Method for identifying hot calcite and hydrothermal calcite

Abstract

The invention relates to a method for identifying hot calcite and hydrothermal calcite. The method comprises the following steps: preparing sample slices from calcite samples at the same layer and in different occurrence states; determining the organic matter type and abundance characteristics of each sample slice by using an organic petrology analysis method; determining rare earth element data of each sample slice by utilizing an element geochemical analysis method; determining a forming mode of the sample slice according to the organic matter type, the abundance characteristic and the rare earth element data of the sample slice; wherein the forming mode comprises a hot water deposition mode and a hydrothermal deposition mode.

Description

Technical Field

[0001] The present invention relates to the field of petroleum exploration technology, and in particular to a method for identifying hydrothermal calcite and hydrothermal calcite. Background Art

[0002] At present, many scholars have confirmed that the spar calcite veins in rocks are related to hydrothermal activity, but there is no systematic method to distinguish the calcite formed under the two hydrothermal deposition modes. Therefore, it is particularly important to provide a scientific method to identify the deposition mode of hydrothermal calcite. Summary of the invention

[0003] In view of the above problems, the present invention provides a method for identifying hydrothermal calcite and hydrothermal calcite. The method is based on petrology, elemental geochemistry and isotope geochemistry to comprehensively identify the formation mode of hydrothermal and hydrothermal deposited calcite. It can more accurately select samples to study the impact of hydrothermal activity on the type and provenance of organic matter in source rocks.

[0004] In a first aspect, the present application provides a method for identifying hydrothermal calcite and hydrothermal calcite, the method comprising: making sample slices from calcite samples of the same stratum and different occurrences; determining the organic matter type and abundance characteristics of each sample slice using organic petrology analysis; determining the rare earth element data of each sample slice using elemental geochemical analysis; determining the deposition mode of the sample slice based on the organic matter type, abundance characteristics and the rare earth element data of the sample slice; wherein the deposition mode comprises: hydrothermal deposition mode and hydrothermal deposition mode.

[0005] Compared with the related art, the present application provides a method for identifying hydrothermal calcite and hydrothermal calcite, the method comprising: preparing sample slices from calcite samples of the same layer and different occurrences; determining the organic matter type and abundance characteristics of each sample slice using organic petrology analysis; determining the rare earth element data of each sample slice using elemental geochemistry analysis; determining the deposition mode of the sample slice according to the organic matter type, abundance characteristics and the rare earth element data of the sample slice; wherein the deposition mode comprises: hydrothermal deposition mode and hydrothermal deposition mode. The present application provides a method for comprehensively identifying the formation mode of hydrothermal and hydrothermal deposited calcite based on petrology, elemental geochemistry and isotope geochemistry, which can more accurately select samples to study the influence of hydrothermal activity on the organic matter type and source of source rocks.

[0006] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or be understood by implementing the present application. Other advantages of the present application can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The accompanying drawings are used to provide an understanding of the technical solution of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present application and do not constitute a limitation on the technical solution of the present application.

[0008] Figure 1 A flow chart of a method for identifying hot water calcite and hydrothermal calcite according to an embodiment of the present application;

[0009] Figure 2 A schematic diagram of sample selection for the Lucaogou Formation in the Jimusar Sag in some exemplary embodiments;

[0010] Figure 3 Schematic diagram of the distribution of organic petrology and elemental geochemical characteristics of calcite of different occurrences in the Lucaogou Formation in the Jimusar Sag in some exemplary embodiments. DETAILED DESCRIPTION

[0011] The present application describes multiple embodiments, but the description is exemplary rather than restrictive, and it is obvious to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present application. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are also possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0012] The present application includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features and elements disclosed in the present application may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present application may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other restrictions. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0013] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps of the specific order described. As will be understood by those of ordinary skill in the art, other sequences of steps are also possible. Therefore, the specific sequence of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps of performing them in the order written, and those skilled in the art can easily understand that these sequences can be changed and still remain within the spirit and scope of the embodiments of the present application.

[0014] For shale oil to form a certain economically recoverable scale, the enrichment of its organic matter is a key factor. Even if its maturity is not high, in-situ heating technology can be used to convert shale into economically recoverable resources underground. At present, the research on the enrichment of organic matter in shale is not only focused on the sedimentary perspectives such as paleo-tectonic, paleoclimate and paleo-lake water bodies, but more and more people are paying more attention to the role of event sedimentation in organic matter enrichment. Because event sedimentation will break the balance of the original ecosystem of the lake, it will directly affect the corresponding sedimentary conditions such as salinity, acidity and alkalinity, and redox properties of the water body, and will also indirectly affect the primary productivity of the lake, such as algae, plankton and microorganisms. Studies have shown that hot water deposition occurred during the formation of many marine and terrestrial high-quality source rocks. The impact of lake bottom hot water activity on organic matter accumulation is mainly reflected in the changes in lake bottom redox conditions and nutrient input. The hot water at the bottom of the lake brings a large amount of reducing gases (CO2, SO2, H2S, etc.) and soluble ion compounds, which may lead to an increase in the salinity of the lake and cause obvious water stratification, thereby enhancing the accumulation of redox-sensitive elements (such as V, Ni, U and Mo), forming an oxygen-deficient or even anaerobic environment at the bottom of the water column, which is conducive to the preservation of organic matter. At the same time, hot water releases a large amount of nutrients (P, Fe, Mn, Cu, Na, etc.) into the lake basin. Phosphorus and iron are essential nutrients for the growth of plankton. Therefore, hot water activity also plays an important role in improving the productivity of ancient lakes. The above research results all reflect the impact of hot water deposition on the burial abundance of organic matter in sediments. However, in the course of the research, it was found that some hydrothermal activities would erupt from the sediments, mix with the sedimentary water, change the properties of the sedimentary water, and thus affect the enrichment of organic matter; another situation is that the hydrothermal fluid did not erupt from the sediments, but mixed and cooled with the formation water in the sediments. This deposition pattern would not affect the enrichment of organic matter in the shale; therefore, in sedimentary strata, how to identify the cores and lithofacies of hydrothermal deposition patterns and hot water deposition patterns is a key issue in tracking the impact of hydrothermal activity on organic matter enrichment.

[0015] In order to achieve the above-mentioned purpose, the present invention provides a method for comprehensively identifying the formation mode of hydrothermal deposited calcite and hot water deposited calcite based on petrology, elemental geochemistry and isotope geochemistry. The method integrates the organic petrology, rare earth element geochemistry and cathode luminescence of calcite of different occurrences and their surrounding rocks to identify the formation mode of hydrothermal minerals, which is conducive to accurately selecting suitable samples to study the influence of hydrothermal fluids on organic matter enrichment.

[0016] The embodiment of the present invention provides a method for identifying hydrothermal calcite and hydrothermal calcite, such as Figure 1 As shown, the method includes steps S100-S130:

[0017] S100: Sample thin sections are made from calcite samples of the same layer and different occurrences;

[0018] S110: Use organic petrology analysis to determine the type and abundance characteristics of organic matter in each sample thin section;

[0019] S120: Determine the rare earth element data of each sample slice using element geochemical analysis method;

[0020] S130: Determine the sedimentation mode of the sample slice according to the organic matter type and abundance characteristics of the sample slice and the rare earth element data.

[0021] In this embodiment, the deposition modes include: hot water deposition mode and hydrothermal deposition mode.

[0022] In an exemplary embodiment, sample slices are prepared from calcite samples of different occurrences with similar burial depths in the same layer, including:

[0023] The first step is to determine the period of each calcite sample using the cathode luminescence method for calcite samples of the same layer and different occurrences; in this step, the calcite samples of different occurrences include calcite samples that penetrate the layers and calcite samples that are parallel to the layers, such as Figure 2 As shown, Figure 2 Figure a in the middle shows bedding-parallel vein calcite. Figure 2 Figure b in the middle shows interlayered vein calcite.

[0024] The second step is to make sample slices from the calcite samples of the same period.

[0025] In an exemplary embodiment, the sample slices include: a calcite vein sample slice, a first calcite surrounding rock sample slice, and a second calcite surrounding rock sample slice. In this embodiment, the first calcite surrounding rock is the surrounding rock adjacent to the calcite; the second calcite surrounding rock is the surrounding rock far from the calcite.

[0026] In an exemplary embodiment, the thickness of the sample slice is 0.04 mm and does not include a cover glass. In the specific manufacturing process, non-luminescent 502 glue is selected to be glued to the slide to avoid interference caused by fluorescence of the bottom glue during fluorescence observation. The thickness of the rock slice is set to 0.04 mm and is not covered with a cover glass. The purpose is to facilitate fluorescence observation and to perform micro-area experimental analysis on the same slice.

[0027] In an exemplary embodiment, the organic petrology analysis method is used to determine the organic matter type and abundance characteristics of each sample thin section, including: performing fluorescent thin section observation on the sample thin sections to determine the organic matter type and abundance characteristics of each sample thin section. By performing fluorescent thin section observation, the location of the calcite vein body can be determined, and the organic matter type and abundance characteristics in the surrounding rocks adjacent to and far from the calcite vein body can be observed and photographed; wherein, the fluorescent observation can be observed using a Zeiss microscope. The organic matter type is mainly characterized by the morphology of the organic matter, and the degree of development is mainly compared by observing the surface ratio of the organic matter.

[0028] In an exemplary embodiment, the rare earth element data of each sample slice is determined by using an elemental geochemical analysis method, including: performing in-situ micro-area trace element analysis on different sample slices to determine the rare earth element data of each sample slice. In this embodiment, the rare earth elements include: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu elements, wherein La, Ce, Pr, Nd, Sm and Eu are light rare earth elements (LREE), and Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu are heavy rare earth elements (HREE).

[0029] In an exemplary embodiment, after determining the rare earth element data of each sample slice using elemental geochemical analysis, the method further includes:

[0030] The first step is to perform chondrite standardization on the rare earth element data to obtain standardized rare earth element data;

[0031] The second step is to use the standardized rare earth element data to establish the rare earth element distribution characteristic curve.

[0032] In an exemplary embodiment, determining the formation mode of the sample slice according to the organic matter type and abundance characteristics of the sample slice includes:

[0033] If the first sample thin section and the second sample thin section have the same organic matter type or the same abundance characteristics, it is determined that the calcite vein sample thin section is a hydrothermal deposition model;

[0034] If the organic matter type of the first sample thin section is different from that of the second sample thin section or the abundance characteristics are different, it is determined that the calcite vein sample thin section is a hydrothermal deposition model. The surrounding rock of the first calcite is the surrounding rock adjacent to the calcite; the surrounding rock of the second calcite is the surrounding rock far from the calcite.

[0035] In this embodiment, the method for identifying hot water calcite and hydrothermal calcite in this embodiment is mainly based on the following principles:

[0036] (1) Identification of hydrothermal calcite: The elements deposited by hydrothermal fluids have not been diluted by sedimentation, transportation and burial. The concentration of rare earth elements is higher than that of the surrounding rocks, and the distribution pattern is different from that of the surrounding rocks.

[0037] (2) If calcite is formed by hydrothermal deposition in lake water, it will affect the changes in the source type and abundance of organic matter during the deposition process.

[0038] According to (1) and (2), we can get the following conclusions:

[0039] In the hydrothermal deposition model, there will be obvious differences in the organic petrological characteristics of the surrounding rocks near and far from the calcite; if calcite is formed by the mixing of hydrothermal fluids and newly deposited formation water, there will be no difference in the organic petrological characteristics of the surrounding rocks near and far from the calcite veins.

[0040] In an exemplary embodiment, determining the formation mode of the sample slice according to the rare earth element data includes:

[0041] If the rare earth element concentration of the calcite vein sample thin section is greater than the rare earth element concentration of the first sample thin section and the rare earth element concentration of the second sample thin section, and the rare earth element distribution characteristic curve of the first sample thin section and the distribution characteristic curve of the second sample thin section have the same characteristics, then the calcite vein sample thin section is in hydrothermal deposition mode;

[0042] If the rare earth element concentration of the calcite vein is greater than the rare earth element concentration of the first sample thin slice, and the rare earth element distribution characteristic curve of the first sample thin slice is different from the rare earth element distribution characteristic curve of the second sample thin slice, then the calcite vein sample thin slice is a hot water deposition mode.

[0043] In this embodiment, the method for identifying hot water calcite and hydrothermal calcite in this embodiment is mainly based on the following principles:

[0044] (1) Identification of hydrothermal calcite: The elements deposited by hydrothermal fluids have not been diluted by sedimentation, transportation and burial. The concentration of rare earth elements is higher than that of the surrounding rocks, and the distribution pattern is different from that of the surrounding rocks.

[0045] (2) If calcite is formed by hydrothermal deposition in lake water, it will affect the changes in the source type and abundance of organic matter during the deposition process.

[0046] (3) Consistent with the above hypothesis, if it is a hydrothermal deposition model, then the abundance of rare earth elements far away from the calcite veins will be diluted by lake water and reduced, and the rare earth element distribution patterns of the surrounding rocks near the calcite and far away from the calcite will be different. The rare earth element characteristics of the surrounding rocks near the calcite will be between those of the calcite veins and those far away from the calcite veins. If it is a hydrothermal deposition model, the rare earth element distribution patterns and concentrations near the calcite and far away from the calcite veins should be consistent.

[0047] In an exemplary embodiment, the deposition mode of the sample slice is determined comprehensively based on the organic matter type and abundance characteristics of the sample slice and the rare earth element data.

[0048] The embodiments of the present application have the following technical effects:

[0049] (1) The chain of evidence is sufficient, with both visual petrological analysis and elemental geochemical data as support;

[0050] (2) The method is simple and conventional, the amount of sample used is small, and all experiments can be completed with only rock thin sections. In addition, the in-situ experiment does not destroy the integrity of the sample, and is highly operational and reliable.

[0051] Example 1

[0052] A method for identifying hydrothermal calcite and hydrothermal calcite, the specific implementation steps are as follows:

[0053] The first step is to collect calcite samples of different occurrences in the same layer;

[0054] The second step is to make sample slices from calcite samples of different occurrences;

[0055] The third step is to conduct petrological observation and cathodoluminescence observation on the cathodoluminescent thin sections to determine the formation period of the calcite veins. Generally, after the period is determined, the early-formed calcite is selected for subsequent analysis.

[0056] The fourth step is to conduct fluorescent thin section observation, mainly focusing on the type and abundance characteristics of organic matter in the calcite vein area, the surrounding rock adjacent to the calcite vein area, and the surrounding rock far away from the calcite vein area.

[0057] Step 5: Determine whether it is a hydrothermal deposition model or a hot water deposition model through comparative analysis of organic petrology.

[0058] In this step, the sources and development levels of organic matter in the surrounding rocks near the calcite and those far from the calcite are compared. If the sources of organic matter in the surrounding rocks near the calcite and those far from the calcite are different, or the organic matter is more developed, it means that the calcite is hydrothermal deposited calcite; if there is not much difference in the sources and development levels of organic matter in the surrounding rocks at different locations, it means that calcite deposition has no effect on the enrichment of organic matter in the shale, and it can be inferred that it is hydrothermal deposited calcite.

[0059] Step 6: Perform in-situ micro-area major and trace element analysis on the sample slices, and perform chondrite standardization on the in-situ rare earth element data;

[0060] In this step, in-situ micro-area major and trace element analysis of different sample thin sections is performed mainly to consider the differences in rare earth elements in the calcite vein location, and in the surrounding rocks adjacent to and far from the calcite vein.

[0061] In situ major and trace elements were analyzed using a quadrupole plasma mass spectrometer (i Cap-RQ ICP-MS) equipped with a 193 nm ARF excimer laser ablation.

[0062] In this step, the rare earth elements refer to La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu elements, among which La, Ce, Pr, Nd, Sm and Eu are light rare earth elements (LREE), and Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu are heavy rare earth elements (HREE).

[0063] After the in-situ rare earth element data are standardized by chondrites, a distribution characteristic curve of the rare earth elements after chondrite standardization is established. The distribution characteristic curve means that the horizontal axis is the element name and the vertical axis is the standardized rare earth element concentration.

[0064] Step 7: Elemental geochemical analysis to determine the sedimentation pattern;

[0065] First, the rare earth element concentrations of calcite veins in different samples are compared. The high concentration can be preliminarily judged as hydrothermal calcite, and the low concentration can be judged as hydrothermal sedimentary calcite;

[0066] Secondly, the rare earth element distribution characteristics of the calcite vein body, the surrounding rock adjacent to the calcite vein body and the surrounding rock far away from the calcite vein body in the sample thin section are compared. If there is no difference in the rare earth element distribution characteristics of the calcite vein body and the surrounding rock far away from the calcite vein body, it indicates that the calcite vein body is hydrothermal deposited calcite; Figure 3 If the rare earth element distribution characteristics of the calcite vein body are between those of the calcite vein body and the surrounding rock far away from the calcite, it means that the calcite is hydrothermal deposited calcite, such as Figure 3As shown in Figures g and h.

[0067] Step 8. Determine the sedimentation pattern by combining organic petrology and elemental geochemical analysis.

[0068] Example 2

[0069] The Lucaogou Formation in the Jimusar Sag is the first demonstration base for shale oil exploration and development in my country. Its organic matter abundance is generally high, with an average value of about 6%, and both type I and II1 kerogens are developed, which has strong oil generation potential. Previous studies have shown that the area belongs to saline lake basin sedimentation, and the presence of high organic matter abundance is related to hydrothermal activity. Its core characteristics are mainly manifested in the appearance of special calcite veins in the study area. However, calcite veins of different occurrences may represent different forms of formation modes, mainly including two categories. One is calcite formed by hydrothermal fluid entering the sedimentary water body, which can be subdivided into hot water deposition. This process often affects the abundance and source of organic matter in sedimentary shale; the other is that hydrothermal fluid is only filled in the newly deposited shale, which can be subdivided into hydrothermal deposition and will not affect the quality of shale during the deposition period. Therefore, in order to trace the sedimentary phenomena of the two hydrothermal activities, there must be a reliable identification basis. In the past, it was only judged by core and thin section observation, lacking objective data support.

[0070] The specific implementation process of the method for distinguishing hydrothermal calcite and hot water calcite in the Lucaogou Formation of Jimusar Sag is as follows:

[0071] (1) Collect calcite samples of different occurrences with similar burial depths in the same layer;

[0072] Samples were selected from the coring well X1 of the Lucaogou Formation in the Jimusar Sag, and samples of bedding-parallel vein calcite and bedding-through vein calcite were selected, such as Figure 3 As shown, Figure 3 Figure a in the middle shows the interlayer vein calcite at 3711.73 m in Well X1. Figure 3 Figure b shows interbedded vein calcite at 3722.38 m in Well X1. The selected sample rich in interbedded vein calcite is buried at a deeper depth.

[0073] (2) making thin sections of the selected samples;

[0074] The thickness of the thin section is 0.04 mm and is not covered with a cover glass to prevent the laser from penetrating the rock during the in situ experiment.

[0075] (3) Conduct fluorescence observation on rock thin sections and compare the abundance and type of organic matter in the surrounding rocks near the calcite and those far from the calcite in the same sample; focus on the location of calcite veins and observe and photograph the type and abundance characteristics of organic matter in the surrounding rocks near the calcite veins and those far from the calcite veins.

[0076] (4) Based on the observation of rock thin sections, in situ trace element analysis was carried out on the observed rock thin sections. The main test objects were the calcite veins in different samples, the surrounding rocks adjacent to the calcite veins, and the surrounding rocks far away from the calcite veins.

[0077] (5) Comprehensive identification method of hydrothermal calcite and hot water calcite

[0078] According to the above identification principle, firstly, the standardized plates of in-situ rare earth element chondrites of different samples are drawn. ① Visualized fluorescence thin section observation: When it is observed that there is no difference in lithology and organic matter abundance between the surrounding rocks close to and far from the calcite veins ( Figure 3 Figures a and b), for example, Figure 3 The middle a picture is mainly composed of layered algae. Figure 3 Figure b in the middle is dominated by structural algae bodies, and the degree of organic matter development is quite high. It can be preliminarily determined that this calcite is hydrothermal deposited calcite, because the formation of hydrothermal deposited calcite is after the surrounding rock, which has no effect on the abundance and source of organic matter in the shale; and it is observed that the abundance of organic matter in the surrounding rock near the calcite vein is significantly higher than that in the surrounding rock far away from the calcite vein, so it can be preliminarily determined that this calcite is hydrothermal deposited calcite, for example: Figure 3 Figure e: 3685.73m of bedding vein calcite in Well X1 Figure 3 In the middle f figure, the vein calcite at 3702.67m in the X1 well is much richer in organic matter near the calcite vein than far away from the calcite vein. This is because when the hydrothermal fluid enters the water body, it will affect the chemical properties of the sedimentary water body within a certain sedimentation period, thereby affecting the type and degree of organic matter development. ② The distribution characteristics of rare earth elements between the calcite vein and the surrounding rock: First, compare the differences between the calcite vein and the surrounding rock in different samples. If the abundance of rare earth elements in the calcite vein is significantly higher than that in the adjacent surrounding rock, it indicates that the formation of calcite is related to hydrothermal fluids, because the rare earth elements of calcite formed by hydrothermal fluids have not experienced dilution due to transportation and deposition, so their concentration is relatively high. In addition, compared with hot water calcite, the concentration of rare earth elements in hydrothermal calcite is higher because it has not entered the water body, so the element concentration is equivalent to that of the original hydrothermal fluid, such as Figure 3 Figure c and Figure 3 The concentration of rare earth elements in Figure d is higher than Figure 3 The g graph and Figure 3 In addition, as mentioned above, the formation of hydrothermal calcite will not affect the surrounding rock, so the concentration and distribution pattern of rare earth elements in the surrounding rock near the calcite and far away from the calcite vein will not be different, such as Figure 3 Figure C and Figure 3As shown in Figure d, hydrothermal calcite will affect the deposition of surrounding rocks within a certain range, so the concentration and distribution characteristics of rare earth elements near the calcite vein should be between the calcite vein and the surrounding rock far away from the calcite vein, such as Figure 3 Chinese G chart and Figure 3 As shown in Figure h.

[0079] In summary, the organic petrology of rock thin sections and in-situ major and trace element analysis techniques can be used to comprehensively judge the formation patterns of different calcite veins and trace the hydrothermal activity patterns, which is conducive to improving the scientific nature of sample selection when studying the effects of hydrothermal activity on organic matter enrichment in source rocks.

[0080] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A method for identifying hydrothermal calcite and hydrothermal calcite, characterized in that: The method comprises: Sample thin sections were made from calcite samples of the same layer and different occurrences; Organic petrology analysis was used to determine the type and abundance characteristics of organic matter in each sample thin section; Elemental geochemical analysis was used to determine the rare earth element data of each sample thin section; The deposition mode of the sample slice is determined according to the organic matter type and abundance characteristics of the sample slice and the rare earth element data; wherein the deposition mode includes: hot water deposition mode and hydrothermal deposition mode.

2. The method for identifying hot water calcite and hydrothermal calcite according to claim 1, characterized in that: Thin sections were made from calcite samples of the same layer and different occurrences, including: The cathodoluminescence method is used to determine the period of each calcite sample in the same layer and different occurrences. Sample thin sections were made from calcite samples of the same period.

3. The method for identifying hot water calcite and hydrothermal calcite according to claim 1, characterized in that: Calcite samples of different occurrences include translaminar calcite samples and bedding-parallel calcite samples.

4. The method for identifying hot water calcite and hydrothermal calcite according to claim 1, characterized in that: The sample slices include: a calcite vein sample slice, a first calcite surrounding rock sample slice and a second calcite surrounding rock sample slice.

5. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 1, characterized in that: The thickness of the sample slice was 0.04 mm, excluding the cover glass.

6. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 1, characterized in that: Organic petrology analysis is used to determine the type and abundance characteristics of organic matter in each sample thin section, including: Fluorescence thin section observation was performed on the sample slices to determine the organic matter type and abundance characteristics of each sample slice.

7. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 1, characterized in that: Using elemental geochemical analysis, rare earth element data of each sample slice were determined, including: In-situ micro-area trace element analysis is performed on different sample slices to determine the rare earth element data of each sample slice.

8. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 1, characterized in that: After determining the rare earth element data of each sample thin section by element geochemical analysis, the method further comprises: Performing chondrite standardization on the rare earth element data to obtain standardized rare earth element data; The rare earth element distribution characteristic curve is established using the standardized rare earth element data.

9. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 6, characterized in that: The process of determining the formation mode of the sample slice according to the organic matter type and abundance characteristics of the sample slice is as follows: If the first sample thin section and the second sample thin section have the same organic matter type or the same abundance characteristics, it is determined that the calcite vein sample thin section is a hydrothermal deposition model; If the first sample thin section and the second sample thin section have different organic matter types or different abundance characteristics, it is determined that the calcite vein sample thin section is a hydrothermal deposition model.

10. The method for identifying hydrothermal calcite and hydrothermal calcite according to claim 8, characterized in that: The process of determining the formation mode of the sample slice based on the rare earth element data is as follows: If the rare earth element concentration of the calcite vein sample thin section is greater than the rare earth element concentration of the first sample thin section and the rare earth element concentration of the second sample thin section, and the rare earth element distribution characteristic curve of the first sample thin section and the distribution characteristic curve of the second sample thin section have the same characteristics, then the calcite vein sample thin section is in hydrothermal deposition mode; If the rare earth element concentration of the calcite vein is greater than the rare earth element concentration of the first sample thin slice, and the rare earth element distribution characteristic curve of the first sample thin slice is different from the rare earth element distribution characteristic curve of the second sample thin slice, then the calcite vein sample thin slice is a hot water deposition mode.

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