Device and method for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions

Abstract

The present invention belongs to the technical field of hydrogen isotope determination, and specifically discloses an online extraction device and method for isotope composition of gaseous hydrocarbons in gas and mineral inclusions. The device comprises a first six-way valve, a water trap connected thereto, a ten-way valve, a water sample collection tube connected thereto, a carbon dioxide trap, a high-temperature reaction tube, a water trap, a second six-way valve, a quartz tube connected thereto, and a stable isotope mass spectrometer, and the ten-way valve is respectively connected to the first six-way valve and the second six-way valve; the method is as follows: mineral inclusion loading, mineral inclusion heating and degassing, gaseous hydrocarbon oxidation and gas collection in the mineral inclusions, H2O vaporization sampling and isotope testing, CO2 sublimation sampling and isotope testing, standard isotope testing, gaseous hydrocarbon oxidation in gas, gas collection testing. The present invention solves the technical problem of simultaneously testing carbon and hydrogen isotope compositions of gaseous hydrocarbons from a few ppm to 100% and enrichment testing of gas and mineral inclusions on a set of devices.

Description

Technical Field

[0001] The invention belongs to the technical field of isotope composition determination of gas and mineral inclusions, and specifically relates to an online continuous flow analysis and extraction device and method for carbon and hydrogen isotope compositions of gaseous hydrocarbons in gas and mineral inclusions. Background Art

[0002] Coalbed methane, oil and gas reservoirs, hot spring gas, soil, air and fluid inclusions may contain single or mixed gaseous hydrocarbons. Testing the carbon and hydrogen isotope compositions of these gaseous hydrocarbons can explore the properties of the source rocks and thermal maturity of coalbed methane, study the genesis and accumulation pattern of natural gas, determine the source and characteristics of gas, the greenhouse effect, and discuss the properties of ore-forming fluids, the sources of fluids and the temporal and spatial characteristics of oil and gas migration / accumulation.

[0003] Existing methods for testing the carbon and hydrogen isotope composition of gaseous hydrocarbons include vacuum ball milling, crushing, traditional explosion, improved sealed quartz tube explosion, and gas chromatography-mass spectrometry. Since the content of gaseous hydrocarbons in gas or fluid inclusions ranges from a few ppm to nearly 100%, the above-mentioned testing methods can only test the carbon or hydrogen isotope composition of gaseous hydrocarbons alone, or can only test low-concentration or high-concentration gaseous hydrocarbons. In addition, there are few standards for gaseous hydrocarbons and they are not easy to preserve, and the problem of standard sampling has not been well solved, resulting in the testing of the carbon and hydrogen isotope composition of gaseous hydrocarbons. There are disadvantages such as high sample preparation cost, low efficiency, and difficulty in determining the value. At present, there is no experimental technology that can be used for simultaneous testing and analysis of the carbon and hydrogen isotope composition of gaseous hydrocarbons in gas and mineral inclusions. Summary of the invention

[0004] The purpose of the present invention is to provide an online extraction device and method for the isotopic composition of gaseous hydrocarbons in gas and mineral inclusions, which solves the technical problem of simultaneously testing the carbon and hydrogen isotopic compositions of gaseous hydrocarbons ranging from a few ppm to 100% and enriching and testing gas and mineral inclusions on a set of devices, thereby improving the accuracy and efficiency of analysis and testing.

[0005] A technical solution to achieve the purpose of the present invention: an online extraction device for gaseous hydrocarbon isotopes in gas and mineral inclusions, the device comprising a first six-way valve, a multi-way water trap connected to the first six-way valve, a ten-way valve, a water sample collection tube connected to the ten-way valve, a carbon dioxide trap connected to the ten-way valve, a high-temperature reaction tube connected to the ten-way valve, a multi-way water trap connected to the ten-way valve, a second six-way valve, a quartz tube connected to the second six-way valve, and a stable isotope mass spectrometer connected to the second six-way valve, the ten-way valve being connected to the first six-way valve and the second six-way valve, respectively.

[0006] The sixth port T of the first six-way valve is connected to the quartz reaction tube, the first water trap, and the first helium gas inlet in sequence.

[0007] The first port O and the fourth port R of the first six-way valve are connected to the three-way connector, the fourth water trap, and the third helium inlet in sequence.

[0008] The second port P of the first six-way valve is connected to the gas collecting pipe, the fifth water trap, and the fourth helium gas inlet in sequence.

[0009] The two ends of the gas collecting pipe are respectively provided with a first valve and a second valve. The first valve is located between the gas collecting pipe and the fifth water trap, and the second valve is located between the gas collecting pipe and the second port P.

[0010] A first metal valve is provided between the first valve and the fifth water trap, and a second metal valve is provided between the first valve and the second port P.

[0011] A second water trap, a carbon dioxide trap, an injection column head, and a copper oxide reaction tube are sequentially arranged between the first port O of the first six-way valve and the first port A of the ten-way valve.

[0012] The quartz reaction tube is installed in the first temperature-controlled heating furnace, and the copper oxide reaction tube is installed in the second temperature-controlled heating furnace.

[0013] The ninth port I of the ten-way valve is connected to the third water trap and the second helium inlet in sequence.

[0014] The fifth port E of the ten-way valve is connected to the sixth water trap and the fifth helium inlet in sequence.

[0015] The eighth port H and the sixth port Z of the ten-way valve are respectively connected to the two ends of the high-temperature reaction tube.

[0016] The seventh port G and the tenth port J of the ten-way valve are respectively connected to the two ends of the water sample collection tube.

[0017] The third port C and the sixth port F of the ten-way valve are respectively connected to the two ends of the carbon dioxide collection pipe.

[0018] The second port B of the ten-way valve is communicated with the fourth port X of the second six-way valve.

[0019] The first port U of the second six-way valve is connected to the gas conversion interface and the stable isotope mass spectrometer in sequence.

[0020] The pipeline of the fifth port Y of the second six-way valve is placed in the first single-opening quartz tube, and the pipeline of the third port W of the second six-way valve is placed in the second single-opening quartz tube.

[0021] The ten-way valve is placed in the first temperature-controlled heating box, and the second six-way valve is placed in the second temperature-controlled heating box.

[0022] An online extraction method for gaseous hydrocarbon isotopes in gas and mineral inclusions using the above-mentioned online extraction device for gaseous hydrocarbon isotopes in gas and mineral inclusions, the method specifically comprising the following steps:

[0023] Step 1, mineral inclusion sampling;

[0024] Step 2, heating and adsorption of mineral inclusions to remove gases;

[0025] Step 3, oxidation of gaseous hydrocarbons in mineral inclusions and gas collection;

[0026] Step 4, H2O vaporization sampling and hydrogen isotope testing;

[0027] Step 5, CO2 sublimation sampling and carbon isotope testing;

[0028] Step 6: Standard water sample, methane, hydrogen, carbon, and carbon dioxide isotope testing;

[0029] Step 7: oxidizing gaseous hydrocarbons in the gas, collecting the gas, and testing the gas.

[0030] The specific steps of step 1 are as follows:

[0031] Step 1.1: Introduce high-purity helium into the helium inlet and adjust the first six-way valve to the mineral inclusion sample purge mode.

[0032] In step 1.1, when the mineral inclusion sample is purged in the mode, the helium flow directions of the ports of the first six-way valve are as follows: the second port P takes in gas and then outgases from the first port O; the third port Q and the fourth port R have the same gas to form a closed loop; the sixth port T takes in gas and then outgases from the fifth port S;

[0033] Step 1.2: Place the mineral inclusions into a quartz reaction tube and place the quartz reaction tube into the first temperature-controlled heating furnace.

[0034] In step 1.2, the first metal valve and the second metal valve are closed, and the first valve of the gas collection tube and the first valve of the gas collection tube are opened. At this time, the fourth helium gas inlet is used as the carrier gas of the copper oxide reaction tube, the mineral inclusions are loaded into the quartz reaction tube, and the quartz reaction tube is placed in the first temperature-controlled heating furnace.

[0035] The specific steps of step 2 are as follows: the first temperature-controlled heating furnace is set to a certain temperature, and the helium from the first helium inlet 1 enters the quartz reaction tube after being dried by the first water trap; the water adsorbed on the surface of the mineral sample and the low-temperature secondary inclusions are taken out by the helium and discharged into the air through the first six-way valve.

[0036] The specific steps of step 3 are as follows:

[0037] Step 3.1, adjusting the first six-way valve, the ten-way valve, and the second six-way valve to the gaseous hydrocarbon oxidation and gas collection modes of the mineral inclusion sample;

[0038] Step 3.2, placing the water sample collection tube in the first cold trap, and putting the carbon dioxide collection tube in the second cold trap 28 to collect gaseous hydrocarbon isotopes in the mineral inclusions.

[0039] In the step 3.2, the gas-liquid inclusion enters the first six-way valve and then releases gas, H2O is removed by the second water trap, and CO2 is adsorbed by the carbon dioxide trap; other gases enter the copper oxide reaction tube through the injection column head and are oxidized into CO2 and H2O and then enter the water sample collection tube, H2O is frozen and collected by alcohol dry ice in the first cold trap, and CO2 and other gases enter the carbon dioxide collection tube and are frozen and collected.

[0040] The specific steps of step 4 are as follows:

[0041] Step 4.1, adjust the ten-way valve and the second six-way valve to the H2O vaporization injection mode;

[0042] Step 4.2, heat the water sample collection tube, and after the solid water is vaporized and carried into the high-temperature reaction tube by helium, the gas generated by the reaction enters the stable isotope mass spectrometer to test the hydrogen isotope composition.

[0043] In the step 4.2, the first cold trap is removed, the electric heating device is turned on, the solid water in the water sample collection tube is rapidly vaporized, and is carried into the high-temperature reaction tube by helium, reacting with glassy carbon to generate H2 and CO. H2 and CO enter the second six-way valve and the gas conversion interface device and enter the stable isotope mass spectrometer to test the hydrogen isotope composition.

[0044] The specific steps of step 5 are as follows:

[0045] Step 5.1, adjust the ten-way valve and the second six-way valve to the CO2 sublimation injection mode;

[0046] Step 5.2, the helium gas passes through the sixth water trap and the carbon dioxide trap, and the CO2 in the carbon dioxide trap is rapidly released through the second six-way valve and the gas conversion interface device to enter the stable isotope mass spectrometer to test the carbon isotope composition.

[0047] In step 6, a water sample, methane and carbon dioxide are respectively injected into the injection column head using an injection needle, and then a standard water sample hydrogen isotope test, a standard methane hydrogen and carbon isotope test and a standard carbon dioxide isotope test are respectively performed.

[0048] In step 6, the standard water sample is vaporized and then passed through a copper oxide reaction tube and a ten-way valve and is frozen and collected by a water sample collection tube for hydrogen isotope testing; standard methane is driven by helium and enters the copper oxide reaction tube and is oxidized by copper oxide to generate CO2 and H2O. After being heated, CO2 and H2O pass through the ten-way valve in a gaseous state and are frozen and collected by a water sample collection tube for hydrogen isotope and carbon isotope composition testing.

[0049] In step 6, the standard CO2 gas passes through the injection column, the copper oxide reaction tube, and the water sample collection tube, and is then frozen and enriched by the carbon dioxide trap to perform a carbon isotope composition test.

[0050] The specific steps of step 7 are as follows:

[0051] Step 7.1, adjusting the first six-way valve to the purge mode of the gas collection pipe;

[0052] Step 7.2, adjusting the first six-way valve to the injection mode of the gas collection tube;

[0053] Step 7.3: Perform gas collection and isotope testing.

[0054] The beneficial technical effects of the present invention are:

[0055] (1) The present invention uses high-purity helium as a carrier gas, and connects a gas collection tube, a mineral inclusion explosion device, a standard injection column head, a gaseous hydrocarbon oxidation collection and injection device, and a stable isotope mass spectrometer to form an online continuous flow system, thereby realizing simultaneous testing of carbon and hydrogen isotope compositions in gaseous hydrocarbons of different contents.

[0056] (2) The gas collection tube of the present invention has a valve at each end, and can be evacuated before loading the sample. After reaching the sampling point, one of the valves can be opened to facilitate sampling. It is mainly used to collect low-content gaseous hydrocarbons for gas analysis, including air samples, soil gas, geothermal gas, etc.

[0057] (3) The mineral inclusion explosion device of the present invention is used for extracting fluid inclusions from various mineral samples. The temperature-controlled heating furnace can control the temperature, so that different explosion temperatures can be set according to research needs. A sample can also be heated in stages to extract fluid inclusions from different mineralization periods. Under the protection of high-purity helium, the fluid inclusions are released and instantly taken away from the high-temperature zone by the airflow, thereby reducing the occurrence of isotope exchange between the released gases.

[0058] (4) The standard injection column head of the present invention can be injected with liquid water for hydrogen isotope analysis, CO2 gas for carbon isotope analysis, and methane gas for carbon and hydrogen isotope analysis. It can also be injected with gas samples with high gaseous hydrocarbon content. By using multiple standard injection tests, a multi-standard calibration curve can be established, which solves the problem of difficulty in accurately determining isotopes due to the small number of gaseous hydrocarbon standards.

[0059] (5) The present invention adopts the technology of combining a ten-way valve with a six-way valve, which can realize the conversion of the gas collection tube sampling mode and the mineral inclusion explosion sampling mode. The gaseous hydrocarbons purified by the carbon dioxide trap and the water trap are oxidized with copper oxide to generate H2O and CO2. The pipeline is heated to above 150°C, and the H2O remains in the gaseous state and enters the -80°C water sample collection tube to be captured, and the CO2 gas is collected by the -196°C carbon dioxide collection tube. Through the switching function of the ten-way valve and the six-way valve, H2O can be tested first, and H2O enters the high-temperature furnace to react with glassy carbon to generate H2 and CO. The hydrogen isotope composition is tested after separation by the chromatographic column, and the CO2 bypasses the high-temperature furnace and is directly sampled to test the carbon isotope composition.

[0060] (6) The present invention adopts a detachable quick connector to facilitate the installation and disassembly of the gas collection tube and the quartz reaction tube in the fluid inclusion device. The connection between the ten-way valve, the six-way valve and the 1 / 16-inch stainless steel pipe is sealed with a polytetrafluoroethylene gasket, and the other pipes are sealed with metal gaskets. The entire online continuous flow system is well sealed and is not affected by air. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 This is a schematic structural diagram of a device for extracting gaseous hydrocarbons from gas and mineral inclusions provided by the present invention.

[0062] In the figure:

[0063] 1 is the first helium gas inlet, 2 is the first water trap, 3 is the quartz reaction tube, and 4 is the first temperature-controlled heating furnace;

[0064] 5 is the first six-way valve, O is the first port of the first six-way valve, P is the second port of the first six-way valve, Q is the third port of the first six-way valve, R is the fourth port of the first six-way valve, S is the fifth port of the first six-way valve, and T is the sixth port of the first six-way valve;

[0065] 6 is a second water trap, 7 is a carbon dioxide trap, 8 is a sample injection column head, 9 is a copper oxide reaction tube, 10 is a second temperature-controlled heating furnace, 11 is a second helium inlet, 12 is a third water trap, 13 is a third helium inlet, 14 is a fourth water trap, 15 is a three-way connector, 16 is a fourth helium inlet, 17 is a fifth water trap, and 18 is a first metal valve;

[0066] 19 is a gas collecting pipe, 19-1 is a first valve of the gas collecting pipe, and 19-2 is a second valve of the gas collecting pipe;

[0067] 20 is a second metal valve, 21 is a high temperature reaction tube, 22 is an electric heating device, 23 is a water sample collection tube, 24 is a first cold trap, and 25 is a first temperature control heating box;

[0068] 26 is a ten-way valve, A is the first port of the ten-way valve, B is the second port of the ten-way valve, C is the third port of the ten-way valve, D is the fourth port of the ten-way valve, E is the fifth port of the ten-way valve, F is the sixth port of the ten-way valve, G is the seventh port of the ten-way valve, H is the eighth port of the ten-way valve, I is the ninth port of the ten-way valve, and J is the tenth port of the ten-way valve;

[0069] 27 is a carbon dioxide trap, 28 is a second cold trap, 29 is a sixth water trap, 30 is a fifth helium gas inlet, and 31 is a first single-opening quartz tube;

[0070] 32 is a second six-way valve, U is a first port of the second six-way valve, V is a second port of the second six-way valve, W is a third port of the second six-way valve, X is a fourth port of the second six-way valve, Y is a fifth port of the second six-way valve, and Z is a sixth port of the second six-way valve;

[0071] 33 is a second temperature-controlled heating box, 34 is a gas conversion interface device, and 35 is a stable isotope mass spectrometer. DETAILED DESCRIPTION

[0072] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0073] like Figure 1 As shown, an online extraction device for gaseous hydrocarbon isotopes in gas and mineral inclusions of this embodiment comprises a first helium inlet 1, a second helium inlet 11, a third helium inlet 13, a fourth helium inlet 16, a fifth helium inlet 30, a first water trap 2, a second water trap 6, a third water trap 12, a fourth water trap 14, a fifth water trap 17, a sixth water trap 29, a quartz reaction tube 3, a first temperature-controlled heating furnace 4, a second temperature-controlled heating furnace 10, a first six-way valve 5, a second six-way valve 32, a carbon dioxide trap 7, an injection column head 8, an oxygen Copper oxide reaction tube 9, three-way joint 15, first metal valve 18, second metal valve 20, gas collection tube 19, first valve 19-1 of gas collection tube, second valve 19-2 of gas collection tube, high temperature reaction tube 21, electric heating device 22, water sample collection tube 23, first cold trap 24, second cold trap 28, first temperature-controlled heating box 25, second temperature-controlled heating box 33, ten-way valve 26, carbon dioxide trap 27, first single-opening quartz tube 31, second single-opening quartz tube 36, gas conversion interface 34 and stable isotope mass spectrometer 35.

[0074] like Figure 1 As shown, the first helium gas inlet 1 is connected to the sixth port T of the first six-way valve 5 through the first water trap 2 and the quartz reaction tube 3 in sequence; the first helium gas inlet 1 is connected to the inlet of the first water trap 2 through a pipeline, the outlet of the first water trap 2 is connected to the inlet of the quartz reaction tube 3 through a pipeline, and the outlet of the quartz reaction tube 3 is connected to the sixth port T of the first six-way valve 5 through a pipeline.

[0075] After the helium comes out from the first port O of the first six-way valve 5 through the sixth port T of the first six-way valve 5, it passes through the second water trap 6, the carbon dioxide trap 7, the injection column head 8, and the copper oxide reaction tube 9 to reach the first port A of the ten-way valve 26; the inlet of the second water trap 6 is connected with the first port O of the first six-way valve 5 through a pipeline, the outlet of the second water trap 6 is connected with the inlet of the carbon dioxide trap 7 through a pipeline, the outlet of the carbon dioxide trap 7 is connected with the inlet of the injection column head 8 through a pipeline, the outlet of the injection column head 8 is connected with the inlet of the copper oxide reaction tube 9 through a pipeline, and the outlet of the copper oxide reaction tube 9 is connected with the first port A of the ten-way valve 26 through a pipeline.

[0076] The second helium inlet 11 is connected to the ninth port I of the ten-way valve 26 via the third water trap 12; the second helium inlet 11 is connected to the inlet of the third water trap 12 through a pipeline, and the outlet of the third water trap 12 is connected to the ninth port I of the ten-way valve through a pipeline.

[0077] The third helium gas inlet 13 is connected to the third port Q and the fourth port R of the first six-way valve 5 through the fourth water well 14 and the three-way joint 15; the third helium gas inlet 13 is connected to the inlet of the fourth water well 14 through a pipeline, the outlet of the fourth water well 14 is connected to the first joint of the three-way joint 15 through a pipeline, and the other two joints of the three-way joint 15 are respectively connected to the third port Q of the first six-way valve 5 and the fourth port R of the first six-way valve 5 through pipelines.

[0078] The fourth helium gas inlet 16 is connected to the second port P of the first six-way valve 5 through the fifth water trap 17 and the gas collecting pipe 19; the outlet of the fourth helium gas inlet 16 is connected to the inlet of the fifth water trap 17 through a pipeline; the outlet of the fifth water trap 17 is connected to the first valve 19-1 of the gas collecting pipe 19 through a pipeline, and a first metal valve 18 is provided on the pipeline between the fifth water trap 17 and the first valve 19-1 of the gas collecting pipe; the second valve 19-2 of the gas collecting pipe 19 is connected to the second port P of the first six-way valve 5 through a pipeline, and a second metal valve 20 is provided on the pipeline between the second valve 19-2 of the gas collecting pipe 1 and the second port P of the first six-way valve.

[0079] The fifth helium inlet 30 is connected to the fifth port E of the ten-way valve 26 via the sixth water trap 29; the fifth helium inlet 30 is connected to the inlet of the sixth water trap 29 through a pipeline, and the outlet of the sixth water trap 29 is connected to the fifth port E of the ten-way valve 26 through a pipeline.

[0080] Both ends of the high temperature reaction tube 21 are connected to the eighth port H of the ten-way valve 26 and the sixth port Z of the second six-way valve 32 through pipelines, respectively.

[0081] The two ends of the water sample collection tube 23 are respectively connected to the seventh port G of the ten-way valve 26 and the tenth port J of the ten-way valve 26 through pipelines. The two ends of the water sample collection tube 23 are respectively connected to the two ends of the electric heating device 22 through cables.

[0082] Both ends of the carbon dioxide collection pipe 27 are connected to the third port C of the ten-way valve 26 and the sixth port F of the ten-way valve 26 through pipelines, respectively.

[0083] The second port B of the ten-way valve 26 is connected to the fourth port X of the second six-way valve 32 through a pipeline. The stable isotope mass spectrometer 35 is connected to the first port U of the second six-way valve 32 through a gas conversion interface 34, and the outlet of the gas conversion interface 34 is connected to the first port U of the second six-way valve 32 through a pipeline.

[0084] Among them, the quartz reaction tube 3 is nested in the groove of the first temperature-controlled heating furnace 4, the copper oxide reaction tube 9 is nested in the groove of the second temperature-controlled heating furnace 10, the water sample collection tube 23 is placed in the first cold trap 24, and the carbon dioxide trap 27 is placed in the second cold trap 28; the outlet pipeline is placed at the bottom of the first single-opening quartz tube 31 and the second single-opening quartz tube 36, the pipeline connected to the fifth port Y of the second six-way valve 32 is placed in the first single-opening quartz tube 31, and the pipeline connected to the third port W of the second six-way valve 32 is placed in the second single-opening quartz tube 36. The ten-way valve 26 is placed in the first temperature-controlled heating box 25, and the second six-way valve 32 is placed in the second temperature-controlled heating box 33.

[0085] In this embodiment, the connecting pipelines between the components are all made of stainless steel pipes with an outer diameter of 1 / 16 inch.

[0086] In this embodiment, the first metal valve 18 and the second metal valve 20 are both made of stainless steel.

[0087] In this embodiment, the quartz reaction tube 3 is a 1 / 4 inch quartz glass tube, and both ends are connected by quick connectors for easy disassembly and sample loading.

[0088] In this embodiment, the first water trap 2, the third water trap 12, the fourth water trap 14, the fifth water trap 17 and the sixth water trap 29 can effectively adsorb moisture in the helium gas, and the second water trap 6 and the carbon dioxide trap 7 are used to adsorb H2O and CO2 in the fluid inclusions and the gas to purify the gaseous hydrocarbons.

[0089] In this embodiment, the temperature of the first temperature-controlled heating box 4 can be set to different temperatures according to different minerals. Quartz can be set to 600°C, and calcite can be set to 420°C. Fluid inclusions at different temperature stages can also be extracted according to research needs, thereby achieving the purpose of staged heating.

[0090] In this embodiment, the second temperature-controlled heating box 10 is set at 800° C. to heat the copper oxide in the copper oxide reaction tube 9, providing an oxidant to the gaseous hydrocarbons to oxidize them into CO2 and H2O, which is convenient for gas enrichment and testing of carbon and hydrogen isotope compositions.

[0091] In this embodiment, when the first metal valve 18 and the second metal valve 20 are opened and the two valves of the gas collection pipe 19, the first valve 19-1 of the gas collection pipe and the second valve 19-2 of the gas collection pipe are closed, the third helium gas inlet 13 and the fourth helium gas inlet 16 are mainly used to purge the air at both ends of the gas collection pipe 19 to reduce interference with the gas in the gas collection pipe.

[0092] In this embodiment, the injection column head 8 is mainly used for the injection of water sample standard substances. The hydrogen isotope standard can be injected into the sealing gasket of the injection column head 8 by sucking 0.2 μL of water sample using a liquid injection needle. The water is vaporized in the 150°C pipeline and enriched by the water sample collection tube 23. The solid water in the water sample collection tube 23 is heated by the electric heating device 22, and the temperature is raised from -80°C to above 200°C in about 5 seconds. After the water is vaporized, it is brought into the 1380°C high-temperature reaction tube 21 by helium, and reacts with the glassy carbon therein to generate H2 and CO. After separation by the chromatographic column, they enter the stable isotope mass spectrometer to test the hydrogen isotope composition. By testing the hydrogen isotope composition of different water sample standards, a multi-standard calibration curve can be established for the precise determination of hydrogen isotopes of gaseous hydrocarbons in gas and mineral inclusions.

[0093] In this embodiment, the injection column head 8 can also be used for the injection of gas standard methane or carbon dioxide. Methane reacts with copper oxide in a copper oxide reactor 9 at 800°C to generate CO2 and H2O. Carbon dioxide passes through the copper oxide reactor, and CO2 is collected by a carbon dioxide trap. After CO2 is released, it is sent to a stable isotope mass spectrometer to test the carbon isotope composition. By testing the carbon isotope composition of multiple gas standard CO2, a carbon isotope multi-standard calibration curve can be established for the precise determination of carbon isotopes of gaseous hydrocarbons in gas and mineral inclusions.

[0094] like Figure 1 As shown, a method for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions, the method specifically comprises the following steps:

[0095] Step 1: Mineral inclusion sampling

[0096] Step 1.1: Introduce high-purity helium into the helium inlet, and adjust the first six-way valve 5 to the mineral inclusion sample purge mode.

[0097] 99.999% high purity helium is introduced into the first helium inlet 1, the second helium inlet 11, the third helium inlet 13, the fourth helium inlet 16 and the fifth helium inlet 30. The first six-way valve 5 is adjusted to the mineral inclusion sample purge mode. In the mineral inclusion sample purge mode, the helium flow directions of each port of the first six-way valve 5 are as follows: the second port P takes in gas and then discharges gas from the first port O; the third port Q and the fourth port R have the same gas to form a closed loop; the sixth port T takes in gas and then discharges gas from the fifth port S.

[0098] Step 1.2: Place the mineral inclusions into the quartz reaction tube 3, and place the quartz reaction tube 3 into the first temperature-controlled heating furnace 4.

[0099] The first metal valve 18 and the second metal valve 20 are closed, and the two valves of the gas collecting tube 19, the first valve 19-1 of the gas collecting tube and the first valve 19-2 of the gas collecting tube, are opened. At this time, the fourth helium gas inlet 16 is used as the carrier gas for the copper oxide reaction tube 9; the mineral inclusions are loaded into the quartz reaction tube 3, the upper cover of the first temperature-controlled heating furnace 4 is opened, and the quartz reaction tube 3 is placed in the first temperature-controlled heating furnace 4 through the quick connector.

[0100] Step 2: Heating and degassing mineral inclusions

[0101] The temperature of the first temperature-controlled heating furnace 4 is set to 200° C. The helium from the first helium inlet 1 is dried by the first water trap 2 and then enters the quartz reaction tube 3. The gas adsorbed on the surface of the mineral sample, especially water and low-temperature secondary inclusions, is brought out by the helium and enters the sixth port T of the first six-way valve 5, and is discharged into the air from the fifth port S of the first six-way valve 5 for 10 minutes to reduce the interference of other gases on the native gaseous hydrocarbon inclusions.

[0102] Step 3: Oxidation of gaseous hydrocarbons in mineral inclusions and gas collection

[0103] Step 3.1, adjust the first six-way valve 5, the ten-way valve 26, and the second six-way valve 32 to the gaseous hydrocarbon oxidation and gas collection mode of the mineral inclusion sample

[0104] After degassing is completed, the first six-way valve 5 is adjusted to the gaseous hydrocarbon oxidation and gas collection mode of the mineral inclusion sample. In this mode, the helium flow directions of the various ports of the first six-way valve 5 are as follows: the second port P and the third port Q are in a connected state; the fourth port R takes in air and then exhausts air from the fifth port S; the sixth port T takes in air and then exhausts air from the first port O.

[0105] The ten-way valve 26 is adjusted to the gaseous hydrocarbon oxidation and gas collection mode of the mineral inclusion sample. In this mode, the helium flow directions of the various ports of the ten-way valve 26 are as follows: the first port A takes in air and then exhausts it from the tenth port J, the third port C takes in air and then exhausts it from the second port B; the fifth port E takes in air and then exhausts it from the fourth port D; the seventh port G takes in air and then exhausts it from the sixth port F; the ninth port I takes in air and then exhausts it from the eighth port H.

[0106] The second six-way valve 32 is adjusted to the gaseous hydrocarbon oxidation and gas collection mode of the mineral inclusion sample. In this mode, the helium flow directions of the various ports of the second six-way valve 32 are as follows: the second port V takes in air and then exhausts it from the third port W; the fourth port X takes in air and then exhausts it from the fifth port Y; the sixth port Z takes in air and then exhausts it from the first port U.

[0107] Step 3.2: Place the water sample collection tube 23 in the first cold trap 24, and put the carbon dioxide collection tube 27 in the second cold trap 28 to collect the gaseous hydrocarbon isotopes in the mineral inclusions.

[0108] The water sample collection tube 23 is placed in the first cold trap 24, and alcohol dry ice is added to the first cold trap 24; the carbon dioxide collection tube 27 is put on the second cold trap 28, and liquid nitrogen is poured into the second cold trap 28; the carbon dioxide collection tube 27 is filled with nickel wire to prevent the generation of carbon dioxide crystals, which is conducive to the complete collection and rapid release of carbon dioxide gas.

[0109] Due to the protection of high-purity helium with a flow rate of 90 mL / min, the mineral inclusions in the quartz reaction tube 3 burst and release gas-liquid inclusions, which are quickly taken away from the high-temperature zone by helium, thereby reducing the occurrence of isotope exchange between the inclusion components. The gas-liquid inclusions enter the sixth port T of the first six-way valve 5, and gas is discharged from the first port O. H2O is removed by the second water trap 6, and CO2 is adsorbed by the carbon dioxide trap 7. Other gases enter the copper oxide reaction tube 9 through the injection column head 8 and are oxidized into CO2 and H2O, and enter the first port A of the ten-way valve 26, and gas is discharged from the tenth port J and enter the water sample collection tube 23. H2O is frozen and collected by alcohol dry ice at -80°C in the first cold trap 24, CO2 and other gases enter the seventh port G of the ten-way valve 26, come out from the sixth port F and enter the carbon dioxide collection pipe 27 at -196°C to be frozen and collected, other gases enter the third port C of the ten-way valve 26, come out from the second port B and enter the fourth port X of the second six-way valve 32, come out from the fifth port Y and enter the first open quartz tube 31 and are discharged into the air, which lasts for 10 minutes.

[0110] Step 4: H2O vaporization injection and hydrogen isotope testing

[0111] Step 4.1: Adjust the ten-way valve 26 and the second six-way valve 32 to the H2O vaporization injection mode.

[0112] The ten-way valve 26 is adjusted to the H2O vaporization injection mode. In the H2O vaporization injection mode, the helium flow directions of the various ports of the ten-way valve 26 are as follows: the first port A takes in air and then discharges it from the second port B, the third port C takes in air and then discharges it from the fourth port D; the fifth port E takes in air and then discharges it from the sixth port F; the seventh port G takes in air and then discharges it from the eighth port H; the ninth port I takes in air and then discharges it from the tenth port J.

[0113] The second six-way valve 32 is adjusted to the H2O vaporization injection mode. In the H2O vaporization injection mode, the helium flow directions of the ports of the second six-way valve 32 are as follows: the second port V takes in air and then discharges air from the third port W; the fourth port X takes in air and then discharges air from the fifth port Y; the sixth port Z takes in air and then discharges air from the first port U.

[0114] Step 4.2, heating the water sample collection tube 23, solid water is vaporized and brought into the high temperature reaction tube 21 by helium, and the gas generated by the reaction enters the stable isotope mass spectrometer 35 to test the hydrogen isotope composition.

[0115] Remove the first cold trap 24, turn on the switch of the electric heating device 22, and the solid water in the water sample collection tube 23 is rapidly vaporized and carried by helium into a 1 / 16-inch stainless steel pipe at 150°C. After reaching the seventh port G of the ten-way valve 26, it comes out from the eighth port H and enters the 1380°C high-temperature reaction tube 21, reacts with the glassy carbon therein to generate H2 and CO. Then, H2 and CO enter the sixth port Z of the second six-way valve 32, and after coming out from the first port U, they pass through the gas conversion interface device 34 and enter the stable isotope mass spectrometer 35 to test the hydrogen isotope composition.

[0116] Step 5: CO2 sublimation sampling and carbon isotope testing

[0117] Step 5.1: Adjust the ten-way valve 26 and the second six-way valve 32 to the CO2 sublimation injection mode.

[0118] Adjust the ten-way valve 26 to the CO2 sublimation injection mode. When in the CO2 sublimation injection mode, the helium flow directions of the various ports of the ten-way valve 26 are as follows: the first port A takes in air and then outgases from the second port B, the third port C takes in air and then outgases from the fourth port D; the fifth port E takes in air and then outgases from the sixth port F; the seventh port G takes in air and then outgases from the eighth port H; the ninth port I takes in air and then outgases from the tenth port J.

[0119] The second six-way valve 32 is adjusted to the CO2 sublimation injection mode. In the CO2 sublimation injection mode, the helium flow directions of the ports of the second six-way valve 32 are as follows: the first port U takes in air and then discharges air from the second port V; the fourth port X takes in air and then discharges air from the third port W; the sixth port Z takes in air and then discharges air from the fifth port Y.

[0120] Step 5.2, helium passes through the sixth water trap 29 and the carbon dioxide trap 27, CO2 in the carbon dioxide trap 27 is rapidly released through the second six-way valve 32 and the gas conversion interface device 34, and enters the stable isotope mass spectrometer 35 to test the carbon isotope composition

[0121] The helium from the fifth helium inlet 30 is dried by the sixth water trap 29 and then enters the fifth port E of the ten-way valve 26, and then comes out from the sixth port F and enters the carbon dioxide trap 27. The second cold trap 28 is removed, and the CO2 in the carbon dioxide trap 27 is rapidly released and brought into the third port C of the ten-way valve 26, and then comes out from the fourth port D and enters the second port V of the second six-way valve 32, and then enters the stable isotope mass spectrometer 35 from the first port U through the gas conversion interface device 34 to test the carbon isotope composition.

[0122] Step 6: Standard water sample, methane, hydrogen, carbon, and carbon dioxide isotope testing

[0123] Through the sealing pad of the injection column head 8, a water sample can be injected into the injection column head 8 using a liquid injection needle, or methane or carbon dioxide can be injected into the injection column head 8 using a gas injection needle.

[0124] Step 6.1: Hydrogen isotope test of standard water sample

[0125] Standard water sample: Use a liquid injection needle to suck in 0.2μL of standard water sample and inject it into the injection column head 8. The temperature in the pipeline is above 150℃, so that the water in the injection column head 8 is vaporized. After vaporization, the water enters the first port A of the ten-way valve 26 through the copper oxide reaction tube 9, and then comes out from the tenth port J of the ten-way valve 26 and is frozen and collected by the water sample collection tube 23. The hydrogen isotope test is the same as step 4.

[0126] Step 6.2: Standard methane hydrogen and carbon isotope test

[0127] Standard methane: 5 mL of methane gas is inhaled through a gas injection needle and injected into the system through the injection column head 8. Driven by helium, the methane gas enters the copper oxide reaction tube 9 and is oxidized by the copper oxide to generate CO2 and H2O. The pipeline is heated to above 150°C by a heating belt. CO2 and H2O enter the first port A of the ten-way valve 26 in gaseous state, and are frozen and collected by the water sample collection tube 23 after coming out from the tenth port J. CO2 enters the seventh port G of the ten-way valve 26 again, and is frozen and enriched by the carbon dioxide trap 27 after coming out from the sixth port F. The hydrogen isotope composition test is the same as step 4, and the carbon isotope composition test is the same as step 5.

[0128] Step 6.3: Standard carbon dioxide isotope test

[0129] Standard carbon dioxide: Use a gas injection needle to inhale 5 mL of standard CO2 gas and inject it into the system through the injection column head 8. CO2 enters the first port A of the ten-way valve 26 through the copper oxide reaction tube 9, and then passes through the water sample collection tube 23 after coming out from the tenth port J and enters the seventh port G of the ten-way valve 26 again. After coming out from the sixth port F, it is frozen and enriched by the carbon dioxide trap 27. The CO2 sublimation injection and carbon isotope composition test are the same as step 5.

[0130] Step 7: Oxidation of gaseous hydrocarbons in the gas, gas collection, and testing

[0131] Step 7.1: Adjust the first six-way valve 5 to the purge mode of the gas collection pipe 19

[0132] Gas containing gaseous hydrocarbons is generally stored in a gas collection pipe 19 with two valves. After being connected to the system, the first six-way valve 5 is adjusted to the purge mode of the gas collection pipe 19. When the gas collection pipe 19 is in the purge mode, the helium flow of each port of the first six-way valve 5 is as follows: the third port Q takes in air and then outgases from the second port P; the fourth port R takes in air and then outgases from the fifth port S; the sixth port T takes in air and then outgases from the first port O. Gas collection pipe 19

[0133] The first valve 19-1 and the second valve 19-2 of the gas collection pipe 19 are closed, the first metal valve 18 and the second metal valve 20 are opened, and the helium at the fourth helium inlet 16 is dried by the fifth water trap 17 and then discharged into the air from the first metal valve 18, in order to purge the air at the first valve 19-1 of the gas collection pipe 19. The helium at the third helium inlet 13 is absorbed by the fourth water trap 14 and then enters the third port Q of the first six-way valve 5 through the three-way joint 15, and then comes out from the second port P of the first six-way valve 5 and is discharged into the air from the second metal valve 20, in order to purge the air at the second valve 19-2 of the gas collection pipe 19. The purge time lasts for 10 minutes.

[0134] Step 7.2: Adjust the first six-way valve 5 to the injection mode of the gas collection tube 19

[0135] The first six-way valve 5 is adjusted to the injection mode of the gas collection tube 19. When in the injection mode of the gas collection tube 19, the helium flow directions of the various ports of the first six-way valve 5 are as follows: the second port P takes in air and then exhausts air from the first port O; the third port Q and the fourth port R have the same gas to form a closed loop; the sixth port T takes in air and then exhausts air from the fifth port S.

[0136] Step 7.3: Gas collection and isotope testing

[0137] While adjusting the first six-way valve 5 to the injection mode of the gas collection tube 19, open the first valve 19-1 and the second valve 19-2 of the gas collection tube 19. Driven by the high-purity helium, the gas in the gas collection tube 19 enters the second port P of the first six-way valve 5. The oxidation, gas collection and isotope testing after coming out of the first port O are the same as steps 3, 4 and 5.

[0138] The present invention is described in detail above with reference to the accompanying drawings and embodiments, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of ordinary technicians in the field without departing from the purpose of the present invention. The contents not described in detail in the present invention can adopt the existing technology.

Claims

1. An online extraction device for gaseous hydrocarbon isotopes in gas and mineral inclusions, characterized in that: The device comprises a first six-way valve (5), a multi-way water trap connected to the first six-way valve (5), a ten-way valve (26), a water sample collection tube (23) connected to the ten-way valve (26), a carbon dioxide collection tube (27) connected to the ten-way valve (26), a high-temperature reaction tube (21) connected to the ten-way valve (26), a multi-way water trap connected to the ten-way valve (26), a second six-way valve (32), a quartz tube connected to the second six-way valve (32), a stable isotope mass spectrometer (35) connected to the second six-way valve (32), and the ten-way valve (26). ) are respectively connected to the first six-way valve (5) and the second six-way valve (32); the sixth port T of the first six-way valve (5) is connected to the quartz reaction tube (3), the first water trap (2), and the first helium inlet (1) in sequence; the first port O and the fourth port R of the first six-way valve (5) are connected to the three-way connector (15), the fourth water trap (14), and the third helium inlet (13) in sequence; the second port P of the first six-way valve (5) is connected to the gas collection pipe (19), the fifth water trap (17), the fourth helium inlet (16) in sequence ), a second water trap (6), a carbon dioxide trap (7), an injection column head (8), and a copper oxide reaction tube (9) are sequentially arranged between the first port O of the first six-way valve (5) and the first port A of the ten-way valve (26); the ninth port I of the ten-way valve (26) is sequentially connected to the third water trap (12) and the second helium inlet (11); the fifth port E of the ten-way valve (26) is sequentially connected to the sixth water trap (29) and the fifth helium inlet (30); the eighth port H and the sixth port Z of the ten-way valve (26) are sequentially connected to the third water trap (12) and the second helium inlet (11); The ten-way valve (26) is connected to the two ends of the high-temperature reaction tube (21); the seventh port G and the tenth port J of the ten-way valve (26) are connected to the two ends of the water sample collection tube (23); the third port C and the sixth port F of the ten-way valve (26) are connected to the two ends of the carbon dioxide collection tube (27); the second port B of the ten-way valve (26) is connected to the fourth port X of the second six-way valve (32); the first port U of the second six-way valve (32) is connected to the gas conversion interface device (34) and the stable isotope mass spectrometer (35) in sequence.

2. The device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 1, characterized in that: A first valve (19-1) and a second valve (19-2) are respectively provided at both ends of the gas collection pipe (19); the first valve (19-1) is located between the gas collection pipe (19) and the fifth water trap (17); and the second valve (19-2) is located between the gas collection pipe (19) and the second port P.

3. The device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 2, characterized in that: A first metal valve (18) is provided between the first valve (19-1) and the fifth water trap (17), and a second metal valve (20) is provided between the second valve (19-2) and the second port P.

4. The device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 3, characterized in that: The quartz reaction tube (3) is installed in a first temperature-controlled heating furnace (4), and the copper oxide reaction tube (9) is installed in a second temperature-controlled heating furnace (10).

5. The device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 4, characterized in that: The pipeline of the fifth port Y of the second six-way valve (32) is placed in the first single-opening quartz tube (31), and the pipeline of the third port W of the second six-way valve (32) is placed in the second single-opening quartz tube (36).

6. The device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 5, characterized in that: The ten-way valve (26) is placed in the first temperature-controlled heating box (25), and the second six-way valve (32) is placed in the second temperature-controlled heating box (33).

7. A method for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions using the device for online extraction of gaseous hydrocarbon isotopes in gas and mineral inclusions as claimed in any one of claims 1 to 6, characterized in that: The method specifically comprises the following steps: Step 1: Mineral inclusion sampling; the specific steps of step 1 are as follows: Step 1.1: Introduce high-purity helium into the helium inlet and adjust the first six-way valve (5) to the mineral inclusion sample purge mode. In step 1.1, when the mineral inclusion sample is purged in the mode, the helium flow directions of the ports of the first six-way valve (5) are as follows: the second port P takes in gas and then outgases from the first port O; the third port Q and the fourth port R have the same gas to form a closed loop; the sixth port T takes in gas and then outgases from the fifth port S; Step 1.2: Load the mineral inclusion into the quartz reaction tube (3), and place the quartz reaction tube (3) into the first temperature-controlled heating furnace (4). In step 1.2, the first metal valve (18) and the second metal valve (20) are closed, and the first valve (19-1) and the second valve (19-2) of the gas collection tube (19) are opened. At this time, the fourth helium gas inlet (16) is used as a carrier gas for the copper oxide reaction tube (9), and the mineral inclusions are loaded into the quartz reaction tube (3), and the quartz reaction tube (3) is placed in the first temperature-controlled heating furnace (4); Step 2, heating and degassing the mineral inclusions; the specific steps of step 2 are as follows: setting the first temperature-controlled heating furnace (4) to a certain temperature, the helium from the first helium inlet (1) is dried by the first water trap (2) and then enters the quartz reaction tube (3); the water adsorbed on the surface of the mineral sample and the low-temperature secondary inclusions are taken out by the helium and discharged into the air through the first six-way valve (5); Step 3, oxidation of gaseous hydrocarbons in mineral inclusions and gas collection; the specific steps of step 3 are as follows: Step 3.1, adjusting the first six-way valve (5), the ten-way valve (26), and the second six-way valve (32) to a gaseous hydrocarbon oxidation and gas collection mode for the mineral inclusion sample; Step 3.2, placing the water sample collection tube (23) in the first cold trap (24), and putting the carbon dioxide collection tube (27) in the second cold trap (28), to collect gaseous hydrocarbon isotopes in the mineral inclusions; In the step 3.2, the gas-liquid inclusion enters the first six-way valve (5) and then releases gas, H2O is removed by the second water trap (6), and CO2 is adsorbed by the carbon dioxide trap (7); other gases enter the copper oxide reaction tube (9) through the injection column head (8) and are oxidized into CO2 and H2O, and then enter the water sample collection tube (23), H2O is frozen and collected by alcohol dry ice in the first cold trap (24), and CO2 and other gases enter the carbon dioxide collection tube (27) and are frozen and collected; Step 4, H2O vaporization sampling and hydrogen isotope testing; the specific steps of step 4 are as follows: Step 4.1, adjusting the ten-way valve (26) and the second six-way valve (32) to the H2O vaporization injection mode; Step 4.2, heating the water sample collection tube (23), after the solid water is vaporized and carried into the high temperature reaction tube (21) by helium, the gas generated by the reaction enters the stable isotope mass spectrometer (35) to test the hydrogen isotope composition; Step 5, CO2 sublimation sampling and carbon isotope testing; the specific steps of step 5 are as follows: Step 5.1, adjusting the ten-way valve (26) and the second six-way valve (32) to the CO2 sublimation injection mode; Step 5.2, the helium gas passes through the sixth water trap (29) and the carbon dioxide collection tube (27), and the CO2 in the carbon dioxide collection tube (27) is quickly released through the second six-way valve (32) and the gas conversion interface device (34), and enters the stable isotope mass spectrometer (35) to test the carbon isotope composition; Step 6, standard water sample, methane hydrogen carbon, and carbon dioxide isotope testing; in said step 6, a water sample, methane, and carbon dioxide are respectively injected into the injection column head (8) using an injection needle, and then a standard water sample hydrogen isotope test, a standard methane hydrogen carbon isotope test, and a standard carbon dioxide isotope test are respectively performed; Step 7, oxidation of gaseous hydrocarbons in the gas, gas collection, and testing; the specific steps of step 7 are as follows: Step 7.1, adjusting the first six-way valve (5) to a purge mode of the gas collection pipe (19); Step 7.2, adjusting the first six-way valve (5) to the injection mode of the gas collection tube (19); Step 7.3: Perform gas collection and isotope testing.

8. An online method for extracting gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 7, characterized in that: In step 4.2, the first cold trap (24) is removed, the switch of the electric heating device (22) is turned on, and the solid water in the water sample collection tube (23) is rapidly vaporized and carried into the high-temperature reaction tube (21) by the helium gas, and reacts with the glassy carbon to generate H2 and CO. The H2 and CO enter the second six-way valve (32) and the gas conversion interface device (34) and enter the stable isotope mass spectrometer (35) to test the hydrogen isotope composition.

9. An online method for extracting gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 8, characterized in that: In step 6, the standard water sample is vaporized and then passed through the copper oxide reaction tube (9) and the ten-way valve (26) and then frozen and collected by the water sample collection tube (23) for hydrogen isotope testing; standard methane is driven by helium and enters the copper oxide reaction tube (9) and is oxidized by copper oxide to generate CO2 and H2O. After being heated, the CO2 and H2O pass through the ten-way valve (26) in a gaseous state and are then frozen and collected by the water sample collection tube (23) for hydrogen isotope and carbon isotope composition testing.

10. An online method for extracting gaseous hydrocarbon isotopes in gas and mineral inclusions according to claim 9, characterized in that: In step 6, the standard CO2 gas passes through the injection column head (8), the copper oxide reaction tube (9), and the water sample collection tube (23), and is then frozen and enriched by the carbon dioxide collection tube (27) to perform a carbon isotope composition test.

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