Method, device, electronic equipment and medium for calculating critical migration velocity of oil-gas interface

Abstract

Disclosed are a method, device, electronic device and medium for calculating the critical migration velocity of an oil-gas interface. The method may include: establishing an unequal diameter parallel capillary model to obtain a calculation formula for the critical interface migration velocity; dividing multiple reservoir types according to pore size; and calculating the critical interface migration velocity of each reservoir type according to the calculation formula. The present invention determines the critical migration velocity of the oil-gas interface by gas injection stable gravity drive through the quantitative analysis results of microscopic pore structure and the calculation formula for the mobilizable pore limit by gas injection stable gravity drive, combines the critical interface migration velocity with the minimum flow limit of pore throats, and mobilizes the vast majority of the pore throat residual oil while maintaining the stable migration of the oil-gas interface, thereby improving the recovery rate of the reservoir.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas field development engineering, and more specifically, to a method, device, electronic equipment and medium for calculating the critical migration velocity of an oil and gas interface. Background Art

[0002] Top gas injection gravity drive technology is a common gas drive technology for improving oil recovery, and has a long history of application in the oil extraction industry. Since oil reservoirs often have strong heterogeneity and anisotropy, and the viscosity of gas is lower than that of crude oil, the injected gas in conventional gas drive technology tends to be preferentially advanced along a single layer or in a direction with stronger permeability. The top gas injection gravity drive technology effectively utilizes the gravity separation effect of gas, transforming conventional horizontal displacement into vertical displacement, so as to increase the swept volume of gas and improve oil recovery.

[0003] Determining the critical migration velocity of the oil-gas interface in the reservoir is the key to the top gas injection gravity drive technology. If the gas injection velocity is too high, it will affect the stability of the oil-gas interface migration, accelerate the formation of displacement gas fingering and tongue advancement, and the gas will break through prematurely, thereby reducing the gas injection effect. At present, the existing technology uses methods such as the Dietz model to determine the critical velocity of interface stability and verify whether the results calculated by the model can guarantee the stability of the oil-gas interface. The traditional method can calculate the critical migration velocity, but at this velocity, the remaining oil in some small and medium pores cannot be mobilized, resulting in a low overall recovery rate of the reservoir.

[0004] Therefore, it is necessary to develop a method, device, electronic equipment and medium for calculating the critical migration velocity of the oil-gas interface.

[0005] The information disclosed in the background technology section of the present invention is only intended to deepen the understanding of the general background technology of the present invention, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0006] The present invention proposes a method, device, electronic equipment and medium for calculating the critical migration velocity of the oil-gas interface, which can determine the critical migration velocity of the oil-gas interface in gas injection stable gravity drive through quantitative analysis results of microscopic pore structure and a calculation formula for the mobilizable pore limit in gas injection stable gravity drive, and combine the critical interface migration velocity with the minimum flow limit of pore throats, so as to mobilize most of the remaining oil in the pore throats while maintaining the stable migration of the oil-gas interface and improve the recovery rate of the reservoir.

[0007] In a first aspect, an embodiment of the present disclosure provides a method for calculating the critical migration velocity of an oil-gas interface, comprising:

[0008] A capillary model with unequal diameters in parallel was established to obtain the calculation formula of critical interface migration velocity;

[0009] There are multiple reservoir types based on pore size;

[0010] The critical interface migration velocity of each reservoir type is calculated according to the calculation formula.

[0011] Preferably, the calculation formula of the critical interface migration velocity is:

[0012]

[0013] Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, r2 is the maximum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the viscosities of gas and oil respectively, and g is the acceleration due to gravity.

[0014] Preferably, the multiple reservoir types include: microporous reservoir, small pore reservoir, medium pore reservoir and macroporous reservoir.

[0015] Preferably, calculating the critical interface migration velocity of each reservoir type according to the calculation formula includes:

[0016] Calculate the average pore throat distribution characteristic curve of each reservoir type, calculate the volume fraction and permeability contribution of different pore throats, and then calculate the minimum flow pore throat radius;

[0017] The minimum flow pore throat radius is taken as the minimum pore throat radius;

[0018] The critical interface migration velocity of each reservoir type is calculated according to the calculation formula.

[0019] Preferably, the pore throat radius when the cumulative permeability contribution is 99.95% is the minimum flow pore throat radius.

[0020] Preferably, it also includes:

[0021] The lower limit of the pore throat radius is calculated so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0022] Preferably, the lower limit of the pore throat radius is calculated by formula (2):

[0023]

[0024] Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ oare the gas and oil viscosities respectively, g is the gravitational acceleration, v is the interface migration velocity, and θ is the reservoir inclination.

[0025] As a specific implementation method of the embodiment of the present disclosure,

[0026] In a second aspect, the present disclosure also provides a device for calculating the critical migration velocity of an oil-gas interface, comprising:

[0027] Formula building module, which builds the unequal diameter parallel capillary model and obtains the calculation formula of critical interface migration velocity;

[0028] Reservoir classification module, which divides multiple reservoir types according to pore size;

[0029] The calculation module calculates the critical interface migration velocity of each reservoir type according to the calculation formula.

[0030] Preferably, a capillary model of unequal diameters in parallel is established, and the calculation formula for obtaining the critical interface migration velocity includes:

[0031] According to the unequal diameter parallel capillary model, the lower limit of the pore throat radius is calculated;

[0032] According to the lower limit of the pore throat radius, a calculation formula for the critical interface migration velocity is obtained.

[0033] Preferably, the calculation formula of the critical interface migration velocity is:

[0034]

[0035] Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, r2 is the maximum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the viscosities of gas and oil respectively, and g is the acceleration due to gravity.

[0036] Preferably, the multiple reservoir types include: microporous reservoir, small pore reservoir, medium pore reservoir and macroporous reservoir.

[0037] Preferably, calculating the critical interface migration velocity of each reservoir type according to the calculation formula includes:

[0038] Calculate the average pore throat distribution characteristic curve of each reservoir type, calculate the volume fraction and permeability contribution of different pore throats, and then calculate the minimum flow pore throat radius;

[0039] The minimum flow pore throat radius is taken as the minimum pore throat radius;

[0040] The critical interface migration velocity of each reservoir type is calculated according to the calculation formula.

[0041] Preferably, the pore throat radius when the cumulative permeability contribution is 99.95% is the minimum flow pore throat radius.

[0042] Preferably, it also includes:

[0043] The lower limit of the pore throat radius is calculated so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0044] Preferably, the lower limit of the pore throat radius is calculated by formula (2):

[0045]

[0046] Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities respectively, g is the gravitational acceleration, v is the interface migration velocity, and θ is the reservoir inclination.

[0047] In a third aspect, an embodiment of the present disclosure further provides an electronic device, the electronic device comprising:

[0048] A memory storing executable instructions;

[0049] A processor runs the executable instructions in the memory to implement the method for calculating the critical migration velocity of the oil-gas interface.

[0050] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the method for calculating the critical migration velocity of the oil-gas interface is implemented.

[0051] The methods and apparatus of the present invention have other features and advantages that will be apparent from, or will be described in detail in, the accompanying drawings and subsequent detailed descriptions incorporated herein, which together serve to explain the specific principles of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0053] Figure 1A schematic diagram of a capillary model with unequal diameters connected in parallel is shown according to an embodiment of the present invention.

[0054] Figure 2 A flow chart showing the steps of a method for calculating the critical migration velocity of an oil-gas interface according to an embodiment of the present invention.

[0055] Figure 3 A schematic diagram showing pore throat distribution characteristics of four types of reservoir cores according to an embodiment of the present invention is shown.

[0056] Figure 4 A schematic diagram showing the volume fraction and permeability contribution corresponding to the pore throat radius of a Type I reservoir according to an embodiment of the present invention is shown.

[0057] Figure 5 A schematic diagram showing the cumulative permeability contribution corresponding to the pore throat radius of a Class I reservoir according to an embodiment of the present invention is shown.

[0058] Figure 6 A block diagram of a device for calculating the critical migration velocity of an oil-gas interface according to an embodiment of the present invention is shown.

[0059] Description of reference numerals:

[0060] 201. Formula building module; 202. Reservoir classification module; 203. Calculation module. DETAILED DESCRIPTION

[0061] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein.

[0062] The present invention provides a method for calculating the critical migration velocity of an oil-gas interface, comprising:

[0063] A capillary model with unequal diameters in parallel is established to obtain the calculation formula of the critical interface migration velocity. In one example, the calculation formula of the critical interface migration velocity is:

[0064]

[0065] Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the viscosities of gas and oil respectively, and g is the acceleration due to gravity.

[0066] Multiple reservoir types are classified according to pore size; in one example, the multiple reservoir types include: microporous reservoir, small pore reservoir, medium pore reservoir and large pore reservoir.

[0067] The critical interface migration velocity of each reservoir type is calculated according to a calculation formula. In one example, the critical interface migration velocity of each reservoir type is calculated according to a calculation formula, including: calculating the average pore throat distribution characteristic curve of each reservoir type, calculating the volume fraction and permeability contribution degree corresponding to different pore throats, and then calculating the minimum flow pore throat radius; taking the minimum flow pore throat radius as the minimum pore throat radius; and calculating the critical interface migration velocity of each reservoir type according to the calculation formula.

[0068] In one example, the pore throat radius when the cumulative permeability contribution is 99.95% is taken as the minimum flow pore throat radius.

[0069] Specifically, the obtained capillary pressure curve data are calculated using the J function method to obtain the average pore throat distribution characteristic curves of four types of reservoirs. The capillary pressure curve p of the core sample c and S w Obtained through high pressure constant pressure mercury injection testing.

[0070] The expression of J function is:

[0071]

[0072] Among them, S wn is the normalized saturation of the core, p c is the capillary pressure, σ is the oil-water interfacial tension, K is the rock permeability, φ is the rock porosity, where the standardized saturation is:

[0073]

[0074] Where 0≤S wn ≤1, S w is the core water saturation, S wc is the irreducible water saturation of the core.

[0075] Combined with the oil-water interfacial tension, porosity, permeability, and irreducible water saturation data of the core, the capillary pressure curve p of the core sample measured in the laboratory can be obtained through equations (3) and (4): c and S w The corresponding data points are converted into J function and S wn The corresponding data points.

[0076] In order to obtain the J function relationship, the power function least square method can be applied to fit the data points to obtain the fitting parameters of each core. After taking the arithmetic mean, the average J function curve of the reservoir can be determined.

[0077] The average capillary pressure curve of the reservoir is inversely calculated using the following formula.

[0078]

[0079] Among them, S w =S wc +(1-S wc )S wn .

[0080] Different capillary pressures correspond to different mercury saturations. The capillary pressure curve is transformed into a curve of the relationship between volume fraction and pore radius.

[0081] According to the Wall method, the volume fraction and permeability contribution of different pore throats are calculated as follows:

[0082]

[0083] ∑K=∑ΔK (7)

[0084] In the formula, ΔK i is the permeability contribution value of the i-th interval, ∑K is the cumulative permeability contribution degree, and i is the serial number of the interval with equal pore volume; r i is the corresponding pore radius.

[0085] The pore throat radius when the cumulative permeability contribution is 99.95% is taken as the minimum flow pore throat radius. According to the relationship between the permeability contribution and the pore throat radius, the minimum flow pore throat radius of the four types of reservoirs can be determined. The minimum flow pore throat radius is taken as the minimum pore throat radius, and then it is substituted into formula (1) to calculate the critical interface migration velocity of different reservoir types.

[0086] In one example, the method further includes: calculating the lower limit of the pore throat radius so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0087] In one example, the lower limit of the pore throat radius is calculated by formula (2):

[0088]

[0089] Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities respectively, g is the gravitational acceleration, v is the interface migration velocity, and θ is the reservoir inclination.

[0090] Figure 1 A schematic diagram of a capillary model with unequal diameters connected in parallel is shown according to an embodiment of the present invention.

[0091] Specifically, it is assumed that in the process of gas displacement, the dissolution of gas in crude oil is ignored, the two phases are immiscible, the gas is a compressible fluid, and the oil is an incompressible fluid. When the density of oil and gas and the capillary inclination (gravity) are considered, the capillary bundle model is simplified to two parallel capillaries of unequal diameters, such as Figure 1 shown.

[0092] The resultant forces of the oil columns in two parallel capillaries of unequal diameters are:

[0093] The resultant force of the oil column oil1 in radius r1 is:

[0094]

[0095] The resultant force of the gas column gas1 in radius r2 is:

[0096]

[0097] During the process of gas injection stable gravity drive, the oil-gas interface is relatively static, that is, the movement process of the oil column oil1 and the gas column gas1 in the two parallel capillaries is consistent. Therefore, they are subject to the same resultant force and the same movement speed, that is, p F1 =p F2 , v1=v2, and substituting it into equations (8) and (9), we can obtain the height difference of the oil-gas interface, namely:

[0098]

[0099] Where σ is the gas-oil interfacial tension, α1 and α2 are the gas-oil interface wetting angles in capillary 1 and capillary 2, r1 and r2 are the radii of capillary 1 and capillary 2, and ρ g , o are respectively the gas and oil densities, μ g , μ o are respectively the viscosity of gas and oil, g is the acceleration of gravity, p 1g 、p 2g are the gas phase pressure at the gas-oil interface of capillary 1 and capillary 2, respectively, p 1o 、p 2o are the oil phase pressure at the gas-oil interface of capillary 1 and capillary 2, respectively.

[0100] If equation (10) is to be meaningful, the denominator should be greater than 0, that is:

[0101]

[0102] Then, the lower limit of the pore throat radius can be calculated as formula (2). Only when the pore radius of the capillary is greater than r1, the crude oil in the capillary can be mobilized. That is, formula (2) can calculate the radius of the small pores that can be mobilized at a certain oil-gas interface migration velocity when large pores exist. The minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0103] The present invention also provides a device for calculating the critical migration velocity of an oil-gas interface, comprising:

[0104] The formula building module builds a capillary model with unequal diameters in parallel and obtains the calculation formula of the critical interface migration velocity. In one example, the calculation formula of the critical interface migration velocity is:

[0105]

[0106] Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the viscosities of gas and oil respectively, and g is the acceleration due to gravity.

[0107] The reservoir classification module divides the reservoir into multiple types according to the pore size; in one example, the multiple reservoir types include: microporous reservoir, small pore reservoir, medium pore reservoir and large pore reservoir.

[0108] The calculation module calculates the critical interface migration velocity of each reservoir type according to the calculation formula. In one example, the calculation of the critical interface migration velocity of each reservoir type according to the calculation formula includes: calculating the average pore throat distribution characteristic curve of each reservoir type, calculating the correspondence and permeability contribution of different pore throats, and then calculating the minimum flow pore throat radius; taking the minimum flow pore throat radius as the minimum pore throat radius; and calculating the critical interface migration velocity of each reservoir type according to the calculation formula.

[0109] In one example, the pore throat radius when the cumulative permeability contribution is 99.95% is taken as the minimum flow pore throat radius.

[0110] Specifically, the obtained capillary pressure curve data are calculated using the J function method to obtain the average pore throat distribution characteristic curves of four types of reservoirs. The capillary pressure curve p of the core sample c and S w Obtained through high pressure constant pressure mercury injection testing.

[0111] The expression of J function is:

[0112]

[0113] Among them, S wnis the normalized saturation of the core, p c is the capillary pressure, σ is the oil-water interfacial tension, K is the rock permeability, φ is the rock porosity, where the standardized saturation is:

[0114]

[0115] Where 0≤S wn ≤1, S w is the core water saturation, S wc is the irreducible water saturation of the core.

[0116] Combined with the oil-water interfacial tension, porosity, permeability, and irreducible water saturation data of the core, the capillary pressure curve p of the core sample measured in the laboratory can be obtained through equations (3) and (4): c and S w The corresponding data points are converted into J function and S wn The corresponding data points.

[0117] In order to obtain the J function relationship, the power function least square method can be applied to fit the data points to obtain the fitting parameters of each core. After taking the arithmetic mean, the average J function curve of the reservoir can be determined.

[0118] The average capillary pressure curve of the reservoir is inversely calculated using the following formula.

[0119]

[0120] Among them, S w =S wc +(1-S wc )S wn .

[0121] Different capillary pressures correspond to different mercury saturations. The capillary pressure curve is transformed into a curve of the relationship between volume fraction and pore radius.

[0122] According to the Wall method, the volume fraction and permeability contribution of different pore throats are calculated as follows:

[0123]

[0124] ∑K=∑ΔK (7)

[0125] In the formula, ΔK i is the permeability contribution value of the i-th interval, ∑K is the cumulative permeability contribution degree, and i is the serial number of the interval with equal pore volume; r i is the corresponding pore radius.

[0126] The pore throat radius when the cumulative permeability contribution is 99.95% is taken as the minimum flow pore throat radius. According to the relationship between the permeability contribution and the pore throat radius, the values ​​of the minimum flow pore throat radius of the four types of reservoirs can be determined. The minimum flow pore throat radius is taken as the minimum pore throat radius, and then it is substituted into formula (1) to calculate the critical interface migration velocity of different reservoir types.

[0127] In one example, the method further includes: calculating the lower limit of the pore throat radius so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0128] In one example, the lower limit of the pore throat radius is calculated by formula (2):

[0129]

[0130] Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities respectively, g is the gravitational acceleration, v is the interface migration velocity, and θ is the reservoir inclination.

[0131] Figure 1 A schematic diagram of a capillary model with unequal diameters connected in parallel is shown according to an embodiment of the present invention.

[0132] Specifically, it is assumed that in the process of gas displacement, the dissolution of gas in crude oil is ignored, the two phases are immiscible, the gas is a compressible fluid, and the oil is an incompressible fluid. When the density of oil and gas and the capillary inclination (gravity) are considered, the capillary bundle model is simplified to two parallel capillaries of unequal diameters, such as Figure 1 shown.

[0133] The resultant forces of the oil columns in two parallel capillaries of unequal diameters are:

[0134] The resultant force of the oil column oil1 in radius r1 is:

[0135]

[0136] The resultant force of the gas column gas1 in radius r2 is:

[0137]

[0138] During the process of gas injection stable gravity drive, the oil-gas interface is relatively static, that is, the movement process of the oil column oil1 and the gas column gas1 in the two parallel capillaries is consistent. Therefore, they are subject to the same resultant force and the same movement speed, that is, p F1 =p F2 , v1=v2, and substituting it into equations (8) and (9), we can obtain the height difference of the oil-gas interface, namely:

[0139]

[0140] Where σ is the gas-oil interfacial tension, α1 and α2 are the gas-oil interface wetting angles in capillary 1 and capillary 2, r1 and r2 are the radii of capillary 1 and capillary 2, and ρ g , o are respectively the gas and oil densities, μ g , μ o are respectively the viscosity of gas and oil, g is the acceleration of gravity, p 1g 、p 2g are the gas phase pressure at the gas-oil interface of capillary 1 and capillary 2, respectively, p 1o 、p 2o are the oil phase pressure at the gas-oil interface of capillary 1 and capillary 2, respectively.

[0141] If equation (10) is to be meaningful, the denominator should be greater than 0, that is:

[0142]

[0143] Then, the lower limit of the pore throat radius can be calculated as formula (2). Only when the pore radius of the capillary is greater than r1, the crude oil in the capillary can be mobilized. That is, formula (2) can calculate the radius of the small pores that can be mobilized at a certain oil-gas interface migration velocity when large pores exist. The minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0144] The present invention also provides an electronic device, which includes: a memory storing executable instructions; and a processor, which runs the executable instructions in the memory to implement the above-mentioned method for calculating the critical migration velocity of the oil-gas interface.

[0145] The present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the above-mentioned method for calculating the critical migration velocity of the oil-gas interface is implemented.

[0146] To facilitate understanding of the solutions and effects of the embodiments of the present invention, four specific application examples are given below. Those skilled in the art should understand that the examples are only for facilitating understanding of the present invention, and any specific details thereof are not intended to limit the present invention in any way.

[0147] Example 1

[0148] Figure 2 A flow chart showing the steps of a method for calculating the critical migration velocity of an oil-gas interface according to an embodiment of the present invention.

[0149] like Figure 2As shown, the method for calculating the critical migration velocity of the oil-gas interface includes: step 101, establishing an unequal diameter parallel capillary model to obtain a calculation formula for the critical interface migration velocity; step 102, dividing a plurality of reservoir types according to pore size; step 103, calculating the critical interface migration velocity of each reservoir type according to the calculation formula.

[0150] The oil layer temperature of the research object is 65℃, the oil layer pressure is 58.8MPa, and the crude oil density is 940kg / m 3 , viscosity 7.29mPa·s. The injected gas is reservoir associated gas, with a gas density of 1.7415kg / m 3 , viscosity 0.11mPa·s. Gas-oil interfacial tension is 12.5mN / m, gravity acceleration is 9.80m / s 2 The wetting angle is 28° and the inclination angle is 90°. The specific calculation data are shown in Table 1.

[0151] Table 1

[0152]

[0153] The method for determining the critical oil-gas interface migration velocity based on the microscopic heterogeneous pore flow limit is to first use the quantitative analysis results of the microscopic pore structure to obtain the minimum flow pore throat radius of different reservoir types, and then combine the calculation formula of the movable pore limit of gas injection stable gravity drive to determine the critical migration velocity of the oil-gas interface of gas injection stable gravity drive. The calculation steps are as follows:

[0154] Figure 3 A schematic diagram showing pore throat distribution characteristics of four types of reservoir cores according to an embodiment of the present invention is shown.

[0155] Select the capillary pressure curve of the reservoir core to be evaluated, use the J function to calculate the average capillary pressure curve of this type of reservoir, and convert it into a pore throat distribution characteristic curve, such as Figure 3 shown.

[0156] Figure 4 A schematic diagram showing the volume fraction and permeability contribution corresponding to the pore throat radius of a Type I reservoir according to an embodiment of the present invention is shown.

[0157] Figure 5 A schematic diagram showing the cumulative permeability contribution corresponding to the pore throat radius of a Class I reservoir according to an embodiment of the present invention is shown.

[0158] The cumulative permeability contribution under different pore radii is calculated according to formula (6) and formula (7). Taking the type I reservoir as an example, the volume fraction and permeability contribution corresponding to the pore throat radius of the type I reservoir are as follows: Figure 4 As shown in the figure, the cumulative contribution of permeability corresponding to different pore throats is as follows: Figure 5As shown in the figure, the pore throat radius when the cumulative permeability contribution is 99.5% and 99.95% is selected as the main flow pore throat radius r main and minimum flow pore throat radius r min According to this, the lower limit of the main flow pore throat radius of Type I reservoir is 2.45 μm, and the lower limit of the minimum flow pore throat radius is 1.12 μm.

[0159] The results of the main flow and minimum flow pore throat radius for other types of reservoirs are shown in Table 2.

[0160] Table 2

[0161]

[0162] According to formula (1), the minimum pore radius is determined using the minimum flow pore throat lower limit of the four types of reservoirs to obtain the critical interface migration velocity, where r2 is the maximum pore radius; the calculation results are shown in Table 3.

[0163] Table 3

[0164]

[0165] Example 2

[0166] Figure 3 A block diagram of a device for calculating the critical migration velocity of an oil-gas interface according to an embodiment of the present invention is shown.

[0167] like Figure 3 As shown, the oil-gas interface critical migration velocity calculation device comprises:

[0168] Formula establishment module 201, establishes a capillary model of unequal diameters in parallel, and obtains a calculation formula for critical interface migration velocity;

[0169] A reservoir classification module 202, which classifies multiple reservoir types according to pore size;

[0170] The calculation module 203 calculates the critical interface migration velocity of each reservoir type according to the calculation formula.

[0171] As an alternative, the critical interface migration velocity can be calculated as:

[0172]

[0173] Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, r2 is the maximum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ oare the viscosities of gas and oil respectively, and g is the acceleration due to gravity.

[0174] As an option, the multiple reservoir types include: microporous reservoir, small pore reservoir, medium pore reservoir and macroporous reservoir.

[0175] As an alternative, the critical interface migration velocity for each reservoir type is calculated according to the formula including:

[0176] Calculate the average pore throat distribution characteristic curve of each reservoir type, calculate the volume fraction and permeability contribution of different pore throats, and then calculate the minimum flow pore throat radius;

[0177] The minimum flow pore throat radius is taken as the minimum pore throat radius;

[0178] The critical interface migration velocity of each reservoir type is calculated according to the calculation formula.

[0179] As an optional solution, the pore throat radius when the cumulative permeability contribution is 99.95% is taken as the minimum flow pore throat radius.

[0180] As an option, it also includes:

[0181] Calculate the lower limit of the pore throat radius so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

[0182] As an alternative, the lower limit of the pore throat radius can be calculated using formula (2):

[0183]

[0184] Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities respectively, g is the gravitational acceleration, v is the interface migration velocity, and θ is the reservoir inclination.

[0185] Example 3

[0186] The present disclosure provides an electronic device, which includes: a memory storing executable instructions; a processor, which runs the executable instructions in the memory to implement the above-mentioned oil-gas interface critical migration velocity calculation method.

[0187] An electronic device according to an embodiment of the present disclosure includes a memory and a processor.

[0188] The memory is used to store non-temporary computer-readable instructions. Specifically, the memory may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0189] The processor may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions. In one embodiment of the present disclosure, the processor is used to run the computer-readable instructions stored in the memory.

[0190] Those skilled in the art should be able to understand that in order to solve the technical problem of how to obtain a good user experience, the present embodiment may also include well-known structures such as a communication bus and an interface, and these well-known structures should also be included in the protection scope of the present disclosure.

[0191] For detailed description of this embodiment, reference may be made to the corresponding descriptions in the aforementioned embodiments, which will not be repeated here.

[0192] Example 4

[0193] An embodiment of the present disclosure provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method for calculating the critical migration velocity of the oil-gas interface is implemented.

[0194] According to the computer-readable storage medium of the embodiment of the present disclosure, non-transitory computer-readable instructions are stored thereon. When the non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the above-mentioned methods of each embodiment of the present disclosure are executed.

[0195] The above-mentioned computer-readable storage media include, but are not limited to: optical storage media (e.g., CD-ROM and DVD), magneto-optical storage media (e.g., MO), magnetic storage media (e.g., magnetic tape or mobile hard disk), media with built-in rewritable non-volatile memory (e.g., memory card) and media with built-in ROM (e.g., ROM box).

[0196] Those skilled in the art should understand that the purpose of the above description of the embodiments of the present invention is only to exemplarily illustrate the beneficial effects of the embodiments of the present invention, and is not intended to limit the embodiments of the present invention to any given examples.

[0197] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for calculating the critical migration velocity of an oil-gas interface, characterized in that: include: A capillary model with unequal diameters in parallel was established to obtain the calculation formula of critical interface migration velocity; There are multiple reservoir types based on pore size; Calculate the critical interface migration velocity of each reservoir type according to the calculation formula; The calculation formula of the critical interface migration velocity is: Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, r2 is the maximum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities, g is the gravitational acceleration, and θ is the reservoir inclination.

2. The method for calculating the critical migration velocity of the oil-gas interface according to claim 1, wherein: The multiple reservoir types include: microporous reservoirs, small pore reservoirs, medium pore reservoirs and macroporous reservoirs.

3. The method for calculating the critical migration velocity of the oil-gas interface according to claim 1, wherein: The critical interface migration velocity of each reservoir type is calculated according to the calculation formula including: Calculate the average pore throat distribution characteristic curve of each reservoir type, calculate the permeability contribution degree corresponding to different pore throats, and then calculate the minimum flow pore throat radius; The minimum flow pore throat radius is taken as the minimum pore throat radius; The critical interface migration velocity of each reservoir type is calculated according to the calculation formula.

4. The method for calculating the critical migration velocity of the oil-gas interface according to claim 3, wherein: The pore throat radius when the cumulative permeability contribution is 99.95% is the minimum flow pore throat radius.

5. The method for calculating the critical migration velocity of the oil-gas interface according to claim 1, wherein: Also includes: The lower limit of the pore throat radius is calculated so that the minimum pore throat radius is greater than the lower limit of the pore throat radius.

6. The method for calculating the critical migration velocity of the oil-gas interface according to claim 5, wherein: The lower limit of the pore throat radius is calculated by formula (2): Where r' is the lower limit of the pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the viscosities of gas and oil respectively, g is the acceleration of gravity, and v is the interface migration velocity.

7. A device for calculating the critical migration velocity of an oil-gas interface, characterized in that: include: Formula building module, which builds the unequal diameter parallel capillary model and obtains the calculation formula of critical interface migration velocity; Reservoir classification module, which divides multiple reservoir types according to pore size; A calculation module, for calculating the critical interface migration velocity of each reservoir type according to the calculation formula; The calculation formula of the critical interface migration velocity is: Among them, v 界面 is the critical interface migration velocity, r1 is the minimum pore throat radius, r2 is the maximum pore throat radius, ρ g , o are respectively the gas and oil densities, μ g , μ o are the gas and oil viscosities, g is the gravitational acceleration, and θ is the reservoir inclination.

8. An electronic device, characterized in that: The electronic device comprises: A memory storing executable instructions; A processor, wherein the processor runs the executable instructions in the memory to implement the method for calculating the critical migration velocity of the oil-gas interface according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method for calculating the critical migration velocity of the oil-gas interface according to any one of claims 1 to 6 is implemented.

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