Evaluation method and system for oil and gas storage conditions on periphery of reverse thrust crawler

Abstract

The embodiment of the invention provides a method and a system for evaluating oil and gas storage conditions at the periphery of a back-flushing crawler, and belongs to the technical field of oil exploration. The method comprises the following steps: acquiring basic data of a target area, and identifying geological features based on the basic data; logging data of a target area are collected, and oil and gas storage state recognition is executed based on the logging data; key evaluation index identification is carried out based on the geological features and the oil and gas storage state; and based on the logging data of the target area, assigning each key evaluation index, and based on the assigned key evaluation index, evaluating the oil and gas storage condition. According to the scheme, the relevance and sensitivity of the multi-dimensional data are comprehensively considered, the favorable area, the general area and the unfavorable area can be effectively divided and stored in the complex geological area, and the method has important guiding significance for actual oil-gas exploration and development.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration technology, specifically to a method and system for evaluating oil and gas preservation conditions around thrust-nap belts. Background Technology

[0002] As a crucial component of modern energy, oil and gas resources have always been a core research area in petroleum geology. However, the preservation conditions of oil and gas resources in thrust belts and their surrounding areas are extremely complex. Influenced by multiple factors such as tectonic activity intensity, sedimentary basin evolution, and underground fluid modification, oil and gas reservoirs in this region have undergone multiple phases of formation, accumulation, destruction, and preservation. Current research on oil and gas preservation requires a comprehensive analysis of various geological, physical, and chemical factors to construct a systematic evaluation method.

[0003] In existing technologies, researchers have explored several methods for evaluating hydrocarbon preservation conditions. For example, Ma Yongsheng et al. proposed an evaluation system centered on caprock sealing performance, fault sealing, tectonic intensity, hydrogeological conditions, and underground fluid characteristics for analyzing hydrocarbon preservation conditions in southern marine hydrocarbons; Luo Xiaoquan et al. explored hydrocarbon preservation conditions in the Longmenshan thrust belt of western Sichuan from three aspects: tectonic deformation, caprock characteristics, and hydrogeology. While these studies have revealed key factors affecting hydrocarbon preservation to some extent, they still have the following limitations: 1) Insufficient analysis of the impact of complex structures: The structural development of thrust-nappe zones is complex. Fault development and strike, as well as stratigraphic exposure characteristics, have a significant impact on oil and gas preservation conditions. However, existing methods have failed to systematically study the relationship between faults and preservation conditions, and lack clear quantitative evaluation models.

[0004] 2) Inconsistent selection of key parameters: In existing studies, the selection of evaluation parameters varies with different regions and research objectives, resulting in a complex indicator system with poor practicality, making it difficult to form a universal evaluation framework.

[0005] 3) Insufficient data integration and utilization: Current evaluation methods are still limited in their combined analysis of well logging data, seismic data and drilling data, and do not make full use of key data such as mineralization, formation water type and distance from the main control fault to systematically quantify oil and gas preservation conditions.

[0006] Therefore, existing technologies lack a systematic approach that can comprehensively integrate geological features, structural characteristics, and formation water chemistry in the study of oil and gas preservation conditions in complex structural areas, which cannot meet the reliability and operability requirements of actual production. Summary of the Invention

[0007] The purpose of this invention is to provide a method and system for evaluating the oil and gas preservation conditions around thrust-nap belts, so as to at least solve the problem that existing technologies lack a systematic method that can comprehensively integrate geological features, structural characteristics and formation water chemistry in the study of oil and gas preservation conditions in complex structural areas.

[0008] To achieve the above objectives, the first aspect of the present invention provides a method for evaluating oil and gas preservation conditions around a thrust-nappe zone. The method includes: collecting basic data of a target area and identifying geological features based on the basic data; collecting well logging data of the target area and identifying oil and gas preservation status based on the well logging data; identifying key evaluation indicators based on geological features and oil and gas preservation status; assigning values ​​to each key evaluation indicator based on the well logging data of the target area, and evaluating oil and gas preservation conditions based on the assigned key evaluation indicators.

[0009] Optionally, the basic data of the target area includes: geological data and / or production data; the identification of geological features based on the basic data includes: performing data preprocessing on the basic data, and classifying the preprocessed basic data according to geological feature types to obtain datasets corresponding to geological feature types; performing geological feature identification under the corresponding geological feature type based on the datasets corresponding to each geological feature type; wherein, the geological features include geological background features and geological structural features.

[0010] Optionally, the data preprocessing of the basic data includes: performing data cleaning on the basic data, and identifying redundant and duplicate data after data cleaning; performing filtering on the redundant and duplicate data to obtain preprocessed basic data.

[0011] Optionally, the step of collecting logging data of the target area and performing oil and gas preservation status identification based on the logging data includes: performing data clustering based on the logging data of the target area to obtain multiple datasets; performing data preprocessing on each dataset to obtain a normalized dataset as identification data; and performing oil and gas preservation status identification based on the identification data.

[0012] Optionally, the identification of key evaluation indicators based on geological features and oil and gas preservation status includes: determining the sensitivity of each dataset to the oil and gas preservation status based on the oil and gas preservation status identification results; selecting the top N datasets in terms of sensitivity as sensitive datasets; and determining the corresponding key evaluation indicators based on the sensitive datasets.

[0013] Optionally, the step of determining the sensitivity of each dataset to the influence of the oil and gas preservation status based on the oil and gas preservation status identification results includes: calculating the contribution value of each dataset to the oil and gas preservation status based on the oil and gas preservation status identification results; performing normalization processing on the contribution value of each dataset to generate the corresponding sensitivity of the influence of each dataset.

[0014] Optionally, the key evaluation indicators include any one or more of the following: exposed strata, distance from the main controlling fault, degree of fault development, and chemical characteristics of formation water.

[0015] Optionally, the process of assigning values ​​to each key evaluation indicator based on the logging data of the target area includes: extracting the data information required for each key evaluation indicator based on the logging data of the target area; calling the corresponding assignment rules based on each key evaluation indicator; and executing the corresponding assignment rules based on the extracted data information to obtain the assigned values ​​for each key evaluation indicator.

[0016] Optionally, the scoring rules for exposed strata are based on stratum age, with older strata receiving lower scores; the scoring rules for distance from the main controlling fault are based on the range of well-to-fault distances, with larger ranges receiving higher scores; the scoring rules for fault development degree are based on the degree of fault development, with lower degrees receiving lower scores; and the scoring rules for formation water chemical characteristics are based on salinity range and water type, assigning higher scores to water with higher salinity and CaCl2 as the main water type, and lower scores to water with lower salinity and NaSO4 or MgCl2 as the main water type.

[0017] Optionally, an oil and gas conservation condition evaluation is performed based on the assigned key evaluation indicators, including: adding preset weights to the assigned key evaluation indicators, and performing a weighted summation operation after weighting to obtain the corresponding oil and gas conservation condition evaluation score for the target area; and performing corresponding evaluation level matching in the evaluation library based on the oil and gas conservation condition evaluation score of the target area as the evaluation result output.

[0018] A second aspect of the present invention provides a system for evaluating oil and gas preservation conditions around a thrust-nappe zone. The system includes: a geological identification unit for collecting basic data of a target area and identifying geological features based on the basic data; a state identification unit for collecting well logging data of the target area and performing oil and gas preservation state identification based on the well logging data; an index identification unit for identifying key evaluation indicators based on geological features and oil and gas preservation state; and an evaluation unit for assigning values ​​to each key evaluation indicator based on the well logging data of the target area and performing oil and gas preservation condition evaluation based on the assigned key evaluation indicators.

[0019] A third aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described method for evaluating the oil and gas preservation conditions around the thrust-overlap zone.

[0020] A fourth aspect of the present invention provides an electronic device, the electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for evaluating the oil and gas preservation conditions around the thrust-nap zone.

[0021] The fifth aspect of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method for evaluating the oil and gas preservation conditions around the thrust-overlap zone.

[0022] Through the above technical solution, this invention achieves accurate identification and value analysis of key evaluation indicators by collecting basic data and well logging data of the target area, combined with geological features and oil and gas preservation status identification, significantly improving the scientificity and reliability of oil and gas preservation condition evaluation. Geological feature identification based on basic data provides a comprehensive understanding of the tectonic background of the target area; oil and gas preservation status identification through well logging data effectively quantifies the core influencing factors of preservation conditions; and the value assignment of key evaluation indicators transforms complex geological information into easily analyzable quantitative parameters. Ultimately, the oil and gas preservation condition evaluation based on the assigned key evaluation indicators not only ensures the comprehensiveness of the evaluation process but also makes the regional division results more accurate. This method comprehensively considers the correlation and sensitivity of multidimensional data, and can effectively divide favorable, general, and unfavorable preservation areas in complex geological regions, providing important guidance for actual oil and gas exploration and development.

[0023] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0024] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings: Figure 1 This is a flowchart of the steps of an embodiment of the present invention for evaluating the oil and gas preservation conditions around the thrust-nap zone; Figure 2 This is a flowchart of a specific embodiment of the gas preservation condition evaluation method provided by one embodiment of the present invention; Figure 3 This is a fault distribution map provided by one embodiment of the present invention; Figure 4 This is a graph showing the relationship between mineralization and distance from a major fault, provided by one embodiment of the present invention. Figure 5 This is a surface stratum outcrop distribution map provided by one embodiment of the present invention; Figure 6 This is an asphalt distribution map provided by one embodiment of the present invention; Figure 7 This is a graph showing the evaluation results of oil and gas preservation conditions provided by one embodiment of the present invention; Figure 8 This is a system structure diagram of an evaluation system for oil and gas preservation conditions around the thrust-nap zone provided in one embodiment of the present invention. Detailed Implementation

[0025] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0026] Figure 1 This is a flowchart of a method for evaluating oil and gas preservation conditions around a thrust-nap zone, provided by one embodiment of the present invention. Figure 1 As shown, this invention provides a method for evaluating oil and gas preservation conditions around a thrust-nap zone, the method comprising: Step S10: Collect basic data of the target area and identify geological features based on the basic data.

[0027] Specifically, the basic data of the target area includes: geological data and / or production data; the identification of geological features based on the basic data includes performing data preprocessing on the basic data, classifying the preprocessed basic data according to geological feature types to obtain datasets corresponding to the geological feature types; and performing geological feature identification under the corresponding geological feature type based on the datasets corresponding to each geological feature type; wherein, the geological features include geological background features and geological structural features.

[0028] Furthermore, the data preprocessing of the basic data includes: performing data cleaning on the basic data, and identifying redundant and duplicate data after data cleaning; performing filtering on the redundant and duplicate data to obtain preprocessed basic data.

[0029] In this embodiment of the invention, geological and production data of the target area are collected to provide comprehensive data support for subsequent geological feature identification. The scope of basic data collection is extensive, including historical exploration reports, drilling data, seismic data, and related geological background information. This data can reflect the geological structure and sedimentary environment of the target area.

[0030] In data preprocessing, the raw basic data is first cleaned to remove irrelevant, erroneous, and incomplete data. Then, redundant information and duplicate records are identified and filtered to ensure data accuracy and consistency. The cleaned and filtered basic data not only reduces interference factors in the analysis process but also significantly improves the efficiency and reliability of geological feature identification.

[0031] Next, the cleaned data is classified based on its content and relevance to geological features, into two datasets: a geological background feature dataset and a geological structural feature dataset. The geological background feature dataset mainly covers the stratigraphic sedimentary environment, lithological assemblage, and geological evolution information within the region; the geological structural feature dataset includes fault development, tectonic deformation patterns, and related tectonic activity data. This classification method facilitates targeted feature analysis and can more accurately reveal the geological characteristics of the target area.

[0032] For the categorized datasets, this invention employs a specialized geological feature identification method to analyze each type of geological feature. The geological background feature dataset provides a comprehensive understanding of the sedimentary environment and geological history of the target area, offering reliable background support for subsequent assessment of oil and gas preservation status. The geological structural feature dataset, on the other hand, details the distribution of faults, the degree of fracture development, and the intensity of tectonic deformation, providing crucial structural control factors for evaluating oil and gas preservation conditions.

[0033] Based on the present invention, preprocessing steps such as data cleaning and filtering of redundant and duplicate data effectively eliminate noisy data, improving data accuracy and consistency and ensuring the reliability of subsequent analysis. Classifying the basic data based on geological feature types allows for independent analysis of geological background and structural features, ensuring the relevance and comprehensiveness of the analysis. Applying a specialized feature recognition method to the classified dataset significantly improves the efficiency and accuracy of geological feature identification, laying a solid foundation for subsequent evaluation of oil and gas preservation conditions. This method can accurately identify the geological features of the target area, providing a scientific basis for oil and gas exploration and development, and has significant guiding significance, especially in the evaluation of oil and gas preservation conditions in complex geological structures.

[0034] Step S20: Collect logging data of the target area and perform oil and gas preservation status identification based on the logging data.

[0035] Specifically, based on the logging data of the target area, data clustering is performed to obtain multiple datasets; data preprocessing is performed on each dataset to obtain a normalized dataset, which is used as identification data; and oil and gas preservation status identification is performed based on the identification data.

[0036] In this embodiment of the invention, well logging data from the target area is collected to construct a comprehensive dataset. Due to the large volume and diverse types of well logging data, clustering is performed on the data to ensure analytical efficiency and result accuracy. Based on a similarity algorithm, the well logging data is clustered into multiple datasets, each containing well logging curves or parameter values ​​with similar physical properties. This data clustering process not only reduces data complexity but also facilitates targeted analysis of geological features with different attributes.

[0037] After obtaining multiple datasets, data preprocessing is performed to improve data quality and consistency. Specifically, noise, outliers, and missing values ​​in the well logging data are cleaned and imputed, and the data is normalized to a numerical range of the same scale to make different datasets comparable. This step generates a standardized identification dataset, providing a unified analytical basis for subsequent oil and gas conservation status identification.

[0038] Next, the hydrocarbon preservation status is identified based on the normalized identification dataset. The identification process combines multiple logging parameters (such as the probability of hydrocarbon reservoirs corresponding to abnormally high resistivity values, and the correlation between low density and high reservoir porosity) to construct a comprehensive evaluation model. This model can effectively identify the hydrocarbon-bearing characteristics of formations and analyze the fluid distribution and preservation status of formations by combining the changing trends of logging curves. The identification results can classify the hydrocarbon preservation conditions of the target area, for example, dividing it into favorable preservation areas, general preservation areas, and unfavorable preservation areas.

[0039] Step S30: Identify key evaluation indicators based on geological characteristics and oil and gas preservation status.

[0040] Specifically, based on the oil and gas preservation status identification results, the sensitivity of each dataset to the impact of oil and gas preservation status is determined; the N datasets with the highest sensitivity are selected as sensitive datasets; and the corresponding key evaluation indicators are determined based on the sensitive datasets.

[0041] Furthermore, the step of determining the sensitivity of each dataset to the impact of the oil and gas preservation status based on the oil and gas preservation status identification results includes: calculating the contribution value of each dataset to the oil and gas preservation status based on the oil and gas preservation status identification results; performing normalization processing on the contribution value of each dataset to generate the corresponding sensitivity of the impact of each dataset.

[0042] Specifically, the key evaluation indicators include any one or more of the following: exposed strata, distance from the main controlling fault, degree of fault development, and chemical characteristics of formation water.

[0043] In this embodiment of the invention, an initial dataset is generated by analyzing the geological features and identifying the hydrocarbon preservation status of the target area. Geological features include basic information such as fault distribution, sedimentary structures, and stratigraphic exposures. The hydrocarbon preservation status identification integrates well logging data, seismic data, and exploration results to assess the preservation status of the target area. Based on this data, a multidimensional dataset is constructed, covering various factors affecting hydrocarbon preservation conditions.

[0044] Next, by assessing the sensitivity of each dataset to the oil and gas preservation status, datasets with significant impact on preservation status are selected. Specifically, based on the oil and gas preservation status identification results, the contribution value of each dataset to the oil and gas preservation status is calculated, reflecting the strength of the influence of different parameters in the dataset on changes in preservation status. For example, the degree of fault development may play a major role in the risk of oil and gas loss, while the chemical characteristics of formation water may be an important factor in oil and gas accumulation conditions. By calculating the contribution value of each dataset and performing normalization, the influence of each dataset is quantified into a sensitivity index, generating a clear sensitivity ranking.

[0045] The top N datasets in terms of sensitivity were extracted as the sensitive datasets, representing the set of parameters that have the greatest impact on oil and gas preservation status. Based on the sensitive datasets, corresponding key evaluation indicators were determined. These indicators directly reflect the core factors affecting oil and gas preservation status, including but not limited to the following: 1) Exposed strata: The exposure of strata directly affects the weathering and erosion of underground reservoirs. Newer strata exposure usually indicates better preservation conditions.

[0046] 2) Distance from the main controlling fault: Areas farther away from the main controlling fault are often less affected by tectonic activity and have more favorable preservation conditions.

[0047] 3) Degree of fracture development: The density of fractures, the fault displacement, and the number of strata cut through them determine the tectonic stability of the region. High degree of fracture development usually leads to an increased risk of oil and gas loss.

[0048] 4) Chemical characteristics of formation water: Formation water with high mineralization and mainly CaCl2 type usually indicates good oil and gas preservation conditions.

[0049] Through screening and identification, key evaluation indicators were extracted by the system. These indicators can be further used to construct an evaluation model for oil and gas preservation conditions, and to classify the target area into preservation-favorable areas, general areas, and unfavorable areas.

[0050] In one possible implementation, the exposure of surface strata is closely related to oil and gas preservation conditions. Strata exposure serves as a crucial basis for assessing preservation conditions. Newer exposed strata indicate less damage from weathering and erosion, more complete underground strata preservation, and a higher probability of high-quality reservoirs. Concentrated bitumen in the rocks suggests the existence of ancient oil reservoirs, which have been completely or largely destroyed in geological history or in modern times. In oil-bearing areas, as burial depth increases, the vertical profile of the oilfield sequentially exhibits Na₂SO₄ or MgCl₂, NaHCO₃, and CaCl₂ types from top to bottom. Surface water or exposed groundwater is generally Na₂SO₄ type, while CaCl₂ type is distributed deep within the crust, isolated from the surface atmosphere and precipitation. In the upper section of the oilfield profile, NaHCO₃ type dominates, transitioning to MgCl₂ type with increasing burial depth, and finally becoming CaCl₂ type. The overall oil and gas preservation situation is evaluated based on the above data.

[0051] Based on this invention, key evaluation indicators are automatically screened through sensitivity analysis, avoiding the subjectivity of parameter selection in traditional oil and gas preservation condition analysis, making the evaluation process more scientific and comprehensive. Sensitive datasets are selected by sensitivity ranking, focusing the analysis on factors that significantly affect preservation status, greatly reducing interference from irrelevant or secondary data and improving evaluation efficiency. The extraction and normalization of key evaluation indicators ensure that the factors influencing oil and gas preservation status are accurately quantified, providing a reliable basis for subsequent evaluation and zoning. This method is applicable to various geological conditions, especially for structurally complex areas, and can dynamically adjust analysis parameters and indicator extraction schemes, making the method more universal. By accurately identifying the correlation between geological features and preservation status, the generated key evaluation indicators provide clear guidance for oil and gas exploration and preservation condition evaluation, assisting in the optimization of development plans.

[0052] Step S40: Based on the logging data of the target area, assign values ​​to each key evaluation index, and evaluate the oil and gas preservation conditions based on the assigned key evaluation indexes.

[0053] Specifically, based on the logging data of the target area, the data information required for each key evaluation indicator is extracted; based on each key evaluation indicator, the corresponding assignment rules are called, and based on the extracted data information, the corresponding assignment rules are executed to obtain the assignment of each key evaluation indicator.

[0054] Furthermore, the scoring rules for exposed strata are based on their age, with older strata receiving lower scores; the scoring rules for the distance from the main controlling fault are based on the range of well-to-fault distances, with larger ranges receiving higher scores; the scoring rules for the degree of fault development are based on the degree of fault development, with lower degrees receiving lower scores; and the scoring rules for the chemical characteristics of formation water are based on the range of mineralization and water type, with higher scores assigned to water types with higher mineralization and CaCl2 as the main water type, and lower scores assigned to water types with lower mineralization and NaSO4 or MgCl2 as the main water type.

[0055] Furthermore, the evaluation of oil and gas conservation conditions is performed based on the assigned key evaluation indicators, including: adding preset weights to the assigned key evaluation indicators, and performing a weighted summation operation after weighting to obtain the corresponding oil and gas conservation condition evaluation score for the target area; and performing corresponding evaluation level matching in the evaluation library based on the oil and gas conservation condition evaluation score of the target area as the evaluation result output.

[0056] In this embodiment of the invention, data information required for each key evaluation indicator is extracted from well logging data of the target area. Well logging data reflects the physical and chemical properties of the subsurface strata, including resistivity, natural gamma ray, density, sonic transit time, and the chemical composition of formation water. This data forms the basis for assigning values ​​to the key evaluation indicators. Through in-depth analysis of well logging curves and related parameters, geological information related to the evaluation indicators can be accurately extracted, such as stratum age, distance from the well to the main controlling fault, fault development degree, and formation water salinity and water type. After obtaining the basic data information, quantitative values ​​are assigned according to the corresponding assignment rules for each key evaluation indicator. 1) Assignment rules for exposed strata: Assign values ​​to exposed strata in the region based on their age. Newer strata are usually less affected by weathering and erosion and have better preservation conditions, so they are assigned higher scores; while older strata may have undergone severe damage due to long-term exposure, so they are assigned relatively lower scores.

[0057] 2) Distance from the main controlling fault assignment rule: Based on the distance of the well from the main controlling fault, the larger the range, the less affected by the fault activity, and the more favorable the oil and gas preservation conditions, and the higher the assignment; conversely, the smaller the range, the lower the assignment.

[0058] 3) Fault development degree assignment rules: The assignment is based on the fault density, fault displacement, and number of layers cut through. Areas with low fault development degree have better structural stability and preservation conditions, and therefore are assigned higher values; while areas with high fault development degree are usually accompanied by the risk of hydrocarbon loss, and are assigned lower values.

[0059] 4) Formation water chemical characteristics assignment rules: The assignment is based on a combination of salinity and water type. Formation water with higher salinity and CaCl2 as the main water type indicates better preservation conditions and is therefore assigned a higher score; while formation water with lower salinity or Na2SO4 or MgCl2 as the main water type may reflect poorer preservation conditions and is assigned a lower score.

[0060] After assigning values, the oil and gas preservation conditions are evaluated based on the assigned key evaluation indicators. Preset weights are assigned to each key evaluation indicator, with the weights set according to the relative importance of the indicator's impact on oil and gas preservation conditions. For example, the degree of fault development and formation water chemistry characteristics are usually core factors determining oil and gas preservation conditions, and are assigned higher weights, while the weights of exposed strata and distance from the main controlling fault are relatively lower. Based on the assigned indicators and their corresponding weights, a weighted summation operation is performed to obtain the oil and gas preservation condition evaluation score for the target area. The evaluation score is then matched with the preservation condition levels in the evaluation database. The evaluation database contains evaluation levels corresponding to different score ranges (such as favorable preservation areas, general areas, and unfavorable areas). Based on the matching results, the oil and gas preservation condition evaluation level for the target area is output.

[0061] In one possible implementation, by combining data from typical gas reservoirs and summarizing the characteristics of favorable exploration areas from already operational gas reservoirs, a set of features can be derived. Based on the results of exploration and development of typical gas reservoirs, a focused analysis of typical gas-bearing systems is conducted to determine their respective structural characteristics, source rock characteristics, reservoir characteristics, and key factors controlling hydrocarbon accumulation, guiding subsequent development of favorable zones. Formation pressure coefficients are calculated to determine if formation pressure is abnormal. Abnormally high pressure is an important driving force for oil and gas migration and accumulation, but excessively high abnormal pressure will disrupt the balance of the oil and gas accumulation environment. Abnormally low pressure is caused by factors such as decreased formation temperature, formation uplift and erosion of overlying strata, diffusion of light hydrocarbons, fluid density differences, or low water levels. Typical well gas-water shows can serve as clues for finding underground oil and gas resources. Combining the above data with the overall oil and gas preservation situation, suitable oil and gas preservation condition evaluation parameters can be selected to systematically evaluate the preservation conditions of thrust-nappe zones and their surrounding areas.

[0062] Based on this invention, the method quantifies the core influencing factors of geological conditions using well logging data. The scientific and detailed assignment rules ensure the accurate extraction and quantitative analysis of key evaluation indicators. The weight settings reflect the importance of different indicators to oil and gas preservation conditions and can be dynamically adjusted according to actual conditions, ensuring the adaptability and accuracy of the evaluation model. From data extraction and assignment to weighted summation and final evaluation level matching, the entire process is highly efficient and automated, significantly improving evaluation efficiency. This method is particularly suitable for areas with complex geological conditions and variable preservation states. By flexibly adjusting the assignment rules and weight parameters, it can be widely applied in different geological environments. The evaluation results can clearly delineate the oil and gas preservation conditions of the target area, providing clear guidance for exploration and development. For example, areas with favorable preservation can be prioritized for exploration, improving resource utilization efficiency and reducing exploration costs.

[0063] Example: like Figure 2 As shown, Figure 2 A flowchart of a specific embodiment of the method for evaluating oil and gas preservation conditions provided by the present invention.

[0064] Step 1: Combine regional geological data and production data to understand the geological background and structural characteristics of the area to be studied.

[0065] Step 2: Use earthquake, drilling and other data to study fault development, formation water type and mineralization, surface strata exposure, asphalt and ancient oil reservoir distribution, and clarify the overall situation of oil and gas preservation conditions.

[0066] Step 3: Combining data such as typical gas reservoirs, typical well gas-water shows, and pressure coefficients, select suitable oil and gas preservation condition evaluation parameters to systematically evaluate the preservation conditions of the thrust-overlap zone and its periphery.

[0067] In a specific embodiment of the invention, based on the degree of fracture development (e.g.) Figure 3 ), distance from the main control fracture (as shown in Table 1, Figure 4 ), exposed strata (such as Figure 5 ), asphalt distribution (e.g.) Figure 6 Multiple parameters, such as the chemical characteristics of formation water (as shown in Table 2), serve as key parameters for evaluating the preservation of oil and gas around the Longmenshan fault zone. These evaluation parameters comprehensively assess the oil and gas preservation conditions, and the study area of ​​the specific implementation example can be divided into three regions: a favorable preservation area, a general preservation area, and a unfavorable preservation area (as shown in Table 3).

[0068] Table 1 Distance from the main control fracture

[0069] Table 2 Chemical characteristics of formation water well name Mineralization (g / l) Water type Layer River 1 39.3 CaCl2 Feixian Pass Group L651 52.8 CaCl2 Shaxi Temple Group Fog 1 9.09 NaHCO3 Xujiahe Group Jin Shen 1 18.63 CaCl2 Shaxi Temple Group Sichuan Duck 35 51.91 CaCl2 Xujiahe Group Dayi 1 3.74 CaCl2 Xujiahe Group Table 3 Rules for dividing areas into favorable, moderately preserved, and unfavorable preservation zones

[0070] Evaluation results indicate that areas with a distance greater than 5 km from the main controlling fault, characterized by low fault development, few faults, small fault displacements, few intersecting strata, relatively young exposed strata, formation water salinity greater than 15 g / L, and water type dominated by CaCl2, are considered favorable preservation zones. Areas with a distance between 2-5 km from the main controlling fault, characterized by moderate fault development, widespread fault distribution, moderate fault displacements, numerous intersecting strata, medium exposed strata age, formation water salinity between 10-15 g / L, and formation water type dominated by NaHCO3, are considered average preservation zones. Areas with a distance less than 2 km from the main controlling fault, characterized by high fault development, widespread fault distribution, large fault displacements, numerous intersecting strata, deep incision, relatively old exposed strata, formation water salinity less than 5 g / L, and formation water type dominated by Na2SO4 and MgCl2, are considered unfavorable preservation zones. Specific examples of hydrocarbon preservation conditions are as follows... Figure 7 As shown.

[0071] Figure 8 This is a system structure diagram of an evaluation system for oil and gas conservation conditions around a thrust-nap zone provided in one embodiment of the present invention. Figure 8 As shown, this invention provides a system for evaluating oil and gas preservation conditions around a thrust-nappe zone. The system includes: a geological identification unit for collecting basic data of a target area and identifying geological features based on the basic data; a state identification unit for collecting well logging data of the target area and performing oil and gas preservation state identification based on the well logging data; an index identification unit for identifying key evaluation indicators based on geological features and oil and gas preservation state; and an evaluation unit for assigning values ​​to each key evaluation indicator based on the well logging data of the target area and performing oil and gas preservation condition evaluation based on the assigned key evaluation indicators. A third aspect of the present invention provides a computer-readable storage medium storing instructions that, when executed on a computer, cause the computer to perform the above-described method for evaluating the oil and gas preservation conditions around the thrust-overlap zone.

[0072] A fourth aspect of the present invention provides an electronic device, the electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described method for evaluating the oil and gas preservation conditions around the thrust-nap zone.

[0073] The fifth aspect of the present invention provides a computer program product, including a computer program that, when executed by a processor, implements the above-described method for evaluating the oil and gas preservation conditions around the thrust-overlap zone.

[0074] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a microcontroller, chip, or processor to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0075] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details described above. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention. It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not further describe the various possible combinations.

[0076] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the embodiments of the present invention, they should also be regarded as the content disclosed by the embodiments of the present invention.

Claims

1. A method for evaluating the oil and gas preservation conditions around a thrust-nap zone, characterized in that, The method includes: Collect basic data of the target area and identify geological features based on the basic data; Collect logging data of the target area and perform oil and gas preservation status identification based on the logging data; Key evaluation indicators are identified based on geological characteristics and oil and gas preservation status. Based on the logging data of the target area, values ​​are assigned to each key evaluation index, and oil and gas preservation conditions are evaluated based on the assigned key evaluation indexes.

2. The method according to claim 1, characterized in that, The basic data for the target area includes: Geological data and / or production data; The identification of geological features based on the aforementioned basic data includes: Data preprocessing is performed on the basic data, and the preprocessed basic data is classified based on geological feature type to obtain the dataset corresponding to the geological feature type; Geological feature identification is performed based on the datasets corresponding to each geological feature type; among which... The geological features include geological background features and geological structural features.

3. The method according to claim 2, characterized in that, The data preprocessing performed on the basic data includes: Perform data cleaning on the basic data, and identify redundant and duplicate data after data cleaning; Redundant and duplicate data are filtered to obtain preprocessed basic data.

4. The method according to claim 1, characterized in that, The process of collecting logging data from the target area and performing oil and gas preservation status identification based on the logging data includes: Based on well logging data from the target area, data clustering is performed to obtain multiple datasets; Perform data preprocessing on each dataset to obtain a normalized dataset, which will be used as the identification data. Oil and gas preservation status is identified based on the identification data.

5. The method according to claim 1, characterized in that, The identification of key evaluation indicators based on geological characteristics and oil and gas preservation status includes: Based on the oil and gas preservation status identification results, the sensitivity of each dataset to the impact of oil and gas preservation status is determined. The N datasets ranked highest in terms of sensitivity to impact are designated as sensitive datasets. Key evaluation metrics are determined based on sensitive datasets.

6. The method according to claim 5, characterized in that, The determination of the sensitivity of each dataset to the impact of oil and gas preservation status based on the oil and gas preservation status identification results includes: Based on the oil and gas preservation status identification results, the contribution value of each dataset to the oil and gas preservation status is calculated. Normalize the contribution values ​​of each dataset to generate the corresponding sensitivity of the impact of each dataset.

7. The method according to claim 1, characterized in that, The key evaluation indicators include: Any one or more of the following: exposed strata, distance from the main controlling fault, degree of fault development, and chemical characteristics of formation water.

8. The method according to claim 7, characterized in that, The well logging data based on the target area is used to assign values ​​to various key evaluation indicators, including: Based on the logging data of the target area, extract the data information required for each key evaluation indicator; The corresponding assignment rules are invoked based on each key evaluation indicator, and the corresponding assignment rules are executed based on the extracted data information to obtain the assignment values ​​of each key evaluation indicator.

9. The method according to claim 8, characterized in that, The assignment rule for exposed strata is based on the stratigraphic age; the older the strata, the lower the assigned value. The assignment rule for the distance from the main control fracture is to assign a value based on the distance range between the well and the fracture. The larger the distance range between the well and the fracture, the higher the value is assigned. The assignment rule for the degree of fracture development is to assign a value based on the degree of fracture development; the lower the degree of fracture development, the lower the value. The scoring rules for the chemical characteristics of formation water are based on the range of mineralization and the water type. Higher scores are assigned to water with higher mineralization and CaCl2 as the main water type, while lower scores are assigned to water with lower mineralization and NaSO4 or MgCl2 as the main water type.

10. The method according to claim 1, characterized in that, The evaluation of oil and gas preservation conditions is performed based on the assigned key evaluation indicators, including: Preset weights are added to the key evaluation indicators after the values ​​are assigned, and a weighted summation operation is performed after the weights are assigned to obtain the corresponding oil and gas conservation condition evaluation score for the target area. The evaluation score of oil and gas preservation conditions in the target area is used to perform corresponding evaluation level matching in the evaluation database, and the result is output as the evaluation result.

11. A system for evaluating the oil and gas conservation conditions around a thrust-nap zone, characterized in that, The system includes: A geological identification unit is used to collect basic data of the target area and identify geological features based on the basic data; The status identification unit is used to collect logging data of the target area and perform oil and gas preservation status identification based on the logging data; The indicator identification unit is used to identify key evaluation indicators based on geological characteristics and oil and gas preservation status. The evaluation unit is used to assign values ​​to each key evaluation index based on the logging data of the target area, and to evaluate the oil and gas preservation conditions based on the assigned key evaluation indexes.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that, when executed on a computer, cause the computer to perform the method for evaluating the oil and gas preservation conditions around the thrust-nap zone as described in any one of claims 1-10.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method for evaluating the oil and gas preservation conditions around the thrust-overlap zone as described in any one of claims 1-10.

14. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the method for evaluating the oil and gas preservation conditions around the thrust-nap zone as described in any one of claims 1-10.

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