Method for estimating content of valance-derived volatile components

Abstract

The invention provides a mantle source volatile component content estimation method, and belongs to the technical field of rare gas geochemical research. The estimation method comprises the following steps: acquiring sampling data of a target area; dividing the target area into the center, the middle part and the outer part of a structure-thermal response area according to the sequence of the carbon dioxide content of the non-hydrocarbon gas in the associated natural gas from large to small; respectively calculating the curtain-source volatile component source carbon dioxide specific gravity of each region; and calculating the content of the curtain-source volatile component in the target area according to the specific gravity of the carbon dioxide source of the curtain-source volatile component and the content of the carbon dioxide in the non-hydrocarbon gas in the associated natural gas in the corresponding area. Different methods are adopted for different carbon dioxide content areas to calculate the carbon dioxide proportion of the curtain source volatile component source, and the accuracy of estimating the curtain source volatile component content is effectively improved. Therefore, the migration range of the mantle-source volatile component can be more accurately determined, the exploration range is accurately delimited for developing helium and hydrogen strategic resources in an oil and gas field, and the exploration risk is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of rare gas geochemistry research, and particularly relates to a method for estimating the content of mantle-derived volatiles in tectonic-thermal response zones. Background Art

[0002] Mantle-derived volatiles are volatile substances released from the Earth's interior mantle, mainly present in the central regions of tectonic thermal events. Their components are mainly carbon dioxide and nitrogen, and are closely related to helium and hydrogen. Among these volatiles, carbon dioxide is not only the core component of deep mantle-derived volatiles but also plays a key role in its migration process.

[0003] In the deep mantle, carbon dioxide can coexist with helium and hydrogen. Driven by geological tectonic activities, high-concentration mantle-derived carbon dioxide, as the dominant carrier, carries helium and hydrogen to form multiphase seepage or gas-cap phase and migrates upward through channels such as faults. During the migration process, as the content of mantle-derived carbon dioxide decreases, the migration system transitions to a CO2-N2 mixed carrier phase; when the signal of mantle-derived carbon dioxide completely disappears, nitrogen becomes the single carrier gas and continues to affect the migration of helium and hydrogen. During this period, the dissolution and mineralization of carbon dioxide have an important impact on the enrichment of helium and hydrogen. For example, in the oil and gas-bearing basins in eastern China, the formation of mantle-derived carbon dioxide gas reservoirs is closely related to the enrichment of helium. The dissolution and mineralization of carbon dioxide increase the concentration of helium in the gas phase, thus promoting the enrichment of helium and being beneficial to the exploration and development of oil and gas fields.

[0004] Studying the carbon isotope behavior and evolution mechanism during the migration of mantle-derived volatiles is of great significance. Especially in areas significantly affected by mantle-derived fluids such as deep large faults or diapirism, it not only helps to deeply understand the geochemical characteristics of natural gas but also helps to identify the potential sources of helium and hydrogen, can provide important clues for the formation and enrichment of helium and hydrogen, provide important scientific basis for the exploration of helium and hydrogen, reduce exploration risks, and promote the development and utilization of unconventional energy resources. Summary of the Invention

[0005] Based on the above background, the purpose of this patent is to propose a method for estimating the content of mantle-derived volatiles, which can accurately characterize the content of mantle-derived volatiles for oil and gas fields under the geological tectonic background with tectonic-thermal response zones such as deep large faults, volcanoes, and diapir structures, and provide more accurate data support for natural gas geochemistry research and exploration.

[0006] To achieve the above purpose, the solution adopted by the present invention is: A method for estimating the content of mantle-derived volatiles, comprising the following steps:

[0007] S100. Obtain the sampling data of the target area, where the target area is a tectonic-thermal response area, and the sampling data includes the helium-3 content, the carbon isotope value, and the non-hydrocarbon gas carbon dioxide content in the associated natural gas;

[0008] S200. Divide the target area into the center of the tectonic-thermal response area, the middle part of the tectonic-thermal response area, and the outer part of the tectonic-thermal response area in the order of decreasing non-hydrocarbon gas carbon dioxide content in the associated natural gas;

[0009] S300. Calculate the proportion of mantle-derived volatile-source carbon dioxide in the center of the tectonic-thermal response area, the middle part of the tectonic-thermal response area, and the outer part of the tectonic-thermal response area respectively;

[0010] S400. Calculate the mantle-derived volatile content of the target area based on the proportion of mantle-derived volatile-source carbon dioxide and the non-hydrocarbon gas carbon dioxide content in the associated natural gas of the corresponding area.

[0011] Further, the non-hydrocarbon gas carbon dioxide content in the associated natural gas in the center of the tectonic-thermal response area > 50%; the non-hydrocarbon gas carbon dioxide content in the associated natural gas in the middle part of the tectonic-thermal response area is 5% - 50%; the non-hydrocarbon gas carbon dioxide content in the associated natural gas in the outer part of the tectonic-thermal response area < 5%.

[0012] Further, calculate the proportion of mantle-derived volatile-source carbon dioxide in the outer part of the tectonic-thermal response area based on the following formula:

[0013] (C / A) MEA = α / f1 VOL + β / f1 DEC + γ / f1 DIC + δ / f1 EVO + ∈ / f1 DOC (1)

[0014] (B / C) MEA = α / f2 VOL + β / f2 DEC + γ / f2 DIC + ε / f2 EVO + ∈ / f2 DOC (2)

[0015]

[0016] β = σx (4)

[0017] γ = σ(1 - x) (5)

[0018]

[0019] ε = τy (7)

[0020] ∈ = τ(1 - y) (8)

[0021] σ + τ = 1 - α (9)

[0022] Wherein, A is the standardized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value;

[0023] VOL, DEC, DIC, EVO, and DOC respectively refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, dissolved inorganic carbon DIC of basement carbonate minerals, release of organic matter thermal evolution, and dissolved organic carbon DOC in shallow fluids;

[0024] α, β, γ, ε, ∈ respectively refer to the proportion of carbon dioxide from mantle-derived volatiles, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, the proportion of carbon dioxide from dissolved inorganic carbon DIC of basement carbonate minerals, the proportion of carbon dioxide from release of organic matter thermal evolution, and the proportion of carbon dioxide from dissolved organic carbon DOC in shallow fluids. σ and τ are respectively the proportion of carbon dioxide from inorganic sources and the proportion of carbon dioxide from organic sources; x and y are the set normalization variables;

[0025] f1 VOL 、f1 DEC 、f1 DIC 、f1 EVO and f1 DOC have values of -0.15‰, 0.5‰, -0.5‰, -0.029‰, and -0.025‰ respectively; f2 VOL 、f2 DEC 、f2 DIC 、f2 EVO and f2 DOC have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 、0.8×10 13 、1.2×10 13 .

[0026] Furthermore, the proportion of carbon dioxide from mantle-derived volatiles in the middle of the tectono-thermal response zone is calculated based on the following formula:

[0027] (C / A) MEA = α / f3 VOL + β / f3 DEC + γ / f3 DIC + ε / f3 EVO (10)

[0028] (B / C) MEA = α / f4 VOL + β / f4DEC +γ / f4 DIC +ε / f4 EVO (11)

[0029]

[0030] β = σx (13)

[0031] γ = σ(1 - x) (14)

[0032] σ + ε = 1 - α (15)

[0033] Wherein, A is the standardized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value;

[0034] VOL, DEC, DIC, and EVO respectively refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, dissolution of inorganic carbon DIC from basement carbonate minerals, and release of organic matter thermal evolution;

[0035] α, β, γ, and ε respectively refer to the proportion of carbon dioxide from mantle-derived volatiles, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, the proportion of carbon dioxide from dissolution of inorganic carbon DIC from basement carbonate minerals, and the proportion of carbon dioxide from release of organic matter thermal evolution. σ is the proportion of carbon dioxide from inorganic sources; x is the set normalization variable; f3 VOL 、f3 DEC 、f3 DIC and f3 EVO have values of -0.15‰, 0.33‰, -0.5‰, and -0.067‰ respectively; f4 VOL 、f4 DEC 、f4 DIC and f4 EVO have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 、0.8×10 13 .

[0036] Furthermore, the proportion of carbon dioxide from mantle-derived volatiles at the center of the tectono-thermal response zone is calculated based on the following formula:

[0037] (V / A) MEA = α / f5 VOL + β / f5 DEC + γ / f5 DIC (16)

[0038] (B / C) MEA = α / f6 VOL + β / f6 DEC + γ / f6DIC (17)

[0039] β + γ = 1 - α (18)

[0040] Wherein, A is the normalized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value;

[0041] VOL, DEC, and DIC respectively refer to mantle-derived volatile components, thermal decomposition of crustal carbonate minerals, and dissolved inorganic carbon DIC of basement carbonate minerals;

[0042] α, β, and γ respectively refer to the proportion of carbon dioxide from mantle-derived volatile components, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, and the proportion of carbon dioxide from dissolved inorganic carbon DIC of basement carbonate minerals;

[0043] f5 VOL 、f5 DEC and f5 DIC have values of -0.15‰, 0.5‰, and -0.2‰ respectively; f6 VOL 、f6 DEC and f6 DIC have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 .

[0044] Furthermore, the value range of ε is 0% to 50%.

[0045] Furthermore, the mantle-derived volatile component content is calculated based on the following formula:

[0046]

[0047] Wherein, α is the proportion of carbon dioxide from mantle-derived volatile components, C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas in the corresponding area, is the mantle-derived volatile component content.

[0048] The beneficial effects of the present invention are as follows:

[0049] Due to being close to the centers of tectonic heat events such as deep major faults and deep crustal diapirs, the carbon dioxide content is particularly high and directly surges upward in form. It diffuses outward through the "radiation effect" of the tectonic center, and the carbon dioxide content gradually decreases during this process. Therefore, the carbon dioxide content can be used to characterize the relative distance from the center of the tectonic heat event to the shallow surface. For oil and gas fields with deep major faults or diapiric structures, the present invention creatively utilizes the above phenomenon, divides the exploration target area into the center of the tectonic-thermal response zone, the middle of the tectonic-thermal response zone, and the outside of the tectonic-thermal response zone, and adopts different methods to calculate the proportion of carbon dioxide from mantle-derived volatiles in different regions, effectively improving the accuracy of the estimation of the content of mantle-derived volatiles. Thus, the migration range of mantle-derived volatiles can be determined more accurately, accurately delimit the exploration range for the strategic resources of helium and hydrogen in oil and gas field development, and reduce the exploration risk.

[0050] The present invention further proposes to divide the area where the carbon dioxide content in non-hydrocarbon gas > 50% into the center of the tectonic-thermal response zone, the area where the carbon dioxide content in non-hydrocarbon gas is 5% - 50% into the middle of the tectonic-thermal response zone, and the area where the carbon dioxide content in non-hydrocarbon gas < 5% into the outside of the tectonic-thermal response zone. By setting conditions in stages to calculate the content of mantle-derived volatiles, the calculation efficiency can be improved by combining Matlab programming at the same time. Description of the Drawings

[0051] Figure 1 It is a statistical chart of the content of mantle-derived volatiles of each typical well in Gas Field A;

[0052] Figure 2 It is a distribution map of the planar positions of each typical well in Gas Field A; Detailed Embodiments

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the technical solutions of the present application. Based on the embodiments recorded in this application document, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope protected by the technical solutions of the present application.

[0054] Embodiment:

[0055] A method for estimating the content of mantle-derived volatiles under the geological structure background of tectonic-thermal response zones such as deep major faults and diapiric structures, comprising the following steps:

[0056] Step 1: Obtain the sampling data of the target area, which is the tectonic-thermal response area. The sampling data includes the natural gas geochemical related information of the target area, specifically including the helium content and the helium isotope content (such as the helium-3 content), the carbon isotope value, and the content of non-hydrocarbon gas carbon dioxide in the associated natural gas, etc. In this embodiment, a typical well in Gas Field A with tectonic thermal events is selected for implementation, and Gas Field A is the target area.

[0057] Step 2: Divide the target area into 3 categories according to the content of non-hydrocarbon gas carbon dioxide in the associated natural gas, which are: the center of the tectonic-thermal response area, where the content of carbon dioxide in the non-hydrocarbon gas > 50%. The middle part of the tectonic-thermal response area, where the content of carbon dioxide in the non-hydrocarbon gas is 5% - 50%. The outside of the tectonic-thermal response area, where the content of CO2 in the non-hydrocarbon gas < 5%.

[0058] Step 3: When in the outside of the tectonic-thermal response area and the content of CO2 in the non-hydrocarbon gas < 5%, the proportion of carbon dioxide from mantle-derived volatiles is calculated according to the following formula:

[0059] (C / A) MEA = α / f1 VOL + β / f1 DEC + γ / f1 DIC + ε / f1 EVO + ∈ / f1 DOC (1)

[0060] (B / C) MEA = α / f2 VOL + β / f2 DEC + γ / f2 DIC + ε / f2 EVO + ∈ / f2 DOC (2)

[0061]

[0062] β = σx (4)

[0063] γ = σ(1 - x) (5)

[0064]

[0065] ε = τy (7)

[0066] ∈ = τ(1 - y) (8)

[0067] σ + τ = 1 - α (9)

[0068] In the above formula, A is the standardized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value; VOL, DEC, DIC, EVO, and DOC respectively refer to mantle-derived volatile components, thermal decomposition of crustal carbonate minerals, dissolved inorganic carbon DIC of basement carbonate minerals, release of organic matter thermal evolution, and dissolved organic carbon DOC in shallow fluids; α, β, γ, ε, and ∈ respectively refer to the proportion of carbon dioxide from mantle-derived volatile components, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, the proportion of carbon dioxide from dissolved inorganic carbon DIC of basement carbonate minerals, the proportion of carbon dioxide from release of organic matter thermal evolution, and the proportion of carbon dioxide from dissolved organic carbon DOC in shallow fluids; σ and τ are respectively the proportion of carbon dioxide from inorganic sources and the proportion of carbon dioxide from organic sources; x and y are the set normalization variables; f1 VOL 、f1 DEC 、f1 DIC 、f1 EVO and f1 DOC have values of -0.15‰, 0.5‰, -0.5‰, -0.029‰, and -0.025‰ respectively; f2 VOL 、f2 DEC 、f2 DIC 、f2 EVO and f2 DOC have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 、0.8×10 13 、1.2×10 13 . To ensure the accuracy and rationality of the final result, the ε value is restricted to 0% - 50%.

[0069] When in the middle of the tectono-thermal response zone and the carbon dioxide content in the non-hydrocarbon gas is 5% - 50%, the proportion of carbon dioxide from mantle-derived volatile components is calculated according to the following formula:

[0070] (C / A) MEA =α / f3 VOL +β / f3 DEC +γ / f3 DIC +ε / f3 EVO (10)

[0071] (B / C) MEA =α / f4 VOL +β / f4 DEC +γ / f4 DIC +ε / f4 EVO (11)

[0072]

[0073] β = σx (13)

[0074] γ = σ(1 - x) (14)

[0075] σ + ε = 1 - α (15)

[0076] In the above equations, A is the normalized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value. VOL, DEC, DIC, and EVO refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, dissolved inorganic carbon DIC from basal carbonate minerals, and organic matter thermal evolution release, respectively. α, β, γ, and ε refer to the proportion of carbon dioxide from mantle-derived volatiles, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, the proportion of carbon dioxide from dissolved inorganic carbon DIC of basal carbonate minerals, and the proportion of carbon dioxide from organic matter thermal evolution release, respectively. σ is the proportion of carbon dioxide from inorganic sources; x is the set normalization variable; f3 VOL 、f3 DEC 、f3 DIC and f3 EVO have values of -0.15‰, 0.33‰, -0.5‰, and -0.067‰, respectively; f4 VOL 、f4 DEC 、f4 dIC and f4 EVO have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 、0.8×10 13 .

[0077] When in the center of the tectonic-thermal response zone and the carbon dioxide content in the non-hydrocarbon gas > 50%, the proportion of carbon dioxide from mantle-derived volatiles is calculated according to the following formula:

[0078] (C / A) MEA = α / f5 VOL + β / f5 DEC + γ / f5 DIC (16)

[0079] (B / C) MEA = α / f6 VOL + β / f6 DEC + γ / f6 DIC (17)

[0080] β + γ = 1 - α (18)

[0081] Where A is the standardized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value. VOL, DEC, and DIC refer to mantle-derived volatiles, crust-derived carbonate mineral thermal decomposition, and basement carbonate mineral dissolved inorganic carbon (DIC), respectively. α, β, and γ refer to the carbon dioxide fractions derived from mantle-derived volatiles, crust-derived carbonate mineral thermal decomposition, and basement carbonate mineral dissolved inorganic carbon (DIC), respectively. f5 VOL 、f5 DEC and f5 DIC The values of f6 are -0.15‰, 0.5‰ and -0.2‰ respectively; VOL 、f6 DEC and f6 DIC The values are 1.5×10 9 , 0.9×10 13 , 1.5×10 13 .

[0082] The fourth step is to write a code based on the above calculation formula in MATLAB software and link it to the database to calculate the carbon dioxide proportion of mantle-derived volatiles in the center, middle, and outer parts of the tectonic-thermal response area. The execution steps are as follows:

[0083] (1) Use MATLAB's Database Toolbox to connect to a database (such as MySQL, SQLite, etc.) that stores data, and use SQL query statements to extract the non-hydrocarbon carbon dioxide content, helium-3 content, and standardized carbon isotope values in the associated natural gas of different well names. The specific operations include:

[0084] %Connect to database

[0085] conn=database('database_name','username','password','Vendor','Server','Port');

[0086] %Query data

[0087] sqlquery='SELECT well_name,CO2,He3,delta13C FROM carbon_data';

[0088] data=fetch(conn,sqlquery);

[0089] % Disconnect

[0090] close(conn);

[0091] (2) Divide the data into three cases according to the content of non-hydrocarbon gas carbon dioxide in associated natural gas: CO2 > 50%, CO2 between 5% and 50%, and CO2 < 5%. Use logical indexing to extract the data subsets in each case. The specific operations include:

[0092]

[0093] (3) Define constants and symbolic variables, use loops to solve the equations, and select different equations to solve according to the value of C to obtain the proportion of carbon dioxide from mantle-derived volatiles in each region. Specifically, the solve function can be used to solve the equations, and the disp function can be used to output the solution arrays of each variable. The specific operations include:

[0094]

[0095]

[0096] Step 5, calculate the content of mantle-derived volatiles:

[0097]

[0098] In the formula, α is the proportion of carbon dioxide from mantle-derived volatiles, and C is the content of non-hydrocarbon gas carbon dioxide in the associated natural gas in the corresponding region. is the content of mantle-derived volatiles. Since the existing technology cannot accurately calculate the content of mantle-derived volatiles, and carbon dioxide is the main component of mantle-derived volatiles, the content of carbon dioxide from mantle-derived volatiles can be approximately used to replace the content of mantle-derived volatiles.

[0099] Step 6, based on the quantitative calculation results of the content of mantle-derived volatiles, combined with the well plane position and sampling depth in the tectonic-thermal response area of the oil and gas field, analyze the spatial distribution of mantle-derived volatiles and the sweet spot area.

[0100] The sampling data and calculation results involved in this embodiment are shown in Table 1.

[0101] Table 1. Statistical table of sample information, test data and Mtalab calculation results of Gas Field A

[0102]

[0103]

[0104] In Table 1, δ 13 C CO2 is the standardized carbon isotope value, and CO2 is the content of non-hydrocarbon gas carbon dioxide in the associated natural gas.

[0105] The calculation results of the content of mantle-derived volatiles are as Figure 1As shown in the figure, the results show that in the natural gas of the typical wells in Gas Field A, the content of mantle-derived volatile components ranges from 0.006% to 6.345%, and the histogram presents multiple peaks. Combining the plane positions of the typical wells in the oil and gas fields and the verification and analysis of the sampling depths, the calculation results of the method provided by the present invention can accurately reflect the migration range and spatial distribution of the mantle-derived volatile components in the oil and gas fields (such as Figure 2 shown). Among them, Wells A3, A7, A13, and A18 have relatively high contents of mantle-derived volatile components compared with other wells, and can be used as key exploration "sweet spots" for deep helium and hydrogen, reducing exploration risks and improving production efficiency.

Claims

1. A method for estimating the content of mantle-derived volatile components, characterized in that: It includes the following steps: S100. Obtain the sampling data of the target area, where the target area is a tectonic-thermal response area, and the sampling data includes the helium-3 content, carbon isotope value, and the content of non-hydrocarbon gas carbon dioxide in the associated natural gas; S200. Divide the target area into the center of the tectonic-thermal response area, the middle part of the tectonic-thermal response area, and the outer part of the tectonic-thermal response area in the order of the content of non-hydrocarbon gas carbon dioxide in the associated natural gas from large to small; S300. Calculate the proportion of carbon dioxide from mantle-derived volatiles in the center of the tectonic-thermal response area, the middle part of the tectonic-thermal response area, and the outer part of the tectonic-thermal response area respectively; S400. Calculate the content of mantle-derived volatiles in the target area based on the proportion of carbon dioxide from mantle-derived volatiles and the content of non-hydrocarbon gas carbon dioxide in the associated natural gas in the corresponding area.

2. The method for estimating the mantle-derived volatile content according to claim 1, wherein: The content of non-hydrocarbon gas carbon dioxide in the associated natural gas in the center of the tectonic-thermal response area > 50%; the content of non-hydrocarbon gas carbon dioxide in the associated natural gas in the middle part of the tectonic-thermal response area is 5% - 50%; the content of non-hydrocarbon gas carbon dioxide in the associated natural gas in the outer part of the tectonic-thermal response area < 5%.

3. The method for estimating the content of mantle-derived volatiles according to claim 2, characterized in that: The proportion of carbon dioxide from mantle-derived volatiles in the outer part of the tectonic-thermal response area is calculated based on the following formula: (C / A) MEA = α / f1 VOL + β / f1 DEC + γ / f1 DIC + ε / f1 EVO + ∈ / f1 DOC (1) (B / C) MEA = α / f2 VOL + β / f2 DEC + γ / f2 DIC + ε / f2 EVO + ∈ / f2 DOC (2) β = σx (4) γ = σ(1 - x) (5) ε = τy (7) ∈ = τ(1 - y) (8) σ + τ = 1 - α (9) where A is the normalized carbon isotope value, B is the helium-3 content, C is the content of non-hydrocarbon gas carbon dioxide in the associated natural gas; the subscript MEA represents the sample measurement value; VOL, DEC, DIC, EVO, and DOC respectively refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, dissolved inorganic carbon DIC of basement carbonate minerals, release of organic matter thermal evolution, and dissolved organic carbon DOC in shallow fluids; α, β, γ, ε, ∈ respectively refer to the proportion of carbon dioxide from mantle-derived volatiles, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, the proportion of carbon dioxide from dissolved inorganic carbon DIC of basement carbonate minerals, the proportion of carbon dioxide from release of organic matter thermal evolution, and the proportion of carbon dioxide from dissolved organic carbon DOC in shallow fluids. σ and τ are respectively the proportion of carbon dioxide from inorganic sources and the proportion of carbon dioxide from organic sources; x and y are set normalization variables; f1 VOL 、f1 DEC 、f1 DIC 、f1 EVO and F1 DOC The values of f2 were -0.15‰, 0.5‰, -0.5‰, -0.029‰ and -0.025‰ respectively; VOL 、f2 DEC 、f2 DIC 、f2 EVO and f2 DOC The values are 1.5×10 9 , 0.9×10 13 , 1.5×10 13 , 0.8×10 13 , 1.2×10 13 .

4. The method for estimating the content of mantle-derived volatiles according to claim 2, wherein: The proportion of carbon dioxide from mantle-derived volatiles in the middle part of the tectonic-thermal response area is calculated based on the following formula: (C / A) MEA = α / f3 VOL + β / f3 DEC + γ / f3 DIC + ε / f3 EVO (10) (B / C) MEA = α / f4 VOL + β / f4 DEC + γ / f4 DIC + ε / f4 EVO (11) β = σx (13) β = σ(1 - x) (14) σ + ε = 1 - α (15) where A is the normalized carbon isotope value, B is the helium-3 content, C is the content of non-hydrocarbon gas carbon dioxide in the associated natural gas; the subscript MEA represents the sample measurement value; VOL, DEC, DIC, and EVO respectively refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, dissolved inorganic carbon DIC of basement carbonate minerals, and release of organic matter thermal evolution; α, β, γ, and ε refer to the proportions of carbon dioxide from mantle-derived volatiles, carbon dioxide from thermal decomposition of crustal carbonate minerals, carbon dioxide from dissolved inorganic carbon (DIC) of basal carbonate minerals, and carbon dioxide from the release of organic matter during thermal evolution, respectively; σ is the proportion of carbon dioxide from inorganic sources; x is the set normalization variable; f3 VOL , f3 DEC , f3 DIC and f3 EVO have values of -0.15‰, 0.33‰, -0.5‰, and -0.067‰, respectively; f4 VOL , f4 DEC , f4 DIC and f4 EVO have values of 1.5×10 9 , 0.9×10 13 , 1.5×10 13 , 0.8×10 13 .

5. The mantle-derived volatile content estimation method according to claim 2, wherein: The proportion of carbon dioxide from mantle-derived volatiles in the center of the tectonic-thermal response area is calculated based on the following formula: (C / A) MEA = α / f5 VOL + β / f5 DEC + γ / f5 DIC (16) (B / V) MEA = α / f6 VOL + β / f6 DEC + γ / f6 DIC (17) β + γ = 1 - α (18) Wherein, A is the standardized carbon isotope value, B is the helium-3 content, and C is the non-hydrocarbon gas carbon dioxide content in the associated natural gas; the subscript MEA represents the sample measurement value; VOL, DEC, and DIC respectively refer to mantle-derived volatiles, thermal decomposition of crustal carbonate minerals, and dissolved inorganic carbon DIC of basement carbonate minerals; α, β, and γ respectively refer to the proportion of carbon dioxide from mantle-derived volatiles, the proportion of carbon dioxide from thermal decomposition of crustal carbonate minerals, and the proportion of carbon dioxide from dissolved inorganic carbon DIC of basement carbonate minerals; f5 VOL 、f5 DEC and f5 DIC have values of -0.15‰, 0.5‰, and -0.2‰ respectively; f6 VOL 、f6 DEC and f6 DIC have values of 1.5×10 9 、0.9×10 13 、1.5×10 13 .

6. The method for estimating the mantle-derived volatile content according to claim 3, wherein: The value range of ε is 0% to 50%.

7. The method for estimating the mantle-derived volatile content according to any one of claims 3-6, characterized in that: The mantle-derived volatile content is calculated based on the following formula: Among them, α is the proportion of carbon dioxide from mantle-derived volatiles, and C is the carbon dioxide content in the non-hydrocarbon gas in the associated natural gas in the corresponding area. It is the content of mantle-derived volatiles.

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