Method and device for calculating gas saturation, electronic equipment and medium

Abstract

The application discloses a gas saturation calculation method, an electronic device and a medium. The method can comprise: determining a plurality of sample depths and corresponding gas saturations; calculating a complex wave impedance corresponding to each sample depth; establishing a fitting formula about the complex wave impedance and the gas saturation according to the gas saturation and the complex wave impedance corresponding to each sample depth; calculating the complex wave impedance of a target position, and then calculating the gas saturation corresponding to the target position through the fitting formula. The application quantitatively calculates the gas saturation of a pore space while considering the change of a skeleton mineral composition in the longitudinal direction through the complex wave impedance.

Description

Technical Field

[0001] This invention relates to the fields of oil and gas exploration and development, and geophysics, and more specifically, to a method for calculating gas saturation, an electronic device, and a medium. Background Technology

[0002] In shale gas exploration and development, gas saturation is one of the important parameters of the reservoir. Resistivity is the main logging method for determining water saturation in conventional sandstone reservoirs. However, the complex mineral composition and pore structure of shale reservoirs, and the inability to accurately express the quantitative influence of mineral composition and pore structure on resistivity, make it extremely difficult to determine water saturation using resistivity.

[0003] Existing technologies include:

[0004] 1. By constructing a conductivity model for marine shale, the influence of organic matter on the resistivity of marine shale is first stripped away, then the influence of low-resistivity thin layers is stripped away, the resistivity of high-resistivity layers after stripping away the influence of pyrite is calculated, and finally the influence of clay and formation water is considered. This establishes a gas saturation evaluation model for marine shale based on the gradual stripping of conductivity factors, and is used to evaluate the gas saturation of marine shale. This method is suitable for marine shale with diverse conductive components and conduction modes, and the fourth step requires establishing a three-dimensional digital core to determine the pyrite content, making the principle quite complex. Continental shale reservoirs exhibit strong vertical heterogeneity and rapid changes in mineral composition; therefore, this method is not applicable to the evaluation of water saturation in continental shale reservoirs.

[0005] 2. Using the Gassmann equation, the relationships between porosity and saturation and P-wave velocity, S-wave velocity, medium density, and the ratio of P-wave to S-wave velocity were calculated and analyzed. This was done with the bulk moduli of the rock matrix, water, and hydrocarbons (denoted as k). s k w k h ) and density (denoted as ρ) s ρ w ρ h Given the Poisson's ratio σ of the dry rock, the pore bulk modulus k is calculated. p Then, the porosity Φ and water saturation S are calculated sequentially. w The relationship between sandstone parameters and porosity and saturation of medium-oil-gas ratio and high-oil-gas ratio crude oil was explored. Contours of the P-wave velocity, P-wave impedance, and velocity ratio of sandstone as a function of porosity and saturation were presented, but no specific application examples were found.

[0006] Furthermore, the Gassmann theory makes the following assumptions: ① the rock is homogeneous; ② the fluid in the pores is tightly adhered to the pore walls; ③ gas and liquid are uniformly distributed in the pores; ④ the fluid in the pores does not affect the shear modulus; ⑤ the pores are spherical. These assumptions are difficult to meet in shale gas reservoirs, therefore they are not applicable to saturation calculations in shale gas reservoirs.

[0007] 3. Further reduce the fluid terms in the generalized elastic impedance equation to a formula containing the fluid term f from the Gassmann equation, and then invert to obtain the parameters f / v. S This parameter is a novel fluid identification factor, which is highly sensitive to fluid identification and improves the fluid identification capability of tight reservoirs. In this paper, 'f' represents a comprehensive expression of fluid and porosity terms, used for qualitative fluid identification in tight sandstone reservoirs; however, quantitative calculation of gas saturation in shale reservoirs still presents certain challenges.

[0008] Therefore, it is necessary to develop a method, electronic device and medium for calculating gas saturation based on composite wave impedance.

[0009] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0010] This invention proposes a method, electronic device, and medium for calculating gas saturation, which can quantitatively determine the gas saturation of pore space by considering the longitudinal variation of skeleton mineral composition through composite wave impedance.

[0011] In a first aspect, embodiments of this disclosure provide a method for calculating gas saturation, including:

[0012] Determine the depth of multiple samples and their corresponding gas saturation;

[0013] Calculate the composite wave impedance corresponding to each sample depth;

[0014] Based on the gas saturation and composite wave impedance corresponding to each sample depth, a fitting formula for composite wave impedance and gas saturation is established.

[0015] Calculate the composite wave impedance at the target location, and then calculate the gas saturation corresponding to the target location using the fitting formula.

[0016] Preferably, calculating the composite wave impedance corresponding to each sample depth includes:

[0017] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging.

[0018] The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively.

[0019] The composite wave impedance is calculated based on the longitudinal wave velocity and the transverse wave velocity.

[0020] Preferably, calculating the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity includes:

[0021] Calculate the longitudinal wave impedance and the transverse wave impedance based on the longitudinal wave velocity and the transverse wave velocity, respectively.

[0022] The composite wave impedance is calculated based on the longitudinal wave impedance and the transverse wave impedance.

[0023] Preferably, the longitudinal wave impedance is calculated using formula (1):

[0024] AI = C1*v p *DEN (1)

[0025] Where AI is the longitudinal wave impedance, v p Where is the longitudinal wave velocity, C1 is the calculation coefficient, and DEN is the volume density.

[0026] Preferably, the transverse wave impedance is calculated using formula (2):

[0027] SI = C2*v s *DEN (2)

[0028] Where SI is the transverse wave impedance, v s C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

[0029] Preferably, the composite wave impedance is calculated using formula (3):

[0030] CI = v p *(AI+SI) / 2 (3)

[0031] Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p The velocity is the longitudinal wave velocity.

[0032] Preferably, the fitting formula for the composite wave impedance and gas saturation is as follows:

[0033] S g =1-a*CI-b (4)

[0034] Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

[0035] As one specific implementation of this disclosure,

[0036] Secondly, embodiments of this disclosure also provide a gas saturation calculation device, comprising:

[0037] The data preparation module determines the depth of multiple samples and their corresponding gas saturation.

[0038] The composite wave impedance calculation module calculates the composite wave impedance corresponding to each sample depth.

[0039] The fitting module establishes a fitting formula for the composite wave impedance and the gas saturation based on the gas saturation and the composite wave impedance corresponding to each sample depth.

[0040] The gas saturation calculation module calculates the composite wave impedance at the target location, and then calculates the gas saturation corresponding to the target location using the fitting formula.

[0041] Preferably, calculating the composite wave impedance corresponding to each sample depth includes:

[0042] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging.

[0043] The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively.

[0044] The composite wave impedance is calculated based on the longitudinal wave velocity and the transverse wave velocity.

[0045] Preferably, calculating the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity includes:

[0046] Calculate the longitudinal wave impedance and the transverse wave impedance based on the longitudinal wave velocity and the transverse wave velocity, respectively.

[0047] The composite wave impedance is calculated based on the longitudinal wave impedance and the transverse wave impedance.

[0048] Preferably, the longitudinal wave impedance is calculated using formula (1):

[0049] AI = C1 * v p *DEN (1)

[0050] Where AI is the longitudinal wave impedance, v p Where is the longitudinal wave velocity, C1 is the calculation coefficient, and DEN is the volume density.

[0051] Preferably, the transverse wave impedance is calculated using formula (2):

[0052] SI = C2 * v s *DEN (2)

[0053] Where SI is the transverse wave impedance, vs C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

[0054] Preferably, the composite wave impedance is calculated using formula (3):

[0055] CI = v p *(AI+SI) / 2 (3)

[0056] Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p The velocity is the longitudinal wave velocity.

[0057] Preferably, the fitting formula for the composite wave impedance and gas saturation is as follows:

[0058] S g =1-a*CI-b (4)

[0059] Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

[0060] Thirdly, embodiments of this disclosure also provide an electronic device, the electronic device comprising:

[0061] Memory, which stores executable instructions;

[0062] A processor that executes the executable instructions in the memory to implement the gas saturation calculation method.

[0063] Fourthly, embodiments of this disclosure also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the gas saturation calculation method.

[0064] Its beneficial effects are as follows:

[0065] By avoiding the influence of complex lithology and diverse rock mineral composition in the formation, the composite wave impedance method takes into account both the changes in gas saturation in the pore space and the changes in the composition of the framework minerals. This avoids the limitations of resistivity logging methods or total organic carbon (TOC) methods, which are affected by factors other than pore fluids, and improves applicability.

[0066] The methods and apparatus of the present invention have other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0067] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same parts.

[0068] Figure 1 A flowchart illustrating the steps of a method for calculating gas saturation according to an embodiment of the present invention is shown.

[0069] Figure 2 A schematic diagram of the water saturation calculation results of well Y2 according to an embodiment of the present invention is shown.

[0070] Figure 3 A comparison diagram of gas saturation from well logging calculations and core analysis of well Y2 according to an embodiment of the present invention is shown.

[0071] Figure 4 A block diagram of a gas saturation calculation device according to an embodiment of the present invention is shown.

[0072] Explanation of reference numerals in the attached figures:

[0073] 201. Data Preparation Module; 202. Composite Wave Impedance Calculation Module; 203. Fitting Module; 204. Gas Saturation Calculation Module. Detailed Implementation

[0074] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0075] This invention provides a method for calculating gas saturation, comprising:

[0076] Determine the depth of multiple samples and their corresponding gas saturation; specifically, establish a gas saturation model to obtain first-hand data (Dep). i S gi ), Dep is the sample depth, S g Let i be the gas saturation, i = 1, 2, ..., N, where N is the number of samples for analyzing gas saturation.

[0077] Calculate the composite wave impedance corresponding to each sample depth; in one example, calculating the composite wave impedance corresponding to each sample depth includes:

[0078] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging.

[0079] The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively.

[0080] Calculate the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity.

[0081] In one example, calculating the composite wave impedance based on the P-wave velocity and S-wave velocity includes:

[0082] Calculate the longitudinal wave impedance and transverse wave impedance based on the longitudinal wave velocity and transverse wave velocity, respectively.

[0083] Calculate the composite wave impedance based on the longitudinal wave impedance and the transverse wave impedance.

[0084] In one example, the longitudinal wave impedance is calculated using formula (1):

[0085] AI = C1 * v p *DEN (1)

[0086] Where AI is the longitudinal wave impedance, v p Where is the longitudinal wave velocity, C1 is the calculation coefficient, and DEN is the volume density.

[0087] In one example, the transverse wave impedance is calculated using formula (2):

[0088] SI = C2 * v s *DEN (2)

[0089] Where SI is the transverse wave impedance, v s C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

[0090] In one example, the composite wave impedance is calculated using formula (3):

[0091] CI = v p *(AI+ SI) / 2 (3)

[0092] Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p The velocity is the longitudinal wave velocity.

[0093] Specifically, the longitudinal wave time difference, transverse wave time difference, and volume density of conventional logging are extracted from the corresponding depth acoustic wave train logging. The corresponding longitudinal wave velocity and transverse wave velocity are calculated by the longitudinal wave time difference and transverse wave time difference, respectively. Based on the longitudinal wave velocity and transverse wave velocity, the longitudinal wave impedance and transverse wave impedance are calculated by formulas (1) and (2), respectively. Based on the longitudinal wave impedance and transverse wave impedance, the composite wave impedance is calculated by formula (3).

[0094] Based on the gas saturation and composite wave impedance corresponding to each sample depth, a fitting formula for the composite wave impedance and gas saturation is established; in one example, the fitting formula for the composite wave impedance and gas saturation is:

[0095] Sg =1-a*CI-b (4)

[0096] Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

[0097] Specifically, based on the gas saturation and composite wave impedance corresponding to each sample depth, a fitting formula for composite wave impedance and gas saturation is established as formula (4).

[0098] The composite wave impedance at the target location is calculated, and then the gas saturation at the target location is calculated using a fitting formula.

[0099] The present invention also provides a gas saturation calculation device, comprising:

[0100] The data preparation module determines the depth of multiple samples and their corresponding gas saturation; specifically, it establishes a gas saturation model to obtain first-hand data (Dep). i S gi ), Dep is the sample depth, S g Let i be the gas saturation, i = 1, 2, ..., N, where N is the number of samples for analyzing gas saturation.

[0101] The composite wave impedance calculation module calculates the composite wave impedance corresponding to each sample depth. In one example, the calculation of the composite wave impedance corresponding to each sample depth includes:

[0102] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging.

[0103] The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively.

[0104] Calculate the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity.

[0105] In one example, calculating the composite wave impedance based on the P-wave velocity and S-wave velocity includes:

[0106] Calculate the longitudinal wave impedance and transverse wave impedance based on the longitudinal wave velocity and transverse wave velocity, respectively.

[0107] Calculate the composite wave impedance based on the longitudinal wave impedance and the transverse wave impedance.

[0108] In one example, the longitudinal wave impedance is calculated using formula (1):

[0109] AI = C1 * v p *DEN (1)

[0110] Where AI is the longitudinal wave impedance, v pWhere is the longitudinal wave velocity, C1 is the calculation coefficient, and DEN is the volume density.

[0111] In one example, the transverse wave impedance is calculated using formula (2):

[0112] SI = C2 * v s *DEN (2)

[0113] Where SI is the transverse wave impedance, v s C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

[0114] In one example, the composite wave impedance is calculated using formula (3):

[0115] CI = v p *(AI+SI) / 2 (3)

[0116] Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p The velocity is the longitudinal wave velocity.

[0117] Specifically, the longitudinal wave time difference, transverse wave time difference, and volume density of conventional logging are extracted from the corresponding depth acoustic wave train logging. The corresponding longitudinal wave velocity and transverse wave velocity are calculated by the longitudinal wave time difference and transverse wave time difference, respectively. Based on the longitudinal wave velocity and transverse wave velocity, the longitudinal wave impedance and transverse wave impedance are calculated by formulas (1) and (2), respectively. Based on the longitudinal wave impedance and transverse wave impedance, the composite wave impedance is calculated by formula (3).

[0118] The fitting module establishes a fitting formula for the composite wave impedance and gas saturation based on the gas saturation and composite wave impedance corresponding to each sample depth. In one example, the fitting formula for the composite wave impedance and gas saturation is as follows:

[0119] S g =1-a*CI-b (4)

[0120] Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

[0121] Specifically, based on the gas saturation and composite wave impedance corresponding to each sample depth, a fitting formula for composite wave impedance and gas saturation is established as formula (4).

[0122] The gas saturation calculation module calculates the composite wave impedance at the target location, and then calculates the gas saturation corresponding to the target location through a fitting formula.

[0123] The present invention also provides an electronic device, comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the above-described method for calculating gas saturation.

[0124] The present invention also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for calculating gas saturation.

[0125] 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 these examples are merely for the purpose of understanding the present invention, and any specific details therein are not intended to limit the present invention in any way.

[0126] Example 1

[0127] Figure 1 A flowchart illustrating the steps of a method for calculating gas saturation according to an embodiment of the present invention is shown.

[0128] like Figure 1 As shown, the gas saturation calculation method includes: Step 101, determining multiple sample depths and their corresponding gas saturations; Step 102, calculating the composite wave impedance corresponding to each sample depth; Step 103, establishing a fitting formula for the composite wave impedance and gas saturation based on the gas saturation and composite wave impedance corresponding to each sample depth; Step 104, calculating the composite wave impedance at the target location, and then calculating the gas saturation corresponding to the target location using the fitting formula.

[0129] Taking the continental shale strata in a certain region as the research object, and based on the composite wave impedance of well logging and the gas saturation of core analysis, a high-precision saturation calculation model suitable for the study area was obtained, which achieved ideal results in the study area, as shown in Table 1.

[0130] Table 1

[0131]

[0132]

[0133]

[0134] Obtain gas saturation from laboratory core analysis. This provides first-hand data for establishing a gas saturation model (Dep). i S gi ), Dep is the sample depth, S gThe value represents the gas saturation, where i = 1, 2, ..., N, and N is the number of samples analyzed for gas saturation. As shown in Table 1, column 1 represents the core number, and column 2, DEP(m), represents the core sampling depth.

[0135] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depth.

[0136] In Table 1, column 3 (AC) represents the P-wave transit time in μs / ft, which will be converted to μs / m. Column 4 (DTS) also represents the P-wave transit time in μs / ft, which will be converted to μs / m. Column 5 represents the bulk density (DEN) in g / cm³. 3 ), Column 6 shows the water saturation of the core sample.

[0137] Calculate the composite wave impedance at each depth.

[0138] If AC is in μs / m, then the P-wave velocity is v. p =1000 / AC, if AC is in μs / ft, then the P-wave velocity is v p =1000 / (AC / 0.3048).

[0139] If DTS is μs / m, then the shear wave velocity is v s =1000 / DTS, if DTS is μs / ft, then the shear wave velocity is v s =1000 / (DTS / 0.3048).

[0140] Then, the longitudinal wave impedance and transverse wave impedance are calculated using formulas (1) and (2), and the composite wave impedance is calculated using formula (3).

[0141] A quantitative calculation model for gas (water) saturation and composite wave impedance was established.

[0142] Figure 2 The diagram shows the results of water saturation calculation from well logging of well Y2 according to an embodiment of the present invention. The first channel is the lithology channel, which includes the caliber curve, natural gamma curve, and uranium-removed natural gamma curve. The second channel is the depth channel. The third channel includes the deep resistivity curve and the shallow resistivity curve. The fourth channel is the porosity logging curve, which includes the P-wave transit time, S-wave transit time, and bulk density curve. The fifth channel is a comparison between the calculated formation water saturation and the water saturation from the core analysis.

[0143] Column 7 of Table 1 shows the calculation of S. w Column 8 represents the absolute error, and column 9 represents the relative error (%).

[0144] In this example, the average absolute error of water saturation is 0.0318, and the average relative error of water saturation is 6.1307%.

[0145] Figure 3 A comparison diagram of gas saturation from well logging calculations and core analysis of well Y2 according to an embodiment of the present invention is shown.

[0146] Using the calculated composite wave impedance CI i Gas saturation S obtained from core analysis gi Using a robust regression method, a model is established as follows: Figure 3 The gas saturation calculation model for continental shale reservoirs shown is as follows:

[0147] S g =1 - 1.1760 * CI - 0.0092

[0148] The correlation coefficient is R = 0.9775.

[0149] Column 10 of Table 1 shows the gas saturation, and column 11 shows the calculated S. g Column 12 shows the absolute error, and column 13 shows the relative error (%).

[0150] In this example, the average absolute error of gas saturation is 0.0299, and the average relative error is 7.3069%.

[0151] Example 2

[0152] Figure 4 A block diagram of a gas saturation calculation device according to an embodiment of the present invention is shown.

[0153] like Figure 4 As shown, the gas saturation calculation device includes:

[0154] Data preparation module 201 determines the depth of multiple samples and their corresponding gas saturation.

[0155] The composite wave impedance calculation module 202 calculates the composite wave impedance corresponding to each sample depth.

[0156] The fitting module 203 establishes a fitting formula for the composite wave impedance and gas saturation based on the gas saturation and composite wave impedance corresponding to each sample depth.

[0157] The gas saturation calculation module 204 calculates the composite wave impedance at the target location, and then calculates the gas saturation corresponding to the target location through a fitting formula.

[0158] As an optional approach, the calculation of the composite wave impedance corresponding to each sample depth includes:

[0159] Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging.

[0160] The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively.

[0161] Calculate the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity.

[0162] As an optional approach, the composite wave impedance is calculated based on the longitudinal wave velocity and the transverse wave velocity, including:

[0163] Calculate the longitudinal wave impedance and transverse wave impedance based on the longitudinal wave velocity and transverse wave velocity, respectively.

[0164] Calculate the composite wave impedance based on the longitudinal wave impedance and the transverse wave impedance.

[0165] As an alternative, the longitudinal wave impedance can be calculated using formula (1):

[0166] AI = C1 * v p *DEN (1)

[0167] Where AI is the longitudinal wave impedance, v p Where is the longitudinal wave velocity, C1 is the calculation coefficient, and DEN is the volume density.

[0168] As an alternative, the transverse wave impedance can be calculated using formula (2):

[0169] SI = C2 * v s *DEN (2)

[0170] Where SI is the transverse wave impedance, v s C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

[0171] As an alternative, the composite wave impedance can be calculated using formula (3):

[0172] CI = v p *(AI+SI) / 2 (3)

[0173] Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p This represents the longitudinal wave velocity.

[0174] As an alternative, the fitting formula for the composite wave impedance and gas saturation is as follows:

[0175] S g =1-a*CI-b (4)

[0176] Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

[0177] Example 3

[0178] This disclosure provides an electronic device comprising: a memory storing executable instructions; and a processor executing the executable instructions in the memory to implement the above-described gas saturation calculation method.

[0179] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0180] This memory is used to store non-transitory 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. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0181] The processor may be a central processing unit (CPU) or other form of processing unit with 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 this disclosure, the processor is used to execute computer-readable instructions stored in the memory.

[0182] Those skilled in the art will understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this disclosure.

[0183] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0184] Example 4

[0185] This disclosure provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the gas saturation calculation method.

[0186] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present disclosure are performed.

[0187] The aforementioned 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 portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0188] Those skilled in the art should understand that the above description of the embodiments of the present invention is only intended to 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 of the examples given.

[0189] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for calculating gas saturation, characterized in that, include: Determine the depth of multiple samples and their corresponding gas saturation; Calculate the composite wave impedance corresponding to each sample depth; Based on the gas saturation and composite wave impedance corresponding to each sample depth, a fitting formula for composite wave impedance and gas saturation is established. Calculate the composite wave impedance at the target location, and then calculate the gas saturation corresponding to the target location using the fitting formula; The composite wave impedance is calculated using formula (3): CI= v p (AI + SI) / 2 (3) where CI is the complex wave impedance, AI is the longitudinal wave impedance, SI is the shear wave impedance, v p is the longitudinal wave velocity.

2. The method for calculating gas saturation according to claim 1, wherein, The calculation of the composite wave impedance corresponding to each sample depth includes: Extract the P-wave transit time, S-wave transit time, and volumetric density of conventional logging at the corresponding depths of sonic wave train logging. The corresponding P-wave velocity and S-wave velocity are calculated using the P-wave time difference and S-wave time difference, respectively. The composite wave impedance is calculated based on the longitudinal wave velocity and the transverse wave velocity.

3. The method for calculating gas saturation according to claim 2, wherein, The calculation of the composite wave impedance based on the longitudinal wave velocity and the transverse wave velocity includes: Calculate the longitudinal wave impedance and the transverse wave impedance based on the longitudinal wave velocity and the transverse wave velocity, respectively. The composite wave impedance is calculated based on the longitudinal wave impedance and the transverse wave impedance.

4. The method for calculating gas saturation according to claim 3, wherein, The longitudinal wave impedance is calculated using formula (1): AI =C1 v p DEN (1) where AI is the longitudinal wave impedance, v p is the longitudinal wave velocity, C1 is a calculation coefficient, and DEN is the bulk density.

5. The method for calculating gas saturation according to claim 3, wherein, The transverse wave impedance is calculated using formula (2): SI =C2 v s DEN (2) Where SI is the transverse wave impedance, v s C1 represents the transverse wave velocity, C2 is the calculation coefficient, and DEN is the bulk density.

6. The method for calculating gas saturation according to claim 1, wherein, The fitting formula for the composite wave impedance and gas saturation is as follows: S g =1-a CI-b (4) Among them, S g denoted as gas saturation, CI as composite wave impedance, and a and b as calculation parameters.

7. A gas saturation calculation device, characterized in that, include: The data preparation module determines the depth of multiple samples and their corresponding gas saturation. The composite wave impedance calculation module calculates the composite wave impedance corresponding to each sample depth. The fitting module establishes a fitting formula for the composite wave impedance and the gas saturation based on the gas saturation and the composite wave impedance corresponding to each sample depth. The gas saturation calculation module calculates the composite wave impedance at the target location, and then calculates the gas saturation corresponding to the target location using the fitting formula. The composite wave impedance is calculated using formula (3): CI= v p (AI + SI) / 2 (3) Where CI is the composite wave impedance, AI is the longitudinal wave impedance, SI is the transverse wave impedance, and v p This represents the longitudinal wave velocity.

8. An electronic device, characterized in that, The electronic device includes: Memory, which stores executable instructions; A processor that executes the executable instructions in the memory to implement the gas saturation calculation method according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the gas saturation calculation method according to any one of claims 1-6.

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