Carbonate cluster isotope test pretreatment device and test method

Abstract

The invention provides a carbonate cluster isotope test pretreatment device and a test method. The device comprises an acidolysis reaction unit, a gas purification unit and a gas collection unit which are sequentially connected through a pipeline, and a balance gas unit; the acidolysis unit comprises a closed acidolysis reactor and a common acid bath acidolysis reactor; the closed acidolysis reactor and the common acid bath acidolysis reactor are connected in parallel; the first low vacuum pumping device is provided with a control valve and is connected with the acidolysis unit or the gas balancing unit; the second low-vacuum pumping device is provided with a control valve, and the second low-vacuum pumping device is connected with the first high-vacuum pumping device and is connected with the gas purification unit; a first high-vacuum pipeline is arranged on the pipeline, comprises a third low-vacuum pumping device and a second high-vacuum pumping device, and is connected with the acidolysis unit or the gas balancing unit; and the low vacuum pumping device is an oil-free system. The device disclosed by the invention is high in carbonate cluster isotope testing precision.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and gas exploration, and in particular relates to a carbonate cluster isotope testing device and a testing method. Background Art

[0002] Marine carbonate reservoirs account for about 20% of the world's total sedimentary rock area, and the oil and gas production of marine carbonate oil and gas fields accounts for about 66% of the world's oil and gas production, which is a key area of ​​oil and gas exploration and development. Marine carbonate reservoir prediction is one of the main scientific issues facing marine strata oil and gas exploration, and it is also one of the "bottleneck" technologies that restrict marine carbonate strata oil and gas exploration. Among them, paleotemperature reconstruction is a key issue and difficulty in the study of diagenetic environment in marine carbonate reservoir prediction. At present, the main methods for restoring paleotemperature for carbonate reservoirs are carbonate mineral oxygen isotope (δ 18 O) temperature measurement, fluid inclusion temperature measurement, Mg / Ca ratio temperature measurement of foraminifera, etc. Among them, oxygen isotope is one of the most commonly used "geological thermometers"; but δ 18 The application of oxygen to deep-time paleotemperature research faces huge challenges, mainly in three aspects: (1) the lack of reliable paleontological fossils as carriers of isotope preservation; (2) the controversy over the reliable oxygen isotope composition of seawater of the same period; and (3) strong diagenetic transformation.

[0003] In recent years, carbonate cluster isotopes (Δ 47 The rapid development of the ) thermometer has the biggest advantage over the traditional carbonate rock oxygen isotope thermometer: it is a single-phase mineral thermometer, independent of the fluid when the carbonate is formed, and does not require information on the oxygen isotope composition of the fluid. As a new type of accurate thermometer, its emergence will provide more possibilities for the reconstruction of paleotemperature of marine carbonate rocks.

[0004] Cluster isotopes are isotopes formed when two or more atoms in an isotopologue are replaced by their corresponding heavy isotopes. 47 ) refers to the carbonate ion (CO3 2- )middle 13 C, 17 O and 18 O heavy isotope multiple substitution 12 C and 16 O, consisting of four isotopes 13 C 16 O2 18 O. 12 C 16 O 17 O 18 O. 12 C 16 O 17 O2 and13 C 17 O3 composition, limited by the current testing technology conditions, carbonate ions (CO3 2- ) cluster isotopes cannot be measured directly, and carbon dioxide gas needs to be produced by acid hydrolysis, and then the carbon dioxide gas cluster isotopes are measured. Based on the fact that the carbon dioxide gas produced during the acid hydrolysis of carbonate is proportional to the isotopologue content of carbonate minerals, the abundance of the isotopologue with a mass number of 47 in the acid hydrolysis product carbon dioxide gas and the value corrected by the acid fractionation coefficient can represent the carbonate cluster isotope (Δ 63 ).

[0005] The carbonate cluster isotope thermometer was formally proposed by John Eiler's research group at California Institute of Technology in 2006 (Ghosh et al., 2006). It is mainly based on the difference in abundance between the carbon dioxide gas isotopologue with a mass number of 47 and its "random distribution" state (Δ 47 ) and temperature. 13 C- 18 The abundance of cluster isotopologues with O bonds (about 45 ppm) accounts for nearly 97% of all cluster isotopologues with a mass number of 47. 13 C- 18 The isotopologue abundance of the O-bonded carbon dioxide gas cluster represents the abundance of all carbon dioxide gases with a mass number of 47. Since the content of the carbonate cluster isotope thermometer test object is about 45ppm, which is 2 to 3 orders of magnitude lower than the content of the conventional carbonate rock carbon and oxygen isotope test object, strict requirements are imposed on each link in the test process. At present, there is still a lot of room for improvement in the carbonate cluster isotope pretreatment device in terms of vacuum system (the fore pump is an oil pump), balance gas preparation method and acid hydrolysis reaction, which is mainly reflected in the following three aspects: (1) The oil vapor generated by the oil pump in the vacuum system of the existing carbonate pretreatment device will affect the test accuracy; (2) The systematic error in the balance gas preparation step needs to be reduced; (3) At present, there is only one of the closed or open acid hydrolysis reaction methods in the carbonate pretreatment device. However, these two acid hydrolysis methods are very important for carbonate cluster testing. The cluster data based on the two acid hydrolysis reactions can verify each other and provide a means for the correction of phosphoric acid fractionation coefficient. Therefore, it is of great significance to design a carbonate cluster isotope pretreatment device with high standards and establish a corresponding carbonate cluster isotope test method. Summary of the invention

[0006] The object of the present invention is to provide a carbonate cluster isotope testing device and a testing method to improve the testing accuracy of carbonate cluster isotope testing.

[0007] In order to achieve the above object, the present invention provides a carbonate cluster isotope test pretreatment device, which comprises:

[0008] An acidolysis reaction unit, a gas purification unit, a gas collection unit, and a balance gas unit connected in sequence through pipelines;

[0009] The acidolysis unit comprises a closed acidolysis reactor and a common acid bath acidolysis reactor; the closed acidolysis reactor and the common acid bath acidolysis reactor are connected in parallel;

[0010] and a first vacuum pumping device with a control valve, connected to the acid hydrolysis unit or the balancing gas unit;

[0011] and a second low vacuum pumping device with a control valve, the second low vacuum pumping device being connected to the first high vacuum pumping device and connected to the gas purification unit;

[0012] A first high vacuum pipeline is arranged on the pipeline, and the first high vacuum pipeline includes a third low vacuum pumping device and a second high vacuum pumping device; the first high vacuum pipeline is connected to the acidolysis unit or the balancing gas unit; the first low vacuum pumping device, the second low vacuum pumping device and the third low vacuum pumping device are oil-free systems.

[0013] In the present invention, "low vacuum" means a vacuum degree ≥ 7×10 -3 mbar; "high vacuum" refers to a vacuum degree of 7×10 - 3 mbar~1×10 -4 mbar.

[0014] Compared with the prior art, the carbonate cluster isotope test pretreatment device of the present invention provides an oil-free vacuum system on the one hand, and is compatible with a balance gas preparation device on the other hand, providing a platform for establishing an empirical conversion equation with high precision.

[0015] In the present invention, the "oil-free system" means that the vacuum unit is oil-free, including low vacuum and high vacuum devices, and the oil-free valve is that the components of the pipeline connection part (mainly the control valve) are oil-free. At the same time, the valve of the present invention is also oil-free. The inventor of the present invention has found through research and exploration that if the vacuum unit contains oil, it will have a significant negative impact on the test accuracy of carbonate cluster isotopes, so the above improvements are made relative to the existing process.

[0016] In some embodiments of the present invention, the gas purification unit comprises a plurality of condensing devices connected in series. Preferably, the condensing devices comprise cold traps and cold fingers.

[0017] Preferably, the device has at least 4 groups of condensing devices, and each group of condensing devices is preferably connected via a control valve.

[0018] Preferably, the cold trap is placed in liquid nitrogen, -90°C alcohol or a methanol-liquid nitrogen mixture.

[0019] Preferably, the cold trap comprises a porapak trap, wherein the porapak trap filler is 100 mesh Porapak TMQ porous ethyl styrene, divinyl benzene polymer and a small amount of silver wire, and the length is about 15 cm. The specific ratio of each filler can be adjusted according to the process conditions.

[0020] In the present invention, the balance gas unit also has a carbon dioxide gas storage, purification transfer and sealing component in the heating gas and water balance gas preparation device; and a carbon dioxide gas temperature rebalancing component in the heating gas and water balance gas preparation device. CN112857957A provides a balance gas preparation device for carbonate cluster isotope testing, and those skilled in the art can build these basic components of the balance gas unit according to the disclosed content of the patent.

[0021] In a preferred embodiment, the number of reaction interfaces of the closed acidolysis reactor is more than one, and the reaction interfaces are in parallel relationship. For example, the number of reaction interfaces can be 2, 3, 4, or 5. By increasing the reaction interfaces of the closed acidolysis reactor, the device of the present invention can improve the test efficiency.

[0022] In a preferred embodiment, the number of reaction interfaces of the closed acidolysis reactor is 5.

[0023] Preferably, the gas collection unit can be connected to one of the reaction interfaces, and the other interfaces are kept closed by the control valve. Further preferably, the lower end of the control valve is connected to a quick connector, preferably an Ultra-Torr.

[0024] In a preferred embodiment, the pumping speed of the first low vacuum device is 8 to 11.4 m / s. 3 / h, the rated speed is 1500-1800rpm, and the power is 600-660W; preferably, the pumping speed of the second low vacuum pumping device and the third low vacuum pumping device is independently 0.8-1.0m 3 / h, the rated speed is 1600-1800 rpm, and the power is 21-24 W. Preferably, the pumping speed, rated speed, and power of the second and third vacuum pumping devices are kept consistent.

[0025] Preferably, the first vacuum pumping device, the second vacuum pumping device and / or the third vacuum pumping device are a backing pump or a diaphragm pump. Preferably, the model of the backing pump vacuum pump is an nXDS6i (or above 6i) Edwards dry pump.

[0026] In a preferred embodiment, the rotation speed of the first high vacuum device is 85000-90000 rpm, and the pumping speed is 66-71 L / s; preferably, the rotation speed of the second high vacuum device is 85000-90000 rpm, and the pumping speed is 66-71 L / s. Preferably, the first high vacuum device and / or the second vacuum device is a molecular pump. Preferably, the model of the molecular pump vacuum device is Hipase80wit Pfeiffer molecular pump, and the corresponding controller is pfeiffer TC110 / TC80.

[0027] In a preferred embodiment, the first high vacuum pumping device P1 is connected to the second low vacuum pumping device L2, and the second high vacuum pumping device P2 is connected to the third low vacuum pumping device L3. The connection method is preferably through a rubber tube.

[0028] Preferably, the molecular pump is connected to the bellows via a NW25 flange, and the other end of the bellows is connected to a high vacuum pipeline of the cluster isotope pretreatment device.

[0029] In a preferred embodiment, the closed acid hydrolysis reactor comprises a sample holding tube, a reaction bottle, and a vacuum quick connector. Preferably, the sample holding tube is made of quartz glass, or other materials that are considered to have good corrosion resistance in the process. Preferably, the sample holding tube is in the shape of an open cylinder with a wall thickness of 0.2 to 0.4 mm, a diameter of 5 to 7 mm, and a height of 16 to 20 mm. The reaction bottle is preferably made of quartz glass. The reaction bottle preferably has a sealing ring for providing a sealed environment.

[0030] In a preferred embodiment, the common acid bath acidolysis reactor comprises an acid holding bottle, a sample tray, a stainless steel cavity, a rotating joystick, a heating unit and a vacuum display unit. Preferably, the acid holding bottle has a rotor, preferably made of polytetrafluoroethylene. Preferably, the sample tray is made of stainless steel. Preferably, the heating unit comprises a heating belt and a heating electric furnace. Preferably, the vacuum display unit comprises a Penning high vacuum gauge ( Figure 1 G2 vacuum gauge) is used to monitor the vacuum degree at the acid bath acidolysis reaction end in real time.

[0031] In some embodiments of the present invention, the schematic diagram of the device of the present invention is as follows Figure 1 shown.

[0032] According to another aspect of the present invention, a carbonate cluster isotope testing method is provided, wherein the testing method uses the above-mentioned carbonate cluster isotope testing pretreatment device for pretreatment.

[0033] In a preferred embodiment, the testing method comprises the following steps:

[0034] Instrument calibration;

[0035] The equilibrated CO2 gases at 1000°C, 50°C and 25°C are respectively subjected to a first purification process and a first collection process, and then carbonate cluster isotope testing is performed to calibrate the instrument;

[0036] Carbonate mineral testing;

[0037] Carrying out a closed acidolysis reaction or a common acid bath acidolysis reaction with a carbonate mineral and phosphoric acid to obtain a reaction product, the reaction product undergoing a second purification treatment and a second collection treatment, and then conducting a carbonate cluster isotope test;

[0038] Preferably, the temperature of the closed acid hydrolysis reaction is 25 to 90°C;

[0039] Preferably, the temperature of the common acid bath acidolysis reaction is 25-90°C.

[0040] In a preferred embodiment, the testing method further comprises:

[0041] Before the first purification treatment, the equilibrated CO2 gas at 1000°C is rapidly cooled; preferably, the equilibrated CO2 gas at 1000°C is cooled to 5-30°C within 30 seconds.

[0042] In a preferred embodiment, the rapid cooling is achieved by a cooling assembly, which includes an air compressor and a dust blower. A typical structural diagram is shown in FIG. Figure 2 shown.

[0043] In a preferred embodiment, the air compressor has a gas tank capacity of not less than 25 liters and an air outlet speed of not less than 160 liters / minute. The air compressor selected according to the above preferred conditions can perform air blowing faster, so that the temperature can be quickly reduced, in order to achieve the carbon dioxide cluster isotope Δ 47 Freezing at 1000°C provides the basis.

[0044] In the present invention, the term "freezing" refers to the carbon dioxide cluster isotope Δ 47 The cluster isotope Δ during rapid cooling from 1000℃ 47 It remains unchanged, as if frozen, so that the carbon dioxide cluster isotope Δ at approximately 1000°C can be measured. 47The slope consistency of the linear equation of the equilibrium gas cluster isotopes tested based on the above-mentioned rapid cooling method is significantly improved, and the test accuracy is improved.

[0045] In some embodiments of the present invention, before the rapid cooling process, the equilibrated CO2 gas at 1000°C is kept at 1000°C for more than 2 hours.

[0046] The specific method of using balance gas to calibrate the instrument has been recorded. Typically, those skilled in the art can refer to CN112857957A for implementation.

[0047] In some embodiments of the present invention, the temperature of the closed acid hydrolysis reaction and the common acid bath acid hydrolysis reaction may be the same. In some embodiments of the present invention, the temperature of the closed acid hydrolysis reaction and the common acid bath acid hydrolysis reaction may be different.

[0048] In a preferred embodiment, the concentration of phosphoric acid in the closed acidolysis reaction and the common acid bath acidolysis reaction is 104%. In the present invention, unless otherwise specified, all concentrations involved are mass concentrations.

[0049] The concentration of phosphoric acid purchased on the market is generally 99%. It is necessary to adjust the concentration of 99% phosphoric acid to 104% by heating or adding phosphorus pentoxide. In some embodiments of the present invention, preferably, the heating temperature is 200-250°C, and stirring is continued until the phosphoric acid concentration reaches 104%. When purchasing phosphoric acid, the impurity content should be considered, and phosphoric acid with a low impurity content should be selected. In some embodiments of the present invention, the phosphoric acid with a concentration of 104% is prepared by adding phosphorus pentoxide. The phosphoric acid with a concentration of 99% should be transferred to a conical flask, and while adding phosphorus pentoxide, the outer wall of the conical flask is cooled with running water and continuously shaken until the concentration reaches 104%. The prepared phosphoric acid bottle mouth is wrapped with tin foil, and the temperature is cooled to room temperature and placed in a desiccator for storage.

[0050] In a preferred embodiment, the carbonate mineral is calcite. Preferably, calcite is a standard sample. Preferably, the calcite standard sample ETH-4 is a calcite standard sample developed by the Swiss Federal Institute of Technology.

[0051] In a preferred embodiment, the purification process includes using multiple condensation devices to remove water and impurities in the collected carbon dioxide gas, and using a porapak trap to remove pollutants such as organic matter and sulfur.

[0052] In a preferred embodiment, the test is performed using a dual-path process of a gas stable isotope mass spectrometer.

[0053] In a preferred embodiment, the testing method comprises:

[0054] Edit the sequence test program, select 6 to 8 acquisitions test units, each of which includes 12 to 16 test cycles; preferably, each test lasts 2.5 to 3 hours.

[0055] In a preferred embodiment, after the test is completed, data correction processing is performed; preferably, the data correction processing includes linear correction and acid fractionation coefficient correction to obtain the final Δ 47 value.

[0056] Compared with the prior art, the present invention significantly improves the testing accuracy of carbonate cluster isotopes. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 A schematic diagram of a carbonate cluster isotope test pre-treatment device is shown.

[0058] Figure 2 A schematic structural diagram of a cooling assembly is shown.

[0059] Description of main reference numerals:

[0060] Figure 1 In the figure, 1 is the first control valve, 2 is the second control valve, 2* is the reaction interface, 3 is the third control valve, 3* is the reaction interface, 4 is the fourth control valve, 4* is the reaction interface, 5 is the fifth control valve, 5* is the reaction interface, 6 is the sixth control valve, 6* is the reaction interface, 7 is the seventh control valve, 8 is the eighth control valve, 9 is the ninth control valve, 10 is the tenth control valve, 11 is the eleventh control valve, 12 is the twelfth control valve, 13 is the thirteenth control valve, 14 is the fourteenth control valve, 15 is the fifteenth control valve, 16 is the sixteenth control valve, 17 is the seventeenth control valve, 18 is the eighteenth control valve, 19 is the nineteenth control valve, 20 is the twentieth control valve, 21 is the first high vacuum pipeline, 22 is the low vacuum pipeline, 23 is the second high vacuum pipeline, 24 is the first gas sample collection bottle, 25 is the common acid bath acidolysis reactor, 26 is the porapak trap; 27 is the second gas sample collection bottle;

[0061] 101 is a first cold trap, 102 is a second cold trap, 103 is a third cold trap, 104 is a fourth cold trap, and 105 is a fifth cold trap;

[0062] G1 is the first vacuum gauge, G2 is the second vacuum gauge, G3 is the third vacuum gauge; G4 is a pressure sensor; L1-L4 are the first low vacuum device to the fourth low vacuum device respectively, P1 is the first high vacuum device, and P2 is the second high vacuum device. DETAILED DESCRIPTION

[0063] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0064] Example 1

[0065] This embodiment provides a carbonate cluster isotope test pretreatment device, the structure of which is as follows: Figure 1 As shown, the device comprises: an acid hydrolysis reaction unit, a gas purification unit, a gas collection unit, and a balance gas unit; wherein:

[0066] The acidolysis reaction unit includes a closed acidolysis reactor and a common acid bath acidolysis reactor 25; the closed acidolysis reactor and the common acid bath acidolysis reactor 25 are connected in parallel; the closed acidolysis reactor includes a fifth cold trap 105, a second control valve 2 (provided with a reaction interface 2*), a third control valve 3 (provided with a reaction interface 3*), a fourth control valve 4 (provided with a reaction interface 4*), a fifth control valve 5 (provided with a reaction interface 5*), a sixth control valve 6 (provided with a reaction interface 6*), and a seventh control valve 7 connected in series; an eighth control valve 8 and a second vacuum gauge G2 are provided at the outlet of the common acid bath acidolysis reactor 25;

[0067] The gas purification unit includes a tenth control valve 10, a first cold trap 101, an eleventh control valve 11, a second cold trap 102, a porapak trap 26, and a twelfth control valve 12 connected in sequence, wherein a first vacuum gauge G1 is provided on a connecting pipeline between the second cold trap 102 and the porapak trap 26;

[0068] The gas collection unit includes: a third cold trap 103, a fourteenth control valve 14, an eighteenth control valve 18, a seventeenth control valve 17, a fourth cold trap 104, and a twentieth control valve 20 connected in sequence; the third cold trap 103 and the fourth cold trap 104 each have an outlet connected to a second high vacuum pipeline 23, and the second vacuum pipeline 23 is provided with a first high vacuum device P1 and a second low vacuum device L2;

[0069] The device of the present invention further includes a pressure sensor G4. One end of the pressure sensor G2, one end of the thirteenth control valve 13, one end of the twelfth control valve 12, and one end of the fifteenth control valve 15 are connected together.

[0070] One end of the seventh control valve 7, one end of the eighth control valve 8, one end of the ninth control valve 9, and one end of the tenth control valve 10 are connected together;

[0071] The device also includes: a first low vacuum device L1 connected to the ninth control valve 9, and a third vacuum gauge G3 is provided on the connecting pipeline between the two;

[0072] The pipeline is provided with a first high vacuum pipeline 21, and the first high vacuum pipeline 21 is connected to the acidolysis reaction unit or the balance gas unit through a first control valve 1; the first control valve 1 is also connected to the fifth cold trap 105;

[0073] The first high vacuum pipeline 21 includes a third low vacuum pumping device L3 and a second high vacuum pumping device P2;

[0074] The device further includes a fourth low vacuum device L4, which is connected to the first high vacuum pipeline 21 through a sixteenth control valve 16; and one end is connected to the fourteenth control valve 14, and the other end is connected to the eighteenth control valve 18;

[0075] The first low-vacuum pumping device L1 , the second low-vacuum pumping device L2 , the third low-vacuum pumping device L3 , and the fourth low-vacuum pumping device L4 are all oil-free systems.

[0076] The device also includes a first gas sample collection bottle 24. The gas sample collection bottle 24 is connected to any one of the reaction interface 2*, reaction interface 3*, reaction interface 4*, reaction interface 5*, and reaction interface 6* through a quick connector, such as the reaction interface 3*, and the gas collection bottle 24 contains phosphoric acid and carbonate samples;

[0077] The device further comprises a second gas collecting bottle 27 connected to one end of the eighteenth control valve end 18 .

[0078] This embodiment also provides a carbonate cluster isotope testing method, which uses the above-mentioned pretreatment device for pretreatment, specifically including:

[0079] Instrument calibration

[0080] (1) 1000℃ heating gas preparation

[0081] 1) Using a balance gas preparation unit to transfer and purify 10-15 μmol of pure carbon dioxide gas into a quartz glass tube. Before use, the quartz glass tube is calcined at 1000° C. in a muffle furnace for more than 2 hours and sealed with a high-temperature flame.

[0082] The prepared carbon dioxide gas is placed in a muffle furnace and calcined at 1000℃ for more than 2 hours. Prepare a rapid cooling device (install the air compressor and gas pipeline, connect the dust blower to the pipeline terminal, and turn on the power); fill the 25-liter air compressor with gas before use, adjust the gas outlet speed to 160 liters / minute, close the muffle furnace at 1000℃, quickly take out the carbon dioxide-containing quartz glass tube with a special clamp, place and fix it on a tray, and use the air generated by the dust blower to cool the quartz glass tube from 1000℃ to room temperature within 30 seconds.

[0083] 2) Connect the quartz glass tube containing 1000℃ heating gas to the glass breaking device Cracker, and connect the other end of the Cracker to one of the five quick interfaces of the closed reaction end unit. For example, select reaction interface 3*, and keep the other reaction interfaces closed through control valves. Open the third control valve 3, the seventh control valve 7, and the ninth control valve 9, and close the fourth control valve 4, the fifth control valve 5, and the sixth control valve 6. Use the foreline pump to evacuate the vacuum first, and wait until the vacuum is better than 3×10 -2 mbar, close the seventh control valve 7 and the ninth control valve 9, open the first control valve 1, and continue to evacuate with the molecular pump until the vacuum reaches 4×10 -4 mbar, in Figure 1 Liquid nitrogen is placed at the position of the first cold trap 101, the seventh control valve 7 and the tenth control valve 10 are opened, the first control valve 1 and the eleventh control valve 11 are closed, and the 1000° C. carbon dioxide heating gas in the quartz glass tube is crushed by a Cracker crushing device, and the carbon dioxide gas is transferred to the first cold trap 101.

[0084] (2) Carbon dioxide gas purification and transfer

[0085] like Figure 1 As shown:

[0086] 1) The carbon dioxide gas is transferred from the first cold trap 101 to the second cold trap 102, and water and impurity gases are removed for the first time, and the amount of carbon dioxide gas Q1 is recorded;

[0087] 2) Carbon dioxide gas passes through the porapak trap to remove pollutants such as organic matter and sulfur;

[0088] 3) Record the amount of carbon dioxide gas Q2, remove water and impurities for the second time and transfer it to the gas sample collection bottle.

[0089] The carbon dioxide gas is transferred from the first cold trap 101 to the second cold trap 102. The first dehydration and impurity removal and recording of the carbon dioxide gas amount Q1 specifically include:

[0090] Close the tenth control valve 10 and the eleventh control valve 11 on both sides of the first cold trap 101, remove the liquid nitrogen and replace it with an alcohol-liquid nitrogen mixture at a temperature of -90°C, and record the amount of carbon dioxide gas Q1;

[0091] Close the twelfth control valve 12 on the left side of the second cold trap 102, put liquid nitrogen on the second cold trap 102, open the eleventh control valve 11, and transfer the carbon dioxide gas from the first cold trap 101 to the second cold trap 102; after the transfer is completely closed, the eleventh control valve 11 will remain in the first cold trap 101, and the first water vapor removal will be completed. Open the twelfth control valve 12 to extract the impurities for 3 minutes, complete the first impurity removal, and close the twelfth control valve 12.

[0092] 2) The carbon dioxide gas is passed through the Porapak trap 26 to remove pollutants such as organic matter and sulfur, which specifically includes: closing the fourteenth control valve 14 and the fifteenth control valve 15 on both sides of the third cold trap 103, putting liquid nitrogen on the third cold trap 103, stabilizing for 2 minutes, removing the liquid nitrogen at the second cold trap 102, opening the twelfth control valve 12, and slowly transferring the carbon dioxide gas to the third cold trap 103 via the Porapak trap 26, the transfer time is 30 minutes, and then placing the -90°C alcohol liquid nitrogen mixture at the fourth cold trap 104, opening the fourteenth control valve 14, and continuing the transfer for 15 minutes to complete the removal of pollutants such as organic matter and sulfur.

[0093] The packing of the Porapak trap 26 is 100 mesh PorapakTMQ porous ethylstyrene, divinylbenzene polymer and a small amount of silver wire, and the length is about 15 cm.

[0094] 3) Record the amount of carbon dioxide gas Q2, remove water and impurities for the second time and transfer to the second gas sample collection bottle 27 gas sample collection bottle; specifically include:

[0095] After all the carbon dioxide gas has been transferred to the third cold trap 103, close the twelfth control valve 12, the fourteenth control valve 14 and the fifteenth control valve 14, remove the -90°C alcohol-liquid nitrogen mixture at the fourth cold trap 104, replace the liquid nitrogen at the third cold trap 103 with a -90°C alcohol-liquid nitrogen mixture, record the amount of carbon dioxide gas Q2 in the third cold trap 103, and put liquid nitrogen on the second gas sample collection bottle 27.

[0096] Open the seventeenth control valve 17, and transfer the carbon dioxide gas from the fourth cold trap 103 to the second gas sample collecting bottle 27. After the carbon dioxide gas is completely transferred, open the nineteenth control valve 19, and further remove the impurities for 2 minutes. Then close the seventeenth control valve 17 and the nineteenth control valve 19, close the gas sample collecting bottle, and the carbon dioxide gas collection is completed. Remove the liquid nitrogen and the second gas sample collecting bottle 27.

[0097] (3) Cluster isotope testing:

[0098] 1) The second gas sample collection bottle 27 filled with carbon dioxide gas is connected to the gas stable isotope mass spectrometer dual-path system process, and the carbon dioxide gas is introduced into the left bellow, and the reference gas is introduced into the right bellow. Specifically, the entire dual-path system is evacuated, first with the fore pump, and then switched to the molecular pump for 3 minutes. The sample carbon dioxide gas is transferred to the left bellow of the mass spectrometer dual-path system, and the right bellow is introduced with a reference gas of substantially the same amount as the left bellow, and the gas pressure on both sides is adjusted to balance.

[0099] 2) Edit the analysis test program to conduct cluster isotope (Δ47) testing, specifically including: edit the sequence test program, select 8 acquisitions test units, each acquisition consists of 14 cycles, start the program for analysis testing, and record high voltage and magnetic field data at the same time. The test time is about 3 hours.

[0100] 3) Cluster isotope (Δ47) data correction processing specifically includes:

[0101] The raw test data was imported into the eastope special software for cluster isotope (Δ47) data processing, and the Δ47-raw value of carbon dioxide gas was calculated. Then, linear correction and acid fractionation coefficient correction (fractionation coefficient was 0.092‰) were performed to obtain the Δ47 value of cluster isotope of 1000℃ heated gas.

[0102] Carbonate Mineral Testing

[0103] (1) Sample acid hydrolysis reaction

[0104] The acid hydrolysis reaction of calcite standard sample ETH-4 includes two methods: closed acid hydrolysis reaction and common acid bath acid hydrolysis reaction.

[0105] 1) Closed acid hydrolysis reaction: Weigh 8 mg of calcite standard sample ETH-4 and place it in a sample holding tube. Use a pipette to transfer 3 ml of 104% phosphoric acid to the bottom of the gas sample collection bottle. Tilt the sample holding tube into the gas sample collection bottle. Be careful not to let the 104% phosphoric acid contact the calcite standard sample ETH-4 in the holding tube. Connect the gas sample collection bottle filled with calcite standard sample ETH-4 and 104% phosphoric acid to the closed reaction unit of the carbonate pretreatment system; Figure 1 As shown: If the reaction interface 2* terminal is connected, open the second control valve 2, the seventh control valve 7, and the ninth control valve 9, close the fourth control valve 4, the fifth control valve 5, and the sixth control valve 6, and use the foreline pump to evacuate the vacuum until the vacuum is better than 3×10 -2 mbar, close the seventh control valve 7 and the ninth control valve 9, open the first control valve 1, and continue to evacuate with the molecular pump until the vacuum reaches 4×10 - 4mbar, close the second control valve 2, close the gas sample collection bottle to keep it in a high vacuum state, then remove the gas sample collection bottle, and keep it vertical to prevent the phosphoric acid at the bottom of the collection bottle from contacting the calcite standard ETH-4. Place the vacuumed gas sample collection bottle in a water bath at 90°C. Note that the bottle mouth should be 4 cm away from the water surface and the bottle mouth should not contact the water. After the gas sample collection bottle and the water bath set temperature are balanced, tilt the gas sample collection bottle to allow the carbonate sample to react with phosphoric acid for 30 minutes. After the reaction is complete, reconnect the gas sample collection bottle to the closed reaction end process and repeat the above vacuuming sequence to 4×10 -4 mbar, open the second control valve 2, cover the first cold trap 101 with liquid nitrogen, open the gas sample collection bottle, and transfer all the carbon dioxide gas to the first cold trap 101.

[0106] The closed reaction end unit has 5 quick interfaces. The gas sample collection bottle can be connected to one of the interfaces, and the other interfaces are kept closed by control valves.

[0107] 2) Common acid bath acidolysis reaction: Weigh 8 mg of calcite standard sample ETH-4 and place it in a sample holding tube, and place the holding tube in the sample tray of the common acid bath test device. Use a pipette to transfer 10 ml of 104% phosphoric acid to the bottom of the acid holding bottle, and connect the acid holding bottle to the common acid bath test device and keep it sealed. Figure 1 As shown: the common acid bath test device and the first cold trap 101 are connected with a stainless steel pipeline, the first control valve 1, the second control valve 2, the third control valve 3, the fourth control valve 4, the fifth control valve 5, the sixth control valve 6, the seventh control valve 7 and the tenth control valve 10 are closed, and the common acid bath test device is evacuated with a fore-stage pump. When the vacuum is better than 4×10 -1 mbar (when the reaction temperature is 90°C), close the ninth control valve 9, open the first control valve 1 and the seventh control valve 7, and use a molecular pump to evacuate. When the vacuum is better than 8×10 -2 mbar, close the seventh control valve 7, open the tenth control valve 10, put liquid nitrogen on the first cold trap 101, rotate the control rod to let the calcite standard ETH-4 fall into the acid holding bottle and react with phosphoric acid at 90°C, react for 30 minutes, and all the generated carbon dioxide gas is transferred to the first cold trap 101.

[0108] (2) Carbon dioxide gas purification and transfer

[0109] like Figure 1 As shown:

[0110] 1) The carbon dioxide gas is transferred from the first cold trap 101 to the second cold trap 102, and water and impurity gases are removed for the first time, and the amount of carbon dioxide gas Q1 is recorded;

[0111] 2) Carbon dioxide gas passes through the porapak trap to remove pollutants such as organic matter and sulfur;

[0112] 3) Record the amount of carbon dioxide gas Q2, remove water and impurities for the second time and transfer it to the gas sample collection bottle.

[0113] The carbon dioxide gas is transferred from the first cold trap 101 to the second cold trap 102. The first dehydration and impurity removal and recording of the carbon dioxide gas amount Q1 specifically include:

[0114] ① Close the tenth control valve 10 and the eleventh control valve 11 on both sides of the first cold trap 101, remove the liquid nitrogen and replace it with an alcohol-liquid nitrogen mixture at a temperature of -90°C, and record the amount of carbon dioxide gas Q1;

[0115] ② Close the twelfth control valve 12 on the left side of the second cold trap 102, put liquid nitrogen on the second cold trap 2, open the eleventh control valve 11, and transfer the carbon dioxide gas from the first cold trap 101 to the second cold trap 102; after the transfer is completely closed, the eleventh control valve 11 remains in the first cold trap 101, and the first water vapor removal is completed. Open the twelfth control valve 12 to extract the impurities for 3 minutes, complete the first impurity removal, and close the twelfth control valve 12.

[0116] 2) The carbon dioxide gas is passed through the Porapak trap to remove pollutants such as organic matter and sulfur, which specifically includes: closing the fourteenth control valve 14 and the fifteenth control valve 15 on both sides of the third cold trap 103, putting liquid nitrogen on the third cold trap 103, stabilizing for 2 minutes, removing the liquid nitrogen at the second cold trap 102, opening the twelfth control valve 12, and slowly transferring the carbon dioxide gas to the third cold trap 103 via the Porapak trap 26, the transfer time is 30 minutes, and then placing the -90°C alcohol liquid nitrogen mixture at the cold trap 104, opening the fourteenth control valve 14, and continuing the transfer for 15 minutes to complete the removal of pollutants such as organic matter and sulfur.

[0117] The packing of the Porapak trap 26 is 100 mesh PorapakTMQ porous ethylstyrene, divinylbenzene polymer and a small amount of silver wire, and the length is about 15 cm.

[0118] 3) Record the amount of carbon dioxide gas Q2, remove water and impurities for the second time and transfer to the gas sample collection bottle, specifically including:

[0119] ① After all the carbon dioxide gas has been transferred to the third cold trap 103, close the twelfth control valve 12, the fourteenth control valve 14 and the fifteenth control valve 15, remove the -90°C alcohol-liquid nitrogen mixture at the fourth cold trap 104, replace the liquid nitrogen at the third cold trap 103 with a -90°C alcohol-liquid nitrogen mixture, record the amount of carbon dioxide gas Q2 in the third cold trap 103, and put liquid nitrogen on the gas sample collection bottle.

[0120] ② Open the seventeenth control valve 17, and the carbon dioxide gas is transferred from the third cold trap 103 to the gas sample collection bottle. After the carbon dioxide gas is completely transferred, open the nineteenth control valve 19, and further remove the impurities for 2 minutes. Then close the seventeenth control valve 17 and the nineteenth control valve 19, close the gas sample collection bottle, and the carbon dioxide gas collection is completed. Remove the liquid nitrogen and the gas sample collection bottle 25.

[0121] (3) Cluster isotope testing:

[0122] 1) The gas sample collection bottle filled with carbon dioxide gas is connected to the dual-path system process of the gas stable isotope mass spectrometer. The carbon dioxide gas is introduced into the left bellow, and the reference gas is introduced into the right bellow. Specifically, the entire dual-path system is evacuated, first with the foreline pump, and then switched to the molecular pump for 3 minutes. The sample carbon dioxide gas is transferred to the left bellow of the dual-path system of the mass spectrometer, and the right bellow is introduced with a reference gas of substantially the same amount as the left bellow, and the gas pressure on both sides is adjusted to balance.

[0123] 2) Edit the analysis test program to conduct cluster isotope (Δ47) testing, specifically including: edit the sequence test program, select 8 acquisitions test units, each acquisition consists of 14 cycles, start the program for analysis testing, and record high voltage and magnetic field data at the same time. The test time is about 3 hours.

[0124] 3) Cluster isotope (Δ47) data correction processing specifically includes:

[0125] The raw test data was imported into the eastope special software for cluster isotope (Δ47) data processing, the Δ47-raw value of carbon dioxide gas was calculated, and then linear correction and acid fractionation coefficient correction (fractionation coefficient was 0.092‰) were performed to obtain the Δ47 value of the cluster isotope of the calcite standard sample ETH-4.

[0126] The improved device was used to test the 1000℃ heated gas cluster isotope Δ47=0.022±0.016‰ (n=8, ±1S.D. accepted value Δ47=0.025±0.018‰), and the improved device was used to test the calcite standard ETH-4 cluster isotope Δ47=0.574±0.018‰ (n=8, ±1S.D. accepted value Δ47=0.565±0.014‰).

[0127] Multiple tests

[0128] The conditions remain unchanged, and the isotope of the gas cluster heated at 1000℃ is tested, Δ47=0.022±0.016‰ (n=8, ±1S.D. accepted value Δ47=0.025±0.018‰).

[0129] The conditions remained unchanged, and the ETH-4 cluster isotope of the calcite standard sample was tested, and Δ47=0.574±0.018‰ (n=8, ±1S.D. accepted value Δ47=0.565±0.014‰).

[0130] Comparative Example 1

[0131] The device before improvement (oil pump system, without balancing gas unit and rapid cooling device, the same below) tested the isotope of 1000℃ heated gas cluster, Δ47=0.042±0.036‰ (n=8, ±1S.D. accepted value Δ47=0.025±0.018‰).

[0132] Comparative Example 2

[0133] The device before improvement (oil pump system, without balance gas unit and rapid cooling device) tested the calcite standard ETH-4 cluster isotope Δ47=0.592±0.03‰ (n=8, ±1S.D. accepted value Δ47=0.565±0.014‰).

[0134] It can be seen that the accuracy of cluster isotopes measured by the improved carbonate pretreatment device and method is significantly improved, from ±0.036‰~±0.03‰ (n=8, ±1S.D.) before the improvement to ±0.018‰~±0.016‰ (n=8, ±1S.D.), and because the closed reaction end unit has 5 interfaces, the test efficiency is significantly improved.

[0135] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A carbonate cluster isotope test pretreatment device, characterized in that: include: An acidolysis reaction unit, a gas purification unit, and a gas collection unit connected in sequence through pipelines; and a balancing gas unit; The acidolysis unit comprises a closed acidolysis reactor and a common acid bath acidolysis reactor; the closed acidolysis reactor and the common acid bath acidolysis reactor are connected in parallel; and a first vacuum pumping device with a control valve, connected to the acid hydrolysis unit or the balancing gas unit; and a second low vacuum pumping device with a control valve, the second low vacuum pumping device being connected to the first high vacuum pumping device and connected to the gas purification unit; The pipeline is provided with a first high vacuum pipeline, and the first high vacuum pipeline includes a third low vacuum pumping device and a second high vacuum pumping device; The first high vacuum pipeline is connected to the acid hydrolysis unit or the balance gas unit; The first low-vacuum pumping device, the second low-vacuum pumping device and the third low-vacuum pumping device are oil-free systems.

2. The carbonate cluster isotope test pretreatment device according to claim 1, characterized in that: The number of reaction interfaces of the closed acidolysis reactor is more than one, and the reaction interfaces are connected in parallel.

3. The carbonate cluster isotope test pretreatment device according to claim 1, characterized in that: The pumping speed of the first low vacuum device is 8 to 11.4 m / s 3 / h, rated speed is 1500~1800rpm, power is 600~660W; Preferably, the pumping speeds of the second vacuum pumping device and the third vacuum pumping device are independently 0.8 to 1.0 m / s. 3 / h, rated speed is 1600~1800rpm, power is 21~24W.

4. The carbonate cluster isotope test pretreatment device according to claim 1, characterized in that: The rotation speeds of the first high vacuum pumping device and the second high vacuum pumping device are independently 85000-90000, and the pumping speeds are 66-71 L / s.

5. A carbonate cluster isotope testing method, characterized in that: The testing method uses the carbonate cluster isotope testing pretreatment device according to any one of claims 1 to 4 for pretreatment.

6. The testing method according to claim 5, characterized in that: The following steps are involved: Instrument calibration; The equilibrated CO2 gases at 1000°C, 50°C and 25°C are respectively subjected to a first purification process and a first collection process, and then carbonate cluster isotope testing is performed to calibrate the instrument; Carbonate mineral testing; Carrying out a closed acidolysis reaction or a common acid bath acidolysis reaction with a carbonate mineral and phosphoric acid to obtain a reaction product, the reaction product undergoing a second purification treatment and a second collection treatment, and then conducting a carbonate cluster isotope test; Preferably, the temperature of the closed acid hydrolysis reaction is 25 to 90°C; Preferably, the temperature of the common acid bath acidolysis reaction is 25-90°C.

7. The testing method according to claim 6, characterized in that: The test method also includes: Before the first purification treatment, the equilibrated CO2 gas at 1000°C is rapidly cooled; preferably, the equilibrated CO2 gas at 1000°C is cooled to 5-30°C within 30 seconds.

8. The testing method according to claim 7, characterized in that: Before the rapid cooling treatment, the equilibrated CO2 gas at 1000°C is kept at 1000°C for more than 2 hours.

9. The testing method according to claim 5, characterized in that: The test was performed using a dual-path process using a gas stable isotope mass spectrometer.

10. The testing method according to claim 9, characterized in that: The testing method also includes: Edit the sequence test program, select 6 to 8 acquisitions test units, each of which includes 12 to 16 test cycles; preferably, each test lasts 2.5 to 3 hours.

11. The testing method according to claim 5, characterized in that: The testing method further includes: data correction processing; Preferably, the data correction process includes linear correction and acid fractionation coefficient correction to obtain the final Δ 47 value.

Images