Isotope measurement device and method for geological carbon-containing fluid

Abstract

The invention discloses an isotope measurement device and method for a geological carbon-containing fluid, and relates to the technical field of geology basic physical property measurement, the isotope measurement device comprises a reactor, a temperature control system, a pressure control system and a microscopic Raman test system, the reactor comprises a capillary tube used for containing the geological carbon-containing fluid and a heat conduction silver cover wrapping the geological carbon-containing fluid, the heat conduction silver cover is located in the capillary tube so that the geological carbon-containing fluid can form a fluid wrapping body, and the capillary tube is suitable for packaging the fluid wrapping body; the temperature control system is used for simulating the real temperature of the geological carbon-containing fluid reservoir; the pressure control system is used for simulating a real pressure environment of a geological carbon-containing fluid reservoir; the microscopic Raman testing system is used for identifying and analyzing spectral characteristics of various substances in the geological carbon-containing fluid, and further measuring the isotope content of different component systems in the geological carbon-containing fluid. The invention also provides an isotope measurement method to obtain the microscopic Raman spectrum characteristics of different geological carbon-containing fluids at different temperatures and pressures.

Description

Technical Field

[0001] The present invention relates to the technical field of basic physical property measurement in geology, and more specifically to an isotope measurement device and method for geological carbon-containing fluid. Background Art

[0002] The methane-carbon dioxide-water carbon-containing fluid system is the main fluid form for the migration and cross-sphere circulation of carbon-containing volatiles in the ocean-crust environment. The high-precision quantitative analysis of the source, distribution, migration, convergence and evolution of the carbon dioxide-methane-water fluid system in different geological stages and environments is the data and analysis basis and key work for the study of the spatiotemporal evolution of carbon-containing fluids and carbon cycle in this system.

[0003] At present, relevant units have established a variety of sampling and analysis technologies for the methane-carbon dioxide-water system to address the above-mentioned problems. For example, infrared absorption spectroscopy technology and laser Raman quantitative analysis methods are used in combination with gas-liquid separation equipment and high-pressure chamber devices to achieve in-situ analysis of carbon dioxide-methane concentrations; in-situ sensor devices equipped with mass spectrometers are used to conduct real-time in-situ analysis of methane-carbon dioxide concentrations and their isotopes in seawater and continental shelf sediments; and a closed gas chamber method is used in combination with a quantitative analysis method of gas components and isotopes to achieve real-time observation and source analysis of carbon dioxide eruptions in volcanic areas.

[0004] The above carbonaceous fluid sampling and analysis method only conducts quantitative analysis on the carbonaceous fluids enriched in the area at the current moment. It is unable to make an accurate division of the carbonaceous fluids in different evolutionary periods and has the disadvantage of low calculation accuracy on the properties of various carbonaceous fluid systems. This limits the study on the activity, migration and evolution laws of multi-period carbonaceous geological fluids in complex marine geological environments.

[0005] Therefore, in order to reveal the fluid sources and activity patterns of multi-period carbonaceous geological fluids, break through the limitations of high-precision calculations of inclusions in various carbonaceous fluid systems, and clarify the activity patterns of various carbonaceous fluids in different geological periods under complex marine environments, it is urgent to design a high-precision identification and quantitative calculation device and analysis method that can observe carbon dioxide isotopes from different sources and evolution processes in real time. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide an isotope measurement device and method for geological carbon-containing fluids, so as to solve the defects in the prior art that it is impossible to accurately divide the carbon-containing geological fluids of each period in different evolutionary periods and the low calculation accuracy of the properties of multiple carbon-containing fluid systems, which limits the study of the activity, migration and evolution laws of multi-period carbon-containing geological fluids in complex marine geological environments.

[0007] To achieve the above objectives, the first objective of the present invention is to provide an isotope measuring device for geological carbon-containing fluids, which is used for determining the composition-density-isotope of geological carbon-containing fluids. The isotope measuring device comprises:

[0008] A reactor, comprising a capillary tube for containing the geological carbonaceous fluid and a heat-conducting silver cover for encapsulating the geological carbonaceous fluid, wherein the heat-conducting silver cover is located in the capillary tube so that the geological carbonaceous fluid forms a fluid inclusion, and the capillary tube is suitable for encapsulating the fluid inclusion;

[0009] A temperature control system, used to simulate the actual temperature of a geological carbonaceous fluid reservoir and provide a set temperature range for the generation of the geological carbonaceous fluid;

[0010] A pressure control system, used to simulate the real pressure environment of the geological carbonaceous fluid reservoir and provide a set pressure range for the generation of the geological carbonaceous fluid;

[0011] The micro-Raman testing system is used to identify and analyze the spectral characteristics of various substances in the geological carbon-containing fluid, and then determine the isotope content of different component systems in the geological carbon-containing fluid.

[0012] Preferably, the temperature control system comprises a hot and cold stage, a liquid nitrogen control subsystem and a thermocouple. The temperature control range of the hot and cold stage is -190-500°C. The thermocouple is used to control the heating part of the hot and cold stage, and the liquid nitrogen control subsystem is used to control the cooling part of the hot and cold stage.

[0013] Preferably, the pressure control system includes a valve, a pressure sensor and a pressure pump, and the valve includes a first valve and a second valve connected to each other, the first inlet of the first valve is connected to the tip of the capillary, the first outlet of the first valve is connected to the second inlet of the second valve, the second outlet of the second valve is connected to the pressure pump, and the pressure sensor is also installed on the second valve.

[0014] Preferably, the booster pump is a manual or electric structure, and the pressure transmission medium of the booster pump is pure water; the valve is a #60-15HF2 model manufactured by HIP, and the upper pressure limit of the valve is 206MPa; the pressure sensor is a DP41-S-230 model manufactured by Omega.

[0015] Preferably, the micro-Raman testing system comprises:

[0016] A laser light source for generating at least one laser beam;

[0017] A spectrometer, used to identify and analyze the spectral characteristics of various substances in the fluid inclusions;

[0018] A three-dimensional mobile platform, used for placing the reactor and suitable for adjusting the position of the capillary;

[0019] A microscope is arranged above one side of the three-dimensional moving platform to observe the sample in the capillary.

[0020] Preferably, the laser light source is a diode-pumped solid-state laser; and the spectrometer is a LabRAM HR800 laser Raman spectrometer.

[0021] The second object of the present invention is to provide an isotope measurement method for geological carbon-containing fluids, using the isotope measurement device for geological carbon-containing fluids described above, the isotope measurement method comprises the steps of:

[0022] Step S 100 : Carbon dioxide gas for preparing isotope standards;

[0023] Step S 200 : A capillary high pressure chamber for preparing pure carbon dioxide gas on one of the capillaries;

[0024] Step S 300 : Prepare a capillary high pressure chamber for gas-liquid two-phase carbon dioxide fluid on another capillary:

[0025] Step S 400 : The geological carbon-containing fluid samples in the capillary high-pressure cavity of the pure carbon dioxide gas and the capillary high-pressure cavity of the gas-liquid two-phase carbon dioxide fluid are tested and analyzed by micro-Raman spectroscopy.

[0026] Preferably, in step S 100 The method for preparing isotope standard carbon dioxide gas comprises:

[0027] Step S 110 :Vacuum inside the capillary;

[0028] Add phosphoric acid, carbonate reactant and desiccant into the capillary tube, open the valve and operate the vacuum pump to extract the internal air in the capillary tube;

[0029] Step S 120 : Preparation of carbon dioxide;

[0030] Close the valve and vacuum pump, and keep the vacuum inside the capillary. Open the phosphoric acid dropper bottle and gradually drip phosphoric acid into the carbonate powder to react chemically and generate a large amount of carbon dioxide gas.

[0031] Step S 130 : Drying the liquid water mixed in the carbon dioxide gas;

[0032] The carbon dioxide generated by phosphoric acid and carbonate powder is allowed to enter the desiccant along the pipeline in the capillary tube to remove liquid water mixed in from the phosphoric acid solution and the reaction process;

[0033] Step S 140 : Vacuum to remove impurities;

[0034] The dried and dehydrated carbon dioxide gas then enters a freezing tank filled with liquid nitrogen, and the valve and vacuum pump are opened to evacuate the gas. The carbon dioxide is frozen into a solid phase and remains in the capillary pipeline, and the mixed impurity gas is pumped out by the vacuum pump until all the generated carbon dioxide gas is frozen and purified into the pipeline of the liquid nitrogen tank, and then the valve and vacuum pump are closed;

[0035] Step S 150 : Carbon dioxide purification;

[0036] The liquid nitrogen freezing tank is removed, and the solid carbon dioxide frozen in the capillary pipeline is slowly heated up and restored to the gas phase, thereby entering the gas collecting device and being purified by removing water and impurities.

[0037] Preferably, in step S 200 Among them, the method for preparing a capillary high-pressure chamber for pure carbon dioxide gas comprises:

[0038] Step S 210 :Preparation of capillary tube;

[0039] A capillary tube with a length of 20-30 cm is selected, and both ends of the capillary tube are sealed with oxyhydrogen flame welding, and one end of the capillary tube is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube is adapted to the high-pressure valve;

[0040] Step S 220 : Remove the film on the outer wall of the capillary;

[0041] After the capillary tube is firmly fixed, the film on the outer wall of the observation end of the capillary tube is removed to make it completely transparent;

[0042] Step S 230 : Capillary gas conduction;

[0043] Cut off the closed end outside the sleeve, insert the capillary tube with a gas-conducting capillary tube, and introduce the entire pure carbon dioxide gas into the capillary tube;

[0044] Step S 240 : Mercury seal the capillary;

[0045] Pull out the gas-conducting capillary, insert an injection capillary connected to a mercury syringe into the capillary, and inject a 1-2 cm column of mercury to seal the target gas;

[0046] Step S250 : Capillary fixation;

[0047] The prepared capillary is connected and fixed to the valve, and high-pressure water is used as the pressure transmission medium to push the mercury column to move and compress the pure carbon dioxide gas inside to achieve sensitive pressure regulation.

[0048] Preferably, in step S 300 Among them, the method for preparing a capillary high-pressure chamber for a gas-liquid two-phase carbon dioxide fluid comprises:

[0049] Step S 310 :Preparation of capillary tube;

[0050] A capillary tube with a length of 20-30 cm is selected, and both ends of the capillary tube are sealed with oxyhydrogen flame welding, and one end of the capillary tube is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube is adapted to the high-pressure valve;

[0051] Step S 320 : Remove the film on the outer wall of the capillary;

[0052] After the capillary tube is firmly fixed, the film on the outer wall of the observation end of the capillary tube is removed to make it completely transparent;

[0053] Step S 330 : Capillary gas conduction;

[0054] Cut off the closed end of the outer side of the sleeve, insert the gas-conducting capillary into the capillary, and introduce the entire pure carbon dioxide gas into the capillary;

[0055] Step S 340 :Capillary conduction:

[0056] After the gas-conducting capillary is withdrawn, the liquid-conducting capillary connected to the target solution syringe is quickly inserted. When the front end of the liquid-conducting capillary reaches the predetermined position of the experiment, the solution is injected to seal the front gas, the liquid-conducting capillary is withdrawn, and the liquid-injection capillary connected to the mercury syringe is inserted into the interior of the capillary until the gas-liquid two-phase carbon dioxide fluid is introduced;

[0057] Step S 350 : Mercury seal the capillary;

[0058] The injection capillary is drawn out, and an injection capillary connected to a mercury syringe is inserted into the capillary, and a 1-2 cm column of mercury is injected to seal the internal gas-liquid two-phase carbon dioxide fluid, thereby forming a gas-liquid two-phase carbon dioxide capillary sample;

[0059] Step S 360 : Calculation of gas-liquid molar ratio:

[0060] The gas-liquid two-phase carbon dioxide capillary sample is set up on a hot and cold stage, and the tip of the gas-liquid two-phase carbon dioxide capillary sample is placed under a microscope to observe and determine the length ratio of the gas-liquid two-phase column at the corresponding temperature and pressure, and accurately calculate the molar ratio of gas and solution based on the gas state equation and the molar volume of the substance.

[0061] Compared with the prior art, the present invention has the following advantages and effects:

[0062] The isotope measuring device of geological carbon-containing fluid in the present application is used to carry out the component-density-isotope determination of geological carbon-containing fluid under a wide range of temperature and pressure. The isotope measuring device includes a reactor, a temperature control system, a pressure control system and a micro-Raman testing system, wherein the reactor includes a capillary for containing the geological carbon-containing fluid and a heat-conducting silver cover for wrapping the geological carbon-containing fluid, the heat-conducting silver cover is located in the capillary so that the geological carbon-containing fluid is formed into a fluid inclusion, and the capillary is suitable for encapsulating the fluid inclusion; the temperature control system is used to simulate the actual temperature of the geological carbon-containing fluid reservoir and provide a set temperature range for the generation of geological carbon-containing fluid; the pressure control system is used to simulate the actual pressure environment of the geological carbon-containing fluid reservoir and provide a set pressure range for the generation of the geological carbon-containing fluid; the micro-Raman testing system is used to identify and analyze the spectral characteristics of various substances in the geological carbon-containing fluid, and then determine the isotope content of different component systems in the geological carbon-containing fluid, and real-time determine the Raman spectrum of carbon dioxide fluid under a wide range of temperature and pressure conditions. The isotope measuring device can prepare multiple systems of carbon-containing geological fluids according to the characteristics of geological carbon-containing fluid components, and simultaneously measure the geological carbon-containing fluid components, density, isotopes and their change characteristics under multiple carbon-containing fluid combinations;

[0063] 2. This isotope measurement method for geological carbon-containing fluids can be used to carry out a series of component-density-isotope determination experiments of geological carbon-containing fluids under a wide range of temperatures and pressures, thereby establishing a series of component-density-isotope high-precision quantitative calculation models under a wide range of temperatures and pressures, and comprehensively explore the activity and evolution laws of carbon-containing geological fluids in different geological environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 This is a schematic diagram of the structure of an isotope measurement device for geological carbon-containing fluids according to an embodiment of the present invention;

[0065] Figure 2 It is a schematic diagram of the process of isotope measurement of geological carbon-containing fluid in an embodiment of the present invention;

[0066] Figure 3 This is a schematic diagram of the isotope measurement method in an embodiment of the present invention;

[0067] Figure 4This is a schematic flow chart of a method for preparing isotope standard carbon dioxide gas in an embodiment of the present invention;

[0068] Figure 5 This is a schematic flow chart of a method for preparing pure carbon dioxide gas in a capillary high pressure chamber according to an embodiment of the present invention;

[0069] Figure 6 Schematic diagram of the process of preparing a capillary high-pressure chamber for a gas-liquid two-phase carbon dioxide fluid in an embodiment of the present invention.

[0070] Description of reference numerals:

[0071] 1- Micro Raman testing system;

[0072] 11-laser light source; 12-microscope; 13-three-dimensional moving platform;

[0073] 2-reactor;

[0074] 21-capillary; 22-thermal conductive silver cover;

[0075] 3-Temperature control system;

[0076] 31-hot and cold stage; 32-thermocouple;

[0077] 4-Pressure control system;

[0078] 41-valve; 411-first valve; 412-second valve; 42-pressure sensor; 421-pressure display; 43-boosting pump; 44-connecting pipe;

[0079] 5-controller; 51-data connection line; 511-first data connection line; 512-second data connection line. DETAILED DESCRIPTION

[0080] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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.

[0081] In the description of the present invention, it should be noted that the terms "include" and "comprises" used herein should be understood as inclusive and open-ended, rather than exclusive. Specifically, when the terms "include" and "comprises" and their synonyms are used in the specification and claims, they mean including the specified features, steps or components. These terms cannot be understood to exclude the existence of other features, steps or components.

[0082] Carbon is constantly moving between the biosphere, atmosphere, lithosphere, crust-mantle, ocean-continent and other geological spheres. The carbon-containing fluids between the spheres are interconnected through various processes and different forms to form a carbon cycle. The occurrence forms of carbon-containing fluids in various stages of the carbon cycle and the laws of their transport and aggregation in time and space have become hot issues in current scientific research and industry.

[0083] Various carbon-containing fluids widely distributed in the shallow crust (e.g., water-methane fluids ejected from cold springs and mud volcanoes in the seafloor and near-seafloor areas; large amounts of methane and ethane distributed in hydrate reservoirs; alkane compounds formed by high temperature and high pressure after organic matter is buried in sedimentary basins, and methane-CO2 fluids formed by oxidation) originate from CO2-rich fluids that are channeled to the shallow part of the mantle by volcanic diapirs and various levels of faults;

[0084] In order to accurately reflect the sources and evolution of multi-period carbonaceous fluids in multiple geological periods and geological environments, please refer to Figure 1-6 As shown, in one embodiment of the present invention, an isotope measuring device for geological carbon-containing fluid is provided, which is used to carry out component-density-isotope determination of geological carbon-containing fluid under a wide range of temperature and pressure. The isotope measuring device includes a reactor 2, a temperature control system 3, a pressure control system 4 and a micro-Raman testing system 1, wherein:

[0085] The reactor 2 comprises a capillary 21 for containing geological carbonaceous fluid and a heat-conducting silver cover 22 for encapsulating the geological carbonaceous fluid. The heat-conducting silver cover 22 is located in the capillary 21 so that the geological carbonaceous fluid forms a fluid inclusion. The capillary 21 is suitable for encapsulating the fluid inclusion.

[0086] The temperature control system 3 is used to simulate the actual temperature of the geological carbonaceous fluid reservoir and provide a set temperature range for the generation of geological carbonaceous fluid;

[0087] The pressure control system 4 is used to simulate the real pressure environment of the geological carbonaceous fluid reservoir and provide a set pressure range for the generation of the geological carbonaceous fluid;

[0088] The micro-Raman testing system 1 is used to identify and analyze the spectral characteristics of various substances in the geological carbon-containing fluid, and then determine the isotope content of different component systems in the geological carbon-containing fluid.

[0089] Specifically in this embodiment, the core part of the device is a reactor 2, which includes a capillary 21 and a heat-conducting silver cover 22, wherein the capillary 21 is used to contain geological carbon-containing fluids, and the heat-conducting silver cover 22 wraps these fluids to form fluid inclusions, which is convenient for more sensitive perception of temperature changes, so as to adjust the position of the geological carbon-containing fluids so that they are evenly heated, and allow the fluids to be packaged and tested under controlled conditions, ensuring the accuracy and repeatability of the experiment. The temperature control system 3 is used to simulate the actual temperature of the geological carbon-containing fluid reservoir and provide a set temperature range for the generation of geological carbon-containing fluids. The pressure control system 4 is used to simulate the actual pressure environment of the geological carbon-containing fluid reservoir and provide a set pressure range for the generation of geological carbon-containing fluids. The micro-Raman test system 1 is a key analytical tool of the device, which is used to identify and analyze the spectral characteristics of various substances in the geological carbon-containing fluids. By analyzing these spectral characteristics, the isotopic content of different component systems in the geological carbon-containing fluids can be determined.

[0090] Therefore, by precisely controlling temperature and pressure, the device can simulate the conditions of geological carbon-containing fluids in the natural environment, thereby providing more accurate isotope measurement results; the device is also suitable for geological carbon-containing fluids under a wide range of temperatures and pressures, and it can be applied to fluid analysis in a variety of geological environments and conditions, increasing its breadth and flexibility of application; by simulating the actual temperature and pressure environment of the geological carbon-containing fluid reservoir, the device can provide experimental conditions that are closer to the natural environment; the micro-Raman testing system 1 can provide high-sensitivity and high-resolution spectral analysis, which is crucial for identifying and measuring trace components and isotopes in geological carbon-containing fluids, and helps to deeply understand the chemical composition and evolution process of the fluid.

[0091] It needs to be further explained here that the capillary 21 in this embodiment is used to contain geological carbon-containing fluid. The capillary 21 is made of quartz glass and can withstand high temperature and high pressure. The interior of the capillary 21 has a high temperature resistant, high pressure, transparent quartz cavity. The inner diameter of the quartz cavity is 100μm and the outer diameter is 794μm. The maximum temperature resistance can reach 500°C and the maximum pressure resistance can reach 220MPa. The whole is transparent, which is convenient for testing the spectrum of the sample by laser Raman spectrometer.

[0092] See also Figure 1 As shown, the temperature control system 3 includes a hot and cold stage 31, a liquid nitrogen control subsystem and a thermocouple 32. The hot and cold stage 31 is a CAP500 model manufactured by Linkam, and the temperature control range of the hot and cold stage 31 is -190-500°C. The thermocouple 32 is used to control the heating part of the hot and cold stage 31, and the liquid nitrogen control subsystem is used to control the cooling part of the hot and cold stage.

[0093] Specifically in this embodiment, the hot and cold stage 31 is a CAP500 model produced by Linkam, and the temperature control range of the hot and cold stage is -190°C to 500°C. This wide temperature range enables CAP500 to adapt to a variety of experimental conditions, especially experiments under extreme temperature conditions. The working principle of the hot and cold stage 31 is based on heat conduction and temperature control technology, and is usually composed of a temperature control system, a heating element, a cooling system and a test platform, wherein:

[0094] The liquid nitrogen control subsystem is used to control the cooling part of the hot and cold stage 31. The liquid nitrogen trace supply can control the liquid nitrogen flow rate from drop by drop to 1L / min, and there are multiple liquid nitrogen level control modes, including the use of temperature sensors and time control, the use of two temperature sensors for control (high and low liquid levels), etc., to provide precise temperature control for the hot and cold stage 31, especially in experiments requiring extremely low temperatures.

[0095] The thermocouple 32 is used as a heating element to control the temperature rise part of the hot and cold stage 31. The thermocouple 32 is a temperature sensor that can generate thermoelectric potential to measure temperature. Preferably, the thermocouple 32 in this embodiment is a K-type high-precision thermocouple. The type and material of the thermocouple 32 determine its acquisition range. For example, the K-type thermocouple is suitable for a temperature range of -200°C to 1200°C.

[0096] Thus, the temperature control system 3 can achieve precise control from extremely low temperature to high temperature through the cooperation of the hot and cold stage 31 and the liquid nitrogen control subsystem, which is crucial for geological carbon-containing fluid experiments that need to be conducted at a specific temperature, because even a slight change in temperature may affect the experimental results. In addition, by precisely controlling the temperature, the system can simulate various temperature conditions that geological carbon-containing fluids may encounter in nature, thereby providing experimental data that is closer to reality; the coordinated use of the liquid nitrogen control subsystem and the thermocouple 32 can quickly adjust the temperature of the hot and cold stage 31, shorten the experimental preparation time, and improve the experimental efficiency.

[0097] It should be noted that the temperature control accuracy of the temperature control system 3 in this embodiment is related to the temperature control range. For example, the temperature error in the range of 25-100°C is ±0.2°C, and the temperature error in the range of 100-300°C is ±0.5°C.

[0098] See also Figure 1 As shown, the pressure control system 4 includes a valve 41, a pressure sensor 42 and a pressure pump 43, and the valve 41 includes a first valve 411 and a second valve 412 which are connected to each other, the first inlet of the first valve 411 is connected to the tip of the capillary 21, the first outlet of the first valve 411 is connected to the second inlet of the second valve 412, the second outlet of the second valve 412 is connected to the pressure pump 43, and the second valve 412 is also equipped with a pressure sensor 42.

[0099] Specifically in this embodiment, the first valve 411 and the second valve 412 are used to precisely control the flow of the fluid. For example, the first valve 411 is responsible for connecting the fluid in the capillary 21 with other parts of the pressure control system 4, while the second valve 412 is responsible for guiding the fluid to the pressure pump 43 and monitoring the pressure through the pressure sensor 42. This configuration of the valves helps to precisely control the flow direction and pressure of the fluid and ensure safe and stable operation of the system.

[0100] The pressure sensor 42 is mounted on the second valve 412 and displays the pressure in the monitoring system in real time through the pressure display 421. It can be understood that the working principle of the pressure sensor 42 is to convert the measured pressure into a signal form that is easy to use, such as voltage, current, etc. These signals can be used for feedback control to ensure that the system pressure is maintained at a set value.

[0101] The booster pump 43 is used to increase the pressure in the system. The booster pump 43 can automatically adjust the pressure according to system requirements to keep the fluid flowing at an appropriate pressure in the capillary 21. This automatic adjustment capability helps to simulate the real pressure environment of a geological carbonaceous fluid reservoir.

[0102] See also Figure 1 As shown, the pressure pump 43 is a manual or electric structure, and the pressure transmission medium of the pressure pump 43 is pure water; the valve 41 is a #60-15HF2 model manufactured by HIP, and the upper pressure limit of the valve 41 is 206MPa; the pressure sensor 42 is a DP41-S-230 model manufactured by Omega.

[0103] As a preferred mode of this embodiment, the pressure control system 4 is realized by a manual pressure pump with pure water as the pressure transmission medium. The real-time pressure in the high-pressure system is realized by a DP41-S-230 pressure sensor 42 produced by Omega and a pressure display 421 of model PX91 N0-30KSV produced by Omega. The valve 41 used to connect the high-pressure pipeline in the high-temperature and high-pressure experiment is model #60-15HF2 produced by HIP, and the upper limit of the pressure is about 206MPa.

[0104] See also Figure 1 As shown, the micro Raman testing system 1 includes a laser light source 11, a microscope 12, a spectrometer and a three-dimensional moving platform 13, wherein:

[0105] The laser light source 11 is used to generate at least one laser beam; the spectrometer is used to identify and analyze the spectral characteristics of various substances in the fluid inclusions; the three-dimensional mobile platform 13 is used to place the reactor 2 and is suitable for adjusting the azimuth position of the capillary 21; the microscope 12 is arranged on one side of the three-dimensional mobile platform 13 to observe the sample in the capillary 21.

[0106] Specifically, the laser light source 11 is used to generate at least one laser beam, which irradiates the sample and causes inelastic scattering of the sample molecules, namely Raman scattering. The frequency difference between the scattered light and the incident light is called Raman shift, which is the key to determining the molecular structure of the substance. The microscope 12 is used to observe the sample in the capillary 21. It amplifies the image of the sample so that the tiny sample can be observed and analyzed in detail. The spectrometer is used to identify and analyze the spectral characteristics of various substances in the fluid inclusions. It determines the molecular structure of the substance by analyzing the frequency changes of Raman scattered light. The three-dimensional mobile platform 13 is a fully automatic motor-controlled movement with a minimum moving step of 0.1 μm. The three-dimensional mobile platform 13 is used to place the reactor 2 and is suitable for adjusting the azimuth position of the capillary 21. This platform can accurately control the position of the sample to ensure that the laser beam accurately irradiates the area of ​​interest, and can move in three dimensions to accommodate different sample shapes and sizes.

[0107] See also Figure 1 As shown, the laser light source 11 is a ventus532 diode-pumped solid-state laser manufactured by Laser Quantum; the spectrometer is a LabRAMHR800 laser Raman spectrometer manufactured by HORI BA Job in Yvon SAS.

[0108] As a preferred method of this embodiment, the laser light source 11 is a ventus 532 diode-pumped solid-state laser produced by LaserQuantum, which adopts high-power solid-state light-emitting (1064nm) crystal frequency doubling technology to produce an ideal single-frequency TEM00 mode 532nm laser and is equipped with a power control unit to control the laser frequency and beam pointing to maintain stability.

[0109] The laser Raman spectrometer is equipped with a resolution grating and an observation lens. The resolution grating is equipped with two models: 300 scale / mm and 1800 scale / mm for signal collection in different situations. The observation lens is an Ol ympus 50x telephoto lens with a numerical aperture of 0.5. A neon lamp is set up between the microscope and the sample to correct the Raman spectrum displacement of each substance.

[0110] In addition, the laser Raman spectrometer in the embodiment of the present invention is installed with spectral data acquisition software, which can remove the baseline of the collected spectral data, automatically mark the peak position, fit the spectral peak, and calculate the central frequency shift, half-height width, spectral intensity and integrated area of ​​the spectral peak to meet the needs of Raman spectral testing and processing.

[0111] See also Figure 3As shown, an embodiment of the present invention further provides an isotope measurement method for geological carbon-containing fluids, using the isotope measurement device for geological carbon-containing fluids described above, and the isotope measurement method comprises the steps of:

[0112] Step S 100 : Carbon dioxide gas for preparing isotope standards;

[0113] Step S 200 : A capillary high pressure chamber for preparing pure carbon dioxide gas on one of the capillaries 21;

[0114] Step S 300 : A capillary high pressure chamber for preparing a gas-liquid two-phase carbon dioxide fluid on another capillary 21:

[0115] Step S 400 :The geological carbon-containing fluid samples in the capillary high-pressure chamber of pure carbon dioxide gas and the capillary high-pressure chamber of gas-liquid two-phase carbon dioxide fluid were tested and analyzed by micro-Raman spectroscopy.

[0116] Specifically in this embodiment, a capillary 21 (with a high-temperature and high-pressure quartz cavity) is used with various carbon-containing fluid standards to prepare standard samples that can accurately and real-time reflect the changes in each component of carbon-containing geological fluids under a wide temperature and pressure environment. Microscopic laser Raman spectroscopy high-precision quantitative technology is used as an analysis method to accurately determine the isotopes of multiple component systems of carbon-containing geological fluids, and a series of component-density-isotope high-precision quantitative calculation quantitative models under a wide range of temperature and pressure are established to achieve high-precision component-density calculation and ancient temperature and pressure recovery of natural fluid inclusions in carbon-containing geological fluid systems under a wide range of temperature and pressure, and to clarify the activities and evolution laws of various carbon-containing fluids in different geological periods under complex marine geological environments.

[0117] Therefore, by building a complete process from sample preparation to final analysis, the accuracy and reliability of isotope measurement are ensured. 2 The gas provides a reference standard for the measurement, while the preparation of the high-pressure chamber simulates the high-pressure conditions in the geological environment. Micro-Raman spectroscopy test analysis provides a highly sensitive and specific analytical method that can accurately determine the isotopic composition of geological carbon-containing fluids. The effect of this method is that it can provide detailed information about the carbon cycle and fluid migration in geological processes, which is of great significance for understanding geological history and predicting geological resources.

[0118] See also Figure 4 As shown, specifically to step S of the present invention 100 The method for preparing isotope standard carbon dioxide gas comprises:

[0119] Step S 110: The interior of the capillary 21 is evacuated;

[0120] Phosphoric acid, carbonate reactant and desiccant are added into the capillary tube 21 , and the valve 41 is opened and the vacuum pump is operated to evacuate the internal air in the capillary tube 21 .

[0121] In this step, the air in the capillary 21 is extracted by opening the valve 41 and the vacuum pump to create a vacuum environment for the subsequent addition of reactants and the conduct of chemical reactions, while reducing the interference of oxygen and other gases on the reaction.

[0122] Step S 120 : Preparation of carbon dioxide;

[0123] Close the valve 41 and the vacuum pump, and keep the interior of the capillary 21 in a vacuum state. Open the phosphoric acid dropper bottle and gradually drip phosphoric acid into the carbonate powder to generate a chemical reaction to generate a large amount of carbon dioxide gas.

[0124] In this step, after closing the valve 41 and the vacuum pump, the interior of the capillary 21 is kept in a vacuum state, which helps to reduce the interference of other gases and ensure that the generated carbon dioxide gas will not be diluted by the external air. 3 PO 4 ) and carbonates (such as sodium carbonate Na 2 CO 3 ) reaction to generate carbon dioxide (CO 2 ), water (H 2 O) and the corresponding phosphates (such as sodium phosphate Na 3 PO4), the chemical equation of the reaction can be expressed as:

[0125] H 3 PO 4 +Na 2 CO 3 →Na 3 PO 4 +H 2 O+CO 2

[0126] By gradually adding phosphoric acid, the reaction rate can be controlled to avoid a rapid reaction that causes a sharp increase in pressure, while ensuring the uniformity and completeness of the reaction.

[0127] Step S 130 : Drying the liquid water mixed in the carbon dioxide gas;

[0128] The carbon dioxide generated by phosphoric acid and carbonate powder is allowed to enter the desiccant along the pipeline in the capillary 21 to remove liquid water mixed in from the phosphoric acid solution and the reaction process.

[0129] Desiccant can be divided into two categories: chemical desiccant and physical desiccant. In this step, physical desiccant is used, which can absorb moisture without chemical reaction. Common physical desiccant includes molecular sieve, silica gel, etc.

[0130] For example, molecular sieve is a porous solid material with a specific pore size and shape that can select and filter out molecules and impurities of a specific size. The pore size and pores of the molecular sieve can be regulated and changed to effectively remove moisture from carbon dioxide.

[0131] By utilizing the properties of supercritical fluid, in which carbon dioxide is transformed into a supercritical fluid at a certain temperature and pressure, and has the properties of high solubility, high diffusivity and high permeability, the moisture in the material can be quickly transferred to carbon dioxide to achieve the purpose of drying.

[0132] The reduced moisture content in the dried carbon dioxide gas can improve the efficiency and accuracy of subsequent steps such as purification and isotope analysis.

[0133] Step S 140 : Vacuum to remove impurities;

[0134] The dried and dehydrated carbon dioxide gas then enters a freezing tank filled with liquid nitrogen, and valve 41 and a vacuum pump are opened to evacuate the gas. The carbon dioxide is frozen into a solid phase and remains in the pipeline of the capillary 21, and the mixed impurity gas is extracted by the vacuum pump until all the generated carbon dioxide gas is frozen and purified into the pipeline of the liquid nitrogen tank, and then the valve 41 and the vacuum pump are closed.

[0135] In this step, the liquid nitrogen freezing tank keeps the liquid nitrogen in a low temperature state for a long time by maintaining the low temperature and high vacuum environment inside. This low temperature environment can be used to freeze carbon dioxide gas and turn it into a solid phase, which is convenient for subsequent purification and processing.

[0136] The vacuum pump generates suction through mechanical force (such as rotation or reciprocating motion) to extract the gas in the container or space to achieve the purpose of reducing the pressure. In this step, the vacuum pump is used to extract the impurity gas in the capillary 21, including unreacted raw material gas and other gases generated during the reaction process.

[0137] Carbon dioxide gas is frozen into a solid phase under the action of liquid nitrogen, while other impurity gases can be extracted under vacuum due to their different boiling points. The synergistic effect of freezing and vacuuming can effectively separate carbon dioxide and other gases.

[0138] Step S 150 : Carbon dioxide purification;

[0139] The liquid nitrogen freezing tank is removed, so that the solid carbon dioxide frozen in the pipeline of the capillary tube 21 is slowly heated up and restored to the gas phase, thereby entering the gas collecting device and being purified by removing water and impurities.

[0140] In this step, by removing the liquid nitrogen freezing tank, the solid carbon dioxide in the capillary 21 is slowly heated up, and the carbon dioxide is transformed from the solid phase to the gas phase by temperature change. This process is based on the phase change principle of matter, that is, matter can be transformed between solid, liquid and gas at different temperatures and pressures.

[0141] The carbon dioxide restored to the gas phase enters the gas collection device. During the gas collection process, moisture and impurity gases in the carbon dioxide are removed by further physical or chemical methods. Removal technologies include the use of desiccants, adsorbents or membrane separation technologies to ensure the high purity of the carbon dioxide.

[0142] See also Figure 5 As shown, specifically to step S of the present invention 200 Among them, the method for preparing a capillary high-pressure chamber for pure carbon dioxide gas comprises:

[0143] Step S 210 : Initially prepare capillary 21;

[0144] A capillary tube 21 with a length of 20-30 cm is selected, and both ends of the capillary tube 21 are sealed with oxyhydrogen flame welding, and one end of the capillary tube 21 is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube 21 is adapted to the high-pressure valve 41;

[0145] In this step, a 20-30 cm long high-pressure quartz capillary 21 is selected. Due to its material properties, this capillary 21 can withstand higher pressure while maintaining structural stability and transparency; hydrogen-oxygen flame is used to weld and seal both ends of the capillary 21, thereby ensuring the sealing of the capillary 21, preventing leakage of high-pressure gas, and also ensuring safety during the experiment; one end of the capillary 21 is bonded to a stainless steel sleeve of about 5 cm using epoxy resin glue. The epoxy resin glue has the characteristics of high bonding strength, small curing shrinkage, good chemical resistance, and excellent electrical insulation. These characteristics make the epoxy resin glue an ideal choice for bonding the high-pressure capillary to the stainless steel sleeve; through the stainless steel sleeve bonded with epoxy resin glue, the high-pressure quartz capillary 21 can be adapted to the high-pressure valve 41, so that the capillary 21 can be connected to the high-pressure system for transmission and experiment of high-pressure gas.

[0146] It should be emphasized that during the experiment, a quartz capillary containing a specific fluid sample is connected to the entire system, and the pressure is regulated in real time. The capillary 21 is bonded to the stainless steel sleeve using epoxy resin and connected to the high-pressure valve 41 through a nut to ensure that the high pressure inside the entire system can be transmitted to the interior of the capillary 21 without leakage.

[0147] Step S 220 : Removing the film on the outer wall of the capillary 21;

[0148] After the capillary 21 is firmly bonded to the sleeve, the film on the outer wall of the observation end of the capillary 21 is removed to make it completely transparent;

[0149] In this step, the transparency of the capillary 21 is crucial for observing the internal fluid state, performing spectral analysis and other experimental operations. Improved transparency helps to more accurately monitor and record changes during the experiment.

[0150] According to the material and characteristics of the film, choose a suitable chemical solvent or physical tool for removal. The chemical solvent needs to be able to dissolve the film without damaging the capillary itself, and the physical tool needs to be fine enough to avoid damaging the capillary.

[0151] Step S 230 : Capillary 21 conducts gas;

[0152] The closed end outside the sleeve is cut off, and a thinner gas-conducting capillary is used to insert the capillary 21 , and the entire pure carbon dioxide gas is introduced into the capillary 21 .

[0153] In this step, an opening is created so that a gas-conducting capillary can be inserted and connected to the capillary 21, thereby guiding pure carbon dioxide gas from a gas source or other container into the capillary 21. The gas-conducting capillary usually has a small inner diameter and is suitable for precisely controlling gas flow rate and pressure.

[0154] Step S 240 : mercury seal the capillary 21;

[0155] The gas-conducting capillary is pulled out, and an injection capillary connected to a mercury syringe is inserted into the interior of the capillary 21, and a 1-2 cm column of mercury is injected to seal the target gas.

[0156] In this step, the gas is sealed by injecting a mercury column into the capillary 21 to prevent gas leakage and the entry of external gas. Since mercury is liquid at room temperature, it has good sealing properties and can effectively isolate the gas in the capillary from the external environment.

[0157] Step S 250 : Capillary fixation;

[0158] The prepared capillary 21 is connected and fixed to the valve 41, and high-pressure water is used as a pressure transmission medium to push the mercury column to move and compress the pure carbon dioxide gas inside to achieve sensitive pressure regulation.

[0159] In this step, high-pressure water is used to push the mercury column, which can very accurately control the carbon dioxide gas pressure inside the capillary. By fixing the capillary and using high-pressure water as the pressure transmission medium, the stability and safety of the entire system can be ensured, preventing system damage or safety accidents caused by improper pressure control.

[0160] See also Figure 6 As shown, specifically to step S of the present invention 300 Among them, the method for preparing a capillary high-pressure chamber for a gas-liquid two-phase carbon dioxide fluid comprises:

[0161] Step S 310 : Initially prepare capillary 21;

[0162] A capillary tube 21 with a length of 20-30 cm is selected, and both ends of the capillary tube 21 are sealed with oxyhydrogen flame welding, and one end of the capillary tube 21 is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube 21 is adapted to the high-pressure valve 41.

[0163] In this step, the safety of the capillary under high pressure conditions can be ensured by oxyhydrogen flame welding and epoxy resin glue bonding to prevent bursting or leakage caused by excessive pressure; the high-pressure valve 41 is adapted so that the capillary 21 can be easily connected to the existing high-pressure experimental equipment, thereby improving the convenience of experimental operation.

[0164] Step S 320 : Removing the film on the outer wall of the capillary 21;

[0165] After the capillary 21 is firmly bonded to the sleeve, the film on the outer wall of the observation end of the capillary 21 is removed to make it completely transparent;

[0166] For experiments that require spectral analysis, the transparency of the capillary directly affects the collection of spectral signals. After removing the film, the scattering and absorption of light can be reduced, and the accuracy of spectral analysis can be improved.

[0167] Step S 330 : Capillary 21 conducts gas;

[0168] The closed end outside the sleeve is cut off, and a gas-conducting capillary is used to insert the capillary 21 , and the entire pure carbon dioxide gas is introduced into the capillary 21 .

[0169] In this step, pure carbon dioxide gas is introduced into the capillary 21 by using a gas-conducting capillary, thereby achieving precise control and safe introduction of the gas.

[0170] Step S 340 :Capillary conduction:

[0171] After the gas-conducting capillary is withdrawn, the liquid-conducting capillary connected to the target solution syringe is quickly inserted. When the front end of the liquid-conducting capillary reaches the predetermined position of the experiment, the solution is injected to seal the front gas, the liquid-conducting capillary is withdrawn, and the liquid injection capillary connected to the mercury syringe is inserted into the interior of the capillary 21 until the gas-liquid two-phase carbon dioxide fluid is introduced.

[0172] In this step, by precisely controlling the insertion of the liquid-conducting capillary and the injection of the solution, it is possible to ensure that the solution accurately reaches the predetermined position in the capillary 21; after the solution is injected to seal the front-end gas, the introduction of the mercury column can ensure the stability of the gas-liquid two-phase and prevent gas and liquid mixing or gas leakage.

[0173] Step S 350 : mercury seal the capillary 21;

[0174] The injection capillary is drawn out, and an injection capillary connected to a mercury syringe is inserted into the interior of the capillary 21, and a 1-2 cm column of mercury is injected to seal the internal gas-liquid two-phase carbon dioxide fluid, thereby forming a gas-liquid two-phase carbon dioxide capillary sample;

[0175] Step S 360 : Calculation of gas-liquid molar ratio:

[0176] The gas-liquid two-phase carbon dioxide capillary sample is set on the hot and cold stage 31, and the tip of the gas-liquid two-phase carbon dioxide capillary sample is placed under the microscope 12 to observe and determine the length ratio of the gas-liquid two-phase column at the corresponding temperature and pressure, and accurately calculate the molar ratio of the gas and the solution based on the gas state equation and the molar volume of the substance.

[0177] In this step, by placing the capillary sample on the hot / cold stage 31 and placing the tip under the microscope 12, the length ratio of the gas-liquid two-phase column can be observed, and the volume ratio of the gas phase and the liquid phase can be accurately measured using the magnification function of the microscope.

[0178] According to the ideal gas state equation pV = nRT, where p is pressure, V is volume, n is the amount of substance, R is the gas constant, and T is the thermodynamic temperature. Through this equation, the amount of substance in the gas can be calculated based on the known pressure, temperature, and volume.

[0179] The molar volume of a substance is the volume occupied by 1 mole of the substance at a certain temperature and pressure. With the molar volume known, the amount of the substance in the solution can be calculated.

[0180] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. An isotope measuring device for geological carbon-containing fluids, used for determining the composition-density-isotope of geological carbon-containing fluids, characterized in that: The isotope measuring device comprises: A reactor, comprising a capillary tube for containing the geological carbonaceous fluid and a heat-conducting silver cover for encapsulating the geological carbonaceous fluid, wherein the heat-conducting silver cover is located in the capillary tube so that the geological carbonaceous fluid forms a fluid inclusion, and the capillary tube is suitable for encapsulating the fluid inclusion; A temperature control system, used to simulate the actual temperature of the geological carbonaceous fluid reservoir and provide a set temperature range for the generation of the geological carbonaceous fluid; A pressure control system, used to simulate the real pressure environment of the geological carbonaceous fluid reservoir and provide a set pressure range for the generation of the geological carbonaceous fluid; The micro-Raman testing system is used to identify and analyze the spectral characteristics of various substances in the geological carbon-containing fluid, and then determine the isotope content of different component systems in the geological carbon-containing fluid.

2. The isotope measuring device for geological carbon-containing fluid according to claim 1, characterized in that: The temperature control system includes a hot and cold stage, a liquid nitrogen control subsystem and a thermocouple. The temperature control range of the hot and cold stage is -190-500°C. The thermocouple is used to control the temperature rise part of the hot and cold stage, and the liquid nitrogen control subsystem is used to control the temperature drop part of the hot and cold stage.

3. The isotope measuring device for geological carbon-containing fluid according to claim 1, characterized in that: The pressure control system includes a valve, a pressure sensor and a pressure pump, and the valve includes a first valve and a second valve that are connected to each other, the first inlet of the first valve is connected to the tip of the capillary, the first outlet of the first valve is connected to the second inlet of the second valve, the second outlet of the second valve is connected to the pressure pump, and the pressure sensor is also installed on the second valve.

4. The isotope measuring device for geological carbon-containing fluid according to claim 3, characterized in that: The booster pump is a manual or electric structure, and the pressure transmission medium of the booster pump is pure water; the valve is a #60-15HF2 model manufactured by HIP, and the upper pressure limit of the valve is 206MPa; the pressure sensor is a DP41-S-230 model manufactured by Omega.

5. The isotope measuring device for geological carbon-containing fluid according to claim 1, characterized in that: The micro-Raman testing system comprises: A laser light source for generating at least one laser beam; A spectrometer, used to identify and analyze the spectral characteristics of various substances in the fluid inclusions; A three-dimensional mobile platform, used for placing the reactor and suitable for adjusting the position of the capillary; A microscope is arranged above one side of the three-dimensional moving platform to observe the sample in the capillary.

6. The isotope measuring device for geological carbon-containing fluid according to claim 5, characterized in that: The laser light source is a diode-pumped solid-state laser; the spectrometer is a LabRAM HR800 laser Raman spectrometer.

7. A method for measuring isotopes of geological carbon-containing fluids, using the isotope measuring device for geological carbon-containing fluids according to any one of claims 1 to 6, characterized in that: The isotope measurement method comprises the steps of: Step S 100 : Carbon dioxide gas for preparing isotope standards; Step S 200 : A capillary high pressure chamber for preparing pure carbon dioxide gas on one of the capillaries; Step S 300 : Prepare a capillary high-pressure chamber for gas-liquid two-phase carbon dioxide fluid on another capillary: Step S 400 : The geological carbon-containing fluid samples in the capillary high-pressure cavity of the pure carbon dioxide gas and the capillary high-pressure cavity of the gas-liquid two-phase carbon dioxide fluid are tested and analyzed by micro-Raman spectroscopy.

8. The isotope measurement method of geological carbon-containing fluid according to claim 7, characterized in that: In step S 100 The method for preparing isotope standard carbon dioxide gas comprises: Step S 110 :Vacuum inside the capillary; Add phosphoric acid, carbonate reactant and desiccant into the capillary tube, open the valve and operate the vacuum pump to extract the internal air in the capillary tube; Step S 120 : Preparation of carbon dioxide gas; Close the valve and vacuum pump, and keep the vacuum inside the capillary. Open the phosphoric acid dropper bottle and gradually drip phosphoric acid into the carbonate powder to react chemically and generate a large amount of carbon dioxide gas. Step S 130 : Drying the liquid water mixed in the carbon dioxide gas; The carbon dioxide generated by phosphoric acid and carbonate powder is allowed to enter the desiccant along the pipeline in the capillary tube to remove liquid water mixed in from the phosphoric acid solution and the reaction process; Step S 140 : Vacuum to remove impurities; The dried and dehydrated carbon dioxide gas then enters a freezing tank filled with liquid nitrogen, and the valve and vacuum pump are opened to evacuate the gas. The carbon dioxide is frozen into a solid phase and remains in the capillary pipeline, and the mixed impurity gas is pumped out by the vacuum pump until all the generated carbon dioxide gas is frozen and purified into the pipeline of the liquid nitrogen tank, and then the valve and vacuum pump are closed; Step S 150 : Carbon dioxide purification; The liquid nitrogen freezing tank is removed, and the solid carbon dioxide frozen in the capillary pipeline is slowly heated up and restored to the gas phase, thereby entering the gas collecting device and being purified by removing water and impurities.

9. The isotope measurement method of geological carbon-containing fluid according to claim 7, characterized in that: In step S 200 Among them, the method for preparing a capillary high-pressure chamber for pure carbon dioxide gas comprises: Step S 210 :Preparation of capillary tube; A capillary tube with a length of 20-30 cm is selected, and both ends of the capillary tube are sealed with oxyhydrogen flame welding, and one end of the capillary tube is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube is adapted to the high-pressure valve; Step S 220 : Remove the film on the outer wall of the capillary; After the capillary tube is firmly fixed, the film on the outer wall of the observation end of the capillary tube is removed to make it completely transparent; Step S 230 : Capillary gas conduction; Cut off the closed end outside the sleeve, insert the capillary tube with a gas-conducting capillary tube, and introduce the entire pure carbon dioxide gas into the capillary tube; Step S 240 : Mercury seal the capillary; Pull out the gas-conducting capillary, insert an injection capillary connected to a mercury syringe into the capillary, and inject a 1-2 cm column of mercury to seal the target gas; Step S 250 : Capillary fixation; The prepared capillary is connected and fixed to the valve, and high-pressure water is used as the pressure transmission medium to push the mercury column to move and compress the pure carbon dioxide gas inside to achieve sensitive pressure regulation.

10. The isotope measurement method of geological carbon-containing fluid according to claim 7, characterized in that: In step S 300 Among them, the method for preparing a capillary high-pressure chamber for a gas-liquid two-phase carbon dioxide fluid comprises: Step S 310 :Preparation of capillary tube; A capillary tube with a length of 20-30 cm is selected, and both ends of the capillary tube are sealed with oxyhydrogen flame welding, and one end of the capillary tube is bonded to the sleeve with epoxy resin glue, and the other end of the capillary tube is adapted to the high-pressure valve; Step S 320 : Remove the film on the outer wall of the capillary; After the capillary tube is firmly fixed, the film on the outer wall of the observation end of the capillary tube is removed to make it completely transparent; Step S 330 : Capillary gas conduction; Cut off the closed end outside the sleeve, insert the capillary tube with a gas-conducting capillary tube, and introduce the entire pure carbon dioxide gas into the capillary tube; Step S 340 :Capillary conduction: After the gas-conducting capillary is withdrawn, the liquid-conducting capillary connected to the target solution syringe is quickly inserted. When the front end of the liquid-conducting capillary reaches the predetermined position of the experiment, the solution is injected to seal the front gas, the liquid-conducting capillary is withdrawn, and the liquid-injection capillary connected to the mercury syringe is inserted into the interior of the capillary until the gas-liquid two-phase carbon dioxide fluid is introduced; Step S 350 : Mercury seal the capillary; The injection capillary is drawn out, and an injection capillary connected to a mercury syringe is inserted into the capillary, and a 1-2 cm column of mercury is injected to seal the internal gas-liquid two-phase carbon dioxide fluid, thereby forming a gas-liquid two-phase carbon dioxide capillary sample; Step S 360 : Calculation of gas-liquid molar ratio: The gas-liquid two-phase carbon dioxide capillary sample is set up on a hot and cold stage, and the tip of the gas-liquid two-phase carbon dioxide capillary sample is placed under a microscope to observe and determine the length ratio of the gas-liquid two-phase column at the corresponding temperature and pressure, and accurately calculate the molar ratio of gas and solution based on the gas state equation and the molar volume of the substance.

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