Method and apparatus for determining crude oil gas hydrocarbon concentration

Abstract

The embodiment of the present application provides a kind of crude oil oil gas hydrocarbon concentration determination method and device, the method is applied to underground water seal oil depot, method includes: obtaining the component concentration of each component of crude oil, wherein component concentration is the molar fraction of each component of crude oil;The concentration distribution of hydrocarbon component at interface under gas-liquid equilibrium state in cavern is calculated based on each component concentration;The physical model of underground water seal oil depot is established, and grid division is carried out;Corresponding oil gas flow model is generated based on concentration distribution relationship and grid division;The boundary condition at oil gas outlet is determined, and the oil gas flow model is solved based on outlet boundary condition, and the concentration of hydrocarbon component at oil gas outlet is obtained.The method obtains the volatile concentration of hydrocarbon gas at gas-liquid interface and inside by volatile model.Again through flow model, the concentration distribution of hydrocarbon gas inside cavern is calculated, and finally the hydrocarbon gas concentration at gas outlet is obtained.

Description

Technical Field

[0001] This invention relates to the field of petrochemical technology, and in particular to a method and apparatus for determining the concentration of hydrocarbons in crude oil and gas. Background Technology

[0002] During oil and gas storage and transportation, in the case of underground water-sealed oil depots, crude oil will volatilize hydrocarbon components within the depot's cavern. When oil is introduced into the cavern, due to the reduced gas phase space, oil and gas will overflow outside the cavern through the gas outlet, where hydrocarbon components are recovered by an oil and gas recovery device and discharged only after meeting emission standards. Current calculations of hydrocarbon concentration in oil depots often involve directly performing phase equilibrium calculations on the crude oil to obtain the concentration of volatilized oil and gas, and then calculating the volume of discharged oil and gas based on the volume of crude oil entering and leaving the depot.

[0003] However, currently there is a lack of accurate methods for calculating the concentration of hydrocarbon components in oil and gas; most methods rely on direct phase equilibrium estimations. Oil and gas components stratify in the gas phase due to density differences, and the introduction of nitrogen during oil extraction disrupts this stratification, further complicating the distribution of light and heavy components. Because the impact of nitrogen flow within the storage cavern on oil and gas concentration is not considered, conservative values ​​are often used, leading to significant deviations between the designed and actual oil and gas concentration values ​​of oil and gas recovery units. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a method and apparatus for determining the concentration of hydrocarbon components in crude oil and gas, so as to solve the technical problem that the design value of the concentration of oil and gas in the oil and gas recovery device deviates greatly from the actual value due to the lack of a relatively accurate calculation method for the concentration of hydrocarbon components in oil and gas, and the estimation of oil and gas concentration by directly performing phase equilibrium.

[0005] In a first aspect, embodiments of the present invention provide a method for determining the concentration of hydrocarbons in crude oil and gas. This method is applied to an underground water-sealed oil depot. The method includes: obtaining the component concentrations of each component of crude oil, wherein the component concentration is the mole fraction of each component in the crude oil; calculating the concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium in the underground depot based on the concentrations of each component; establishing a physical model of the underground water-sealed oil depot and performing mesh generation; generating a corresponding oil and gas flow model based on the concentration distribution relationship and mesh generation; determining the boundary conditions at the oil and gas outlet; and solving the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet.

[0006] Furthermore, the calculation of hydrocarbon gas composition under gas-liquid equilibrium state in the oil depot based on component concentration includes: determining the PR equation of state for hydrocarbon gases in the oil-gas gas phase space based on component concentration; solving the equation of state to calculate the concentration distribution of hydrocarbon gases.

[0007] Furthermore, a physical model of the underground water-sealed oil depot is established, including: taking a longitudinal section of the physical model of the underground water-sealed oil depot; dividing the longitudinal section and establishing a quadrilateral, triangular, or hybrid grid of the longitudinal section; determining the spatial coordinates of each grid as the corresponding spatial coordinates of the underground water-sealed oil depot to generate the physical model of the underground water-sealed oil depot.

[0008] Furthermore, the physical model is either a two-dimensional model or a three-dimensional model, wherein the mesh of the three-dimensional model is a hexahedron or a tetrahedron.

[0009] Furthermore, based on the concentration distribution and spatial grid division, a corresponding oil and gas flow model is generated, including: obtaining the gas flow velocity of the corresponding hydrocarbon gas components within the spatial grid; and substituting the relationship between the gas flow velocity and the concentration distribution at the gas-liquid interface and the corresponding spatial coordinates into a preset equation to establish the oil and gas flow model.

[0010] Furthermore, the method also includes: determining the boundary conditions at the oil and gas inlet and outlet; wherein the boundary conditions are gas pressure, gas flow velocity and inlet and outlet conditions; and selecting the corresponding preset equation based on the boundary conditions.

[0011] Furthermore, in the method, the gasification rate of crude oil is 1.0 × 10⁻⁶. -8 ~0.01.

[0012] Furthermore, the internal temperature and oil / gas temperature of the underground water-sealed oil reservoir range from 15 to 50°C.

[0013] Furthermore, the operating pressure range of the underground water-sealed oil depot is 0–100 kPa.

[0014] Secondly, embodiments of the present invention provide a crude oil hydrocarbon concentration determination device, which is used to execute the method in claims 1-9 above. The device includes: a component acquisition module, used to acquire the component concentration of each component of crude oil, wherein the component concentration is the mole fraction of each component of crude oil; a concentration calculation module, used to calculate the concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium state in the underground storage based on the concentration of each component; a model establishment module, used to establish a physical model of the underground water-sealed oil storage and perform mesh generation; a model generation module, used to generate a corresponding oil and gas flow model based on the concentration distribution relationship at the interface and the mesh generation; and a condition determination module, used to determine the boundary conditions at the oil and gas outlet, and solve the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet.

[0015] The embodiments of the present invention bring the following beneficial effects:

[0016] This invention provides a method for determining the concentration of hydrocarbons in crude oil and gas. The method is applied to underground water-sealed oil depots and includes: obtaining the component concentrations of each component of the crude oil, where the component concentration is the mole fraction of each component; calculating the concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium conditions within the depot based on the component concentrations; establishing a physical model of the underground water-sealed oil depot and performing mesh generation; generating a corresponding oil and gas flow model based on the concentration distribution relationship at the interface and the mesh generation; determining the boundary conditions at the oil and gas outlet; and solving the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet. This method can be applied to the calculation of oil and gas volatilization concentrations in underground water-sealed depots of any structure and shape. First, the volatilization model is used to obtain the hydrocarbon gas volatilization concentrations at the gas-liquid interface and inside the depot. Then, the flow model is used to calculate the hydrocarbon gas concentration distribution inside the depot, finally obtaining the hydrocarbon gas concentration at the gas outlet.

[0017] Other features and advantages of this disclosure will be set forth in the following description, or some features and advantages may be inferred from the description or determined without doubt, or may be learned by practicing the techniques described above.

[0018] To make the above-mentioned objects, features and advantages of this disclosure more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 A flowchart of a method for determining the concentration of hydrocarbons in crude oil and gas provided in an embodiment of the present invention;

[0021] Figure 2 A flowchart of another method for determining the concentration of hydrocarbons in crude oil and gas provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of a crude oil and gas hydrocarbon concentration determination device provided in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Currently, underground water-sealed oil depots are often used in oil storage and transportation. Within these depots, hydrocarbon components volatilize from the oil and gas inside the cavern. When oil is introduced into the cavern, the reduced gas phase space causes hydrocarbons to overflow through the gas outlet, where they are recovered by an oil and gas recovery unit before being discharged in compliance with standards. Current calculations of hydrocarbon concentration in oil depots often involve directly performing phase equilibrium calculations on the crude oil to obtain the concentration of volatilized oil and gas, and then using the volume of crude oil entering and leaving the depot to determine the volume of discharged oil and gas. However, there is a lack of accurate methods for calculating the concentration of hydrocarbon components in the oil and gas; most calculations rely on estimations based on direct phase equilibrium. Oil and gas components stratify in the gas phase due to differences in density, and the introduction of nitrogen during oil discharge disrupts this stratification, further dispersing the distribution of light and heavy components. Because the impact of nitrogen flow within the cavern on the oil and gas concentration is not considered, conservative values ​​are often used, leading to significant deviations between the actual processing capacity of the oil and gas recovery unit and the actual concentration. Simultaneously, sampling analysis is also used to obtain oil and gas concentrations. This method is relatively accurate, but because the gas concentration inside the cavern is dynamically changing, it is difficult to adjust in a timely manner. Moreover, if the sampling method is used to obtain the true concentration, improper sampling procedures can lead to significant deviations between the measurement results and the actual values.

[0026] Based on this, the method and apparatus for determining the concentration of hydrocarbons in crude oil and gas provided in this embodiment of the invention can take into account the influence of the properties of crude oil and correct for the flow of gas in the cavern, resulting in more accurate calculation results, a simple solution model, clear steps, and versatility.

[0027] To facilitate understanding of this embodiment, a method for determining the concentration of hydrocarbons in crude oil and gas disclosed in this embodiment of the invention will first be described in detail.

[0028] For underground water-sealed caverns, the liquid level drops and the gas phase space expands during crude oil export. To prevent a vacuum caused by oil extraction, nitrogen needs to be added to the gas phase space when the pressure is low to maintain relative pressure balance. When oil is introduced, the gas phase space decreases and the pressure increases, releasing gas to the outside of the cavern. Due to the evaporation of hydrocarbon components in the crude oil, the gas phase space becomes filled with a mixture of nitrogen and hydrocarbon gases. According to environmental protection requirements, this gas cannot be directly released into the atmosphere and must be treated in an oil and gas recovery unit before being released into the atmosphere.

[0029] When the cavern is filled with crude oil, the crude oil will volatilize at the gas-liquid interface, and the hydrocarbon components will mix with the nitrogen gas already present in the cavern and reach an equilibrium state. Due to the density differences between the different components, the distribution of the hydrocarbon components is not completely uniform, but rather a process of diffusion from the liquid phase to the gas phase. Near the liquid surface, there are more heavy components, while at higher points inside the cavern, there are more light components.

[0030] During oil extraction, the nitrogen supply line is opened to inject nitrogen into the cavern, forming a mixture with the existing hydrocarbon components. Because the nitrogen inlet is located in the upper part of the cavern, convection occurs in the gas phase space, causing localized concentration changes. These concentration changes directly affect the concentration of the gas discharged from the cavern, thus influencing the concentration of oil and gas processed by subsequent processes (such as oil and gas recovery facilities). However, there is currently a lack of analysis on these concentration changes; methods rely on experience or sample analysis results, inevitably leading to underestimation or overestimation of the scale of oil and gas processing. Therefore, accurate analysis of oil and gas concentrations is crucial for environmental protection.

[0031] See Figure 1 The flowchart shown illustrates a method for determining the concentration of hydrocarbons in crude oil and gas. This application provides a method for determining the concentration of hydrocarbons in crude oil and gas, applicable to underground water-sealed oil depots, such as... Figure 1 As shown, the method includes the following steps:

[0032] Step S101: Obtain the component concentration of each component of crude oil, wherein the component concentration is the mole fraction of each component of crude oil;

[0033] Specifically, in practical applications, component measurements can be performed based on a displayed crude oil sample. The following table shows the component concentrations of various components in a crude oil sample as an example:

[0034]

[0035]

[0036] In practical applications, although the crude oil mentioned above does not contain H2S, the method provided in this application embodiment is still applicable to crude oil containing H2S, with the corresponding H2S content in the oil and gas ranging from 10 to 2500 ppm. Therefore, this invention embodiment does not specifically limit the specific components contained in the crude oil.

[0037] Step S102: Calculate the concentration distribution of hydrocarbon components in the cavern under gas-liquid equilibrium state based on the concentration of each component.

[0038] Specifically, the PR equation can be used to calculate the concentration distribution of each hydrocarbon gas in the gas phase space.

[0039] The PR equation can be found in the following formula:

[0040]

[0041] Where P is the working fluid pressure of the corresponding crude oil component; R is the gas constant, 8.314 J / (mol·K); T is the working fluid temperature of the corresponding crude oil component; and V is the specific volume of the working fluid of the corresponding crude oil component, in m³. 3 / mol; b and c are equation parameters.

[0042] Specifically, the calculation of each parameter in the above equation can be expressed as follows:

[0043] a = 0.45724R 2 T c 2 / P c ;

[0044] b = 0.0778RT c / P c ;

[0045] c=[1+f(ω)(1-Tr 0.5 )] 2 ;

[0046] f(ω)=0.37464+1.54226ω-0.26992ω 2 ;

[0047] Tr = T / Tc.

[0048] Where Tc is the critical temperature; Pc is the critical pressure; ω is the eccentricity factor; and Tr is the relative temperature.

[0049] Specifically, the specific volume of each component of crude oil can be solved using the PR equation of state described above. In practice, two results may be obtained. If one real root and two imaginary roots are obtained, then the real root of this equation is the specific volume.

[0050] If three real roots are obtained, since the working fluid is in a state of gas-liquid equilibrium, the smallest real root is the specific volume of the saturated liquid, and the largest real root is the specific volume of the saturated gas.

[0051] In practical applications, the gasification rate of crude oil can be taken as 0 to 0.1. Preferably, the gasification rate can be taken as 10 × 10⁻⁶. -8 ~0.01.

[0052] Corresponding to the component concentrations of the crude oil components illustrated above, the gas composition under gas-liquid equilibrium can be calculated using the PR equation, as shown in the table below:

[0053]

[0054]

[0055] Step S103: Establish a physical model of the underground water-sealed oil reservoir and perform mesh generation;

[0056] Specifically, Gambit software can be used to establish a physical model of the aforementioned underground water-sealed oil reservoir. The physical model can be a two-dimensional model or a three-dimensional model. When a two-dimensional model is required, a triangular or quadrilateral mesh of the aforementioned longitudinal section can be established. When a three-dimensional model is required, a tetrahedral or hexahedral mesh of the aforementioned model can be established.

[0057] Step S104: Generate the corresponding oil and gas flow model based on the concentration distribution relationship at the interface and the mesh division;

[0058] Specifically, the gas flow model described above can be established using FLUENT software based on the continuity equation and the momentum conservation equation (NS equation):

[0059] The gas flow model under the above physical model can be expressed as:

[0060]

[0061] Where u represents the velocity component of the gas flow in the x-axis direction at time t in the above physical model; v represents the velocity component of the gas flow in the y-axis direction at time t in the above physical model; and w represents the velocity component of the gas flow in the z-axis direction at time t in the above physical model.

[0062] Furthermore, since the gas viscosity is low under gas flow conditions, viscosity can be disregarded, thus yielding the Euler equation corresponding to the above gas flow model:

[0063]

[0064]

[0065]

[0066] Where u represents the velocity component of the gas flow in the x-axis direction at time t in the above physical model; v represents the velocity component of the gas flow in the y-axis direction at time t in the above physical model; w represents the velocity component of the gas flow in the z-axis direction at time t in the above physical model; F x F is the external force on a unit volume of gas in the x-axis direction at time t. y F is the external force received by a unit volume of gas in the y-axis direction at time t. z Let be the external force received by a unit volume of gas in the z-axis direction at time t.

[0067] Step S105: Determine the boundary conditions at the oil and gas outlet, and solve the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas inlet and outlet.

[0068] In practical applications, the concentrations of hydrocarbon components at the inlet and outlet can be determined by using the coordinates of the inlet and outlet of the oil and gas flow model and the Euler equations corresponding to the gas flow models at each location.

[0069] This invention provides a method for determining the concentration of hydrocarbons in crude oil and gas. The method is applied to underground water-sealed oil depots and includes: obtaining the component concentrations of each component in the crude oil, where the component concentration is the mole fraction of each component; calculating the concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium conditions within the depot based on the component concentrations; establishing a physical model of the underground water-sealed oil depot and performing mesh generation; generating a corresponding oil and gas flow model based on the concentration distribution relationship and mesh generation; determining the boundary conditions at the oil and gas outlet; and solving the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet. This method can be applied to the calculation of oil and gas volatilization concentrations in underground water-sealed depots of any structure and shape. First, the volatilization concentration of hydrocarbon gases at the gas-liquid interface is obtained using the volatilization model. Then, the flow of nitrogen and hydrocarbon gases inside the depot is calculated using the flow model, ultimately obtaining the hydrocarbon gas concentration at the gas outlet.

[0070] Based on the above embodiments, this invention also provides another method for determining the concentration of hydrocarbons in crude oil and gas. Specifically, this method is implemented based on the above embodiments, see [link to relevant documentation]. Figure 2 The flowchart shown below illustrates another method for determining the concentration of hydrocarbons in crude oil and gas, which includes the following steps:

[0071] Step S201: Obtain the component concentration of each component of crude oil, wherein the component concentration is the mole fraction of each component of crude oil;

[0072] Step S202: Based on the component concentration, determine the PR equation of state for hydrocarbon gases in the oil and gas gas phase space;

[0073] Step S203: Solve the equation of state to calculate the concentration distribution of the hydrocarbon gas;

[0074] Step S204: Take a longitudinal section of the physical model of the underground water-sealed oil reservoir;

[0075] Step S205: Divide the longitudinal section and establish a quadrilateral, triangular, or mixed-form mesh for the longitudinal section;

[0076] Step S206: Determine the spatial coordinates of each quadrilateral grid as the spatial coordinates corresponding to the underground water-sealed oil reservoir to generate the physical model of the underground water-sealed oil reservoir;

[0077] In practical applications, the above physical model can be a two-dimensional model or a three-dimensional model. When a two-dimensional model is required, a quadrilateral mesh of the above longitudinal section can be created. When a three-dimensional model is required, a hexahedral or tetrahedral mesh of the above model can be created.

[0078] Step S207: Obtain the gas flow velocity of the corresponding hydrocarbon gas component within the spatial grid;

[0079] Step S208: Substitute the gas flow velocity, the concentration distribution, and the corresponding spatial coordinates into a preset equation to establish the oil and gas flow model.

[0080] The boundary conditions at the oil and gas outlet are determined, and the oil and gas flow model is solved based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet.

[0081] In practical applications, the boundary conditions at the oil and gas inlet and outlet can be determined; wherein, the boundary conditions are gas pressure, gas flow velocity and inlet and outlet conditions (e.g., pressure inlet, velocity inlet, pressure outlet, etc.);

[0082] Based on the aforementioned boundary conditions, a corresponding preset equation is selected. The concentrations of each hydrocarbon component at the oil and gas outlet are then obtained by solving the corresponding preset equation.

[0083] In practical applications, the internal temperature and oil and gas temperature of the aforementioned underground water-sealed oil depot range from 15 to 50°C.

[0084] The operating pressure range of the underground water-sealed oil depot is 0–100 kPa.

[0085] It should be noted that in the embodiments of the present invention, the oil and gas components and hydrocarbon components refer to the same concept, and the liquid surface and oil and gas interface refer to the same concept.

[0086] Corresponding to the above method embodiments, this invention provides a crude oil and gas hydrocarbon concentration determination device, such as... Figure 3 The diagram shows a structural schematic of a crude oil and gas hydrocarbon concentration determination device. This device is used to perform any of the methods described above. The device includes:

[0087] The component acquisition module 301 is used to acquire the component concentration of each component of crude oil, wherein the component concentration is the mole fraction of each component of crude oil;

[0088] The concentration calculation module 302 is used to calculate the concentration distribution of hydrocarbon components in the cavern under gas-liquid equilibrium state based on the concentration of each component.

[0089] The model building module 303 is used to build a physical model of the underground water-sealed oil reservoir and perform mesh generation;

[0090] Model generation module 304 is used to generate a corresponding oil and gas flow model based on the concentration distribution relationship and grid division;

[0091] The condition determination module 305 is used to determine the boundary conditions at the oil and gas outlet, and solve the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet.

[0092] The data manipulation device provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned data manipulation method embodiment. For the sake of brevity, any parts of the data manipulation device embodiment not mentioned can be referred to the corresponding content in the aforementioned data manipulation method embodiment.

[0093] The crude oil and gas hydrocarbon concentration determination device provided in this embodiment of the invention has the same technical features as the crude oil and gas hydrocarbon concentration determination method provided in the above embodiments, so it can also solve the same technical problems and achieve the same technical effects.

[0094] This invention also provides an electronic device, such as... Figure 4 The diagram shows the structure of the electronic device, which includes a processor 41 and a memory 42. The memory 42 stores machine-executable instructions that can be executed by the processor 41. The processor 41 executes the machine-executable instructions to implement the above-mentioned method for determining the concentration of hydrocarbons in crude oil and gas.

[0095] exist Figure 4 In the illustrated embodiment, the electronic device further includes a bus 43 and a communication interface 44, wherein the processor 41, the communication interface 44, and the memory 42 are connected via the bus.

[0096] The memory 42 may include high-speed random access memory (RAM) or non-volatile memory, such as at least one disk storage device. Communication between this system network element and at least one other network element is achieved through at least one communication interface 44 (which can be wired or wireless), such as the Internet, wide area network, local area network, metropolitan area network, etc. The bus can be an ISA bus, PCI bus, or EISA bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 4 The symbol is represented by a single double-headed arrow, but this does not mean that there is only one bus or one type of bus.

[0097] Processor 41 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 41 or by software instructions. Processor 41 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this invention. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in the memory. The processor 41 reads the information in the memory 42 and, in conjunction with its hardware, completes the steps of the crude oil and gas hydrocarbon concentration determination method of the aforementioned embodiment.

[0098] This invention also provides a machine-readable storage medium storing machine-executable instructions. When these machine-executable instructions are called and executed by a processor, they cause the processor to implement the above-described method for determining the concentration of hydrocarbons in crude oil and gas. For specific implementation details, please refer to the foregoing method embodiments, which will not be repeated here.

[0099] The computer program products of the crude oil and gas hydrocarbon concentration determination method, crude oil and gas hydrocarbon concentration determination device and electronic device provided in the embodiments of the present invention include a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the crude oil and gas hydrocarbon concentration determination method described in the preceding method embodiments. For specific implementation, please refer to the method embodiments, which will not be repeated here.

[0100] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0101] Furthermore, in the description of the embodiments of the present invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention based on the specific circumstances.

[0102] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0103] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit it. The scope of protection of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for determining the concentration of hydrocarbons in crude oil and gas, characterized in that, The method is applied to underground water-sealed oil depots, and the method includes: The component concentrations of each component of crude oil are obtained, wherein the component concentration is the mole fraction of each component of crude oil; The concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium in the cavern was calculated based on the concentration of each component. A physical model of the underground water-sealed oil reservoir was established, and a mesh was generated. Based on the concentration distribution and grid division, a corresponding oil and gas flow model is generated; The boundary conditions at the oil and gas outlet are determined, and the oil and gas flow model is solved based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet. Establish a physical model of the underground water-sealed oil reservoir, including: A longitudinal section of the physical model of the underground water-sealed oil reservoir is taken; The longitudinal section is divided to create a grid of quadrilaterals, triangles, or a combination of both. The spatial coordinates of each grid are determined as the spatial coordinates corresponding to the underground water-sealed oil reservoir to generate the physical model of the underground water-sealed oil reservoir; Based on the concentration distribution and spatial grid division, a corresponding oil and gas flow model is generated, including: Obtain the gas flow velocity of the corresponding hydrocarbon gas component within the spatial grid; The gas flow velocity, concentration distribution, and corresponding spatial coordinates are substituted into a preset equation to establish the oil and gas flow model.

2. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, The concentration distribution of hydrocarbon components at the interface under gas-liquid equilibrium in the cavern, calculated based on the concentrations of each component, includes: Based on the component concentrations, the PR equation of state for hydrocarbon gases in the oil and gas gas phase space is determined. Solve the equation of state to calculate the concentration distribution of the hydrocarbon gas.

3. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, The physical model can be a two-dimensional model or a three-dimensional model.

4. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, The method further includes: Determine the boundary conditions at the oil and gas inlet and outlet; wherein, the boundary conditions are gas pressure, gas flow velocity, and inlet and outlet conditions; Select the corresponding preset equation based on the boundary conditions.

5. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, In the method, the gasification rate of the crude oil is 1.0 × 10⁻⁶. -8 ~0.

01.

6. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, The internal temperature and oil / gas temperature of the underground water-sealed oil reservoir range from 15 to 50°C.

7. The method for determining the concentration of hydrocarbons in crude oil and gas according to claim 1, characterized in that, The operating pressure range of the underground water-sealed oil depot is 0~100kPa (gauge pressure).

8. A device for determining the concentration of hydrocarbons in crude oil and gas, characterized in that, The apparatus is used to perform the method of any one of claims 1-7, and the apparatus comprises: A component acquisition module is used to acquire the component concentration of each component of crude oil, wherein the component concentration is the mole fraction of each component of crude oil; The concentration calculation module is used to calculate the concentration distribution of hydrocarbon components at the gas-liquid interface under gas-liquid equilibrium state in the cave based on the concentration of each component. The model building module is used to build a physical model of the underground water-sealed oil reservoir and perform mesh generation; The model generation module is used to generate a corresponding oil and gas flow model based on the concentration distribution relationship and grid division. The condition determination module is used to determine the boundary conditions at the oil and gas outlet, and solve the oil and gas flow model based on the outlet boundary conditions to obtain the concentration of hydrocarbon components at the oil and gas outlet.

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