A downhole choke, a downhole choke system, an oilfield gas production system and applications thereof

Abstract

The application discloses a downhole throttler, a downhole throttling system, an oilfield gas production system and application thereof. The downhole throttler comprises a central pipe, an anchoring assembly and a sealing assembly which are arranged outside the central pipe. The anchoring assembly comprises a slip seat, slips, a slip cover, a cone and a slip cover pressing cap. The slip seat and the cone are arranged outside the central pipe. The slip cover is arranged outside the slip seat and the cone, and the slip cover pressing cap is arranged outside the cone and is limited by the cone. The proximal end of the slip cover is detachably connected with the slip cover pressing cap. The slip is arranged in the slip cover, and the distal end of the slip is limited by the slip seat, and the proximal end of the slip is in abutment with the conical surface of the cone. The sealing assembly comprises a rubber sleeve upper shoulder, a rubber sleeve and a rubber sleeve lower shoulder. The rubber sleeve is arranged between the rubber sleeve upper shoulder and the rubber sleeve lower shoulder, and the rubber sleeve upper shoulder is detachably connected with the cone. The application realizes linkage setting and releasing of the slip and the rubber sleeve, and effectively improves setting and fishing releasing efficiency.

Description

Technical Field

[0001] This invention relates to the field of oilfield gas development technology, and in particular to a downhole throttling device, a downhole throttling system, an oilfield gas production system, and their applications. Background Technology

[0002] Currently, downhole throttling technology is widely used to transform traditional surface throttling and pressure reduction into downhole throttling and pressure reduction. This fully utilizes geothermal heating to ensure that the temperature of the gas flow after downhole throttling is higher than the critical temperature at which a gas-water mixture forms under the pressure conditions after throttling. This effectively inhibits hydrate formation and reduces surface pipeline pressure during gas well production. Downhole throttling technology relies on downhole throttling nozzles to achieve pressure reduction in the gas wellbore. While reducing pressure, it prevents the formation of wellbore hydrates, thus avoiding blockages in surface equipment. Summary of the Invention

[0003] The implementation of downhole throttling technology relies on throttling tools installed in the wellbore. The inventors have discovered the following problems in the field application of downhole throttling devices: (1) Due to the inability of the slips and rubber sleeves to be linked in their structural design, the slips and rubber sleeves cannot be retrieved synchronously during the retrieval process, making retrieval of the throttling device difficult or even impossible; (2) Conventional throttling devices have poor sand-proof performance, resulting in sand burial at the top of the throttling device, causing retrieval difficulties. In view of the above problems, this invention is proposed to provide a downhole throttling device, a downhole throttling system, an oilfield gas production system, and their applications that overcome or at least partially solve the above problems.

[0004] In a first aspect, embodiments of the present invention provide a downhole choke, which may include: a central tube and an anchoring assembly and a sealing assembly sleeved outside the central tube;

[0005] The anchoring assembly includes: a slip seat, slips, a slip cover, a cone, and a slip cover cap; the slip seat and the cone are fitted over the center tube; the slip cover is fitted over the slip seat and the cone, and the slip cover cap is fitted over the cone and limited by the cone; the proximal end of the slip cover is detachably connected to the slip cover cap; the slips are installed inside the slip cover, and the distal end of the slips is limited by the slip seat, and the proximal end of the slips abuts against the conical surface of the cone;

[0006] The sealing assembly includes: an upper shoulder of the rubber sleeve, a rubber sleeve, and a lower shoulder of the rubber sleeve; the rubber sleeve is located between the upper shoulder of the rubber sleeve and the lower shoulder of the rubber sleeve, and the upper shoulder of the rubber sleeve is detachably connected to the cone;

[0007] The slips expand to anchor the inner wall of the tubing in the well to be set, and the slip cover drives the cone to compress the upper shoulder of the rubber sleeve, and under the combined action of the lower shoulder of the rubber sleeve, the rubber sleeve is squeezed to seal the tubing to achieve the setting of the well.

[0008] The slips are released from anchor and returned to their original position. The slip cover moves the rubber sleeve and the upper shoulder slides through the cone. The rubber sleeve returns to its original position to unseal the set well.

[0009] Optionally, the inner side of the slip cover has a groove, and the slip is disposed in the groove so that at least a portion of the slip is covered by the slip cover.

[0010] Optionally, the anchoring assembly may further include: a spring piece located between the slip cover and the slip; the slip expands to compress the spring piece so that the spring piece stores force; the slip releases the anchor, and the spring piece acts on the slip to return the slip to its original position.

[0011] Optionally, the downhole throttle may further include: a deployment component, a retrieval component, a locking component, and a throttling component;

[0012] The salvage assembly is sleeved on the outside of the central tube and detachably connected to the distal end of the central tube; the deployment assembly is riveted to the distal end of the salvage assembly; the locking seat is sleeved on the outside of the proximal end of the salvage assembly and detachably connected to the salvage assembly.

[0013] The locking sleeve of the locking assembly is located between the central tube, the anchoring assembly, and the sealing assembly, and has a preset gap in the axial direction with the retrieval assembly for locking the anchoring assembly and the sealing assembly.

[0014] The lower shoulder guard of the rubber tube is connected to the locking ring cover of the locking assembly;

[0015] The throttling assembly is located on the inner side of the proximal end of the central tube.

[0016] Optionally, the locking assembly may include: a locking sleeve, a locking ring, a locking ring cap, and a locking ring cover;

[0017] The locking sleeve is fitted outside the central tube, and its distal end is limited by the salvage component.

[0018] The locking ring is sleeved on the outside of the locking sleeve and is detachably connected to the proximal end of the locking sleeve;

[0019] The locking ring cap is fitted over the locking sleeve and the locking ring, and engages with the locking sleeve.

[0020] The locking ring cover is fitted over the locking ring and the locking ring cap, and limits the position of the locking ring cap.

[0021] Optionally, the distal end of the locking sleeve is provided with a spring claw, and the inner surface of the middle sleeve of the retrieval assembly is provided with a groove, and the locking sleeve is limited to the groove by the spring claw;

[0022] The locking sleeve has a first barb at its proximal end, and the locking ring cap has a second barb that matches the first barb. The locking ring cap engages with the locking sleeve.

[0023] Optionally, the salvage assembly may include: a salvage sleeve, a salvage sleeve liner, a salvage shear pin seat, salvage shear pins, an intermediate sleeve, and a pressure cap;

[0024] The retrieval sleeve liner is detachably connected to the central tube. The retrieval sleeve is fitted over the outside of the retrieval sleeve liner, and the retrieval sleeve can be limited by the proximal end of the retrieval sleeve liner.

[0025] The salvage shear pin seat is sleeved on the salvage sleeve and is detachably connected to the proximal end of the salvage sleeve;

[0026] The intermediate sleeve is fitted outside the retrieval shear pin seat and is limited by the retrieval shear pin. The intermediate sleeve is detachably connected to the slip seat.

[0027] The pressure cap is fitted outside the retrieval sleeve and connected to the intermediate sleeve, and is used to limit the position of the retrieval shear nail seat.

[0028] Optionally, the dispensing component may include: a hand-dropping device and a hand-dropping scissors device;

[0029] The release head is nested inside the retrieval sleeve liner and is limited by the release shear nail.

[0030] Optionally, the downhole choke may further include: a connecting assembly and a screen, the connecting assembly being used to connect the screen to the proximal end of the center tube;

[0031] The distal end of the screen tube abuts against the throttling assembly;

[0032] The connecting assembly includes: a transfer sleeve, a lower connecting sleeve, a gasket, and a connecting cap;

[0033] The intermediate sleeve and the lower connecting sleeve are sleeved outside the central tube and are detachably connected to the proximal end of the central tube. The distal end of the intermediate sleeve abuts against the locking ring cover of the locking assembly.

[0034] The gasket is located between the intermediate sleeve and the lower connecting sleeve;

[0035] The connecting cap is fitted over the locking ring cover and the transfer sleeve. The connecting cap is detachably connected to the locking ring cover and snaps into the transfer sleeve.

[0036] Optionally, the sieve tube is provided with at least two stages of foamed nickel-copper alloy filler, and the foamed nickel-copper alloy filler is provided with a porous structure.

[0037] Secondly, embodiments of the present invention provide a downhole throttling system, which may include: a dispensing device and the downhole throttling device described in the first aspect;

[0038] The delivery device is used to set the downhole choke at a preset position using the delivery component.

[0039] Optionally, the system may further include: a retrieval device for unsealing and retrieving the downhole throttle via the retrieval assembly.

[0040] Thirdly, embodiments of the present invention provide an oilfield gas production system, which may include: an oil pipe and a downhole choke as described in the first aspect;

[0041] The downhole throttle is used to be set at a preset position in the tubing to seal the tubing at the preset position.

[0042] Fourthly, embodiments of the present invention provide an application of the downhole throttle described in the first aspect in an oilfield gas production system.

[0043] The beneficial effects of the above-mentioned technical solutions provided in the embodiments of the present invention include at least the following:

[0044] This invention provides a downhole choke, a downhole choke system, an oilfield gas production system, and their applications. The downhole choke may include: a central tube and an anchoring assembly and a sealing assembly sleeved outside the central tube.

[0045] The anchoring assembly includes: a slip seat, slips, a slip cover, a cone, and a slip cover cap; the slip seat and the cone are fitted over the center tube; the slip cover is fitted over the slip seat and the cone, and the slip cover cap is fitted over the cone and limited by the cone; the proximal end of the slip cover is detachably connected to the slip cover cap; the slips are installed inside the slip cover, and the distal end of the slips is limited by the slip seat, and the proximal end of the slips abuts against the conical surface of the cone;

[0046] The sealing assembly includes: an upper shoulder of the rubber sleeve, a rubber sleeve, and a lower shoulder of the rubber sleeve; the rubber sleeve is located between the upper shoulder of the rubber sleeve and the lower shoulder of the rubber sleeve, and the upper shoulder of the rubber sleeve is detachably connected to the cone;

[0047] The slips expand to anchor the inner wall of the tubing in the well to be set, and the slip cover drives the cone to compress the upper shoulder of the rubber sleeve, and under the combined action of the lower shoulder of the rubber sleeve, the rubber sleeve is squeezed to seal the tubing to achieve the setting of the well.

[0048] The slips are released from anchor and returned to their original position. The slip cover moves the rubber sleeve and the upper shoulder slides through the cone. The rubber sleeve returns to its original position to unseal the set well.

[0049] The inventors addressed the shortcomings of existing technologies where the anchoring and sealing components are separate and not connected. This resulted in a lack of real-time linkage between anchoring and sealing during setting and unsealing, meaning the slips and rubber sleeve could not be simultaneously anchored during setting, and could not be synchronously retrieved during unsealing. This led to difficulties in anchoring and sealing during setting, or even made retrieval difficult or impossible during unsealing. To overcome these drawbacks, the inventors innovatively proposed connecting the anchoring and sealing components, enabling synchronized setting and unsealing of the slips and rubber sleeve, effectively improving the efficiency of both setting and retrieval / unsealing.

[0050] Furthermore, the slips are installed inside the slip cover, which has an inner groove design to effectively prevent sand from getting stuck in the slips and to assist in unsealing the slips. In this embodiment of the invention, the slip cover has a groove at the position where the slips are installed, which, compared with conventional downhole chokes, avoids sand getting stuck due to sand filling the gaps.

[0051] Other features and advantages of the invention will be set forth in the following description, 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 and the accompanying drawings.

[0052] 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

[0053] 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:

[0054] Figure 1 This is a schematic diagram of the downhole throttle provided in an embodiment of the present invention;

[0055] Figure 2 This is a schematic diagram of the downhole throttle portion of the structure provided in an embodiment of the present invention;

[0056] Figure 3 This is a schematic diagram of the structure of the sieve tube provided in an embodiment of the present invention;

[0057] Among them, 1 is the central tube; 2 is the anchoring assembly; 3 is the sealing assembly; 4 is the delivery assembly; 5 is the retrieval assembly; 6 is the locking assembly; 7 is the throttling assembly; 8 is the connecting assembly; and 9 is the screen tube.

[0058] 21 is the slip seat; 22 is the slip; 23 is the slip cover; 24 is the cone; 25 is the slip cover cap; 26 is the spring clip; 231 is the groove;

[0059] 31 is the upper shoulder protector of the rubber sleeve; 32 is the rubber sleeve; 33 is the lower shoulder protector of the rubber sleeve;

[0060] 41 means losing what you have; 42 means losing what you have cut and nail.

[0061] 51 is the salvage sleeve; 52 is the inner lining of the salvage sleeve; 53 is the salvage shear pin holder; 54 is the salvage shear pin; 55 is the intermediate sleeve; 56 is the pressure cap;

[0062] 61 is the locking sleeve; 62 is the locking ring cover; 63 is the locking ring; 64 is the locking ring cap;

[0063] 81 is the intermediate sleeve; 82 is the lower connecting sleeve; 83 is the gasket; 84 is the connecting cap;

[0064] 91 is a foamed nickel-copper alloy filler. Detailed Implementation

[0065] 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.

[0066] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "far," "near," "front," and "rear," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this invention and 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, and therefore should not be construed as a limitation of this 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.

[0067] 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.

[0068] This invention provides a downhole throttle device, referring to... Figure 1 and Figure 2 As shown, the downhole choke may include: a central tube 1 and an anchoring assembly 2 and a sealing assembly 3 sleeved outside the central tube 1;

[0069] The anchoring assembly 2 may include: a slip seat 21, a slip 22, a slip cover 23, a cone 24, and a slip cover cap 25; the slip seat 21 and the cone 24 are fitted over the center tube 1; the slip cover 23 is fitted over the slip seat 21 and the cone 24, and the slip cover cap 25 is fitted over the cone 24 and is limited by the cone; the proximal end of the slip cover 23 is detachably connected to the slip cover cap 25; the slip 22 is installed inside the slip cover 23, and the distal end of the slip 22 is limited by the slip seat 21, and the proximal end of the slip 22 abuts against the conical surface of the cone 24;

[0070] The sealing assembly 3 may include: an upper shoulder 31, a rubber tube 32, and a lower shoulder 33; the rubber tube 32 is located between the upper shoulder 31 and the lower shoulder 33, and the upper shoulder 31 is detachably connected to the cone 24.

[0071] The slip 22 expands to anchor the inner wall of the tubing in the well to be set, and the slip cover 23 drives the cone 24 to compress the upper shoulder 31 of the rubber sleeve, and under the combined action of the lower shoulder 33 of the rubber sleeve, the rubber sleeve 32 is squeezed to seal the tubing so as to achieve the setting of the well to be set.

[0072] The slip 22 releases the anchor and returns to its original position. The slip cover 23 drives the upper shoulder 31 of the rubber sleeve to slide through the cone 24, and the rubber sleeve 32 returns to its original position to achieve the unsealing of the set well.

[0073] In the normal use of the downhole choke in this embodiment of the invention, the anchoring assembly is located above the sealing assembly. In this embodiment of the invention, the upper end of all components is taken as the far end, and the lower end of all components is taken as the near end.

[0074] The inventors addressed the shortcomings of existing technologies where the anchoring and sealing components are separate and not connected. This resulted in a lack of real-time linkage between anchoring and sealing during setting and unsealing, meaning the slips and rubber sleeve could not be simultaneously anchored during setting, and could not be synchronously retrieved during unsealing. This led to difficulties in anchoring and sealing during setting, or even made retrieval difficult or impossible during unsealing. To overcome these drawbacks, the inventors innovatively proposed connecting the anchoring and sealing components, enabling synchronized setting and unsealing of the slips and rubber sleeve, effectively improving the efficiency of both setting and retrieval / unsealing.

[0075] During the setting process, one end of the slip is limited by the slip seat, and the cone moves upward relative to the central tube. The conical surface of the cone expands the slip to anchor it to the inner wall of the tubing in the set well. At the same time, the cone axially limits the upper shoulder of the rubber sleeve, and the upper and lower shoulders of the rubber sleeve compress the rubber sleeve to achieve a seal between the rubber sleeve and the tubing. During the unsealing process, the slip seat is released from its limiting position, the slip contacts the anchor and returns to its original position, the slip cover drives the cone upward, and the cone drives the upper shoulder of the rubber sleeve upward. The slip and the rubber sleeve work together to complete the unsealing of the downhole choke.

[0076] Furthermore, in specific implementations, the upper shoulder protector, the rubber tube, and the lower shoulder protector of the rubber tube in the embodiments of the present invention can be integrally formed, or designed separately and then assembled together for use. The integral rubber tube structure, with the rubber tube and the rubber tube shoulder protector integrated, has a skeleton that allows for forced unsealing of the rubber tube, effectively avoiding the occurrence of difficulty in unsealing due to rubber aging.

[0077] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, a groove 231 is provided on the inner side of the cover 23, and the cover 22 is disposed in the groove 231 so that at least part of the cover 23 encloses the cover 23.

[0078] In existing technologies, the slips of anchoring components are completely exposed, often leading to sand jamming during use. This causes the slips to fail to fully expand or fully retract. The inventors have addressed this by adding a slip cover structure. Through a unique slip cover design, the slips are installed inside the cover, which features an internal groove design to effectively prevent sand jamming and assist in slip release. In this embodiment, the slip cover has a groove at the slip installation location, which, compared to conventional downhole chokes, avoids sand jamming caused by gravel filling the gaps.

[0079] It should be noted that the detachable connection described above in the embodiments of the present invention can be a threaded connection between various components, or other detachable connection methods, as long as they are applicable to the normal operation of the downhole throttle. The embodiments of the present invention do not specifically limit the detachable connection methods described above.

[0080] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the anchoring assembly 2 may further include: a spring piece 26 located between the slip cover 23 and the slip 22; the slip 22 expands to compress the spring piece 26, causing the spring piece 26 to store force; the slip 22 releases the anchoring, and the spring piece 26 acts on the slip 22 to return the slip 22 to its original position. The compression and rebound of the spring piece in the above embodiment of the present invention can effectively assist in the anchoring and release of the slip.

[0081] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the downhole throttle may also include: a deployment component 4, a retrieval component 5, a locking component 6, and a throttling component 7;

[0082] The salvage component 5 is sleeved on the outside of the central tube 1 and detachably connected to the far end of the central tube 1. The deployment component 4 is riveted to the far end of the salvage component 5. The clamp seat 21 is sleeved on the outside of the near end of the salvage component 5 and detachably connected to the salvage component 5.

[0083] The locking sleeve 61 of the locking assembly 6 is located between the central tube 1, the anchoring assembly 2, and the sealing assembly 3, and has a preset gap in the axial direction with the retrieval assembly 5, for locking the anchoring assembly 2 and the sealing assembly 3.

[0084] The lower shoulder guard 33 of the rubber tube is connected to the locking ring cover 62 of the locking assembly 6;

[0085] The throttling assembly 7 is located on the inner side of the proximal end of the central tube 1.

[0086] It should be noted that, in the embodiments of the present invention, the locking sleeve 61 of the locking component 6 is fitted outside the central tube 1, and a portion of the slip seat 21, slip 22, cone 24, etc. of the anchoring component 2, as well as the upper shoulder 31, sleeve 32 and lower shoulder 33 of the sealing component 3 are fitted outside the locking sleeve 61, so that the other components of the locking component 6 lock the anchoring component 2 and the sealing component 3.

[0087] In an optional embodiment, the above-mentioned throttling component may include a plurality of nozzles, or of course, nozzle seats and other components, and the embodiments of the present invention do not specifically limit this.

[0088] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the locking component 6 may include: a locking sleeve 61, a locking ring 63, a locking ring cap 64, and a locking ring cover 62;

[0089] The locking sleeve 61 is fitted outside the central tube 1, and its far end is limited by the retrieval component 5; specifically, the middle sleeve of the retrieval component 5 is limited.

[0090] The locking ring 63 is sleeved on the outside of the locking sleeve 61 and is detachably connected to the proximal end of the locking sleeve 61;

[0091] The locking ring cap 64 is sleeved on the outside of the locking sleeve 61 and the locking ring 63, and is engaged with the locking sleeve 61.

[0092] The locking ring cover 62 is fitted over the locking ring 63 and the locking ring cap 64 and limits the locking ring cap 64.

[0093] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the distal end of the locking sleeve 61 is provided with a spring claw (not shown in the figure), and the inner surface of the middle sleeve of the retrieval assembly 5 is provided with a groove, and the locking sleeve is limited to the groove by the spring claw.

[0094] The locking sleeve has a first barb at its proximal end, and the locking ring cap has a second barb that matches the first barb. The locking ring cap engages with the locking sleeve.

[0095] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the salvage assembly 5 may include: a salvage sleeve 51, a salvage sleeve liner 52, a salvage shear pin seat 53, a salvage shear pin 54, an intermediate sleeve 55, and a pressure cap 56;

[0096] The retrieval sleeve liner 52 is detachably connected to the central tube 1. The retrieval sleeve 51 is fitted over the retrieval sleeve liner 52, and the retrieval sleeve 51 can be limited by the proximal end of the retrieval sleeve liner 52.

[0097] The salvage shear nail seat 53 is sleeved on the salvage sleeve 51 and is detachably connected to the proximal end of the salvage sleeve 51.

[0098] The intermediate sleeve 55 is fitted outside the retrieval shear nail seat 53 and is limited by the retrieval shear nail 54. The intermediate sleeve 55 is detachably connected to the slip seat 21.

[0099] The pressure cap 56 is fitted outside the retrieval sleeve 51 and connected to the intermediate sleeve 55 to limit the retrieval shear nail seat 53.

[0100] In embodiments of the present invention, such as Figure 1 and Figure 2 As shown, a portion of the retrieval sleeve 51 protrudes and has a predetermined stroke near the proximal end of the retrieval sleeve liner 52, thereby limiting the retrieval sleeve 51 within the retrieval sleeve liner 52. That is, during the retrieval process, the retrieval sleeve 51 can only increase this stroke distance to cut the retrieval shear pin 54. In specific implementation, the pressure cap 56 and the retrieval shear pin seat 53 have a predetermined stroke; after the retrieval shear pin seat 53 moves upward to cut the retrieval shear pin 54, it abuts against the pressure cap 56.

[0101] In an optional embodiment, refer to Figure 1 and Figure 2As shown, the delivery component 4 may include: a dropper head 41 and a dropper clipper 42; the dropper head 41 is nested in the retrieval sleeve liner 52 and is limited by the dropper clipper 42.

[0102] In this embodiment of the invention, the dropper is nested at the far end of the retrieval sleeve liner, and a through hole is provided at the far end of both the dropper and the retrieval sleeve liner. The dropper scissors are inserted into the through hole to connect the dropper and the retrieval sleeve liner.

[0103] In an optional embodiment, refer to Figure 1 and Figure 2 As shown, the downhole throttle may also include: a connecting assembly 8 and a screen pipe 9, wherein the connecting assembly 8 is used to connect the screen pipe 9 to the proximal end of the center pipe 1;

[0104] The distal end of the screen tube 9 abuts against the throttling assembly 7;

[0105] The connecting component 8 may include: a transfer sleeve 81, a lower connecting sleeve 82, a gasket 83, and a connecting cap 84;

[0106] The intermediate sleeve 81 and the lower connecting sleeve 82 are sleeved outside the central tube 1 and are detachably connected to the near end of the central tube 1. The far end of the intermediate sleeve 81 abuts against the locking ring cover 62 of the locking assembly 6.

[0107] Gasket 83 is located between intermediate sleeve 81 and lower connecting sleeve 82;

[0108] The connecting cap 84 is sleeved on the outside of the locking ring cover 62 and the transfer sleeve 81. The connecting cap 84 is detachably connected to the locking ring cover 62 and snapped into the transfer sleeve 81.

[0109] In an optional embodiment, refer to Figure 1 and Figure 3 As shown, the sieve tube 9 is provided with at least two stages of foamed nickel-copper alloy filler 91, and the foamed nickel-copper alloy filler 91 is configured with a porous structure. In this embodiment of the invention, the two stages of filler are 0.2 mm foamed nickel-copper alloy filler and 1 mm foamed nickel-copper alloy filler, respectively.

[0110] In this embodiment of the invention, the sand-proof pipe of the downhole throttle adopts a short section structure of screen pipe. The screen pipe is filled with two-stage precision foam nickel-copper alloy, which has high sand-proof accuracy, strong erosion resistance, and long service life. The filling material in the sand-proof pipe is a spatial sand-proof material. Compared with planar slotted sand-proof material, the pore throat structure design of the foam nickel-copper alloy filling material has low flow resistance, which can effectively increase the flow area and will not affect the throttling effect of the throttle nozzle.

[0111] The specific working principle of the downhole throttle in this embodiment of the invention is as follows:

[0112] Downhole choke setting process: The downhole choke is connected in sequence at the wellhead to a wire rope and a vibrator, etc. The deployment equipment is connected to the downhole choke via a release head 41. The downhole choke descends naturally, with the slips 22 relaxed and the rubber sleeve 32 in a naturally contracted state. Upon reaching the designed position, the wire rope is suddenly pulled upwards, causing the connected tubing string consisting of the release head 41, release shear pin 42, retrieval sleeve liner 52, center tube 1, lower connecting sleeve 82, gasket 83, intermediate sleeve 81, connecting cap 84, locking ring cover 62, locking ring 63, and locking ring cap 64 to move upwards. At this time, the pressure cap 56, intermediate sleeve 55, retrieval shear pin seat 53, retrieval shear pin 54, slip seat 21, slip cover 23, slips 22, and spring 26... The second tubing string, consisting of cone 24, slip cover cap 25, locking sleeve 61, upper shoulder of rubber sleeve 31, rubber sleeve 32, and lower shoulder of rubber sleeve 33, is not fixedly connected to the first tubing string. Under the action of inertia, it moves downward. Under the action of impact, the slip expands and anchors the inner wall of the oil pipe. At the same time, slip cover 23 drives cone 24 connected to it to move downward, so that rubber sleeve squeezes and seals the inner wall of the oil pipe. It continues to increase the upward lifting force, cuts the release shear pin 42, and completes the setting and release.

[0113] Downhole throttle unsealing process: The retrieval equipment is connected through the retrieval sleeve 51, which drives the retrieval shear nail seat 53 connected to it to move upward, increasing the lifting force and cutting the retrieval shear nail 54. At this time, the locking sleeve 61 is released from its limit, and its elastic claw retracts, which drives the slip 22 to release its anchoring and return to its original position. The slip cover 23 drives the cone 24 to move upward, and the rubber sleeve 32 seal is released, completing the throttle unsealing.

[0114] Based on the same inventive concept, this embodiment of the invention provides a downhole throttling system, which may include: a delivery device and the downhole throttling device described above;

[0115] The delivery device is used to set the downhole choke in a preset position using the delivery component.

[0116] In the above-mentioned downhole choke in the embodiment of the present invention, during the setting process, a wire rope and a shock device are sequentially connected to the wellhead. The choke is connected to the downhole choke through a release mechanism. The choke descends in a natural state. During the descent, the slips loosen and the rubber sleeve is in a natural contraction state.

[0117] In an optional embodiment, the downhole throttling system may further include: a retrieval device for unsealing and retrieving the downhole throttling device via a retrieval assembly.

[0118] The deployment and retrieval devices described in the embodiments of the present invention can use existing deployment and retrieval devices, and the embodiments of the present invention do not impose specific limitations on them.

[0119] Based on the same inventive concept, this embodiment of the invention provides an oilfield gas production system, which may include: an oil pipe and the aforementioned downhole choke;

[0120] Downhole chokes are used to be set at a predetermined position in the tubing to seal off the tubing at that predetermined position.

[0121] Based on the same inventive concept, this embodiment of the invention also provides an application of the above-mentioned downhole throttle in an oilfield gas production system.

[0122] The relevant descriptions and beneficial effects of the downhole throttling system, oilfield gas production system and downhole throttling device in the oilfield gas production system described in the embodiments of the present invention can be referred to the section on downhole throttling devices, and will not be repeated here.

[0123] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. This disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims. Thus, if these modifications and variations of the invention fall within the scope of the claims of the invention and their equivalents, the invention is also intended to include these modifications and variations.

Claims

1. A downhole throttle, characterized in that, include: A central tube and an anchoring assembly and a sealing assembly fitted over the central tube; The anchoring assembly includes: a slip seat, slips, a slip cover, a cone, a slip cover pressure cap, and a spring clip; the slip seat and the cone are fitted over the outside of the central tube; the slip cover is fitted over the slip seat and the cone, and the slip cover pressure cap is fitted over the cone and limited by the cone; the proximal end of the slip cover is detachably connected to the slip cover pressure cap; a groove is provided on the inner side of the slip cover, and the slip is disposed in the groove so that at least a portion of the slip is covered by the slip cover, and the distal end of the slip is limited by the slip seat, and the proximal end of the slip abuts against the conical surface of the cone; The sealing assembly includes: an upper shoulder of the rubber sleeve, a rubber sleeve, and a lower shoulder of the rubber sleeve; the rubber sleeve is located between the upper shoulder of the rubber sleeve and the lower shoulder of the rubber sleeve, and the upper shoulder of the rubber sleeve is detachably connected to the cone; The spring is located between the slip cover and the slip; the slip expands to compress the spring, causing the spring to store force; the slip releases its anchoring, and the spring acts on the slip to return the slip to its original position. The slips expand to anchor the inner wall of the tubing in the well to be set, and the slip cover drives the cone to compress the upper shoulder of the rubber sleeve, and under the combined action of the lower shoulder of the rubber sleeve, the rubber sleeve is squeezed to seal the tubing to achieve the setting of the well. The slips are released from anchor and returned to their original position. The slip cover moves the rubber sleeve and the upper shoulder slides through the cone. The rubber sleeve returns to its original position to unseal the set well.

2. The downhole throttle according to claim 1, characterized in that, The downhole throttle also includes: a deployment component, a retrieval component, a locking component, and a throttling component; The salvage assembly is sleeved on the outside of the central tube and detachably connected to the distal end of the central tube; the deployment assembly is riveted to the distal end of the salvage assembly; the locking seat is sleeved on the outside of the proximal end of the salvage assembly and detachably connected to the salvage assembly. The locking sleeve of the locking assembly is located between the central tube, the anchoring assembly, and the sealing assembly, and has a preset gap in the axial direction with the retrieval assembly for locking the anchoring assembly and the sealing assembly. The lower shoulder guard of the rubber tube is connected to the locking ring cover of the locking assembly; The throttling assembly is located on the inner side of the proximal end of the central tube.

3. The downhole throttle according to claim 2, characterized in that, The locking assembly includes: a locking sleeve, a locking ring, a locking ring cap, and a locking ring cover; The locking sleeve is fitted outside the central tube, and its distal end is limited by the salvage component. The locking ring is sleeved on the outside of the locking sleeve and is detachably connected to the proximal end of the locking sleeve; The locking ring cap is fitted over the locking sleeve and the locking ring, and engages with the locking sleeve. The locking ring cover is fitted over the locking ring and the locking ring cap, and limits the position of the locking ring cap.

4. The downhole throttle according to claim 3, characterized in that, The locking sleeve is provided with a spring claw at its distal end, and the inner surface of the middle sleeve of the retrieval assembly is provided with a groove, and the locking sleeve is limited to the groove by the spring claw. The locking sleeve has a first barb at its proximal end, and the locking ring cap has a second barb that matches the first barb. The locking ring cap engages with the locking sleeve.

5. The downhole throttle according to claim 2, characterized in that, The salvage assembly includes: a salvage sleeve, a salvage sleeve liner, a salvage shear pin holder, salvage shear pins, an intermediate sleeve, and a pressure cap; The retrieval sleeve liner is detachably connected to the central tube. The retrieval sleeve is fitted over the outside of the retrieval sleeve liner, and the retrieval sleeve can be limited by the proximal end of the retrieval sleeve liner. The salvage shear pin seat is sleeved on the salvage sleeve and is detachably connected to the proximal end of the salvage sleeve; The intermediate sleeve is fitted outside the retrieval shear pin seat and is limited by the retrieval shear pin. The intermediate sleeve is detachably connected to the slip seat. The pressure cap is fitted outside the retrieval sleeve and connected to the intermediate sleeve, and is used to limit the position of the retrieval shear nail seat.

6. The downhole throttle according to claim 5, characterized in that, The dispensing components include: a hand-dropping device and a hand-dropping nail clipper. The release head is nested inside the retrieval sleeve liner and is limited by the release shear nail.

7. The downhole throttle according to claim 2, characterized in that, Also includes: A connecting assembly and a sieve tube, the connecting assembly being used to connect the sieve tube to the proximal end of the central tube; The distal end of the screen tube abuts against the throttling assembly; The connecting assembly includes: a transfer sleeve, a lower connecting sleeve, a gasket, and a connecting cap; The intermediate sleeve and the lower connecting sleeve are sleeved outside the central tube and are detachably connected to the proximal end of the central tube. The distal end of the intermediate sleeve abuts against the locking ring cover of the locking assembly. The gasket is located between the intermediate sleeve and the lower connecting sleeve; The connecting cap is fitted over the locking ring cover and the transfer sleeve. The connecting cap is detachably connected to the locking ring cover and snaps into the transfer sleeve.

8. The downhole throttle according to claim 7, characterized in that, The screen tube is provided with at least two stages of foamed nickel-copper alloy filler, and the foamed nickel-copper alloy filler is configured with a porous structure.

9. A downhole throttling system, characterized in that, include: The delivery device and the downhole choke as described in any one of claims 1 to 8; The delivery device is used to set the downhole throttle in a preset position using the delivery component.

10. The system according to claim 9, characterized in that, Also includes: A retrieval device for unsealing and retrieving the downhole throttle via a retrieval assembly.

11. An oilfield gas production system, characterized in that, include: Tubing and downhole choke as described in any one of claims 1 to 8; The downhole throttle is used to be set at a preset position in the tubing to seal the tubing at the preset position.

12. The application of a downhole throttle as described in any one of claims 1 to 8 in an oilfield gas production system.

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