Reservoir earthquake rock physical modeling method and system considering fluid miscible phase

Abstract

The invention discloses a reservoir earthquake rock physical modeling method and system considering fluid miscible phase, and the method comprises the steps: obtaining rock matrix mineral components and volume content, giving an initial rock mineral modulus, and constructing a rock matrix model; based on the rock matrix model, utilizing a contact theory to calculate an elastic modulus of a rock skeleton, and constructing a rock skeleton model; and based on the rock skeleton model, calculating the volume modulus and the shear modulus of the saturated rock of the miscible fluid, constructing a saturated rock model of the miscible fluid, and finally obtaining the turbidite sandstone reservoir seismic rock physical model. According to the Batzle-Wang fluid model, the miscible phase condition that the fluid is dissolved at different temperatures and pressures is considered, and the miscible phase fluid is added into the rock physical model, so that the model is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas resource exploration, and in particular to a reservoir seismic rock physics modeling method and system taking fluid miscibility into consideration. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] Turbidite sandstone reservoirs have higher porosity than conventional sandstone reservoirs. Therefore, the modulus change of the fluid in the reservoir will have a greater impact on the elastic parameters of the reservoir. In the actual oil reservoir exploitation process, especially in the process of gas injection, due to the high pore pressure, miscible phases often occur. Fluid miscible phases refer to the dissolution of gas in formation water and oil. Fluid miscible phases will cause changes in the bulk modulus and density of the fluid and reservoir. It causes interference on the time-lapse seismic profile. Therefore, it is particularly important to clarify the changes in reservoir elastic parameters caused by fluid miscible phases. There have been a lot of achievements in the study of miscible phases. The prior art proposes that the magnitude of the interfacial tension can be used to determine whether the reservoir is in a miscible state. Common methods for determining interfacial tension include empirical formulas (such as the Macleod-Sugden correlation) and experimental measurements. The prior art explores the oil recovery efficiency under different pressure conditions through a one-dimensional capillary experiment, and determines the minimum miscible pressure (MMP) based on the efficiency inflection point. There is also a prior art that studies the pressure distribution and the evolution of the miscible state between the injection and production wells through a numerical simulation model, pointing out that MMP is one of the key parameters in the design. Studies have shown that the pressure in the reservoir is not constant. With the continuous injection of gas, the pressure will change, thus affecting the miscibility process between crude oil and injected gas. The prior art has systematically studied the mechanism and influencing factors of oil-gas miscible flooding, and proposed that the reason for the miscibility of injected gas to improve the recovery rate is that the injected gas dissolves in the crude oil to form a miscible phase, which increases the fluidity of the reservoir and thus improves the recovery rate of the reservoir. On a single gas injection well, its production can often be doubled, and the final recovery rate is also improved. There is also prior art that gas flooding has become one of the main methods for improving the recovery rate of low permeability reservoirs due to its good injectability and oil displacement effect. Generally, the injected gas exhibits lower pressure and temperature, and it is in a supercritical state in the formation. Therefore, it exhibits high solubility and high extractability in crude oil, and the lower interfacial tension makes it easy for miscible effects to occur. After gas injection, the viscosity of crude oil decreases and the elastic energy changes. According to laboratory experimental results, when the pressure is greater than 30MPa, the miscibility can reach 100%, and under high pressure conditions, the miscibility is high and the recovery rate is high. In the prior art, based on phase equilibrium theory and reservoir numerical simulation technology, the distribution of components and interfacial tension characteristics of reservoir fluids during gas flooding are studied, and a method for refining the miscible state and sweep coefficient is proposed. The miscible state is further subdivided into four types: fully miscible, partially miscible, nearly miscible and immiscible, and the distinction criteria are given. In the prior art, a pore-scale multiphase and multicomponent flow model is established based on the lattice Boltzmann method (LBM), revealing that the driving pressure difference affects the microscopic distribution of the gas reservoir, making the flow capacity and permeability of the fluid very different. Studies have shown that gas injection miscibility will make the microscopic gas flooding efficiency reach 42% to 94%; and in areas with low water saturation, the high-pressure displacement effect is more significant.

[0004] Conventional rock physics modeling methods use simple fluid uniform mixing and heterogeneous mixing methods for different fluids, which only consider the spatial mixing state of different fluids and fail to characterize in detail the miscible phase conditions such as gas dissolution and oil or formation water. Summary of the invention

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a reservoir seismic rock physics modeling method and system taking into account fluid miscibility. In the process of seismic rock physics modeling of turbidite sandstone reservoirs, the fluid miscibility caused by gas injection production is considered, and the influence of fluid miscibility under different pressure and temperature changes is considered according to the Batzle-Wang fluid model, which provides a new idea for seismic rock physics modeling of turbidite sandstone reservoirs.

[0006] To achieve the above objectives, one or more embodiments of the present invention provide the following technical solutions:

[0007] In a first aspect, the present invention provides a reservoir seismic rock physics modeling method considering fluid miscibility, comprising:

[0008] Obtain the rock matrix mineral components and volume content, and given the initial rock mineral modulus, construct the rock matrix model;

[0009] Based on the rock matrix model, the elastic modulus of the rock skeleton is calculated using contact theory to construct a rock skeleton model;

[0010] Based on the rock skeleton model, the bulk modulus and shear modulus of the rock saturated with the miscible fluid are calculated, a rock model saturated with the miscible fluid is constructed, and finally a seismic rock physics model of the turbidite sandstone reservoir is obtained.

[0011] As a further technical solution, the specific process of the rock matrix model is as follows:

[0012]

[0013] K V =V shale K shale +(1-V shale )V sand

[0014]

[0015]

[0016] G V =V shale G shale +(1-V shale )G sand

[0017]

[0018] Among them, K V represents the equivalent bulk modulus; K R Represents the equivalent bulk modulus; V shale is the mud content; K ma , K sand , K shale are the bulk moduli of the rock matrix, the sandy mineral components that constitute the rock matrix, and the argillaceous mineral components; G V Represents the equivalent shear modulus; G R Represents the equivalent shear modulus; G ma , G sand , G shale They are the shear moduli of the matrix, the sandy mineral component that constitutes the rock matrix, and the muddy mineral component.

[0019] In a further technical solution, the elastic modulus of the rock skeleton is calculated as follows:

[0020]

[0021]

[0022]

[0023] Among them, K eff and G eff are the bulk modulus and shear modulus of the dry rock skeleton, φ is the porosity, P eff is the effective pressure, C is the coordination number, and υ is the Poisson's ratio of the granular mineral.

[0024] A further technical solution is to calculate the bulk modulus and shear modulus of the rock saturated with the miscible fluid as follows:

[0025] Use fluid models to characterize the effects of pressure and temperature changes on fluids, calculate the bulk modulus and density of gas-bearing formation water, and calculate the density and bulk modulus of gas-bearing oil;

[0026] The density and bulk modulus of the mixed phase fluid are calculated based on the bulk modulus and density of the gas-bearing formation water and the density and bulk modulus of the gas-bearing oil.

[0027] In a further technical solution, the bulk modulus and shear modulus of the saturated rock are calculated as follows:

[0028]

[0029] G sat =G dry

[0030] Among them, Kfl is the bulk modulus of the mixed fluid, K dry , G dry is the bulk modulus and shear modulus of the dry rock skeleton, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

[0031] A further technical solution is to obtain the seismic rock physics model of the turbidite sandstone reservoir by calculating the longitudinal wave velocity and the transverse wave velocity of the equivalent fluid saturated rock after the rock physical fluid is replaced according to the longitudinal and transverse wave velocity formulas to obtain the seismic rock physics model of the turbidite sandstone reservoir.

[0032] In a further technical solution, the calculation formulas for the longitudinal wave velocity and the transverse wave velocity are:

[0033]

[0034]

[0035] Among them, V P and V S are the longitudinal wave velocity and shear wave velocity of fluid-saturated rock, respectively, sat is the density of fluid-saturated rock, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

[0036] In a second aspect, the present invention provides a reservoir seismic rock physics modeling system considering fluid miscibility, comprising:

[0037] A rock matrix model building module is configured to: obtain rock matrix mineral components and volume content, and given an initial rock mineral modulus, build a rock matrix model;

[0038] A rock skeleton model building module is configured to: calculate the elastic modulus of the rock skeleton using contact theory based on the rock matrix model to build a rock skeleton model;

[0039] The rock physics model building module is configured to: calculate the bulk modulus and shear modulus of the rock saturated with the miscible fluid based on the rock skeleton model, construct a rock model saturated with the miscible fluid, and finally obtain a seismic rock physics model of the turbidite sandstone reservoir.

[0040] In a third aspect, the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps in a reservoir seismic rock physics modeling method taking into account fluid miscibility as described in the first aspect.

[0041] In a fourth aspect, the present invention provides a computer 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 program, the steps in a reservoir seismic rock physics modeling method taking into account fluid miscibility as described in the first aspect are implemented.

[0042] One or more of the above technical solutions have the following beneficial effects:

[0043] The present invention considers the mixed phase situation of fluid dissolution at different temperatures and pressures based on the Batzle-Wang fluid model and adds the mixed phase fluid to the rock physics model, making the model more accurate and being able to establish the relationship between the physical property parameters of the turbidite sandstone reservoir and the seismic characteristics.

[0044] The present invention constructs a seismic rock physics model of turbidite sandstone taking into account fluid miscibility, establishes a quantitative relationship between physical property parameters (porosity, saturation), fluid gas content, and formation pressure and elastic parameters (P-wave velocity, S-wave velocity) of turbidite sandstone, provides a theoretical model for seismic response characteristic analysis and reservoir prediction of turbidite sandstone and fluid miscibility, and provides reliable technology and methods for the exploration and development of remaining oil and gas in turbidite sandstone.

[0045] The present invention models the physical model of reservoir seismic rock based on the fluid density and bulk modulus under the mixed phase condition of oil, gas and water in the actual development process. The present invention considers the fluid miscibility in the process of seismic rock physics modeling of turbidite sandstone reservoirs, calculates the changes in fluid density and bulk modulus under different gas contents, and then establishes a turbidite sandstone rock physics model that is more in line with the actual situation, making up for the shortcomings of the conventional rock physics modeling method that simply adopts the fluid uniform mixing and non-uniform mixing method. Consider that as the gas content increases, the longitudinal wave velocity and density of the saturated rock decrease, while the shear wave velocity increases. In addition, the gas content of the fluid will affect the difference in the elastic parameters of the saturated rock caused by the water saturation within the same range of variation, which is of great significance for detecting changes in underground reservoirs.

[0046] The rock physics model established by the method of the present invention can more accurately characterize the changes in physical properties of reservoir rock miscibility during gas injection and production, laying a theoretical foundation for converting reservoir elastic parameters into physical property parameters. The rock physics model can realize the conversion of seismic information into lithological information and quantify the uncertainty relationship between the two. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0048] Figure 1is a flow chart of a rock physics modeling method according to an embodiment of the present invention;

[0049] Figure 2 Schematic diagram of turbidite sandstone fluid miscibility according to an embodiment of the present invention;

[0050] Figure 3 is a comparison chart of model prediction results of a conventional rock physics modeling method in an embodiment of the present invention and a method of the present invention;

[0051] Figure 4 is a schematic diagram of the prediction error analysis of the model according to the embodiment of the present invention;

[0052] Figure 5 This is a schematic diagram of the model prediction error analysis of the conventional method. DETAILED DESCRIPTION

[0053] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0054] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0055] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0056] Embodiment 1

[0057] like Figure 1 As shown, this embodiment discloses a reservoir seismic rock physics modeling method considering fluid miscibility, the method comprising the following steps:

[0058] S1: Obtain the rock matrix mineral components and volume content, and give the initial rock mineral modulus to construct the rock matrix model;

[0059] In this embodiment, the matrix mineral components and volume content are obtained based on experimental data and logging data. The mineral content is clay and quartz, and the modulus refers to the bulk modulus and shear modulus, both of which are commonly used empirical values ​​in the laboratory.

[0060] Given the initial rock mineral modulus, the Voigt-Reuss-Hill average method is used to calculate the bulk modulus and shear modulus of the rock matrix and construct a rock matrix model. The specific process of rock matrix modeling is as follows:

[0061]

[0062] K V =V shale K shale +(1-V shale )V sand (2)

[0063]

[0064]

[0065] G V =V shale G shale +(1-V shale )G sand (5)

[0066]

[0067] Among them, K V represents the equivalent bulk modulus calculated using the Voigt upper limit; K R represents the equivalent bulk modulus calculated using the Reuss lower limit; V shale is the mud content; K ma , K sand , K shale are the bulk moduli of the rock matrix, the sandy mineral components that constitute the rock matrix, and the argillaceous mineral components; G V represents the equivalent shear modulus calculated using the Voigt upper limit; G R represents the equivalent shear modulus calculated using the Reuss lower limit; G ma , G sand , G shale They are the shear moduli of the matrix, the sandy mineral component that constitutes the rock matrix, and the muddy mineral component.

[0068] In this embodiment, the initial rock mineral modulus is set according to the laboratory's commonly used empirical value, the clay bulk modulus V shale :21GPa; shear modulus G shale : 7GPa; quartz bulk modulus V shale :38GPa; Quartz shear modulus G shale :44GPa.

[0069] S2: Based on the rock matrix model, the elastic modulus of the rock skeleton is calculated using contact theory to construct a rock skeleton model;

[0070] In this embodiment, the Hertz-Mindlin contact theory is used to calculate the elastic modulus of the rock skeleton of turbidite sandstone, and the calculation formula of the contact model skeleton modulus is:

[0071]

[0072]

[0073]

[0074] Among them, K eff and G eff are the bulk modulus and shear modulus of the dry rock skeleton, φ is the porosity, P eff is the effective pressure, C is the coordination number, generally 8 to 9, and υ is the Poisson's ratio of the granular mineral.

[0075] The contact model refers to the formula for calculating the skeleton model given by the Hertz-Mindlin contact theory. The formula for calculating the skeleton model of turbidite sandstone is this step to calculate the skeleton modulus of added pores. It is the process of rock physics modeling and lays the foundation for the subsequent addition of fluid to calculate the saturated rock modulus.

[0076] S3: Based on the rock skeleton model, the bulk modulus and shear modulus of the rock saturated with the miscible fluid are calculated, and a rock model saturated with the miscible fluid is constructed, and finally a seismic rock physics model of the turbidite sandstone reservoir is obtained. Figure 2 As shown, the left side is the fluid uniform mixing method used in conventional rock physics modeling, and the right side is a schematic diagram of turbidite sandstone fluid miscibility.

[0077] S301: The pressure of the saturated rock model of the mixed phase fluid is considered using the Batzle-Wang fluid model, taking into account the impact of pressure and temperature changes on the fluid, and calculating the bulk modulus and density of gas-bearing formation water based on the three-phase miscibility of oil, gas and water.

[0078] The calculation formula is:

[0079] Formation water density:

[0080] ρ B =ρ w +S{0.668+0.44S+10 -4 [300P-2400PS+T(80+3T-3300S-13P+47PS]}(10)

[0081] Among them, ρ wis the density of pure water, P is the pore pressure, T is the temperature, and S is the salinity.

[0082] Density of pure water:

[0083]

[0084] Formation water acoustic wave velocity:

[0085]

[0086] in,

[0087]

[0088] W 00 =1402.85W 02 =3.437*10 -3

[0089] W 10 =4.871W 12 =1.739*10 -4

[0090] W 20 =-0.04783W 22 =-2.135*10 -6

[0091] W 30 =0.00014787W 32 =-1.455*10 -8

[0092] W 40 =-2.197*10 -7 W 42 =5.23*10 -11

[0093] W 01 =1.524W 03 =-1.197*10 -5

[0094] W 11 =-0.0111W 13 =-1.628*10 -6

[0095] W 21 =2.747*10 -4 W 23 =1.237*10 -10

[0096] W 31 =-6.503*10 -7W 33 =1.327*10 -10

[0097] W 41 =7.987*10 -10 W 43 =-4.614*10 -13

[0098] Among them, V W Represents the velocity of pure water (affected only by temperature and pressure), W ij represents the parameter matrix (the parameter matrix is ​​a constant), i represents the variable from 0 to 4, j represents the variable from 0 to 3, T i represents the i-th temperature, P j represents the jth pressure.

[0099] Gas dissolves in formation water, mainly causing the speed of its sound waves to change. The speed of formation water under different gas contents is:

[0100]

[0101] Among them, V b represents the formation water velocity, R GW It represents the gas-water ratio, that is, the amount of gas dissolved in formation water.

[0102] The maximum amount of gas dissolved in formation water:

[0103]

[0104] In actual situations, the maximum solubility is multiplied by the gas content of the formation water to express the various gas-bearing formation waters with different dissolved gases:

[0105]

[0106] Among them, C f is the gas content of formation water, which is a constant between 0 and 1. As for the density of formation water, there are few experimental data, but most people believe that the density has almost nothing to do with the content of dissolved gas.

[0107] The bulk modulus of gas-bearing formation water is expressed as:

[0108] K w =V b *V b * b (17)

[0109] Among them, V b represents the formation water velocity, ρ b Indicates the density of gas-bearing formation water. The density of gas-bearing formation water is not much different from that of pure water, so it is considered that the density of gas-bearing formation water is ρb Equal to the density of pure water ρ w .

[0110] The concept of miscibility is that gas dissolves in formation water and oil. This is a physical phenomenon that exists in the actual development process. Its modulus is calculated by using the Batzle-Wang fluid model under different temperature and pressure conditions. The following S303 is the calculation process.

[0111] S302: Calculate the density and bulk modulus of gas-containing petroleum (live oil). Density is a function related to pressure and temperature, and the formula is:

[0112] ρ=ρ P / [0.972+3.81*10 -4 (T+17.78) 1.175 ] (18)

[0113] Among them, ρ P is the density at fixed pressure.

[0114] The density at fixed pressure is expressed as:

[0115] ρ P =ρ0+(0.00277P-1.71*10 -7 P 3 )(ρ0-1.15) 2 +3.49*10 -4 P (19)

[0116] The speed is expressed as:

[0117]

[0118] Among them, ρ0 is the density of oil, T is the temperature, and P is the pressure.

[0119] The definition of oil with gas dissolved in it is active oil. The amount of gas dissolved in oil is greatly affected by pressure and temperature. GO The ratio of the volume of gas released to the volume of remaining crude oil under standard atmospheric pressure and 15.6°C temperature conditions.

[0120] Maximum amount of gas that can be dissolved in crude oil:

[0121]

[0122]

[0123] Among them, C f is the gas content of oil, which is a constant between 0 and 1. Density of gas-containing oil:

[0124] ρG =(ρ0+0.0012G*R GO ) / B0 (23)

[0125] B0=0.972+0.00038[2.4R GO (G / ρ0) (1 / 2) +T+1.78] 1.175 (twenty four)

[0126] The velocity of live oil is calculated using the quasi-density:

[0127]

[0128] V P =2096(ρ′ / (2.6-ρ′)) 1 / 2 -3.7T+4.64P+0.0115[4.12(1.08 / ρ′-1) 1 / 2 -1]TP (26)

[0129] The bulk modulus of live oil is expressed as:

[0130] K O =V P *V P *ρ G (27)

[0131] Among them, ρ G Expressed as the density of live oil.

[0132] S303: Calculate the density and bulk modulus of the mixed phase fluid based on the bulk modulus and density of the gas-bearing formation water and the density and bulk modulus of the gas-bearing oil.

[0133] Based on the density of gas-bearing formation water and gas-bearing oil, the respective bulk moduli, that is, the bulk modulus of the fluid, are calculated, and then the modulus of the saturated rock is calculated.

[0134] In this embodiment, the calculation formulas for the overall density and bulk modulus of the mixed phase fluid are as follows:

[0135] The density of the mixed fluid is:

[0136] ρ fl =S w *ρ w +S o *ρ o +S g *ρ g (28)

[0137] Among them, S w is the reservoir water saturation, S g is the gas saturation of the reservoir, S ois the oil saturation of the reservoir. These three are reservoir physical parameters and are variable inputs of the rock physics model. w is the density of gas-bearing formation water, ρ o is the density of live oil, ρ g is the gas density, which is approximately 0 and can be ignored.

[0138] The bulk modulus of the mixed fluid is an inhomogeneous mixture:

[0139] K fl =S w *K w +S o *K o +S g *K g (29)

[0140] Among them, K w is the bulk modulus of gas-bearing formation water, K o is the bulk modulus of live oil, K g is the gas bulk modulus, which is approximately 0 and can be ignored;

[0141] S304: The bulk modulus and shear modulus of saturated rock are calculated using the Gassman equation, and the P-wave velocity and S-wave velocity of equivalent fluid-saturated rock after the rock physical fluid is replaced are calculated based on the P-wave velocity and S-wave velocity formulas to obtain a seismic rock physics model of the turbidite sandstone reservoir.

[0142] In this example, the Gassmann equation is used to calculate the bulk modulus and shear modulus of saturated rock:

[0143]

[0144] G sat =G dry (31)

[0145] Among them, K fl is the bulk modulus of the mixed fluid, K dry , G dry is the bulk modulus and shear modulus of the dry rock skeleton, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

[0146] In the embodiment, the longitudinal wave velocity and the shear wave velocity of the equivalent fluid saturated rock after the petrophysical fluid is replaced are calculated according to the longitudinal and shear wave velocity formulas:

[0147]

[0148]

[0149] Among them, V P and V S are the longitudinal wave velocity and shear wave velocity of fluid-saturated rock, respectively, sat is the density of fluid-saturated rock, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

[0150] The present invention obtains the equivalent mineral modulus of mineral particles through S1, obtains the rock skeleton modulus considering the addition of pores through S2, obtains the elastic modulus of the mixed fluid through S3, and then obtains the modulus of the saturated rock after adding the fluid, and calculates the longitudinal and transverse wave velocities and density of the reservoir based on this.

[0151] like Figure 3 As shown in the figure, the prediction results of the conventional rock physics modeling method in the mixed phase section, the prediction results of the model of the method of the present invention, and the actual curve of the gas injection well (partial section) are given. It can be seen that the model of the present invention has a good fit for the elastic parameters of the reservoir after gas injection and has a high accuracy. Figure 4 , Figure 5 As shown, the P-wave and S-wave velocities predicted by the rock physics model established using this method conform to the normal distribution, and most of the P-wave velocity errors are less than 0.1, which shows that the model has high accuracy.

[0152] The rock physics model of the present invention is established based on a step-by-step formula, and can use the known physical parameters of the reservoir (such as temperature, porosity, shale content, water saturation, pressure) information to calculate the underground elastic parameters (such as P-wave velocity, density and various elastic parameters). The seismic rock physics model is a bridge connecting the seismic elastic parameters and the reservoir physical parameters, laying a theoretical foundation for converting the elastic parameters into physical parameters. The seismic rock physics model can realize the transformation of seismic information into lithological information, and can also quantify the uncertainty relationship between them.

[0153] Embodiment 2

[0154] This embodiment discloses a reservoir seismic rock physics modeling system considering fluid miscibility, including:

[0155] A rock matrix model building module is configured to: obtain rock matrix mineral components and volume content, and given an initial rock mineral modulus, build a rock matrix model;

[0156] A rock skeleton model building module is configured to: calculate the elastic modulus of the rock skeleton using contact theory based on the rock matrix model to build a rock skeleton model;

[0157] The rock physics model building module is configured to: calculate the bulk modulus and shear modulus of the rock saturated with the miscible fluid based on the rock skeleton model, construct a rock model saturated with the miscible fluid, and finally obtain a seismic rock physics model of the turbidite sandstone reservoir.

[0158] Embodiment 3

[0159] The purpose of this embodiment is to provide a computing device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method of embodiment 1 when executing the program.

[0160] Embodiment 4

[0161] The purpose of this embodiment is to provide a computer-readable storage medium, a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the steps of the method of embodiment 1 are performed.

[0162] The steps involved in the apparatus of the above embodiments 3 and 4 correspond to the method embodiment 1, and the specific implementation method can refer to the relevant description part of embodiment 1. The term "computer-readable storage medium" should be understood as a single medium or multiple media including one or more instruction sets; it should also be understood to include any medium that can store, encode or carry an instruction set for execution by a processor and enable the processor to execute any method in the present invention.

[0163] Those skilled in the art should understand that the modules or steps of the present invention described above can be implemented by a general-purpose computer device, or alternatively, they can be implemented by a program code executable by a computing device, so that they can be stored in a storage device and executed by the computing device, or they can be made into individual integrated circuit modules, or multiple modules or steps therein can be made into a single integrated circuit module for implementation. The present invention is not limited to any specific combination of hardware and software.

[0164] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

[0165] Although the above describes the specific implementation mode of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A reservoir seismic rock physics modeling method considering fluid miscibility, characterized in that: include: Obtain the rock matrix mineral components and volume content, and given the initial rock mineral modulus, construct the rock matrix model; Based on the rock matrix model, the elastic modulus of the rock skeleton is calculated using contact theory to construct a rock skeleton model; Based on the rock skeleton model, the bulk modulus and shear modulus of the rock saturated with the miscible fluid are calculated, a rock model saturated with the miscible fluid is constructed, and finally a seismic rock physics model of the turbidite sandstone reservoir is obtained.

2. A reservoir seismic rock physics modeling method considering fluid miscibility as claimed in claim 1, characterized in that: The specific process of the rock matrix model is as follows: K V =V shale K shale +(1-V shale )V sand G V =V shale G shale +(1-V shale )G sand Among them, K V represents the equivalent bulk modulus; K R Represents the equivalent bulk modulus; V shale is the mud content; K ma , K sand , K shale are the bulk moduli of the rock matrix, the sandy mineral components that constitute the rock matrix, and the argillaceous mineral components; G V Represents the equivalent shear modulus; G R Represents the equivalent shear modulus; G ma , G sand , G shale They are the shear moduli of the matrix, the sandy mineral component that constitutes the rock matrix, and the muddy mineral component.

3. A reservoir seismic rock physics modeling method considering fluid miscibility as claimed in claim 1, characterized in that: The elastic modulus of the rock skeleton is calculated as follows: Among them, K eff and G eff are the bulk modulus and shear modulus of the dry rock skeleton, φ is the porosity, P eff is the effective pressure, C is the coordination number, and υ is the Poisson's ratio of the granular mineral.

4. A reservoir seismic rock physics modeling method considering fluid miscibility as claimed in claim 1, characterized in that: The bulk modulus and shear modulus of the rock saturated with the miscible fluid are calculated as follows: Use fluid models to characterize the effects of pressure and temperature changes on fluids, calculate the bulk modulus and density of gas-bearing formation water, and calculate the density and bulk modulus of gas-bearing oil; The density and bulk modulus of the mixed phase fluid are calculated based on the bulk modulus and density of the gas-bearing formation water and the density and bulk modulus of the gas-bearing oil.

5. A reservoir seismic rock physics modeling method considering fluid miscibility as claimed in claim 4, characterized in that: The bulk modulus and shear modulus calculation formula of the saturated rock are: G sat =G dry Among them, K fl is the bulk modulus of the mixed fluid, K dry , G dry is the bulk modulus and shear modulus of the dry rock skeleton, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

6. A reservoir seismic rock physics modeling method considering fluid miscibility according to claim 1, characterized in that: The seismic rock physics model of the turbidite sandstone reservoir is obtained by calculating the longitudinal wave velocity and the transverse wave velocity of the equivalent fluid saturated rock after the rock physics fluid is replaced according to the longitudinal and transverse wave velocity formulas to obtain the seismic rock physics model of the turbidite sandstone reservoir.

7. A reservoir seismic rock physics modeling method considering fluid miscibility as claimed in claim 6, characterized in that: The calculation formulas for the longitudinal wave velocity and the shear wave velocity are: Among them, V P and V S are the longitudinal wave velocity and shear wave velocity of fluid-saturated rock, respectively, sat is the density of fluid-saturated rock, K sat , G sat are the bulk modulus and shear modulus of fluid-saturated rock.

8. A reservoir seismic rock physics modeling system considering fluid miscibility, characterized in that: include: A rock matrix model building module is configured to: obtain rock matrix mineral components and volume content, and given an initial rock mineral modulus, build a rock matrix model; A rock skeleton model building module is configured to: calculate the elastic modulus of the rock skeleton using contact theory based on the rock matrix model to build a rock skeleton model; The rock physics model building module is configured to: calculate the bulk modulus and shear modulus of the rock saturated with the miscible fluid based on the rock skeleton model, construct a rock model saturated with the miscible fluid, and finally obtain a seismic rock physics model of the turbidite sandstone reservoir.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps in a reservoir seismic rock physics modeling method considering fluid miscibility as described in any one of claims 1 to 7 are implemented.

10. A computer 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 program, the steps in a reservoir seismic rock physics modeling method considering fluid miscibility as described in any one of claims 1-7 are implemented.

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