A method for evaluating fidelity of seismic data based on sandstone reservoir structure pattern

Abstract

This invention relates to a method for evaluating the fidelity of seismic data based on sandstone reservoir structure models, comprising the following steps: conducting fine-grained well-seismic calibration of the internal structure of the reservoir using well logging and seismic data; determining the target reservoir structure pattern using rock physical analysis results; establishing a typical geological model based on the reservoir structure pattern, and conducting forward modeling analysis of geological models for different reservoir structure patterns based on the fine-grained well-seismic calibration results; and performing seismic data structure fidelity analysis based on the forward modeling analysis results. This method for evaluating the fidelity of seismic data based on sandstone reservoir structure models guides the analysis of the internal structure of reservoir sand bodies based on seismic data, optimizes the development well network, and provides important technical support for the efficient development and scheme adjustment of underground oil and gas reservoirs.

Description

Technical Field

[0001] This invention relates to the fields of well logging, seismic, and geological integrated research in oilfield development, specifically to a method for evaluating the fidelity of seismic data based on sandstone reservoir structure models. Background Technology

[0002] As exploration and development deepen, the demand for precise understanding of the internal structure of sedimentary bodies increases. This necessitates detailed studies of reservoir internal structures to guide the optimization of injection-production well networks and the tapping of remaining oil potential. For offshore sparse well networks, analyzing the internal structure of sedimentary bodies based on seismic data is particularly crucial, directly impacting efficient reserve utilization, well network deployment, injection-production effectiveness, and the prediction of remaining oil distribution. This places higher demands on the structural fidelity of seismic data. Therefore, in seismic data processing, it is essential to focus not only on amplitude preservation but also on structural fidelity.

[0003] Currently, the evaluation of seismic reprocessed data mainly focuses on qualitative or quantitative assessment of the amplitude preservation of seismic data from the perspective of reservoir thickness prediction, and then conducts structural and reservoir studies. However, there is still no systematic method for evaluating the structural fidelity of seismic data by integrating geology and geophysics. Summary of the Invention

[0004] To address the aforementioned issues, the purpose of this invention is to provide a method for evaluating the fidelity of seismic data based on sandstone reservoir structure models. This method integrates geological understanding into the evaluation of seismic data quality, guides the fine processing of seismic data, and ultimately yields optimized seismic data processing results that better reflect the internal structure of the reservoir, making the research results more consistent with sedimentary patterns and geological characteristics.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for evaluating the fidelity of seismic data based on a sandstone reservoir structure model, comprising the following steps:

[0007] Utilizing well logging and seismic data, conduct fine-grained well seismic calibration targeting the internal structure of reservoirs;

[0008] Determine the target reservoir structure pattern using rock physical analysis results;

[0009] Based on the aforementioned reservoir structure patterns, typical geological models were established, and forward modeling analyses of geological models with different reservoir structure patterns were conducted based on the fine well seismic calibration results.

[0010] Based on the forward modeling results of the geological model, a seismic data structure fidelity analysis was performed.

[0011] Furthermore, it also includes the following steps:

[0012] The fidelity analysis of seismic data structure was verified based on production dynamic data.

[0013] Furthermore, the detailed well-seismic calibration using well logging and seismic data to examine the internal structure of the reservoir includes:

[0014] Based on well logging and 3D seismic data, we conducted spectral characteristic analysis of seismic data to identify the effective low-frequency band, main frequency band, effective high-frequency band, and high-frequency noise band of seismic data.

[0015] Based on the analysis results of the seismic data spectrum characteristics, fine well seismic calibration was carried out under different dominant frequency wavelets to clarify the frequency band of reservoir structure response.

[0016] Furthermore, the determination of the target reservoir structure pattern using rock physical analysis results includes:

[0017] Well logging curves are normalized and standardized.

[0018] Based on the normalization and standardization results, key wells were selected to conduct target layer logging petrophysical analysis to clarify the velocity and density characteristics of various lithologies.

[0019] The target reservoir structure pattern is analyzed based on the velocity and density characteristics of the various lithologies.

[0020] Furthermore, the forward modeling analysis of geological models for different reservoir structure styles based on the fine well seismic calibration results specifically includes:

[0021] Based on the response frequency band of the reservoir structure, forward modeling analysis of geological models of different reservoir structure styles was carried out to clarify the seismic response characteristics of different reservoir structure styles.

[0022] Furthermore, based on the forward modeling analysis results, a seismic data structure fidelity analysis is performed:

[0023] Based on the forward modeling results, typical wells were selected along different directions to construct well-connected geological profiles and corresponding well-connected seismic profiles.

[0024] Based on the geological profiles of the wells, conduct comparative geological analysis of the wells guided by geological models;

[0025] Based on the geological comparison analysis results, a seismic reservoir structure fidelity analysis was conducted on the seismic profiles of the interconnected wells.

[0026] Furthermore, the analysis of seismic data structure fidelity based on production dynamic data includes:

[0027] Select optimal injection-production well pairs in the target area and conduct injection-production effect characteristic analysis;

[0028] Based on constructing seismic profiles of injection and production wells connected together;

[0029] Based on the obtained seismic profiles of the connected wells, a seismic reservoir structure preservation quality control analysis was conducted.

[0030] Secondly, the present invention also provides a seismic data fidelity evaluation device based on a sandstone reservoir structure model, comprising:

[0031] The first processing unit uses well logging and seismic data to conduct fine well seismic calibration of the internal structure of the reservoir;

[0032] The second processing unit uses the results of rock physical analysis to determine the target reservoir structure pattern;

[0033] The third processing unit establishes a typical geological model based on the reservoir structure pattern and conducts forward modeling analysis of geological models with different reservoir structure patterns based on the fine well seismic calibration results.

[0034] The fourth processing unit performs a seismic data structure fidelity analysis based on the forward modeling results.

[0035] Thirdly, the present invention also provides a computer-readable storage medium storing computer instructions, which, when executed by a processor, implement the aforementioned method for evaluating the fidelity of seismic data based on sandstone reservoir structure models.

[0036] Fourthly, the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, it implements the aforementioned method for evaluating the fidelity of seismic data based on sandstone reservoir structure models. Due to the adoption of the above technical solutions, the present invention has the following advantages:

[0037] A typical reservoir structure geological model was constructed through well-seismic interaction, and its seismic response characteristics were clarified through forward modeling. Based on this, combined with well-to-well geological comparison analysis and injection-production well pair dynamic analysis, the structural fidelity of seismic data was evaluated. Furthermore, the seismic data guided the analysis of the internal structure of reservoir sand bodies, optimized the development well network, and provided important technical support for the efficient development and scheme adjustment of underground oil and gas reservoirs.

[0038] In addition, it has the following advantages:

[0039] A set of seismic data structure preservation evaluation methods has been developed, which makes up for the shortcomings of seismic fidelity evaluation based solely on seismic amplitude;

[0040] By combining geological models, geological analysis, and production dynamic monitoring data, we can conduct seismic data preservation evaluation and analysis, guide the reprocessing of seismic data, and interpret the results to better reflect the underground geological characteristics. Attached Figure Description

[0041] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0042] In the attached diagram:

[0043] Figure 1 This is a flowchart of the seismic data structure fidelity evaluation method based on sandstone reservoir structure model according to the present invention.

[0044] Figure 2 This is a spectral characteristic map of earthquakes.

[0045] Figure 3 This is a fine-grained well seismic calibration diagram for reservoir structure.

[0046] Figure 4 This is a geological model and its forward modeling diagram.

[0047] Figure 5 Geological profiles of the wells and corresponding seismic profiles of the wells.

[0048] Figure 6 Figure showing the monitoring results of injection and production wells. Detailed Implementation

[0049] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary 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 to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0050] This invention provides a method for evaluating the fidelity of seismic data based on sandstone reservoir structure models, comprising the following steps: conducting fine-grained well-seismic calibration of the internal structure of the reservoir using well logging and seismic data; determining the target reservoir structure pattern using rock physics analysis results; establishing a typical geological model based on the reservoir structure pattern, and conducting forward modeling analysis of geological models with different reservoir structure patterns based on the fine-grained well-seismic calibration results; and performing seismic data structure fidelity analysis based on the forward modeling analysis results. This method for evaluating the fidelity of seismic data based on sandstone reservoir structure models guides the analysis of the internal structure of reservoir sand bodies based on seismic data, optimizes the development well network, and provides important technical support for the efficient development and scheme adjustment of underground oil and gas reservoirs.

[0051] Example 1

[0052] like Figure 1 As shown, Embodiment 1 of the present invention provides a method for evaluating the fidelity of seismic data based on a sandstone reservoir structure model, comprising the following steps:

[0053] S1. Utilizing well logging and seismic data, conduct fine-grained well-seismic calibration targeting the internal structure of the reservoir. The specific steps are as follows:

[0054] S1-1: Based on well logging and 3D seismic data, conduct seismic data spectral characteristic analysis to identify the effective low frequency, dominant frequency band, effective high frequency, and high frequency noise band of seismic data;

[0055] S1-2: Based on the seismic effective spectrum characteristic analysis results of step S1-1, conduct fine well seismic calibration under different dominant frequency wavelets to clarify the reservoir structure response frequency band.

[0056] Depend on Figure 2 It can be seen that the effective low-frequency band of 3D seismic analysis is 5-10Hz, the effective high-frequency band is 50-70Hz, the dominant frequency is 25Hz, and frequencies above 75Hz are dominated by high-frequency noise. The analysis results can be used as a reference frequency band for post-stack seismic optimization processing.

[0057] Depend on Figure 3 It can be seen that when the dominant frequency of the wavelet is 25Hz, both the synthetic record of the target sand body and the original seismic event exhibit the reflection characteristics of complex waves; when the dominant frequency of the wavelet is 30Hz, 35Hz, and 40Hz (within the effective high-frequency band), the complex wave of the synthetic record of the target sand body is opened, which matches the two sets of reservoir sand bodies actually encountered in the well.

[0058] S2. Determine the target reservoir structure pattern using the results of rock physics analysis, establish a typical geological model based on the reservoir structure pattern, and conduct forward modeling analysis of geological models for different reservoir structure patterns based on the results of fine well seismic calibration.

[0059] Step 2-1: Normalization and standardization of well logging curves;

[0060] Step 2-2: Based on the processing results of Step 2-1, select key wells to carry out target layer logging petrophysical analysis to clarify the velocity and density characteristics of various lithologies;

[0061] Step 2-3: Based on the processing results of Step 2-1, select key wells to analyze the reservoir sand body structure of the target layer and establish a typical geological model;

[0062] Step 2-4: Based on the geological model constructed in Step 2-2 and combined with the rock material analysis results in Step 2-1, forward modeling analysis was carried out using a 35Hz dominant frequency to clarify the seismic response characteristics of different reservoir sand body structural styles.

[0063] Depend on Figure 4It can be seen that when Sand-1 and Sand-2 appear in a overlapping form and Sand-3, the late-stage channel sand body, does not develop, only the intensity of earthquake amplitude changes, that is, the amplitude weakens at the overlapping channel. When Sand-3, the late-stage channel sand body, develops, in addition to the intensity of earthquake amplitude, there is also a misalignment of the same-direction earthquake reflection axis.

[0064] S3. Based on the forward modeling results, conduct a seismic data structure fidelity analysis. The specific steps are as follows:

[0065] Step 3-1: Select typical wells along the direction perpendicular to the river channel to construct a series of well geological profiles and corresponding series of well seismic profiles;

[0066] Step 3-2: Conduct a comparative geological analysis of wells based on the geological profiles from Step 3-1, guided by the geological model.

[0067] Step 3-3: Based on the geological comparison analysis results of Step 3-2, conduct seismic reservoir structure fidelity analysis on the seismic profiles of the connected wells.

[0068] Depend on Figure 5 It is known that both Well-1 and Well-2 encountered two sets of composite sand bodies. The early-stage channels Channel_1 and Channel_2 encountered by Well-1 and Well-2, respectively, are not contemporaneous channels, exhibiting different logging characteristics. However, the late-stage channel Channel_3 encountered by both Well-1 and Well-2 has similar logging characteristics, indicating it is a contemporaneous channel. Comparing the seismic profiles of the interconnected wells before and after processing, the optimized seismic data clearly reflects the lateral correspondence between the drilled channel sand bodies in Well-1 and Well-2, consistent with geological understanding and forward modeling analysis.

[0069] S4. Verify the fidelity of seismic data structure based on production dynamic data. The specific steps are as follows:

[0070] Step 4-1: Select the best injection and production wells in the target area, Well-1 (water injection well) and Well-2 (oil production well), and conduct injection and production effect characteristic analysis;

[0071] Step 4-2: Construct a seismic profile connecting Well-1 and Well-2 based on Step 4-1;

[0072] Step 4-3: Based on Step 4-1, conduct seismic reservoir structure preservation quality control analysis on the well-connected seismic profiles obtained in Step 4-2.

[0073] Depend on Figure 6It can be seen that Well-1 began water injection on January 16, 2017. Before water injection, the fluid volume of the production well Well-2 decreased slowly; after water injection, the fluid volume of Well-2 rebounded significantly, and after the water injection volume gradually decreased, its fluid volume decreased slowly; after Well-1 stopped injection, the fluid volume of Well-2 decreased significantly, indicating that the connectivity between Well-1 and Well-2 was good. This further proves that seismic optimization processing can accurately reflect the reservoir structure relationship.

[0074] Example 2

[0075] Embodiment 2 of the present invention also provides a seismic data fidelity evaluation device based on sandstone reservoir structure model, comprising:

[0076] The first processing unit uses well logging and seismic data to conduct fine well seismic calibration of the internal structure of the reservoir;

[0077] The second processing unit uses the results of rock physical analysis to determine the target reservoir structure pattern;

[0078] The third processing unit establishes a typical geological model based on the reservoir structure pattern and conducts forward modeling analysis of geological models with different reservoir structure patterns based on the fine well seismic calibration results.

[0079] The fourth processing unit performs a seismic data structure fidelity analysis based on the forward modeling results.

[0080] Example 3

[0081] Embodiment 3 of the present invention provides a computer-readable storage medium storing computer instructions, which are used to implement the seismic data fidelity evaluation method based on sandstone reservoir structure model described in Embodiment 1 when executed by a processor.

[0082] Example 4

[0083] Embodiment 4 of the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the seismic data fidelity evaluation method based on sandstone reservoir structure model as described in Embodiment 1.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications 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.

Claims

1. A method for evaluating the fidelity of seismic data based on sandstone reservoir structure models, characterized in that, Includes the following steps: S1. Utilizing well logging and seismic data, conduct fine-grained well-seismic calibration targeting the internal structure of the reservoir. The specific steps are as follows: S1-1: Based on well logging and 3D seismic data, conduct seismic data spectral characteristic analysis to identify the effective low-frequency band, main frequency band, effective high-frequency band, and high-frequency noise band of seismic data; S1-2: Based on the analysis results of the spectral characteristics of the seismic data, conduct fine well seismic calibration under different dominant frequency wavelets to clarify the frequency band of reservoir structure response; S2. Determine the target reservoir structure pattern using rock physics analysis results, establish a typical geological model based on the reservoir structure pattern, and conduct forward modeling analysis of geological models for different reservoir structure patterns based on the fine well seismic calibration results, including the following steps: Step 2-1: Normalization and standardization of well logging curves; Step 2-2: Based on the processing results of Step 2-1, select key wells to carry out target layer logging petrophysical analysis to clarify the velocity and density characteristics of various lithologies; Step 2-3: Based on the processing results of Step 2-1, select key wells to analyze the reservoir sand body structure of the target layer and establish a typical geological model; Step 2-4: Based on the typical geological model established in Step 2-3, and combined with the rock material analysis results in Step 2-2, forward modeling analysis is carried out using a 35Hz dominant frequency to clarify the seismic response characteristics of different reservoir sand body structural styles; S3. Based on the forward modeling results of the geological model, conduct a seismic data structure fidelity analysis, including the following specific steps: Step 3-1: Select typical wells along the direction perpendicular to the river channel to construct a series of well geological profiles and corresponding series of well seismic profiles; Step 3-2: Conduct a comparative geological analysis of wells based on the geological profiles from Step 3-1, guided by the geological model. Step 3-3: Based on the geological comparison analysis results of Step 3-2, conduct seismic reservoir structure fidelity analysis on the seismic profiles of the interconnected wells; S4. Verify the fidelity of seismic data structure based on production dynamic data. The specific steps are as follows: Step 4-1: Select the optimal injection-production well pair in the target area and conduct injection-production effect characteristic analysis; Step 4-2: Construct seismic profiles of injection-production well pairs based on Step 4-1; Step 4-3: Conduct seismic reservoir structure preservation quality control analysis based on the well-connected seismic profiles obtained in Step 4-2.

2. A computer-readable storage medium, characterized in that, The system contains computer instructions that, when executed by a processor, implement the seismic data fidelity evaluation method based on sandstone reservoir structure model as described in claim 1.

3. A computer device, characterized in that, The invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, when the processor executes the computer program, it implements the seismic data fidelity evaluation method based on sandstone reservoir structure model as described in claim 1.

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