Methods and Systems for Locating Oil-Rich Layers in Continental Shale Oil Formations Based on Paleomagnetic Characteristics of Rocks

Abstract

The present invention belongs to the field of shale oil exploration technology and discloses a method for finding oil-rich strata in terrestrial shale oil layers based on the paleomagnetic characteristics of rocks. The present invention utilizes the correlation between volcanic sedimentary materials and oil and gas distribution in shale oil layers, thereby using the paleomagnetic characteristics of shale samples as the connection point between volcanic activity and organic matter enrichment, guiding the rapid and accurate positioning of organic-rich strata in shale. Since the magnetic susceptibility test does not require rock powder, only about 10 g of rock fragments are required, and about 30 samples can be tested in 1 hour, the machine hourly fee is 3,000 yuan / hour, and each sample is about 100 yuan. Therefore, the use of the method of the present invention can save a lot of time and testing costs. It is conducive to the testing of a large number of samples and is applied to the selection of organic-rich strata in the early stages of exploration.

Description

Technical Field

[0001] This invention belongs to the field of shale oil exploration technology, and in particular relates to a method and system for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks. Background Technology

[0002] Lacustrine shale refers to a type of rock with a foliated structure, formed in a lacustrine environment during geological periods, consisting of fine-grained sediments (including terrigenous clastics and authigenic carbonate minerals) with a grain size of less than 62.5 μm. Shale oil, on the other hand, refers to petroleum resources contained within shale formations.

[0003] Shale oil resources enriched in lacustrine shale formations are developed in numerous oil and gas basins of different periods in my country, exhibiting characteristics such as wide distribution, large total thickness, high organic matter content, and rich brittle minerals, meeting international evaluation standards for high-quality shale oil. However, due to the strong heterogeneity of lithology and hydrocarbon distribution inherent in continental sedimentary rocks, this type of shale oil, when applied using exploration and development techniques based on North American shale oil, exhibits rapid production decline, low recovery rate, and poor development efficiency. Notably, volcanic-hydrothermal sediments are found in many shale oil layers developed under extensional geological settings in my country, and these sediments show a clear coupling relationship with organic matter enrichment. Therefore, a shale oil exploration method based on the characteristics of shale oil in my country can be established.

[0004] Currently, the main method for determining organic-rich layers in shale oil is the total organic carbon (TOC) test. This indicator directly reveals the degree of organic matter enrichment in shale layers and is the most important parameter in the early exploration and evaluation of shale oil. However, this experiment requires grinding the shale sample into powder before testing it using a carbon-sulfur analyzer or rock pyrolysis apparatus, which has the disadvantages of a relatively long testing cycle and high cost.

[0005] Based on the above analysis, the problems and shortcomings of the existing technology are as follows:

[0006] Continental shale oil layers exhibit strong heterogeneity in both lithology and oil-bearing properties, necessitating precise and rapid layer delineation and location. Furthermore, current methods for identifying organic-rich layers in shale oil primarily rely on total organic carbon (TOC) testing. This indicator directly reveals the degree of organic matter enrichment in shale layers and is the most crucial parameter in early-stage shale oil exploration and evaluation. However, this experiment requires grinding the shale sample into powder before testing using a carbon-sulfur analyzer or rock pyrolysis apparatus, resulting in a relatively long testing cycle and high costs. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a method for locating oil-rich strata in continental shale oil reservoirs based on paleomagnetic characteristics of rocks.

[0008] This invention is implemented as follows: A method for locating oil-rich strata in continental shale oil formations based on paleomagnetic characteristics of rocks includes:

[0009] Step 1: Collect and investigate geological background data;

[0010] The geological background data mainly includes regional tectonic setting and sedimentary evolution characteristics; if the shale being studied is formed in an oil and gas basin with an extensional tectonic setting, then this invention is applicable.

[0011] Step 2: Partial sample collection, processing, and paleomagnetic and total organic carbon testing;

[0012] Step 3: Microscopic identification of rock and mineral characteristics;

[0013] Step 4: Test data analysis;

[0014] Step 5: Conduct extensive and detailed testing to establish paleomagnetic profiles and accurately locate organic-rich shale oil layers.

[0015] Furthermore, the sample collection, processing, paleomagnetic analysis, and total organic carbon testing were performed on some of the samples:

[0016] A core sample of approximately 1 meter long from a shale oil reservoir was selected for detailed observation, collection, and testing. The specific steps included:

[0017] ① Observe the core samples and divide the visible lithological changes into smaller layers;

[0018] ② First, cut a core slice 2 cm long, 1 cm wide and 2 cm thick; then cut the sample in half vertically, one half to make an electron probe thin section; the other half is cut in half, one half is ground into 200 mesh rock powder, and the other half is used to test the magnetic susceptibility.

[0019] ③ Test the total organic carbon content of a portion of the powder using a carbon-sulfur analyzer; keep the remaining powder for later use.

[0020] ④ Establish a longitudinal numerical correlation curve between magnetic susceptibility and TOC.

[0021] Furthermore, the microscopic identification of the rock and mineral characteristics:

[0022] ① For inflection point samples, prepare electron probe microanalysis sections to observe the main mineral crystal morphology characteristics, such as chicken bone-shaped volcanic glass, angular quartz, and feldspar with step-like ends.

[0023] ②The remaining powder from the inflection point sample in step two is tested for its mineral composition by X-ray diffraction, mainly to observe whether the clay is mainly composed of montmorillonite;

[0024] ③ If the above observations are visible, then the inflection point is considered to be affected by volcanic activity.

[0025] Furthermore, the test data was analyzed as follows:

[0026] ① Create curves showing the changes in TOC and magnetic susceptibility values ​​along the longitudinal direction of the observed core profile, observe whether the two have the same trend, and preliminarily determine whether the linear relationship holds;

[0027] ②If true, continue to use the results of step four to exclude some data points, namely those points that do not contain volcanic material but exhibit abnormally high magnetic susceptibility;

[0028] ③ Perform correlation analysis on all correlation values ​​to determine the correlation parameters between the two and observe whether there is a threshold.

[0029] ④ Determine the effective magnetic susceptibility range using the effective TOC value and correlation relationship.

[0030] Another objective of this invention is to provide a system for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks, comprising:

[0031] The data collection module is used to collect and investigate geological background data, which mainly includes regional tectonic background and sedimentary evolution characteristics. This invention is applicable if the shale being studied is formed in an oil and gas basin within an extensional tectonic setting.

[0032] The testing module is used for partial sample collection, processing, and paleomagnetic and total organic carbon testing.

[0033] The identification module is used for the microscopic identification of rock and mineral characteristics;

[0034] The analysis module is used for test data analysis;

[0035] The positioning module is used for large-scale detailed testing, establishing paleomagnetic profiles, and accurately locating organic-rich shale oil layers.

[0036] Another object of the present invention is to provide a computer device comprising a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks.

[0037] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks.

[0038] Another objective of this invention is to provide an information data processing terminal for realizing the system of finding oil-rich strata in continental shale oil layers based on the paleomagnetic characteristics of rocks.

[0039] First, the current method for determining organic-rich layers in shale formations mainly relies on total organic carbon (TOC) testing. This method is time-consuming and expensive. For example, the commonly used method involves testing with a carbon-sulfur analyzer or a rock pyrolysis apparatus, which requires grinding the rock sample into powder before testing. Each sample costs approximately 350 yuan, and about 12 samples can be tested per hour.

[0040] Since magnetic susceptibility testing does not require rock powder, only about 10 g of rock fragments are needed, and approximately 30 samples can be tested per hour. The machine time cost is 3000 yuan per hour, and each sample costs about 100 yuan. Therefore, using the method of this invention can save a significant amount of time and testing costs. It is beneficial for conducting tests on a large number of samples and can be applied to the selection of organic-rich strata in the early stages of exploration.

[0041] Secondly, as supplementary evidence of the inventive step of the claims of this invention, it is also reflected in the following important aspects:

[0042] The expected benefits and commercial value of the technical solution of this invention after transformation are as follows:

[0043] This invention transforms the traditional method of using whole-rock organic carbon (TOC) content in shale as a key evaluation indicator for finding high-quality shale oil reservoirs into using the magnetic susceptibility of shale as the evaluation indicator. This method effectively reduces time and economic costs. For example, taking the testing of a 1 m shale core as an example, with a standard of testing one sample every 2 cm, a total of 50 samples need to be tested. Using the traditional TOC testing method would cost approximately 17,500 yuan (350 yuan / sample * 50), with sample crushing taking approximately 12.5 hours (approximately 15 minutes per sample) and TOC testing taking approximately 4.2 hours (approximately 5 minutes per sample). Using this method, the cost would be 5,000 yuan (100 yuan per sample) and 1.6 hours (approximately 2 minutes per sample). Although this method requires an initial investment of approximately 6,000 yuan for rock and mineral verification (taking 10 samples as an example, 3,000 yuan for electron probe microanalysis and observation, and 3,000 yuan for X-ray diffraction), this verification process is unnecessary when conducting large-scale sample testing later. Therefore, this solution significantly saves economic and time costs, and the cost savings will accumulate during the subsequent large-scale sample testing, demonstrating significant commercial value.

[0044] (2) Whether the technical solution of the present invention solves the technical problem that people have long wanted to solve but have never been able to solve successfully:

[0045] The relationship between volcanic activity and the enrichment of organic matter in shale formations has become a consensus in the field of scientific research. However, the problem of how to translate this scientific discovery into practical applications for oil and gas production remains unresolved. Furthermore, current oil and gas exploration and development primarily rely on geophysical methods such as well logging and seismic analysis, which differs significantly from scientific research based on geochemistry, petrology, and mineralogy. The core of this invention is to use geomagnetism, a geophysical method, as a bridge to connect scientific discovery with production practice, thereby solving the long-standing problem of disconnect between production, academia, and research in this field. Attached Figure Description

[0046] Figure 1 This is a flowchart of a method for finding oil-rich layers in continental shale oil reservoirs based on paleomagnetic characteristics of rocks, provided in an embodiment of the present invention.

[0047] Figure 2 This is a detailed flowchart of a method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks, provided in an embodiment of the present invention.

[0048] Figure 3 This is a structural block diagram of the system for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks, provided by an embodiment of the present invention.

[0049] Figure 4These are sample cores, micrographs, and corresponding curves showing the changes in magnetic susceptibility and total organic carbon (TOC) provided in the embodiments of this invention. A & B. Laminated tuffaceous dolomite. Volcanic debris is mainly composed of chicken-bone shaped and angular glassy fragments (white particles in A), completely extinct under orthogonal microscopy (black particles in B). C & D. Dolomitic tuff. Clastic material is mainly composed of chicken-bone shaped glassy fragments (white particles in C, completely extinct in D) and angular felsic fragments (first-order gray-white interference-colored particles in D). E & F. Shale containing felsic fragments (white particles). G & H. Micritic dolomite. No obvious felsic fragments observed. I. Shale mainly composed of mud-sized particles, containing a small amount of silty feldspar and quartz particles and a small amount of organic debris (black). J. The felsic mud-sized to silty particles in the shale are mostly angular. Pores are rich in organic matter (black) and pyrite (white). A, C, E, and G are single-polarized light photomicrographs; B, D, F, and H are corresponding crossed-polarized light photomicrographs; I and J are electron probe backscattered electron micrographs. K. Photographs of borehole cores containing obvious volcanic debris and their magnetic susceptibility and TOC variation curves. Lenticular tuffaceous dolomite (yellowish-brown) and dolomitic tuff (grayish-green with obvious clastic structure) are mostly interbedded in soft deformation from the same sedimentary sediments, with local interbedded small amounts of shale layers (dark gray to black lamellar). The red boxes indicate the sampling locations for magnetic susceptibility and TOC testing. L. Photographs of borehole cores without obvious volcanic debris and their magnetic susceptibility and TOC variation curves. Detailed Implementation

[0050] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0051] like Figure 1 , 2 As shown in the figure, a method for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks, provided by an embodiment of the present invention, includes the following steps:

[0052] S101, collecting and investigating geological background data;

[0053] The geological background data mainly includes regional tectonic setting and sedimentary evolution characteristics; if the shale being studied is formed in an oil and gas basin with an extensional tectonic setting, then this invention is applicable.

[0054] S102, partial sample collection, processing, paleomagnetic and total organic carbon testing;

[0055] S103, Microscopic identification of rock and mineral characteristics;

[0056] S104, Test Data Analysis;

[0057] S105, extensive and detailed testing, established paleomagnetic profiles, and accurately located organic-rich shale oil layers.

[0058] This invention provides a method for locating oil-rich strata in continental shale oil formations based on paleomagnetic characteristics of rocks. By analyzing paleomagnetic features and organic matter content, it accurately locates organic-rich shale oil strata. The specific working principle is as follows:

[0059] First, in step S101, geological background data of the area is collected and investigated. This step analyzes the tectonic setting and sedimentary evolution characteristics of the target area to determine whether the exploration of shale oil layers in the area is suitable for this invention. If the shale in the study area was formed in an oil and gas basin with an extensional tectonic setting, it indicates that the enrichment of shale oil in the area may have been influenced by volcanic activity, thus making it suitable for further paleomagnetic analysis and subsequently for finding favorable strata.

[0060] Next, the process proceeds to step S102, which involves sample collection, processing, and paleomagnetic and total organic carbon (TOC) testing. This process requires collecting shale samples within the target area, particularly samples obtained from different strata, to ensure sample representativeness. The collected samples undergo pretreatment to remove impurities and stabilize their properties. Subsequently, the paleomagnetic characteristics and TOC content of the samples are determined using specialized equipment. Paleomagnetic data reflects the geomagnetic field characteristics during the sedimentary period, thus indicating the intensity of volcanic activity, while TOC content is one of the important indicators of shale oil enrichment.

[0061] In step S103, microscopic identification of rock and mineral characteristics is performed. Through rock and mineral analysis, different mineral compositions and structural features in shale samples with paleomagnetic anomalies (high or low values) are identified, and the genesis and sedimentary environment of the shale are assessed at the microscopic level to determine whether they are related to volcanic activity.

[0062] Step S104 involves a detailed analysis of the aforementioned test data. By combining paleomagnetic data with the trend of TOC content changes, the distribution pattern of organic-rich strata in the shale is determined in the paleomagnetic data. The variation of paleomagnetic characteristics with strata, and the fluctuation characteristics of TOC content at different strata, are observed to establish a preliminary correspondence between paleomagnetic profiles and organic-rich strata characteristics.

[0063] In step S105, based on the preliminary analysis results, extensive detailed testing is conducted to establish a paleomagnetic profile, and then the organic-rich strata in the shale are located using paleomagnetic characteristics. This step refines the profile information by increasing sampling density and measurement frequency, further improving the accuracy of locating shale oil-rich strata. Detailed testing also enhances the applicability of the model, making it applicable to a wider range of areas.

[0064] Finally, by establishing paleomagnetic profiles, the organic-rich strata of shale oil were precisely located. Based on the aforementioned geological background, microscopic identification, paleomagnetic data, and TOC analysis results, the location of the shale oil-rich strata was ultimately determined.

[0065] The present invention provides partial sample collection, processing, paleomagnetic and total organic carbon testing methods:

[0066] This step involves randomly selecting a shale oil reservoir core sample of approximately 1 meter in length for detailed observation, collection, and testing. Specifically, it includes the following steps:

[0067] ① Observe the core sample and divide the visible lithological changes (color, composition, bedding) into smaller layers;

[0068] ② First, cut a core slice 2 cm long, 1 cm wide (if the thickness of the small layer is less than 1 cm, the thickness of the layer shall be used as the standard) and 2 cm thick; then cut the sample in half vertically, one half to make an electron probe thin section; the other half is cut in half equally, one half is ground into 200 mesh rock powder, and the other half is used to test the magnetic susceptibility.

[0069] ③ Test the total organic carbon (TOC) content of a portion of the powder using a carbon-sulfur analyzer; keep the remaining powder for later use.

[0070] ④ Establish a longitudinal numerical correlation curve between magnetic susceptibility and TOC.

[0071] Microscopic identification of rock and mineral characteristics provided by embodiments of the present invention:

[0072] This step mainly involves conducting ultramicroscopic morphological observations and X-ray diffraction mineral composition tests on samples exhibiting anomalous inflection points (maximum and minimum values) in the magnetic susceptibility curve. From a mineralogical perspective, this involves jointly constraining and bidirectionally verifying the intensity of volcanic activity reflected by the magnetic susceptibility characteristics. Specifically, it includes the following steps:

[0073] ① Prepare electron probe microanalysis sections (2 cm long, 1 cm wide, 60 μm thick) for inflection point samples and observe the morphological characteristics of the main mineral crystals, such as chicken bone-shaped volcanic glass. Figure 4 AJ), angular quartz and feldspar with stepped ends;

[0074] ②The remaining powder from the inflection point sample in step two is tested for its mineral composition by X-ray diffraction, mainly to observe whether the clay is mainly composed of montmorillonite;

[0075] ③ If the above observations are visible, then the inflection point is considered to be affected by volcanic activity. Figure 4 K, L).

[0076] Analysis of test data provided in this embodiment of the invention:

[0077] Correlation and threshold induction, constructing a standard favorable numerical range

[0078] This step primarily establishes a numerical correlation between the magnetic susceptibility value and the TOC value; it specifically includes the following steps:

[0079] ① Create curves showing the changes in TOC and magnetic susceptibility values ​​along the longitudinal direction of the observed core profile, observe whether the two have the same trend, and preliminarily determine whether the linear relationship holds;

[0080] ②If true, continue to use the results of step four to exclude some data points, namely those points that do not contain volcanic material but exhibit abnormally high magnetic susceptibility;

[0081] ③ Perform correlation analysis on all correlation values ​​to determine the correlation parameters between the two and observe whether there is a threshold.

[0082] ④ Determine the effective magnetic susceptibility range using the effective TOC value and correlation relationship.

[0083] like Figure 3 As shown, an embodiment of the present invention provides a system for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks, comprising:

[0084] The data collection module is used to collect and investigate geological background data, which mainly includes regional tectonic background and sedimentary evolution characteristics. This invention is applicable if the shale being studied is formed in an oil and gas basin within an extensional tectonic setting.

[0085] The testing module is used for partial sample collection, processing, and paleomagnetic and total organic carbon testing.

[0086] The identification module is used for the microscopic identification of rock and mineral characteristics;

[0087] The analysis module is used for test data analysis;

[0088] The positioning module is used for large-scale detailed testing, establishing paleomagnetic profiles, and accurately locating organic-rich shale oil layers.

[0089] Another object of the present invention is to provide a computer device comprising a memory and a processor, the memory storing a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks.

[0090] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks.

[0091] Another objective of this invention is to provide an information data processing terminal for realizing the system of finding oil-rich strata in continental shale oil layers based on the paleomagnetic characteristics of rocks.

[0092] The system for locating oil-rich strata in continental shale oil formations based on paleomagnetic characteristics of rocks, as described in this invention, achieves efficient and accurate localization and identification of oil-rich shale oil strata through the collaborative operation of multiple modules. The detailed working principle of this system is as follows:

[0093] First, the data collection module is used to collect and investigate geological background data for the target area. This module primarily involves analyzing the regional tectonic setting and studying sedimentary evolution characteristics. Understanding the regional tectonic setting, especially if the shale formation is occurring in an extensional tectonic setting within an oil and gas basin, further clarifies the applicability of this invention. The geological background data provides directional guidance for subsequent sampling and analysis and lays the foundation for the accurate identification of oil-rich strata.

[0094] Next, the testing module conducts detailed tests and analyses on the collected samples. First, some target rock strata samples are collected on-site and sent to the laboratory for processing. The sample processing includes cleaning, cutting, and preparing standard specimens suitable for testing. Subsequently, the testing module performs paleomagnetic testing and total organic carbon (TOC) content testing on the samples. Paleomagnetic testing reveals the geomagnetic characteristics during the shale formation period, while TOC testing directly reflects the organic matter content in the samples, thus providing a preliminary assessment of the samples' oil-bearing potential. This process provides crucial data on geomagnetic characteristics and organic matter enrichment, laying the foundation for subsequent precise location of oil-rich strata.

[0095] The identification module further performs microscopic analysis of the rock and mineral characteristics of the collected samples. Through microscopic and electron microscopic observation, the module analyzes the mineral composition, structural features, and porosity of the rocks. These microscopic characteristics are crucial for determining the sedimentary environment and organic matter enrichment of shale. The identification module ensures the accuracy of the test samples, providing more detailed mineral and lithological characteristics for subsequent data analysis and stratigraphic positioning.

[0096] The analysis module is responsible for comprehensively analyzing the data obtained from testing and identification. In this module, the system combines paleomagnetic test results, TOC content, and microscopic rock and mineral characteristics to perform multi-dimensional data mining and feature correlation. Through these analyses, the system can identify geomagnetic features and organic matter enrichment patterns associated with high oil content. The analysis module utilizes data correlation analysis and statistical methods to identify key parameters and indicators that may be related to oil-rich strata, further pinpointing potential high-oil-bearing strata regions.

[0097] The localization module conducts extensive and detailed testing based on the analysis results to establish a systematic paleomagnetic profile. This module performs dense and detailed sampling and testing within the target area, mapping the paleomagnetic profiles of each sampling point, thereby accurately locating the organic-rich shale oil layers. Through this localization module, the system can effectively pinpoint oil-rich layers within a large area to specific geological strata, significantly improving the targeting and accuracy of subsequent extraction.

[0098] The present invention also provides a computer device including a memory and a processor. The memory stores a computer program, which, when executed by the processor, automatically performs the aforementioned steps of the oil-rich layer analysis and location method. This device automates data collection, processing, analysis, and result output, significantly reducing manual workload and improving analysis accuracy and processing efficiency.

[0099] Furthermore, this invention also proposes a computer-readable storage medium storing an executable computer program. When this program is loaded and executed by a processor, it can automatically complete the various steps of locating oil-rich strata based on paleomagnetic characteristics of rocks. This storage medium is suitable for various devices, such as personal computers and data analysis workstations, thereby expanding the scope of application of this invention.

[0100] Finally, the system also includes an information data processing terminal, which integrates and processes the acquired and analyzed geological and lithological data, achieving fully automated operation from data collection and analysis to result output. The information data processing terminal can update and present data analysis results in real time, facilitating researchers' dynamic monitoring and in-depth analysis of oil-bearing strata in different geological regions. This data terminal provides geologists with intelligent data support and a visual analysis interface, offering convenience and scientific basis for the identification and precise location of oil-rich strata.

[0101] Specific implementation of the present invention:

[0102] Step 1: Collect and investigate geological background data

[0103] Collect regional tectonic background data, including geological maps, seismic data, and previous research findings.

[0104] Investigate the characteristics of sedimentary evolution and analyze the sedimentary environment and history of the basin.

[0105] To determine whether the shale formation originated in an oil and gas basin within an extensional tectonic setting.

[0106] Step Two: Sample Collection, Processing, and Paleomagnetic and Total Organic Carbon Testing

[0107] A core sample of a shale oil layer approximately 1 meter long was randomly selected for drilling.

[0108] Observe the core samples, record lithological changes, and divide the rock into sublayers.

[0109] Cut a 2 cm x 1 cm x 2 cm core slice and split it in half. One half is used to make an electron probe thin section of rock; the other half is used to test the magnetic susceptibility and to grind the other half into 200 mesh rock powder.

[0110] The total organic carbon (TOC) content of the powder was tested using a carbon-sulfur analyzer.

[0111] Establish a longitudinal numerical correlation curve between magnetic susceptibility and TOC ( Figure 4 K, L).

[0112] Step 3: Microscopic Identification of Rock and Mineral Characteristics

[0113] Electron probe microanalyses were fabricated for samples with abnormal inflection points in the magnetic susceptibility curve to observe the morphological characteristics of mineral crystals.

[0114] The mineral composition of the remaining powder was determined by X-ray diffraction, with particular attention paid to the types of clay minerals.

[0115] Based on the observations, determine whether the inflection point is affected by volcanic activity.

[0116] Step 4: Test Data Analysis

[0117] Create curves showing the changes in TOC and magnetic susceptibility values ​​along the longitudinal direction of the core profile.

[0118] Analyze the curves to determine the linear relationship and eliminate outlier data points.

[0119] Perform correlation numerical analysis to determine correlation parameters and thresholds.

[0120] The effective susceptibility range is determined by using the effective TOC value and correlation relationship.

[0121] Step 5: Conduct extensive and detailed testing to establish paleomagnetic profiles and accurately locate organic-rich shale oil layers.

[0122] Establish paleomagnetic profiles and, in conjunction with geological background data, accurately locate oil and gas-rich strata using the effective magnetic susceptibility range determined in steps two through four.

[0123] Oil layer identification and location: By utilizing predictive models based on the paleomagnetic characteristics of rocks, oil-rich layers in continental shale oil reservoirs can be accurately identified, improving exploration success rates and reducing exploration costs. By analyzing paleomagnetic data of rocks, combined with geological structure and sedimentary environment information, oil layers with high oil content and great exploitation potential can be quickly and accurately located, providing a scientific basis for subsequent drilling and development.

[0124] Oil and gas resource assessment: Predictive models based on paleomagnetic characteristics of rocks can also be used for oil and gas resource assessment. Through comprehensive analysis of multiple oil-rich strata, the reserves and exploitation potential of the entire shale oil reservoir can be estimated, providing an important reference for oil companies' investment decisions.

[0125] Oil and Gas Exploration Software Development: This technical solution can be integrated into oil and gas exploration software, providing a tool for identifying oil-bearing strata based on paleomagnetic characteristics of rocks. Through the software interface, users can input multi-source data, including geological, geophysical, and geochemical data. The software automatically analyzes and predicts oil-rich strata, assisting exploration personnel in making more accurate decisions.

[0126] Oil and Gas Exploration Consulting Services: Based on this technical solution, oil and gas exploration consulting services can be provided. Professional oil and gas exploration consulting and technical support can be offered to oil companies, geological survey institutions, etc., including services such as oil-rich strata identification, drilling strategy optimization, and oil and gas resource assessment, promoting technological progress and industrial upgrading in the field of oil and gas exploration and development.

[0127] In conclusion, the method of locating oil-rich strata in continental shale oil formations based on paleomagnetic characteristics of rocks has broad application prospects and significant economic value, and can provide strong technical support for the field of petroleum exploration and development.

[0128] This invention is based on the scientific discovery of the coupling relationship between organic matter enrichment in shale and volcanic sediments. It utilizes paleomagnetic susceptibility to identify volcanic sediments in shale, thereby locating organic-rich strata. Based on the following three characteristics, magnetic susceptibility can provide preliminary identification of volcanic information in shale: ① Volcanic activity concurrently produces large amounts of dust-like magnetite, which is transported to distant sedimentary areas along with volcanic ash; ② With the improvement of modern paleomagnetic research equipment, trace amounts of magnetite information can be captured in various sedimentary rocks, generating magnetic susceptibility signals; ③ The singular origin and stability of magnetite are widely used in paleomagnetics to identify volcanic activity. To verify the effectiveness of this invention, correlation analysis of magnetic susceptibility, petrological mineralogy, and TOC characteristics of 13 standard core samples (total thickness 30 cm) has been completed. Figure 4 The coupling relationship between the two indicates that magnetic susceptibility can accurately reflect the presence and relative intensity of volcanic activity in shale, and is significantly correlated with TOC characteristics, i.e., magnetic susceptibility between 3 and 5 x 10⁻⁶. -8 m 3 When the value is / kg, the corresponding TOC value tends to increase.

[0129] It should be noted that embodiments of the present invention can be implemented in hardware, software, or a combination of both. The hardware portion can be implemented using dedicated logic; the software portion can be stored in memory and executed by a suitable instruction execution system, such as a microprocessor or dedicated design software. Those skilled in the art will understand that the above-described devices and methods can be implemented using computer-executable instructions and / or included in processor control code, for example, such code provided on a carrier medium such as a disk, CD, or DVD-ROM, a programmable memory such as read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. The devices and modules of the present invention can be implemented using hardware circuitry such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field-programmable gate arrays, programmable logic devices, etc., or using software executed by various types of processors, or using a combination of the above-described hardware circuitry and software, such as firmware.

[0130] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for locating oil-rich strata in continental shale oil formations based on paleomagnetic characteristics of rocks, characterized in that, The method for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks includes the following steps: Step 1: Collect and investigate geological background data; Geological background data includes regional tectonic setting and sedimentary evolution characteristics; if the shale was formed in an oil and gas basin in an extensional tectonic setting, then proceed with steps two through five in sequence; Step 2: Partial sample collection, processing, and paleomagnetic and total organic carbon testing; Step 3: Microscopic identification of rock and mineral characteristics; Step 4: Test data analysis; Step 5: Conduct extensive and detailed testing to establish paleomagnetic profiles and accurately locate organic-rich shale oil layers; The specific details of sample collection, processing, paleomagnetic analysis, and total organic carbon testing are as follows: A core sample of approximately 1 meter long from a shale oil reservoir was selected for detailed observation, collection, and testing. The specific steps included: ① Observe the core samples and divide the visible lithological changes into smaller layers; ② First, cut a core slice 2 cm long, 1 cm wide and 2 cm thick; then cut the sample in half vertically, one half to make an electron probe thin section; the other half is cut in half, one half is ground into 200 mesh rock powder, and the other half is used to test the magnetic susceptibility. ③ Test the total organic carbon content of a portion of the powder using a carbon-sulfur analyzer; keep the remaining powder for later use. ④ Establish a longitudinal numerical correlation curve between magnetic susceptibility and TOC; The specific analysis of the test data is as follows: ① Create curves showing the changes in TOC and magnetic susceptibility values ​​along the longitudinal direction of the observed core profile, observe whether the two have the same trend, and preliminarily determine whether the linear relationship holds; ②If this is true, continue to exclude some data points, namely those that do not contain volcanic material but exhibit abnormally high magnetic susceptibility; ③ Perform correlation analysis on all correlation values ​​to determine the correlation parameters between the two and observe whether there is a threshold. ④ Determine the effective magnetic susceptibility range using the effective TOC value and correlation relationship.

2. The method for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks as described in claim 1, characterized in that, The specific microscopic identification of rock and mineral characteristics is as follows: ① For inflection point samples, prepare electron probe microanalytes and observe the main mineral crystal morphology characteristics, including chicken bone-shaped volcanic glass, angular quartz and feldspar with stepped ends. Inflection point samples are those with abnormal inflection points in the magnetic susceptibility curve. ②The remaining powder from the inflection point sample in step two is tested for its mineral composition by X-ray diffraction to observe whether montmorillonite is the main component of its clay. ③ If the above observations are visible, then the inflection point is considered to be affected by volcanic activity.

3. A system for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics, implementing the method for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics as described in any one of claims 1-2, characterized in that, The system for locating oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks includes: The data collection module is used to collect and investigate geological background data, including regional tectonic background and sedimentary evolution characteristics. If the shale is formed in an oil and gas basin with an extensional tectonic background, the test module and the location module will be executed sequentially. The testing module is used for partial sample collection, processing, and paleomagnetic and total organic carbon testing. The identification module is used for the microscopic identification of rock and mineral characteristics; The analysis module is used for test data analysis; The positioning module is used for large-scale detailed testing, establishing paleomagnetic profiles, and accurately locating organic-rich shale oil layers.

4. A computer device, characterized in that, The computer device includes a memory and a processor. The memory stores a computer program, which, when executed by the processor, causes the processor to perform the steps of the method for finding oil-rich strata in continental shale oil layers based on paleomagnetic characteristics of rocks as described in any one of claims 1-2.

5. A computer-readable storage medium storing a computer program, which, when executed by a processor, causes the processor to perform the steps of the method for finding oil-rich layers in continental shale oil reservoirs based on paleomagnetic characteristics of rocks as described in any one of claims 1-2.

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