Downhole liquid level fluid sampler

Abstract

The invention discloses an underground liquid level fluid sampler, and relates to the technical field of fluid sampling devices. The sampler comprises a power assembly, a control assembly and a sampling assembly. The power assembly comprises an upper connector, a power bin outer cylinder, an elastic piece, a driving piece and a battery unit. The control assembly comprises a control bin outer cylinder, the sampling assembly comprises a sample placing valve and a sampling cavity, one end of the control bin outer cylinder is connected with the elastic piece through the connecting assembly, the control bin outer cylinder is connected with the sampling cavity through the connecting assembly, and the sampling cavity is connected with the sample placing valve; when entering a well, power is provided for the sampler through the driving part and the battery unit, the power is transmitted to the elastic part, the elastic force of the elastic part pushes the control bin outer cylinder and the sampling cavity to move downwards, the sampling cavity is closed, and then liquid level closed fluid is obtained. The sampler enters the position below the liquid level, fluid enters the sampling cavity through the liquid inlet hole, meanwhile, the buoy floats upwards, a circuit is connected, the motor rotates, and the sampling cavity is closed; and the fluid sealing effect is achieved without increasing the work load.

Description

Technical Field

[0001] This invention relates to the field of fluid sampling device technology, and more specifically to a downhole fluid surface sampler. Background Technology

[0002] After a gas lift in an oil or gas well, the fluid level is restored, or after fluid accumulates at the bottom of a gas well, in order to obtain fluid samples at the fluid level, the conventional approach is to first use an electronic pressure gauge to determine the fluid level depth, and then lower a retrieval cylinder to retrieve the fluid sample below the fluid level. The disadvantages of this approach are that it requires two operations, increasing workload and operating costs, and it is a non-closed sampling method, so the sample obtained may be a mixture of fluid from the fluid level to the maximum depth of the sampling cylinder.

[0003] For example, Chinese patent CN201071719 discloses a downhole fluid sampling device. Its structure includes an upper connector and a lower connector, with the upper and lower connectors connected to upper and lower tubing strings respectively via pipe threads. The upper and lower connectors are threaded to the main body. A sampling chamber is located in the middle of the main body. At the upper end of the sampling chamber are the upper end of a piston rod and an upper sealing seat. The lower end of the piston rod is integral with the upper end, and the upper sealing seat is fixed to the main body. A lower sealing seat is located at the lower end of the sampling chamber and is fixed to the main body. A one-way valve is located inside the upper sealing seat. A fluid flow channel is located below the upper connector. A circumferential fluid outlet is located above the upper end of the piston rod. A circumferential fluid inlet is located inside the lower sealing seat. A locking ring is located inside the lower sealing seat. A combustion chamber is threaded to the lower connector and contains combustible chemicals. A controller is connected to the combustion chamber. However, this patent still suffers from the aforementioned problems.

[0004] Therefore, it is necessary to design a sampling device that can solve problems such as high workload and non-closed sampling. Summary of the Invention

[0005] This invention addresses the problems existing in the prior art by providing a downhole fluid surface sampler.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A downhole fluid surface sampler includes a power assembly, a control assembly, and a sampling assembly. The power assembly includes an upper connector, a power chamber outer cylinder, an elastic element, a drive component, and a battery unit. The power chamber outer cylinder is fitted outside the upper connector, and the elastic element is fitted outside the power chamber outer cylinder. The drive component and battery unit are located inside the power chamber outer cylinder. The control assembly includes a control chamber outer cylinder. The sampling assembly includes a sampling valve and a sampling chamber. One end of the control chamber outer cylinder is connected to the elastic element via a connecting assembly, and the other end of the control chamber outer cylinder is connected to one end of the sampling chamber via a connecting assembly. The other end of the sampling chamber is connected to the sampling valve. When the sampler is inserted into the well, the drive component and battery unit provide power to the sampler, which is then transmitted to the elastic element. The elastic force of the elastic element pushes the control chamber outer cylinder and the sampling chamber downward, closing the sampling chamber and thus obtaining the sealed fluid at the surface.

[0008] Based on the above technical solution, the battery unit further includes a battery pack and a battery holder, one end of which is connected to the upper connector and the battery holder is located inside the outer cylinder of the power compartment; the battery pack is installed inside the battery holder.

[0009] Based on the above technical solution, the control component further includes a locking nut with internal threads, and the outer cylinder of the power compartment has an external thread structure, with the locking nut threadedly connected to the outer cylinder of the power compartment.

[0010] Based on the above technical solution, the control component further includes a pressure sleeve, which is threaded onto the outside of the power compartment outer cylinder and is located between the elastic element and the locking nut.

[0011] Based on the above technical solution, the driving component further includes a planetary geared motor, a bracket and brushes, and the connecting component includes a first connecting joint. The planetary geared motor and brushes are both mounted on the bracket. One end of the first connecting joint is located inside the outer cylinder of the power compartment and connected to the bracket, and the other end of the first connecting joint is located inside the outer cylinder of the control compartment.

[0012] Based on the above technical solution, the control component further includes a locking steel ball, a cross groove, and a connecting sleeve. The locking steel ball, the cross groove, and the connecting sleeve are all located inside the outer cylinder of the control compartment. The planetary geared motor outputs power to one end of the cross groove. One end of the cross groove is fitted with a first connecting joint and a connecting sleeve. The connecting sleeve is threaded to one end of the first connecting joint, and the connecting sleeve is provided with an installation hole, in which a locking steel ball is provided.

[0013] Based on the above technical solution, further, the first connecting joint is provided with a plurality of first mounting grooves, each first mounting groove is provided with a first sealing ring, the first connecting joint and the outer cylinder of the power compartment are fitted with at least one first sealing ring, and the first connecting joint and the connecting sleeve are connected with at least one first sealing ring.

[0014] Based on the above technical solution, the connecting assembly further includes a second connecting joint located inside the outer cylinder of the control chamber. One end of the cross groove is also fitted with a second connecting joint, which is threaded to one end of the connecting sleeve. The second connecting joint and the first connecting joint are located on both sides of the locking steel ball.

[0015] Based on the above technical solution, further, the second connecting joint is provided with a plurality of second mounting grooves, each second mounting groove is provided with a second sealing ring, and the connection position between the second connecting joint and the connecting sleeve is provided with at least one second sealing ring.

[0016] Based on the above technical solution, the connecting assembly further includes a third connecting joint, and the control assembly includes a reed switch, a magnet, and a float. The reed switch, magnet, and float are all located inside the outer cylinder of the control chamber. The third connecting joint is sleeved on the outside of the float, and one end of the third connecting joint is threadedly connected to the second connecting joint. The third connecting joint has a through hole, and the float corresponds to the position of the through hole. The magnet is fixed at the upper end of the float. Under the action of buoyancy, the float drives the magnet to move upward, reducing the distance between the magnet and the reed switch until the two electrode contacts of the reed switch are in contact, so that the circuit of the downhole fluid sampler is turned on.

[0017] Based on the above technical solution, the connecting assembly further includes a fourth connecting connector, one end of which is threadedly connected to the third connecting connector. The sampling chamber includes a sampling chamber outer sleeve and a sampling chamber inner sleeve. The sampling chamber outer sleeve is fitted outside the sampling chamber inner sleeve, and the other end of the fourth connecting connector is threadedly connected to the sampling chamber inner sleeve.

[0018] Based on the above technical solution, further, the fourth connecting joint is provided with a plurality of third mounting grooves, each third mounting groove is provided with a third sealing ring, the connection position between the fourth connecting joint and the third connecting joint is provided with at least one third sealing ring, and the connection position between the fourth connecting joint and the inner sleeve of the sampling chamber is provided with at least one third sealing ring.

[0019] Based on the above technical solution, further, both the inner sleeve and the outer sleeve of the sampling chamber are provided with a number of liquid inlet holes, and the inner sleeve of the sampling chamber is also provided with a fourth mounting groove. Each fourth mounting groove is provided with a fourth sealing ring, and the fourth sealing ring is located at the liquid inlet hole position of the inner sleeve of the sampling chamber.

[0020] Based on the above technical solution, the sampling valve further includes a valve core and a valve body. The valve core is installed inside the valve body. Rotating the valve core depressurizes and releases the sampling chamber. One end of the valve body is threadedly connected to the inner wall of the inner sleeve of the sampling chamber.

[0021] Based on the above technical solution, a fifth mounting groove is further provided at one end of the valve body, and a fifth sealing ring is provided in the fifth mounting groove. The fifth sealing ring is located at the position where the inner sleeve of the sampling chamber connects to the valve body.

[0022] Based on the above technical solution, the elastic element is further described as a helical spring.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This invention involves hanging the improved sampler below a conventional well test tool string and lowering the instrument string according to the conventional well test operation procedure. Once the sampler enters the fluid below the liquid surface, the fluid enters the sampling chamber through the upper and lower inlet holes, causing the float to rise, the circuit to be connected, the motor to rotate, and the sampling chamber to close. In this way, a sealed fluid is achieved without increasing the workload. At the same time, the workload can be reduced through one-time automated operation. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the sampler of the present invention;

[0026] Figure 2 This is an enlarged schematic diagram of the front end of the sampler of the present invention;

[0027] Figure 3 This is an enlarged schematic diagram of the middle part of the sampler of the present invention;

[0028] Figure 4 This is an enlarged schematic diagram of the structure of the end portion of the sampler of the present invention;

[0029] Reference numerals: 1. Upper connector; 2. Power compartment outer cylinder; 3. Battery support cylinder; 4. Locking nut; 5. Pressure sleeve; 6. Battery pack; 7. Helical spring; 8. Planetary geared motor; 9. Bracket; 10. Brush; 11. Locking ball; 12. Cross groove; 13. Reed switch; 14. Magnet; 15. Control compartment outer cylinder; 16. Float; 17. Sampling chamber outer sleeve; 18. Sampling chamber inner sleeve; 19. Valve core; 20. Valve body; 21. First connecting connector; 22. Second connecting connector; 23. Third connecting connector; 24. Fourth connecting connector; 25. First sealing ring; 26. Second sealing ring; 27. Third sealing ring; 28. Fourth sealing ring; 29. ​​Fifth sealing ring; 30. Liquid inlet; 31. Liquid outlet; 32. Connecting sleeve. Detailed Implementation

[0030] The present invention will be further described and illustrated below with reference to the accompanying drawings and specific embodiments. The technical features of each embodiment of the present invention can be combined accordingly, provided that there is no mutual conflict.

[0031] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of the present invention. However, the present invention can be practiced in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. Technical features in the various embodiments of the present invention can be combined accordingly without mutual conflict.

[0032] In the description of this invention, it should be understood that when an element is considered to be "connected" to another element, it can be a direct connection to the other element or an indirect connection, i.e., there is an intermediate element. Conversely, when an element is said to be "directly" connected to another element, there is no intermediate element.

[0033] Example

[0034] Combination Figures 1-4 As shown, a downhole fluid surface sampler is implemented, which includes a power component, a control component, and a sampling component. The power component, control component, and sampling component are arranged sequentially, and the power component and control component, and the control component and sampling component are connected by a connecting component. The power component serves as the power part of the downhole fluid surface sampler; the control component serves as the control part of the downhole fluid surface sampler; the sampling component serves as the downhole fluid surface sampling part; and the connecting component serves as a connection and sealing component.

[0035] The power assembly includes an upper connector 1, a power compartment outer cylinder 2, an elastic element, a drive element, and a battery unit. The upper connector 1 is fitted with the power compartment outer cylinder 2. The outer surface of the power compartment outer cylinder 2 is divided into two parts: one part is a threaded structure and the other part is a flat structure. A step is provided between the threaded structure part and the flat structure part, and the threaded structure part and the flat structure part are integral. The elastic element is fitted on the flat structure part of the power compartment outer cylinder 2, and the elastic element can preferably be a helical spring 7. The drive element and the battery unit are located inside the power compartment outer cylinder 2, and the corresponding external parts of the drive element and the battery unit are fitted with helical springs 7. Specifically, the driving components include a planetary geared motor 8, a bracket 9, and a brush 10. The connecting components include a first connecting joint 21. One end of the planetary geared motor 8 is mounted on the bracket 9, and the brush 10 is also mounted on the bracket 9. One end of the first connecting joint 21 is located inside the outer cylinder 2 of the power compartment and is connected to the bracket 9 by bolts or other means, while the first connecting joint 21 is connected to the inside of the outer cylinder 2 of the power compartment by threads. The other end of the first connecting joint 21 is located inside the outer cylinder 15 of the control compartment, and the two are also connected by threads. The brush 10 is an important component of the planetary geared motor 8, responsible for conducting current between the rotating and stationary parts. The working process between the planetary geared motor 8 and the brush 10 is a current method and will not be described in detail here.

[0036] The battery unit includes a battery pack 6 and a battery holder 3. One end of the battery holder 3 is fixedly connected to the upper connector 1, and the battery holder 3 is located inside the outer cylinder 2 of the power chamber. The battery pack 6 is connected in series with the planetary geared motor 8. The number of battery packs 6 installed inside the battery holder 3 can be determined according to actual conditions. During actual well entry, the compression helical spring 7 can store a certain amount of elastic force, which serves as the power to push the outer cylinder 15 of the control chamber and the outer sleeve 17 of the sampling chamber downward. The battery pack 6 and the planetary geared motor 8 provide power for the sampler to enter the liquid surface, causing the cross groove 12 to rotate, retracting the locking steel ball 11 and releasing the outer cylinder 15 of the control chamber.

[0037] The control assembly includes a control chamber outer cylinder 15, a locking ball 11, a cross groove 12, a reed switch 13, a magnet 14, a float 16, a locking nut 4 with internal threads, a pressure sleeve 5, and a connecting sleeve 32. The control chamber outer cylinder 15 is connected to one end of a helical spring 7, and the other end of the helical spring 7 is connected to the pressure sleeve 5, which is sleeved on the outside of the power chamber outer cylinder 2. The pressure sleeve 5 is located between the helical spring 7 and the locking nut 4. Specifically, the locking nut 4 is located in the threaded part of the power chamber outer cylinder 2 and is threadedly connected to the power chamber outer cylinder 2. By rotating the locking nut 4, the pressure sleeve 5 is pushed downward to compress the helical spring 7. The locking steel ball 11, the cross groove 12, and the connecting sleeve 32 are all located inside the outer cylinder 15 of the control compartment. The planetary geared motor 8 outputs power to one end of the cross groove 12. The two ends of the cross groove 12 are concave, and the middle part of the two concave is a convex part. A first connecting joint 21 is fitted onto one concave end of the cross groove 12. The connecting sleeve 32 is threaded onto one end of the first connecting joint 21. The connecting sleeve 32 has an installation hole, and the locking steel ball 11 is installed in the installation hole. The locking steel ball 11 is positioned opposite the convex part of the cross groove 12. Specifically, the first connecting joint 21 has several first installation grooves. Each first installation groove has a first sealing ring 25. At least one first sealing ring 25 is provided at the position where the first connecting joint 21 is fitted onto the outer cylinder 2 of the power compartment, and at least one first sealing ring 25 is provided at the position where the first connecting joint 21 is connected to the connecting sleeve 32. When entering the well, the locking steel ball 11 can be locked in the gap between the protrusion and the connecting sleeve 32. When the locking steel ball 11 is released, the outer cylinder 15 of the control chamber moves downward under the elastic force of the helical spring 7.

[0038] The connecting assembly further includes a second connecting joint 22 and a third connecting joint 23. The second connecting joint 22 is located inside the outer cylinder 15 of the control compartment. The second connecting joint 22 is fitted into the recess at the other end of the cross groove 12. The second connecting joint 22 is threadedly connected to the other end of the connecting sleeve 32. The second connecting joint 22 and the first connecting joint 21 are located on both sides of the locking ball, that is, respectively located on the recesses at both ends of the cross groove 12. Specifically, the second connecting joint 22 is provided with a plurality of second mounting grooves, and each second mounting groove is provided with a second sealing ring 26. At least one second sealing ring 26 is provided at the connection position between the second connecting joint 22 and the connecting sleeve 32. The reed switch 13, magnet 14, and float 16 in the control assembly are all located inside the outer cylinder 15 of the control chamber. The third connecting joint 23 is sleeved on the outside of the float 16, and one end of the third connecting joint 23 is threadedly connected to the second connecting joint 22. The third connecting joint 23 has a through hole, and the float 16 is positioned corresponding to the through hole. The magnet 14 is fixed to the upper end of the float 16. Under the action of buoyancy, the float 16 drives the magnet 14 to move upward. The distance between the magnet 14 and the reed switch 13 decreases until the two electrode contacts of the reed switch 13 make contact, so that the circuit of the downhole fluid sampler is turned on.

[0039] During actual well entry, the locking steel ball 11 is held in place by the protrusion of the cross groove 12, locking the control chamber outer cylinder 15 and preventing it from descending. The magnet 14 is fixed to the upper end of the float 16. During well entry, under the action of gravity, the float 16 is at the lowest end of the control chamber outer cylinder 15, and the magnet 14 maintains a certain distance from the reed switch 13. When the downhole fluid sampler enters the fluid below the surface, the float 16 drives the magnet 14 upward under the action of buoyancy. After the distance between the float 16 and the reed switch 13 decreases to a certain value, the two electrode contacts of the reed switch 13 make contact, causing the circuit of the downhole fluid sampler to be connected. The planetary geared motor 8 drives the cross groove 12 to rotate. When the concave part on the cross groove 12 rotates to the position of the locking steel ball 11, the locking steel ball 11 retracts, the control chamber outer cylinder 15 is released, and it descends under the action of the elastic force of the helical spring 7.

[0040] The sampling assembly includes a sampling valve and a sampling chamber. One end of the sampling chamber is connected to the outer cylinder 15 of the control chamber, and the other end is connected to the sampling valve. The connection assembly also includes a fourth connecting joint 24, one end of which is threadedly connected to a third connecting joint 23. Specifically, the sampling chamber includes a sampling chamber outer sleeve 17 and a sampling chamber inner sleeve 18. The sampling chamber outer sleeve 17 is fitted over the sampling chamber inner sleeve 18, and the other end of the fourth connecting joint 24 is threadedly connected to the sampling chamber inner sleeve 18. The fourth connecting joint 24 is provided with several third mounting grooves, each of which contains a third sealing ring 27. At least one third sealing ring 27 is provided at the connection position between the fourth connecting joint 24 and the third connecting joint 23, and at least one third sealing ring 27 is provided at the connection position between the fourth connecting joint 24 and the sampling chamber inner sleeve 18. Furthermore, both the inner sleeve 18 and the outer sleeve 17 of the sampling chamber are provided with several liquid inlet holes 30, and the inner sleeve 18 of the sampling chamber is also provided with a fourth mounting groove. Each fourth mounting groove contains a fourth sealing ring 28, and the fourth sealing ring 28 is located at the position of the liquid inlet hole 30 of the inner sleeve 18 of the sampling chamber. The discharge valve includes a valve core 19 and a valve body 20. The valve core 19 is installed inside the valve body 20. Rotating the valve core 19 depressurizes and discharges the sampling chamber. One end of the valve body 20 is threadedly connected to the inner wall of the inner sleeve 18 of the sampling chamber. A fifth mounting groove is provided at one end of the valve body 20. A fifth sealing ring 29 is provided in the fifth mounting groove and is located at the position where the inner sleeve 18 of the sampling chamber is connected to the valve body 20. Specifically, the upper and lower ends of the sampling chamber outer sleeve 17 and the sampling chamber inner sleeve 18 are each provided with four liquid inlet holes. Each liquid inlet hole of the sampling chamber inner sleeve 18 is equipped with a fourth sealing ring 28. During well insertion, the liquid inlet holes 30 of the sampling chamber inner sleeve 18 and the sampling chamber outer sleeve 17 are aligned, allowing fluid to enter freely. When the upper and lower liquid inlet holes 30 of the sampling chamber outer sleeve 17 descend below the corresponding fourth sealing ring, that is, after the sampling chamber outer sleeve 17 has descended a certain distance, the liquid inlet holes 30 of the sampling chamber outer sleeve 17 are closed, trapping the incoming fluid. The first, second, third, fourth, and fifth sealing rings are preferably O-rings.

[0041] The sampler's discharge valve body 20 and lower connector are integrated. The discharge valve is preferably a needle-type pressure relief valve; pressure relief and discharge of the sampling chamber can be achieved by rotating the valve core 19. Using this downhole fluid surface sampler, during well testing, the tool is lowered normally. Once the tool enters the fluid below the surface, the fluid enters the sampling chamber, simultaneously buoying the float 16 and magnet 14. The magnet 14 approaches the reed switch 13, causing the reed switch 13's contacts to engage, thus completing the circuit. This circuit activation causes the motor to rotate, which rotates the cross groove 12 by a certain angle. After this rotation, the locking ball 11 is released, and the spring force of the helical spring 7 pushes the control chamber outer cylinder 15 and the sampling chamber outer sleeve 17 downwards, closing the sampling chamber and obtaining the sealed fluid at the surface. During operation, when the valve core 19 moves, the outlet hole 31 is not blocked, and fluid flows out from the outlet hole 31. Specifically, after the valve body 20 and valve core 19 are tightened in place, the inner surface of the valve body 20 contacts the outer surface of the valve core 19. The metal seal is achieved by tightening the valve core 19 and the valve body 20 through the threaded pressure through the tool, which can prevent the sampled liquid from leaking out. The tightening tool can be a wrench or the like.

[0042] Based on the specific structure of a downhole fluid surface sampler, its implementation process includes: during operation, connecting the upper connector 1 of the sampler to the well test tool string and performing a downhole operation; wherein, the upper part of the upper connector 1 is a quick connector; when entering the well, activating the drive unit and battery unit, driving the elastic element to move; under the elastic force of the elastic element, driving the outer cylinder 15 of the control chamber and the sampling chamber downward, closing the sampling chamber, and thus obtaining the sealed fluid surface; after the sampler is pulled out from the wellhead, depressurization and sampling are performed by adjusting the sampling valve.

[0043] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A downhole fluid surface sampler, characterized in that, Includes power components, control components, and sampling components; The power assembly includes an upper connector, a power compartment outer cylinder, an elastic element, a drive element, and a battery unit. The power compartment outer cylinder is fitted over the upper connector, and an elastic element is fitted over the power compartment outer cylinder. The drive element and battery unit are located inside the power compartment outer cylinder. The control assembly includes a control chamber outer cylinder, and the sampling assembly includes a sampling valve and a sampling chamber. One end of the control chamber outer cylinder is connected to an elastic element through a connecting assembly, and the other end of the control chamber outer cylinder is connected to one end of the sampling chamber through a connecting assembly. The other end of the sampling chamber is connected to the sampling valve. When the sampler is inserted into the well, the power is provided by the drive unit and the battery unit. The power is transmitted to the elastic element. The elastic force of the elastic element pushes the outer cylinder of the control chamber and the sampling chamber downward. The sampling chamber closes, thereby obtaining the sealed fluid at the liquid surface.

2. The downhole fluid level sampler according to claim 1, characterized in that, The battery unit includes a battery pack and a battery holder. One end of the battery holder is connected to the upper connector, and the battery holder is located inside the outer cylinder of the power compartment. The battery pack is installed inside the battery holder.

3. The downhole fluid level sampler according to claim 1, characterized in that, The control component includes a locking nut with internal threads, and the outer cylinder of the power compartment has an external thread structure. The locking nut is threadedly connected to the outer cylinder of the power compartment.

4. A downhole fluid surface sampler according to claim 3, characterized in that, The control component includes a pressure sleeve, which is threaded onto the outside of the power compartment outer cylinder and is located between the elastic element and the locking nut.

5. A downhole fluid surface sampler according to claim 1, characterized in that, The drive component includes a planetary geared motor, a bracket, and brushes. The connecting assembly includes a first connecting joint. The planetary geared motor and brushes are both mounted on the bracket. One end of the first connecting joint is located inside the outer cylinder of the power compartment and connected to the bracket. The other end of the first connecting joint is located inside the outer cylinder of the control compartment.

6. A downhole fluid surface sampler according to claim 5, characterized in that, The control component includes a locking steel ball, a cross groove, and a connecting sleeve. The locking steel ball, the cross groove, and the connecting sleeve are all located inside the outer cylinder of the control compartment. The planetary geared motor outputs power to one end of the cross groove. A first connecting joint and a connecting sleeve are fitted onto one end of the cross groove. The connecting sleeve is threaded to one end of the first connecting joint, and the connecting sleeve has an installation hole with a locking steel ball inside the installation hole.

7. A downhole fluid surface sampler according to claim 6, characterized in that, The first connecting joint is provided with a plurality of first mounting grooves, each first mounting groove is provided with a first sealing ring, the first connecting joint and the outer cylinder of the power compartment are fitted with at least one first sealing ring, and the first connecting joint and the connecting sleeve are connected with at least one first sealing ring.

8. A downhole fluid surface sampler according to claim 6, characterized in that, The connecting assembly also includes a second connecting joint located inside the outer cylinder of the control compartment. One end of the cross groove is also fitted with a second connecting joint, which is threaded to one end of the connecting sleeve. The second connecting joint and the first connecting joint are located on both sides of the locking steel ball.

9. A downhole fluid surface sampler according to claim 8, characterized in that, The second connecting joint is provided with a plurality of second mounting grooves, each second mounting groove is provided with a second sealing ring, and the connection position between the second connecting joint and the connecting sleeve is provided with at least one second sealing ring.

10. A downhole fluid surface sampler according to claim 9, characterized in that, The connection assembly also includes a third connection joint, and the control assembly also includes a reed switch, a magnet, and a float. The reed switch, magnet, and float are all located inside the outer cylinder of the control chamber. The third connection joint is sleeved on the outside of the float, and one end of the third connection joint is threadedly connected to the second connection joint. The magnet is fixed to the upper end of the float. Under the action of buoyancy, the float drives the magnet to move upward, reducing the distance between the magnet and the reed switch until the two electrode contacts of the reed switch are in contact, so that the circuit of the downhole fluid sampler is turned on.

11. A downhole fluid surface sampler according to claim 10, characterized in that, The connecting assembly further includes a fourth connecting connector, one end of which is threadedly connected to the third connecting connector. The sampling chamber includes a sampling chamber outer sleeve and a sampling chamber inner sleeve. The sampling chamber outer sleeve is fitted outside the sampling chamber inner sleeve, and the other end of the fourth connecting connector is threadedly connected to the sampling chamber inner sleeve.

12. A downhole fluid surface sampler according to claim 11, characterized in that, The fourth connecting joint is provided with a plurality of third mounting grooves, each third mounting groove is provided with a third sealing ring, the connection position between the fourth connecting joint and the third connecting joint is provided with at least one third sealing ring, and the connection position between the fourth connecting joint and the inner sleeve of the sampling chamber is provided with at least one third sealing ring.

13. A downhole fluid surface sampler according to claim 12, characterized in that, The inner sleeve and outer sleeve of the sampling chamber are provided with several liquid inlet holes, and the inner sleeve of the sampling chamber is also provided with a fourth mounting groove. Each fourth mounting groove is provided with a fourth sealing ring, and the fourth sealing ring is located at the liquid inlet hole of the inner sleeve of the sampling chamber.

14. A downhole fluid surface sampler according to any one of claims 11-13, characterized in that, The sampling valve includes a valve core and a valve body. The valve core is installed inside the valve body. Rotating the valve core depressurizes and releases the sample from the sampling chamber. One end of the valve body is threadedly connected to the inner wall of the inner sleeve of the sampling chamber.

15. A downhole fluid surface sampler according to claim 14, characterized in that, A fifth mounting groove is provided at one end of the valve body, and a fifth sealing ring is provided in the fifth mounting groove. The fifth sealing ring is located at the position where the inner sleeve of the sampling chamber connects to the valve body.

16. A downhole fluid surface sampler according to claim 1, characterized in that, The elastic element is a helical spring.

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