[0090] FIND=a×RDB FI +b×ACSH FI +c×RDS FI

[0091] Where, FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

[0092] In one example, based on the crack effective evaluation index and the threshold value, the comprehensive evaluation of the radial and longitudinal directions of the cracks includes:

[0093] Based on the effective evaluation index and threshold value of cracks, a crack envelope surface evaluation model is established, and the comprehensive evaluation index of the envelope area is calculated to achieve radial and longitudinal comprehensive evaluation of cracks.

[0094] In one example, the envelope area comprehensive evaluation index is:

[0095]

[0096] Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

[0097] Specifically, based on the resistivity curve, the resistivity reduction coefficient is calculated; the larger the scale of fracture development, the lower the deep lateral absolute value is compared with the dense high-resistance background, and the farther it deviates from the baseline, the resistivity difference method is used to achieve this:

[0098]

[0099] In the formula, RDB FI is the resistivity reduction coefficient, Ω.m; RD base is the resistivity baseline value (the resistivity of the studied well section or the tight sandstone section or tight carbonate section of the adjacent well section is taken as the baseline value), Ω.m; RD is the deep lateral resistivity value, Ω.m.

[0100] Based on the correction of the acoustic time difference curve and the mud content, the increase value of the acoustic time difference curve is calculated; the acoustic time difference has basically no response to high-angle fractures, but it responds to low-angle fractures and caves, and its response characteristic is that the time difference curve appears to increase. On the basis of the correction of the formation mud content, the more developed the fracture, the more obvious the increase of the acoustic time difference value, and the farther it deviates from the baseline, so the acoustic difference method is used to calculate the increase value of the acoustic time difference:

[0101]

[0102] Where, ACSH FIis the increase value of the acoustic time difference, μs / ft; AC is the acoustic time difference value, μs / ft; AC base is the acoustic wave time difference baseline value (the acoustic wave time difference value of the studied well section or the tight sandstone layer section or tight carbonate layer section of the adjacent well section is taken as the baseline value), μs / ft; V sh is the mud content, %.

[0103] Based on the deep lateral resistivity and shallow lateral resistivity, the resistivity invasion amplitude difference is calculated; the occurrence of the fracture is directly related to the "difference" between the deep and shallow lateral directions, that is, for high-angle (generally above 75°) fractures, the dual lateral directions show a "positive difference"; for low-angle (generally below 60°) fractures, the dual lateral directions show a "negative difference"; for 60° to 75° fractures, the dual lateral differences are small or no difference; for 45° fractures, the dual lateral directions have a "negative difference" and the difference amplitude is the largest; the more developed the fracture, that is, the greater the fracture opening, fracture density, fracture porosity, and fracture radial extension depth, the greater the decrease in the dual lateral logging resistivity compared to the matrix rock resistivity. At the fracture, there is a certain amplitude difference between the deep and shallow lateral directions, but the amplitude difference is generally weak. In order to expand the amplitude difference, the resistivity invasion correction difference method is used to calculate the resistivity invasion amplitude difference:

[0104] RDS FI =lg(RD-RS)

[0105] Where, RDS FI is the resistivity intrusion amplitude difference, Ω.m; RD is the deep resistivity curve value, Ω.m; RS is the shallow resistivity curve value, Ω.m.

[0106] The effective evaluation index of the fracture is calculated based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference; based on RDB FI , ACSH FI and RDS FI , establish the calculation model of the crack effectiveness evaluation index (FIND):

[0107] FIND=a×RDB FI +b×ACSH FI +c×RDS FI

[0108] Where FIND is the fracture effectiveness evaluation index, a, b, and c are the weight coefficients corresponding to the resistivity reduction coefficient, the increase value of the acoustic time difference, and the resistivity invasion amplitude difference, respectively.

[0109] Establish a relationship chart between the test results in the study area and the crack effectiveness evaluation index, and determine the threshold value of the crack effectiveness evaluation index in the study area.

[0110] Based on the effective evaluation index of cracks, a crack envelope surface evaluation model is established, and the comprehensive evaluation index of the envelope area is calculated to achieve radial and longitudinal comprehensive evaluation of cracks:

[0111]

[0112] Where SF is the comprehensive evaluation index of the envelope area; FIND is the fracture effectiveness evaluation index, a decimal; depth1 is the starting depth of the fracture development section, m; depth2 is the ending depth of the fracture development section, m.

[0113] The present invention also provides a fracture effectiveness evaluation device based on conventional well logging, comprising:

[0114] A resistivity reduction coefficient calculation module calculates the resistivity reduction coefficient based on the resistivity curve;

[0115] The increase value calculation module of the acoustic time difference curve calculates the increase value of the acoustic time difference curve based on the acoustic time difference curve and the mud content correction;

[0116] The resistivity invasion amplitude difference calculation module calculates the resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity;

[0117] The fracture effective evaluation index calculation module calculates the fracture effective evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference;

[0118] The threshold value determination module establishes a relationship chart between the test results of the study area and the crack effectiveness evaluation index, and determines the threshold value of the crack effectiveness evaluation index in the study area;

[0119] The comprehensive evaluation module conducts a comprehensive evaluation of the radial and longitudinal directions of the cracks based on the crack effective evaluation index and threshold value.

[0120] In one example, the resistivity reduction factor is:

[0121]

[0122] In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

[0123] In one example, the increase in the acoustic time difference curve is:

[0124]

[0125] Where, ACSH FI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC baseis the acoustic time difference baseline value, V sh The mud content.

[0126] In one example, the resistivity intrusion magnitude difference is:

[0127] RDS FI =lg(RD-RS)

[0128] Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

[0129] In one example, the crack effectiveness evaluation index is:

[0130] FIND=a×RDB FI +b×ACS FI +c×RDS FI

[0131] Where, FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

[0132] In one example, based on the crack effective evaluation index and the threshold value, the comprehensive evaluation of the radial and longitudinal directions of the cracks includes:

[0133] Based on the effective evaluation index and threshold value of cracks, a crack envelope surface evaluation model is established, and the comprehensive evaluation index of the envelope area is calculated to achieve radial and longitudinal comprehensive evaluation of cracks.

[0134] In one example, the envelope area comprehensive evaluation index is:

[0135]

[0136] Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

[0137] Specifically, based on the resistivity curve, the resistivity reduction coefficient is calculated; the larger the scale of fracture development, the lower the deep lateral absolute value is compared with the dense high-resistance background, and the farther it deviates from the baseline, the resistivity difference method is used to achieve this:

[0138]

[0139] In the formula, RDB FIis the resistivity reduction coefficient, Ω.m; RD base is the resistivity baseline value (the resistivity of the studied well section or the tight sandstone section or tight carbonate section of the adjacent well section is taken as the baseline value), Ω.m; RD is the deep lateral resistivity value, Ω.m.

[0140] Based on the correction of the acoustic time difference curve and the mud content, the increase value of the acoustic time difference curve is calculated; the acoustic time difference has basically no response to high-angle fractures, but it responds to low-angle fractures and caves, and its response characteristic is that the time difference curve appears to increase. On the basis of the correction of the formation mud content, the more developed the fracture, the more obvious the increase of the acoustic time difference value, and the farther it deviates from the baseline, so the acoustic difference method is used to calculate the increase value of the acoustic time difference:

[0141]

[0142] Where, ACSH FI is the increase value of the acoustic time difference, μs / ft; AC is the acoustic time difference value, μs / ft; AC base is the acoustic wave time difference baseline value (the acoustic wave time difference value of the studied well section or the tight sandstone layer section or tight carbonate layer section of the adjacent well section is taken as the baseline value), μs / ft; V sh is the mud content, %.

[0143] Based on the deep lateral resistivity and shallow lateral resistivity, the resistivity invasion amplitude difference is calculated; the occurrence of the fracture is directly related to the "difference" between the deep and shallow lateral directions, that is, for high-angle (generally above 75°) fractures, the dual lateral directions show a "positive difference"; for low-angle (generally below 60°) fractures, the dual lateral directions show a "negative difference"; for 60° to 75° fractures, the dual lateral differences are small or no difference; for 45° fractures, the dual lateral directions have a "negative difference" and the difference amplitude is the largest; the more developed the fracture, that is, the greater the fracture opening, fracture density, fracture porosity, and fracture radial extension depth, the greater the decrease in the dual lateral logging resistivity compared to the matrix rock resistivity. At the fracture, there is a certain amplitude difference between the deep and shallow lateral directions, but the amplitude difference is generally weak. In order to expand the amplitude difference, the resistivity invasion correction difference method is used to calculate the resistivity invasion amplitude difference:

[0144] RDS FI =lg(RD-RS)

[0145] Where, RDS FI is the resistivity intrusion amplitude difference, Ω.m; RD is the deep resistivity curve value, Ω.m; RS is the shallow resistivity curve value, Ω.m.

[0146] The effective evaluation index of the fracture is calculated based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference; based on RDB FI , ACSH FIand RDS FI , establish the calculation model of the crack effectiveness evaluation index (FIND):

[0147] FIND=a×RDB FI +b×ACSH FI +c×RDS FI

[0148] Where FIND is the fracture effectiveness evaluation index, a, b, and c are the weight coefficients corresponding to the resistivity reduction coefficient, the increase value of the acoustic time difference, and the resistivity invasion amplitude difference, respectively.

[0149] Establish a relationship chart between the test results in the study area and the crack effectiveness evaluation index, and determine the threshold value of the crack effectiveness evaluation index in the study area.

[0150] Based on the effective evaluation index of cracks, a crack envelope surface evaluation model is established, and the comprehensive evaluation index of the envelope area is calculated to achieve radial and longitudinal comprehensive evaluation of cracks:

[0151]

[0152] Where SF is the comprehensive evaluation index of the envelope area; FIND is the fracture effectiveness evaluation index, a decimal; depth1 is the starting depth of the fracture development section, m; depth2 is the ending depth of the fracture development section, m.

[0153] The present invention also provides an electronic device, which includes: a memory storing executable instructions; and a processor, which runs the executable instructions in the memory to implement the above-mentioned fracture effectiveness evaluation method based on conventional well logging.

[0154] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the conventional well logging-based fracture effectiveness evaluation method is implemented.

[0155] To facilitate understanding of the solutions and effects of the embodiments of the present invention, four specific application examples are given below. Those skilled in the art should understand that the examples are only for facilitating understanding of the present invention, and any specific details thereof are not intended to limit the present invention in any way.

[0156] Example 1

[0157] Figure 1 The flowchart shows the steps of a fracture effectiveness evaluation method based on conventional well logging according to an embodiment of the present invention.

[0158] like Figure 1As shown, the fracture effectiveness evaluation method based on conventional logging includes: step 101, calculating the resistivity reduction coefficient based on the resistivity curve; step 102, calculating the increase value of the acoustic time difference curve based on the acoustic time difference curve and the mud content correction; step 103, calculating the resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity; step 104, calculating the fracture effectiveness evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference; step 105, establishing a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determining the threshold value of the fracture effectiveness evaluation index in the study area; step 106, based on the fracture effectiveness evaluation index and the threshold value, performing a comprehensive evaluation on the radial and longitudinal directions of the fracture.

[0159] This study takes the evaluation of the effectiveness of fractures in tight sandstone reservoirs in the core well M5 in northern Sichuan as an example. The empirical coefficients of the Malubei area are determined by imaging logging calibration: a = 0.437, b = 0.259, c = 0.198. Therefore, the calculation model for the evaluation index of the effectiveness of fractures in tight sandstone reservoirs in northeastern Sichuan is:

[0160] FIND=0.437×RDB FI +0.259×ACSH FI +0.198×RDS FI

[0161] Figure 2 A schematic diagram of a threshold value chart for determining a fracture effectiveness evaluation index in a study area according to an embodiment of the present invention is shown.

[0162] Based on the test results in northern Sichuan, a relationship chart between the test output and the fracture effectiveness evaluation index in northern Sichuan was established. Figure 2 As shown in Figure 2, the threshold value of the fracture effectiveness evaluation index in northern Sichuan is determined to be 0.05.

[0163] Figure 3 A schematic diagram showing evaluation results using a crack effectiveness evaluation technique according to an embodiment of the present invention is shown.

[0164] Figure 4 A schematic diagram showing the relationship between evaluation results and test yield according to an embodiment of the present invention.

[0165] This method was used to evaluate the fracture effectiveness of the tight sandstone reservoir in Well M5. The evaluation results are as follows: Figure 3The fracture effectiveness evaluation index of the well in the 5099m-5117m section is 0.08 (the lower limit of the fracture effectiveness evaluation index is 0.05, which is determined based on the imaging data and test results in the area), and the envelope area comprehensive evaluation index is 10.1, with large-scale fractures. FMI imaging logging shows 9 fractures with larger widths, and high-conductivity fractures are more developed, which matches the evaluation results. At the same time, the test production of this section is 211,700 cubic meters per day, which is in good agreement with the evaluation results. This method was applied to the other 8 test wells at the same time. The results are shown in Table 1, and the relationship between the comprehensive evaluation index of the envelope area and the test production is obtained, as shown in Table 1. Figure 4 shown.

[0166] Table 1

[0167]

[0168] from Figure 4 It can be seen that there is a positive correlation between the comprehensive evaluation index of the envelope area and the production. The larger the comprehensive evaluation index of the envelope area, the higher the test production, which further verifies the accuracy of the fracture effectiveness evaluation technology, provides strong support for gas testing and geological research, and improves production capacity. It has strong promotion in the study area, has great practical application value, and has good promotion and application prospects.

[0169] Example 2

[0170] Figure 5 A block diagram of a fracture effectiveness evaluation device based on conventional well logging according to an embodiment of the present invention is shown.

[0171] like Figure 5 As shown, the fracture effectiveness evaluation device based on conventional well logging includes:

[0172] A resistivity reduction coefficient calculation module 201 calculates the resistivity reduction coefficient based on the resistivity curve;

[0173] The increase value calculation module 202 of the acoustic time difference curve calculates the increase value of the acoustic time difference curve based on the acoustic time difference curve and the mud content correction;

[0174] The resistivity invasion amplitude difference calculation module 203 calculates the resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity;

[0175] A fracture effective evaluation index calculation module 204 calculates a fracture effective evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference;

[0176] The threshold value determination module 205 establishes a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determines the threshold value of the fracture effectiveness evaluation index of the study area;

[0177] The comprehensive evaluation module 206 performs a comprehensive evaluation on the radial and longitudinal directions of the cracks based on the crack effective evaluation index and the threshold value.

[0178] As an alternative, the resistivity reduction factor is:

[0179]

[0180] In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

[0181] As an alternative, the increase in the acoustic time difference curve is:

[0182]

[0183] Where, ACSH FI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC base is the acoustic time difference baseline value, V sh The mud content.

[0184] As an alternative, the resistivity intrusion amplitude difference is:

[0185] RDS FI =lg(RD-RS)

[0186] Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

[0187] As an optional solution, the crack effective evaluation index is:

[0188] FIND=a×RDB FI +b×ACSH FI +c×RDS FI

[0189] Where FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

[0190] As an optional solution, based on the crack effective evaluation index and threshold value, a comprehensive evaluation of the radial and longitudinal directions of the cracks includes:

[0191] Based on the effective evaluation index and threshold value of cracks, a crack envelope surface evaluation model is established, and the comprehensive evaluation index of the envelope area is calculated to achieve radial and longitudinal comprehensive evaluation of cracks.

[0192] As an optional solution, the comprehensive evaluation index of the envelope area is:

[0193]

[0194] Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

[0195] Example 3

[0196] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; and a processor, which runs the executable instructions in the memory to implement the above-mentioned fracture effectiveness evaluation method based on conventional well logging.

[0197] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0198] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0199] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0200] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0201] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0202] Example 4

[0203] An embodiment of the present disclosure provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the conventional well logging-based fracture effectiveness evaluation method is implemented.

[0204] According to the computer-readable storage medium of the embodiment of the present disclosure, non-transitory computer-readable instructions are stored thereon. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of each embodiment of the present disclosure are executed.

[0205] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0206] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any given examples.

[0207] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A fracture effectiveness evaluation method based on conventional well logging, characterized in that: include: Based on the resistivity curve, the resistivity reduction factor is calculated; Based on the sonic time difference curve and the correction of the mud content, the increase value of the sonic time difference curve is calculated; Calculating a resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity; Calculating a crack effective evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference; Establish a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determine the threshold value of the fracture effectiveness evaluation index in the study area; Based on the crack effective evaluation index and the threshold value, a comprehensive evaluation is performed on the radial and longitudinal directions of the crack.

2. The fracture effectiveness evaluation method based on conventional well logging according to claim 1, wherein: The resistivity reduction factor is: In the formula, RDB FI is the resistivity reduction factor, RD base is the resistivity baseline value, and RD is the deep lateral resistivity value.

3. The fracture effectiveness evaluation method based on conventional well logging according to claim 1, wherein: The increase value of the acoustic time difference curve is: Where, ACSH FI is the increase value of the sound wave time difference, AC is the sound wave time difference value, AC base is the acoustic time difference baseline value, V sh The mud content.

4. The fracture effectiveness evaluation method based on conventional well logging according to claim 1, wherein: The resistivity intrusion amplitude difference is: RDS FI =lg(RD-RS) Where, RDS FI is the resistivity intrusion amplitude difference, RD is the deep resistivity curve value, and RS is the shallow resistivity curve value.

5. The fracture effectiveness evaluation method based on conventional well logging according to claim 1, wherein: The crack effective evaluation index is: FIND=a×RDB FI +b×ACSH FI +c×RDS FI Where FIND is the crack effectiveness evaluation index, RDB FI is the resistivity reduction factor, ACSH FI RDS is the increase in the sound wave time difference. FI is the resistivity intrusion amplitude difference, a, b, c are the resistivity reduction coefficient, the increase value of the acoustic wave time difference, and the weight coefficient corresponding to the resistivity intrusion amplitude difference, respectively.

6. The fracture effectiveness evaluation method based on conventional well logging according to claim 1, wherein: Based on the crack effective evaluation index and the threshold value, a comprehensive evaluation of the radial and longitudinal directions of the cracks includes: Based on the crack effective evaluation index and the threshold value, a crack envelope surface evaluation model is established, and the envelope area comprehensive evaluation index is calculated to achieve radial and longitudinal comprehensive evaluation of the crack.

7. The fracture effectiveness evaluation method based on conventional well logging according to claim 6, wherein: The envelope area comprehensive evaluation index is: Where SF is the comprehensive evaluation index of the envelope area, FIND is the fracture effectiveness evaluation index, depth1 is the starting depth of the fracture development section, and depth2 is the ending depth of the fracture development section.

8. A fracture effectiveness evaluation device based on conventional well logging, characterized in that: include: A resistivity reduction coefficient calculation module calculates the resistivity reduction coefficient based on the resistivity curve; The increase value calculation module of the acoustic time difference curve calculates the increase value of the acoustic time difference curve based on the acoustic time difference curve and the mud content correction; A resistivity invasion amplitude difference calculation module is used to calculate the resistivity invasion amplitude difference based on the deep lateral resistivity and the shallow lateral resistivity; A fracture effective evaluation index calculation module, which calculates a fracture effective evaluation index based on the resistivity reduction coefficient, the increase value of the acoustic time difference curve and the resistivity invasion amplitude difference; A threshold value determination module is used to establish a relationship chart between the test results of the study area and the fracture effectiveness evaluation index, and determine the threshold value of the fracture effectiveness evaluation index of the study area; The comprehensive evaluation module performs a comprehensive evaluation on the radial and longitudinal directions of the cracks based on the crack effective evaluation index and the threshold value.

9. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the fracture effectiveness evaluation method based on conventional well logging as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the conventional well logging-based fracture effectiveness evaluation method described in any one of claims 1 to 7 is implemented.

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