High-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler

Abstract

This invention discloses a high-temperature, high-pressure self-contained deep well sampling device, belonging to the field of drilling engineering sampling technology. The sampling device includes an upper connector, a control outer pipe, an end cap, a valve body, and a storage chamber connected in sequence. An electromagnet is installed on the outside of the end cap, and an electrical control module is installed inside the control outer pipe. A valve core with a permanent magnet is slidably installed inside the valve body. The valve core is driven axially by the non-contact electromagnetic force between the electromagnet and the permanent magnet, realizing the opening and closing of the sampling channel. The bottom of the valve core has an internal channel connecting the sampling channel and the storage chamber, as well as a one-way valve. A sampling inlet channel is opened at the connection between the end cap and the valve body. This invention adopts a structure mainly based on pure mechanical seals, significantly improving the sealing reliability and operational stability under the high-temperature and high-pressure environment of deep wells. It does not rely on drilling fluid and achieves efficient, pressure-maintained sampling of in-situ formation fluids.

Description

Technical Field

[0001] This invention relates to sampling tools for drilling projects, and more specifically to a high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler. Background Technology

[0002] In-situ formation sampling technology plays a crucial role in oil and gas field exploration and development, serving as one of the most important methods for obtaining in-situ formation data. Its core requirements revolve around parameter acquisition and problem-solving in oil and gas field development. In oil and gas field exploration, as well depth increases, bottomhole temperature and pressure changes significantly. The state of the bottom fluid and the content of free oil and gas in the formation are critical for exploration. With the in-depth development of oil and gas resources such as deep wells and high-temperature, high-pressure condensate gas reservoirs, changes in downhole temperature and pressure easily lead to the analysis of heavy components. By taking gas-liquid mixture samples for analysis, accurate fluid composition and phase characteristics can be obtained, enabling the formulation of reasonable production systems and wax removal and prevention measures to ensure stable natural gas production. The analytical data of in-situ formation gas-liquid mixture samples are key evidence for oil and gas field development. By conducting high-pressure physical property experiments through sampling, condensate oil production can be determined, fluid phase characteristics can be studied, and support can be provided for optimizing drainage and production processes. Simultaneously, this data can also be used to study oilfield drive types, calculate oil and gas reserves, and help determine development methods and oil and gas well operating systems.

[0003] Pressure-holding samplers, as specialized devices capable of maintaining the original formation pressure of samples throughout the entire process of sampling, recovery, and subsequent processing, prevent changes in sample properties due to pressure variations. They are widely used in oil and gas field development, coal mine gas control, and offshore natural gas hydrate exploration. Domestically, with a focus on overcoming technical bottlenecks in specific working conditions, a diversified product system is gradually forming. In the coal mining sector, the high-pressure water-driven pressure-holding sampler can control coal seam exposure time to within 5 minutes when sampling from a 297-meter deep borehole, significantly reducing gas loss and providing more accurate test data than conventional sampling. In the oil and gas sector, the downhole full-bore annular pressure-operated pressure-holding sampler solves the problems of limited size and high leakage risk associated with traditional equipment, achieving a sampling capacity of up to 1200cc. In the deep-sea sector, Jilin University's bottom-hole cryogenic sampler and the China Geological Survey's TKP-1 insulated pressure-holding sampler have completed sea trials. Some of these devices utilize cryogenic technology or insulation materials to achieve heat and pressure preservation of natural gas hydrate samples.

[0004] However, most products are designed for specific scenarios and have poor cross-domain adaptability; their performance is limited under extreme conditions, such as the success rate of samplers dropping significantly when the temperature exceeds 150°C. Most samplers also suffer from high maintenance costs and cumbersome operation procedures, making it difficult to promote and apply them on a large scale.

[0005] The structural design, which primarily uses a mechanical seal and supplements it with a high-temperature resistant O-ring, effectively improves the sealing performance of the sampler under high-temperature conditions. The non-contact, electrically driven switch valve core structure, through a time-delay control method, enables autonomous and rapid in-situ formation sampling in deep wells. It is independent of drilling fluid and is more stable and reliable than traditional ball-drop or differential control switching methods. It has good application prospects in deep oil and gas well drilling and sampling, hydrate drilling and sampling, and in-situ formation sampling in drilling and completion engineering. Summary of the Invention

[0006] In view of this, the present invention provides a high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler, which aims to solve the above-mentioned technical problems.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler includes: an upper connector, a control outer tube, an end cap, a valve body, and a liquid storage chamber connected in sequence;

[0009] The flange of the end cap is fastened between the end face of the control outer tube and the valve body by bolts, so that the end cap is coaxially sleeved inside the control outer tube. An electromagnet is nested on the outer wall of the end of the end cap away from the valve body. An electronic control module for controlling the electromagnet to be energized is provided inside the control outer tube.

[0010] A valve core is slidably connected to the valve body. A sampling channel is formed between the outer wall of the valve core and the inner wall of the valve body. The valve core has an end section that extends into the inner side of the end cap. A permanent magnet is fixed to the end of the end section. The electromagnet can exert force with the permanent magnet, thereby enabling the valve core to perform axial reciprocating motion within the valve body to satisfy the opening and closing of the sampling channel. An internal channel is opened at the bottom of the valve core, which communicates with the sampling channel and the liquid storage chamber. A one-way valve is installed at one end of the internal channel that communicates with the liquid storage chamber.

[0011] A sampling inlet channel, which communicates with the sampling flow channel, is provided at the connection between the end cap and the valve body.

[0012] Through the above technical solution, the present invention achieves rapid and reliable control of the sampling channel opening and closing under the high temperature and high pressure environment of deep wells by adopting a non-contact drive valve core structure of electromagnet and permanent magnet. The design is based on pure mechanical seal, which significantly improves the sealing performance and operational stability of the sampler under extreme working conditions, and does not rely on drilling fluid. It is suitable for pressure-maintaining sampling operations in deep oil and gas wells, hydrates and other in-situ formations.

[0013] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, the valve core includes a first straight segment, a first conical segment, a second straight segment, a second conical segment, a third straight segment, and a fourth straight segment that are sequentially connected to the end section and whose outer diameters increase sequentially.

[0014] The valve body has a first straight hole corresponding to the first straight segment, a first conical hole corresponding to the first conical segment, a second straight hole corresponding to the second straight segment, a second conical hole corresponding to the second conical segment, and a third straight hole corresponding to the third straight segment and the fourth straight segment.

[0015] The first straight segment slides into the first straight hole, the second straight segment has a clearance fit with the second straight hole to form a first liquid inlet cavity, the third straight segment has a clearance fit with the third straight hole to form a second liquid inlet cavity, and the fourth straight segment slides into the third straight hole.

[0016] The second liquid inlet chamber is connected to the inner channel of the valve core, and the sampling inlet channel is connected to the first liquid inlet chamber.

[0017] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well sampler, when the permanent magnet on the valve core is attracted by the electromagnet, the second conical section and the second conical hole close together and disconnect the sampling channel; when the permanent magnet on the valve core is repelled by the electromagnet, the second conical section and the second conical hole separate and open the sampling channel.

[0018] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, a first O-ring is provided between the first straight segment and the first straight hole, and a second O-ring is provided between the fourth straight segment and the third straight hole.

[0019] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, a limiting cylinder is fixedly sleeved on the inner side of the end cap, and the limiting cylinder is used to limit the axial movement of the permanent magnet when it is subjected to repulsive force; the bottom end of the valve core has a bottom limiting section with an outer diameter larger than that of the fourth straight segment, and the bottom limiting section is used to limit the axial movement of the permanent magnet when it is subjected to attractive force.

[0020] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, a retaining ring is threadedly connected to the end section, the retaining ring is located at the end of the permanent magnet away from the electromagnet, and a return spring is sleeved on the end section, the return spring being pressed between the retaining ring and the end face of the valve body.

[0021] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well sampler, the portion of the sampling inlet channel located in the valve body is equipped with a filter screen.

[0022] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, the outlet of the valve core inner channel has an enlarged diameter port, the one-way valve includes a nut threadedly connected to the enlarged diameter port, the nut has a drain port, the through hole in the center of the nut is slidably connected to a valve stem, the end of the valve stem has a ball head for sealing the valve core inner channel, and a valve control spring is sleeved on the valve stem, the valve control spring being pressed between the ball head and the nut.

[0023] Preferably, in the above-mentioned high-temperature and high-pressure self-contained deep well pressure-maintaining sampler, the liquid storage chamber is threadedly connected to the valve body, and a safety valve and a transfer valve are connected to the bottom of the liquid storage chamber.

[0024] Preferably, in the above-mentioned high-temperature and high-pressure autonomous deep well pressure-maintaining sampler, the electrical control module includes a time delay control unit electrically connected to the electromagnet and a battery pack for power supply.

[0025] As can be seen from the above technical solution, compared with the prior art, the present invention discloses a high-temperature and high-pressure self-contained deep well pressure-holding sampler. Its structural design, primarily using a pure mechanical seal and supplemented by a high-temperature O-ring seal, effectively improves the sampler's sealing performance under high-temperature conditions. Employing a sealed, non-contact, electrically driven switch valve core structure, it can quickly and reliably open or close the valve by delaying the gain or loss of power to the electromagnet, enabling the collection of in-situ formation samples from deep wells. This method is independent of drilling fluid and is more stable and reliable than traditional ball-dropping or differential control switching methods. It provides a new technical solution for deep oil and gas well drilling and sampling, hydrate drilling and sampling, and in-situ formation sampling in drilling and completion engineering. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0027] Figure 1 The attached figure is a structural schematic diagram of the high-temperature and high-pressure self-contained deep well pressure-maintaining sampler provided by the present invention;

[0028] Figure 2 The attached figure is a schematic diagram of the valve body, end cap, and valve core assembly provided by the present invention.

[0029] Figure 3The attached figure is provided by the present invention. Figure 2 A magnified view of part A in the middle;

[0030] Figure 4 The attached figure is a schematic diagram of the closed state of the high temperature and high pressure resistant autonomous deep well pressure-maintaining sampler provided by the present invention;

[0031] Figure 5 The attached figure is a schematic diagram of the open state of the high temperature and high pressure resistant autonomous deep well pressure-maintaining sampler provided by the present invention.

[0032] in:

[0033] 01-Upper connector;

[0034] 02-Control outer pipe;

[0035] 03-End cap; 031-Flange; 032-Electromagnet; 033-Limiting cylinder;

[0036] 04-Valve body; 041-First straight hole; 042-First tapered hole; 043-Second straight hole; 044-Second tapered hole; 045-Third straight hole;

[0037] 05-Liquid storage chamber; 051-Safety valve; 052-Transfer valve;

[0038] 06- Bolt;

[0039] 07-Electronic control module; 071-Delay control unit; 072-Battery pack;

[0040] 08-Valve core; 081-End section; 082-Permanent magnet; 083-Inner channel of valve core; 084-First straight section; 085-First conical section; 086-Second straight section; 087-Second conical section; 088-Third straight section; 089-Fourth straight section; 0810-Bottom limiting section; 0811-Retaining ring; 0812-Return spring; 0813-Expanded diameter port;

[0041] 09-Sampling channel; 091-First inlet chamber; 092-Second inlet chamber;

[0042] 10-Check valve; 101-Nut; 1011-Drain port; 102-Valve stem; 103-Ball head; 104-Valve control spring;

[0043] 11-Sampling inlet channel; 111-Filter screen;

[0044] 12 - First O-ring seal;

[0045] 13 - Second O-ring seal. Detailed Implementation

[0046] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0047] See appendix Figure 1 and attached Figure 2 This invention discloses a high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler, comprising: an upper connector 01, a control outer pipe 02, an end cap 03, a valve body 04, and a liquid storage chamber 05 connected in sequence;

[0048] The flange 031 of the end cover 03 is fastened between the end face of the control outer tube 02 and the valve body 04 by bolts 06, so that the end cover 03 is coaxially sleeved on the inner side of the control outer tube 02. An electromagnet 032 is nested on the outer wall of the end of the end cover 03 away from the valve body 04. An electrical control module 07 for controlling the electromagnet 032 to be energized is provided inside the control outer tube 02.

[0049] A valve core 08 is slidably connected inside the valve body 04. A sampling channel 09 is formed between the outer wall of the valve core 08 and the inner wall of the valve body 04. The valve core 08 has an end section 081 that extends into the inner side of the end cap 03. A permanent magnet 082 is fixed at the end of the end section 081. An electromagnet 032 can exert force with the permanent magnet 082, thereby enabling the valve core 08 to perform axial reciprocating motion within the valve body 04 to satisfy the opening and closing of the sampling channel 09. The bottom of the valve core 08 has an inner channel 083 that communicates with the sampling channel 09 and the liquid storage chamber 05. A one-way valve 10 is installed at one end of the inner channel 083 that communicates with the liquid storage chamber 05.

[0050] A sampling inlet channel 11, which is connected to the sampling flow channel 09, is provided at the connection between the end cap 03 and the valve body 04.

[0051] To further optimize the above technical solution, the valve core 08 includes a first straight segment 084, a first tapered segment 085, a second straight segment 086, a second tapered segment 087, a third straight segment 088, and a fourth straight segment 089, which are connected in sequence to the end segment 081 and have increasing outer diameters in sequence.

[0052] The valve body 04 has a first straight hole 041 corresponding to the first straight segment 084, a first conical hole 042 corresponding to the first conical segment 085, a second straight hole 043 corresponding to the second straight segment 086, a second conical hole 044 corresponding to the second conical segment 087, and a third straight hole 045 corresponding to the third straight segment 088 and the fourth straight segment 089.

[0053] The first straight segment 084 is slidably fitted with the first straight hole 041, the second straight segment 086 is clearance fitted with the second straight hole 043 to form the first liquid inlet chamber 091, the third straight segment 088 is clearance fitted with the third straight hole 045 to form the second liquid inlet chamber 092, and the fourth straight segment 089 is slidably fitted with the third straight hole 045.

[0054] The second liquid inlet chamber 092 is connected to the valve core inner channel 083, and the sampling inlet channel 11 is connected to the first liquid inlet chamber 091.

[0055] To further optimize the above technical solution, when the permanent magnet 082 on the valve core 08 is attracted by the electromagnet 032, the second conical section 087 and the second conical hole 044 come into contact and disconnect the sampling channel 09; when the permanent magnet 082 on the valve core 08 is repelled by the electromagnet 032, the second conical section 087 and the second conical hole 044 separate and open the sampling channel 09.

[0056] To further optimize the above technical solution, a first O-ring 12 is provided between the first straight segment 084 and the first straight hole 041, and a second O-ring 13 is provided between the fourth straight segment 089 and the third straight hole 045.

[0057] To further optimize the above technical solution, a limiting cylinder 033 is fixedly sleeved on the inner side of the end cap 03. The limiting cylinder 033 is used to restrict the axial movement of the permanent magnet 082 when it is subjected to repulsive force. The bottom end of the valve core 08 has a bottom limiting section 0810 with an outer diameter larger than that of the fourth straight segment 089. The bottom limiting section 0810 is used to restrict the axial movement of the permanent magnet 082 when it is subjected to attractive force. When the liquid storage chamber 05 contains a high-pressure gas-liquid mixture, it will tightly press against the lower end face of the valve core 08 and the one-way valve 10 to ensure internal sealing.

[0058] To further optimize the above technical solution, a retaining ring 0811 is threaded onto the end section 081. The retaining ring 0811 is located at the end of the permanent magnet 082 away from the electromagnet 032, and a return spring 0812 is sleeved on the end section 081. The return spring 0812 is pressed between the retaining ring 0811 and the end face of the valve body 04.

[0059] To further optimize the above technical solution, a filter screen 111 is provided in the part of the sampling inlet channel 11 located in the valve body 04.

[0060] See appendix Figure 3The outlet of the valve core inner channel 083 has an enlarged diameter port 0813. The one-way valve 10 includes a nut 101 threadedly connected to the enlarged diameter port 0813. A drain port 1011 is provided on the nut 101. A valve stem 102 is slidably connected to the through hole in the center of the nut 101. The end of the valve stem 102 has a ball head 103 for blocking the valve core inner channel 083. A valve control spring 104 is sleeved on the valve stem 102. The valve control spring 104 is pressed between the ball head 103 and the nut 101.

[0061] To further optimize the above technical solution, the liquid storage chamber 05 is threadedly connected to the valve body 04, and a safety valve 051 and a transfer valve 052 are connected to the bottom of the liquid storage chamber 05. The safety valve 051 will automatically release pressure to ensure safety when the internal pressure is too high; the transfer valve 052 is used when evacuating the liquid storage chamber 05 and transferring samples.

[0062] To further optimize the above technical solution, the electronic control module 07 includes a time-delay control unit 071 electrically connected to the electromagnet 032 and a battery pack 072 for power supply. The time-delay control unit 071 includes two sets of relays with time settings, which control the relays to turn on and off at different times, thereby controlling the energization of the electromagnet 032. During well operations, the time-delay control unit 071 includes two sets of relays with time settings, which control the relays to be energized with a delay, thereby controlling the energization of the electromagnet 032.

[0063] Electromagnetic force is generated between electromagnet 032 and permanent magnet 082, thereby driving valve core 08 to move;

[0064] After a period of time, the delay control unit 071 controls the relay to be energized in reverse, thereby controlling the electromagnet 032 to be energized in reverse.

[0065] Electromagnet 032 and permanent magnet 082 will generate a reverse electromagnetic force, which together with the return spring 0812 will drive valve core 08 back to its original position;

[0066] In this embodiment, the upper connector 01 and the control outer tube 02 are connected by a threaded seal. The upper connector 01 has a threaded and fixed ring structure. During operation, the sampler can be lowered independently by connecting the fixed ring to the wire rope or lowered after being connected to other tools.

[0067] In this embodiment, the valve core 08, end cap 03, valve body 04, control outer tube 02, retaining ring 0811, and limiting cylinder 033 are made of non-magnetic steel.

[0068] The working method of the high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler provided in this embodiment includes the following steps:

[0069] Step 1: Based on the working well depth, pre-set the working time of the delay control unit 071 and ensure that the two sets of relays have sufficient control interval time;

[0070] Step 2: Based on the working conditions, set the required vibration frequency and working time, then disconnect the host computer and seal the communication port to prepare for operation;

[0071] Step 3: Complete the assembly of valve body 04 and valve core 08, energize electromagnet 032, and test whether valve core 08 moves normally; complete the assembly of liquid storage chamber 05, upper connector 01 and electrical control module 07.

[0072] Step 4: Start the sampling operation. Depending on the well depth, use the delay control unit 071 to control the valve core 08 to open at different times to complete the sample collection. After waiting for a fixed time, retrieve the sampler.

[0073] Step 5: Remove the sampler control unit and complete sample collection in accordance with relevant technical requirements;

[0074] Step 6: Check and replace the battery pack as needed based on usage, clean and check the tools, reassemble, and wait for the next operation.

[0075] The working principle of this embodiment is as follows: the initial closed state is as follows: Figure 4 As shown, when opened, the delay control unit 071 controls the electromagnet 032 to be energized after a delay, generating an electromagnetic force between it and the permanent magnet 082 on the valve core 08. This pushes the valve core 08 to open the conical seal formed by the second conical section 087 and the second conical hole 044. Liquid enters the storage chamber 05 through the first inlet chamber 091, the second inlet chamber 092, and the valve core inner channel 083 via the one-way valve 10. After a period of time, the delay control unit 071 controls the electromagnet 032 to be energized in the reverse direction. The return spring 0812 and the electromagnetic force jointly push the valve core 08 to close the channel. The liquid in the storage chamber 05 is sealed by the conical surface, achieving pressure-holding sample collection. When the sampler is retrieved, because the pressure in the storage chamber 05 is higher than the external pressure, it will continuously press against the conical surface, ensuring that the internal liquid or gas will not leak. Figure 4 As shown; pre-vacuuming of the liquid storage chamber 05 can avoid air pollution and further increase the liquid inlet speed.

[0076] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to the method section.

[0077] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high-temperature and high-pressure resistant autonomous deep-well pressure-maintained sampler, characterized in that, include: The upper connector (01), control outer tube (02), end cap (03), valve body (04) and liquid storage chamber (05) are connected in sequence. The flange (031) of the end cap (03) is fastened between the end face of the control outer tube (02) and the valve body (04) by bolts (06), so that the end cap (03) is coaxially sleeved inside the control outer tube (02), and an electromagnet (032) is nested on the outer wall of the end of the end cap (03) away from the valve body (04); an electrical control module (07) for controlling the electromagnet (032) to be energized is provided inside the control outer tube (02). A valve core (08) is slidably connected inside the valve body (04). A sampling channel (09) is formed between the outer wall of the valve core (08) and the inner wall of the valve body (04). The valve core (08) has an end section (081) that extends into the inner side of the end cap (03). A permanent magnet (082) is fixed at the end of the end section (081). The electromagnet (032) can exert force with the permanent magnet (082), thereby enabling the valve core (08) to perform axial reciprocating motion inside the valve body (04) to satisfy the opening and closing of the sampling channel (09). A valve core inner channel (083) is opened at the bottom of the valve core (08) and communicates with the sampling channel (09) and the liquid storage chamber (05). A one-way valve (10) is installed at one end of the valve core inner channel (083) that communicates with the liquid storage chamber (05). The end cap (03) and the valve body (04) are connected by a sampling inlet channel (11) that communicates with the sampling channel (09). The valve core (08) includes a first straight segment (084), a first tapered segment (085), a second straight segment (086), a second tapered segment (087), a third straight segment (088), and a fourth straight segment (089) that are sequentially connected to the end segment (081) and have progressively increasing outer diameters. The valve body (04) has a first straight hole (041) corresponding to the first straight segment (084), a first conical hole (042) corresponding to the first conical segment (085), a second straight hole (043) corresponding to the second straight segment (086), a second conical hole (044) corresponding to the second conical segment (087), and a third straight hole (045) corresponding to the third straight segment (088) and the fourth straight segment (089). The first straight segment (084) is slidably fitted with the first straight hole (041), the second straight segment (086) is clearance fitted with the second straight hole (043) to form a first liquid inlet chamber (091), the third straight segment (088) is clearance fitted with the third straight hole (045) to form a second liquid inlet chamber (092), and the fourth straight segment (089) is slidably fitted with the third straight hole (045). The second liquid inlet chamber (092) is connected to the valve core inner channel (083), and the sampling inlet channel (11) is connected to the first liquid inlet chamber (091); A first O-ring (12) is provided between the first straight segment (084) and the first straight hole (041), and a second O-ring (13) is provided between the fourth straight segment (089) and the third straight hole (045). A limiting sleeve (033) is fixedly sleeved on the inner side of the end cap (03). The limiting sleeve (033) is used to limit the axial movement of the permanent magnet (082) when it is subjected to repulsive force. The bottom end of the valve core (08) has a bottom limiting section (0810) with an outer diameter larger than that of the fourth straight segment (089). The bottom limiting section (0810) is used to limit the axial movement of the permanent magnet (082) when it is subjected to attractive force. A retaining ring (0811) is threaded onto the end section (081). The retaining ring (0811) is located at the end of the permanent magnet (082) away from the electromagnet (032). A return spring (0812) is sleeved on the end section (081). The return spring (0812) is pressed against the end face of the retaining ring (0811) and the valve body (04). The liquid storage chamber (05) is threadedly connected to the valve body (04), and a safety valve (051) and a transfer valve (052) are connected to the bottom of the liquid storage chamber (05).

2. The high temperature and high pressure resistant autonomous deep well pressure-maintaining sampler according to claim 1, characterized in that, When the permanent magnet (082) on the valve core (08) is attracted by the electromagnet (032), the second conical segment (087) and the second conical hole (044) come into contact and disconnect the sampling channel (09); when the permanent magnet (082) on the valve core (08) is repelled by the electromagnet (032), the second conical segment (087) and the second conical hole (044) separate and open the sampling channel (09).

3. The high-temperature and high-pressure resistant autonomous deep-well pressure-maintaining sampler according to claim 1, characterized in that, The sampling inlet channel (11) located in the valve body (04) is equipped with a filter screen (111).

4. The high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler according to claim 1, characterized in that, The outlet of the valve core inner channel (083) has an enlarged diameter port (0813). The one-way valve (10) includes a nut (101) threadedly connected to the enlarged diameter port (0813). A drain port (1011) is provided on the nut (101). A valve stem (102) is slidably connected to the through hole in the center of the nut (101). The end of the valve stem (102) has a ball head (103) for blocking the valve core inner channel (083). A valve control spring (104) is sleeved on the valve stem (102). The valve control spring (104) is pressed between the ball head (103) and the nut (101).

5. The high-temperature and high-pressure resistant autonomous deep well pressure-maintaining sampler according to claim 1, characterized in that, The electronic control module (07) includes a delay control unit (071) electrically connected to the electromagnet (032) and a battery pack (072) for power supply.

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