A pressure-maintaining electric sampler, its use method and related applications

Abstract

The application discloses a kind of pressure-maintaining electric sampler and its use method and related application.The sampler driving part is connected with valve core to drive valve core up and down movement, valve core is connected with the valve and drives the valve up and down movement to open or close the first liquid inlet passage for communicating central hole on body assembly;Second liquid inlet passage is opened in liquid storage tank and communicated with the first liquid inlet passage, ball rod is compressed spring under the liquid pressure from the first liquid inlet passage and opens second liquid inlet passage to make liquid enter liquid storage tank, and after sampling is completed, second liquid inlet passage is closed under the restoring force of spring, after sampling is completed, liquid pressure in liquid storage tank acts on ball rod to maintain the constancy of liquid pressure in liquid storage tank, compared with traditional sampler, the authenticity of in-situ pressure and other parameters of produced sample liquid is guaranteed and faithfully lifted to ground, the accuracy of reservoir physical property detection is improved, valuable data reference is provided for understanding real formation reservoir dynamic condition.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of oil production engineering equipment, in particular to a pressure-maintaining electric sampler and a use method thereof and related applications. BACKGROUND

[0002] In the middle and late stages of onshore oilfield development, with the continuous deepening of development, the interlayer and plane contradictions become increasingly prominent, and low-permeability reservoirs are difficult to effectively develop. At the same time, after water injection development, the reservoir properties change, the interlayer difference increases year by year, and the oil-water distribution becomes increasingly complex. Therefore, accurately grasping various reservoir property parameters is of great significance to improve the ultimate recovery. At present, the commonly used reservoir property detection means for oil production wells mainly includes two kinds, which are sampling and pressure measurement. The commonly used mechanical pipe string layered pressure testing technology and the layered pressure measurement technology with pump all have problems of harsh implementation conditions, complicated procedures, low efficiency, long cycle and high cost. For the special circumstances of some oil wells, the commonly used sampling test technology is feasible in principle, but the current sampling test technology still has problems of narrow sealing range of packer, too complex system and low reliability. And the reliability of the sampler as the core tool of the sampling and pressure testing technology of the oil production well affects the success rate of the whole system construction. SUMMARY

[0003] The present application relates to the field of oil production engineering equipment, in particular to a pressure-maintaining electric sampler and a use method thereof and related applications.

[0004] In view of the above problems, the present application is proposed to provide a pressure-maintaining electric sampler and a use method thereof and related applications which overcome the above problems or at least partially solve the above problems.

[0005] The present application provides a pressure-maintaining electric sampler, comprising: a body assembly, a driving component, a sampling control assembly and a liquid storage assembly arranged in the cavity of the body assembly;

[0006] The body assembly is provided with a central channel;

[0007] The sampling control assembly comprises a valve core and a valve;

[0008] The driving component is connected with the valve core to drive the valve core to move up and down, and the valve core is connected with the valve to drive the valve to move up and down to open or close the first liquid inlet passage of the body assembly for communicating with the central channel;

[0009] The liquid storage assembly comprises a liquid storage tank, a ball rod arranged in the liquid storage tank, and a spring nested on the ball rod; a second liquid inlet channel is arranged on the liquid storage tank and communicates with the first liquid inlet channel; the ball rod compresses the spring under the pressure of liquid from the first liquid inlet channel, opens the second liquid inlet channel to allow liquid to enter the liquid storage tank, and closes the second liquid inlet channel under the restoring force of the spring after sampling is completed.

[0010] In some optional embodiments, the first liquid inlet channel comprises a first liquid inlet through hole and a second liquid inlet through hole;

[0011] The first liquid inlet through hole communicates with the central channel, and the second liquid inlet through hole is a first tapered hole at one end connected with the first liquid inlet through hole; the lower end of the valve cooperates with the first tapered hole to control opening or closing of the first liquid inlet channel.

[0012] In some optional embodiments, the second liquid inlet channel comprises a straight through hole and a second tapered hole; the spherical end of the ball rod cooperates with the second tapered hole to control opening or closing of the second liquid inlet channel.

[0013] In some optional embodiments, the liquid storage tank comprises a valve seat, a liquid storage pipe, and a threaded plug;

[0014] The valve seat, the liquid storage pipe, and the threaded plug are sequentially connected in a sealing manner to form the liquid storage tank.

[0015] The valve seat is mounted on the valve body, the second liquid inlet channel is arranged on the valve seat, and the ball rod is mounted in the liquid storage pipe.

[0016] In some optional embodiments, at least one liquid inlet hole is arranged on the liquid storage pipe; the liquid inlet hole communicates with the inner cavity of the liquid storage pipe and the cavity formed by the valve seat and the liquid storage pipe, so that liquid entering the cavity through the second liquid inlet channel enters the inner cavity of the liquid storage pipe through the liquid inlet hole.

[0017] In some optional embodiments, the body assembly comprises a circuit board frame, a first cylinder sleeve, a second cylinder sleeve, a valve body, a third cylinder sleeve, and a body;

[0018] The circuit board frame, the valve body, and the body are sequentially connected to form the central channel.

[0019] The first cylinder sleeve is mounted outside the circuit board frame, the second cylinder sleeve is mounted outside the circuit board frame and the valve body, and the third cylinder sleeve is mounted outside the valve body and the body to form a body assembly cavity.

[0020] The first cylinder sleeve, the second cylinder sleeve and the circuit board frame form a driving component mounting cavity; the valve body, the third cylinder sleeve and the body form the liquid storage assembly mounting cavity; and the valve body is provided with a sampling assembly mounting hole.

[0021] In some optional embodiments, the body assembly cavity is further provided with a cable passage for the cable to pass through the pressure maintaining electric sampler.

[0022] The cable is sealed with the circuit board frame and the body through a sealing joint.

[0023] In some optional embodiments, the driving component comprises a mounting frame, a motor, a lead screw, a transmission sleeve and a nut.

[0024] The motor is fixed on the mounting frame, the lead screw is mounted on the mounting frame, the motor is connected with the lead screw to drive the rotation of the lead screw, the lead screw drives the nut to move up and down, and the nut is connected with the transmission sleeve to drive the transmission sleeve to move up and down.

[0025] In some optional embodiments, the transmission sleeve is provided with an anti-rotation groove inside, and an anti-rotation pin is arranged in the anti-rotation groove.

[0026] In some optional embodiments, the transmission sleeve is provided with a threaded hole at the lower end, and the lead screw is connected with the transmission sleeve through threads.

[0027] In some optional embodiments, the mounting frame comprises a motor seat, a bearing seat and a valve sleeve.

[0028] The motor is fixed on the motor seat, the bearing seat is arranged in the motor seat, and the valve sleeve is connected with the motor seat and the valve body in sequence.

[0029] The transmission sleeve is arranged in the inner cavity of the valve sleeve, a sliding groove is formed on the inner wall of the valve sleeve, and the anti-rotation pin penetrates through the transmission sleeve and slides up and down in the sliding groove under the action of the lead screw.

[0030] The lead screw is arranged in the bearing seat, and two-stage bearings are arranged between the lead screw and the bearing seat.

[0031] In some optional embodiments, the sampler further comprises an upper connecting part and a lower connecting part.

[0032] The upper connecting part and the lower connecting part are respectively used for being connected with an external packer of the sampler.

[0033] Based on the same inventive concept, the embodiments of the present application further provide a use method of the pressure maintaining electric sampler, which is characterized by comprising the following steps.

[0034] After the control drive component is powered on, it drives the valve core and the valve to move upward, opening the first liquid inlet channel and allowing the sampled liquid to enter the second liquid inlet channel. Under the action of liquid pressure, the ball bar compresses the spring and the valve seat to create a gap, and the sampled liquid flows into the lower storage tank through the gap.

[0035] After sampling is completed, the control drive component drives the valve core and valve to move downward, closing the first liquid inlet channel. The ball bar is reset under the action of the spring, and the ball bar cooperates with the valve seat to seal the liquid storage tank.

[0036] This invention also provides an application of the above-described sampler in a downhole sampling system.

[0037] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0038] The pressure-holding electric sampler provided in this embodiment of the invention has a driving component connected to a valve core to drive the valve core to move up and down. The valve core is connected to a valve, which drives the valve to move up and down to open or close the first liquid inlet channel on the main body assembly for connecting the central channel, thereby controlling the entry of liquid samples in the central channel into the first liquid inlet channel. The sampler's storage tank has a second liquid inlet channel connected to the first liquid inlet channel. The ball rod, under the action of liquid pressure from the first liquid inlet channel, compresses the spring and opens the second liquid inlet channel to allow liquid to enter the storage tank. After sampling, the second liquid inlet channel is closed under the action of the spring's restoring force. In this embodiment of the invention, when the second liquid inlet channel is closed after sampling, the liquid pressure in the storage tank acts on the ball rod to maintain the sampling liquid pressure in the storage tube unchanged, ensuring the authenticity of the in-situ pressure and other parameters of the collected liquid sample and accurately bringing it to the surface. This provides more accurate liquid samples for subsequent analysis, improves the accuracy of reservoir property detection, and provides valuable data reference for understanding the dynamic conditions of the actual formation reservoir.

[0039] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0040] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0041] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0042] Figure 1This is a schematic diagram of the pressure-holding electric sampler in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of a downhole sampling system in an embodiment of the present invention.

[0044] Explanation of reference numerals in the attached figures:

[0045] 1-Upper connector, 2-Cable branch sleeve, 3-Anti-rotation pin, 4-Small nut, 5-Sealing connector, 6-Circuit board frame, 7-First cylinder liner, 8-Circuit board, 9-Second cylinder liner, 10-Motor, 11-Screw, 12-Flat key, 13-Coupling sleeve, 14-Motor mount, 15-First bearing, 16-Bearing seat, 17-Second bearing, 18-Lead screw, 19-Valve sleeve, 20-Nut, 21-Pressure plate, 22-Transmission sleeve, 23-Hall switch, 24-Positioning pin, 25-Connecting nut, 26-Valve body, 27-Seal, 28-Valve core, 29-Connecting sleeve, 30-Small spring, 31-Valve 32-Third cylinder liner, 33-Valve seat, 34-Ball bar, 35-Spring, 36-Reservoir tube, 37-Plug, 38-Body, 39-Lower connector, 40-Sealing insert, 41-Connecting nut, 42-Sealing ring, 43-Anti-rotation pin, 44-Spacer, 45-Retaining ring, 46-Central channel, 47-First inlet channel, 48-Second inlet channel, 49-Inlet hole, 50-Ground control system, 51-Power module, 52-Dispensing pump, 53-Anchor, 54-First packer, 55-Pressure-holding electric sampler, 56-Second packer, 57-Magnetic positioning device, 58-Terminal short section.

[0046] 471 - First liquid inlet hole; 472 - Second liquid inlet hole. Detailed Implementation

[0047] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0048] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] To address the problems existing in the prior art, embodiments of the present invention provide a pressure-holding electric sampler, its usage method, and related applications.

[0051] The pressure-holding electric sampler provided in this embodiment of the invention is used for sampling and pressure testing of stratified fluids. When sampling downhole fluids, the drive component drives the movement of the sampling control component to control the opening or closing of the first liquid inlet channel, thereby controlling the liquid inlet of the liquid storage component. After sampling is completed, the pressure of the sampled liquid acts on the liquid storage component, thereby ensuring that the extracted liquid sample maintains the authenticity of parameters such as in-situ pressure.

[0052] The structure of the pressure-holding electric sampler is as follows: Figure 1 As shown, it includes: a main body assembly and a driving component, a sampling control component, and a liquid storage component disposed within the cavity of the main body assembly;

[0053] The main body component has a central channel 46;

[0054] The sampling control assembly includes valve core 28 and valve 31;

[0055] The drive component is connected to the valve core 28 to drive the valve core 28 to move up and down. The valve core 28 is connected to the valve 31 and drives the valve 31 to move up and down to open or close the first liquid inlet channel 47 on the body assembly for connecting the central channel 46.

[0056] The liquid storage assembly includes a liquid storage tank, a ball rod 34 disposed inside the liquid storage tank, and a spring 35 nested on the ball rod 34; the liquid storage tank has a second liquid inlet channel 48 that communicates with the first liquid inlet channel 47. The ball rod 34 compresses the spring 35 and opens the second liquid inlet channel 48 under the liquid pressure from the first liquid inlet channel 47 to allow liquid to enter the liquid storage tank, and closes the second liquid inlet channel 48 under the restoring force of the spring 35 after sampling is completed.

[0057] In this pressure-holding electric sampler, during sampling, the drive component moves the valve core 28 and the valve 31 up and down. When the valve 31 moves upward, its lower end is separated from the first liquid inlet channel 47, meaning the first liquid inlet channel is open. The sampling liquid in the central channel 46 can flow into the lower second liquid inlet channel 48 through the first liquid inlet channel 47. The flow of the sampling liquid in the second liquid inlet channel 48 provides an axial thrust to the ball rod 34 that cooperates with the lower end of the second liquid inlet channel 48. Under the pressure, the ball rod compresses the spring 35 and moves downward, creating a gap between the ball rod 34 and the second liquid inlet channel 48. The sampling liquid enters the storage tank through the gap. After sampling, the movement of the control drive component drives the valve core 28 and valve 31 downward, closing the first liquid inlet channel 47. The ball rod 34 is reset under the elastic force of the spring 35. The ball rod 34 cooperates with the second liquid inlet channel 48 to seal the storage tank, stopping the liquid inlet and storing the sampled liquid inside. The pressure of the sampled liquid inside the storage tank acts on the ball rod 34, which can maintain the pressure of the sampled liquid at the sampling layer position, maximizing the authenticity of the sample parameters and providing detailed basic data for subsequent analysis of oil layer properties.

[0058] The sampler's first liquid inlet channel 47 includes a first liquid inlet through-hole 471 and a second liquid inlet through-hole 472. The first liquid inlet through-hole 471 connects to the central channel 46. The end of the second liquid inlet through-hole 472 connected to the first liquid inlet through-hole 471 is a first conical hole. The lower end of the valve 31 engages with the first conical hole to control the opening or closing of the first liquid inlet channel 47. That is, when the valve 31 is separated from the first conical hole, the first liquid inlet channel 47 is open; when the valve 31 is sealed with the first conical hole, the first liquid inlet channel 47 is closed. The second liquid inlet channel 48 includes a straight through-hole and a second conical hole. The spherical end of the ball 34 engages with the second conical hole to control the opening or closing of the second liquid inlet channel. That is, when the ball spherical end is separated from the second conical hole, the second liquid inlet channel is open; when the ball spherical end is sealed with the second conical hole, the second liquid inlet channel 48 is closed. The valve 31 and the first conical hole and the ball end of the ball rod 34 are connected by a curved surface seal. The structure is simple and can achieve a good sealing effect. At the same time, the structure of the first conical hole can play a role in concentrating the sampling liquid and accelerating the entry of the sampling liquid into the second liquid inlet hole 472.

[0059] Optionally, the lower end of the second liquid inlet through-hole 472 is connected to the upper straight through-hole of the second liquid inlet channel 48. The position of the straight through-hole of the second liquid inlet through-hole 472 is correspondingly set, and its specific size and shape can be set by the user, as long as the sampling liquid can flow into the second liquid inlet channel 48 through the second liquid inlet through-hole 472. At the connection between the second liquid inlet through-hole 472 and the second liquid inlet channel 48, the diameter of the second liquid inlet through-hole 472 can be greater than, less than or equal to the diameter of the lower straight through-hole. Regarding the setting of the diameter of the ball end of the ball rod 34 and the size of the second conical hole, the diameter of the ball end of the ball rod 34 only needs to be greater than the smallest end diameter of the second conical hole to achieve a sealing fit between the ball end of the ball rod 34 and the second conical hole. Its specific size can be set by the user, and the present invention does not limit it. The design of the lower end of the valve 31 fitting with the first conical hole is similar.

[0060] like Figure 1 As shown, the sampler's storage tank includes a valve seat 33, a storage tube 36, and a plug 37. The valve seat 33, storage tube 36, and plug 37 are sequentially and sealingly connected to form the storage tank. Sealing rings are provided between the storage tube 36 and the valve seat 37, and between the storage tube 36 and the plug 37, to seal the liquid inside the storage tank and maintain the pressure of the sampled liquid, preventing leakage. The valve seat 16 is mounted on the valve body 26 and has a second inlet channel 48. A ball rod 34 is placed inside the storage tube 36, and a spring 35 is provided between the ball rod 34 and the storage tube 36. The spring 35 has a large restoring force; when sampling stops, the spring 35's rebound effectively seals the second inlet channel, avoiding the problem of incomplete sealing of the second inlet channel due to impurities such as sand particles in the fluid during sampling.

[0061] In one embodiment, the sampler storage tube 36 is provided with at least one inlet hole 49, which connects the inner cavity of the storage tube 36 and the cavity formed by the valve seat 33 and the storage tube 36, so that the liquid entering the cavity through the second inlet channel 48 can enter the inner cavity of the storage tube 36 through the inlet hole 49. It should be noted that the number, size and shape of the inlet holes can be selected as long as the liquid inlet conditions are met, and the present invention does not limit them.

[0062] The sampler drive component includes: a mounting frame, a motor 10, a lead screw 18, a transmission sleeve 22, and a nut 20; the motor 10 is fixed on the mounting frame, the lead screw 18 is mounted on the mounting frame, the motor 10 is connected to the lead screw 18 to drive the lead screw 18 to rotate, the lead screw 18 drives the nut 20 to move up and down, the nut 20 is connected to the transmission sleeve 22 to drive the transmission sleeve 22 to move up and down, and an anti-rotation groove is opened on the inner side of the transmission sleeve 22, and an anti-rotation pin 43 is provided in the anti-rotation groove.

[0063] The drive component mounting bracket includes a motor base 14, a bearing housing 16, and a valve sleeve 19. The motor 10 is fixed on the motor base 14, the bearing housing 16 is located inside the motor base 14, and the valve sleeve 19 is connected to the motor base 14 and the valve body 26 in sequence. The transmission sleeve 22 is located in the inner cavity of the valve sleeve 19, and a sliding groove (not shown in the figure) is opened on the inner wall of the valve sleeve 19. The anti-rotation pin 43 passes through the transmission sleeve 22 and slides up and down in the sliding groove under the action of the lead screw 18. The lead screw 18 is located inside the bearing housing 16, and two-stage bearings, namely the first bearing 15 and the second bearing 17, are provided between the lead screw 18 and the bearing housing 16. The two-stage bearings effectively ensure the coaxiality of the lead screw 18 and the motor 10.

[0064] Optionally, the main body assembly includes a circuit board frame 6, a first cylinder liner 7, a second cylinder liner 9, a valve body 26, a third cylinder liner 32, and a main body 38.

[0065] The circuit board frame 6 is sequentially connected to the valve body 26 and the main body 38 to form a central channel 46;

[0066] The first cylinder liner 7 is installed outside the circuit board frame 6, the second cylinder liner 9 is installed outside the circuit board frame 6 and the valve body 26, and the third cylinder liner 32 is installed outside the valve body 26 and the body 38 to form the body assembly cavity.

[0067] The first cylinder liner 7 and the second cylinder liner 9, together with the circuit board frame 6, form a drive component mounting cavity; the valve body 26, the third cylinder liner 32, and the main body 38, together form a liquid storage component mounting cavity; the valve body 26 is provided with a sampling component mounting cavity. A cable channel is also provided within the main body component cavity for the cable to pass through the pressure-holding electric sampler and connect to the devices at both ends; the cable is sealed to the circuit board frame 6 and the main body 38 through a sealing joint 5, ensuring safe cable transmission while allowing for rapid assembly and disassembly on-site, resulting in high construction efficiency.

[0068] like Figure 1 The structure of the sampler shown is as follows:

[0069] Inside the drive component mounting cavity, the small nut 4 is connected to the upper inner hole of the circuit board frame 6. The circuit board frame 6 has a circuit board 8 in the middle. The circuit board is connected to the lower motor via a cable. The lower end of the motor 10 is connected to the upper end of the motor base 14 via a screw 11. The lower end of the motor base 14 is connected to the upper end of the valve sleeve 19. The lower end of the valve sleeve 19 is connected to the upper end of the valve body 26 via a connecting nut 25. A Hall switch 23 is provided on the outside of the valve sleeve 19. A pressure plate 21 is provided on the outside of the Hall switch 23. A keyway is provided on the outer side of the upper end of the lead screw 18. The output shaft of the motor 10 is positioned with the lead screw 18 by a flat key 12 and connected by a connecting sleeve 13 on the outer side of the flat key. The lower end of the lead screw 18 and the upper end of the transmission sleeve 22 are respectively connected to the nut 20. The transmission sleeve is also provided with a positioning pin 24. A retaining ring 45 and a bearing seat 16 are provided on the outer side of the lead screw 18. The bearing seat 16 is located inside the motor seat 14. A first bearing 15, a second bearing 17 and a spacer 44 are provided between the lead screw 18 and the bearing seat 16.

[0070] Inside the sampling component mounting hole, the upper end of the valve core 28 is connected to the lower end of the transmission sleeve of the drive component, and the lower end of the valve core 28 is connected to the upper end of the valve 31 through the connecting sleeve 29. A small spring 30 is provided between the lower end of the valve core 28 and the upper end of the valve 31. A sealing element 27 is provided between the valve body 26 and the valve core 28 to seal the valve body 26 and the valve core 28, preventing liquid in the sampling component from entering the upper drive component and causing damage to the circuit inside the drive component.

[0071] Inside the liquid storage assembly mounting cavity, the upper end of the valve seat 33 is located in the lower cavity of the valve body 26, and the lower end of the plug 37 is located in the upper hole of the body 38. The liquid storage assembly is a modular, detachable unit. After sampling is completed and the sampler is lifted to the ground, the body 38 and the third cylinder liner 32 can be removed. At this point, the liquid storage assembly can be completely removed from the sampler, and the entire assembly is sealed upon removal, ensuring the authenticity of the liquid sample. The entire liquid storage assembly is easy to assemble and disassemble, allowing for multiple, multi-segment sampling operations. Its independent structure also facilitates quick and easy sample transfer to the ground.

[0072] The sampler provided in this embodiment of the invention has a central channel 46. Before sampling, the central channel 46 provides a liquid inlet channel for tools such as packers at the bottom, ensuring the normal operation of the packers. Moreover, the central channel 46 is a straight hole, which reduces the throttling loss when the packers and other tools are fed in, compared to a bent central channel 46. In some cases, it may be necessary to lower other measuring and adjusting tools while sampling, such as sending some power tools via cable to measure other parameters. With the central channel 46 in the sampler, it is not necessary to remove the sampling tool string. Smaller diameter tools can be lowered through the central channel 46, so that other measuring and adjusting tools can be operated at the same time as sampling.

[0073] Optionally, for the pressure-holding electric sampler provided in this embodiment of the invention, multiple liquid storage components can be set in one sampler for sampling according to the required quantity of formation liquid sampling. Furthermore, the specific arrangement of the driving component, sampling control component, and liquid storage component structure within the sampler body assembly cavity can be selected based on whether the multiple liquid storage components are sampling simultaneously or separately. For example, when sampling multiple liquid storage components simultaneously, each liquid storage component can share one driving component and sampling control component. A channel communicating with the second liquid inlet hole 472 is provided on the valve body 26. When the sampling control component opens the second liquid inlet hole 472 directly controlled by the driving component under the action of the driving component, the sampling liquid enters the second liquid inlet hole 472 from the first liquid inlet hole 471. Since the second liquid inlets on the valve body 26 are interconnected, the sampling liquid can enter the drive through the connecting channel. The second liquid inlet hole directly controlled by the component is connected to other second liquid inlet holes. The liquid enters the corresponding storage component at the lower end through the second liquid inlet hole, completing the simultaneous sampling of different storage components. For example, when it is necessary to use a sampler to sample liquids at different times, multiple drive components, sampling control components, and storage components can be set in a sampler. Each drive component is connected to the circuit board in the sampler through a cable. The drive component to be activated is controlled by the ground control system, thereby realizing time-sharing sampling of different storage components. It should be noted that the specific number of storage components in the sampler can be selected as needed, provided that the process conditions are met. At the same time, as long as simultaneous and time-sharing sampling of the storage tank in the sampler can be achieved, the specific design of the drive components, sampling control components, and storage components is not limited to the form in the example, and can be designed by oneself.

[0074] In one embodiment, the sampler further includes an upper connecting portion and a lower connecting portion; the upper connecting portion and the lower connecting portion are respectively used to connect to an external packer of the sampler.

[0075] Optionally, the upper connecting part includes an upper connector 1 and a cable branch sleeve 2. The lower ends of the upper connector 1 and the cable branch sleeve 2 are respectively connected to the upper end of the circuit board frame 6, and an anti-rotation pin 3 is provided between the cable branch sleeve 2 and the circuit board frame 6. The lower connecting part includes a lower connector 39, a sealing tube 40, a connecting nut 41, and a sealing ring 42. The upper end of the lower connector 39 is connected to the lower end of the body 38. A connecting nut 41 is provided on the outer side of the lower connector 39. The connecting nut 41 is connected to the lower connector 39, and a sealing ring 42 is provided between the two. The sealing tube 40 is disposed in the inner cavity of the lower connector 39, and the upper end of the sealing tube 40 is connected to the body 38.

[0076] It should be noted that the structure of the upper and lower connecting parts of the pressure-holding electric sampler is not limited to the structure in this embodiment, as long as it can satisfy the connection function between the upper and lower connecting devices of the sampler.

[0077] The pressure-holding electric sampler provided in this embodiment of the invention uses a pure electric power source. The sampling process is controlled by controlling the rotation of the motor. The transmission chain is purely mechanical, offering the technical advantages of low speed and high torque. Furthermore, the system is simplified and highly reliable. The sampler also features a biomimetic surface treatment on the inner wall of the liquid storage tube 36, ensuring that no components of the extracted liquid sample remain inside the storage tube 36, thereby ensuring the accuracy of the liquid sample component analysis data.

[0078] In this embodiment of the invention, the cable and mechanical parts of the pressure-holding electric sampler are arranged evenly on the plane according to a certain phase angle. The cable is positioned far away from the motor, thereby achieving the isolation effect between the cable and the motor. This ensures external isolation and no axial crossing, effectively reducing the interference of the motor's starting and stopping magnetic field on the cable transmission. It also avoids the device eccentricity problem caused by the heavier weight on one side of the drive component, sampling control component, and liquid storage component, ensuring the weight balance of the entire sampling device.

[0079] Based on the same inventive concept, this invention provides a method of using a pressure-holding electric sampler: after the control drive component is powered on, the drive valve core 28 and valve 31 move upward, opening the first liquid inlet channel 47 so that the sampling liquid enters the second liquid inlet channel 48. Under the action of liquid pressure, the ball bar 34 compresses the spring 35 and the valve seat 33 to create a gap, and the sampling liquid flows into the lower liquid storage tube 36 through the gap.

[0080] After sampling is completed, the valve core 28 and valve 31 are driven downward by controlling the movement of the drive component, closing the first liquid inlet channel 47. The ball rod 34 is reset under the action of the spring 35, and the ball rod 34 cooperates with the valve seat 33 to seal the liquid storage tank.

[0081] The specific usage method of this sampler is as follows:

[0082] After the sampler is lowered to the designated position in the well via cable, the sampling signal is transmitted to the circuit board 8 through the ground control system. The circuit board 8 controls the output shaft of the motor 10 to rotate. Due to the connection between the motor 10 and the lead screw 18, the rotation of the motor output shaft will transmit torque to the lead screw 18, causing the lead screw 18 to rotate. The rotation of the lead screw 18 causes the nut 20 to move upward, which in turn causes the transmission sleeve 22 to move upward. The upward movement of the transmission sleeve 22 causes the valve core 28 and the valve 31 to move upward, opening the first liquid inlet channel 47. The sampling liquid in the central channel 46 enters the second liquid inlet channel 48 through the first liquid inlet channel 47. The sampling liquid flows from the second liquid inlet channel 48 through the lowering ball bar 34, which compresses the spring 35. A gap is created between the ball bar 34 and the valve seat, and the sampling liquid flows into the lower storage pipe 36 through the gap.

[0083] When sampling stops, the ground control system transmits a stop sampling signal to the circuit board 8 in the circuit board frame 6. The circuit board 8 controls the output shaft of the motor 10 to rotate. Due to the connection between the motor 10 and the lead screw 18, the rotation of the motor output shaft will transmit torque to the lead screw 18, causing the lead screw 18 to rotate. At this time, the rotation of the lead screw 18 causes the nut 20 to move downward, which in turn causes the transmission sleeve to move downward. The downward movement of the transmission sleeve causes the valve core 28 and the valve 31 to move downward and close the first liquid inlet channel 47, so that the sampling liquid in the central channel 46 stops entering the first liquid inlet channel 47. The ball rod 34 is reset under the action of the spring 35. The sampling liquid is retained in the inner cavity of the liquid storage tube 36. The pressure of the sampling liquid in the liquid storage tube 36 acts on the ball rod 34 to ensure that the liquid storage tube 36 is always in a dynamic sealed balance state, maintaining the pressure of the liquid storage tube 36 unchanged, so as to maintain the pressure of the sampling liquid at the sampling formation.

[0084] This invention also provides an application of the above-mentioned pressure-holding electric sampler in a downhole sampling system.

[0085] An exemplary structure of a downhole sampling system is as follows: Figure 2 As shown, the downhole sampling system includes a surface control system 50 and a sampling tool string. The surface control system and the sampling tool string are connected by a logging vehicle cable. The sampling tool string includes, from top to bottom, a power module 51, a liquid mixing pump 52, an anchor 53, a first packer 54, the aforementioned pressure-holding electric sampler 55, a second packer 56, a magnetic positioning device 57, and a terminal section 58.

[0086] The sampling process of this downhole sampling system is as follows: First, the sampling tool string is lowered to a preset depth using a logging truck cable. The surface control system then controls the upper first packer and lower second packer of the sampler to set, while verifying successful and reliable setting. Upon reaching the designated position, the surface control system starts the drainage pump to extract fluid from the casing of the packer section. Formation fluid continuously enters the packer section until the fluid composition stabilizes. The surface control system then controls the sampler to start working, opening the first inlet channel, allowing fluid to flow into the storage tank. Once the storage tank is full, the surface control system controls the motor to close the first inlet channel, stopping the sampler's sampling. After sampling stops, the packers are unsealed, and the tool string is lifted. The storage tank remains sealed, maintaining the internal fluid composition and pressure. After the sampling tool string is brought to the surface, the storage tank is removed and properly stored for further processing by the laboratory analysis department.

[0087] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process may be rearranged without departing from the scope of this disclosure. The appended method claims provide elements of various steps in an exemplary order and are not intended to limit the scope to a specific order or hierarchy.

[0088] In the detailed description above, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features in a single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, with each claim representing a separate preferred embodiment of the invention.

[0089] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as interpreted when used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

Claims

1. A pressure-holding electric sampler, characterized in that, include: The main body assembly and the driving components, sampling control components and liquid storage components disposed within the cavity of the main body assembly; The main body component is provided with a central channel; The sampling control assembly includes a valve core and a valve; The driving component is connected to the valve core to drive the valve core to move up and down. The valve core is connected to the valve and drives the valve to move up and down to open or close the first liquid inlet channel on the body assembly for connecting the central channel. The liquid storage assembly includes a liquid storage tank, a ball rod disposed inside the liquid storage tank, and a spring nested on the ball rod; the liquid storage tank has a second liquid inlet channel communicating with the first liquid inlet channel; the ball rod compresses the spring and opens the second liquid inlet channel to allow liquid to enter the liquid storage tank under the liquid pressure from the first liquid inlet channel; and after sampling is completed, the second liquid inlet channel is closed under the restoring force of the spring. The first liquid inlet channel includes a first liquid inlet through hole and a second liquid inlet through hole; The first liquid inlet hole is connected to the central channel, and the end of the second liquid inlet hole connected to the first liquid inlet hole is a first conical hole. The lower end of the valve cooperates with the first conical hole to control the opening or closing of the first liquid inlet channel. The second liquid inlet channel includes a straight hole and a second conical hole. The ball end of the ball rod cooperates with the second conical hole to control the opening or closing of the second liquid inlet channel.

2. The sampler as described in claim 1, characterized in that, The liquid storage tank includes a valve seat, a liquid storage tube, and a plug; The valve seat, liquid storage pipe, and plug are sequentially and sealed together to form a liquid storage tank; The valve seat is mounted on the main body assembly, the valve seat is provided with the second liquid inlet channel, and the ball is mounted inside the liquid storage tube.

3. The sampler as described in claim 2, characterized in that, The liquid storage tube is provided with at least one liquid inlet hole, which connects the inner cavity of the liquid storage tube and the cavity formed by the valve seat and the liquid storage tube, so that the liquid that enters the cavity through the second liquid inlet channel enters the inner cavity of the liquid storage tube through the liquid inlet hole.

4. The sampler as described in claim 1, characterized in that, The main body assembly includes a circuit board frame, a first cylinder liner, a second cylinder liner, a valve body, a third cylinder liner, and the main body; The circuit board frame is sequentially connected to the valve body and the main body to form the central channel; The first cylinder liner is installed outside the circuit board frame, the second cylinder liner is installed outside the circuit board frame and the valve body, and the third cylinder liner is installed outside the valve body and the main body to form a main body assembly cavity; The first cylinder liner, the second cylinder liner, and the circuit board frame cooperate to form a drive component mounting cavity; the valve body, the third cylinder liner, and the main body cooperate to form the liquid storage component mounting cavity; the valve body is provided with a sampling component mounting hole.

5. The sampler as described in claim 4, characterized in that, The body assembly cavity is also provided with a cable channel for the cable to pass through the pressure-holding electric sampler; The cable is sealed to the circuit board frame and the main body via a sealing joint.

6. The sampler as described in claim 1, characterized in that, The drive component includes: a mounting bracket, a motor, a lead screw, a transmission sleeve, and a nut; The motor is fixed on the mounting bracket, the lead screw is mounted on the mounting bracket, the motor is connected to the lead screw to drive the lead screw to rotate, the lead screw drives the nut to move up and down, and the nut is connected to the transmission sleeve to drive the transmission sleeve to move up and down.

7. The sampler as described in claim 6, characterized in that, The transmission sleeve has an anti-rotation groove on its inner side, and an anti-rotation pin is installed in the anti-rotation groove.

8. The sampler as described in claim 6, characterized in that, The lower end of the transmission sleeve is provided with a threaded hole, and the lead screw is connected to the transmission sleeve by a thread.

9. The sampler as described in claim 7, characterized in that, The mounting bracket includes: a motor base, a bearing base, and a valve sleeve; The motor is fixed on the motor base, the bearing housing is disposed inside the motor base, and the valve sleeve is connected to the motor base and the valve body in sequence. The transmission sleeve is disposed in the inner cavity of the valve sleeve, and a sliding groove is opened on the inner wall of the valve sleeve. The anti-rotation pin passes through the transmission sleeve and slides up and down in the sliding groove under the action of the lead screw. The lead screw is disposed within the bearing housing, and two bearings are provided between the lead screw and the bearing housing.

10. The sampler as described in any one of claims 1-9, characterized in that, The sampler also includes an upper connecting part and a lower connecting part; The upper and lower connecting parts are respectively used to connect to the external packer of the sampler.

11. A method of using the pressure-holding electric sampler as described in any one of claims 1-10, characterized in that, include: After the control drive component is powered on, it drives the valve core and the valve to move upward, opening the first liquid inlet channel and allowing the sampled liquid to enter the second liquid inlet channel. Under the action of liquid pressure, the ball bar compresses the spring and the valve seat to create a gap, and the sampled liquid flows into the lower storage tank through the gap. After sampling is completed, the control drive component drives the valve core and valve to move downward, closing the first liquid inlet channel. The ball bar is reset under the action of the spring, and the ball bar cooperates with the valve seat to seal the liquid storage tank.

12. An application of a sampler as described in any one of claims 1-10 in a downhole sampling system.

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