Method and system for evaluating movable water saturation of tight sandstone gas reservoir

Abstract

The invention discloses a method and system for evaluating the movable water saturation of a tight sandstone gas reservoir, and the method comprises the steps: completing the evaluation of the movable water saturation of the tight sandstone gas reservoir through the electrical resistivity, the interval transit time, the permeability and the water saturation in combination with a movable water saturation model; according to the evaluation method, mercury injection experiment data is not needed, conventional logging data are utilized, and the method has good universality. According to the method, under the condition that logging series are not increased, movable water saturation interpretation is achieved, operation is easy, and the application range is wide.

Description

Technical Field

[0001] The invention belongs to the technical field of natural gas development, and relates to a method and system for evaluating movable water saturation of a tight sandstone gas reservoir. Background Art

[0002] For tight sandstone gas reservoirs, movable water saturation is the critical parameter for gas phase and gas-water two-phase seepage. It is also an important parameter for evaluating oil and gas reservoirs, predicting production capacity and formulating development plans. Therefore, it is of great significance to study the movable water saturation of tight sandstone gas reservoirs.

[0003] Chinese patent 201910221661.X discloses a method for calculating the well logging saturation of sandstone oil and gas layers, and explains that the main reason for the formation of low resistivity of oil (gas) layers is the equivalent additional conductivity caused by the conductive network formed by a small amount of movable water or bound water distributed in effective pores or movable pores and the water on the inner wall of the pore throat of hydrophilic rocks, as well as the conductivity of the bound water itself. After revision, the calculation model or method is applicable to the saturation calculation of conventional resistivity oil (gas) layers and low-resistivity oil (gas) layers, and significantly improves the calculation results of hydrocarbon saturation of low-resistivity oil (gas) layers. It is applicable to the situation where the saturation calculation results of oil (gas) layers are low, improves the calculation results of oil (gas) saturation, and becomes the standard of the resistivity calculation saturation model of sandstone oil (gas) layers.

[0004] Chinese patent 201710890856.4 discloses a method for quantitatively evaluating movable water saturation of sandstone reservoirs by array induction and lateral logging. The Archie formula is used as the water saturation calculation model, and the water saturation of the reservoir is calculated by using lateral deep resistivity and induction deep resistivity respectively; the water saturation calculated by induction deep resistivity is corrected for bound water saturation; the difference between the induction water saturation corrected by mud bound water saturation and the water saturation calculated by lateral deep resistivity is the increment D; the ratio of increment D to the gas saturation calculated by lateral deep resistivity can be used to quantitatively evaluate movable water saturation. This method realizes a method for quantitatively evaluating movable water saturation of reservoirs based on array induction deep resistivity and lateral logging deep resistivity of conventional logging data, which can quickly and accurately realize continuous quantitative evaluation of movable water saturation of reservoirs and can reliably identify reservoir fluids.

[0005] Chinese patent 201910221661.X uses the equivalent additional conductivity caused by the conductive network formed by the water on the inner wall of the rock pore throat to significantly improve the calculation results of the hydrocarbon saturation of the low-resistivity oil (gas) layer. However, this result can only explain the oil (gas) saturation and water saturation, and cannot explain the movable water saturation and bound water saturation in the water saturation. Chinese patent 201710890856.4 uses the ratio of the difference between the water saturation calculated by induction water saturation and lateral deep resistivity to the gas saturation calculated by lateral deep resistivity to quantitatively evaluate the movable water saturation, and can realize the interpretation of movable water saturation. This method is suitable for oil and gas wells that have both deep and shallow lateral resistivity logging and array induction logging. Array induction, as a special logging, is not implemented in the conventional exploration well and development well logging series of general oil and gas fields, so it has limitations. Summary of the invention

[0006] In view of the problems existing in the prior art, the present invention provides a method and system for evaluating movable water saturation of tight sandstone gas reservoirs, thereby solving the technical problem that the prior art cannot determine the movable water saturation in conventional exploration wells, development wells and well logging.

[0007] The present invention is achieved through the following technical solutions:

[0008] A method for evaluating movable water saturation of a tight sandstone gas reservoir comprises the following steps:

[0009] The movable water saturation of the tight sandstone gas reservoir is evaluated by using resistivity, acoustic wave time difference, permeability and water saturation in combination with a movable water saturation model;

[0010] The movable water saturation model is

[0011] S MW =S i -S W

[0012] S W =a*RT+b*AC+c*K+d

[0013] In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is the resistivity, AC is the acoustic time difference, K is the permeability; a, b, c and d are constants.

[0014] Preferably, the irreducible water saturation model is established as follows:

[0015] S201: obtaining the maximum capillary radius, the minimum capillary radius, the critical capillary radius, the capillary radius, the displacement pressure difference and the water phase viscosity of several groups of well logging;

[0016] S202: obtaining several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging according to the several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius;

[0017] S203: using the plurality of groups of the maximum capillary radius, the minimum capillary radius, the critical capillary radius, the capillary radius, the displacement pressure difference, the water phase viscosity, the tortuosity fractal dimension and the pore fractal dimension, in combination with an irreducible water saturation model established according to fractal theory, to obtain a plurality of groups of irreducible water saturations;

[0018] S204: Establishing the irreducible water saturation model according to the plurality of groups of irreducible water saturations and logging parameters.

[0019] Preferably, the irreducible water saturation model established based on fractal theory is:

[0020]

[0021] Where: S′ w is the bound water saturation established based on fractal theory, %; r max is the maximum capillary radius, μm; r min is the minimum capillary radius, μm; r c is the critical capillary radius, μm; r is the capillary radius, μm; D τ is the fractal dimension of tortuosity; D p is the pore fractal dimension; Δp is the displacement pressure difference, MPa; μ w is the viscosity of the water phase, MPa·s; A, m and n are constants.

[0022] Preferably, the maximum capillary radius, the minimum capillary radius, the critical capillary radius and the capillary radius are obtained through a mercury injection experiment.

[0023] Preferably, according to fractal theory, several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging are obtained through several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius.

[0024] Preferably, the logging parameters include lithology, physical properties and gas content.

[0025] The above-mentioned method for evaluating movable water saturation of tight sandstone gas reservoirs is applied in establishing a reservoir classification identification chart.

[0026] A system for evaluating movable water saturation of tight sandstone gas reservoirs, comprising:

[0027] Data processing module: The data processing module is used to evaluate the movable water saturation of the tight sandstone gas reservoir by using resistivity, acoustic wave time difference, permeability and water saturation, combined with the movable water saturation model. The movable water saturation model is

[0028] S MW =S i -S W

[0029] S W =a*RT+b*aC+c*K+d

[0030] In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is the resistivity, AC is the acoustic time difference, K is the permeability; a, b, c and d are constants.

[0031] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0032] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0033] Compared with the prior art, the present invention has the following beneficial technical effects:

[0034] Based on the above technical scheme, the movable water saturation evaluation method of a tight sandstone gas reservoir disclosed in the present invention uses a movable water saturation model established by combining conventional logging parameters such as resistivity, acoustic wave time difference, permeability, and water saturation, which can effectively realize the evaluation of movable water saturation of conventional wells. The evaluation method does not require mercury injection experimental data, but can use conventional logging data, and has good universality. The method realizes the interpretation of movable water saturation without increasing the logging series, is simple to operate, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 This is a schematic flow chart of a method for evaluating movable water saturation of a tight sandstone gas reservoir in Example 1 of the present invention;

[0037] Figure 2 This is a schematic structural diagram of a system for evaluating movable water saturation of a tight sandstone gas reservoir in Example 3 of the present invention;

[0038] Figure 3 is the movable water saturation S established in Example 5 of the present invention MW Explanatory diagram;

[0039] Figure 4 This is a cross-plot of KH and movable water saturation in the application of the movable water saturation obtained in Example 5 of the present invention in establishing a reservoir classification identification chart. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0043] In the description of the embodiments of the present invention, it should be noted that if the terms "upper", "lower", "horizontal", "inner", etc. indicate an orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use, it is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0044] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", which does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0045] In the description of the embodiments of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0047] Example 1

[0048] like Figure 1 As shown, the present invention discloses a method for evaluating movable water saturation of a tight sandstone gas reservoir, comprising the following steps:

[0049] S1: using the resistivity, acoustic wave time difference, permeability and water saturation, and combining with a movable water saturation model, completing the evaluation of the movable water saturation of the tight sandstone gas reservoir;

[0050] The movable water saturation model is

[0051] S MW =S i -S W

[0052] S W =a*RT+b*AC+c*K+d

[0053] In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is resistivity, AC is acoustic time difference, K is permeability; a, v, c and d are constants. a, b, c and d are obtained by fitting the specific parameters of a specific gas field or block, and the parameters obtained by regression for different gas fields may be different. a, b, c and d are obtained by fitting the known mercury injection test data and logging test data.

[0054] The establishment of the irreducible water saturation model is as follows:

[0055] S201: obtaining a maximum capillary radius, a minimum capillary radius, a critical capillary radius, a capillary radius, a displacement pressure difference, and a water phase viscosity of several groups of well logging; wherein the maximum capillary radius, the minimum capillary radius, the critical capillary radius, and the capillary radius are obtained through a mercury injection experiment.

[0056] S202: Obtaining several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging according to the several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius; wherein, according to fractal theory, obtaining several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging through several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius.

[0057] S203: using the plurality of groups of the maximum capillary radius, the minimum capillary radius, the critical capillary radius, the capillary radius, the displacement pressure difference, the water phase viscosity, the tortuosity fractal dimension and the pore fractal dimension, in combination with an irreducible water saturation model established according to fractal theory, to obtain a plurality of groups of irreducible water saturations;

[0058] S204: establishing the irreducible water saturation model according to the plurality of groups of irreducible water saturations and logging parameters, wherein the logging parameters include lithology, physical properties, and gas content.

[0059] The irreducible water saturation model established based on fractal theory is:

[0060]

[0061] Where: S′ w is the bound water saturation established based on fractal theory, %; r max is the maximum capillary radius, μm; r min is the minimum capillary radius, μm; r c is the critical capillary radius, μm; r is the capillary radius, μm; D τ is the fractal dimension of tortuosity; D p is the pore fractal dimension; Δp is the displacement pressure difference, MPa; μ w is the water phase viscosity, MPa·s; A, m and n are constants. A, m and n are obtained by fitting the specific parameters of a specific gas field or block, and the parameters obtained by regression for different gas fields may be different. A, m and n are obtained by fitting the known mercury injection test data and irreducible water saturation data.

[0062] Example 2

[0063] In another preferred embodiment of the present invention, a method for evaluating movable water saturation of a tight sandstone gas reservoir may include the following steps:

[0064] S1: Obtain the resistivity, acoustic wave time difference, permeability and water saturation of the well to be tested;

[0065] S2: using the resistivity, acoustic wave time difference, permeability and water saturation, and combining with a movable water saturation model, to complete the evaluation of the movable water saturation of the tight sandstone gas reservoir;

[0066] The movable water saturation model is

[0067] S MW =S i -S W

[0068] S W =a*RT+b*AC+c*K+d

[0069] In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is the resistivity, AC is the acoustic time difference, K is the permeability; a, b, c and d are constants. a, b, c and d are obtained by fitting the known mercury injection test data and logging test data.

[0070] The invention also discloses the application of the movable water saturation evaluation method of the tight sandstone gas reservoir in the present application in establishing a reservoir classification identification chart.

[0071] Example 3

[0072] like Figure 2 As shown, the present invention also discloses a system for evaluating movable water saturation of tight sandstone gas reservoirs, comprising:

[0073] Data processing module: the data processing module is used to evaluate the movable water saturation of the tight sandstone gas reservoir by using the resistivity, acoustic wave time difference, permeability and water saturation in combination with a movable water saturation model;

[0074] The movable water saturation obtained in the present invention is a reservoir property independent of porosity, permeability, gas saturation and effective reservoir thickness, and can be used as one of the reservoir evaluation parameters for tight sandstone gas reservoirs, making the reservoir evaluation of tight sandstone water-bearing gas reservoirs more comprehensive and accurate.

[0075] Example 4

[0076] The movable water saturation evaluation system for tight sandstone gas reservoirs of the present invention may also include the following components:

[0077] Data acquisition module: The data acquisition module is used to obtain the resistivity, acoustic wave time difference, permeability and water saturation of the well to be measured;

[0078] Data processing module: the data processing module is used to evaluate the movable water saturation of the tight sandstone gas reservoir by using the resistivity, acoustic wave time difference, permeability and water saturation in combination with a movable water saturation model;

[0079] Result output module: The result output module is used to output the movable water saturation of tight sandstone gas reservoirs.

[0080] Example 5

[0081] To further explain the technical solution of the present invention, the following embodiments are used for explanation:

[0082] A method for interpreting movable water saturation of a tight sandstone gas reservoir comprises the following steps:

[0083] (1) Obtain the irreducible water saturation formula for tight sandstone gas reservoirs. Tight sandstone is a porous medium with fractal pore structure. The irreducible water saturation formula is obtained using fractal theory.

[0084] The formula for bound water saturation obtained by the fractal theory is as follows:

[0085]

[0086] Where: S′ w is the bound water saturation established based on fractal theory, %; r max is the maximum capillary radius, μm; r min is the minimum capillary radius, μm; r c is the critical capillary radius, μm; r is the capillary radius, μm; D τ is the fractal dimension of tortuosity; D p is the pore fractal dimension; Δp is the displacement pressure difference, MPa; μ w is the viscosity of the water phase, MPa·s.

[0087] (2) Obtaining irreducible water saturation of cores. According to a method for predicting irreducible water saturation of tight sandstone reservoirs based on fractal theory, irreducible water saturation is calculated using a large amount of mercury injection experimental data;

[0088] (3) Establishing a relationship between the calculated irreducible water saturation and logging parameters. The calculated irreducible water saturation is fitted with different logging parameters (lithology, physical properties, gas content and other logging parameters related to water saturation), multiple regression formulas are established, and the optimal regression formula is selected as the irreducible water saturation interpretation formula; the irreducible water saturation fitting regression formula established is shown in Table 1, and the irreducible water saturation interpretation formula with the highest correlation coefficient is selected, that is, the preferred formula 11.

[0089] Table 1. Regression formula for bound water saturation

[0090]

[0091] In the formula, S Wis the bound water saturation model, RT is the resistivity, Ω·m, AC is the acoustic time difference, μs / m, K is the permeability, mD, GR is the natural gamma, API, is the porosity, %, SH is the shale content, %, DEN is the density, g / cm 3 .

[0092] (4) Obtain the movable water saturation interpretation formula. Combine the original water saturation interpretation formula of the well logging, subtract the calculated bound water saturation, and obtain the movable water saturation, and obtain the movable water saturation interpretation formula;

[0093] S MW =S i -S W

[0094] S W =-0.0793*RT+0.3159*AC-12.4143*K-35.21

[0095] The movable water saturation is used for gas well logging interpretation. The movable water saturation S MW Explanation Figure 3 As shown, the reservoir evaluation of tight sandstone water-bearing gas reservoirs is more comprehensive and accurate.

[0096] At the same time, in one application of the present invention, the formation coefficient (KH-permeability × gas layer thickness) can be introduced and associated with the movable water saturation to obtain a reservoir classification identification chart for reservoir classification evaluation. Figure 4 ,Depend on Figure 4 It can be seen that the classification of gas wells according to movable water saturation and formation coefficient takes into account both the static geological characteristics of gas wells and the impact of gas well water production on gas well production capacity. After the introduction of movable water saturation, the dynamic and static conformity rate of gas wells increased by 24.3%, which is of great significance for the fine classification and management of gas wells; at the same time, the use of reservoir classification identification charts can effectively guide perforation optimization and old well layer inspection and perforation supplementation, with significant results.

[0097] A schematic diagram of a terminal device provided in an embodiment of the present invention. The terminal device of this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0098] The computer program may be divided into one or more modules / units, and the one or more modules / units are stored in the memory and executed by the processor to accomplish the present invention.

[0099] The terminal device may be a computing device such as a desktop computer, a notebook, a palmtop computer, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0100] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0101] The memory may be used to store the computer program and / or module, and the processor implements various functions of the terminal device by running or executing the computer program and / or module stored in the memory and calling the data stored in the memory.

[0102] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0103] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating movable water saturation of tight sandstone gas reservoirs, characterized in that: The following steps are involved: The movable water saturation of the tight sandstone gas reservoir is evaluated by using resistivity, acoustic wave time difference, permeability and water saturation in combination with a movable water saturation model; The movable water saturation model is S MW =S i -S W S W =a*RT+b*AC+c*K+d In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is the resistivity, AC is the acoustic time difference, K is the permeability; a, b, c and d are constants.

2. The method for evaluating movable water saturation of a tight sandstone gas reservoir according to claim 1, characterized in that: The establishment of the irreducible water saturation model is specifically as follows: S201: obtaining the maximum capillary radius, the minimum capillary radius, the critical capillary radius, the capillary radius, the displacement pressure difference and the water phase viscosity of several groups of well logging; S202: obtaining several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging according to the several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius; S203: using the plurality of groups of the maximum capillary radius, the minimum capillary radius, the critical capillary radius, the capillary radius, the displacement pressure difference, the water phase viscosity, the tortuosity fractal dimension and the pore fractal dimension, in combination with an irreducible water saturation model established according to fractal theory, to obtain a plurality of groups of irreducible water saturations; S204: Establishing the irreducible water saturation model according to the plurality of groups of irreducible water saturations and logging parameters.

3. A method for evaluating movable water saturation of tight sandstone gas reservoirs according to claim 2, characterized in that: The irreducible water saturation model established based on fractal theory is: Where: S′ w is the bound water saturation established based on fractal theory, %; r max is the maximum capillary radius, μm; r min is the minimum capillary radius, μm; r c is the critical capillary radius, μm; r is the capillary radius, μm; D τ is the fractal dimension of tortuosity; D p is the pore fractal dimension; Δp is the displacement pressure difference, MPa; μ w is the viscosity of the water phase, MPa·s; A, m and n are constants.

4. A method for evaluating movable water saturation of tight sandstone gas reservoirs according to claim 2, characterized in that: The maximum capillary radius, the minimum capillary radius, the critical capillary radius and the capillary radius are obtained through mercury injection experiments.

5. The method for evaluating movable water saturation of tight sandstone gas reservoirs according to claim 2, characterized in that: According to fractal theory, several groups of tortuosity fractal dimensions and pore fractal dimensions of the well logging are obtained through several groups of maximum capillary radius, minimum capillary radius, critical capillary radius and capillary radius.

6. A method for evaluating movable water saturation of tight sandstone gas reservoirs according to claim 2, characterized in that: The logging parameters include lithology, physical properties and gas content.

7. Application of the method for evaluating movable water saturation of tight sandstone gas reservoirs as claimed in any one of claims 1 to 6 in establishing a reservoir classification identification chart.

8. A system for evaluating movable water saturation of tight sandstone gas reservoirs, characterized in that: include: Data processing module: The data processing module is used to evaluate the movable water saturation of the tight sandstone gas reservoir by using resistivity, acoustic wave time difference, permeability and water saturation, combined with the movable water saturation model. The movable water saturation model is S MW =S i -S W S W =a*RT+b*AC+c*K+d In the formula, S MW is the movable water saturation, S i is water saturation, S W is the irreducible water saturation model, RT is the resistivity, AC is the acoustic time difference, K is the permeability; a, b, c and d are constants.

9. A terminal device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

Images