Sampling device for geological storage of CO2 and operation method of sampling device

Abstract

The invention provides a sampling device for geological storage of CO2 and an operation method thereof.The sampling device is installed in a casing pipe in a well and comprises a first packer, a second packer, a second packer and a third packer, the second packer and the first packer are arranged in a spaced mode in the vertical direction, and a sampling space is defined by the second packer, the first packer and the casing pipe; the pushing pipe is arranged on the first packer in a penetrating manner and is communicated with the sampling space; the sampling pipe is arranged on the first packer and the second packer in a penetrating mode, the first end of the sampling pipe extends into the sampling space from the second packer, the second end of the sampling pipe penetrates through the second packer from bottom to top, and a liquid inlet hole communicated with the sampling space and the lower portion of the second packer is formed in the sampling pipe. According to the technical scheme, the problems that in the prior art, the sampling capacity is too small, and the detection and analysis requirements of a large number of sampled samples cannot be met are effectively solved.

Description

Technical Field

[0001] The present invention relates to the field of geological storage of carbon dioxide, and in particular to a sampling device for geological storage of CO2 of underground fluid in a carbon dioxide geological storage engineering application and an operating method thereof. Background Art

[0002] Deep well sampling is a commonly used method for deep underground formation fluids. By collecting groundwater and other fluid samples, it can provide important data support for groundwater resource exploration, geological environment investigation, etc. However, the existing deep well sampling devices have some limitations.

[0003] The deep well sampling device needs to be lowered from the wellhead to the bottom of the well for sampling. Therefore, its structure needs to consider the size and weight limit of the device. Therefore, the size, volume and weight of this device are usually small, which limits the sampling capacity. Therefore, the existing deep well sampling device sends the sampled samples to the ground for analysis through a pipeline, but the sampling capacity is too small to meet the detection and analysis research needs of a large number of sampled samples. Summary of the invention

[0004] The main purpose of the present invention is to provide a sampling device for CO2 geological storage and an operating method thereof, so as to solve the problem in the prior art that the sampling capacity is too small to meet the detection and analysis requirements of a large number of sampled samples.

[0005] In order to achieve the above-mentioned purpose, according to one aspect of the present invention, there is provided a sampling device for geological storage of CO2, which is installed in the casing in the well, and the sampling device comprises: a first packer; a second packer, which is spaced apart from the first packer in the vertical direction, and a sampling space is enclosed between the second packer, the first packer and the casing; a push pipe, which is passed through the first packer and connected with the sampling space; a sampling tube, which is passed through the first packer and the second packer, the first end of the sampling tube extends from the second packer into the sampling space, the second end of the sampling tube passes through the second packer from bottom to top, and the sampling tube is provided with a liquid inlet hole which connects the sampling space and the bottom of the second packer.

[0006] Furthermore, the sampling device also includes a sampling tube connected to the liquid inlet hole, the sampling tube is located below the second sealer, and a one-way valve is provided on the sampling tube. The one-way valve allows the sampling sample in the casing to enter the liquid inlet hole from below the sampling tube.

[0007] Furthermore, the sampling tube includes a first pipe section and a second pipe section arranged at intervals in the horizontal direction, and the sampling tube also includes an intermediate pipe section connected between the first pipe section and the second pipe section. The first pipe section extends into the sampling space from the second seal, the second pipe section passes through the first seal and the second seal, and the liquid inlet is arranged on the intermediate pipe section.

[0008] Furthermore, the first pipe section and the second pipe section are arranged in parallel or inclined.

[0009] Furthermore, when the first pipe segment and the second pipe segment are arranged in parallel, there is a first distance between the lower end of the first pipe segment and the second packer, and there is a second distance between the lower end of the second pipe segment and the second packer, and the second distance is less than or equal to the first distance.

[0010] Furthermore, the middle pipe section is U-shaped or spiral-shaped.

[0011] Furthermore, a pressure sensor is provided on the second packer, and the pressure sensor is used to detect the pressure in the sampling space. The sampling device also includes a controller connected to the pressure sensor.

[0012] Furthermore, a flow sensor is provided on the sampling tube, and the flow sensor is used to detect the flow of the sampling sample in the sampling tube, and the flow sensor is connected to the controller.

[0013] Furthermore, a temperature sensor is provided on the first packer, and the temperature sensor is used to detect the temperature in the sampling space, and the temperature sensor is connected to the controller.

[0014] According to another aspect of the present invention, there is provided an operating method of a sampling device, which is operated using the above-mentioned sampling device. The operating method of the sampling device comprises the following steps: placing the sampling device into deep underground formation fluid, allowing part of the deep underground formation fluid to enter the sampling space of the sampling device to form a sampling sample to be detected and analyzed; using inert gas nitrogen or argon to push the sampling sample in the sampling space into the sampling tube of the sampling device, and then pushing it to the ground through the sampling tube; or, using negative pressure to suck the sampling sample in the sampling space into the sampling tube of the sampling device, and then sucking it back to the ground through the sampling tube.

[0015] By applying the technical solution of the present invention, the sampling device for CO2 geological storage is installed in the casing in the well. The sampling device includes: a first packer, a second packer, a push pipe and a sampling pipe. The second packer and the first packer are arranged at intervals in the vertical direction, and a sampling space is surrounded by the second packer, the first packer and the casing. The push pipe is arranged on the first packer and communicated with the sampling space. The sampling pipe is arranged on the first packer and the second packer, the first end of the sampling pipe extends into the sampling space from the second packer, the second end of the sampling pipe passes through the second packer from bottom to top, and a liquid inlet hole connecting the sampling space and the lower part of the second packer is provided on the sampling pipe. In this way, the deep formation fluid in the underground flows through the first end of the sampling pipe through the liquid inlet hole and enters the sampling space to form a sample to be detected and analyzed. The sampling device of the present application makes full use of the structure of the casing to form a larger sampling space for storing a large amount of sampled samples to meet the subsequent detection and analysis requirements. During sampling, the push tube uses inert gas to push the sample in the sampling space through the sampling tube, and the second end of the sampling tube is pushed to the ground for analysis, or when negative pressure sampling is used, the sample passes through the sampling tube, and is sucked back to the ground from the first end of the sampling tube to the second end of the sampling tube for analysis. Therefore, the technical solution of the present application effectively solves the problem in the prior art that the sampling capacity is too small and cannot meet the detection and analysis needs of a large number of sample samples. Among them, the sampling space enclosed by the second packer, the first packer and the casing can ensure that no pollutants or fluids from external non-target layers will enter the sampling space during the sampling process. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0017] Figure 1 A perspective schematic diagram showing an embodiment of a sampling device for geological storage of CO2 according to the present invention installed in a casing in a well.

[0018] The above drawings include the following reference numerals:

[0019] 10. Casing;

[0020] 11. First packer;

[0021] 12. Second packer; 13. Sampling space;

[0022] 21. Push tube;

[0023] 22, sampling tube; 221, first tube section; 222, second tube section; 223, middle tube section; 23, liquid inlet;

[0024] 31. Sample injection tube; 32. One-way valve. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0026] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0027] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0028] like Figure 1As shown, the present application provides a sampling device for CO2 geological storage, and an embodiment of the sampling device is installed in a casing 10 in a well. The sampling device includes: a first packer 11, a second packer 12, a push pipe 21 and a sampling pipe 22. The second packer 12 and the first packer 11 are arranged at intervals in the vertical direction, and a sampling space 13 is enclosed between the second packer 12, the first packer 11 and the casing 10. The push pipe 21 is penetrated on the first packer 11 and communicated with the sampling space 13. The sampling pipe 22 is penetrated on the first packer 11 and the second packer 12, the first end of the sampling pipe 22 extends from the second packer 12 into the sampling space 13, the second end of the sampling pipe 22 passes through the second packer 12 from bottom to top, and the sampling pipe 22 is provided with a liquid inlet 23 connecting the sampling space 13 and the lower part of the second packer 12. The sampling space 13 formed between the second packer 12, the first packer 11 and the casing 10 can ensure that no pollutants or fluids from external non-target layers will enter the sampling space 13 during the sampling process. The first packer 11 and the second packer 12 play a sealing role. At the same time, the sampling space 13 sealed by the first packer 11 and the second packer 12 is used to store sampled samples, which can greatly increase the sampling volume. It should be noted that the casing 10 in the well refers to the casing 10 in the vertical well.

[0029] By applying the technical solution of this embodiment, the underground deep formation fluid flows through the first end of the sampling tube 22 through the liquid inlet hole 23 and enters the sampling space 13 to form a sample to be detected and analyzed. The sampling device of this application makes full use of the structure of the casing 10 to form a larger sampling space 13 for storing a large number of sampled samples to meet the subsequent detection and analysis requirements. During sampling, the push tube 21 pushes the sampled sample in the sampling space 13 through the sampling tube 22 through an inert gas (nitrogen or argon) and pushes it to the ground from the second end of the sampling tube 22 for analysis, or when negative pressure sampling is used, the sampled sample passes through the sampling tube 22 and is sucked back to the ground from the first end of the sampling tube 22 to the second end of the sampling tube 22 for analysis. Therefore, the technical solution of this embodiment effectively solves the problem in the prior art that the sampling capacity is too small and cannot meet the detection and analysis requirements of a large number of sampled samples.

[0030] It should be noted that the deep underground formation fluid of the present application can be gas or liquid. When the deep underground formation fluid is gas, the sampling sample of the gas in the sampling space 13 can be drawn to the ground through the sampling tube 22 by means of inert gas or negative pressure, so as to facilitate subsequent analysis. When the deep underground formation fluid is liquid, the sampling sample of the liquid in the sampling space 13 can be drawn to the ground through the sampling tube 22 by means of inert gas, so as to facilitate subsequent analysis.

[0031] The implementation effect of this sampling device is remarkable. It can not only accurately collect fluid samples from the carbon dioxide storage layer, but also effectively avoid direct contact between the sample and the well wall or casing, reducing the possibility of sample contamination. In terms of application scenarios, it is widely used in monitoring various geological conditions, including but not limited to environmental comparison studies before and after storage, storage layer stability assessment, carbon dioxide leakage detection, etc., providing researchers with an accurate and reliable source of samples, further supporting the optimization and development of carbon dioxide geological storage technology.

[0032] like Figure 1 As shown, the sampling device also includes a sampling tube 31 connected to the liquid inlet 23. The sampling tube 31 is located below the second packer 12. A one-way valve 32 is provided on the sampling tube 31. The one-way valve 32 allows the sample in the casing 10 to enter the liquid inlet 23 from below the sampling tube 31. The setting of the one-way valve 32 ensures that the sampling process can maintain unidirectionality regardless of how the downhole conditions change. That is, it ensures that the formation fluid can only flow from the deep underground layer to the ground until it flows into the sampling space 13. When sampling with inert gas, the sampled sample passes through the sampling tube 22 and returns to the ground from the first end of the sampling tube 22 to the second end of the sampling tube 22, or when negative pressure sampling is used, the sampled sample passes through the sampling tube 22 and returns to the ground from the first end of the sampling tube 22 to the second end of the sampling tube 22, so as to prevent the sample from flowing back to the formation through the sampling tube 31 and avoid the sample from returning to the ground. The one-way valve 32 is opened and closed by the pressure difference of the formation fluid. When the pressure of the formation fluid is higher than the pressure in the surface pressure sampling tube, the one-way valve opens, allowing the formation fluid to flow from the sampling tube 31 to the sampling tube and then enter the sampling space 13.

[0033] The addition of a one-way valve greatly improves the reliability of the sampling device, which prevents the collected samples from flowing back when the pressure changes, thereby avoiding sample mixing and maintaining the purity of the samples. This design is particularly suitable for long-term monitoring projects, such as continuous tracking of sealing effects and long-term observation of underground fluid dynamics. It not only simplifies the maintenance process, but also improves the consistency and effectiveness of monitoring data, provides more stable data support for researchers and engineers, and reduces the cost and risk of long-term monitoring.

[0034] Specifically, the first packer 11 and the second packer 12 , the push pipe 21 and the sampling pipe 22 are connected together and arrive at the sampling position in the well along with the downhole pipe string.

[0035] The first packer 11 and the second packer 12 of the present embodiment are both downhole packers disclosed in the Chinese patent application with publication number CN113216892A.

[0036] like Figure 1As shown, in order to facilitate the setting of the liquid inlet hole 23, the sampling tube 22 includes a first tube section 221 and a second tube section 222 spaced apart in the horizontal direction, and the sampling tube 22 also includes an intermediate tube section 223 connected between the first tube section 221 and the second tube section 222. The first tube section 221 extends from the second packer 12 into the sampling space 13, the second tube section 222 is passed through the first packer 11 and the second packer 12, and the liquid inlet hole 23 is set on the intermediate tube section 223.

[0037] The segmented design of the sampling tube enables the device to collect samples at different depths, increasing the diversity of samples and improving the comprehensiveness and accuracy of sample analysis. In scientific research applications, this device can help researchers understand the fluid changes, chemical reactions and biological activities in the process of carbon dioxide storage in more detail, which is of great significance for in-depth research on the mechanism of carbon dioxide geological storage and the assessment of storage safety and environmental impact. By analyzing these samples, researchers can more scientifically predict the long-term effects of carbon dioxide storage, providing a solid scientific basis for the formulation of storage strategies and environmental policies.

[0038] The sampling tube and the injection tube 31 in this embodiment are both made of stainless steel, which has the characteristics of pressure resistance and corrosion resistance.

[0039] In this embodiment, a plurality of liquid inlets are provided at the lower end of the sampling tube 22. The liquid inlets are notches provided on the end wall of the lower end of the sampling tube 22. The notches are gourd-shaped. On the one hand, they facilitate the deep underground formation fluid to flow into the straight sampling tube. On the other hand, the gourd-shaped notches can block some impurities in the formation fluid, thereby achieving the purpose of filtering.

[0040] like Figure 1 As shown, the first pipe section 221 and the second pipe section 222 are arranged in parallel. In this way, the depth and position of the sampling space 13 can be better controlled, thereby improving the sampling precision and accuracy.

[0041] The parallel or inclined setting of the pipe section greatly enhances the flexibility and adaptability of the sampling device, enabling it to work effectively in complex geological environments such as inclined wells and horizontal wells, and collect more accurate and comprehensive sample data. This design not only meets the conventional vertical well sampling needs, but also breaks through the limitations of traditional sampling technology in inclined wells and horizontal wells, providing strong technical support for the multi-faceted monitoring of geological storage projects. By sampling at different angles and depths, researchers and engineers can have a more comprehensive understanding of the physical and chemical properties of the carbon dioxide storage layer, as well as the impact of the storage process on the surrounding geological environment, providing a key data basis for the continuous optimization and promotion of carbon dioxide geological storage technology.

[0042] Of course, in other embodiments, the first pipe segment 221 and the second pipe segment 222 are arranged obliquely.

[0043] like Figure 1 As shown, when the first pipe segment 221 and the second pipe segment 222 are arranged in parallel, there is a first distance between the lower end of the first pipe segment 221 and the second packer 12, and there is a second distance between the lower end of the second pipe segment 222 and the second packer 12, and the second distance is less than or equal to the first distance.

[0044] Accurately locating the distance between the first and second pipe sections and the packer is the key to improving sample quality and monitoring efficiency of the sampling device. By controlling the residence time of the sample in the pipeline, physical and chemical changes of the sample due to long-term contact are avoided, ensuring the originality and representativeness of the sample. This precise control is particularly suitable for monitoring projects that require extremely high sample timeliness, such as rapid response carbon dioxide leakage monitoring, immediate response to geological changes, etc., providing researchers with valuable real-time data and improving the accuracy and effectiveness of monitoring work.

[0045] like Figure 1 As shown, in order to reduce the disturbance to the formation fluid during sampling and avoid affecting the accuracy of detection and analysis, the middle pipe section 223 is U-shaped.

[0046] The U-shaped or spiral intermediate pipe section design promotes the mixing and reaction of different fluids by increasing the contact area and time of the fluids in the pipeline, ensuring the uniformity and representativeness of the samples, which is of great significance for in-depth research on the interaction between carbon dioxide and formation water, and evaluating the chemical stability of the storage layer. By analyzing these mixed samples, researchers can more accurately understand the chemical reaction path in the carbon dioxide storage process, provide scientific reference for optimizing storage conditions and predicting storage effects, and further promote the innovation and application of carbon dioxide geological storage technology.

[0047] In other embodiments, the middle tube section 223 is spiral-shaped.

[0048] like Figure 1 As shown, in order to detect the pressure in the sampling space 13, a pressure sensor is provided on the second packer 12, and the pressure sensor is used to detect the pressure in the sampling space 13. The sampling device also includes a controller connected to the pressure sensor.

[0049] The integrated pressure sensor and controller realize the intelligent operation of the sampling device, and can automatically adjust the sampling strategy according to the real-time monitored pressure changes to ensure the collection of high-quality samples under safe conditions. This intelligent design is particularly suitable for monitoring projects with complex geological conditions and rapid environmental changes, such as carbon dioxide storage monitoring under high pressure and high temperature environments, and geological change monitoring in areas with frequent seismic activity. Through automated pressure monitoring and sampling control, not only the safety and efficiency of monitoring are improved, but also the errors of human operation are reduced, providing researchers with more accurate and consistent monitoring data, and promoting the intelligent development of geological monitoring technology.

[0050] like Figure 1 As shown, in order to detect the flow rate in the sampling space 13, a flow sensor is provided on the sampling tube 22. The flow sensor is used to detect the flow rate of the sample in the sampling tube 22. The flow sensor is connected to the controller.

[0051] The addition of the flow sensor enables the sampling device to adjust the sampling rate in real time according to the sample flow conditions, avoiding incomplete or excessive sample collection due to uneven flow rates, and ensuring the representativeness of the sample and the accuracy of monitoring. This design is particularly suitable for monitoring projects that require extremely high sample accuracy, such as precise control of carbon dioxide injection rates, detailed analysis of underground fluid flow patterns, etc. It provides researchers with more accurate sample data, improves the efficiency and quality of monitoring, and provides technical support for the refined management of carbon dioxide geological storage technology.

[0052] like Figure 1 As shown, in order to detect the temperature in the sampling space 13, a temperature sensor is provided on the first packer 11. The temperature sensor is used to detect the temperature in the sampling space 13, and the temperature sensor is connected to the controller.

[0053] The combination of temperature sensor and controller realizes the dynamic monitoring of the thermodynamic environment of the carbon dioxide storage area, and provides key temperature data for storage effect evaluation and geological environment analysis. This design is particularly suitable for monitoring projects that require comprehensive analysis of the geological environment, such as evaluating the thermal stability and thermal effect of the storage layer, monitoring the impact of the storage process on the surrounding geological environment, etc. It provides more comprehensive and in-depth geological information for scientific researchers, helps scientific decision-making and technical optimization, and further improves the safety and environmental benefits of carbon dioxide geological storage.

[0054] like Figure 1As shown, a plurality of guide grooves are arranged on the upper surface of the second packer 12, and the plurality of guide grooves are connected to the first end of the sampling tube 22. The plurality of guide grooves are spirally distributed around the first end of the sampling tube 22. The use of spirally distributed guide grooves can make the sampled sample more uniform in the process of entering the sampling tube, reduce the mixing and contamination in the sampling process, and make it easier for the sampled sample to enter the sampling tube, thereby improving the sampling efficiency. And the width of each guide groove gradually decreases from top to bottom. The gradually decreasing width of each guide groove can increase the stability of the sampling tube, reduce the shaking and vibration in the sampling process, and improve the stability and reliability of the sampling.

[0055] The present application also provides an operating method of a sampling device, which is operated by using the above-mentioned sampling device, and the operating method of the sampling device includes the following steps: placing the sampling device into the deep underground formation fluid, and part of the deep underground formation fluid enters the sampling space 13 of the sampling device to form a sample to be detected and analyzed; using inert gas nitrogen or argon to push the sample in the sampling space 13 into the sampling tube 22 of the sampling device, and then push it to the ground through the sampling tube 22; or, using negative pressure to suck the sample in the sampling space 13 into the sampling tube 22 of the sampling device, and then suck it back to the ground through the sampling tube 22. Since the above-mentioned sampling device can solve the problem in the prior art that the sampling capacity is too small and cannot meet the detection and analysis requirements of a large number of sampled samples, the same technical problem can be solved by using the above-mentioned sampling device and adopting the operating method of the sampling device to operate.

[0056] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the devices or elements referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention. The directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0057] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0058] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A sampling device for geological storage of CO2, installed in a casing (10) in a well, characterized in that: The sampling device comprises: a first packer (11); A second packer (12) is arranged spaced apart from the first packer (11) in a vertical direction, and a sampling space (13) is enclosed between the second packer (12), the first packer (11) and the casing (10); A push pipe (21) is passed through the first packer (11) and communicated with the sampling space (13); A sampling tube (22), wherein the sampling tube (22) is passed through the first packer (11) and the second packer (12), wherein the first end of the sampling tube (22) extends from the second packer (12) into the sampling space (13), and the second end of the sampling tube (22) passes through the second packer (12) from bottom to top, and the sampling tube (22) is provided with a liquid inlet hole (23) connecting the sampling space (13) and the bottom of the second packer (12).

2. The sampling device according to claim 1, characterized in that: The sampling device also includes a sampling tube (31) connected to the liquid inlet hole (23), the sampling tube (31) is located below the second packer (12), and a one-way valve (32) is provided on the sampling tube (31), and the one-way valve (32) allows the sample in the casing (10) to enter the liquid inlet hole (23) from below the sampling tube (31).

3. The sampling device according to claim 2, characterized in that: The sampling tube (22) comprises a first tube section (221) and a second tube section (222) which are arranged at intervals in the horizontal direction. The sampling tube (22) further comprises an intermediate tube section (223) connected between the first tube section (221) and the second tube section (222). The first tube section (221) extends from the second packer (12) into the sampling space (13). The second tube section (222) is passed through the first packer (11) and the second packer (12). The liquid inlet hole (23) is arranged on the intermediate tube section (223).

4. The sampling device according to claim 3, characterized in that: The first pipe section (221) and the second pipe section (222) are arranged in parallel or inclined.

5. The sampling device according to claim 4, characterized in that: When the first pipe segment (221) and the second pipe segment (222) are arranged in parallel, there is a first distance between the lower end of the first pipe segment (221) and the second packer (12), and there is a second distance between the lower end of the second pipe segment (222) and the second packer (12), and the second distance is less than or equal to the first distance.

6. The sampling device according to claim 3, characterized in that: The middle pipe section (223) is U-shaped or spiral-shaped.

7. The sampling device according to claim 1, characterized in that: The second packer (12) is provided with a pressure sensor, which is used to detect the pressure in the sampling space (13). The sampling device also includes a controller connected to the pressure sensor.

8. The sampling device according to claim 7, characterized in that: The sampling tube (22) is provided with a flow sensor, the flow sensor is used to detect the flow of the sample in the sampling tube (22), and the flow sensor is connected to the controller.

9. The sampling device according to claim 7, characterized in that: The first packer (11) is provided with a temperature sensor, the temperature sensor is used to detect the temperature in the sampling space (13), and the temperature sensor is connected to the controller.

10. A method for operating a sampling device, characterized in that: The sampling device according to any one of claims 1 to 9 is used for operation, and the operation method of the sampling device comprises the following steps: Putting the sampling device into the deep underground formation fluid, so that part of the deep underground formation fluid enters the sampling space (13) of the sampling device to form a sample to be detected and analyzed; Using inert gas nitrogen or argon to push the sample in the sampling space (13) into the sampling tube (22) of the sampling device, and then pushing the sample to the ground through the sampling tube (22); or, The sample in the sampling space (13) is sucked into the sampling tube (22) of the sampling device by using negative pressure, and then sucked back to the ground through the sampling tube (22).

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