A downhole packer and method of forming a subsurface water circulation flow field based thereon

Abstract

The present application relates to a kind of well packer and the method for forming subterranean water circulation flow field based on it.The well packer includes center tube, packer assembly, drive assembly and positioning ring, packer assembly is set on center tube, can change the size of its cross-sectional area to change the contact state with circulation well wall;Drive assembly includes the power ring connected with one end of steel skeleton;Positioning ring includes first positioning ring and second positioning ring, the positioning ring is connected with center tube and is set on the two sides of power ring in a manner that can limit the deformation range of steel skeleton by limiting the activity range of power ring.The circulation method includes: setting well packer between pumping pipe and injection pipe;Corresponding to the depth of the position of the orifice of pumping pipe and injection pipe on the outer tube of circulation well, upper screen pipe and lower screen pipe are set respectively;At least part of drive assembly is driven by power or wireless signal to control packer assembly relative to center tube and expand its cross-sectional area to set packer circulation well.

Description

[0001] Case Analysis

[0002] The original basis for this divisional application is patent application No. 202210149092.4, filed on February 17, 2022, entitled "A packer inside a groundwater circulation well and its usage method". Technical Field

[0003] This invention relates to the field of groundwater circulation well repair technology devices, and more particularly to an in-well packer and a method for forming a groundwater circulation flow field based thereon. Background Technology

[0004] With the development of groundwater circulation well remediation technology in China, the research and development of packers within circulation wells has become a key issue in the practical application of this remediation technology. Packers, as downhole tools used to isolate different filter layers in the main wellbore of a circulation well for stratified water extraction and injection, are mainly used to isolate the extraction and injection sections. Fixed to the central pipe, their working pressure differs from the tens of megapascals of packers in oil wells; groundwater circulation well packers are typically designed for a low-pressure working environment of a few megapascals. Groundwater circulation well pipe diameters range from 300mm to 1200mm, requiring packers with larger setting diameters or expansion rates. Furthermore, multi-filter circulation wells in groundwater systems need to consider the simultaneous remediation of multiple contaminated aquifers, while current packers on the market generally only target a single treatment layer.

[0005] Currently, commonly used packers are mainly used in oilfield drilling engineering. They are connected to the downhole tubing string to seal the annular space between the tubing and the oil and gas well casing or open hole wall. They have high pressure resistance to adapt to the high-pressure environment of oil wells. However, commonly used packers have shortcomings such as many parts, time-consuming and labor-intensive production, which are not conducive to assembly and use. Some of them require the use of special unsealing tools to achieve unsealing. They also have disadvantages such as low working efficiency, complex structure, small applicable diameter, and cumbersome setting (unsealing) process, which makes them unsuitable for use in large-diameter groundwater circulation wells that require multiple filter layers for sealing.

[0006] Chinese patent CN213235011U discloses a self-sealing compression packer, including a hydraulic anchor, a central tube, and a lower connector. The hydraulic anchor is internally connected to the central tube via a thread. A back ring is fitted on the outer side of the lower end of the hydraulic anchor. A pressure transmission tube is provided between the back ring and the central tube, with through holes at both ends. A pressure transmission hole is provided on the back ring near the top of the pressure transmission tube. A rubber sleeve is fitted on the outer side of the pressure transmission tube near the lower end of the back ring. A hydraulic compensation piston is fitted on the lower end of the pressure bearing ring outside the pressure transmission tube. A pressure relief hole is provided on the top of the cup connecting sleeve. The boss of the locking ring cap is connected to the cup sealing skeleton through a pin. A cup compression sleeve is fitted on the outer side of the lower end of the cup. A ball seat is provided on the lower connector at the lower end of the central tube. A pressure guiding hole is provided on the side wall of the lower connector at the groove of the cup compression sleeve. The bottom end of the cup compression sleeve is connected to a guide ring through a shear pin. The packer designed in this patent can effectively prevent backflow and is easy to set. It is suitable for fracturing operations in horizontal wells, highly deviated wells, ultra-deep wells and shallow wells. However, the packer has many accessories, a complex structure, and is time-consuming, labor-intensive, and costly to produce in large quantities.

[0007] Chinese patent CN111894510A provides a combined rubber sleeve type two-stage ultra-high pressure sealing packer, mainly composed of a settling claw, locking device I, end rubber sleeve, spacer ring, middle rubber sleeve, locking device II, retaining ring, central tube, cone, and slips. The inner tube is threadedly connected to the upper connector and the settling claw; the outer shell connector is threadedly connected to outer shell I and outer shell II; outer shell III is located outside the settling claw; the settling claw is sleeved outside the settling short section; locking device I is located outside outer shell III; the locking seat is threadedly connected to the central tube; the end rubber sleeve, middle rubber sleeve, and spacer ring form a rubber sleeve assembly; the retaining ring is located between locking device II and the central tube; the slips are located between the cone and the slip platform and are fixed on the slip platform; the lower end of the central tube is threadedly connected to the slip platform and the lower connector. The packer designed in this patent is suitable for operation in ultra-high pressure environments and can effectively improve the sealing pressure and operational reliability of the packer. However, it cannot meet the operational requirements in environments with multiple aquifers. Furthermore, it requires a step-by-step unsealing process, involving setting down the short section and lifting the tubing string to lock it in place. Additionally, the slips will accumulate scale under long-term steam injection, leading to difficulties in unsealing and problems such as well sticking, resulting in unreliable performance. Moreover, due to the numerous components, the setting / unsealing operation is complex and involves many uncontrollable factors, which can easily cause packer setting / unsealing failure.

[0008] Chinese patent CN110847847A discloses a mechanically triggered packer with repeatable sealing and unlocking capabilities. It includes a central connecting tube, a fixed step and a locking assembly fixed to the central connecting tube. A triggering mechanism, a rib mechanism, and a spring assembly are also fitted onto the portion of the central connecting tube between the fixed step and the locking assembly. The fixed part of the triggering mechanism is connected to the fixed step, the telescopic end of the triggering mechanism is connected to one end of the rib mechanism, the other end of the rib mechanism is connected to one end of the spring assembly, and the other end of the spring assembly is connected to the locking assembly. A water-swellable rubber cylinder is integrally fitted onto the fixed step, triggering mechanism, rib mechanism, spring assembly, and locking assembly. However, in this invention, the triggering mechanism needs to directly contact the upper ring to open and close the rib structure. A positioning ring cannot be used to limit the expansion position between the triggering mechanism and the upper ring.

[0009] Therefore, in view of the many problems existing in the existing technology, it is necessary to set up a packer that can adapt to the working requirements of large-diameter wellbore and high expansion rate in groundwater circulation wells, and can also independently seal different screen sections of multi-filter circulation wells, and achieve the effect of simultaneous sealing / unsealing without mutual interference. Such a packer is simple to operate and does not occupy the space inside the well. Different packers can also be freely connected and combined through pumping and injection pipes and cables to achieve multi-segment sealing and precise control of unsealing as needed.

[0010] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this invention, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that the present invention does not possess the features of these prior art. On the contrary, the present invention already possesses all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Summary of the Invention

[0011] To address the shortcomings of existing technologies, this invention provides an in-well packer and a method for forming a groundwater circulation field based on it. The packer can electrically control the setting and unpacking processes. In practical applications, it can assist in independently sealing different sections of multi-filter circulating wells without being limited by unpacking and setting tools. It features a simple structure, stable performance, reusability, and rapid assembly and application. The setting (unpacking) operation is convenient, effectively improving production cycles and reducing costs. It is suitable for large-diameter wellbores and high expansion rates in groundwater circulating wells. The specific technical solution is as follows:

[0012] An in-well packer, mounted on a central tube, includes:

[0013] The packer assembly includes a steel frame capable of changing its cross-sectional area to alter the contact state between the surface rubber sleeve and the wellbore wall, and a drive assembly connected to the steel frame and, based on this connection, moving one end of the steel frame connected to the drive assembly along the central axis of the central tube. The steel frame deforms based on this movement, switching between setting and unsetting states. The steel frame itself has a simple structure, stable connection, and low usage and replacement costs. During the switching between setting and unsetting states, the steel frame changes its cross-sectional area due to its deformation, generating a thrust towards the surrounding wellbore wall. The magnitude of the thrust and the amount of change in cross-sectional area can be adaptively designed based on the actual size of the wellbore by changing the material and size of the steel frame. The elastic force generated by the deformation and compression of the steel frame is uniform and directionally stable. Within the elastic limit of the steel frame, repeated setting / unsetting will not cause excessive deformation of the steel frame or wear on the surface rubber sleeve material, enabling long-term stable use. Combined with the elasticity of the rubber sleeve, it provides good sealing, anti-pollution, and corrosion resistance. The effective contact area between the rubber sleeve and the wellbore wall is the main factor determining the sealing performance of the packer. The steel wires forming the steel skeleton are wrapped with rubber sleeves, ensuring that the steel skeleton remains straight and tightly fitted to the well wall after setting. The thrust of the drive assembly is also a crucial factor determining the packer's sealing performance. This packer uses sleeves on several evenly distributed steel wires to distribute the elastic force evenly, generating a uniform thrust independently in the circumferential direction, allowing the steel skeleton itself to withstand significant pressure. In the event of damage to a single steel wire, the elastic force of the surrounding wires provides compensation, temporarily supporting the damaged area, thereby reducing the risk of leakage and mitigating the impact of structural damage. Furthermore, the overall structure of the steel skeleton allows the steel wires to unseal even when exposed to moisture, preventing situations such as stuck wells and difficulty in retrieving the packer. This invention can also lengthen the steel wires to make the entire steel skeleton longer, allowing the rubber sleeve portion to fit more closely to the well wall, thus effectively improving the packing effect. Compared to most packers, this invention has fewer components, a shorter production and assembly cycle, and can be reused repeatedly, achieving high technological benefits at a lower cost. During use, this packer can quickly perform setting / unsetting operations and effectively avoid problems such as long replacement cycle of parts, stuck well, and unstable setting / unsetting process caused by many parts and complex principles.

[0014] According to a preferred embodiment, the drive assembly includes a power ring connected to one end of a steel frame, a transmission rod for driving the power ring to move, and a power unit. The power ring is movably sleeved on the first end of the central tube. The power unit is connected to the transmission rod in a manner that enables it to rotate around its own axis. The transmission rod is movably connected to the power ring in a manner that enables it to drive the power ring based on its own rotation. The thread angle of the transmission rod is set to 5°–8°, with a spacing of 1mm–3mm to prevent thread slippage. High-strength steel is used to manufacture the power transmission rod to withstand sufficient pressure and ensure stable operation under the setting condition.

[0015] The power unit and transmission rod move in a fixed position. Their movement based on their own axis rotation requires little space. When selecting a working environment, there is no need to consider the size of the working area. It can adapt to small spaces inside the well and multi-layer stacking operations.

[0016] According to a preferred embodiment, the packer assembly further includes a rubber sleeve covering the outer wall of the steel frame, capable of adapting to the deformation of the steel frame and thus deforming to contact the inner wall of the circulation well. Several steel wires forming the steel frame contact the rubber sleeve at uniform intervals and, upon deformation, uniformly push the rubber sleeve to deform and contact the well wall of the circulation well, achieving setting. That is, the shape formed by the deformation of the water-impermeable rubber sleeve effectively adheres to the well wall of the circulation well, separating the two sides of the circulation well from the point of contact. The material selected for the rubber sleeve has good physical and chemical stability, possesses a certain tensile strength to adapt to the setting / unsealing of the packer, and is resistant to pollution and acid / alkali corrosion, with a long service life. During use, it also effectively protects the steel wires, preventing them from being wetted and oxidized by moisture.

[0017] According to a preferred embodiment, the two ends of the rubber sleeve are connected to the base and the main board of the device, respectively. When the steel frame changes from the unsealed state to the set state, the steel frame slides relative to the inner wall of the rubber sleeve, at which time the rubber sleeve contacts the inner wall of the circulation well. When the rubber sleeve is not in contact with the movable end of the steel frame but in contact with the main board of the device, the rubber sleeve itself does not move with the movable end of the steel frame, but always maintains a constant relative position with the central tube. When the steel frame deforms and increases its cross-sectional area, the steel frame contacts the inner wall of the rubber sleeve when its cross-sectional area is greater than that of the rubber sleeve, and pushes the outer wall of the rubber sleeve closer to the circulation well and finally contacts the inner wall of the circulation well to achieve setting. The steel wires constituting the steel frame are wrapped with sleeves to limit the steel frame after setting to a straight and long shape that fits against the circulation well wall. During the setting process, the rubber sleeve will not rub against the circulation well wall as the steel frame moves relative to the central tube. By avoiding friction, the deformation of the steel frame can be expanded without easily damaging the rubber sleeve, thus ensuring the sealing performance of the packer.

[0018] According to a preferred embodiment, the packer in the groundwater circulation well further includes an elastic sheet layer. The elastic sheet layer is connected to a base and a main board at both ends. When the steel frame changes from an unsealed state to a seated state, the rubber sleeve slides relative to the inner wall of the elastic sheet layer. At this time, the elastic sheet layer contacts the inner wall of the circulation well to reduce wear on the rubber sleeve, thereby extending the service life of the packer and reducing its replacement frequency. The elastic sheet layer also ensures that the power ring, transmission rod, etc., are not wetted by water vapor, thus extending the static sealing time of the packer.

[0019] According to a preferred embodiment, the packer in the groundwater circulation well further includes positioning rings, comprising a first positioning ring and a second positioning ring. The first and second positioning rings are respectively positioned on both sides of the power ring and connected to the central tube, such that they limit the range of motion of the power ring and thus limit the deformation range of the steel frame. The positioning rings prevent the steel frame from losing its elasticity due to excessive deformation. The main board and base are placed in the recess of the central tube. The central tube, when spliced, limits the position of the main board and base, preventing the packer from sliding up and down.

[0020] According to a preferred embodiment, the base is connected to the second positioning ring via a fixing rod in a manner that increases the stability of the in-well packer.

[0021] According to a preferred embodiment, one end of the transmission rod relative to the power unit is movably connected to the second positioning ring in a manner that can increase the stability of the in-well packer.

[0022] According to a preferred embodiment, the steel frame is configured to consist of several steel wires arranged alternately with their directions aligned with the central axis of the central tube, and the contact between the steel wires and the rubber sleeve is intermittent. The sleeve covering the surface of the steel wires ensures that the steel frame remains straight and fitted against the well wall of the circulation well after the sealing is initiated; multiple sets of steel wires provide greater stability under high pressure, and can also withstand damage to a single steel wire for a longer period due to their own elasticity. This configuration effectively ensures the sealing effect.

[0023] The present invention also provides a method for using an in-well packer as described above, comprising the following steps:

[0024] S1. Place the packer inside the well into the part of the circulation well that needs to be sealed, and position it so that the axis of the central tube is parallel to the axis of the circulation well.

[0025] S2 controls the power unit to drive the transmission rod to rotate in a third direction, so that the steel frame deforms under the drive of the power ring to increase its cross-sectional area and increase the contact area between the rubber sleeve and the inner wall of the circulation well to enter the setting and sealing state;

[0026] When unsealing is required, S3 controls the power unit to drive the transmission rod to rotate in the fourth direction opposite to the third direction, so that the steel frame recovers its deformation under the drive of the power ring to reduce its cross-sectional area and reduce the contact area between the rubber sleeve and the inner wall of the circulation well to enter the unsealing state.

[0027] In another aspect, this invention provides a packer method for circulating wells. A driving component drives at least a portion of the packer assembly to move relative to the central tube along a first direction, causing the packer assembly to deform and expand its cross-sectional area, thus contacting the circulating well wall and achieving setting. The driving component then drives at least a portion of the packer assembly to move relative to the central tube along a second direction opposite to the first direction, causing the packer assembly to recover its deformation, reduce its cross-sectional area, and disengage from the circulating well wall, thus achieving unsealing. The packer of this invention has the following advantages:

[0028] (1) The packer is a purely mechanical structure. The packer is deformed by the electric drive component, which reduces the probability of control failure. At the same time, the structure is simple and the assembly is easy.

[0029] (2) The drive components can be controlled by electrical or wireless signals. The setting and unsetting processes do not require additional accessories to be installed in the well. Multiple packers in multi-filter circulating wells can be set / unset simultaneously without affecting each other.

[0030] (3) The components of the enclosure are simple in structure and the materials are resistant to pollution and corrosion, and can be recycled multiple times, with low assembly and maintenance costs;

[0031] (4) The packer can be completely installed in the circulation well without downhole assembly. It has a small range of movement during operation, occupies less space, and leaves more reaction space in the circulation well.

[0032] Another aspect of the present invention provides a method for driving the vertical circulation of groundwater in an aquifer surrounding a circulating well, comprising the following steps:

[0033] S1 has pumping pipes and injection pipes installed at different depths inside the well, and the packer inside the well is installed between the pumping pipes and the injection pipes;

[0034] S2 has screens installed on the well body of the circulation well at the depth positions corresponding to the inlets of the pumping pipe and the injection pipe to facilitate the inflow or outflow of groundwater in the well.

[0035] S3 controls the electric drive assembly via electrical or wireless signals to move at least a portion of the packer assembly relative to the central tube and expand its cross-sectional area to set the circulating well.

[0036] S4 initiates water injection, thereby driving the groundwater in the aquifers surrounding different screen sections to form a vertical circulating flow field.

[0037] The advantages of this setup are: the ability to control the unsealing and setting status of the packers in the well via electric or wireless signals, and the relatively small size of the packers, facilitates precise control of the stacking of multiple packers in the same circulation well, thereby enabling the formation of multiple vertical water circulation units in different aquifers according to the needs of repair. Attached Figure Description

[0038] Figure 1 This is a schematic diagram illustrating the application of the present invention to the sealing of groundwater circulation wells;

[0039] Figure 2 This is a schematic diagram of the steel frame structure without the plastic tube covering when the device is unsealed according to the present invention;

[0040] Figure 3 This is a schematic diagram of the steel frame encasing the rubber tube structure during unsealing of the present invention;

[0041] Figure 4 This is a schematic diagram of the steel frame structure without the rubber cylinder covering during the setting process of this invention;

[0042] Figure 5 This is a cross-sectional schematic diagram of the power ring, protective ring, and second positioning ring of the present invention;

[0043] Figure 6 This is a schematic diagram of the driving component structure of the present invention.

[0044] List of reference numerals

[0045] 1: Central tube; 2: Base; 3: Steel frame; 301: Steel wire; 4: Rubber tube; 5: Sealing ring; 6: Positioning ring; 601: First positioning ring; 602: Second positioning ring; 7: Drive assembly; 701: Transmission rod; 702: Power unit; 703: Power ring; 8: Second thread; 9: Nut; 10: Elastic element; 11: Protective ring; 12: Fixing rod; 13: Upper screen tube; 14: Lower screen tube; 15: Pumping pipe; 16: Injection pipe; 17: Sleeve. Detailed Implementation

[0046] The following is in conjunction with the appendix Figure 1-6 Please provide a detailed explanation.

[0047] Example 1

[0048] This embodiment provides an in-well packer that can isolate the stratified pumping and injection areas within a circulating well by adhering to the well wall. The packer includes at least a central pipe 1 for the passage of cables and pipes, a base 2 surrounding the outer wall of the central pipe 1, and a packing assembly capable of changing its cross-sectional area to alter its contact with the well wall. Preferably, the central pipe 1 has a first end and a second end, the base 2 is disposed at the first end of the central pipe, and the packing assembly includes at least a steel frame 3 and a rubber sleeve 4 that change their volume to alter the contact area with the well wall, thereby changing the connectivity of the circulating well. The steel frame 3 is a cylindrical shape with both ends facing the central pipe and capable of deformation. Preferably, the steel frame 3 is composed of several steel wires 301 arranged neatly. Each steel wire can generate a thrust in all directions based on its own elasticity, pushing the rubber sleeve 4, which covers the cylindrical steel frame 3, to deform and adhere to the well wall. Preferably, the steel frame 3 is configured to deform to change its cross-sectional area and its contact area with the well wall. Preferably, the rubber sleeve 4 is designed to undergo elastic deformation, adapting to the shape change of the steel frame 3 when the steel frame 3 deforms. Preferably, the rubber sleeve 4, under the pressure generated after the steel frame 3 deforms, makes tight contact with the well wall of the circulation well, achieving sealing of the circulation well. Preferably, the surface of the steel wire 301 is wrapped with a sleeve 17 to constrain the steel frame 3 to be straight and elongated and fit against the well wall of the circulation well during the setting process, thereby effectively ensuring the sealing effect. Preferably, the interior of the central tube 1 is designed as a hollow honeycomb structure to allow the passage of necessary components such as cables or pipes. Preferably, a sealing ring 5 is provided on the outer wall of the base 2.

[0049] According to a preferred embodiment, the sealing assembly further includes a drive assembly 7 for controlling whether the steel frame 3 deforms and the magnitude of the deformation. The drive assembly 7 includes a transmission rod 701, a power unit 702, and a power ring 703. Preferably, the power ring 703 is disposed at the second end of the central tube 1 and is movably sleeved on the central tube 1. Preferably, the plurality of steel wires 301 constituting the steel frame 3 each have a third end and a fourth end. The third end of the steel wires 301 is connected to the power ring 703, and the fourth end of the steel wires 301 is connected to the base 2. Preferably, the third ends of the plurality of steel wires 301 are connected to the outer periphery of the power ring 703. Preferably, the plurality of steel wires 301 are evenly spaced. Preferably, at least one inner ring with an axis substantially parallel to the axis of the central tube 1 is also provided inside the power ring 703. Preferably, a nut 9 is fixedly connected to the inner ring, and a first thread is provided on the inner wall of the nut 9. The transmission rod 701 includes a fifth end and a sixth end. The fifth end of the transmission rod 701 is inserted into the inner ring and abuts against the inner wall of the inner ring or against the inner wall of the nut 9, and is linked based on the abutment. Preferably, the transmission rod 701 is provided with a second thread 8 that engages with a first thread on the inner wall of the inner ring. When the transmission rod 701 rotates, the power ring 703 can move relative to the transmission rod 701 in the axial direction of the transmission rod 701 based on the presence of the engaging first thread and second thread 8. Preferably, the angle of the second thread 8 of the transmission rod 701 is set to 5° to 8°, and the spacing is 1mm to 3mm to prevent thread slippage. High-strength steel is selected as the raw material for the transmission rod 701 to withstand pressure and ensure stable operation under the setting condition. Preferably, at least two inner rings are symmetrically arranged relative to the center of the power ring 703, so that the power ring 703 can move stably along the axial direction of the transmission rod 701 when the transmission rod 701 rotates, without causing abnormal deformation of the steel wire 301 connected to it due to deflection, thus affecting the sealing effect of the packer in the well. Preferably, the sixth end of the transmission rod 701 is connected to the power unit 702. The power unit 702 can drive the transmission rod 701 to rotate along its own axis in a third or fourth direction opposite to each other based on externally supplied electrical energy or other control, thereby driving the power ring 703 to move along the axial direction of the transmission rod 701, thereby causing the steel frame 3 to deform or recover its deformation, completing the setting and unsealing movements. Preferably, the power unit 702 is rotatably connected to the sixth end of the transmission rod 701, for example, through a gear connection. When the two transmission rods 701, which connect the two inner rings respectively, rotate around their own axes driven by the power unit 702, they adjust their rotation direction according to their own thread direction and the direction of the thread on the inner ring that meshes with their own thread. This ensures that when both transmission rods 701 rotate simultaneously, they control the power ring 703 to move in the same direction, either upwards or downwards. Preferably, the packer also includes a main board, which is located on the second end of the central tube 1.Preferably, the main board is located on the side of the power ring 703 near the second end of the central tube 1. Preferably, a sealing ring 5 is provided on the outer side of the power ring 703. Preferably, the main board and the base 2 are placed at the recess of the central tube 1, and after being spliced ​​with the central tube 1, the positions of the main board and the base 2 can be limited, thereby preventing the packer from sliding up and down as a whole, and enabling the packer to operate stably.

[0050] According to a preferred embodiment, the packer of this embodiment further includes a positioning ring 6, which is used to limit the distance the power ring 703 moves along the axial direction of the transmission rod 701. The positioning ring 6 includes at least a first positioning ring 601 and a second positioning ring 602 coaxially disposed on the central tube 1. The first positioning ring 601 and the second positioning ring 602 are respectively disposed on both sides of the power ring 703 to limit the distance the power ring 703 moves along the axial direction of the transmission rod 701 between the first positioning ring 601 and the second positioning ring 602, thereby defining the setting and unsetting positions of the power ring 703, while avoiding excessive stretching of the steel wire, reasonably controlling the elastic deformation of the steel frame 3, and extending the service life of the packer. Preferably, the first positioning ring 601 is disposed between the main board of the device and the power ring 703.

[0051] Preferably, the fifth end of the transmission rod 701 connects to the inner ring, passing through the inner ring and movably connected to the second positioning ring 602. Preferably, the fifth end of the transmission rod 701 is connected to the second positioning ring 602 via a bearing. Preferably, the second positioning ring 602 is also connected to a protective ring 11 via an elastic element 10. At least two elastic elements 10 are evenly disposed between the second positioning ring 602 and the protective ring 11, so that when the power ring 703 moves to the point of contacting the second positioning ring 602, it can first contact the protective ring 11 and generate a buffering effect due to the presence of the elastic elements 10, while avoiding impact on the second positioning ring 602 when the power ring 703 moves too fast, thereby shortening the service life of the power ring 703 or the second positioning ring 602. Preferably, the elastic element 10 can be implemented as a spring. Preferably, the second positioning ring 602 and the base 2 are connected by at least two fixed rods 12, so that the second positioning ring 602 and the base 2 can support each other when necessary.

[0052] For ease of understanding, the working principle of the packer provided in this embodiment is described below:

[0053] Setting process: The control power unit 702 drives the transmission rod 701 to rotate in a third direction. The transmission rod 701, based on the first and second threads 8 that are in contact with each other, drives the power ring 703 to move towards the second positioning ring 602, thereby causing the steel frame 3 to deform and expand elastically as a whole. This increases the cross-sectional area of ​​the steel frame 3, and the contact area between the rubber sleeve 4 covering the outside of the steel frame 3 and the inner wall of the circulation well gradually increases. When the power ring 703 moves to indirectly contact the second positioning ring 602 through the protective ring 11 and the elastic element 10 is fully compressed, the contact area between the rubber sleeve 4 and the well wall of the circulation well is at its maximum. At this time, the control power unit 702 stops rotating, the packer completes the setting process, and remains in this setting state.

[0054] Unsealing process: The control power unit 702 drives the transmission rod 701 to rotate in a fourth direction opposite to the third direction. The transmission rod 701, based on the mutually abutting first and second threads 8, drives the power ring 703 to move towards the first positioning ring 601, thereby causing the steel frame 3 to gradually recover its deformation. The cross-sectional area of ​​the steel frame 3 gradually decreases, and the contact area between the rubber sleeve 4 and the inner wall of the circulation well gradually decreases. When the power ring 703 moves to contact the first positioning ring 601, the contact area between the rubber sleeve 4 and the inner wall of the circulation well is at its minimum, or even non-contact. At this point, the control power unit 702 stops rotating, thus completing the unsealing process of the packer and maintaining it in this unsealed state.

[0055] Example 2

[0056] This embodiment provides a method for recycling groundwater using a packer as described in Embodiment 1, including the following steps:

[0057] S1 Place the packer inside the well into the part of the circulation well that needs to be sealed, and position it so that the axis of the central pipe 1 is parallel to the axis of the circulation well.

[0058] S2 controls the power unit 702 to drive the transmission rod 701 to rotate in a third direction, so that the steel frame 3 deforms under the drive of the power ring 703, increases its cross-sectional area and increases the contact area between the rubber sleeve 4 and the inner wall of the circulation well to enter the setting and sealing state.

[0059] When unsealing is required, S3 controls the power unit 702 to drive the transmission rod 701 to rotate in the fourth direction opposite to the third direction, so that the steel frame 3 can recover its deformation under the drive of the power ring 703, reduce its cross-sectional area, and reduce the contact area between the rubber sleeve 4 and the inner wall of the circulation well, thus entering the unsealing state.

[0060] Example 3

[0061] A method for driving the vertical circulation of groundwater includes the following steps:

[0062] S1 is equipped with a pumping pipe 15 and an injection pipe 16 inside the well. The specific locations are determined based on the actual conditions of the circulation well.

[0063] S2 has an upper screen pipe 13 and a lower screen pipe 14 installed on the outer pipe of the circulation well at the depth positions corresponding to the inlets of the pumping pipe and the injection pipe, respectively.

[0064] When the packer in the well is in the set state, the water pump is turned on to inject water, thereby driving the groundwater in the aquifer around the circulating well to circulate vertically.

[0065] Example 4

[0066] This embodiment is a further improvement and supplement to Embodiment 1, and repeated content will not be described again.

[0067] According to a preferred embodiment, an elastic sheet is further provided on the outer side of the base 2 and the main board of the device. The elastic sheet covers the outer side of the rubber cylinder 4, with one end connected to the outer periphery of the base 2 and the other end connected to the outer side of the main board of the device. Preferably, the elastic sheet can also undergo elastic deformation. During setting, the steel frame 3 deforms and increases its cross-sectional area, thereby supporting the rubber cylinder 4 to undergo elastic deformation and pushing the rubber cylinder 4 outward, so that the rubber cylinder 4 contacts the inner wall of the elastic sheet. At the same time, the rubber cylinder 4 pushes the outer wall of the elastic sheet to contact the well wall of the circulation well. This arrangement is beneficial because when the steel frame 3 and the rubber cylinder 4 move for setting and unsetting, the rubber cylinder 4 contacts the inner wall of the elastic sheet and not the rough inner wall of the circulation well, thus preventing the rubber cylinder 4 from being scratched by burrs during setting and unsetting, and avoiding affecting the setting effect. Meanwhile, since the positions of the base 2 and the main board of the device remain unchanged throughout the entire setting process, the relative position of the outer wall of the elastic sheet and the inner wall of the circulation well remains unchanged. The elastic sheet will not rub against or slide relative to the inner wall of the circulation well, thus preventing the elastic sheet from being scratched.

[0068] According to a preferred embodiment, the rubber sleeve 4 has a seventh end and an eighth end. The seventh end of the rubber sleeve 4 is connected to the circumferential direction of the base 2, and the eighth end of the rubber sleeve 4 is connected to the circumferential direction of the main board of the device. Preferably, the diameters of the base 2 and the main board of the device are smaller than the diameter of the circulation well and smaller than the maximum cross-sectional area of ​​the steel frame 3 after deformation. During the setting process, by controlling the deformation of the steel frame 3 to increase its cross-sectional area, the steel wires 301 that make up the steel frame 3 push the rubber sleeve 4 in a direction away from the central pipe axis, causing the rubber sleeve 4 to undergo elastic deformation and contact the inner wall of the circulation well. This arrangement helps prevent the rubber sleeve 4 from rubbing against the inner wall of the circulation well during setting and unsetting, thus preventing the rubber sleeve 4 from being scratched or worn, while reducing the failure rate of the packer and extending its service life.

[0069] According to a preferred embodiment, the steel wires 301 constituting the steel frame 3 are wrapped with sleeves 17, thereby ensuring that the steel frame 3 is straight and long and fits against the well wall of the circulation well after setting. By limiting the shape of the steel wires 301, the deformation of the rubber sleeve 4 can be pushed to fit the shape of the inner wall of the circulation well, increasing the sealing effect of the packer. This packer uses the sleeves 17 on several steel wires 301 to evenly distribute the elastic force, independently generating uniform thrust in the circumferential direction, so that the steel frame 3 itself can withstand greater pressure. In the event of damage to a single steel wire 301, the surrounding steel wires 301 can provide elastic compensation and temporarily provide support for the damaged area, thereby reducing the risk of leakage and mitigating the impact of structural damage.

[0070] It should be noted that the specific embodiments described above are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this invention, and these solutions all fall within the scope of this invention and its protection. Those skilled in the art should understand that this specification and its accompanying drawings are illustrative and do not constitute a limitation on the claims. The scope of protection of this invention is defined by the claims and their equivalents. This specification contains multiple inventive concepts; terms such as "preferredly," "according to a preferred embodiment," or "optionally" indicate that the corresponding paragraph discloses an independent concept. The applicant reserves the right to file divisional applications based on each inventive concept. Throughout the text, features introduced by "preferredly" are merely optional and should not be construed as mandatory. Therefore, the applicant reserves the right to abandon or delete relevant preferred features at any time.

Claims

1. A packer installed in a well, disposed on a central tube (1), characterized in that, include: The power ring (703) has at least one inner ring whose axis is parallel to the axis of the central tube (1). The inner ring is fixedly connected to a nut (9). The inner wall of the nut (9) is provided with a first thread. The transmission rod (701) includes a fifth end and a sixth end. The fifth end of the transmission rod (701) is inserted into the inner ring and abuts against the inner wall of the inner ring or against the inner wall of the nut (9) and is linked based on the abutment. The transmission rod (701) is provided with a second thread (8) that matches the first thread on the inner wall of the nut (9) that is fixedly connected to the inner ring. When the transmission rod (701) rotates, it can drive the power ring (703) to move relative to the transmission rod (701) in the axial direction of the transmission rod (701) based on the presence of the first thread and the second thread (8) that match each other. It also includes a positioning ring (6) and a steel frame (3). The positioning ring (6) includes a first positioning ring (601) and a second positioning ring (602). The first positioning ring (601) and the second positioning ring (602) are respectively connected to the central tube (1) and set on both sides of the power ring (703) in such a way that the deformation range of the steel frame (3) can be limited by limiting the range of motion of the power ring (703). The central tube (1) is equipped with a base (2) and a main board at both ends. The end of the steel frame (3) facing away from the power ring (703) is connected to the base (2). The main board is located on the side of the first positioning ring (601) away from the power ring (703). The main board and the base (2) are placed at the indentation of the central tube (1). After the central tube (1) is spliced, it can limit the position of the main board and the base (2) to prevent the packer from sliding up and down. The steel frame (3) is formed by several steel wires arranged circumferentially around the central axis of the central tube (1). The surface of the steel wires is wrapped with a sleeve to limit the steel frame (3) after the start-up and setting. It is straight and long and fits against the well wall of the circulation well.

2. The packer according to claim 1, characterized in that, include: The packing assembly, including a steel frame (3), is capable of changing its cross-sectional area to alter its contact state with the wellbore of the circulation well. The drive assembly (7) includes a power ring (703) connected to one end of the steel frame (3).

3. The packer according to claim 2, characterized in that, The drive assembly (7) further includes a transmission rod (701) and a power unit (702) for driving the power ring (703) to move; the drive assembly (7) is connected to the steel frame (3) and drives one end of the steel frame (3) connected to the drive assembly (7) to move along the central axis of the central tube (1) based on the connection, and the steel frame (3) deforms based on the movement and switches between the sealing and unsealing states.

4. The packer according to claim 3, characterized in that, The power ring (703) is movably sleeved on the first end of the central tube (1). The power unit (702) is connected to the transmission rod (701) in a manner that can drive the transmission rod (701) to rotate. The transmission rod (701) is connected to the power ring (703) in a manner that can drive the power ring (703) to move up and down along the central tube (1) based on its rotation.

5. The packer according to claim 2, characterized in that, The sealing assembly also includes a rubber sleeve (4) that covers the outer wall of the steel frame (3), is able to adapt to the deformation of the steel frame (3) and thus deform and contact the inner wall of the circulation well to seal the circulation well.

6. The packer according to claim 1, characterized in that, The second positioning ring (602) is connected to a protective ring (11) via an elastic element (10). The protective ring (11) is positioned on the side close to the power ring (703) in such a way that it can provide a buffer when the power ring (703) moves along the central tube (1) and comes into contact with the second positioning ring (602).

7. A groundwater circulation method with a sealed circulating well, characterized in that, Use the in-well packer as described in any one of claims 1 to 6 for circulating well packing.

8. The cyclic method according to claim 7, characterized in that, Includes the following steps: Place the packer into the part of the circulation well that needs to be sealed, and position it so that the axis of the central tube (1) is parallel to the axis of the circulation well. The control power unit (702) drives the transmission rod (701) to rotate in the third direction, so that the steel frame (3) deforms under the drive of the power ring (703) to increase its cross-sectional area and increase the contact area between the rubber sleeve (4) and the inner wall of the circulation well, thus entering the set-sealing state. When unsealing is required, the power unit (702) is controlled to drive the transmission rod (701) to rotate in the fourth direction opposite to the third direction, so that the steel frame (3) recovers its deformation under the drive of the power ring (703) to reduce its cross-sectional area and reduce the contact area between the rubber cylinder (4) and the inner wall of the circulation well, thus entering the unsealing state.

9. The cyclic method according to claim 7 or 8, characterized in that, Includes the following steps: A pumping pipe (15) and an injection pipe (16) are installed inside the well, and a packer is installed between the pumping pipe (15) and the injection pipe (16). An upper screen pipe (13) and a lower screen pipe (14) are respectively installed on the outer pipe of the circulation well at the depth positions corresponding to the inlets of the pumping pipe (15) and the injection pipe (16). The drive assembly (7) is controlled by electric or wireless signals to move at least a portion of the packer assembly relative to the central tube (1) and expand its cross-sectional area to set the circulation well. The water pump is turned on to inject water, which in turn drives the groundwater in the aquifer around the circulation well to circulate vertically.

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