Oil and gas reservoir density parameter inversion method and device, electronic equipment and storage medium

Abstract

The invention discloses an oil and gas reservoir density parameter inversion method and device, electronic equipment and a storage medium, and the method comprises the steps: selecting near-angle and medium-angle superposed seismic data, carrying out the two-parameter inversion based on two Fatti approximation formulas, and obtaining the impedance of longitudinal and transverse waves; performing three-parameter forward modeling on the angle, the longitudinal and transverse wave impedance and the density initial model of the far-angle seismic data by using a Fatti three-term approximation formula to obtain forward modeling far-angle seismic data; performing conventional linear inversion by using the residual error of the far-angle original seismic data and the forward far-angle seismic data and taking the density parameter as a target to obtain a density parameter update quantity, and combining the density parameter update quantity with the density initial model to generate a density parameter inversion result; and taking the density parameter inversion result as prior information, and repeatedly executing the steps until the density parameter inversion result meets the requirement. According to the method, the density inversion accuracy can be improved, and description and interpretation of oil and gas reservoirs are facilitated.

Description

Technical Field

[0001] This invention relates to the field of seismic exploration technology, and more specifically, to a method, apparatus, electronic device, and storage medium for inverting oil and gas reservoir density parameters. Background Technology

[0002] Currently, the most important and commonly used technique for reservoir fluid identification is inversion-based fluid factor extraction. This involves using inversion methods to obtain fluid indicator factors that can indicate the properties of reservoir fluids. Different reservoirs have different fluid indicator factors; generally, the fluid indicator factors for unconventional reservoirs are strongly correlated with density. Unconventional reservoirs typically refer to shale gas, igneous rock, and similar reservoirs. Due to their unique formation processes, conventional fluid factors have a weak ability to reflect the fluid-bearing properties of these reservoirs, while density provides a relatively stronger response to their fluid characteristics. Therefore, density parameter inversion methods are particularly important in the field of unconventional reservoir description.

[0003] Currently, the main technique for obtaining density parameters is pre-stack three-parameter inversion, based on the AKI approximation of the Zoeppritz equation. This involves superimposing P-wave and S-wave velocities and densities with the volumetric reflection coefficient R at different angles. P The relationship between (θ) is shown in Formula 1. Construct the objective function, perform simultaneous inversion of the three parameters, and obtain the density parameters.

[0004]

[0005] In the formula, θ represents the incident angle, Vs represents the shear wave velocity, Vp represents the longitudinal wave velocity, ΔVs represents the change in shear wave velocity, ΔVp represents the change in longitudinal wave velocity, ρ represents the average density, and Δρ represents the density change on both sides of the formation interface.

[0006] However, in the three-parameter inversion process, density is not sensitive to changes in the angle reflection coefficient, resulting in high uncertainty and low resolution of the density parameters in the inversion results, making it impossible to effectively use the density inversion results to complete subsequent interpretation work.

[0007] The information disclosed in the background section of this invention is intended only to enhance the understanding of the general background of this invention, and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Summary of the Invention

[0008] The purpose of this invention is to propose a method, apparatus, electronic device, and storage medium for inverting density parameters of oil and gas reservoirs. This invention utilizes the close relationship between specific and large-angle data and density in the Fatti approximation formula, thereby improving the accuracy of density inversion and making it more conducive to the description and interpretation of oil and gas reservoirs.

[0009] To achieve the above objectives, in a first aspect, the present invention proposes a method for inverting oil and gas reservoir density parameters, comprising:

[0010] S1: Select stacked seismic data at near and intermediate angles, and perform two-parameter inversion based on the Fatti two-terminal approximation formula to obtain the P-wave impedance and S-wave impedance, wherein the P-wave impedance is the product of the P-wave velocity and density, and the S-wave impedance is the product of the S-wave velocity and density.

[0011] S2: Using the Fatti three-term approximation formula, perform three-parameter forward modeling of the angle of the far-angle seismic data, the P-wave impedance, the S-wave impedance and the initial density model to obtain forward-modeled far-angle seismic data.

[0012] S3: Using the residual between the original remote-angle seismic data and the forward-modeled remote-angle seismic data, perform conventional linear inversion with density parameters as the target to obtain the density parameter update amount, and combine the density parameter update amount with the initial density model to generate the density parameter inversion result;

[0013] S4: Substitute the density parameter inversion result as prior information into S1, and repeat S1-S3 until the density parameter inversion result meets the requirements.

[0014] Optionally, the Fatti two-term approximation formula is:

[0015]

[0016] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S The average value of the transverse wave impedance, ΔI P , △I S V represents the changes in P-wave velocity and S-wave velocity on both sides of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0017] Optionally, the Fatti three-term approximation formula is:

[0018]

[0019] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S Let ρ represent the average transverse wave impedance, ρ represent the average density, and ΔI represent the average transverse wave impedance. P , △I S Δρ and Δρ represent the changes in P-wave velocity, S-wave velocity, and density on either side of the formation interface, respectively.S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0020] Optionally, the three-parameter forward modeling method employs a forward modeling method based on a convolutional model.

[0021] Optionally, before executing S1, the following may also be included:

[0022] Based on the incident angle, the raw seismic data is divided into far-angle, intermediate-angle, and near-angle seismic data; among them, near-angle seismic data has an incident angle of less than 20 degrees, intermediate-angle seismic data has an incident angle of 20 to 40 degrees, and far-angle seismic data has an incident angle greater than 40 degrees. Secondly, this invention proposes an electronic device, which includes:

[0023] At least one processor; and,

[0024] A memory communicatively connected to the at least one processor; wherein,

[0025] The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the oil and gas reservoir density parameter inversion method described in the first aspect.

[0026] Thirdly, the present invention proposes a non-transitory computer-readable storage medium storing computer instructions for causing a computer to execute the oil and gas reservoir density parameter inversion method described in the first aspect.

[0027] Fourthly, this invention proposes an oil and gas reservoir density parameter inversion device, comprising:

[0028] The two-parameter inversion module is used to select stacked seismic data at near and intermediate angles, and perform two-parameter inversion based on the Fatti two-term approximation formula to obtain the P-wave impedance and S-wave impedance, wherein the P-wave impedance is the product of the P-wave velocity and density, and the S-wave impedance is the product of the S-wave velocity and density.

[0029] The three-parameter forward modeling module is used to perform three-parameter forward modeling of the angle, P-wave impedance, S-wave impedance and density initial model of the far-angle seismic data using the Fatti three-term approximation formula to obtain forward modeled far-angle seismic data.

[0030] The residual density inversion module is used to perform conventional linear inversion with density parameters as the target by utilizing the residuals between the original far-angle seismic data and the forward-modeled far-angle seismic data to obtain the density parameter update. The density parameter update is then combined with the initial density model to generate the density parameter inversion result. The density parameter inversion result is then used as prior information and substituted into the two-parameter inversion module. The calculation is repeated through the two-parameter inversion module, the three-parameter forward modeling module, and the residual density inversion module until the density parameter inversion result meets the requirements.

[0031] Optionally, the Fatti two-term approximation formula is:

[0032]

[0033] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S The average value of the transverse wave impedance, ΔI P , △I S V represents the changes in P-wave velocity and S-wave velocity on both sides of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0034] Optionally, the Fatti three-term approximation formula is:

[0035]

[0036] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S Let ρ represent the average transverse wave impedance, ρ represent the average density, and ΔI represent the average transverse wave impedance. P , △I S Δρ and Δρ represent the changes in P-wave velocity, S-wave velocity, and density on either side of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0037] The beneficial effects of this invention are as follows:

[0038] The method of this invention first selects near- and mid-angle stacked data, and obtains stable high-resolution inversion results of P-wave and S-wave impedance based on the Fatti two-term approximation formula. Then, density parameter inversion (hereinafter referred to as residual density inversion) is performed based on the residuals of far-angle forward modeling based on P-wave and S-wave impedance and actual far-angle seismic data. After obtaining the density inversion results, as prior information, P-wave and S-wave impedance inversion and subsequent residual density inversion are performed again based on the Fatti two-term approximation formula. The process is iterated to obtain the final density inversion results. This invention utilizes the specific and large-angle data and the close relationship between density in the Fatti approximation formula, which improves the accuracy of density inversion and is more conducive to the description and interpretation of oil and gas reservoirs.

[0039] The system of the present invention has other features and advantages that will be apparent from or will be set forth in detail in the accompanying drawings and following detailed description, which together serve to explain the particular principles of the invention. Attached Figure Description

[0040] The above and other objects, features and advantages of the present invention will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0041] Figure 1a This is a schematic diagram showing the degree of agreement between the AKI approximation formula and the Zoeppritz equation as a function of angle.

[0042] Figure 1b A schematic diagram showing the degree of agreement between the Fatti two-term approximation formula and the Zoeppritz equation as a function of angle;

[0043] Figure 1c A schematic diagram showing the degree of agreement between the Fatti three-term approximation formula and the Zoeppritz equation as a function of angle;

[0044] Figure 2 This is a flowchart of an oil and gas reservoir density parameter inversion method according to an embodiment of the present invention.

[0045] Figure 3 This is a schematic diagram of the well connection lines within the study area in one embodiment of the present invention.

[0046] Figure 4 This is a cross-section of the well line in one embodiment of the present invention (including well line seismic data and the location of the target layer).

[0047] Figure 5a This is a density inversion result obtained using the method of the present invention in one embodiment of the present invention.

[0048] Figure 5b This is a density inversion result obtained using conventional methods in one embodiment of the present invention. Detailed Implementation

[0049] Research has shown that the Fatti two-term approximation formula (the first two terms in Formula 2) has a high degree of agreement with the Zoeppritz equation within 30 degrees, indicating that near and mid-angle data are only suitable for inverting P-wave and S-wave impedance.

[0050]

[0051] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S Let ρ represent the average transverse wave impedance, ρ represent the average density, and ΔI represent the average transverse wave impedance. P , △I S Δρ and Δρ represent the changes in P-wave velocity, S-wave velocity, and density on either side of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0052] Figure 1a This is the variation of the degree of agreement between the AKI approximation formula and the Zoeppritz equation with the angle; Figure 1b The graph shows the variation of the agreement between the Fatti two-term approximation formula and the Zoeppritz equation with the angle. It can be seen from the graph that a deviation occurs after 30 degrees. This is because the Fatti two-term approximation formula does not include the density term, which causes insufficient information. Figure 1c The variation of the Fatti three-term approximation formula (all three terms in Formula 2) with the Zoeppritz equation as a function of angle shows that the information is completed and the degree of agreement is high after adding the density term. Figures 1a-1c It has been demonstrated that density inversion based on far-angle data using the Fatti equation is more targeted, and far-angle seismic data is more sensitive to density parameters (where incident angles less than 20 degrees are near-angle data, incident angles of 20 to 40 degrees are intermediate-angle data, and incident angles greater than 40 degrees are far-angle data).

[0053] Accordingly, this invention proposes a method for inverting oil and gas reservoir density, which is carried out in two steps. First, near- and mid-angle partially stacked data are selected, and stable high-resolution inversion results of P-wave and S-wave impedance are obtained based on the Fatti two-term approximation formula. Then, density parameters are inverted based on the residuals of far-angle forward modeling based on P-wave and S-wave impedance and actual far-angle seismic data (hereinafter referred to as residual density inversion). After obtaining the density inversion results, as prior information, P-wave and S-wave impedance inversion based on the Fatti two-term formula and subsequent residual density inversion are performed again. The process is iterated to obtain the final density inversion results.

[0054] The invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0055] Example 1

[0056] like Figure 2 As shown, the present invention provides a method for inverting oil and gas reservoir density parameters, comprising:

[0057] S1: Select stacked seismic data at near and intermediate angles, and perform two-parameter inversion based on the Fatti two-terminal approximation formula to obtain the P-wave impedance and S-wave impedance, wherein the P-wave impedance is the product of the P-wave velocity and density, and the S-wave impedance is the product of the S-wave velocity and density.

[0058] The two-term approximation formula for Fatti is as follows:

[0059]

[0060] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S The average value of the transverse wave impedance, ΔI P , △I S V represents the changes in P-wave velocity and S-wave velocity on both sides of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0061] The input data used in this step should only include near- and mid-range angle superimposed seismic data, rather than conventional near-, mid-, and far-range angle data. The P-wave and S-wave impedances can be obtained through conventional inversion for later use.

[0062] S2: Using the Fatti three-term approximation formula, perform three-parameter forward modeling of the angle of the far-angle seismic data, the P-wave impedance, the S-wave impedance and the initial density model to obtain forward-modeled far-angle seismic data.

[0063] The three approximation formulas for Fatti are as follows:

[0064]

[0065] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S Let ρ represent the average transverse wave impedance, ρ represent the average density, and ΔI represent the average transverse wave impedance. P , △I S Δρ and Δρ represent the changes in P-wave velocity, S-wave velocity, and density on either side of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0066] In this step, the forward modeling method can be based on the convolution model. This is a conventional method. It uses the Fatti three-term formula, the angle of the far-angle data, the longitudinal and transverse wave impedance data obtained in step S1, and the initial density model to perform forward modeling to obtain far-off forward modeling data.

[0067] S3: Using the residual between the original remote-angle seismic data and the forward-modeled remote-angle seismic data, perform conventional linear inversion with density parameters as the target to obtain the density parameter update amount, and combine the density parameter update amount with the initial density model to generate the density parameter inversion result;

[0068] This step utilizes the residual between the real data from a distance and the forward modeling data, with density parameters as the target, to perform conventional linear inversion, obtain the density parameter update, and combine it with the initial density model to generate density parameter inversion results.

[0069] S4: Use the density parameter inversion result as prior information and repeat S1-S3 until the density parameter inversion result meets the requirements.

[0070] Specifically, the density inversion result obtained in S3 is substituted into step S1, and S1-S3 are repeated until the inversion result meets the requirements. That is, the density inversion result obtained in S3 is used as prior information to perform P-wave and S-wave impedance inversion based on the Fatti two-term formula, followed by residual density inversion, iterating cyclically to obtain the final density inversion result. After the density parameter inversion result meets the requirements, the final P-wave, S-wave impedance, and density inversion results are output.

[0071] In this embodiment, before executing S1, the following is also included:

[0072] Based on the incident angle, the raw seismic data is divided into far-angle, intermediate-angle, and near-angle seismic data; among them, the incident angle is less than 20 degrees and is near-angle seismic data, the incident angle is 20 to 40 degrees and is intermediate-angle seismic data, and the incident angle is greater than 40 degrees and is far-angle seismic data.

[0073] This method fully considers the characteristics of the Fatti approximation formula at near-mid angles, i.e., the contribution of the density term can be ignored; at the same time, it takes into account the sensitivity of far-angle data to density; through iterative methods, it continuously optimizes the inversion quality of P-wave and S-wave impedance and density parameters, and the obtained density parameter inversion results are helpful for the description of oil and gas reservoirs.

[0074] Example 2

[0075] The method of this invention has achieved good results in the application of unconventional igneous reservoirs in Northeast China, confirming the feasibility of the invention. Figure 3 As shown, this is a well-connecting line within this area. Figure 4 This is a cross-sectional view of the well lines. The image shows three wells in total. The well on the left encountered a relatively good reservoir, the middle well encountered a thin reservoir, and the well on the right encountered a slightly thicker reservoir. Through comparison... Figure 5a The density inversion data obtained by the method of the present invention are shown below. Figure 5b As shown in the density inversion data obtained through conventional three-parameter inversion, the results obtained using the method of this invention show significant improvements in the consistency between density and well logging data, reservoir distribution characteristics, and profile resolution. This confirms the feasibility and application potential of the method of this invention.

[0076] Example 3

[0077] This embodiment provides an oil and gas reservoir density parameter inversion device, including:

[0078] The two-parameter inversion module is used to select stacked seismic data at near and intermediate angles, and perform two-parameter inversion based on the Fatti two-term approximation formula to obtain the P-wave impedance and S-wave impedance, wherein the P-wave impedance is the product of the P-wave velocity and density, and the S-wave impedance is the product of the S-wave velocity and density.

[0079] The three-parameter forward modeling module is used to perform three-parameter forward modeling of the angle, P-wave impedance, S-wave impedance and density initial model of the far-angle seismic data using the Fatti three-term approximation formula to obtain forward modeled far-angle seismic data.

[0080] The residual density inversion module is used to perform conventional linear inversion with density parameters as the target by utilizing the residuals between the original far-angle seismic data and the forward-modeled far-angle seismic data to obtain the density parameter update. The density parameter update is then combined with the initial density model to generate the density parameter inversion result. Furthermore, the density parameter inversion result is used as prior information and substituted into the two-parameter inversion module. The relevant calculations are then repeatedly performed through the two-parameter inversion module, the three-parameter forward modeling module, and the residual density inversion module until the density parameter inversion result meets the requirements.

[0081] The two-term approximation formula for Fatti is as follows:

[0082]

[0083] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S The average value of the transverse wave impedance, ΔI P , △I S V represents the changes in P-wave velocity and S-wave velocity on both sides of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0084] The Fatti three-term approximation formula is as follows:

[0085]

[0086] In the formula, R(θ) represents the reflection coefficient of the PP wave, θ represents the incident angle, and I P I represents the average value of the underground P-wave impedance. S Let ρ represent the average transverse wave impedance, ρ represent the average density, and ΔI represent the average transverse wave impedance. P , △I S Δρ and Δρ represent the changes in P-wave velocity, S-wave velocity, and density on either side of the formation interface, respectively. S Indicates transverse wave velocity, V P This indicates the longitudinal wave velocity.

[0087] Example 4

[0088] This embodiment provides an electronic device, the electronic device comprising:

[0089] At least one processor; and,

[0090] A memory communicatively connected to the at least one processor; wherein,

[0091] The memory stores instructions that can be executed by the at least one processor, which enables the at least one processor to perform the oil and gas reservoir density parameter inversion method described in Example 1.

[0092] An electronic device according to embodiments of the present disclosure includes a memory and a processor. The memory is used to store non-transitory 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. The non-volatile memory may, for example, include read-only memory (ROM), hard disk, flash memory, etc.

[0093] The processor may be a central processing unit (CPU) or other form of processing unit with 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 this disclosure, the processor is used to execute computer-readable instructions stored in the memory.

[0094] Those skilled in the art will understand that, in order to solve the technical problem of how to achieve a good user experience, this embodiment may also include well-known structures such as communication buses and interfaces, and these well-known structures should also be included within the protection scope of this disclosure.

[0095] For a detailed description of this embodiment, please refer to the corresponding descriptions in the foregoing embodiments, which will not be repeated here.

[0096] Example 5

[0097] This embodiment provides a non-transitory computer-readable storage medium that stores computer instructions for causing a computer to execute the oil and gas reservoir density parameter inversion method described in Embodiment 1.

[0098] A computer-readable storage medium according to embodiments of the present disclosure stores non-transitory computer-readable instructions. When these non-transitory computer-readable instructions are executed by a processor, all or part of the steps of the methods described in the foregoing embodiments of the present disclosure are performed.

[0099] The aforementioned 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 portable hard drive), media with built-in rewritable non-volatile memory (e.g., memory card), and media with built-in ROM (e.g., ROM cartridge).

[0100] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method of density parameter inversion of a hydrocarbon reservoir, characterized in that, The method comprises the following steps: S1: selecting near-angle and middle-angle stacked seismic data, performing two-parameter inversion based on a Fatti two-term approximation formula to obtain a P-wave impedance and a S-wave impedance, wherein the P-wave impedance is a product of a P-wave velocity and a density, and the S-wave impedance is a product of a S-wave velocity and the density; S2: performing three-parameter forward modeling on an angle of far-angle seismic data, the P-wave impedance, the S-wave impedance and a density initial model by using a Fatti three-term approximation formula to obtain forward far-angle seismic data; S3: performing a conventional linear inversion on a residual between far-angle original seismic data and the forward far-angle seismic data to obtain a density parameter update, and combining the density parameter update with the density initial model to generate a density parameter inversion result; S4: substituting the density parameter inversion result into S1 as prior information, and repeatedly performing S1-S3 until the density parameter inversion result meets a requirement.

2. The hydrocarbon reservoir density parameter inversion method of claim 1, wherein, The Fatti two-term approximation formula is as follows: where R(θ) represents a PP wave reflection coefficient, θ represents an incident angle, I P represents an average value of a subsurface P-wave impedance, I S represents an average value of a S-wave impedance, ΔI P , ΔI S respectively represent a P-wave velocity variation amount, a S-wave velocity variation amount on both sides of a formation boundary surface, V S represents a S-wave velocity, V P represents a P-wave velocity.

3. The hydrocarbon reservoir density parameter inversion method of claim 1, wherein, The Fatti three-term approximation formula is as follows: where R(θ) represents a PP wave reflection coefficient, θ represents an incident angle, I P represents an average value of a subsurface P-wave impedance, I S represents an average value of a S-wave impedance, ρ represents an average value of a density, ΔI P , ΔI S , and Δρ represent a P-wave velocity variation amount, a S-wave velocity variation amount, and a density variation amount on both sides of a formation boundary, V S represents a S-wave velocity, V P represents a P-wave velocity.

4. The hydrocarbon reservoir density parameter inversion method of claim 1, wherein, The three-parameter forward modeling method adopts a forward modeling method based on a convolution model.

5. The hydrocarbon reservoir density parameter inversion method of claim 1, wherein, Before S1 is performed, the method further comprises the following steps: dividing the original seismic data into far-angle, middle-angle and near-angle seismic data according to an incident angle; wherein the incident angle less than 20 degrees is the near-angle seismic data, the incident angle 20 to 40 degrees is the middle-angle seismic data, and the incident angle greater than 40 degrees is the far-angle seismic data.

6. An electronic device, comprising: The electronic device comprises: at least one processor; and a memory connected with the at least one processor in communication; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the oil and gas reservoir density parameter inversion method in any one of claims 1-5.

7. A non-transitory computer-readable storage medium, comprising: The non-transitory computer readable storage medium stores computer instructions for causing a computer to perform the oil and gas reservoir density parameter inversion method in any one of claims 1-4.

8. An oil and gas reservoir density parameter inversion device, characterized in that, The method comprises the following steps: a two-parameter inversion module configured to select near-angle and middle-angle stacked seismic data, perform two-parameter inversion based on a Fatti two-term approximation formula to obtain a P-wave impedance and a S-wave impedance, wherein the P-wave impedance is a product of a P-wave velocity and a density, and the S-wave impedance is a product of a S-wave velocity and the density; a three-parameter forward modeling module configured to perform three-parameter forward modeling on an angle of far-angle seismic data, the P-wave impedance, the S-wave impedance and a density initial model by using a Fatti three-term approximation formula to obtain forward far-angle seismic data; a residual density inversion module configured to perform a conventional linear inversion on a residual between far-angle original seismic data and the forward far-angle seismic data to obtain a density parameter update, combine the density parameter update with the density initial model to generate a density parameter inversion result, and substitute the density parameter inversion result into the two-parameter inversion module as prior information, and repeatedly perform calculation through the two-parameter inversion module, the three-parameter forward modeling module and the residual density inversion module until the density parameter inversion result meets a requirement.

9. The hydrocarbon reservoir density parameter inversion apparatus of claim 1, wherein, The Fatti two-term approximation formula is: where R(θ) represents a PP wave reflection coefficient, θ represents an incident angle, I P represents an average value of a subsurface P-wave impedance, I S represents an average value of a S-wave impedance, ΔI P , ΔI S respectively represent a P-wave velocity variation amount, a S-wave velocity variation amount on both sides of a formation boundary, V S represents a S-wave velocity, V P represents a P-wave velocity.

10. The hydrocarbon reservoir density parameter inversion apparatus of claim 1, wherein, The Fatti three-term approximation formula is: where R(θ) represents a PP wave reflection coefficient, θ represents an incident angle, I P represents an average value of a P-wave impedance, I S represents an average value of a S-wave impedance, ρ represents an average value of a density, ΔI P , ΔI S , and Δρ represent a P-wave velocity variation amount, a S-wave velocity variation amount, and a density variation amount, respectively, on both sides of a formation boundary, V S represents a S-wave velocity, V P represents a P-wave velocity.

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