Method, device, electronic device and storage medium for measuring relative wettability of air and water

Abstract

The present invention provides a method, device, electronic device and storage medium for measuring relative wettability of gas and water. The method comprises: obtaining a rock sample, vacuumizing and saturating the rock sample with water, and obtaining a first nuclear magnetic resonance T corresponding to the rock sample in a saturated water state. 2 Spectral signal; gas flooding treatment is performed on the rock sample in the water-saturated state, and the second nuclear magnetic resonance T corresponding to the rock sample in the water-flooding state is obtained. 2 Spectral signal; based on the first NMR T 2 Spectral signal and second NMR T 2 The spectral signal quantity is used to determine the water-containing pores and gas-containing pores in the rock sample; the water-containing pore fractal dimension values ​​corresponding to the water-containing pores and the gas-containing pore fractal dimension values ​​corresponding to the gas-containing pores are determined respectively; based on the water-containing pore fractal dimension values ​​and the gas-containing pore fractal dimension values, the gas-water relative wettability characteristics of the rock sample are determined. The present invention can accurately measure the gas-water relative wettability in a tight sandstone gas reservoir.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas exploration, and in particular to a method, a device, an electronic device and a storage medium for measuring relative wettability of gas and water. Background Art

[0002] Wettability refers to the ability of a phase fluid in a mixed fluid to wet the solid surface first, that is, the ability or tendency of a fluid to spread on a solid surface. The wettability of rock will affect the fluid distribution inside the rock, and then affect the oil and gas accumulation in the rock. By measuring the wettability inside the rock, the oil and gas accumulation inside the rock can be effectively determined, which is convenient for subsequent exploration and development.

[0003] In the related technologies, the research on wettability characteristics is mainly oriented to the wettability characteristics of oil-water two-phase fluids, and there is a lack of research on the wettability characteristics of gas-water two-phase fluids. However, for tight sandstone gas reservoirs, which have low porosity, low permeability, and complex pore structures, the measurement method of the wettability of oil-water two-phase fluids is not suitable. Therefore, it is urgent to establish a method for measuring the wettability of gas-water two-phase fluids for tight sandstone gas reservoirs, so as to facilitate the subsequent precise exploration and development of tight sandstone gas reservoirs. Summary of the invention

[0004] The embodiments of the present invention provide a method, device, electronic device and storage medium for measuring the relative wettability of gas and water, so as to accurately measure the relative wettability of gas and water in a tight sandstone gas reservoir, thereby facilitating subsequent accurate exploration and development.

[0005] In a first aspect, an embodiment of the present invention provides a method for measuring relative wettability of air and water, comprising:

[0006] Obtaining a rock sample, performing a vacuum saturated water treatment on the rock sample to obtain a rock sample in a saturated water state, and obtaining a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state;

[0007] Performing gas water flooding treatment on the rock sample in the water-saturated state to obtain a rock sample in the water-flooding state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooding state;

[0008] Determining water-bearing pores and gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount;

[0009] respectively determining the water-containing pore fractal dimension values ​​corresponding to the water-containing pores and the air-containing pore fractal dimension values ​​corresponding to the air-containing pores;

[0010] Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, the gas-water relative wettability characteristics of the rock sample are determined.

[0011] In a possible implementation, determining the water-containing pores and the gas-containing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal includes:

[0012] Determining the pore volume ratio in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal;

[0013] Based on the pore volume percentage, the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount, respectively determine the pore percentage corresponding to different relaxation times of the rock sample in a water-saturated state and the pore percentage corresponding to different relaxation times of the rock sample in a water-flooding state;

[0014] Determine the critical relaxation time based on the pore proportions corresponding to different relaxation times of rock samples in a water-saturated state and a water-flooded state;

[0015] The pores with a relaxation time greater than the critical relaxation time are determined as gas-containing pores in the rock sample, and the pores with a relaxation time less than the critical relaxation time are determined as water-containing pores in the rock sample.

[0016] In a possible implementation, the critical relaxation time is determined based on the pore proportions corresponding to different relaxation times of the rock sample in the water-saturated state and the rock sample in the water-flooding state, including:

[0017] Determine a first curve based on the pore proportions of the rock sample in a water-saturated state corresponding to different relaxation times; the first curve is used to characterize the cumulative pore proportions of the rock sample in a water-saturated state corresponding to different relaxation times;

[0018] Based on the pore proportions of the rock sample under the water flooding state corresponding to different relaxation times, a second curve is determined; the second curve is used to characterize the cumulative pore proportions of the rock sample under the water flooding state corresponding to different relaxation times;

[0019] When the curvature of the second curve is zero, a tangent line corresponding to the second curve is obtained, an intersection point between the tangent line and the first curve is determined, and a relaxation time corresponding to the intersection point is determined as the critical relaxation time.

[0020] In a possible implementation, determining the gas-water relative wettability characteristics of the rock sample based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value includes:

[0021] Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample;

[0022] When the relative affinity for air index is greater than a first preset value, and the relative affinity for water index is less than a second preset value, determining that the rock sample is relatively affinity for air;

[0023] When the relative air affinity index is less than the second preset value, and the relative water affinity index is greater than the first preset value, it is determined that the rock sample is relatively hydrophilic;

[0024] When the relative air affinity index and the relative water affinity index are both greater than or equal to the second preset value and less than or equal to the first preset value, the gas-water affinity of the rock sample is determined.

[0025] In a possible implementation, determining the pore volume ratio in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal includes:

[0026] Performing vacuum degassing and drying treatment on the rock sample, and obtaining a third nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample after the vacuum degassing and drying treatment;

[0027] Determining the volume of water in the rock sample in the water-saturated state based on the difference between the first nuclear magnetic resonance T2 spectrum signal amount and the third nuclear magnetic resonance T2 spectrum signal amount;

[0028] Based on the volume of water in the rock sample in the water-saturated state, the pore volume fraction in the rock sample is determined.

[0029] In a possible implementation, based on the pore volume percentage, the first nuclear magnetic resonance T2 spectrum signal amount, and the second nuclear magnetic resonance T2 spectrum signal amount, the pore percentages corresponding to different relaxation times of the rock sample in a water-saturated state and the pore percentages corresponding to different relaxation times of the rock sample in a water-flooding state are respectively determined;

[0030] Based on the ratio between the pore fraction and the first nuclear magnetic resonance T2 spectrum signal, determining the pore fraction corresponding to different relaxation times of the rock sample in a water-saturated state;

[0031] Based on the ratio between the pore fraction and the signal quantity of the second nuclear magnetic resonance T2 spectrum, the pore fraction corresponding to different relaxation times of the rock sample in the water-flooding state is determined.

[0032] In a possible implementation, based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample includes:

[0033] according to Determining the relative affinity index;

[0034] according to Determining the relative hydropathic index;

[0035] Among them, I xg Denotes the relative affinity index, D g represents the fractal dimension value of the gas-containing pores, D w represents the fractal dimension value of the water-containing pores, I xw It represents the relative hydropathic index.

[0036] In a second aspect, an embodiment of the present invention provides a device for measuring relative wettability of air and water, comprising:

[0037] Measurement modules for:

[0038] Obtaining a rock sample, performing a vacuum saturated water treatment on the rock sample to obtain a rock sample in a saturated water state, and obtaining a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state;

[0039] Performing gas water flooding treatment on the rock sample in the water-saturated state to obtain a rock sample in the water-flooding state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooding state;

[0040] Compute module for:

[0041] Determining water-bearing pores and gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount;

[0042] respectively determining the water-containing pore fractal dimension values ​​corresponding to the water-containing pores and the air-containing pore fractal dimension values ​​corresponding to the air-containing pores;

[0043] Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, the gas-water relative wettability characteristics of the rock sample are determined.

[0044] In a third aspect, an embodiment of the present invention provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the processor implements the steps of the method described in the first aspect or any possible implementation manner of the first aspect.

[0045] In a fourth aspect, an embodiment of the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in the first aspect or any possible implementation method of the first aspect are implemented.

[0046] The embodiment of the present invention provides a method, device, electronic device and storage medium for measuring relative wettability of gas and water. Based on a first nuclear magnetic resonance T2 spectrum signal corresponding to a rock sample in a water-saturated state and a second nuclear magnetic resonance T2 spectrum signal corresponding to a rock sample in a water-displaced state, water-containing pores and gas-containing pores in the rock sample are determined, and then the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores are determined to obtain the relative wettability characteristics of gas and water in the rock sample. In particular, the embodiment of the present invention can divide the gas-water two-phase fluid storage space through the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal, thereby dividing the pores in the rock sample into water-containing pores and gas-containing pores. On this basis, the wettability characteristics of the pores inside the rock sample can be characterized through the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, and then the relative wettability characteristics of gas and water in the rock sample are determined, and finally the relative wettability characteristics of gas and water in the rock sample are accurately measured, so as to facilitate the subsequent accurate exploration and development of tight sandstone gas reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0048] Figure 1 is a flow chart of the method for measuring relative wettability of air and water provided in an embodiment of the present invention;

[0049] Figure 2 is a flowchart for determining water-containing pores and gas-containing pores in a rock sample provided by an embodiment of the present invention;

[0050] Figure 3 is a schematic diagram of a first curve corresponding to a saturated water state and a second curve corresponding to a water-displacement state provided by an embodiment of the present invention;

[0051] Figure 4 is lg(i)-lg(E zi )Point-line graph;

[0052] Figure 5 is a schematic diagram of a fitting curve between a contact angle and a relative hydrophilicity index provided by an embodiment of the present invention;

[0053] Figure 6 is a schematic diagram of a fitting curve between the contact angle and the relative air affinity index provided in an embodiment of the present invention;

[0054] Figure 7is a schematic structural diagram of a device for measuring relative wettability of air and water provided in an embodiment of the present invention;

[0055] Figure 8 is a schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present invention. However, it should be clear to those skilled in the art that the present invention may be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present invention.

[0057] In the related technologies, the measurement of rock internal wettability is mainly for the measurement of oil-water two-phase fluid wettability, and lacks the measurement of gas-water two-phase wettability. However, for tight sandstone gas reservoirs with low porosity, low permeability and complex pore structure, the measurement method of oil-water two-phase fluid wettability is not suitable. Therefore, it is urgent to establish a gas-water two-phase wettability measurement method for tight sandstone gas reservoirs, so as to facilitate the subsequent precise exploration and development of tight sandstone gas reservoirs.

[0058] In order to accurately measure the relative wettability of gas and water in tight sandstone gas reservoirs, so as to facilitate the subsequent accurate exploration and development of tight sandstone gas reservoirs, in the implementation of the present application, based on the first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in a water-saturated state, and the second nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in a water-displaced state, the water-containing pores and gas-containing pores in the rock sample are determined, and by determining the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, the gas-water relative wettability characteristics in the rock sample are obtained, wherein, Through the first nuclear magnetic resonance T2 spectrum signal quantity and the second nuclear magnetic resonance T2 spectrum signal quantity, the gas-water two-phase fluid storage space can be divided, so that the pores in the rock sample can be divided into water-containing pores and gas-containing pores. On this basis, the wettability characteristics of the pores inside the rock sample can be characterized by the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, and then the gas-water relative wettability characteristics of the rock sample can be determined, and finally the gas-water relative wettability characteristics of the rock sample can be accurately measured, so as to facilitate the subsequent accurate exploration and development of tight sandstone gas reservoirs.

[0059] In order to make the purpose, technical solutions and advantages of the present invention more clear, specific embodiments will be described below in conjunction with the accompanying drawings.

[0060] Figure 1 The implementation flow chart of the method for measuring relative wettability of air and water provided in the embodiment of the present invention is described in detail as follows:

[0061] Step 101, obtain a rock sample, perform a vacuum saturated water treatment on the rock sample to obtain a rock sample in a saturated water state, and obtain a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state.

[0062] Before measuring the relative wettability of gas and water, the embodiment of the present invention first collects and prepares a rock sample of the tight sandstone gas reservoir to be measured. Here, the tight sandstone gas reservoir to be measured can be cut by water cutting or metal wire cutting to obtain a rock sample of a preset size.

[0063] The preset size here can be determined according to actual conditions. For example, the rock sample can be a cylinder with a length of 3 to 5 cm and a diameter of 2 to 3 cm.

[0064] In the embodiment of the present invention, before vacuuming and saturating the rock sample with water, the rock sample may be vacuum degassed and dried to remove moisture, air and other impurity gases in the rock sample. Here, the vacuum degassing drying temperature and the vacuum degassing drying time may be determined according to actual conditions. For example, the vacuum degassing drying temperature may be 110° C., and the vacuum degassing drying time may be 24 hours.

[0065] The embodiment of the present invention performs vacuum treatment on the rock sample after vacuum degassing and drying, and pressurizes saturated water to obtain the rock sample in a saturated water state, and then obtains the first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state.

[0066] Here, the water sample used in the pressurized saturated water may be pure water, or a water sample configured according to the actual formation water conditions of the tight sandstone gas reservoir to be measured.

[0067] It should be noted that the experimental environment in which the rock sample is placed when pressurized and saturated with water is the same as the experimental environment in which the first nuclear magnetic resonance T2 spectrum signal is obtained, that is, the preset pressure and the preset temperature. The preset pressure and the preset temperature here need to be determined according to the actual situation.

[0068] Step 102, performing gas water flooding treatment on the rock sample in a water-saturated state to obtain a rock sample in a water-flooded state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooded state.

[0069] Considering that natural gas is mainly stored in tight sandstone gas reservoirs, methane or mixed hydrocarbon gas may be used for water displacing when performing gas water displacing treatment in the embodiments of the present invention.

[0070] When performing water-flooding treatment on rock samples in a water-saturated state, methane or mixed hydrocarbon gas is first used to flood the rock samples in a water-saturated state to obtain rock samples after water-flooding, and then the rock samples after water-flooding are subjected to vacuum degassing treatment at normal temperature and pressure to remove methane or mixed hydrocarbon gas in the rock samples, and finally obtain rock samples in a water-flooded state.

[0071] Accordingly, the experimental environment in which the rock sample is located when methane or mixed hydrocarbon gas is used for water displacement and the experimental environment in which the rock sample is located when the second nuclear magnetic resonance T2 spectrum signal is obtained are the same as the experimental environment in which the first nuclear magnetic resonance T2 spectrum signal is obtained, that is, the preset pressure and preset temperature.

[0072] Step 103: determining water-bearing pores and gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal quantity and the second nuclear magnetic resonance T2 spectrum signal quantity.

[0073] Low-field nuclear magnetic resonance technology has the advantages of being fast, accurate, non-destructive and harmless, and having high resolution. When the hydrogen nuclei relax in the pores, they will collide with the pore walls, causing energy loss and returning from a high-energy state to a low-energy state.

[0074] Based on this, the embodiment of the present invention obtains the first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the water-saturated state and the second nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the water-displaced state. Based on the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal, the distribution characteristics of different hydrogen-containing fluids in the pores inside the rock sample can be detected, and the gas-water two-phase fluid storage space can be divided accordingly, so that the pores in the rock sample can be divided into water-containing pores and gas-containing pores.

[0075] Step 104, respectively determining water-containing pore fractal dimension values ​​corresponding to the water-containing pores and gas-containing pore fractal dimension values ​​corresponding to the gas-containing pores.

[0076] The single fractal theory can be used to characterize the heterogeneity characteristics of rock pore structure. By calculating the single fractal dimension value, the complexity of the pore structure and the roughness of the pore surface of the rock sample can be quantitatively characterized. The larger the single fractal dimension value, the more complex the pore structure, the rougher the pore surface, and the stronger the pore heterogeneity characteristics. The heterogeneity characteristics of different types of pores containing different types of fluids are obviously different. Therefore, the embodiments of the present invention respectively determine the fractal dimension values ​​of water-containing pores and gas-containing pores, which are used to characterize the wettability characteristics of different types of pores.

[0077] Step 105, determining the gas-water relative wettability characteristics of the rock sample based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value.

[0078] The above water-containing pore fractal dimension values ​​and gas-containing pore fractal dimension values ​​are used to characterize the wettability characteristics of water-containing pores and gas-containing pores in rock samples, respectively. Based on the wettability characteristics of water-containing pores and gas-containing pores, the gas-water relative wettability characteristics of rock samples can be further determined.

[0079] Here, the relative wettability characteristics of gas and water can include: relatively gas-friendly, relatively water-friendly, and gas-water-ambivalent. Among them, the more relatively gas-friendly the reservoir is, the easier it is to store tight sandstone gas, and the more relatively water-friendly the reservoir is, the easier it is to store a large amount of water during the tight sandstone gas accumulation process, which is not conducive to the tight sandstone gas accumulation.

[0080] After determining the gas-water relative wettability characteristics of the rock sample, the embodiment of the present invention can determine whether to explore and exploit the tight sandstone gas reservoir where the rock sample is located according to the gas-water relative wettability of the rock sample. If the gas-water relative wettability characteristics of the rock sample are relatively gas-friendly, the tight sandstone gas reservoir where the rock sample is located is explored and exploited. If the gas-water relative wettability characteristics of the rock sample are relatively hydrophilic or gas-water amphiphilic, the tight sandstone gas reservoir where the rock sample is located is not explored and exploited.

[0081] Compared with the prior art, the embodiment of the present invention determines the water-containing pores and gas-containing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the water-saturated state and the second nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the water-displaced state, and obtains the relative wettability characteristics of gas and water in the rock sample by determining the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, wherein the distribution characteristics of different hydrogen-containing fluids in the pores inside the rock sample are detected by the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal, and the gas-water two-phase fluid storage space is divided thereby, so that the pores in the rock sample are divided into water-containing pores and gas-containing pores. On this basis, the wettability characteristics of different types of pores inside the rock sample can be characterized by the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, and the relative wettability characteristics of gas and water in the rock sample are determined, and finally the relative wettability characteristics of gas and water in the rock sample are accurately measured, so as to facilitate the subsequent precise exploration and development of tight sandstone gas reservoirs.

[0082] In some embodiments, see Figure 2 When determining water-bearing pores and gas-bearing pores in a rock sample based on the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal, the following steps can be performed:

[0083] Step 201, determining the pore volume ratio in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal.

[0084] In some embodiments, when determining the pore volume percentage in a rock sample, the rock sample can be first subjected to a vacuum degassing and drying treatment, and a third nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample after the vacuum degassing and drying treatment can be obtained; then, based on the difference between the first nuclear magnetic resonance T2 spectrum signal and the third nuclear magnetic resonance T2 spectrum signal, the volume of water in the rock sample in a water-saturated state is determined; finally, based on the volume of water in the rock sample in a water-saturated state, the pore volume percentage in the rock sample is determined.

[0085] Here, before determining the volume of water in the rock sample in the water-saturated state based on the difference between the first nuclear magnetic resonance T2 spectrum signal and the third nuclear magnetic resonance T2 spectrum signal, the nuclear magnetic resonance T2 spectrum signal corresponding to the water samples with different volumes can be obtained to fit the fitting relationship between the nuclear magnetic resonance T2 spectrum signal and the water sample volume: S w =K w V w .

[0086] Among them, S w Represents the NMR T2 spectrum signal corresponding to the water sample, dimensionless, K w represents the slope of the fit, dimensionless, V w Represents the volume of the water sample. For example, in the embodiment of the present invention, the volume of the water sample V w The unit is milliliters.

[0087] It should be noted that when obtaining the NMR T2 spectrum signal corresponding to different volumes of water samples, the experimental environment is the same as the experimental environment for obtaining the first NMR T2 spectrum signal and the third NMR T2 spectrum signal, both of which are preset pressure and preset temperature. Moreover, the water sample here is the same as the water sample used in the above-mentioned vacuum saturated water extraction.

[0088] On the basis of obtaining the above fitting relationship, the NMR T2 spectrum signal quantity corresponding to the water sample in the rock sample in the water-saturated state can be determined based on the difference between the first NMR T2 spectrum signal quantity and the third NMR T2 spectrum signal quantity. Based on the above fitting relationship, the volume of water in the rock sample in the water-saturated state is determined. The specific calculation formula can be expressed as:

[0089] Wherein, V1 represents the volume of water in the rock sample in a water-saturated state, S1 represents the first nuclear magnetic resonance T2 spectrum signal, and S3 represents the third nuclear magnetic resonance T2 spectrum signal.

[0090] In the embodiment of the present invention, the pore volume ratio in the rock sample refers to the ratio between the pore volume in the rock sample and the volume of the rock sample. The volume of water in the rock sample in a water-saturated state can be used to characterize the pore volume in the rock sample. Therefore, the embodiment of the present invention can determine the pore volume ratio in the rock sample based on the volume of water in the rock sample in a water-saturated state and the volume of the rock sample after vacuum degassing and drying.

[0091] Here, the pore volume fraction in the rock sample can be expressed as:

[0092] Among them, E p Indicates the pore ratio in the rock sample, V y Represents the volume of the rock sample after vacuum degassing and drying.

[0093] Step 202, based on the pore volume percentage, the first nuclear magnetic resonance T2 spectrum signal quantity and the second nuclear magnetic resonance T2 spectrum signal quantity, respectively determine the pore percentage corresponding to different relaxation times of the rock sample in the water saturated state and the pore percentage corresponding to different relaxation times of the rock sample in the water flooding state.

[0094] In some embodiments, the pore fractions of the rock sample in the water-saturated state corresponding to different relaxation times can be determined based on the ratio between the pore fraction and the first nuclear magnetic resonance T2 spectrum signal. Correspondingly, the pore fractions of the rock sample in the water-flooded state corresponding to different relaxation times can be determined based on the ratio between the pore fraction and the second nuclear magnetic resonance T2 spectrum signal.

[0095] Here, the pore proportion of rock samples in a water-saturated state at different relaxation times can be expressed as:

[0096] Among them, E 1i represents the pore ratio of the rock sample in the water-saturated state at relaxation time i, S 1i It represents the NMR T2 spectrum signal corresponding to the relaxation time i of the rock sample in the water saturated state.

[0097] Here, the nuclear magnetic resonance T2 spectrum of the rock sample in the water-saturated state contains nuclear magnetic resonance T2 spectrum signal amounts corresponding to different relaxation times, and the spectral area of ​​the nuclear magnetic resonance T2 spectrum of the rock sample in the water-saturated state is the above-mentioned first nuclear magnetic resonance T2 spectrum signal amount.

[0098] Here, the pore proportion of rock samples under water flooding state at different relaxation times can be expressed as:

[0099]

[0100] Among them, E2i It represents the pore ratio of the rock sample under water flooding state when the relaxation time is i, S 2i It represents the NMR T2 spectrum signal corresponding to the relaxation time i of the rock sample in the water-flooding state.

[0101] Here, the nuclear magnetic resonance T2 spectrum of the rock sample in the water-flooding state contains nuclear magnetic resonance T2 spectrum signal amounts corresponding to different relaxation times, and the spectral area of ​​the nuclear magnetic resonance T2 spectrum of the rock sample in the water-flooding state is the above-mentioned second nuclear magnetic resonance T2 spectrum signal amount.

[0102] Step 203, determining the critical relaxation time based on the pore proportions corresponding to different relaxation times of the rock sample in the water-saturated state and the rock sample in the water-flooding state.

[0103] In some embodiments, when determining the critical relaxation time, the cumulative pore proportion of the rock sample in the saturated water state corresponding to different relaxation times can be determined based on the pore proportion of the rock sample in the saturated water state at different relaxation times, thereby obtaining a curve diagram between the relaxation time and the cumulative pore proportion, that is, the first curve. Here, the first curve is used to characterize the cumulative pore proportion of the rock sample in the saturated water state at different relaxation times. Correspondingly, based on the pore proportion of the rock sample in the flooding water state at different relaxation times, the cumulative pore proportion of the rock sample in the flooding water state at different relaxation times is determined, thereby obtaining a curve diagram between the relaxation time and the cumulative pore proportion, that is, the second curve. Here, the second curve is used to characterize the cumulative pore proportion of the rock sample in the flooding water state at different relaxation times.

[0104] See also Figure 3 , Figure 3 A first curve corresponding to the saturated water state and a second curve corresponding to the water-displacement state are shown. When the curvature of the second curve is zero, a tangent line corresponding to the second curve is obtained, the intersection point of the tangent line and the first curve is determined, and the relaxation time corresponding to the intersection point is determined as the critical relaxation time.

[0105] Step 204, determining the pores with a relaxation time greater than the critical relaxation time as gas-containing pores in the rock sample, and determining the pores with a relaxation time less than the critical relaxation time as water-containing pores in the rock sample.

[0106] Based on the critical relaxation time, the embodiment of the present invention can divide the pores in the rock sample into water-containing pores and gas-containing pores, so that the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores can be correspondingly determined based on the single fractal theory, thereby determining the gas-water relative wettability characteristics of the rock sample.

[0107] In the embodiment of the present invention, the water-containing pore fractal dimension value corresponding to the water-containing pores and the air-containing pore fractal dimension value corresponding to the air-containing pores can be determined based on the nuclear magnetic resonance single fractal theory.

[0108] The single fractal theory of NMR can be expressed as:

[0109] lg(E zi )=(3-D)lg(i)+(D-3)lgT 2max

[0110] Its simplified form can be expressed as: lg(E zi )=(D-3)lg(i).

[0111] Among them, E zi represents the cumulative pore ratio corresponding to relaxation time i, D represents the single fractal dimension value, T 2max represents the maximum relaxation time.

[0112] For water-containing pores, the cumulative pore proportions corresponding to water-containing pores at different relaxation times are substituted into the above simplified formula for fitting, and the single fractal dimension value D can be obtained. The single fractal dimension value at this time is the fractal dimension value of water-containing pores corresponding to the water-containing pores.

[0113] For gas-containing pores, the cumulative pore proportions corresponding to gas-containing pores at different relaxation times are substituted into the above simplified formula for fitting, and the single fractal dimension value D can be obtained. The single fractal dimension value at this time is the fractal dimension value of gas-containing pores corresponding to the gas-containing pores.

[0114] Alternatively, the cumulative pore fraction corresponding to different relaxation times can be plotted by lg(i)-lg(E zi ) point-line diagram. The least square method is used to fit the above point-line diagram in sections, and the corresponding fractal dimension values ​​of water-bearing pores and gas-bearing pores are obtained.

[0115] For example, see Figure 4 , Figure 4 It shows that lg(i)-lg(E zi ) dot-line graph. For water-bearing pores, lg(E zi )=0.7422lg(i)+0.7153. Correspondingly, the fractal dimension value of water-bearing pores D w =0.7422+3=3.7422. Here, R 2 =0.496. 2 refers to the linear fitting curve correlation, R 2 The larger it is, the better the linear fitting curve correlation is.

[0116] For gas-containing pores, lg(Ezi )=0.0132lg(i)+1.5025. Correspondingly, the fractal dimension value of gas-bearing pores D g =0.0132+3=3.0132. Here, R 2 =0.8712.

[0117] In the embodiment of the present invention, on the basis of obtaining the fractal dimension values ​​of water-containing pores and the fractal dimension values ​​of gas-containing pores, the gas-water relative wettability characteristics of the rock sample are further determined.

[0118] When determining the relative wettability characteristics of gas and water, the relative gas affinity index and relative water affinity index of the rock sample are first determined based on the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores, respectively.

[0119] In some embodiments, the Determine the relative gas affinity index in rock samples and use Determine the relative hydrophilicity index in rock samples.

[0120] Among them, I xg Relative affinity index, D g represents the fractal dimension of gas-bearing pores, D w represents the fractal dimension of water-bearing pores, I xw Relative hydrophilicity index.

[0121] The air-water relative wettability characteristics can include relatively air-philic, relatively hydrophilic, or air-water amphiphilic.

[0122] In the embodiment of the present invention, the relative wettability characteristics of gas and water of the rock sample are determined based on the relative hydrophilicity index and relative air affinity index of the rock sample. When the relative air affinity index is greater than a first preset value and the relative hydrophilicity index is less than a second preset value, the rock sample is determined to be relatively air-friendly; when the relative air affinity index is less than the second preset value and the relative hydrophilicity index is greater than the first preset value, the rock sample is determined to be relatively hydrophilic; when the relative air affinity index and the relative hydrophilicity index are both greater than or equal to the second preset value and less than or equal to the first preset value, the rock sample is determined to be both air-friendly and water-friendly.

[0123] Here, the first preset value is used to characterize the relative gas affinity coefficient corresponding to the gas accumulation in the tight sandstone gas reservoir, and the second preset value is used to characterize the relative gas affinity coefficient corresponding to the gas accumulation in the tight sandstone. Among them, the first preset value and the second preset value can be determined according to the contact angle method. When determining the values ​​of the first preset value and the second preset value, the relative wettability of the rock sample can be measured by the above-mentioned gas-water relative wettability measurement method and the contact angle method, respectively, so as to determine the values ​​of the above-mentioned first preset value and the second preset value. In the contact angle method, when the contact angle is in the range of 0 to 75°, the rock sample is determined to be relatively hydrophilic. When the contact angle is in the range of 75° to 105°, the rock sample is determined to be mixed wet. When the contact angle is greater than 105°, the rock sample is determined to be hydrophobic. For the measurement of gas-water relative wettability, mixed wettability can be understood as gas-water amphiphilic. Hydrophobicity can be understood as relative gas affinity.

[0124] Based on the contact angles and relative hydrophilicity index and relative air affinity index corresponding to different rock samples, the relative hydrophilicity index and relative air affinity index corresponding to the rock sample when it is relatively hydrophilic, the relative hydrophilicity index and relative air affinity index corresponding to the rock sample when it is air-water amphiphilic, and the relative hydrophilicity index and relative air affinity index corresponding to the rock sample when it is relatively air-philic can be determined accordingly. Thus, the above-mentioned first preset value and the second preset value are determined.

[0125] See also Figure 5 and Figure 6 , Figure 5 The fitting curve between the contact angle and the relative hydrophilicity index is shown. Figure 6 The fitting curve between the contact angle and the relative air affinity index is shown. The first preset value and the second preset value can be determined according to the fitting curve. For example, the first preset value can be 0.6, and the second preset value can be 0.4.

[0126] The embodiment of the present invention determines the relative hydrophilicity index and the relative gas affinity index of the rock sample, thereby accurately measuring the relative wettability of gas and water in the tight sandstone gas reservoir.

[0127] It should be understood that the order of execution of the steps in the above embodiment does not necessarily mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0128] The following is an embodiment of the device of the present invention. For details not described in detail therein, reference may be made to the corresponding method embodiment described above.

[0129] Figure 7 The schematic diagram of the structure of the device for measuring relative wettability of air and water provided in an embodiment of the present invention is shown. For the convenience of description, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0130] like Figure 7 As shown, the device 7 for measuring relative wettability of air and water includes: a measuring module 71 and a calculating module 72 .

[0131] The measuring module 71 is used for:

[0132] Obtaining a rock sample, performing a vacuum saturated water treatment on the relative gas affinity index rock sample to obtain a rock sample in a saturated water state, and obtaining a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state;

[0133] Performing gas water flooding treatment on a rock sample in a water-saturated state according to a relative gas affinity index to obtain a rock sample in a water-flooded state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooded state;

[0134] The calculation module 72 is used for:

[0135] Based on the relative gas affinity index first nuclear magnetic resonance T2 spectrum signal quantity and the relative gas affinity index second nuclear magnetic resonance T2 spectrum signal quantity, water-bearing pores and gas-bearing pores in the relative gas affinity index rock sample are determined;

[0136] Determine the water-containing pore fractal dimension value corresponding to the water-containing pores with relative air affinity index, and the air-containing pore fractal dimension value corresponding to the air-containing pores with relative air affinity index;

[0137] Based on the relative gas affinity index water-containing pore fractal dimension values ​​and the relative gas affinity index gas-containing pore fractal dimension values, the gas-water relative wettability characteristics of the relative gas affinity index rock sample are determined.

[0138] In a possible implementation, the calculation module 72 is specifically configured to:

[0139] Based on the relative gas affinity index first nuclear magnetic resonance T2 spectrum signal, determine the pore volume ratio in the relative gas affinity index rock sample;

[0140] Based on the pore volume percentage of the relative gas affinity index, the first nuclear magnetic resonance T2 spectrum signal of the relative gas affinity index, and the second nuclear magnetic resonance T2 spectrum signal of the relative gas affinity index, the pore percentage of the rock sample in the water-saturated state corresponding to different relaxation times and the pore percentage of the rock sample in the water-flooding state corresponding to different relaxation times are determined respectively;

[0141] Determine the critical relaxation time based on the pore proportions corresponding to different relaxation times of rock samples in a water-saturated state and a water-flooded state;

[0142] The pores with a relaxation time greater than the critical relaxation time of the relative gas affinity index are determined as gas-containing pores in the rock sample, and the pores with a relaxation time less than the critical relaxation time of the relative gas affinity index are determined as water-containing pores in the rock sample.

[0143] In a possible implementation, the calculation module 72 is specifically configured to:

[0144] Based on the pore proportions of the rock sample in the water-saturated state at different relaxation times, a first curve is determined; the first curve of the relative gas affinity index is used to characterize the cumulative pore proportions of the rock sample in the water-saturated state at different relaxation times;

[0145] Based on the pore proportions of the rock samples under the water flooding state corresponding to different relaxation times, the second curve is determined; the relative gas affinity index second curve is used to characterize the cumulative pore proportions of the rock samples under the water flooding state corresponding to different relaxation times;

[0146] When the curvature of the second relative air affinity index curve is zero, the tangent corresponding to the second relative air affinity index curve is obtained, the intersection of the relative air affinity index tangent and the first relative air affinity index curve is determined, and the relaxation time corresponding to the intersection of the relative air affinity index is determined as the critical relaxation time of the relative air affinity index.

[0147] In a possible implementation, the calculation module 72 is specifically configured to:

[0148] Based on the relative gas affinity index water-bearing pore fractal dimension value and the relative gas affinity index gas-bearing pore fractal dimension value, the relative gas affinity index and relative water affinity index of the relative gas affinity index rock sample are determined respectively;

[0149] When the relative gas affinity index relative gas affinity index is greater than a first preset value, and the relative gas affinity index relative water affinity index is less than a second preset value, determining that the relative gas affinity index rock sample is relatively gas-affinity;

[0150] When the relative air affinity index relative air affinity index is less than the second preset value, and the relative air affinity index relative hydrophilic index is greater than the first preset value, determining that the relative air affinity index rock sample is relatively hydrophilic;

[0151] When the relative gas affinity index relative gas affinity index and the relative gas affinity index relative water affinity index are both greater than or equal to the second preset value and less than or equal to the first preset value, the relative gas affinity index rock sample gas-water affinity is determined.

[0152] In a possible implementation, the calculation module 72 is specifically configured to:

[0153] Performing vacuum degassing and drying treatment on the rock sample with relative gas affinity index, and obtaining the third nuclear magnetic resonance T2 spectrum signal quantity corresponding to the rock sample after vacuum degassing and drying treatment;

[0154] Determine the volume of water in the rock sample in a relative gas affinity index water-saturated state based on the difference between the relative gas affinity index first nuclear magnetic resonance T2 spectrum signal and the relative gas affinity index third nuclear magnetic resonance T2 spectrum signal;

[0155] Based on the volume of water in the rock sample in the water-saturated state of the relative gas affinity index, the pore volume ratio in the rock sample with the relative gas affinity index is determined.

[0156] In a possible implementation, the calculation module 72 is specifically configured to:

[0157] Based on the pore volume percentage of the relative gas affinity index, the first nuclear magnetic resonance T2 spectrum signal of the relative gas affinity index, and the second nuclear magnetic resonance T2 spectrum signal of the relative gas affinity index, the pore percentage of the rock sample in the water-saturated state corresponding to different relaxation times and the pore percentage of the rock sample in the water-flooding state corresponding to different relaxation times are determined respectively;

[0158] Based on the ratio between the pore ratio of relative gas affinity index and the signal of the first nuclear magnetic resonance T2 spectrum of relative gas affinity index, the pore ratio of the rock sample in the water saturated state corresponding to different relaxation times is determined;

[0159] Based on the ratio between the pore proportion of the relative gas affinity index and the signal of the second nuclear magnetic resonance T2 spectrum of the relative gas affinity index, the pore proportion of the rock sample in the water-flooding state corresponding to different relaxation times is determined.

[0160] In a possible implementation, the calculation module 72 is specifically configured to:

[0161] according to Determine the relative affinity index relative affinity index;

[0162] according to Determine the relative air affinity index and the relative hydrophilicity index;

[0163] Among them, I xg Relative affinity index, D g Represents the relative air affinity index and fractal dimension of air-bearing pores, D w Represents the relative air affinity index water-containing pore fractal dimension value, I xw Relative hydrophilicity index.

[0164] In the embodiment of the present invention, the calculation module 72 determines the water-containing pores and gas-containing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in a water-saturated state and the second nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in a water-displaced state, and obtains the relative wettability characteristics of gas and water in the rock sample by determining the fractal dimension values ​​of the water-containing pores and the fractal dimension values ​​of the gas-containing pores. The calculation module 72 detects the distribution characteristics of different hydrogen-containing fluids in the pores inside the rock sample through the first nuclear magnetic resonance T2 spectrum signal and the second nuclear magnetic resonance T2 spectrum signal, and divides the storage space of the gas-water two-phase fluid thereby dividing the pores in the rock sample into water-containing pores and gas-containing pores. On this basis, calculation module 72 can characterize the wettability characteristics of different types of pores inside the rock sample through the fractal dimension values ​​of water-containing pores and gas-containing pores, and then determine the gas-water relative wettability characteristics of the rock sample, and finally achieve accurate measurement of the gas-water relative wettability characteristics of the rock sample, so as to facilitate the subsequent accurate exploration and development of tight sandstone gas reservoirs.

[0165] Figure 8 Schematic diagram of an electronic device provided by an embodiment of the present invention. Figure 8 As shown, the electronic device 8 of this embodiment includes: a processor 80, a memory 81, and a computer program 82 stored in the memory 81 and executable on the processor 80. When the processor 80 executes the computer program 82, the steps in the above-mentioned gas-water relative wettability measurement method embodiments are implemented, for example Figure 1 Alternatively, when the processor 80 executes the computer program 82, the functions of each module / unit in the above-mentioned device embodiments are realized, for example, Figure 7 The functions of modules 71 to 72 are shown.

[0166] Exemplarily, the computer program 82 may be divided into one or more modules / units, which are stored in the memory 81 and executed by the processor 80 to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program 82 in the electronic device 8. For example, the computer program 82 may be divided into Figure 7 Modules 71 to 72 are shown.

[0167] The electronic device 8 may be a computing device such as a desktop computer, a notebook, a PDA, or a cloud server. The electronic device 8 may include, but is not limited to, a processor 80 and a memory 81. Those skilled in the art will appreciate that Figure 8It is only an example of the electronic device 8 and does not constitute a limitation of the electronic device 8. It may include more or fewer components than shown in the figure, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0168] The processor 80 may 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. A general-purpose processor may be a microprocessor or any conventional processor, etc.

[0169] The memory 81 may be an internal storage unit of the electronic device 8, such as a hard disk or memory of the electronic device 8. The memory 81 may also be an external storage device of the electronic device 8, such as a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card, etc. equipped on the electronic device 8. Further, the memory 81 may also include both an internal storage unit and an external storage device of the electronic device 8. The memory 81 is used to store the computer program and other programs and data required by the electronic device. The memory 81 may also be used to temporarily store data that has been output or is to be output.

[0170] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0171] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0172] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0173] In the embodiments provided by the present invention, it should be understood that the disclosed devices / electronic devices and methods can be implemented in other ways. For example, the device / electronic device embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0174] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0175] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0176] If the integrated module / unit 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. When the computer program is executed by the processor, the steps of the above-mentioned gas-water relative wettability measurement method embodiments can be implemented. 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 that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electrical carrier signal, telecommunication signal and software distribution medium. The embodiments described above are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A method for measuring relative wettability of air and water, characterized in that: include: Obtaining a rock sample, performing a vacuum saturated water treatment on the rock sample to obtain a rock sample in a saturated water state, and obtaining a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state; Performing gas water flooding treatment on the rock sample in the water-saturated state to obtain a rock sample in the water-flooding state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooding state; Determining water-bearing pores and gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount; respectively determining the water-containing pore fractal dimension values ​​corresponding to the water-containing pores and the air-containing pore fractal dimension values ​​corresponding to the air-containing pores; Determining the gas-water relative wettability characteristics of the rock sample based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value; Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, determining the gas-water relative wettability characteristics of the rock sample includes: Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample; When the relative affinity for air index is greater than a first preset value, and the relative affinity for water index is less than a second preset value, determining that the rock sample is relatively affinity for air; When the relative air affinity index is less than the second preset value, and the relative water affinity index is greater than the first preset value, it is determined that the rock sample is relatively hydrophilic; When the relative air affinity index and the relative water affinity index are both greater than or equal to the second preset value and less than or equal to the first preset value, determining the gas-water affinity of the rock sample; Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample, including: according to Determining the relative affinity index; according to Determining the relative hydropathic index; Among them, I xg Denotes the relative affinity index, D g represents the fractal dimension value of the gas-containing pores, D w represents the fractal dimension value of the water-containing pores, I xw It represents the relative hydropathic index.

2. The method for measuring relative wettability of air and water according to claim 1, characterized in that: The step of determining the water-bearing pores and the gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal quantity and the second nuclear magnetic resonance T2 spectrum signal quantity comprises: Determining the pore volume ratio in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal; Based on the pore volume percentage, the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount, respectively determine the pore percentage corresponding to different relaxation times of the rock sample in a water-saturated state and the pore percentage corresponding to different relaxation times of the rock sample in a water-flooding state; Determine the critical relaxation time based on the pore proportions corresponding to different relaxation times of rock samples in a water-saturated state and a water-flooded state; The pores with a relaxation time greater than the critical relaxation time are determined as gas-containing pores in the rock sample, and the pores with a relaxation time less than the critical relaxation time are determined as water-containing pores in the rock sample.

3. The method for measuring relative wettability of air and water according to claim 2, characterized in that: Based on the pore proportions of rock samples in a saturated water state and a water-flooded water state at different relaxation times, the critical relaxation time is determined, including: Determine a first curve based on the pore proportions of the rock sample in a water-saturated state corresponding to different relaxation times; the first curve is used to characterize the cumulative pore proportions of the rock sample in a water-saturated state corresponding to different relaxation times; Determine a second curve based on the pore proportions of the rock sample under the water flooding state corresponding to different relaxation times; the second curve is used to characterize the cumulative pore proportions of the rock sample under the water flooding state corresponding to different relaxation times; When the curvature of the second curve is zero, a tangent line corresponding to the second curve is obtained, an intersection point between the tangent line and the first curve is determined, and a relaxation time corresponding to the intersection point is determined as the critical relaxation time.

4. The method for measuring relative wettability of air and water according to claim 2 or 3, characterized in that: Determining the pore volume ratio in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal includes: Performing vacuum degassing and drying treatment on the rock sample, and obtaining a third nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample after the vacuum degassing and drying treatment; Determining the volume of water in the rock sample in the water-saturated state based on the difference between the first nuclear magnetic resonance T2 spectrum signal amount and the third nuclear magnetic resonance T2 spectrum signal amount; Based on the volume of water in the rock sample in the water-saturated state, the pore volume fraction in the rock sample is determined.

5. The method for measuring relative wettability of air and water according to claim 2 or 3, characterized in that: Based on the pore volume percentage, the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount, the pore percentages corresponding to different relaxation times of the rock sample in a water-saturated state and the pore percentages corresponding to different relaxation times of the rock sample in a water-flooding state are determined respectively, including: Based on the ratio between the pore fraction and the first nuclear magnetic resonance T2 spectrum signal, determining the pore fraction corresponding to different relaxation times of the rock sample in a water-saturated state; Based on the ratio between the pore fraction and the signal quantity of the second nuclear magnetic resonance T2 spectrum, the pore fraction of the rock sample under the water flooding state corresponding to different relaxation times is determined.

6. A device for measuring relative wettability of air and water, characterized in that: include: Measurement modules for: Obtaining a rock sample, performing a vacuum saturated water treatment on the rock sample to obtain a rock sample in a saturated water state, and obtaining a first nuclear magnetic resonance T2 spectrum signal corresponding to the rock sample in the saturated water state; Performing gas water flooding treatment on the rock sample in the water-saturated state to obtain a rock sample in the water-flooding state, and obtaining a second nuclear magnetic resonance T2 spectrum signal amount corresponding to the rock sample in the water-flooding state; Compute module for: Determining water-bearing pores and gas-bearing pores in the rock sample based on the first nuclear magnetic resonance T2 spectrum signal amount and the second nuclear magnetic resonance T2 spectrum signal amount; respectively determining the water-containing pore fractal dimension values ​​corresponding to the water-containing pores and the air-containing pore fractal dimension values ​​corresponding to the air-containing pores; Determining the gas-water relative wettability characteristics of the rock sample based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value; Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, determining the gas-water relative wettability characteristics of the rock sample includes: Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample; When the relative affinity for air index is greater than a first preset value, and the relative affinity for water index is less than a second preset value, determining that the rock sample is relatively affinity for air; When the relative air affinity index is less than the second preset value, and the relative water affinity index is greater than the first preset value, it is determined that the rock sample is relatively hydrophilic; When the relative air affinity index and the relative water affinity index are both greater than or equal to the second preset value and less than or equal to the first preset value, determining the gas-water affinity of the rock sample; Based on the water-containing pore fractal dimension value and the gas-containing pore fractal dimension value, respectively determining a relative gas affinity index and a relative water affinity index of the rock sample, including: according to Determining the relative affinity index; according to Determining the relative hydropathic index; Among them, I xg Denotes the relative affinity index, D g represents the fractal dimension value of the gas-containing pores, D w represents the fractal dimension value of the water-containing pores, I xw It represents the relative hydropathic index.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for measuring the relative wettability of air and water as described in any one of claims 1 to 5 are implemented.

8. 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 for measuring the relative wettability of air and water as described in any one of claims 1 to 5 are implemented.

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