Natural gas source comparison method and system

Abstract

The invention belongs to the technical field of natural gas exploration, and discloses a natural gas source comparison method and system, and the method comprises the steps: obtaining a natural gas sample of a target gas reservoir in a deep-ultra-deep layer series research area; determining a measured value of Ar component abundance and a measured value of 40Ar / 36Ar isotope in the air standard sample; determining an Ar component abundance measurement value and a 40Ar / 36Ar isotope measurement value in the natural gas sample; determining an Ar component abundance correction value in the natural gas sample; determining the radiogenesis 40Ar abundance value of the natural gas sample; and determining the times of hydrocarbon source rocks of natural gas in the target gas reservoir and main hydrocarbon source rocks. According to the method, an existing natural gas cause identification and gas source comparison technical index system is enriched and perfected, an effective method and technical means can be provided for deep-ultra-deep high-evolution complex natural gas cause identification and gas source comparison, and an important technical support is provided for guiding natural gas exploration.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas exploration, and in particular relates to a natural gas source comparison method and system. Background Art

[0002] As the current natural gas exploration and development continues to expand from medium and shallow layers to deep and ultra-deep ancient highly evolved strata, the exploration objects are becoming increasingly complex and the difficulty is increasing, and the difficulty and risk of exploration and discovery are also increasing.

[0003] At present, natural gas genesis identification and gas source comparison mainly use a variety of methods such as natural gas components and isotopes, light hydrocarbon components and isotopes, biomarkers in condensate and reservoir asphalt, non-hydrocarbon gas components and isotopes. As the current natural gas exploration and development continues to expand from medium and shallow layers to deep and ultra-deep ancient high-evolution strata, the exploration objects are becoming increasingly complex and the difficulty is increasing. The difficulty and risk of exploration and discovery are also increasing. Conventional single-origin gas reservoirs are increasingly rare, and deep high-evolution complex multi-source gas reservoirs are increasing. In particular, deep-ultra-deep natural gas is mostly highly evolved high-overmature natural gas, with methane as the main component, extremely low ethane and heavier hydrocarbon content, high dryness coefficient, and abnormal geochemical characteristics such as inversion or reversal of alkane gas carbon and hydrogen isotopes. There is less and less useful information available, and the genesis source is very complex. Conventional genesis identification and gas source comparison methods are difficult to identify, which restricts the determination of the genesis and source of deep-ultra-deep high-evolution complex natural gas, the determination of the main source rock strata, and the selection of exploration directions.

[0004] In summary, the current methods of natural gas genesis identification and gas source comparison provide little useful information in deep to ultra-deep ancient highly evolved strata, and are unable to complete the determination of the genesis and source of deep to ultra-deep highly evolved complex natural gas, or the identification and exploration of the main source rock strata. Summary of the invention

[0005] In view of the above problems, the present invention provides a natural gas source comparison method and system, which adopts the following technical solutions:

[0006] A natural gas source comparison method comprises the following steps: obtaining a natural gas sample from a target gas reservoir in a deep-ultra-deep high-evolution stratum research area; determining the measured value of the Ar component abundance in an air standard sample and 40 Ar / 36 Ar isotope measurement value; determine the Ar component abundance measurement value in natural gas samples and 40 Ar / 36 Ar isotope measurement value; determine the Ar component abundance correction value in the natural gas sample through the Ar component abundance correction coefficient of the air standard sample and the Ar component abundance measurement value in the natural gas sample; 40 Ar / 36The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value; based on the radioactive origin of natural gas samples 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

[0007] Furthermore, the measured value of the abundance of the Ar component in the air standard sample and 40 Ar / 36 The Ar isotope measurement includes the following steps:

[0008] Purify the air standard sample to obtain the rare gas in the air standard sample;

[0009] The abundance of the Ar component in the noble gas in the air standard sample is measured multiple times, and the average value is taken to obtain the measured value of the abundance of the Ar component in the air standard sample;

[0010] Multiple measurements of rare gases in air standards 40 Ar / 36 Ar isotope value, and take the average value to get the value of Ar in the air standard sample. 40 Ar / 36 Ar isotope measurements.

[0011] Furthermore, the method further comprises the following steps:

[0012] The Ar component abundance correction coefficient of the air standard sample is determined according to an average value of a plurality of Ar component abundance measurement values ​​in the air standard sample and a standard gas Ar component abundance correction value.

[0013] Furthermore, the method further comprises the following steps:

[0014] According to the multiple 40 Ar / 36 The average value of Ar isotope measurements and standard gas 40 Ar / 36 Actual value of Ar isotope, determine the air standard 40 Ar / 36 Ar isotope correction factor.

[0015] Furthermore, the abundance of Ar in natural gas samples was determined. 40 Ar / 36 The Ar isotope measurement includes the following steps:

[0016] Purify the natural gas sample to obtain the rare gas in the natural gas sample;

[0017] The abundance of the Ar component in the rare gas in the natural gas sample is measured multiple times, and the average value is taken to obtain the measured value of the abundance of the Ar component in the natural gas sample;

[0018] Multiple measurements of rare gases in natural gas samples 40 Ar / 36 Ar isotope value, and take the average value to get the value of Ar in natural gas sample. 40 Ar / 36 Ar isotope measurements.

[0019] Furthermore, according to the natural gas samples 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 The Ar abundance values ​​are as follows:

[0020] C 40 Ar*=C 40 Ar 校 ×( 40 Ar / 36 Ar 实 -295.5) / ( 40 Ar / 36 Ar 实 +1.188)

[0021] In the formula, C 40 Ar* represents the radioactive origin of the natural gas sample 40 Ar abundance, C 40 Ar 校 Indicates the abundance correction value of Ar component in natural gas sample, 40 Ar / 36 Ar 实 Indicates that natural gas samples 40 Ar / 36 Actual value of Ar isotope.

[0022] Furthermore, the known geological data of the target gas reservoir include the average porosity of the target gas reservoir, the average potassium content of the possible source rock series of the target gas reservoir, the average potassium content of the known source rock series in the known gas reservoirs in the study area, and the actual stratigraphic age of the known source rocks in the known gas reservoirs.

[0023] Furthermore, based on the radioactive origin of the natural gas samples 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock, including the following steps:

[0024] Based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radioactive origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the equilibrium compensation coefficient of the study area;

[0025] According to the radioactive origin of natural gas in the target gas reservoir 40 The Ar abundance value, the average potassium content of the known source rock series in the target gas reservoir, and the equilibrium compensation coefficient of the study area are used to estimate the age of the source rock of the natural gas in the target gas reservoir;

[0026] The estimated age of the source rock of the natural gas in the target gas reservoir is compared with the actual stratigraphic age of the source rock in the study area to determine the main source rock of the natural gas in the target gas reservoir.

[0027] Furthermore, based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radiogenic origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the balance compensation coefficient of the study area, as follows:

[0028]

[0029] In the formula, C 40 Ar* 平均 Indicates the radioactive origin of natural gas in known gas reservoirs 40 The average value of Ar abundance, [K] represents the average potassium content of known source rock series in known gas reservoirs, represents the average porosity of known gas reservoirs, M represents the balance compensation coefficient of the study area, and X K Indicates that in nature 40 K abundance, λ K express 40 K decays into 40 The decay constant of Ar, λ represents 40 K decays into 40 Ar and 40 The total decay constant of Ca, t represents the age of known source rocks in known gas reservoirs in the study area.

[0030] The present invention also provides a natural gas source comparison system, comprising:

[0031] Sampling container, used to obtain natural gas samples from target gas reservoirs in the deep-ultra-deep high-evolution strata study area;

[0032] A quadrupole mass spectrometer is used to determine the abundance of Ar components in air standards and natural gas samples;

[0033] Noble Gas Isotope Mass Spectrometer for determination of noble gas isotope mass in air standards and natural gas samples 40 Ar / 36 Ar isotope measurements;

[0034] The first calculation module is used to determine the Ar component abundance correction value in the natural gas sample by using the Ar component abundance correction coefficient of the air standard sample and the Ar component abundance measurement value in the natural gas sample;

[0035] The second calculation module is used to calculate the 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value;

[0036] The third calculation module is used to calculate the radiogenic origin of the natural gas sample. 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

[0037] Furthermore, the known geological data of the target gas reservoir include the average porosity of the target gas reservoir, the average potassium content of the possible source rock series of the target gas reservoir, the average potassium content of the known source rock series in the known gas reservoirs in the study area, and the actual stratigraphic age of the known source rocks in the known gas reservoirs.

[0038] Furthermore, the third computing module is specifically used for:

[0039] Based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radioactive origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the equilibrium compensation coefficient of the study area;

[0040] According to the radioactive origin of natural gas in the target gas reservoir 40 The Ar abundance value, the average potassium content of the known source rock series in the target gas reservoir, and the balance compensation coefficient of the study area are used to estimate the age of the source rock of the natural gas in the target gas reservoir;

[0041] The estimated age of the source rock of the natural gas in the target gas reservoir is compared with the actual stratigraphic age of the source rock in the study area to determine the main source rock of the natural gas in the target gas reservoir.

[0042] The beneficial effects of the invention: The invention enriches and improves the existing technical indicator system for natural gas genesis identification and gas source comparison, and can provide effective methods and technical means for deep-ultra-deep highly evolved complex natural gas genesis identification and gas source comparison, and provide important technical support for clarifying the genesis and source of deep-ultra-deep highly evolved complex natural gas, determining the main source rock strata and their contributions, and guiding deep-ultra-deep natural gas exploration.

[0043] Other features and advantages of the present invention will be described in the following description, and partly become obvious from the description, or be understood by implementing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 A schematic flow chart of a natural gas source comparison method according to an embodiment of the present invention is shown;

[0046] Figure 2 The radioactivity of several target gas reservoirs in a basin determined by the method of an embodiment of the present invention is shown. 40 Schematic diagram of Ar abundance values. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] It should be noted that the terms "first", "second", etc. in the present application are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0049] The present invention first briefly introduces the radioactive argon components:

[0050] Argon has three natural isotopes: 36 Ar, 38 Ar and 40Ar, the abundance of each isotope is 0.337%, 0.063%, 99.600%, respectively, among which, 40 Ar has an absolute advantage. 40 Ar is composed of 40 K decays to form, 40 K has two branch decay modes, produced by B decay 40 Ca, generated by electron capture 40 Ar. Radioactive origin of natural gas 40 Ar mainly comes from source rocks 40 The decay of K.

[0051] Based on the above theory, the abundance of radioactive argon components may provide necessary information for determining the origin and source of deep-ultra-deep highly evolved complex natural gas. Therefore, an embodiment of the present invention provides a natural gas source comparison method and system, which provides an effective technical means for the origin identification and gas source comparison of deep-ultra-deep highly evolved complex natural gas based on the abundance of radioactive argon components in natural gas.

[0052] like Figure 1 As shown, a natural gas source comparison method comprises the following steps:

[0053] S1. Obtain natural gas samples from the target gas reservoir in the deep-ultra-deep high-evolution strata study area through sampling containers.

[0054] For example, the sampling container may be a stainless steel high pressure cylinder with a double valve.

[0055] Step S1 is as follows: a stainless steel high-pressure cylinder with a double valve is used to collect natural gas samples from deep and ultra-deep high-evolution gas reservoirs. Before sampling, a mechanical pump is used to evacuate the stainless steel high-pressure cylinder until the vacuum reaches a set value (for example, the vacuum is 10 -1 During the sampling process, the natural gas in the target gas reservoir is used to repeatedly flush the stainless steel high-pressure cylinder 4 to 6 times for 5 to 10 minutes. When the gas pressure in the stainless steel high-pressure cylinder is between 3 and 6 MPa, sampling is stopped to obtain the natural gas sample of the target gas reservoir.

[0056] S2. Determine the measured value and abundance of Ar component in air standard sample by quadrupole mass spectrometer and noble gas isotope mass spectrometer 40 Ar / 36 The Ar isotope measurement includes the following steps:

[0057] S21. Connect the steel cylinder containing the air standard sample to the sample preparation device for rare gases in natural gas, and use the sample preparation device for rare gases pretreatment in natural gas to purify the active gases such as N2 and O2 other than the rare gases in the air standard sample to obtain the rare gases in the air standard sample.

[0058] S22. Send the noble gas in the air standard sample into a quadrupole mass spectrometer, and use the quadrupole mass spectrometer to measure the abundance of the Ar component. The measurement is performed three times and an average value is taken to obtain a measured value of the abundance of the Ar component in the air standard sample.

[0059] S23, sending the noble gas in the air standard sample into the noble gas isotope mass spectrometer, and using the noble gas isotope mass spectrometer to 40 Ar / 36 The Ar isotope value was measured 3 times and the average value was taken to obtain the value of Ar in the air standard sample. 40 Ar / 36 Ar isotope measurements.

[0060] S3. Determine the air standard sample Ar component abundance correction coefficient according to the average value of the measured values ​​of the multiple Ar component abundances in the air standard sample and the standard gas Ar component abundance correction value (fixed value 0.934%), as follows:

[0061] Repeat steps S21 and S22 for 6 times, calculate the average of the 6 measured values ​​of the Ar component abundance in the standard air samples, and determine the correction coefficient of the Ar component abundance in the standard air sample based on the standard gas Ar component abundance correction value and the average of the 6 measured values ​​of the Ar component abundance in the standard air samples.

[0062] S4, according to the air standard sample 40 Ar / 36 The average value of Ar isotope measurements and standard gas 40 Ar / 36 The actual value of Ar isotope (fixed value 295.5), determine the air standard 40 Ar / 36 Ar isotope correction factor is as follows:

[0063] Repeat steps S21 and S23 6 times to calculate the air standard sample 40 Ar / 36 The average value of Ar isotope measurement is based on the standard gas 40 Ar / 36 The actual value of Ar isotope and the six air standard samples 40 Ar / 36 The average value of Ar isotope measurements was determined by air standard 40 Ar / 36 Ar isotope correction factor.

[0064] S5. Determine the Ar component abundance measurement value and 40 Ar / 36 The Ar isotope measurement includes the following steps:

[0065] S51. Connect the sampling container (stainless steel high-pressure cylinder) containing the natural gas sample to the rare gas sample preparation device in the natural gas through a pressure reducing valve, and use the rare gas sample preparation device in the natural gas to purify the active gases in the natural gas except the rare gases, such as hydrocarbon gases such as CH4 and non-hydrocarbon gases such as CO2 and N2, so as to obtain the rare gases in the natural gas sample.

[0066] S52. Send the noble gas in the natural gas sample to a quadrupole mass spectrometer, use the quadrupole mass spectrometer to measure the abundance of the Ar component, repeat the measurement three times and take the measurement average to obtain the measured value of the abundance of the Ar component in the natural gas sample.

[0067] S53, sending the noble gas in the natural gas sample into the noble gas isotope mass spectrometer, and using the noble gas isotope mass spectrometer to 40 Ar / 36 The Ar isotope value was measured and repeated three times and the average value was taken to obtain the Ar isotope value in the natural gas sample. 40 Ar / 36 Ar isotope measurements.

[0068] S6. Determine the Ar component abundance correction value in the natural gas sample by using the Ar component abundance correction coefficient of the air standard sample and the measured value of the Ar component abundance in the natural gas sample, which is recorded as C 40 Ar 校 .

[0069] S7, through the air standard 40 Ar / 36 Ar isotope correction factor and the content of Ar in natural gas samples 40 Ar / 36 Ar isotope measurement to determine the content of Ar in natural gas samples 40 Ar / 36 The actual value of Ar isotope is denoted as 40 Ar / 36 Ar 实 .

[0070] S8. According to the natural gas sample 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value, denoted as C 40 Ar*, as follows:

[0071] C 40 Ar*=C 40 Ar 校 ×( 40 Ar / 36 Ar 实 -295.5) / (40 Ar / 36 Ar 实 +1.188) (1)

[0072] S9. Based on the radioactive origin of natural gas samples 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

[0073] Among them, the known geological data of the target gas reservoir include the average porosity of the known gas reservoir, the average potassium content of the possible source rock series of the target gas reservoir, the average potassium content of the known source rock series in the known gas reservoirs in the study area, and the actual stratigraphic age of the known source rocks in the known gas reservoirs.

[0074] For example, where practical conditions permit, sampling of natural gas from a target gas reservoir may involve source rock sampling, and analysis of the potassium content of the source rock or collection of potassium content data for source rock strata related to the target gas reservoir.

[0075] Step S9 is specifically as follows:

[0076] S91, based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir , the average potassium content [K] of known source rock series in known gas reservoirs, and the radiogenic origin of multiple natural gas samples in known gas reservoirs 40 The average value of Ar abundance is denoted as C 40 Ar* 平均 , determine the balance compensation coefficient M of the study area, as follows:

[0077]

[0078] In the formula, X K Indicates that in nature 40 K abundance is 1.167×10 -4 ; K express 40 K decays into 40 The decay constant of Ar is 5.81×10 -11 ; λ represents 40 K decays into 40 Ar and 40 The total decay constant of Ca is 5.543×10 -10 ; t represents the age of the source rocks of known gas reservoirs in the study area.

[0079] S92. Determine the radioactive origin of the natural gas in the target gas reservoir based on the actual stratigraphic age of the known source rocks in the known gas reservoirs, the average potassium content [K] of the known source rock series in the known gas reservoirs, and the equilibrium compensation coefficient M obtained for the study area. 40Ar abundance value, denoted as C 40 Ar*.

[0080] S93. Based on the radioactive origin of natural gas in the target gas reservoir 40 Ar abundance C 40 Ar*, the average potassium content of the known source rock series in the target gas reservoir [K], and the equilibrium compensation coefficient M of the study area, the age t of the source rock of the natural gas in the target gas reservoir is estimated by formula (3).

[0081]

[0082] S94. Compare the estimated age t of the source rock of the natural gas in the target gas reservoir with the actual stratigraphic age of the source rock existing in the study area to determine the main source rock of the natural gas in the target gas reservoir.

[0083] Based on the above natural gas source comparison method, the present invention also provides a natural gas source comparison system, including: a sampling container, a quadrupole mass spectrometer, a rare gas isotope mass spectrometer, a first calculation module, a second calculation module and a third calculation module.

[0084] Among them, the sampling container is used to obtain natural gas samples from the target gas reservoir in the deep-ultra-deep high-evolution stratum research area; the quadrupole mass spectrometer is used to determine the measured value of the Ar component abundance in the air standard sample and the natural gas sample; the noble gas isotope mass spectrometer is used to determine the 40 Ar / 36 Ar isotope measurement value; a first calculation module, used to determine the Ar component abundance correction value in the natural gas sample by using the Ar component abundance correction coefficient of the air standard sample and the Ar component abundance measurement value in the natural gas sample; a second calculation module, used to determine the Ar component abundance correction value in the natural gas sample according to the Ar component abundance correction coefficient in the natural gas sample. 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value; the third calculation module is used to calculate the radioactive origin of the natural gas sample 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

[0085] For example, the natural gas source comparison method and system of the present invention are used to determine the origin and source of natural gas and the main source rock formations of several target gas reservoirs in a basin, providing important technical support for guiding deep and ultra-deep natural gas exploration. The data finally obtained are shown in Table 1 and Figure 2 shown.

[0086] Table 1

[0087]

[0088] The natural gas source comparison method and system of the present invention, based on the abundance of radioactive Ar components in natural gas, enrich and improve the existing technical indicator system for natural gas origin identification and source comparison, and can provide effective methods and technical means for deep-ultra-deep highly evolved complex natural gas origin identification and source comparison. It has technical advantages in clarifying the origin and source of deep-ultra-deep highly evolved complex natural gas, determining the main source rock strata and their contributions, etc.

[0089] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A natural gas source comparison method, characterized in that: The following steps are involved: Obtain natural gas samples from target gas reservoirs in the deep-ultra-deep high-evolution strata study area; Determine the measured value of Ar component abundance in the air standard sample and 40 Ar / 36 Ar isotope measurements; Determine the Ar component abundance measurement value and 40 Ar / 36 Ar isotope measurements; The Ar component abundance correction value in the natural gas sample is determined by the Ar component abundance correction coefficient of the air standard sample and the Ar component abundance measurement value in the natural gas sample; According to the natural gas samples 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value; Based on the radioactive origin of natural gas samples 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

2. The natural gas source comparison method according to claim 1, characterized in that: Determine the measured value of Ar component abundance in the air standard sample and 40 Ar / 36 The Ar isotope measurement includes the following steps: Purify the air standard sample to obtain the rare gas in the air standard sample; The abundance of the Ar component in the noble gas in the air standard sample is measured multiple times, and the average value is taken to obtain the measured value of the abundance of the Ar component in the air standard sample; Multiple measurements of rare gases in air standards 40 Ar / 36 Ar isotope value, and take the average value to get the value of Ar in the air standard sample. 40 Ar / 36 Ar isotope measurements.

3. The natural gas source comparison method according to claim 1, characterized in that: The following steps are also included: The Ar component abundance correction coefficient of the air standard sample is determined according to an average value of a plurality of Ar component abundance measurement values ​​in the air standard sample and a standard gas Ar component abundance correction value.

4. The natural gas source comparison method according to claim 1, characterized in that: The following steps are also included: According to the multiple 40 Ar / 36 The average value of Ar isotope measurements and standard gas 40 Ar / 36 Actual value of Ar isotope, determine the air standard 40 Ar / 36 Ar isotope correction factor.

5. The natural gas source comparison method according to claim 1, characterized in that: Determine the Ar component abundance measurement value and 40 Ar / 36 The Ar isotope measurement includes the following steps: Purify the natural gas sample to obtain the rare gas in the natural gas sample; The abundance of the Ar component in the rare gas in the natural gas sample is measured multiple times, and the average value is taken to obtain the measured value of the abundance of the Ar component in the natural gas sample; Multiple measurements of rare gases in natural gas samples 40 Ar / 36 Ar isotope value, and take the average value to get the value of Ar in natural gas sample. 40 Ar / 36 Ar isotope measurements.

6. The natural gas source comparison method according to claim 1, characterized in that: According to the natural gas samples 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 The Ar abundance values ​​are as follows: C 40 On*=C 40 Ar 校 ×( 40 on / 36 Ar 实 -295.5) / ( 40 on / 36 Ar 实 +1.188) In the formula, C 40 Ar* represents the radioactive origin of the natural gas sample 40 Ar abundance, C 40 Ar 校 Indicates the abundance correction value of Ar component in natural gas sample, 40 Ar / 36 Ar 实 Indicates that natural gas samples 40 Ar / 36 Actual value of Ar isotope.

7. The natural gas source comparison method according to any one of claims 1 to 6, characterized in that: The known geological data of the target gas reservoir include the average porosity of the target gas reservoir, the average potassium content of the possible source rock series of the target gas reservoir, the average potassium content of the known source rock series in the known gas reservoirs in the study area, and the actual stratigraphic age of the known source rocks in the known gas reservoirs.

8. The natural gas source comparison method according to claim 7, characterized in that: Based on the radioactive origin of natural gas samples 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock, including the following steps: Based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radioactive origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the equilibrium compensation coefficient of the study area; According to the radioactive origin of natural gas in the target gas reservoir 40 The Ar abundance value, the average potassium content of the known source rock series in the target gas reservoir, and the equilibrium compensation coefficient of the study area are used to estimate the age of the source rock of the natural gas in the target gas reservoir; The estimated age of the source rock of the natural gas in the target gas reservoir is compared with the actual stratigraphic age of the source rock in the study area to determine the main source rock of the natural gas in the target gas reservoir.

9. The natural gas source comparison method according to claim 8, characterized in that: Based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radioactive origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the balance compensation coefficient of the study area, as follows: In the formula, C 40 Ar* 平均 Indicates the radioactive origin of natural gas in known gas reservoirs 40 The average value of Ar abundance, [K] represents the average potassium content of known source rock series in known gas reservoirs, represents the average porosity of known gas reservoirs, M represents the balance compensation coefficient of the study area, and X K Indicates that in nature 40 K abundance, λ K express 40 K decays into 40 The decay constant of Ar, λ represents 40 K decays into 40 Ar and 40 The total decay constant of Ca, t represents the age of known source rocks in known gas reservoirs in the study area.

10. A natural gas source comparison system, characterized in that: include: Sampling container, used to obtain natural gas samples from target gas reservoirs in the deep-ultra-deep high-evolution strata study area; A quadrupole mass spectrometer is used to determine the abundance of Ar components in air standards and natural gas samples; Noble Gas Isotope Mass Spectrometer for determination of noble gas isotope mass in air standards and natural gas samples 40 Ar / 36 Ar isotope measurements; The first calculation module is used to determine the Ar component abundance correction value in the natural gas sample by using the Ar component abundance correction coefficient of the air standard sample and the Ar component abundance measurement value in the natural gas sample; The second calculation module is used to calculate the 40 Ar / 36 The actual value of Ar isotopes and the corrected value of Ar component abundance are used to determine the radioactive origin of natural gas samples. 40 Ar abundance value; The third calculation module is used to calculate the radiogenic origin of the natural gas sample. 40 The Ar abundance value and known geological data of the target gas reservoir are used to determine the age of the source rock of the natural gas in the target gas reservoir and the main source rock.

11. The natural gas source comparison system according to claim 10, characterized in that: The known geological data of the target gas reservoir include the average porosity of the target gas reservoir, the average potassium content of the possible source rock series of the target gas reservoir, the average potassium content of the known source rock series in the known gas reservoirs in the study area, and the actual stratigraphic age of the known source rocks in the known gas reservoirs.

12. The natural gas source comparison system according to claim 11, characterized in that: The third calculation module is specifically used for: Based on the average porosity of known gas reservoirs in the same study area as the target gas reservoir, the average potassium content of known source rock series in the known gas reservoirs, and the radioactive origin of multiple natural gas samples in the known gas reservoirs, 40 The average value of Ar abundance is used to determine the equilibrium compensation coefficient of the study area; According to the radioactive origin of natural gas in the target gas reservoir 40 The Ar abundance value, the average potassium content of the known source rock series in the target gas reservoir, and the balance compensation coefficient of the study area are used to estimate the age of the source rock of the natural gas in the target gas reservoir; The estimated age of the source rock of the natural gas in the target gas reservoir is compared with the actual stratigraphic age of the source rock in the study area to determine the main source rock of the natural gas in the target gas reservoir.

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