A high temperature and high pressure closed system gas washing fractional distillation analysis device and method

Abstract

The application relates to the technical field of oil and gas exploration, in particular to a gas washing fractionation analysis device and method under a high-temperature and high-pressure closed system. The device comprises a gas washing reaction device, a natural gas online collection device, an isotope mass spectrometer, an online trace rapid sampling device of crude oil, a crude oil collection device, a carbon dioxide purification device, a valve, a heating jacket and a liquid nitrogen cold trap. The device realizes real-time detection of carbon isotopes of crude oil and gas in a gas washing fractionation process under a high-temperature and high-pressure state, and has the advantages of fast analysis speed and high accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil and gas exploration, and particularly relates to a gas washing fractionation analysis device and method under a high-temperature and high-pressure closed system. BACKGROUND

[0002] Oil and gas exploration in some areas of China has reached a high exploration degree stage, and deep oil and gas exploration is gradually gaining attention. In the exploration of deep oil and gas, the source rock is generally highly evolved, reaching the stage of generating natural gas. During the migration of the generated natural gas, it passes through the oil reservoir, dissolves and carries away part of the oil components in the oil reservoir, which is called gas washing. Gas washing changes the composition of oil and natural gas and also changes the characteristics of oil and natural gas.

[0003] Identifying the characteristics of oil and gas and determining the source of oil and gas are of great guiding significance for deep oil and gas exploration. Carbon isotope technology of natural gas and oil is an important means for identifying the source of deep oil and gas. However, the gas washing process will form carbon isotope fractionation of oil and natural gas, changing the carbon isotope values of the original oil reservoir oil and natural gas. Therefore, studying the change process of carbon isotopes of oil and natural gas during the whole gas washing process is an important means for oil and gas source comparison in the gas washing process.

[0004] Su Aiguo et al. carried out related work in "Influence of phase control and gas washing fractionation on oil and gas components and carbon isotope composition" (Su Aiguo, Zhang Shuichang, Xiang Longbin, et al. Influence of phase control and gas washing fractionation on oil and gas components and carbon isotope composition [J]. Geochimica, 2000, 29(6): 7.). In the above process, the collected samples are the original and final state oil under normal pressure, while the oil in the underground oil reservoir is in a superpressure state. This method lacks an effective method for testing the isotopes of the oil under the above superpressure state. At the same time, the collection process of the above gas is a process of changing pressure, and during the pressure change process, the gas isotopes produce fractionation effect. The above method lacks an effective means for tracking the gas washing fractionation process.

[0005] There is a need for a device and method for gas washing fractionation analysis under a high-temperature and high-pressure closed system. SUMMARY

[0006] The main purpose of the present application is to provide a gas washing fractionation analysis device and method under a high-temperature and high-pressure closed system. The device realizes real-time detection of carbon isotopes of oil and gas during the gas washing fractionation process under high temperature and high pressure, and has fast analysis speed and high accuracy.

[0007] To achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0008] The application provides a gas washing fractionation analysis device under a high-temperature and high-pressure closed system, which comprises a gas washing reaction device, an online natural gas collection device, an isotope mass spectrometer, an online crude oil micro-quantity rapid sampling device, a crude oil collection device, a carbon dioxide purification device, valves, a heating jacket and liquid nitrogen cold traps; the gas washing reaction device is connected with the online natural gas collection device and the online crude oil micro-quantity rapid sampling device respectively, and the gas washing reaction device is connected with a natural gas source through a valve; the online crude oil micro-quantity rapid sampling device is sequentially connected with the crude oil collection device, the carbon dioxide purification device and a first isotope mass spectrometer; the online natural gas collection device is connected with a carrier gas source through a valve, and a second isotope mass spectrometer is connected with the online natural gas collection device; the crude oil collection device is connected with an oxygen source through a valve, the crude oil collection device is placed in a first liquid nitrogen cold trap, and the heating jacket surrounds the first liquid nitrogen cold trap; and the online crude oil micro-quantity rapid sampling device is placed in a second liquid nitrogen cold trap.

[0009] The online natural gas collection device is arranged, and real-time tracking of carbon isotopes of natural gas can be realized. The online crude oil micro-quantity rapid sampling device can prevent fractionation of carbon isotopes of crude oil in a transmission process.

[0010] The online crude oil micro-quantity rapid sampling device and the crude oil collection device are respectively placed in liquid nitrogen cold traps, so that the transfer of crude oil samples under low-temperature conditions is realized, the escape of dissolved hydrocarbon gas is prevented, and the accuracy of data analysis is ensured. The online natural gas collection device is connected with the carrier gas source, so that the complete collection of natural gas in sample analysis is ensured, and the interference of the fractionation effect of carbon isotopes of natural gas on data is eliminated.

[0011] Further, the gas washing reaction device is also connected with a pressure gauge and a temperature control system. The sample under different temperature and pressure conditions in the gas washing reaction device can be selected.

[0012] Further, a valve is arranged on a pipeline between the gas washing reaction device and the crude oil collection device.

[0013] Further, a valve is arranged on a pipeline between the online natural gas collection device and the second isotope mass spectrometer.

[0014] Further, valves are respectively arranged on a pipeline between the crude oil collection device and the carbon dioxide purification device and on a pipeline between the carbon dioxide purification device and the first isotope mass spectrometer.

[0015] The application also provides a gas washing fractionation analysis method under a high-temperature and high-pressure closed system, which is analyzed by using the gas washing fractionation analysis device under the high-temperature and high-pressure closed system and comprises the following steps.

[0016] The crude oil is added into the gas washing reaction device, the gas washing reaction device is heated to the required temperature of the experiment, natural gas is introduced, the pressure in the gas washing reaction device is increased to the required pressure of the experiment and reaches a stable state, then the introduction of natural gas is stopped, and carbon isotope analysis of the natural gas and the crude oil is carried out;

[0017] The step of analyzing the carbon isotope of the natural gas comprises the following steps that: the natural gas in the gas washing reaction device is collected by the online natural gas collecting device, and the carrier gas is injected into the online natural gas collecting device; the natural gas and the carrier gas enter the second isotope mass spectrometer, and the online analysis of the carbon isotope of the natural gas is carried out.

[0018] The step of analyzing the carbon isotope of the crude oil comprises the following steps that: the liquid nitrogen cold trap is opened, and the temperature of the trace fast sampling device of the crude oil and the crude oil collecting device is ensured to not cause the loss of the dissolved natural gas; the trace crude oil is taken by the trace fast sampling device of the crude oil, and after the trace crude oil is completely transferred into the crude oil collecting device; the liquid nitrogen cold trap is closed, the electric heating jacket is opened to heat the crude oil collecting device, oxygen is introduced into the crude oil collecting device, the organic matter in the crude oil is completely combusted, the carbon dioxide generated by the combustion is purified, and the purified carbon dioxide is subjected to carbon isotope analysis.

[0019] Further, the carrier gas used in the step of analyzing the carbon isotope of the natural gas is helium.

[0020] Further, in the step of analyzing the carbon isotope of the crude oil, the crude oil collecting device is heated to 850-1000 DEG C.

[0021] Further, the pressure in the gas washing reaction device is increased to the required pressure of the experiment, and the stable state is that the required pressure of the experiment is maintained constant for at least 15 min.

[0022] Compared with the prior art, the present application has the following advantages:

[0023] The device realizes real-time detection of the carbon isotope of the crude oil and the gas in the gas washing fractionation process under high temperature and high pressure, and has the advantages of fast analysis speed and high accuracy of the obtained results. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Fig. 1 is a structural schematic diagram of the gas washing fractionation analysis device under a high temperature and high pressure closed system according to Embodiment 1 of the present application.

[0025] The components include: 1. Gas washing reaction device; 2. Temperature control system; 3. Pressure gauge; 4. Crude oil micro-rapid sampling device; 5. Crude oil collection device; 6. Carbon dioxide purification device; 7. First isotope mass spectrometer; 8. Natural gas online collection device; 9. Second isotope mass spectrometer; 10. Carrier gas source; 11. Oxygen source; 12. Natural gas source; 13. Valve 1; 14. Valve 2; 15. Valve 3; 16. Valve 4; 17. Valve 5; 18. Valve 6; 19. Valve 7; 20. First liquid nitrogen cold trap; 21. Second liquid nitrogen cold trap; 22. Heating jacket. Detailed Implementation

[0026] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0027] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0029] Example 1

[0030] like Figure 1 As shown, the gas washing fractionation analysis device under the high temperature and high pressure closed system includes a gas washing reaction device 1, a natural gas online collection device 8, an isotope mass spectrometer, a crude oil micro-rapid sampling device 4, a crude oil collection device 5, a carbon dioxide purification device 6, valves, a heating jacket 22, and a liquid nitrogen cold trap.

[0031] Gas washing reaction device 1 is connected to natural gas online collection device 8 and crude oil micro-rapid sampling device 4 respectively. Gas washing reaction device 1 is connected to natural gas source 12 through valve 13. Valve 2 14 is installed on the pipeline connecting gas washing reaction device 1 and natural gas online collection device 8. Gas washing reaction device is also connected to pressure gauge 3 and temperature control system 2 respectively. Crude oil micro-rapid sampling device 4 is connected to crude oil collection device 5, carbon dioxide purification device 6 and first isotope mass spectrometer 7 in sequence. Valve 5 17 is installed on the pipeline connecting crude oil collection device 5 and carbon dioxide purification device 6. Valve 6 18 is installed on the pipeline connecting carbon dioxide purification device 6 and first isotope mass spectrometer 7. Crude oil collection device 5 is connected to oxygen source 11 through valve 7 19. Crude oil collection device 5 is placed in first liquid nitrogen cold trap 20. Heating jacket 22 surrounds first liquid nitrogen cold trap 20. Crude oil micro-rapid sampling device 4 is placed in second liquid nitrogen cold trap 21.

[0032] The online natural gas collection device 8 is connected to the carrier gas source 10 via valve 16; the second isotope mass spectrometer 9 is connected to the online natural gas collection device 8, and valve 15 is installed on the connecting pipeline.

[0033] Example 2

[0034] A gas washing fractionation analysis method under a high-temperature, high-pressure closed system includes the following steps: analysis is performed using the gas washing fractionation analysis apparatus under a high-temperature, high-pressure closed system described in Example 1:

[0035] 1. Carbon isotope analysis method for natural gas

[0036] (1) Add crude oil to gas washing reaction unit 1;

[0037] (2) Heat the gas washing reaction apparatus 1 to the specified temperature according to the experimental requirements;

[0038] (3) Close valve 13 to allow natural gas to enter gas washing reactor 1 and observe the reading of pressure gauge 3 in gas washing reactor 1; when the system pressure begins to increase, it indicates that the crude oil in the system has reached saturation.

[0039] (4) Continue to supply natural gas. When the system pressure rises to the specified experimental pressure, disconnect valve 13 and observe the system pressure. When the system pressure remains constant at the specified pressure for 20 minutes, it indicates that the gas washing device 1 has reached a steady state. If the system pressure drops, open valve 13 and replenish natural gas to the specified pressure.

[0040] (5) Disconnect valve 3 15 and valve 4 16, and close valve 2 14 to allow the natural gas in the gas washing reaction device 1 to diffuse to the natural gas online collection device 8;

[0041] (6) open valve two 14, close valve four 16, inject carrier gas into the natural gas online collection device 8, and the carrier gas used is helium;

[0042] (7) close valve three 15, natural gas and carrier gas enter the second isotope mass spectrometer 9, and online analysis of carbon isotopes of natural gas can be realized.

[0043] 2. Crude oil carbon isotope analysis method:

[0044] (1) add crude oil in the gas washing reaction device 1;

[0045] (2) according to the experimental requirements, heat the gas washing reaction device 1 to the specified temperature;

[0046] (3) close valve one 13, make natural gas gas enter the gas washing reaction device 1, and observe the pressure gauge 3 of the gas washing reaction device 1; when the system pressure begins to increase, it indicates that the crude oil in the system has reached saturation state;

[0047] (4) continue to inject natural gas, when the system pressure rises to the specified pressure, open valve one 13, and supplement natural gas to the specified pressure;

[0048] (5) open liquid nitrogen cold trap 20 and liquid nitrogen cold trap 21, and ensure that the temperature of the trace rapid sampling device 4 and the crude oil collection device 5 will not cause the loss of dissolved natural gas;

[0049] (6) open the trace rapid sampling device 4, take trace crude oil, and transfer it to the crude oil collection device 5, because the internal temperature is very low, it can ensure that the dissolved natural gas is not lost;

[0050] (7) open the heating jacket 22, heat the crude oil collection device 5 to 900 DEG C, close valve seven 19, and inject oxygen 15 into the crude oil collection device 5; make the organic matter in the crude oil completely burn;

[0051] (8) open valve seven 19, close valve five 17, and make the reaction generated carbon dioxide and other gases enter the carbon dioxide purification device 6;

[0052] (9) close valve six 18, and the purified carbon dioxide gas prepared by the first isotope mass spectrometer 7 is detected, and the carbon isotope value in the carbon dioxide gas in the crude oil can be obtained, that is, the carbon isotope value of the crude oil.

[0053] The above embodiments are the preferred embodiments of the present application, but the embodiments of the present application are not limited to the above embodiments, and any changes, modifications, substitutions, combinations, simplifications, etc. made without departing from the spirit and principles of the present application should be equivalent replacement manners and should be included in the protection scope of the present application.

Claims

1. A gas washing fractionation analysis apparatus for a high-temperature, high-pressure closed system, characterized in that, Includes a gas washing reaction device, an online natural gas collection device, an isotope mass spectrometer, an online crude oil micro-rapid sampling device, a crude oil collection device, a carbon dioxide purification device, valves, a heating jacket, and a liquid nitrogen cold trap; The gas washing reactor is connected to the online natural gas collection device and the online crude oil micro-rapid sampling device, respectively. The gas washing reactor is connected to the natural gas source through a valve. The online crude oil micro-rapid sampling device is connected in sequence to the crude oil collection device, the carbon dioxide purification device, and the first isotope mass spectrometer. The online natural gas collection device is connected to the carrier gas source through a valve, and the second isotope mass spectrometer is connected to the online natural gas collection device. The crude oil collection device is connected to the oxygen source through a valve and is placed inside the first liquid nitrogen cold trap, which is surrounded by a heating jacket. The online crude oil micro-rapid sampling device is placed inside the second liquid nitrogen cold trap.

2. The gas washing and fractionation analysis apparatus under a high-temperature and high-pressure closed system according to claim 1, characterized in that, The gas washing reactor is also connected to a pressure gauge and a temperature control system.

3. The gas washing and fractionation analysis apparatus under a high-temperature and high-pressure closed system according to claim 1, characterized in that, Valves are installed on the pipeline between the gas washing reaction unit and the crude oil collection unit.

4. The gas washing and fractionation analysis apparatus under a high-temperature and high-pressure closed system according to claim 1, characterized in that, A valve is installed on the pipeline connecting the online natural gas collection device and the second isotope mass spectrometer.

5. The gas washing and fractionation analysis apparatus under a high-temperature and high-pressure closed system according to claim 1, characterized in that, Valves are installed on the pipeline connecting the crude oil collection unit and the carbon dioxide purification unit, and on the pipeline connecting the carbon dioxide purification unit and the first isotope mass spectrometer.

6. A gas washing fractionation analysis method under a high-temperature, high-pressure closed system, characterized in that, The gas washing fractionation analysis apparatus under a high-temperature and high-pressure closed system as described in any one of claims 1-5 includes the following steps: Crude oil was added to the gas washing reactor, and the reactor was heated to the required experimental temperature. Natural gas was introduced, and after the pressure in the gas washing reactor rose to the required experimental pressure and reached a stable state, the natural gas supply was stopped, and carbon isotope analysis was performed on the natural gas and crude oil. The steps of natural gas carbon isotope analysis include: collecting natural gas from the gas washing reaction device using an online natural gas collection device, injecting carrier gas into the online natural gas collection device, and then the natural gas and carrier gas entering a second isotope mass spectrometer for online analysis of natural gas carbon isotopes. The steps for carbon isotope analysis in crude oil include: opening the liquid nitrogen cold trap to ensure that the temperature of the crude oil micro-rapid sampling device and the crude oil collection device will not cause the loss of dissolved natural gas; taking a micro-amount of crude oil through the crude oil micro-rapid sampling device and waiting for it to be completely transferred to the crude oil collection device; closing the liquid nitrogen cold trap, turning on the electric heating mantle to heat the crude oil collection device, introducing oxygen into the crude oil collection device, completely burning the organic matter in the crude oil, purifying the carbon dioxide generated by combustion, and performing carbon isotope analysis on the purified carbon dioxide.

7. The method according to claim 6, characterized in that, Helium is used as the carrier gas in the carbon isotope analysis of natural gas.

8. The method according to claim 6, characterized in that, In the carbon isotope analysis step of crude oil, the crude oil collection device is heated to 850-1000℃.

9. The method according to claim 6, characterized in that, The pressure in the gas washing reaction apparatus is increased to the pressure required for the experiment, and the stable state is reached after maintaining the pressure required for the experiment constant for at least 15 minutes.

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