Uranium mine positioning method controlled by oil and gas dissipation channel

Abstract

The invention relates to the technical field of uranium mineralization prediction, in particular to a uranium ore positioning method for oil and gas dissipation channel control, which comprises the following steps: for a drilling point preliminarily meeting a uranium mineralization standard, determining whether a temperature range of a gas generation threshold meets a mineralization achievement condition or not, and transferring a preliminary drilling area according to a fluid activity path; the direction of moving the preliminary drilling area is determined, and the initial drilling parameters are adjusted; fluid property classification is carried out, and it is determined that the uranium metallogenic potential of the paleoenvironment where the sample is located meets expectation or secondary analysis of the uranium metallogenic potential is needed when the sample is formed; determining composition characteristic types of the samples, judging whether the causes of the samples are related to biological action or not according to the proportions of the samples in different composition characteristic types, and adjusting a judgment standard for determining uranium mineralization potential; and when the uranium mineralization potential meets the expectation or the cause of the sample is irrelevant to the biological action, the coexistence of the uranium ore and the hydrocarbon inclusion is verified through drilling. According to the invention, efficient uranium ore positioning is realized by identifying the oil-gas dissipation channel and the associated ore control elements.

Description

Technical Field

[0001] The present invention relates to the technical field of uranium mineralization prediction, and in particular to a uranium ore positioning method for controlling oil and gas escape channels. Background Art

[0002] Hydrocarbon fluids (CH4, H2S, etc.) act as reducing agents to reduce hexavalent uranium (U 6+ ) is reduced to tetravalent uranium (U 4+ ) form uranium minerals (such as pitchblende). Oil and gas escape pathways (faults, unconformities, permeable sand bodies, etc.) serve as pathways for oil and gas migration and can also serve as pathways for uranium-bearing fluids. Uranium ore bodies are more likely to form in areas where these two pathways overlap.

[0003] Chinese Patent Publication No.: CN104237964A discloses a method for locating paleochannel-type sandstone uranium deposits, which includes the following steps: step (1) identifying whether the geological area of ​​the uranium deposit to be located belongs to a uranium-producing paleochannel; step (2) if the geological area of ​​the uranium deposit to be located belongs to a uranium-producing paleochannel, delineating the uranium-producing paleochannel section of the area; step (3) delineating the soil radon gas anomaly area of ​​the uranium-producing paleochannel section delineated in the above step (2); step (4) superimposing the uranium-producing paleochannel section determined in the above step (2) and the soil radon anomaly area delineated in the above step (3), and the overlapping area of ​​the two is the paleochannel-type sandstone uranium mineralization favorable area, that is, the paleochannel-type sandstone uranium mineralization favorable area is located. It can be seen that the paleochannel-type sandstone uranium deposit locating method has the following problems:

[0004] Relying solely on paleo-river channels (uranium sources) and radon gas anomalies (indicators of uranium migration), without considering the reducing ability of hydrocarbon fluids, paleo-river channels alone may only provide uranium sources, but lack reducing agents (hydrocarbons / organic matter) and cannot form industrial ore bodies. Summary of the Invention

[0005] To this end, the present invention provides a uranium mine positioning method for controlling oil and gas escape channels, so as to overcome the problem that the reduction ability of hydrocarbon fluids is not considered in uranium mine positioning in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides a uranium mine positioning method for controlling oil and gas escape channels, comprising:

[0007] Identify formation faults, analyze the distribution characteristics of oil and gas reservoirs, evaluate uranium supply capacity, and obtain superimposed maps of faults and oil-bearing areas;

[0008] Determine a preliminary drilling area based on the superimposed map, drill according to preliminary drilling parameters to obtain a number of samples, determine whether the drilling point preliminarily meets the uranium formation standard based on gamma anomaly determination and sedimentary environment characteristics of the samples, and generate a preliminary uranium formation possibility evaluation value;

[0009] For drilling points that initially meet the uranium formation criteria, determine the temperature range of the oil generation threshold based on the vitrinite reflectance of the sample, determine whether the mineralization conditions are met based on the geothermal gradient and the initial drilling depth corresponding to the drilling point, and determine whether to relocate the initial drilling area based on the fluid activity path;

[0010] Determine the enrichment of Sr and Rb near the fractures based on the Sr and Rb contents in each sample, indicate the fluid flow path, and determine the direction of moving the preliminary drilling area and adjust the initial drilling parameters based on the fluid flow path and the preliminary uranium formation possibility evaluation value;

[0011] When there are several cracks in the formation fracture that meet the conditions for determining the regional movement direction, the main mineralization period fluid is defined in combination with the homogenization temperature of the inclusions, and the direction corresponding to the main mineralization period fluid is taken as the fluid movement path;

[0012] Classify the fluid properties based on the homogenization temperature and salinity of the fluid inclusions in the sample to determine whether the uranium mineralization potential of the paleoenvironment in which the sample was formed meets expectations or requires secondary analysis of uranium mineralization potential;

[0013] Isotope testing is performed on samples to determine the compositional characteristics of the samples. Based on the proportion of samples in different compositional characteristics, it is determined whether the genesis of the samples is related to biological processes, and the criteria for determining uranium mineralization potential are adjusted accordingly.

[0014] When the uranium mineralization potential is in line with expectations, or the sample genesis is not related to biological activity, drilling is used to verify the coexistence of uranium minerals and hydrocarbon inclusions.

[0015] Furthermore, the process of determining the temperature range of the oil generation threshold includes:

[0016] Detect the vitrinite reflectance of the sample. When the vitrinite reflectance is lower than the critical range, it is judged that the source rock in the area at the current depth is in a low maturity stage;

[0017] When the vitrinite reflectance is in the critical range, it is judged that the source rock in the area at the current depth is in the mature stage;

[0018] When the vitrinite reflectance exceeds the critical range, it is judged that the source rock in the area at the current depth is in a high maturity stage;

[0019] The temperature range of the oil generation threshold is determined according to the maturity stage of the source rock.

[0020] Furthermore, the mineralization condition is to trigger oil and gas escape;

[0021] determining the actual formation temperature based on the geothermal gradient of the preliminary drilling area and the initial drilling depth;

[0022] When the actual formation temperature is lower than the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature has not triggered oil and gas escape, and the initial drilling area is shifted according to the fluid activity path;

[0023] When the actual formation temperature is at the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature triggers oil and gas escape.

[0024] Further, the process of shifting the initial drilling area according to the fluid movement path includes:

[0025] Select samples that have undergone alteration and discoloration near the cracks, and perform μXRF analysis on several samples that have undergone alteration and discoloration to obtain the Sr and Rb contents in each sample;

[0026] Determine whether to move the preliminary drilling area along the rising direction or the falling direction of the formation fault according to whether the Sr / Rb ratio of the sample at the drilling point in the rising direction of the formation fault is greater than the Sr / Rb ratio of the sample at the drilling point in the falling direction of the formation fault;

[0027] After the preliminary drilling area is moved, the initial drilling depth in the initial drilling parameters is adjusted according to the height change of the formation fracture, and the initial drilling quantity is adjusted according to the preliminary uranium formation possibility evaluation value.

[0028] Furthermore, the processes that define the fluids of the main mineralization period include;

[0029] When several fractures meet the criteria for determining the regional movement direction, the fracture direction in which the homogenization temperature of the fluid inclusions in the sample is closest to the determined oil generation threshold temperature is selected as the direction corresponding to the fluid in the main mineralization period;

[0030] The condition for determining the direction of regional movement is that the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture is greater than the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture.

[0031] Further, the process of determining uranium mineralization potential includes;

[0032] If the homogenization temperature exceeds the standard temperature range and the inclusion salinity exceeds the standard salinity range, the fluid inclusions in the sample are judged to be hydrothermal fluids and the uranium mineralization potential is lower than expected;

[0033] If the homogenization temperature is lower than the standard temperature range and the inclusion salinity is lower than the standard salinity range, the fluid inclusions in the sample are judged to be shallow atmospheric water, and the uranium mineralization potential needs to be further analyzed based on the geological environment;

[0034] If the homogenization temperature is within the standard temperature range and the inclusion salinity is within the standard salinity range, the fluid inclusions in the sample are judged to be oil and gas associated fluids, and the uranium mineralization potential is in line with expectations.

[0035] Furthermore, the process of further analyzing the uranium mineralization potential includes;

[0036] The drilling samples were tested for carbon and oxygen isotopes of carbonates, and carbonates were divided into three types according to their carbon and oxygen isotope composition characteristics;

[0037] When the proportion of samples in zone II is less than the critical proportion, it is judged that the cause of the sample is not related to biological action;

[0038] When the proportion of samples in zone II is less than the critical proportion, it is judged that the origin of the samples is related to biological action, the carbon source of the samples is affected by biological action, and the judgment criteria of homogenization temperature and inclusion salinity are adjusted.

[0039] Furthermore, when uranium rocks coexist with asphalt, it is confirmed that uranium minerals and hydrocarbon inclusions coexist in the area.

[0040] Furthermore, the process of determining whether a drilling site preliminarily meets the uranium formation criteria includes:

[0041] Conduct gamma anomaly assessment on the sample to preliminarily determine whether it meets the uranium formation criteria. If it preliminarily meets the uranium formation criteria, obtain hydrocarbon biomarkers to determine whether it meets the uranium formation criteria.

[0042] The odd-even dominance index reflects the degree of thermal evolution of organic matter and determines the maturity of organic matter in the region and whether it is organic matter deposited in the modern era.

[0043] The average value of the Pr / Ph value and the gammacerane index of the sample are used to determine whether the deposition environment of the sample is a reducing environment;

[0044] The maturity of the crude oil in the region can be determined by comparing the Ts / Tm ratio with the maturity reflected by the vitrinite reflectance.

[0045] When the sedimentary environment of the sample is a reducing environment, the organic matter in the area is not organic matter deposited in modern times, and the crude oil is in a mature stage, and the sample is affected by uranium-containing oxygen-rich water after diagenesis, it is judged that the drilling point in the current preliminary drilling area corresponding to the sample has the possibility of uranium formation and preliminarily meets the uranium formation standard.

[0046] Furthermore, the process of determining whether the maturity matches is as follows:

[0047] When the maturity reflected by the vitrinite reflectance and the Ts / Tm ratio are inconsistent, the maturity stage is determined based on whether the inclusion salinity is greater than the middle value of the standard salinity range.

[0048] Compared with the prior art, the beneficial effect of the present invention is that the control of oil and gas escape channels refers to the control of uranium mineralization, which requires uranium-containing and oxygen-containing water, storage space (bottom layer structure) and redox environment (oil and gas, carbonized plant debris). In the western part of the Qaidam Basin, oil and gas coexist with uranium deposits in the same basin. Hydrocarbon fluids, as reducing agents, migrate to shallow sand bodies through channels such as faults and unconformities, undergo redox reactions with oxygen-containing and uranium-containing water, and promote uranium precipitation and enrichment. This method achieves efficient positioning of uranium deposits by identifying oil and gas escape channels and associated mineral control factors.

[0049] Furthermore, because the γ value is affected by multiple factors, it can only be used as a reference parameter to preliminarily determine the likelihood of a region containing uranium. High Pr / Ph ratios are typically found in oxidizing sedimentary environments, while lower Pr / Ph ratios are typically found under anoxic / hypersaline conditions. Reducing sedimentary environments can prevent organic matter from being oxidized, preserving it. The higher the reducibility, the greater the organic matter abundance and the greater the hydrocarbon-generating capacity. Due to the length of time required for uranium deposition to become uranium deposits, this method uses multiple parameters to preliminarily determine whether the sedimentary environment, organic matter maturity, crude oil maturity stage, and exposure to uranium-containing, oxygen-rich water at several drilling sites within the region meet the criteria for uranium mineralization.

[0050] Furthermore, vitrinite reflectance is an important tool for determining the threshold temperature for oil generation. By analyzing the reflectance variations of organic matter in rocks, the range of the threshold temperature for oil generation can be accurately determined, thereby guiding oil and gas exploration. The threshold temperature for oil generation is one of the fundamental conditions for oil and gas generation. Only when source rocks reach the threshold temperature for oil generation can they begin to generate oil in large quantities and subsequently convert it into natural gas. The threshold temperature and depth for oil generation reflect the thermal evolution history of a basin and are important indicators for analyzing the history of oil and gas generation in sedimentary basins. By determining the threshold depth and temperature for oil generation, the distribution and potential of oil and gas resources can be predicted, providing a scientific basis for oil and gas exploration.

[0051] Furthermore, vitrinite reflectance is applicable to type III (terrigenous) and type II (mixed source) organic matter, while other parameters need to be combined for type I (algae) source rocks. The Ts / Tm ratio, as an evaluation parameter, is not only related to maturity but also affected by the organic phase. Higher salinity is not conducive to the conversion of Tm to Ts, resulting in a lower Ts / Tm value. This method uses inclusion salinity to reflect paleo-salinity, corresponding to the selection of vitrinite reflectance or the maturity stage determined by the Ts / Tm ratio, thereby improving the accuracy of confirming the maturity of hydrocarbon fluids and avoiding adverse effects on subsequent analysis processes.

[0052] Furthermore, when the source rock in the current preliminary drilling area is in a low-maturity stage, this method determines that there are no oil and gas escape channels, and the preliminary drilling area needs to be moved. The fluid activity path is indicated based on the Sr content and the Rb content, and the preliminary drilling area is moved according to the fluid activity path, thereby improving the adaptability and flexibility of locating uranium deposits based on oil and gas escape channels. When there are several cracks in the formation fracture that meet the conditions for determining the regional movement direction, the main mineralization period fluid is limited in combination with the homogenization temperature of the inclusions, thereby improving the accuracy of controlling the movement of the preliminary drilling area and avoiding deviations in the movement direction.

[0053] Furthermore, fluid inclusions are diagenetic and mineralizing fluids captured and preserved in crystal defects or cavities during the growth of diagenetic minerals, recording rich original information such as pressure, temperature, and composition at the time of fluid capture. This method determines the uranium mineralization potential of the paleoenvironment in which the sample was formed by the homogenization temperature and salinity of the fluid inclusions in the sample. Hydrothermal fluids reflect the oxidizing possibility of the paleoenvironment, and the mineralization potential of uranium in this environment is low. Oil and gas associated fluids reflect that the paleoenvironment was in a reducing state with oil and gas escape, and the mineralization potential of uranium in this environment is high. Shallow atmospheric water cannot directly reflect the oxidizing nature of the paleoenvironment and requires further analysis. The uranium mineralization potential is evaluated by fluid property classification, and dual-parameter cross-validation avoids misjudgment of a single temperature indicator, limits the dynamic mineralization window, effectively defines the fluid window where oil and gas escape participates in uranium mineralization on the western margin of the Qaidam Basin, quantifies the matching between fluid properties and uranium precipitation conditions, and significantly improves the prediction accuracy of sandstone-type uranium deposit targets. This method is suitable for uranium resource evaluation in continental oil and gas basins.

[0054] Furthermore, organic acids (such as acetic acid) produced by the degradation of plant debris can complex Na + , K + Plasma reduces the apparent salinity of the fluid, and the measured value of ωNaCl may be underestimated by 5-10%; carbonaceous plant debris undergoes pyrolysis during burial, releasing organic acids and hydrocarbons, which leads to local temperature increases and causes the homogenization temperature to be artificially high; adjusting the judgment criteria of fluid properties can improve the accuracy of assessing uranium mineralization potential.

[0055] Furthermore, when carbonates fall into inorganic origin zones, it indicates that the diagenetic fluid is mainly atmospheric precipitation or deep hydrothermal fluids. Since inorganic fluids are usually poor in organic matter and lack reducing ability, they are not conducive to uranium reduction, and therefore need to rely on later hydrocarbon reduction for precipitation. This method uses carbon and oxygen isotope analysis of several samples to determine whether the area where the samples are located has the conditions where uranium is first transported by inorganic fluids and then reduced and fixed by hydrocarbons, thereby reflecting the possibility of uranium mineralization, that is, the oxidizing fluid and the reducing fluid react at the contact interface to generate insoluble uranium minerals, which work together with the upper oxidizing fluid to form an oxidation-reduction geochemical barrier, leading to the possibility of large-scale uranium enrichment and mineralization. It is determined that in inorganic-dominated areas (such as northwestern Qaidam), the exploration strategy should focus on finding evidence of organic fluid infiltration (such as hydrocarbon inclusions and carbonaceous debris) near the fault zone, which optimizes the strategic method of uranium exploration and positioning and improves the accuracy of positioning.

[0056] Furthermore, the study shows that in the western Qaidam area, uranium mineralization is mainly distributed on the periphery of the oil and gas fields on the plane; in the mineralized strata, sandstone-type uranium deposits are usually located above or in the same strata as the oil and gas strata, and this superposition relationship helps the oil and gas to transform the sandstone-type uranium deposits, thereby leading to uranium enrichment and mineralization; when selecting target areas for drilling exploration, this method delineates the target areas from three directions: structural location, stratigraphic combination and geochemical signs, reducing the workload of invalid exploration and improving the efficiency of uranium mine positioning.

[0057] Furthermore, uranium mineralization in the Yuejin-2 area is primarily distributed within gray-green sand bodies. Carbon and oxygen isotope analysis reveals that the formation of cement in the uranium-enriched areas is influenced by organic carbon. This suggests that sandstone-type uranium enrichment in this area is the result of the interaction between two fluid systems: hydrocarbon-rich basinal fluids and uranium-bearing shallow-source fluids fed from the basin margin. The location of uranium enrichment is primarily controlled by the redox interface between the upward-flowing reducing fluid and the downward-flowing oxidizing fluid.

[0058] Furthermore, through experimental analysis of carbon and oxygen isotopes, fluid inclusions, elemental geochemical characteristics, and organic geochemical characteristics, it is believed that the causal relationship between oil and gas and uranium mineralization in the western Qaidam area is mainly the following two: (1) A large amount of reducing media (carbonized plant debris) is developed in the target layer, which increases the reduction capacity of the target layer sand body and is conducive to uranium enrichment and mineralization; (2) Some target layers themselves have less reducing media, but there are major oil and gas reservoirs in the region, and the oil and gas content in the sand body is high, which not only improves the reduction properties of the sand body, but also increases the adsorption and porosity after alteration, which is conducive to uranium enrichment. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a flow chart of a uranium mine positioning method for controlling oil and gas escape channels according to an embodiment of the present invention;

[0060] Figure 2 This is a superimposed diagram of faults and oil-bearing areas in the western Qaidam area in an embodiment of the present invention;

[0061] Figure 3 is the μXRF image of the sample in the embodiment of the present invention;

[0062] Figure 4 This is a graphic illustration of the CO isotope composition in the western Qaidam region in the examples of the present invention. DETAILED DESCRIPTION

[0063] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0064] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0065] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside", and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0066] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0067] See also Figure 1-Figure 4 As shown, Figure 1 This is a flow chart of a uranium mine positioning method for controlling oil and gas escape channels according to an embodiment of the present invention; Figure 2 This is a superimposed diagram of faults and oil-bearing areas in the western Qaidam area in an embodiment of the present invention; Figure 3 is the μXRF image of the sample in the embodiment of the present invention; Figure 4 This is a graphic illustration of the CO isotope composition in the western Qaidam region in the examples of the present invention.

[0068] The present invention provides a uranium mine positioning method for controlling oil and gas escape channels, comprising:

[0069] Step S1, identifying formation faults, analyzing the distribution characteristics of oil and gas reservoirs, evaluating uranium supply capacity, and obtaining a superimposed map of faults and oil-bearing areas;

[0070] Step S2: determining a preliminary drilling area based on the superimposed map, drilling according to preliminary drilling parameters to obtain a number of samples, determining whether the drilling point preliminarily meets the uranium formation standard based on gamma anomaly determination and the sedimentary environment characteristics of the samples, and generating a preliminary uranium formation possibility evaluation value;

[0071] Step S3: For the drilling points that preliminarily meet the uranium generation criteria, determine the temperature range of the oil generation threshold based on the vitrinite reflectance of the sample, determine whether the mineralization conditions are met based on the geothermal gradient and the initial drilling depth corresponding to the drilling point, and determine whether to relocate the preliminary drilling area based on the fluid flow path;

[0072] Step S4, determining the enrichment of Sr and Rb near the fractures based on the Sr and Rb contents in each sample, indicating the fluid flow path, and determining the direction of moving the preliminary drilling area and adjusting the initial drilling parameters based on the fluid flow path and the preliminary uranium formation possibility evaluation value;

[0073] Step S5: If there are several cracks in the formation fracture that meet the regional movement direction determination conditions, the main mineralization period fluid is defined in combination with the homogenization temperature of the inclusions, and the direction corresponding to the main mineralization period fluid is used as the fluid movement path;

[0074] Step S6, classifying the fluid properties based on the homogenization temperature and salinity of the fluid inclusions in the sample to determine whether the uranium mineralization potential of the paleoenvironment in which the sample was formed meets expectations or requires secondary analysis of the uranium mineralization potential;

[0075] Step S7: performing isotope testing on the sample to determine the compositional characteristics of the sample. Based on the proportion of samples with different compositional characteristics, it is determined whether the origin of the sample is related to biological action, and the criteria for determining uranium mineralization potential are adjusted accordingly.

[0076] Step S8: When the uranium mineralization potential is in line with expectations or the sample genesis is not related to biological activity, drilling is performed to verify the coexistence of uranium minerals and hydrocarbon inclusions.

[0077] Specifically, the control of oil and gas escape channels refers to the control of uranium mineralization, which requires uranium-containing and oxygen-containing water, reservoir space (underlying structure), and a redox environment (oil, gas, and carbonized plant debris). In the western Qaidam Basin, oil and gas coexist with uranium deposits. Hydrocarbon fluids, acting as reducing agents, migrate to shallow sand bodies through channels such as faults and unconformities, undergoing redox reactions with oxygen-containing and uranium-containing water, promoting uranium precipitation and enrichment. This method achieves efficient uranium ore location by identifying oil and gas escape channels and associated mineral-controlling factors.

[0078] In this embodiment, the positioning analysis is performed on the uranium-bearing geological bodies in the Yuejin No. 2 area, the Qigequan area, and the Yingxiongling area in the western Qaidam area.

[0079] During implementation, priority is given to identifying NW-SE trending deep faults (such as the Qigequan Fault and the Aral Fault) and secondary faults (reverse faults with a dip angle > 45°). These faults cut through source rocks and uranium reservoirs and are the main channels for vertical migration of oil and gas.

[0080] It is understandable that implementers can identify stratigraphic fractures, obtain oil and gas reservoir distribution characteristics, and assess uranium supply capacity based on historical documents in the area. The excerpt is placed at the end and will not be repeated here.

[0081] The preliminary drilling parameters include a preliminary drilling depth and a preliminary drilling quantity, wherein the preliminary drilling quantity corresponds to a number of drilling points in the preliminary drilling area;

[0082] During implementation, the preliminary drilling depth is determined according to the depth of the fracture.

[0083] The process for determining whether preliminary uranium standards are met includes:

[0084] The sample is judged for γ anomaly to preliminarily determine whether it meets the possibility of uranium formation. When the γ detection value is greater than the γ anomaly value, it is preliminarily judged to meet the possibility of uranium formation; when the γ detection value is less than or equal to the γ anomaly value, it is preliminarily judged not to meet the possibility of uranium formation.

[0085] When the possibility of uranium formation is initially met, hydrocarbon biomarkers are obtained to determine whether the uranium formation criteria are met;

[0086] In practice, the presence of trace elements in the samples was used to determine whether they were affected by uranium-containing, oxygen-rich water after diagenesis. In this example, the average V / Cr ratio for the mineralized sandstone samples was 1.316, while the average V / Cr ratio for the mineral-free sandstone samples was 1.062, reflecting an oxygen-rich environment. The average Ni / Co ratio for the mineralized sandstone samples was 2.455, while the average Ni / Co ratio for the mineral-free sandstone samples was 2.168, also reflecting an oxygen-rich environment. This suggests that the samples may have been affected by uranium-containing, oxygen-rich water after diagenesis.

[0087] Specifically, the process of obtaining hydrocarbon biomarkers includes selecting drilling samples, extracting saturated hydrocarbons from the samples, and performing GC-MS analysis.

[0088] In the implementation, Soxhlet extraction was used to extract saturated hydrocarbons from the sample sandstone, using HP6890GC / 5973MSD and GC-MS analysis was performed using an HP-5MS elastic quartz capillary column.

[0089] Specifically, the drilled sample is first crushed into a 200-mesh powder and then loaded into a filter paper cartridge. The filter paper cartridge and chloroform reagent are placed in a Soxhlet extractor and extracted for 72 hours to obtain chloroform pitch "A." Subsequently, after separating the asphaltenes through n-hexane centrifugation, chloroform pitch "A" is injected into a chromatography column. The saturated hydrocarbon fraction is separated using n-hexane, the aromatic hydrocarbon fraction is separated using dichloromethane + n-hexane (2:1 ratio), and the non-hydrocarbon fraction is separated using anhydrous ethanol + chloroform (93:7 ratio). Finally, the saturated hydrocarbon fraction is analyzed by gas chromatography-mass spectrometry.

[0090] The Odd-Even Preponderance (OEP) index reflects the degree of thermal evolution of organic matter. If the OEP values ​​of samples in the initial drilling area are within the standard range, it is judged that the organic matter in the area is highly mature and is not of modern sedimentary origin.

[0091] If the OEP value of the sample in the preliminary drilling area exceeds the standard range, it is judged that the organic matter in the area is of low maturity and is low-mature organic matter, which is organic matter deposited in modern times and does not meet the uranium generation standard;

[0092] After confirming that the organic matter is not from recent sedimentation, the maturity of the crude oil is reflected by the ratio of Ts to Tm. When Ts / Tm is greater than the standard ratio and matches the maturity reflected by the vitrinite reflectance, the crude oil in the area is judged to be in the mature stage.

[0093] The ratio of pristane to phytane (Pr / Ph) reflects the sedimentary environment. When the average value of the Pr / Ph values ​​of several samples is lower than the standard value, it is judged that the sedimentary environment of the sample is a highly reducing environment.

[0094] The gammacerane index (Ga / C30H) reflects the relative content of gammacerane in geological samples. When the gammacerane index is greater than the standard index, it is judged that the source rock of the sample was in a strong reducing environment during deposition.

[0095] Among them, the γ abnormal value is 300cps, the standard range is 1.0-1.2, the standard value is 0.7, the standard index is 0.15, and the standard ratio is 1.

[0096] After testing the samples obtained according to the initial drilling parameters, when the sedimentary environment of the samples is a reducing environment, the organic matter in the area is highly mature and is not organic matter deposited in modern times, and the crude oil is in a mature stage, and the samples are affected by uranium-containing oxygen-rich water after diagenesis, it is judged that the drilling points in the current preliminary drilling area corresponding to the samples have the possibility of uranium formation and preliminarily meet the uranium formation standards.

[0097] When the uranium formation standard is preliminarily met, a preliminary uranium formation possibility evaluation value is generated based on the ratio of the average value of V / Cr, the average value of Ni / Co, the average value of Pr / Ph to the standard value, and the ratio of the gammacerane index to the standard index.

[0098] Specifically, because the γ value is affected by multiple factors, it can only be used as a reference parameter to preliminarily determine the likelihood of a region containing uranium. High Pr / Ph ratios are typically found in oxidizing sedimentary environments, while lower Pr / Ph ratios are typically found under anoxic / hypersaline conditions. Reducing sedimentary environments prevent organic matter from being oxidized, preserving it. The higher the reducing nature, the greater the organic matter abundance and the greater the hydrocarbon-generating capacity. Due to the length of time required for uranium deposition to become uranium deposits, this method uses multiple parameters to preliminarily determine whether the sedimentary environment, organic matter maturity, crude oil maturity stage, and exposure to uranium-containing, oxygen-rich water at several drilling sites within the region meet the criteria for uranium mineralization.

[0099] The mineralization achievement condition is to trigger oil and gas escape. When the mineralization achievement condition is not met, the initial drilling area is determined to be transferred according to the fluid activity path.

[0100] Detect the vitrinite reflectance of the sample. When the vitrinite reflectance is lower than the critical range, it is judged that the source rock in the area at the current depth is in a low maturity stage, and the temperature range of the oil generation threshold is 60° to 80°;

[0101] When the vitrinite reflectance is in the critical range, it is judged that the source rock in the area at the current depth is in the mature stage, and the temperature range of the oil generation threshold is 80° to 150°;

[0102] When the vitrinite reflectance exceeds the critical range, it is judged that the source rock in the area at the current depth is in a high maturity stage, and the temperature range of the oil generation threshold is 150° to 200°;

[0103] Obtain the geothermal gradient of the area, multiply it by the initial drilling depth to calculate the actual formation temperature at the current drilling depth, and determine whether the oil generation threshold has been reached;

[0104] When the actual formation temperature is lower than the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature has not triggered oil and gas escape;

[0105] When the actual formation temperature is at the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature triggers oil and gas escape;

[0106] In this embodiment, the vitrinite reflectance of the source rock in the western Qaidam area is 0.7% to 1.0%, corresponding to an oil generation threshold temperature of 80° to 120°, which is at the peak stage of oil generation. The geothermal gradient in the western Qaidam area is about 3°C / 100m.

[0107] Wherein, the critical range is 0.7% to 1.2%.

[0108] Specifically, vitrinite reflectance is a crucial tool for determining the threshold temperature for oil generation. By analyzing the reflectance variations of organic matter in rocks, the temperature range for oil generation can be accurately determined, thereby guiding oil and gas exploration. The oil generation threshold is one of the fundamental conditions for oil and gas generation. Only when source rocks reach the threshold temperature for oil generation can they begin to generate significant amounts of oil, which is then converted into natural gas. The threshold temperature and depth of oil generation reflect the thermal evolution of a basin and are crucial indicators for analyzing the history of oil and gas generation in sedimentary basins. Determining the threshold depth and temperature for oil generation can predict the distribution and potential of oil and gas resources, providing a scientific basis for oil and gas exploration.

[0109] In step S2, the process of matching the maturity reflected by the vitrinite reflectance includes:

[0110] Compare the maturity reflected by vitrinite reflectance with the maturity reflected by Ts / Tm of the crude oil. If the maturity matches, determine the maturity stage. If the maturity does not match, determine the maturity stage based on the inclusion salinity.

[0111] Specifically, when the inclusion salinity is greater than the middle value of the standard salinity range, the maturity stage is determined based on the vitrinite reflectance;

[0112] When the inclusion salinity is less than or equal to the middle value of the standard salinity range, the maturity stage is determined based on the Ts / Tm ratio;

[0113] Specifically, vitrinite reflectance is applicable to Type III (terrigenous) and Type II (mixed source) organic matter, while other parameters must be combined for Type I (algae) source rocks. The Ts / Tm ratio, as an evaluation parameter, is not only related to maturity but also affected by the organic phase. Higher salinity is not conducive to the conversion of Tm to Ts, resulting in a lower Ts / Tm value. This method uses inclusion salinity to reflect paleo-salinity, corresponding to the selection of vitrinite reflectance or the maturity stage determined by the Ts / Tm ratio, thereby improving the accuracy of confirming the maturity of hydrocarbon fluids and avoiding adverse effects on subsequent analysis processes.

[0114] Select samples that have undergone alteration and discoloration near fractures, perform μXRF analysis on several of these samples, obtain the Sr and Rb contents in each sample, and compare the Sr / Rb ratio of the samples at the drilling points along the formation fracture.

[0115] If the Sr / Rb ratio of the sample at the drilling point in the rising direction of the formation fault is greater than the Sr / Rb ratio of the sample at the drilling point in the falling direction of the formation fault, it is determined that alkaline fluid activity exists in the rising direction of the formation fault, and the initial drilling area is moved along the rising direction of the formation fault;

[0116] If the Sr / Rb ratio of the sample at the drilling point in the ascending direction of the formation fault is smaller than that of the sample at the drilling point in the descending direction of the formation fault, it is determined that alkaline fluid activity exists in the descending direction of the formation fault, and the preliminary drilling area is moved along the descending direction of the formation fault;

[0117] After the initial drilling area is moved, the initial drilling depth in the initial drilling parameters is adjusted accordingly according to the height change of the formation fracture, and the initial drilling quantity is adjusted according to the preliminary uranium formation possibility evaluation value.

[0118] The number of drillings is positively correlated with the preliminary uranium potential assessment value.

[0119] Specifically, when several fractures meet the criteria for determining the regional movement direction, the fracture direction in which the homogenization temperature of the fluid inclusions in the sample is close to the determined oil generation threshold temperature is selected as the direction corresponding to the fluid in the main mineralization period;

[0120] The condition for determining the direction of regional movement is that the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture is greater than the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture.

[0121] In this example, the Sr content in the altered area of ​​the sample increased significantly, the Rb content increased slightly, and the contents of other elements did not change significantly.

[0122] Specifically, when the source rock in the current preliminary drilling area is in a low-maturity stage, this method determines that there are no oil and gas escape channels, and the preliminary drilling area needs to be moved. The fluid activity path is indicated based on the Sr content and the Rb content, and the preliminary drilling area is moved according to the fluid activity path. This improves the adaptability and flexibility of locating uranium deposits based on oil and gas escape channels. When there are several cracks in the formation fracture that meet the conditions for determining the regional movement direction, the main mineralization period fluid is limited in combination with the homogenization temperature of the inclusions, thereby improving the accuracy of controlling the movement of the preliminary drilling area and avoiding deviations in the movement direction.

[0123] In this embodiment, the fluid inclusions in the sample detected mainly include hydrocarbon inclusions, liquid inclusions, liquid hydrocarbon inclusions and brine inclusions.

[0124] Based on fluid inclusions, the laser micro-Raman spectrum of a single fluid inclusion is obtained to perform non-destructive determination of the inclusion composition.

[0125] During the implementation, laser Raman spectroscopy analysis of secondary inclusions was performed using a LabRAM HR Evolution laser confocal Raman microscope at a temperature of 25°C, a humidity of 30%, a laser wavelength of 532nm, and a scanning range of 100-4000cm-1.

[0126] The results show that the liquid phase in the inclusions is mainly composed of H2O, some inclusions contain asphalt, and the gas component is mainly CH4, reflecting the presence of hydrocarbon fluids in the corresponding drilling area after diagenesis.

[0127] Calculate the homogenization temperature of the fluid inclusions in the sample. The salinity of the fluid in the fluid inclusions can be converted based on the freezing point temperature. The formula is ωNaCl=0.00+1.78Tm-4.42×10 -2 Tm 2 +5.57×10 -4 Tm 3 , where ωNaCl is the mass fraction of NaCl, and Tm is the absolute value of the freezing point depression temperature

[0128] In this embodiment, the homogenization temperature of the fluid inclusions varies between 82.5-137.2°C, with an average of 121.4°C, and is mainly concentrated between 116.5-133.5°C; the salinity range of the inclusions is relatively large, between 0.88-14.55% (NaCleq), with an average of 5.82%, and is concentrated between 0.88-6.18%.

[0129] If the homogenization temperature exceeds the standard temperature range and the inclusion salinity exceeds the standard salinity range, the fluid inclusions in the sample are judged to be hydrothermal fluids and the uranium mineralization potential is lower than expected;

[0130] If the homogenization temperature is lower than the standard temperature range and the inclusion salinity is lower than the standard salinity range, the fluid inclusions in the sample are judged to be shallow atmospheric water, and the uranium mineralization potential needs to be further analyzed based on the geological environment;

[0131] If the homogenization temperature is within the standard temperature range and the inclusion salinity is within the standard salinity range, the fluid inclusions in the sample are judged to be oil and gas associated fluids, and the uranium mineralization potential is in line with expectations, verifying the coexistence of uranium minerals and hydrocarbon inclusions;

[0132] Wherein, the standard temperature range is 80-150° C., and the standard salinity range is 5-10%.

[0133] Specifically, fluid inclusions are diagenetic and mineralizing fluids captured and preserved in crystal defects or cavities during the growth of diagenetic minerals, recording rich original information such as pressure, temperature, and composition at the time of fluid capture. This method determines the uranium mineralization potential of the paleoenvironment in which the sample was formed by the homogenization temperature and salinity of the fluid inclusions in the sample. Hydrothermal fluids reflect the oxidizing possibility of the paleoenvironment, and the mineralization potential of uranium in this environment is low. Oil and gas associated fluids reflect the reducing nature of the paleoenvironment due to oil and gas escape, and the mineralization potential of uranium in this environment is high. Shallow atmospheric water cannot directly reflect the oxidizing nature of the paleoenvironment and requires further analysis. The uranium mineralization potential is evaluated by fluid property classification. Dual-parameter cross-validation avoids misjudgment of a single temperature indicator, limits the dynamic mineralization window, effectively defines the fluid window where oil and gas escape participates in uranium mineralization on the western margin of the Qaidam Basin, quantifies the matching between fluid properties and uranium precipitation conditions, significantly improves the prediction accuracy of sandstone-type uranium deposit targets, and is suitable for uranium resource evaluation in continental oil and gas basins.

[0134] Steps to further analyze uranium mineralization potential include:

[0135] The drilling samples were tested for carbon and oxygen isotopes of carbonates. 18 O SMOW -δ 13 C PDB Generate a diagram of CO isotope composition in western Qaidam area;

[0136] The results of whole-rock carbon and oxygen isotope analysis show that the carbon isotope δ 13 C V-PDB The value range is -5.34‰~-0.68‰, with an average value of -2.81‰. The oxygen isotope δ 18 O V-PDB The carbon isotope δ 13 C V-PDB The value range is -3.53‰~-0.59‰, with an average value of -1.53‰. The oxygen isotope δ 18 O V-PDB The carbon isotope δ 13 C V-PDB The value range is -3.2‰~1‰, with an average value of -1.79‰. The oxygen isotope δ 18 O V-PDB It ranges from -11.69‰ to -7.21‰, with an average of -9.79‰.

[0137] Carbonates are divided into three types according to their carbon and oxygen isotope composition characteristics, as shown in the figure.

[0138] Zone I is diagenetic carbonatite, indicating that carbonation was formed during the sedimentary diagenesis process of the stratum. 13 C>-10‰, δ 18 O<0‰; Zone II is carbonate related to biogas, emphasizing the participation of biological action in its formation process. 18 O has a wide range, δ 13 C>0‰; Zone III is carbonate related to organic matter, that is, the source of carbon in the carbonation process is mainly organic oil and gas fluids in the basin.

[0139] According to the proportion of samples in different compositional characteristic types, when the proportion of samples in zone II is less than the critical proportion, it is judged that the genesis of the samples is not related to biological action, some samples are of inorganic origin, and the source of carbon in some samples is mainly organic oil and gas fluids in the basin;

[0140] When the proportion of samples in zone II is less than the critical proportion, it is judged that the origin of the sample is related to biological action, and the carbon source of the sample is affected by biological action, such as carbonaceous plant debris, and the criteria for adjusting the homogenization temperature and inclusion salinity are;

[0141] Specifically, the upper limit of the standard temperature range is reduced, and the upper limit of the standard salinity range is increased.

[0142] Specifically, organic acids (such as acetic acid) produced by the degradation of plant debris can complex Na + , K + Plasma reduces the apparent salinity of the fluid, and the measured value of ωNaCl may be underestimated by 5-10%; carbonaceous plant debris undergoes pyrolysis during burial, releasing organic acids and hydrocarbons, which leads to local temperature increases and causes the homogenization temperature to be artificially high; adjusting the judgment criteria of fluid properties can improve the accuracy of assessing uranium mineralization potential.

[0143] Among them, the critical proportion is 15%.

[0144] In this example, most samples are of inorganic origin, and the carbon source of some samples is mainly organic oil and gas fluids in the basin.

[0145] Specifically, when carbonates fall into an inorganic origin zone, it indicates that the diagenetic fluid is mainly atmospheric precipitation or deep hydrothermal fluids. Since inorganic fluids are usually poor in organic matter and lack reducing ability, they are not conducive to uranium reduction, and therefore need to rely on later hydrocarbon reduction to precipitate. This method uses carbon and oxygen isotope analysis of several samples to determine whether the area where the samples are located has the conditions where uranium is first transported by inorganic fluids and then reduced and fixed by hydrocarbons, thereby reflecting the possibility of uranium mineralization, that is, the oxidizing fluid and the reducing fluid react at the contact interface to generate insoluble uranium minerals, which work together with the upper oxidizing fluid to form an oxidation-reduction geochemical barrier, leading to the possibility of large-scale uranium enrichment and mineralization. It is determined that in inorganic-dominated areas (such as northwestern Qaidam), the exploration strategy should focus on finding evidence of organic fluid infiltration (such as hydrocarbon inclusions and carbonaceous debris) near the fault zone, which optimizes the strategic method of uranium exploration and positioning and improves the accuracy of positioning.

[0146] The process of identifying the target area includes:

[0147] When predicting and delineating exploration target areas, areas that meet the following conditions simultaneously are preferred:

[0148] The structural location is at the intersection of faults (e.g. the Seven Springs Fault intersects with the NE-trending fault);

[0149] The stratigraphic assemblage contains unconformities and gray-green altered sand bodies (chlorite > 5%);

[0150] The geochemical characteristics include γ value > 100cps and Sr / Rb > 1.5.

[0151] Specifically, the study shows that in the western Qaidam area, uranium mineralization is mainly distributed on the periphery of oil and gas fields on a horizontal plane; in the mineralized strata, sandstone-type uranium deposits are usually located above or in the same strata as oil and gas strata, and this superposition relationship helps the transformation of oil and gas on sandstone-type uranium deposits, thereby leading to uranium enrichment and mineralization; when selecting target areas for drilling exploration, this method delineates the target areas from three directions: structural location, stratigraphic combination, and geochemical signs, reducing the workload of ineffective exploration and improving the efficiency of uranium mine positioning.

[0152] When the uranium mineralization potential is in line with expectations, or the proportion of samples in Zone II is less than the critical proportion, drilling is conducted to verify the coexistence of uranium minerals (uraninite, pitchblende) and hydrocarbon inclusions (CH4 fluorescence);

[0153] In this embodiment, the Qigequan area in western Chai is taken as an example:

[0154] Identify the Qigequan Fault and the secondary SW-trending fault; detect high γ anomaly (300 cps) and C in the gray-green sandstone near the fault. 27Steranes are dominant; drilling verification confirmed the coexistence of uranium minerals and hydrocarbon inclusions in the area when uranium rock and asphalt coexist, and the ore body is located in the slope zone of the upper wall of the fault.

[0155] Specifically, uranium mineralization in the Yuejin-2 area is primarily distributed within gray-green sand bodies. Carbon and oxygen isotope analysis reveals that the formation of cement in the uranium-enriched areas is influenced by organic carbon. This suggests that sandstone-type uranium enrichment in this area is the result of the interaction between two fluid systems: hydrocarbon-rich basinal fluids and uranium-bearing shallow-source fluids fed from the basin margin. The location of uranium enrichment is primarily controlled by the redox interface between the upward-flowing reducing fluid and the downward-flowing oxidizing fluid.

[0156] In this example, the infiltration and migration of uranium-containing oxygen-containing water occurs, and the uranium-containing fluid enters the rock through the cracks in the plagioclase and the pores in the clay minerals. Some of the uranium in the solution reacts chemically with the minerals in the rock and is retained.

[0157] In areas with intense tectonic activity, rock fissures are highly developed and permeability is significantly enhanced, providing more favorable conditions for the infiltration and migration of uranium-containing and oxygen-containing water, enabling it to diffuse deeper into the strata.

[0158] Tectonic evolution causes uranium-containing oxygen-containing water to meet reducing substances (such as oil, gas, carbonized plant debris, etc.) at specific structural locations, thereby initiating redox reactions. The redox reactions between uranium-containing oxygen-containing water and reducing fluids change the occurrence state of uranium, promoting the precipitation and enrichment of uranium.

[0159] Tectonic movement-induced stratum deformation and fluid migration reactivate and migrate uranium pre-enriched during the sedimentary diagenesis phase. As uranium-containing and oxygen-containing water continues to infiltrate, interacting with minerals and fluids in the stratum, uranium is further enriched in favorable tectonic locations, ultimately forming uranium deposits.

[0160] Specifically, through experimental analysis of carbon and oxygen isotopes, fluid inclusions, elemental geochemical characteristics, and organic geochemical characteristics, it is believed that there are two main causal relationships between oil and gas and uranium mineralization in the western Qaidam area: (1) A large amount of reducing media (carbonized plant debris) is developed in the target layer, which increases the reduction capacity of the target layer sand body and is conducive to uranium enrichment and mineralization; (2) Some target layers themselves have less reducing media, but there are major oil and gas reservoirs in the region, and the oil and gas content in the sand body is high, which not only improves the reduction properties of the sand body, but also increases the adsorption and porosity after alteration, which is conducive to uranium enrichment.

[0161] In this example, under the influence of the Himalayan movement, the tectonic stress field in the western Qaidam region underwent a significant shift from early tension to mid- to late compression. Early tensional stress led to the development of normal faults and rift structures, forming geological units such as rift lake basins. These structures provided initial storage and migration space for groundwater, including uranium-containing and oxygen-containing water, and served as the initial conditions for the evolution of the entire uranium-containing and oxygen-containing water system. With the dominance of compressional stress in the mid- to late-stage Himalayan movement, the strata underwent intense folding and thrust faulting, resulting in the formation of anticlines, synclines, and numerous associated fault structures. These changes significantly altered the original structure of the strata and the physical and mechanical properties of the rocks, shaping a complex and diverse geological environment and creating new conditions for the subsequent infiltration and migration of uranium-containing and oxygen-containing water.

[0162] From the perspective of uranium mineralization, tectonic evolution is more closely related to the infiltration of uranium-bearing and oxygen-bearing water. Tectonic evolution promotes the interaction of uranium-bearing and oxygen-bearing water with reducing substances (such as oil, gas, and carbonized plant debris) at specific tectonic locations, triggering redox reactions. In the tectonic skylights of the Yingdong anticline, oxygen-rich uranium-bearing and oxygen-bearing water interacts with oil and gas fluids escaping from deep. Near interfaces such as tectonic fractures and unconformities, these redox reactions alter the occurrence of uranium, promoting uranium precipitation and enrichment. Simultaneously, tectonic-induced stratum deformation and fluid migration remobilize and mobilize uranium pre-enriched during the sedimentary diagenetic stage. As the uranium-bearing and oxygen-bearing water continues to infiltrate, through interaction with minerals and fluids in the stratum, uranium is further enriched in favorable tectonic locations, ultimately forming uranium deposits. This uranium enrichment process is closely related to the temporal and spatial alignment of tectonic evolution. For example, during the late Neogene tectonic movement in the western Qaidam Basin, tectonic deformation provided the essential dynamics and spatial conditions for the activation, migration, and enrichment of uranium.

[0163] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0164] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A uranium mine positioning method for controlling oil and gas escape channels, characterized in that: include: Identify formation faults, analyze the distribution characteristics of oil and gas reservoirs, evaluate uranium supply capacity, and obtain superimposed maps of faults and oil-bearing areas; Determine a preliminary drilling area based on the superimposed map, drill according to preliminary drilling parameters to obtain a number of samples, determine whether the drilling point preliminarily meets the uranium formation standard based on gamma anomaly determination and sedimentary environment characteristics of the samples, and generate a preliminary uranium formation possibility evaluation value; For drilling points that initially meet the uranium formation criteria, determine the temperature range of the oil generation threshold based on the vitrinite reflectance of the sample, determine whether the mineralization conditions are met based on the geothermal gradient and the initial drilling depth corresponding to the drilling point, and determine whether to relocate the initial drilling area based on the fluid activity path; Determine the enrichment of Sr and Rb near the fractures based on the Sr and Rb contents in each sample, indicate the fluid flow path, and determine the direction of moving the preliminary drilling area and adjust the initial drilling parameters based on the fluid flow path and the preliminary uranium formation possibility evaluation value; When there are several cracks in the formation fracture that meet the conditions for determining the regional movement direction, the main mineralization period fluid is defined in combination with the homogenization temperature of the inclusions, and the direction corresponding to the main mineralization period fluid is taken as the fluid movement path; Classify the fluid properties based on the homogenization temperature and salinity of the fluid inclusions in the sample to determine whether the uranium mineralization potential of the paleoenvironment in which the sample was formed meets expectations or requires secondary analysis of uranium mineralization potential; Isotope testing is performed on samples to determine the compositional characteristics of the samples. Based on the proportion of samples in different compositional characteristics, it is determined whether the genesis of the samples is related to biological processes, and the criteria for determining uranium mineralization potential are adjusted accordingly. When the uranium mineralization potential is in line with expectations, or the sample genesis is not related to biological activity, drilling is used to verify the coexistence of uranium minerals and hydrocarbon inclusions.

2. The uranium mine positioning method for controlling oil and gas escape channels according to claim 1 is characterized in that: The process of determining the temperature range of the oil generation threshold includes: Detect the vitrinite reflectance of the sample. When the vitrinite reflectance is lower than the critical range, it is judged that the source rock in the area at the current depth is in a low maturity stage; When the vitrinite reflectance is in the critical range, it is judged that the source rock in the area at the current depth is in the mature stage; When the vitrinite reflectance exceeds the critical range, it is judged that the source rock in the area at the current depth is in a high maturity stage; The temperature range of the oil generation threshold is determined according to the maturity stage of the source rock.

3. The uranium mine positioning method for controlling oil and gas escape channels according to claim 2 is characterized in that: The mineralization condition is to trigger the escape of oil and gas; determining the actual formation temperature based on the geothermal gradient of the preliminary drilling area and the initial drilling depth; When the actual formation temperature is lower than the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature has not triggered oil and gas escape, and the initial drilling area is shifted according to the fluid activity path; When the actual formation temperature is at the corresponding oil generation threshold temperature, it is determined that the current actual formation temperature triggers oil and gas escape.

4. The uranium mine positioning method for controlling oil and gas escape channels according to claim 3 is characterized in that: The process of shifting the initial drilling area based on the path of fluid activity includes; Select samples that have undergone alteration and discoloration near the cracks, and perform μXRF analysis on several samples that have undergone alteration and discoloration to obtain the Sr and Rb contents in each sample; Determine whether to move the preliminary drilling area along the rising direction or the falling direction of the formation fault according to whether the Sr / Rb ratio of the sample at the drilling point in the rising direction of the formation fault is greater than the Sr / Rb ratio of the sample at the drilling point in the falling direction of the formation fault; After the preliminary drilling area is moved, the initial drilling depth in the initial drilling parameters is adjusted according to the height change of the formation fracture, and the initial drilling quantity is adjusted according to the preliminary uranium formation possibility evaluation value.

5. The uranium mine positioning method for controlling oil and gas escape channels according to claim 4 is characterized in that: The processes that define the fluids during the main mineralization period include; When several fractures meet the criteria for determining the regional movement direction, the fracture direction in which the homogenization temperature of the fluid inclusions in the sample is closest to the determined oil generation threshold temperature is selected as the direction corresponding to the fluid in the main mineralization period; The condition for determining the direction of regional movement is that the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture is greater than the Sr / Rb of the sample at the drilling point in the direction of the rising crack in the formation fracture.

6. The uranium mine positioning method for controlling oil and gas escape channels according to claim 5 is characterized in that: The process of determining uranium mineralization potential includes; If the homogenization temperature exceeds the standard temperature range and the inclusion salinity exceeds the standard salinity range, the fluid inclusions in the sample are judged to be hydrothermal fluids and the uranium mineralization potential is lower than expected; If the homogenization temperature is lower than the standard temperature range and the inclusion salinity is lower than the standard salinity range, the fluid inclusions in the sample are judged to be shallow atmospheric water, and the uranium mineralization potential needs to be further analyzed based on the geological environment; If the homogenization temperature is within the standard temperature range and the inclusion salinity is within the standard salinity range, the fluid inclusions in the sample are judged to be oil and gas associated fluids, and the uranium mineralization potential is in line with expectations.

7. The uranium mine positioning method for controlling oil and gas escape channels according to claim 6, characterized in that: The process of further analyzing the uranium mineralization potential includes; The drilling samples were tested for carbon and oxygen isotopes of carbonates, and carbonates were divided into three types according to their carbon and oxygen isotope composition characteristics; When the proportion of samples in zone II is less than the critical proportion, it is judged that the cause of the sample is not related to biological action; When the proportion of samples in zone II is less than the critical proportion, it is judged that the origin of the samples is related to biological action, the carbon source of the samples is affected by biological action, and the judgment criteria of homogenization temperature and inclusion salinity are adjusted.

8. The uranium mine positioning method for controlling oil and gas escape channels according to claim 7 is characterized in that: When uranium rocks coexist with asphalt, it is confirmed that uranium minerals and hydrocarbon inclusions coexist in the area.

9. The uranium mine positioning method for controlling oil and gas escape channels according to claim 8, characterized in that: The process of determining whether a drill site meets the initial uranium production criteria includes: Conduct gamma anomaly assessment on the sample to preliminarily determine whether it meets the uranium formation criteria. If it preliminarily meets the uranium formation criteria, obtain hydrocarbon biomarkers to determine whether it meets the uranium formation criteria. The odd-even dominance index reflects the degree of thermal evolution of organic matter and determines the maturity of organic matter in the region and whether it is organic matter deposited in the modern era. The average value of the Pr / Ph value and the gammacerane index of the sample are used to determine whether the deposition environment of the sample is a reducing environment; The maturity of the crude oil in the region can be determined by comparing the Ts / Tm ratio with the maturity reflected by the vitrinite reflectance. When the sedimentary environment of the sample is a reducing environment, the organic matter in the area is not organic matter deposited in modern times, and the crude oil is in a mature stage, and the sample is affected by uranium-containing oxygen-rich water after diagenesis, it is judged that the drilling point in the current preliminary drilling area corresponding to the sample has the possibility of uranium formation and preliminarily meets the uranium formation standard.

10. The uranium mine positioning method for controlling oil and gas escape channels according to claim 9, characterized in that: The process of determining whether the maturity matches is as follows: When the maturity reflected by the vitrinite reflectance and the Ts / Tm ratio are inconsistent, the maturity stage is determined based on whether the inclusion salinity is greater than the middle value of the standard salinity range.

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