Fluid control valve and geothermal well multilayer mining pipe column

Abstract

The invention belongs to the technical field of geothermal development, and particularly relates to a fluid control valve and a geothermal well multilayer mining pipe column. The fluid control valve comprises a fixing sleeve; the sleeve is coaxially arranged on the outer side of the fixing sleeve, a first liquid inlet channel, a second liquid inlet channel and a third liquid inlet channel are sequentially arranged between the fixing sleeve and the sleeve in the axial direction, and a cavity is formed between the fixing sleeve and the sleeve; the sliding short section is movably arranged in the cavity, in the first state, the sliding short section blocks the second liquid inlet channel, and in the second state, the sliding short section blocks the third liquid inlet channel; the outer cylinder sleeve is coaxially arranged on the outer side of the sleeve, a first sealing piece and a second sealing piece are arranged between the outer cylinder sleeve and the sleeve, the first sealing piece is located between the first liquid inlet channel and the second liquid inlet channel, and the second sealing piece is located between the second liquid inlet channel and the third liquid inlet channel; and a liquid inlet is formed between the first sealing piece and the second sealing piece on the side wall of the outer cylinder sleeve.

Description

Technical Field

[0001] This invention belongs to the field of geothermal development technology, specifically relating to a fluid control valve and a multi-layer extraction tubing for geothermal wells. Background Technology

[0002] Geothermal energy, as a green energy source, has broad market prospects for its exploitation and utilization. By employing a layered extraction process, multiple heat sources can be extracted from a single wellbore within a multi-layered geothermal reservoir, meeting the future needs for refined geothermal development and improving geothermal utilization efficiency.

[0003] Fluid control valves are critical tools for stratified extraction. Existing fluid control valves typically include mechanical and electro-hydraulic types. Mechanical fluid control valves usually use wirelines to switch them, but wireline operations are difficult to perform on / off operations on mechanical fluid control valves in geothermal wells. Existing electro-hydraulic fluid control valves are too expensive. Furthermore, scale and gravel in geothermal reservoirs easily adhere to the inner surface of fluid control valves, potentially leading to wear and malfunctions after prolonged use.

[0004] Chinese patent document CN209470380U discloses a hydrothermal multi-layer geothermal well production and injection device. This device connects multiple geothermal reservoirs via a two-stage casing. One portion of these reservoirs serves as the primary reservoir, while the other serves as a backup reservoir. A retrievable bridge plug separates the primary and backup reservoirs. During winter heating, the primary reservoir provides heat. In extremely cold weather, when the primary reservoir's heat supply is insufficient, the retrievable bridge plug is opened to activate the backup reservoir, providing simultaneous heating. This allows for flexible winter heating capacity without relying on heat pumps for peak shaving. However, the installation and retrieval of the retrievable bridge plug are complex and costly. Therefore, to meet the needs of multiple-layer extraction, it is necessary to design a low-cost layer-switching production string to support the layered extraction of geothermal wells.

[0005] Chinese patent document CN102650204A discloses a hydraulically controlled single-flow valve for use in the extraction of heavy oil and extra-heavy oil, but its functionality is limited in the multi-layer extraction of geothermal water.

[0006] Therefore, there is a need to seek more economical and reasonable fluid control valves. Summary of the Invention

[0007] In view of the technical problems described above, the present invention aims to provide a fluid control valve that can solve at least one of the aforementioned technical problems.

[0008] The present invention also proposes a multi-layer production tubing for geothermal wells, which includes the fluid control valve proposed in the present invention, and can solve at least one of the above-mentioned technical problems.

[0009] According to the present invention, a fluid control valve is provided, comprising:

[0010] Fixing sleeve;

[0011] A sleeve is coaxially disposed on the outside of the fixed sleeve. A first liquid inlet channel, a second liquid inlet channel and a third liquid inlet channel are sequentially arranged along the axial direction between the fixed sleeve and the sleeve. A cavity is provided between the fixed sleeve and the sleeve.

[0012] A movable sliding section is disposed within the cavity. In a first state, the sliding section blocks the second liquid inlet channel; in a second state, the sliding section blocks the third liquid inlet channel.

[0013] An outer cylinder sleeve is coaxially disposed on the outside of the sleeve. A first seal and a second seal are disposed between the outer cylinder sleeve and the sleeve. The first seal is located between the first liquid inlet channel and the second liquid inlet channel, and the second seal is located between the second liquid inlet channel and the third liquid inlet channel. A liquid inlet is disposed on the side wall of the outer cylinder sleeve between the first seal and the second seal.

[0014] In one specific embodiment, the sliding section is configured to switch between the first state and the second state under pressure.

[0015] In one specific embodiment, a pressure-transmitting hole is provided on the side wall of the sliding section, the pressure-transmitting hole is connected to the first liquid inlet channel, and the upper and lower surfaces of the pressure-transmitting hole are constructed as differential pressure surfaces.

[0016] In one specific embodiment, an upper short section is provided between the sleeve and the fixed sleeve, a switch spring is provided between the upper short section and the sliding short section, a switch groove is provided on the outer wall of the fixed sleeve, the switch groove includes a first groove and a second groove with different axial lengths, a switch pin is provided on the sliding short section for fitting with the switch groove, the sliding short section is configured to rotate relative to the fixed sleeve, and the switch pin switches between the first groove and the second groove, thereby switching the sliding short section between the first state and the second state.

[0017] In one specific embodiment, a switching groove is provided on the outer wall of the fixed sleeve. The switching groove is located above the switch groove. When the sliding section moves upward to contact the switching groove, the sliding section can rotate to switch between the first groove and the second groove.

[0018] In one specific embodiment, a one-way valve is provided inside the fixed sleeve, the one-way valve being configured to allow fluid to flow unidirectionally from the second inlet channel to the first inlet channel.

[0019] In one specific embodiment, the one-way valve includes:

[0020] A valve seat is disposed on the inner side of the fixed sleeve, and the valve seat is located between the first liquid inlet channel and the second liquid inlet channel;

[0021] An axially movable switch valve body is disposed within the fixed sleeve for fitting with the valve seat, the switch valve body being located above the valve seat;

[0022] A reset spring is disposed between the upper section and the switch valve body.

[0023] In one specific embodiment, the one-way valve further includes:

[0024] A support sleeve is installed inside the fixed sleeve;

[0025] A switch shaft is movably disposed within the support sleeve. The lower end of the switch shaft is connected to the switch valve body, and the upper end of the switch shaft is provided with a limiting section, which is located above the support sleeve.

[0026] In one specific embodiment, a screen is provided at the liquid inlet.

[0027] According to the present invention, a multi-layer production tubing string for a geothermal well is also provided, wherein the geothermal well includes a production casing that passes through a second reservoir and a third reservoir sequentially from top to bottom;

[0028] The fluid control valve provided by the present invention has its upper and lower sides respectively disposed in the production casing through a first packer and a second packer, and the second reservoir and the second liquid inlet channel of the fluid control valve are located between the first packer and the second packer.

[0029] In one specific embodiment, a first reservoir is provided above the first packer, and a central tube is provided at the upper end of the fluid control valve provided by the present invention.

[0030] Compared with the prior art, the advantages of this application are as follows.

[0031] The fluid control valve provided by this invention can switch between a first state and a second state under the pressure of the fluid in the well, thereby realizing the switching exploitation of a second or third reservoir. Compared with the fluid control valves in the prior art that switch via steel wire, it is simple to operate and can quickly complete the switching between different reservoirs.

[0032] The inlet of this invention is equipped with a screen, which can prevent scale or grit from entering the fluid control valve, thereby reducing the wear of internal parts during sliding and extending the service life of the fluid control valve.

[0033] This invention enables the extraction of geothermal water from three geothermal reservoirs by using a hydraulically controlled fluid control valve in conjunction with two packers. Attached Figure Description

[0034] The present invention will now be described with reference to the accompanying drawings.

[0035] Figure 1 A schematic diagram showing a second state of an embodiment of the fluid control valve according to the present invention is displayed;

[0036] Figure 2 A schematic diagram showing a first state of an embodiment of the fluid control valve according to the present invention is displayed;

[0037] Figure 3 A schematic diagram of the external structure of a fixing sleeve according to an embodiment of the present invention is shown;

[0038] Figure 4 A schematic diagram of a first embodiment of a multi-layer geothermal well production string according to the present invention is shown.

[0039] Figure 5 A schematic diagram of a second embodiment of a multi-layered geothermal well production string according to the present invention is shown.

[0040] In the picture:

[0041] 1. Fixing sleeve; 11. Lower short section;

[0042] 2. Sleeve; 20. Cavity; 21. First liquid inlet channel; 211. First through hole; 212. Second through hole; 22. Second liquid inlet channel; 221. Third through hole; 222. Fourth through hole; 223. Fifth through hole; 23. Third liquid inlet channel; 231. Sixth through hole; 232. Seventh through hole;

[0043] 3. Sliding sub; 31. Pressure transmission hole; 32. Upper sub; 33. Switch spring; 34. Switch slot; 341. First slot; 342. Second slot; 35. Switch pin; 36. Switching slot; 37. Center post;

[0044] 4. Outer cylinder liner; 401. First seal; 402. Second seal; 40. Liquid inlet; 42. Upper connector; 43. Lower connector; 44. Cylinder body;

[0045] 5. Check valve; 51. Valve seat; 52. Switch valve body; 53. Return spring; 54. Support sleeve; 55. Switch shaft; 56. Limit section;

[0046] 61. First ring empty; 62. Second ring empty;

[0047] 101. First reservoir; 102. Second reservoir; 103. Third reservoir; 104. First packer; 105. Production casing; 106. Second packer; 107. Center tube; 108. Wellhead assembly; 109. Submersible pump; 110. Annulus;

[0048] 100. Fluid control valve.

[0049] In this application, all drawings are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

[0050] The invention will now be described with reference to the accompanying drawings.

[0051] It should be noted that the directional terms or qualifiers such as "up" and "down" used in this application are all specific to the referenced [reference]. Figure 1 In other words, they are not used to define the absolute position of the components involved, but can vary depending on the specific circumstances.

[0052] Example 1

[0053] Figure 1 A schematic diagram showing a second state of an embodiment of the fluid control valve according to the present invention is displayed; Figure 2 A schematic diagram showing a first state of an embodiment of the fluid control valve according to the present invention is displayed; Figure 3 A schematic diagram of the external structure of a fixing sleeve according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of a first embodiment of a multi-layer geothermal well production string according to the present invention is shown. Figure 5 A schematic diagram of a second embodiment of a multi-layered geothermal well production string according to the present invention is shown.

[0054] like Figure 1 and Figure 2 As shown, the fluid control valve 100 mainly includes a fixed sleeve 1, a sleeve 2, a sliding short section 3, and an outer cylinder sleeve 4. The fixed sleeve 1, sleeve 2, sliding short section 3, and outer cylinder sleeve 4 are all constructed in a roughly cylindrical shape, and the fixed sleeve 1, sliding short section 3, sleeve 2, and outer cylinder sleeve 4 are coaxially sleeved from the inside to the outside.

[0055] According to the present invention, the sleeve 2 is coaxially disposed on the outside of the fixed sleeve 1, and a cavity 20 is provided between the fixed sleeve 1 and the sleeve 2.

[0056] Both the upper and lower ends of the sleeve 2 and the fixed sleeve 1 are closed. Specifically, in this embodiment, the sleeve 2 is coaxially spaced and fitted onto the outside of the fixed sleeve 1. An upper short section 32 is fixedly provided at the upper end of the sleeve 2 and the fixed sleeve 1. The upper short section 32 seals the upper end of the cavity 20 between the fixed sleeve 1 and the sleeve 2 on the one hand, and seals the upper port of the fixed sleeve 1 on the other hand. The lower end of the sleeve 2 is sealed with the lower end of the fixed sleeve 1, thereby sealing the lower end of the cavity 20. A lower short section 11 is provided at the lower end of the sleeve 2, and the lower short section 11 seals the lower end of the sleeve 2.

[0057] A first liquid inlet channel 21, a second liquid inlet channel 22 and a third liquid inlet channel 23 are sequentially arranged axially between the fixed sleeve 1 and the sleeve 2.

[0058] The first liquid inlet channel 21 includes a first through hole 211 on the side wall of the fixed sleeve 1 and a second through hole 212 on the side wall of the sleeve 2. Fluid inside the fixed sleeve 1 can flow to the outside of the sleeve 2 through the first through hole 211 and the second through hole 212 in sequence.

[0059] The second liquid inlet channel 22 includes a third through hole 221 provided on the side wall of the fixed sleeve 1 and a fourth through hole 222 provided on the side wall of the sleeve 2. Fluid outside the sleeve 2 can flow into the interior of the fixed sleeve 1 through the fourth through hole 222 and the third through hole 221 in sequence.

[0060] The third liquid inlet channel 23 includes a sixth through hole 231 provided on the side wall of the fixed sleeve 1 and a seventh through hole 232 provided on the side wall of the sleeve 2. Fluid outside the sleeve 2 can flow into the interior of the fixed sleeve 1 through the seventh through hole 232 and the sixth through hole 231 in sequence.

[0061] The sliding short section 3 is movably disposed within the cavity 20. That is, the sliding short section 3 can move axially relative to the fixed sleeve 1 and the sleeve 2. In the first state, as... Figure 2 As shown, the first liquid inlet channel 21 and the third liquid inlet channel 23 are in the open state, and the sliding section 3 blocks the second liquid inlet channel 22. In the second state, as... Figure 1 As shown, the first liquid inlet channel 21 and the second liquid inlet channel 22 are in the open state, and the sliding short section 3 blocks the third liquid inlet channel 23.

[0062] Specifically, a pressure-transmitting hole 31 and a fifth through hole 223 are provided on the side wall of the sliding sub-section 3, with the pressure-transmitting hole 31 located above the fifth through hole 223. In the first state, the sliding sub-section 3 moves downwards, as... Figure 2As shown, the pressure-transmitting hole 31 of the sliding section 3 connects the first through hole 211 of the fixed sleeve 1 and the second through hole 212 of the sleeve 2, thereby opening the first liquid inlet channel 21. The fifth through hole 223 of the sliding section 3 connects the sixth through hole 231 of the fixed sleeve 1 and the seventh through hole 232 of the sleeve 2, thereby opening the third liquid inlet channel 23. The sliding section 3 separates the third through hole 221 of the fixed sleeve 1 and the fourth through hole 222 of the sleeve 2, thereby sealing the second liquid inlet channel 22.

[0063] In the second state, the sliding section 3 moves upward, as follows: Figure 1 As shown, the pressure-transmitting hole 31 of the sliding section 3 connects the first through hole 211 of the fixed sleeve 1 and the second through hole 212 of the sleeve 2, thereby opening the first liquid inlet channel 21. The fifth through hole 223 of the sliding section 3 connects the third through hole 221 of the fixed sleeve 1 and the fourth through hole 222 of the sleeve 2, thereby opening the second liquid inlet channel 22. The sliding section 3 separates the sixth through hole 231 of the fixed sleeve 1 and the seventh through hole 232 of the sleeve 2, thereby sealing the third liquid inlet channel 23.

[0064] The outer cylinder liner 4 is coaxially fixed on the outside of the sleeve 2. A first seal 401 and a second seal 402 are provided between the outer cylinder liner 4 and the sleeve 2. The first seal 401 is located between the first liquid inlet channel 21 and the second liquid inlet channel 22, and the second seal 402 is located between the second liquid inlet channel 22 and the third liquid inlet channel 23. A liquid inlet 40 is provided on the side wall of the outer cylinder liner 4 between the first seal 401 and the second seal 402. A first annular space 61 and a second annular space 62 are provided between the outer cylinder liner 4 and the sleeve 2. The first annular space 61 is located below the second seal 402 and is connected to the third liquid inlet channel 23. The second annular space 62 is located above the first seal 401 and is connected to the first liquid inlet channel 21.

[0065] In this setting, when the sliding section 3 moves to... Figure 1 In the second state shown, the second inlet channel 22 is open and the third inlet channel 23 is closed. Fluid from the outside of the outer cylinder liner 4 can enter the interior of the fixed sleeve 1 through the inlet port 40 and the second inlet channel 22 in sequence. Then, the fluid flows upward along the fixed sleeve 1, passes through the first inlet channel 21 and the second annulus 62, and flows upward out of the fluid control valve 100.

[0066] When the sliding section 3 moves to Figure 2In the first state shown, the third inlet channel 23 is open and the second inlet channel 22 is closed. Fluid from the outside of the outer cylinder liner 4 can enter the interior of the fixed sleeve 1 from the lower port of the outer cylinder liner 4 through the first annular space 61 between the outer cylinder liner 4 and the sleeve 2, and then through the third inlet channel 23. Then, the fluid flows upward along the fixed sleeve 1, and flows upward through the first inlet channel 21 and the second annular space 62 before exiting the fluid control valve 100.

[0067] According to the present invention, the sliding section 3 is configured to switch between a first state and a second state under pressure.

[0068] Specifically, the upper and lower surfaces of the pressure transmission hole 31 are constructed as pressure difference surfaces. In this embodiment, the pressure-bearing area at the upper end of the pressure transmission hole 31 is greater than the pressure-bearing area at the lower end of the pressure transmission hole 31. When the pressure inside the pressure transmission hole 31 increases, the entire sliding section 3 will move upward under the action of the pressure difference.

[0069] A switching spring 33 is provided between the upper short section 32 and the sliding short section 3. The switching spring 33 is coaxially sleeved within the cavity 20 of the fixed sleeve 1 and the sleeve 2. The two axial ends of the switching spring 33 respectively abut against the upper short section 32 and the sliding short section 3, thereby providing an axially downward force to the sliding short section 3. With this configuration, when the pressure in the pressure transmission hole 31 decreases, the sliding short section 3 can move downward under the action of the switching spring 33.

[0070] like Figure 1 and Figure 3 As shown, a switch groove 34 is provided on the outer wall of the fixed sleeve 1. The switch groove 34 includes a first groove 341 and a second groove 342 with different axial lengths. A switch pin 35 is provided on the sliding short section 3 for matching the switch groove 34. The sliding short section 3 is configured to rotate relative to the fixed sleeve 1. The switch pin 35 switches between the first groove 341 and the second groove 342, thereby switching the sliding short section 3 between the first state and the second state.

[0071] In this embodiment, the length of the first slot 341 is less than the length of the second slot 342, meaning the lower end of the first slot 341 is higher than the lower end of the second slot 342. In the second state, when the switch pin 35 of the sliding section 3 is located in the first slot 341, and the pressure difference experienced by the pressure transmission hole 31 is less than the force of the switch spring 33, the switch pin 35 of the sliding section 3 moves to the lower end of the first slot 341. At this time, the fifth through hole 223 of the sliding section 3 connects the second liquid inlet channel 22. In the first state, when the switch pin 35 of the sliding section 3 is located in the second slot 342, and the pressure difference experienced by the pressure transmission hole 31 is less than the force of the switch spring 33, the switch pin 35 of the sliding section 3 moves to the lower end of the second slot 342. At this time, the fifth through hole 223 of the sliding section 3 connects the third liquid inlet channel 23.

[0072] Furthermore, such as Figure 3 As shown, a switching groove 36 is provided on the outer wall of the fixed sleeve 1. The switching groove 36 is located above the switch groove 34. When the sliding section 3 moves upward to contact the switching groove 36, the sliding section 3 can rotate a certain angle relative to the fixed sleeve 1 in the circumferential direction, thereby switching between the first groove 341 and the second groove 342. That is, when the pressure difference received by the pressure transmission hole 31 is greater than the force of the switch spring 33, the sliding section 3 moves upward to contact the switching groove 36. Under the action of the inclined surface of the switching groove 36, the sliding section 3 rotates a certain angle in the circumferential direction, and then reduces the pressure difference received by the pressure transmission hole 31, causing the sliding section 3 to move downward, completing the switching between the first groove 341 and the second groove 342, and realizing the switching between the first state and the second state.

[0073] According to the present invention, a one-way valve 5 is provided inside the fixed sleeve 1. The one-way valve 5 is configured to allow fluid to flow unidirectionally from the second inlet channel 22 to the first inlet channel 21. In this configuration, pressure can be applied from the upper port of the outer cylinder liner 4 inwards, and then the pressure is transmitted to the pressure transmission port 31 through the second annulus 62 and the second through hole 212 of the sleeve 2. The one-way valve 5 only allows fluid to flow unidirectionally from bottom to top. Therefore, the one-way valve 5 is in the closed state at this time, thereby continuously increasing the pressure in the pressure transmission port 31, which in turn continuously increases the pressure difference in the pressure transmission port 31, causing the sliding section 3 to move upwards.

[0074] In one specific embodiment, the one-way valve 5 includes a valve seat 51, a switching valve body 52, and a return spring 53.

[0075] The valve seat 51 is coaxially fixed inside the fixed sleeve 1, located between the first inlet channel 21 and the second inlet channel 22. The switch valve body 52 is axially movable inside the fixed sleeve 1 and positioned above the valve seat 51. When the switch valve body 52 seals against the valve seat 51 downwards, it seals the valve seat 51, thus closing the inner cavity of the fixed sleeve 1. In this configuration, when fluid flows downwards through the switch valve body 52, the fluid pushes the switch valve body 52 to close the valve seat 51, thereby preventing fluid flow. When fluid flows upwards through the switch valve body 52, the switch valve body 52 moves upwards under the action of the fluid, thus allowing fluid flow.

[0076] The return spring 53 is disposed between the upper short section 32 and the switch valve body 52. ​​The return spring 53 provides a downward return force to the switch valve body 52.

[0077] In a preferred embodiment, the one-way valve 5 further includes a support sleeve 54 disposed within the fixed sleeve 1, and a switch shaft 55 movably disposed within the support sleeve 54. The lower end of the switch shaft 55 is fixedly connected to the switch valve body 52. ​​The upper end of the switch shaft 55 is provided with a limiting section 56. The outer diameter of the limiting section 56 is larger than the inner diameter of the support sleeve 54. The limiting section 56 is located above the support sleeve 54 and can limit the axial movement of the switch valve body 52.

[0078] A central column 37 is also provided inside the fixed sleeve 1. The upper end of the central column 37 abuts axially with the upper short section 32, and the lower end of the central column 37 abuts axially with the return spring 53. The lower end of the return spring 53 abuts axially with the upper end of the limiting section 56.

[0079] In a preferred embodiment, a screen is provided at the inlet 40. Further, the screen portion can be a screen tube. In this embodiment, the outer cylinder liner 4 includes an upper connector 42, a cylinder 44, a screen tube (screen), and a lower connector 43, arranged coaxially from top to bottom. The screen tube can prevent scale or grit from entering the fluid control valve 100, thereby reducing wear on internal valve parts during sliding and extending the service life of the fluid control valve 100.

[0080] Example 2

[0081] According to the present invention, a multi-layer production tubing string for geothermal wells is also provided, such as... Figure 4 As shown, the geothermal well includes a production casing 105, which passes through the second reservoir 102 and the third reservoir 103 from top to bottom.

[0082] The upper and lower sides of the fluid control valve 100 are respectively installed in the production casing 105 through the first packer 104 and the second packer 106. The second reservoir 102 and the second inlet channel of the fluid control valve are located between the first packer 104 and the second packer 106. The third inlet channel of the fluid control valve is located below the second packer 106.

[0083] The wellhead installation process for multi-layer production tubing in geothermal wells is as follows: perforation completion is used for the second reservoir 102, and screen completion is used for the third reservoir 103.

[0084] The first packer 104 and the second packer 106 are coaxially arranged outside the outer cylinder liner 4 of the fluid control valve 100. The inlet 40 of the outer cylinder liner 4 is located between the first packer 104 and the second packer 106. After the fluid control valve 100 is inserted into the well, it sets the first packer 104 and the second packer 106, thus fixing the fluid control valve 100 in the well and separating the second reservoir 102 and the third reservoir 103 respectively. A submersible pump 109 is installed at the wellhead.

[0085] When the fluid control valve 100 is in the second state, the second inlet channel 22 of the fluid control valve 100 is open, and the third inlet channel 23 is closed. The geothermal water from the second reservoir 102 enters the fluid control valve 100 through the inlet 40 and the second inlet channel 22, and then flows upward out of the fluid control valve 100 through the first inlet channel 21 and the second annulus 62, entering the production casing 105 above the first packer 104. After the submersible pump 109 is turned on, the geothermal water in the second reservoir 102 is extracted.

[0086] When switching to geothermal water extraction from the third reservoir 103, pressure is applied from the wellhead into the well. The pressure is transmitted to the pressure transmission hole 31 through the upper port of the outer cylinder sleeve 4, the first annulus 61, and the first fluid inlet channel 21. This causes the sliding section 3 to move upward until it is in axial contact with the switching groove 36. Under the action of the inclined surface of the switching groove 36, the sliding section 3 rotates at a certain angle relative to the fixed sleeve 1, realizing the switching of the switching pin 35 of the sliding section 3 between the first groove position 341 and the second groove position 342. Then, the pressure into the well is reduced, causing the sliding section 3 to move downward, switching the fluid control valve 100 to the first state.

[0087] When the fluid control valve 100 is in the first state, the second inlet channel 22 of the fluid control valve 100 is closed, and the third inlet channel 23 is open. The geothermal water from the third reservoir 103 enters the fluid control valve 100 through the lower port of the outer cylinder liner 4, the first annulus 61, and the third inlet channel 23. Then, it flows upward out of the fluid control valve 100 through the first inlet channel 21 and the second annulus 62, and enters the production casing 105 above the first packer 104. After the submersible electric pump 109 is turned on, the geothermal water in the third reservoir 103 is extracted.

[0088] Different reservoirs can be exploited based on their geothermal water reserves and temperature, combined with on-site requirements. In this embodiment, compared to embodiment three, since there is no central pipe 107 in the upper wellbore, a high-power submersible pump 109 can be used to achieve large-volume extraction.

[0089] Example 3

[0090] In another embodiment of the multi-layer production tubing for geothermal wells provided according to the present invention, such as Figure 5 As shown, based on Embodiment 2, a first reservoir 101 is provided above the first packer 104, a central tube 107 is provided at the upper end of the fluid control valve 100, and a submersible electric pump 109 is provided in the central tube 107 and in the annulus between the central tube 107 and the production casing 105.

[0091] The first reservoir 101 and the second reservoir 102 were completed using perforation, while the third reservoir 103 was completed using screen pipe.

[0092] The first packer 104 and the second packer 106 are coaxially arranged outside the outer cylinder liner 4 of the fluid control valve 100. The inlet 40 of the outer cylinder liner 4 is located between the first packer 104 and the second packer 106. After the fluid control valve 100 is inserted into the well, it sets the first packer 104 and the second packer 106, thereby fixing the fluid control valve 100 in the well and separating the first reservoir 101, the second reservoir 102, and the third reservoir 103 respectively.

[0093] The rest of the structure is the same as in Example 2.

[0094] In this setup, both submersible pumps 109 are activated simultaneously. One submersible pump 109 extracts geothermal water from the first reservoir 101, while the other submersible pump 109, switched by the fluid control valve 100, extracts geothermal water from the second reservoir 102 and the third reservoir 103 independently. This allows for simultaneous extraction of the first reservoir 101 and the second reservoir 102. Alternatively, it allows for simultaneous extraction of the first reservoir 101 and the third reservoir 103.

[0095] Therefore, different reservoirs can be exploited based on the reservoir's geothermal water reserves and temperature, combined with on-site requirements.

[0096] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0097] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., 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 according to the specific circumstances.

[0098] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0099] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fluid control valve, characterized in that, include: Fixing sleeve (1); A sleeve (2) is coaxially arranged on the outside of the fixed sleeve (1). A first liquid inlet channel, a second liquid inlet channel and a third liquid inlet channel are arranged sequentially along the axial direction between the fixed sleeve (1) and the sleeve (2). A cavity (20) is arranged between the fixed sleeve (1) and the sleeve (2). A sliding short section (3) is movably disposed in the cavity (20). In a first state, the sliding short section (3) blocks the second liquid inlet channel, and in a second state, the sliding short section (3) blocks the third liquid inlet channel. as well as An outer cylinder sleeve (4) is coaxially disposed on the outside of the sleeve (2). A first seal (401) and a second seal (402) are disposed between the outer cylinder sleeve (4) and the sleeve (2). The first seal (401) is located between the first liquid inlet channel and the second liquid inlet channel, and the second seal (402) is located between the second liquid inlet channel and the third liquid inlet channel. An inlet (40) is disposed on the side wall of the outer cylinder sleeve (4) between the first seal (401) and the second seal (402).

2. The fluid control valve according to claim 1, characterized in that, The sliding section (3) is configured to switch between the first state and the second state under pressure.

3. The fluid control valve according to claim 2, characterized in that, A pressure-transmitting hole (31) is provided on the side wall of the sliding section (3). The pressure-transmitting hole (31) is connected to the first liquid inlet channel. The upper and lower surfaces of the pressure-transmitting hole (31) are constructed as differential pressure surfaces.

4. The fluid control valve according to claim 3, characterized in that, An upper short section (32) is provided between the sleeve (2) and the fixed sleeve (1). A switch spring (33) is provided between the upper short section (32) and the sliding short section (3). A switch groove (34) is provided on the outer wall of the fixed sleeve (1). The switch groove (34) includes a first groove and a second groove with different axial lengths. A switch pin (35) is provided on the sliding short section (3) for adapting to the switch groove (34). The sliding short section (3) is configured to rotate relative to the fixed sleeve (1). The switch pin (35) switches between the first groove and the second groove, thereby switching the sliding short section (3) between the first state and the second state.

5. The fluid control valve according to claim 4, characterized in that, A switching groove (36) is provided on the outer wall of the fixed sleeve (1). The switching groove (36) is located above the switch groove (34). When the sliding section (3) moves upward to contact the switching groove (36), the sliding section (3) can rotate to switch between the first groove and the second groove.

6. The fluid control valve according to claim 5, characterized in that, A one-way valve (5) is provided inside the fixed sleeve (1). The one-way valve (5) is configured to allow fluid to flow unidirectionally from the second inlet channel to the first inlet channel.

7. The fluid control valve according to claim 6, characterized in that, The one-way valve (5) includes: A valve seat (51) is disposed on the inner side of the fixed sleeve (1), and the valve seat (51) is located between the first liquid inlet channel and the second liquid inlet channel; An axially movable switch valve body (52) is provided in the fixed sleeve (1) for fitting the valve seat (51), the switch valve body (52) being located above the valve seat (51); A return spring (53) is provided between the upper short section (32) and the switch valve body (52); The support sleeve (54) is disposed within the fixed sleeve (1); and A switch shaft (55) is movably disposed within the support sleeve (54). The lower end of the switch shaft (55) is connected to the switch valve body (52). The upper end of the switch shaft (55) is provided with a limiting section (56), which is located above the support sleeve (54).

8. The fluid control valve according to any one of claims 1 to 7, characterized in that, A screen is provided at the liquid inlet (40).

9. A multi-layered production tubing string for geothermal wells, characterized in that, The geothermal well includes a production casing (105) that passes through the second reservoir (102) and the third reservoir (103) from top to bottom. According to any one of claims 1 to 8, the upper and lower sides of the fluid control valve are respectively provided in the production casing (105) through a first packer (104) and a second packer (106), and the second reservoir (102) and the inlet (40) of the fluid control valve are located between the first packer (104) and the second packer (106).

10. The multi-layer production tubing string for geothermal wells according to claim 9, characterized in that, A first reservoir (101) is provided above the first packer (104), and a central tube (107) is provided at the upper end of the fluid control valve according to any one of claims 1 to 8.

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