Underground cavitation water jet unblocking device

Abstract

The utility model relates to an underground cavitation water jet unblocking device, which comprises a jet packer and an eccentric pulse supercharger, the jet packer is connected with a crossover coupling among a packer upper joint, an upper central pipe and a leather cup inner pipe, and the crossover coupling and the upper central pipe are respectively provided with an overflow hole I; an overflow hole II and an overflow hole III are respectively formed in an eccentric cylinder and a lining pipe in the eccentric pulse supercharger; the upper central pipe is connected with the lower central pipe, and a cavitation water jet device provided with a cavitation nozzle is connected outside the lower central pipe between the jet packer and the eccentric pulse supercharger; a blocking ring is arranged at the lower end of the annulus of the cavitation water jet device and the lower center pipe, and a high-pressure jet annulus communicated with the overflowing hole is formed. The device has multiple effects of low-frequency hydraulic impact, cavitation entrainment, rotary shearing and vibration loosening of blockages, the cavitation effect is amplified through gas-mixed water excitation, the gas lift flowback effect of low-density gas-mixed water is better facilitated, and the blockage removal effect is remarkable.

Description

Technical Field

[0001] The utility model relates to a tool for removing blockage in oil layers in oil wells of oil fields, in particular to an underground cavitation water jetting blockage removing device. Background Art

[0002] With the continuous development of oil fields, especially after entering the high water-cut development stage, under the limited ground conditions and investment, side drilling has become an important means of improving the well network, updating oil and water wells, treating casing damaged wells, and tapping potential and increasing efficiency in the mid-to-late development of oil fields.

[0003] Currently, blockages and deposits in horizontal wells and sidetracked horizontal wells primarily occur due to the absorption, deposition, bonding, and agglomeration of clay, colloid, and fine sand within screen crevices and between the base pipe and the filter sand layer. The primary cause of blockage is the filling of sand and mud between sand grains within the gravel pack outside the screen. The main blockages are classified as drilling mud, muddy fine sand, and a mixture of oil, mud, and sand.

[0004] The completion method of small-casing sidetracked horizontal wells, usually with casing inner diameters of 4″ and 4 1 / 2″, is limited by the smaller wellbore and casing inner diameter. The degree of contamination in the wells is often higher than that of conventional non-sidetracked wells. They are also more prone to blockage during the development process, resulting in a decrease in fluid production.

[0005] According to the different types of blockages in the formation, the currently used unblocking technologies can be divided into two categories: the first is chemical unblocking, which is to inject various chemical unblocking agents, surfactants, organic solvents, etc. into the formation to remove the blockage, reduce surface tension, and increase crude oil production. Although this method is effective, it is costly and prone to secondary contamination of the formation. The second is physical unblocking, which is to use the energy of various shock and vibration waves to loosen and fall off the formation blockage, remove the blockage, and restore the permeability of the formation. At the same time, the effects of vibration and shock waves can reduce the viscosity and surface tension of crude oil, improve crude oil fluidity, and thus increase oil production. As a new technology for enhancing oil recovery, increasing production and injection, physical methods of treating formations are simple, easy, low-cost, and have no secondary pollution. Therefore, they are increasingly valued and welcomed by production site technicians.

[0006] Existing plugging removal technologies are primarily suitable for casings 5 ​​1 / 2″ and larger. For horizontal wells with small casing sidetracking, with an inner diameter of 4″ and 4 1 / 2″, the development of tools and tools for such applications is still in the early stages of exploration and research, with no mature and comprehensive supporting plugging removal technology yet to be developed. Therefore, a plugging removal device applicable to horizontal wells with small casing sidetracking is urgently needed.

[0007] In order to solve the above problems, the following related patent technologies have emerged: Chinese patent application No. 201220528986.6 discloses a high-pressure jet and negative pressure suction unblocking device, which includes a negative pressure suction return unblocking device, an oil drain, a one-way valve, a rotating connection device, and a self-rotating ejector connected in sequence from top to bottom. The self-rotating ejector of the device is equipped with an oblique nozzle. After the high-pressure water flow sprayed by the oblique nozzle reaches the unblocking part, it will produce a tangential force for peeling off the blockage. At the same time, the self-rotating ejector can also rotate while spraying water, so that the water flow produces impact fatigue on the unblocking part, making the blockage easier to loosen and detach. After the high-pressure water jet unblocks, the device uses negative pressure suction to discharge impurities from the ground to solve the oil layer pollution blockage.

[0008] However, the above utility model cannot be used in small casing sidetracking horizontal wells.

[0009] Chinese patent application No. 201520262595.8 discloses a rotary water jet unblocking device, comprising: a multi-stage filter, a bypass valve, a centralizer, a rotation speed controller and a nozzle connected in sequence, and also comprising: a two-ball separation joint connected to the multi-stage filter at one end and to the pipe column at the other end, for installing a two-ball separation component; a two-ball separation component provided inside the two-ball separation joint, for separating a large ball and a small ball that close the bypass valve.

[0010] The above-mentioned utility model can reduce the risk of misplaced ball delivery in horizontal wells, increase pumping and delivery speed, and improve operational efficiency. However, the utility model requires the delivery of two steel balls of different sizes, which carries the risk of misplaced balls, is cumbersome to operate, and cannot be used in small-casing sidetracking wells or horizontal wells.

[0011] Chinese patent application number CN202122654792.2 discloses a cavitation jet generating device and cleaning equipment, which includes a cavitation nozzle and an ultrasonic actuator. The cavitation nozzle includes a nozzle body and an outlet end cap, and the nozzle body is provided with a composite cavity, a resonance cavity and a water outlet along its axial direction. The aperture of the composite cavity in the stepped hole is larger than the resonance cavity, and the aperture of the resonance cavity is larger than the water outlet. The outlet end of the nozzle body is fixedly provided with the outlet end cap. The ultrasonic actuator is fixedly connected to the composite cavity end of the nozzle body. The outer wall of the composite cavity of the nozzle body is provided with a water injection hole connected to the composite cavity. This utility model significantly enhances the erosion and cleaning ability of the jet and increases the effective range of the jet. It also improves the transmission efficiency of acoustic vibration in different media, improves the energy utilization rate of the jet, and reduces the dependence of the cavitation jet effect on the installation accuracy of the ultrasonic actuator.

[0012] However, the above device is an ultrasonic pulse water jet pipe wall rust removal and cleaning device, which is not suitable for flushing downhole sediment blockages and unblocking formations in horizontal wells and side-drilled horizontal wells. Summary of the Invention

[0013] The purpose of this utility model is to address the above-mentioned defects and provide a downhole cavitation water jet unblocking device, which has the functions of high-pressure jet, air-water resonance and negative pressure suction, and can be applied to horizontal wells and side-drilled horizontal wells to solve the problem of oil layer blockage for horizontal wells and side-drilled horizontal wells, increase the production of horizontal wells and side-drilled horizontal wells, and improve economic benefits.

[0014] The technical solution of the utility model is: a downhole cavitation water jet unblocking device, including a jet packer and an eccentric pulse booster, wherein: the jet packer is connected with a conversion joint between the upper joint of the packer and the upper center pipe and the inner pipe of the leather cup, and the conversion joint and the upper center pipe are both provided with a flow hole 1; the eccentric cylinder and the inner liner pipe in the eccentric pulse booster are respectively provided with a flow hole 2 and a flow hole 3; the upper center pipe is connected to the lower center pipe, and a cavitation water jet equipped with a cavitation nozzle is connected to the outside of the lower center pipe between the jet packer and the eccentric pulse booster; a blocking ring is provided at the lower end of the annulus between the cavitation water jet and the lower center pipe to form a high-pressure jet annulus connected to the flow hole.

[0015] Preferably, more than one cavitation water jet is connected between the jet packer and the eccentric pulse intensifier; the number of the connected cavitation water jets is determined according to the thickness of the oil layer; and the cavitation water jets are connected by threads.

[0016] Preferably, the eccentric pulse supercharger is provided with an eccentric cylinder, an inner liner, an upper supercharger joint and a lower supercharger joint. An eccentric cylinder of one level or more is connected to the outside of the inner liner. The eccentric cylinders are connected by a connecting ring, and an adsorption annulus is formed between the eccentric cylinder and the inner liner on both sides of the connecting ring; the upper supercharger joint and the lower supercharger joint connected to the two ends of the inner liner are respectively threadedly connected to the cavitation water jet and the cannula; a set screw three and a set screw two or four are respectively installed between the upper supercharger joint and the lower supercharger joint and the inner liner, and the lower supercharger joint can be threadedly connected to the cannula.

[0017] Preferably, the shell of the cavitation water jet is a cylindrical body, and the inner circle of the upper end and the outer circle of the lower end are respectively provided with internal threads and external threads, and the cavitation nozzle is installed in a cavitation nozzle cavity provided in the shell.

[0018] Preferably, the cavitation nozzle cavity is a multi-step installation cavity that is radially connected to the housing and is provided with a threaded connection cavity. The cavitation nozzle cavity is evenly distributed and obliquely arranged in the housing.

[0019] Preferably, more than two rows of cavitation nozzle cavities are provided in the axial direction of the shell, and more than three cavitation nozzle cavities are provided in each row in the circumferential direction of the shell.

[0020] Preferably, the cavitation nozzle installed in the cavitation nozzle cavity is a non-uniform hollow cylinder and is provided with a jet hole, a mounting head, a cavitation injection cavity and a sealing section; the jet hole is connected to the cavitation injection cavity, and the maximum outer diameter section in the cavitation nozzle is provided with an external thread and can be threadedly connected to the threaded connection cavity in the cavitation nozzle cavity.

[0021] Preferably, the jet hole is a tapered hole connected to the cavitation injection chamber and is small inside and large outside; the outer wall of the mounting head is provided with a wrench square that matches the inner tube wrench; the sealing section is provided with a sealing ring groove and a sealing ring is installed in the sealing ring groove.

[0022] Preferably, both ends of the conversion joint are provided with internal threads and are respectively threadedly connected to the upper joint of the packer and the inner tube of the leather cup, and there is more than one set screw in the threaded connection section with the inner tube of the leather cup; the flow hole is provided in the non-threaded connection section of the conversion joint, and the flow holes in the conversion joint and the upper center pipe are both provided with more than two; the conversion joint is connected between the upper leather bowl in the jet packer and the upper joint of the packer, so that the flow hole is located above the upper leather bowl.

[0023] Preferably, the internal thread in the upper inner cavity of the upper joint of the packer is an oil pipe thread and can be connected to the oil pipe thread, and the internal thread and external thread of the lower part of the upper joint of the packer are respectively threadedly connected to the upper center pipe and the conversion joint; and one or more set screws 2 are also installed in the threaded connection section between the leather cup inner tube and the lower joint of the packer.

[0024] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention is a physical unblocking method that utilizes a cavitation water jet to generate high-pressure water jets, high-frequency oscillating hydraulic waves, and cavitation noise (ultrasonic waves) to directly flush downhole sand control pipes.

[0025] 2. Based on the conventional unblocking technology, the utility model adds a cavitation water jet with rotating jet, air-water resonance and negative pressure suction to the characteristics of sand production in muddy cemented loose sandstone and oil well blockage. It can not only remove surface blockage but also dredge blockage of near-well sediments, greatly improving the effect of unblocking, increasing production and injection.

[0026] 3. This utility model utilizes multiple mechanisms to loosen blockages, including low-frequency hydraulic impact, cavitation entrainment, rotary shear, and vibration. The aerated water excitation amplifies the cavitation effect and further facilitates the gas lift and flowback of the low-density aerated water. For wells with severe blockages, the aerated water can be replaced with a chemical aerated declogging fluid to soak and drive the blockage, achieving even better results.

[0027] 4. The utility model has a wide range of applications and can be used to remove blockage in oil layers in horizontal wells with small casing side drilling.

[0028] In summary, the utility model has significant use effects and can produce good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a structural diagram of the utility model; Figure 2 for Figure 1 AA view in; Figure 3 for Figure 1 The front view of the hollowing nozzle structure diagram; Figure 4 for Figure 3 Left view of the structural diagram; Figure 5 This is a construction process flow chart of the present utility model.

[0030] In the figure: jet packer 1, packer upper joint 1-0, conversion joint 1-1, flow hole 1-2, anti-loosening screw 1-3, upper leather cup 1-4, lower leather cup 1-5, anti-loosening screw 2 1-6, packer lower joint 1-7, upper center pipe 1-8, leather cup inner tube 1-9; cavitation water jet 2, shell 2-1, cavitation nozzle chamber 2-2; eccentric pulse booster 3, booster upper joint 3-0, anti-loosening screw 3 3-1, eccentric cylinder 3-2, connecting ring 3-3, inner liner 3-4, anti-loosening screw 4 3-5, booster lower joint 3-6, flow hole 2 3-7, flow hole 3 3-8, Adsorption annulus 3-9; cavitation nozzle 4, jet hole 4-1, installation head 4-2, nozzle center hole 4-3, sealing section 4-4; plugging ring 5, lower center pipe 6, high-pressure jet annulus 7; wellhead assembly 8, blowout preventer 8-1, casing valve 8-2; four-way valve 8-3, main valve 8-4, discharge pipeline 9; liquid storage device 10, outlet valve 10-1, liquid storage tank 10-2, sewage valve 10-3; pump truck 11, pump truck outlet pipeline 12, nitrogen truck 13, nitrogen outlet pipeline 14, tee 15, mixed injection pipeline 16, pump truck inlet pipeline 17, oil pipe 18, oil layer 19, casing 20. DETAILED DESCRIPTION

[0031] The accompanying drawings are for reference and illustration purposes only and are not intended to limit the scope of protection of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0033] In the description of the present invention, it should be understood that the terms "length," "width," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," and the like, indicating positions or location relationships, are based on the positions or location relationships shown in the accompanying drawings and are intended solely to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, in the description of the present invention, "plurality" means two or more, unless otherwise expressly and specifically defined.

[0034] See also Figure 1-Figure 5 , a downhole cavitation water jet unblocking device, comprising a jet packer 1 and an eccentric pulse booster 3, wherein: the jet packer 1 is connected with a conversion joint 1-1 between the upper joint 1-0 of the packer and the upper center pipe 1-8 and the leather cup inner pipe 1-9, and the conversion joint 1-1 and the upper center pipe 1-8 are both provided with a flow hole 1-2; the eccentric cylinder 3-2 and the inner liner 3-4 in the eccentric pulse booster 3 are respectively provided with a flow hole 2 3-7 and a flow hole 3-8; the upper center pipe 1-8 is connected to the lower center pipe 6, and a cavitation water jet 2 equipped with a cavitation nozzle 4 is connected to the outside of the lower center pipe 6 between the jet packer 1 and the eccentric pulse booster 3; a blocking ring 5 is provided at the lower end of the annulus between the cavitation water jet 2 and the lower center pipe 6 to form a high-pressure jet annulus 7 connected with the flow hole 1-2.

[0035] In the present invention, a jet packer 1 is connected sequentially from top to bottom to a cavitating water jet 2 and an eccentric pulse booster 3. The two devices are connected via a lower central tube 6, on the outside of which the cavitating water jet 2, equipped with a cavitating nozzle 4, is mounted. A blocking ring 5 is installed at the lower end of the annulus between the cavitating water jet 2 and the lower central tube 6, forming a high-pressure jet annulus 7 that communicates with the flow holes 1-2.

[0036] The high-pressure well-washing fluid mixed with gas can enter the oil layer 19 from the sand control pipe connected to the casing 20 through the cavitation nozzle 4 in the cavitation water jet 2 and impact and vibrate the blockage in the oil layer 19. At the same time, a cavitation low-pressure zone is formed in the annulus between this device and the casing 20. The blockage that is impacted and peeled off is affected by the low-pressure zone in the casing annulus and flows downward with the liquid back to the vicinity of the sand control pipe of the oil well. Under the negative pressure suction action of the eccentric pulse booster 3, the liquid flow mixed with the blockage enters through the lower end of the center hole of the eccentric pulse booster 3, as well as the flow hole 2 3-7 and the flow hole 3 3-8, and returns to the ground from the lower center pipe 6, the upper center pipe 1-8 and the oil pipe 18, completing the impact and unblocking of the oil layer 19.

[0037] Based on the above-mentioned embodiment 1, the present invention also has the following embodiments: A preferred embodiment: more than one cavitation water jet 2 is connected between the jet packer 1 and the eccentric pulse booster 3, and two, three or more cavitation water jets can be connected; the number of connections of the cavitation water jets 2 is determined according to the thickness of the oil layer 19; the cavitation water jets 2 are connected by threads.

[0038] A preferred embodiment: the eccentric pulse supercharger 3 is provided with an eccentric cylinder 3-2, an inner liner 3-4, a supercharger upper joint 3-0 and a supercharger lower joint 3-6, and an eccentric cylinder 3-2 of one level or more is connected to the outside of the inner liner 3-4, and the eccentric cylinders 3-2 are connected by a connecting ring 3-3, and an adsorption annulus 3-9 is formed between the eccentric cylinders 3-2 and the inner liner 3-4 on both sides of the connecting ring 3-3; the supercharger upper joint 3-0 and the supercharger lower joint 3-6 connected to the two ends of the inner liner 3-4 are respectively threadedly connected to the cavitation water jet 2 and the cannula; a tightening screw three 3-1 and a tightening screw two four 3-5 are respectively installed between the supercharger upper joint 3-0 and the supercharger lower joint 3-6 and the inner liner 3-4, and the supercharger lower joint 3-6 can be threadedly connected to the cannula.

[0039] A preferred embodiment: the shell 2-1 of the cavitation water jet 2 is a cylindrical body, and the inner circle of the upper end and the outer circle of the lower end are respectively provided with internal threads and external threads, and the cavitation nozzle 4 is installed in the cavitation nozzle cavity 2-2 provided in the shell 2-1.

[0040] In a preferred embodiment, the cavitation nozzle cavity 2-2 is a multi-step installation cavity that is radially connected to the housing 2-1 and is provided with a threaded connection cavity. The cavitation nozzle cavity 2-2 is evenly distributed and obliquely arranged in the housing 2-1.

[0041] A preferred embodiment: more than two rows of cavitation nozzle chambers 2-2 are arranged in the axial direction of the shell 2-1, and more than three cavitation nozzle chambers 2-2 in each row are arranged in the circumferential direction of the shell 2-1, forming multiple effects of low-frequency hydraulic impact, cavitation suction, rotational shear and vibration loosening of blockages.

[0042] A preferred embodiment: the cavitation nozzle 4 installed in the cavitation nozzle cavity 2-2 is a non-uniform hollow cylinder and is provided with a jet hole 4-1, a mounting head 4-2, a cavitation injection cavity 4-3 and a sealing section 4-4; the jet hole 4-1 is connected to the cavitation injection cavity 4-3, and the maximum outer diameter section in the cavitation nozzle 4 is provided with an external thread and can be threadedly connected to the threaded connection cavity in the cavitation nozzle cavity 2-2.

[0043] A preferred embodiment: the jet hole 4-1 is a tapered hole connected to the cavitation injection chamber 4-3 and is small inside and large outside; the outer wall of the mounting head 4-2 is provided with a wrench square that matches the inner tube wrench; the sealing section 4-4 is provided with a sealing ring groove and a sealing ring is installed in the sealing ring groove.

[0044] A preferred embodiment: both ends of the conversion joint 1-1 are provided with internal threads and are threadedly connected to the upper joint 1-0 of the packer and the leather cup inner tube 1-9 respectively, and there is more than one set screw 1-3 in the threaded connection section with the leather cup inner tube 1-9; the flow hole 1-2 is provided in the non-threaded connection section of the conversion joint 1-1, and the flow holes 1-2 in the conversion joint 1-1 and the upper center pipe 1-8 are both provided with more than two; the conversion joint 1-1 is connected between the upper leather cup 1-4 in the jet packer 1 and the upper joint 1-0 of the packer, so that the flow hole 1-1 is located above the upper leather cup 1-4.

[0045] A preferred embodiment: the internal thread in the upper inner cavity of the upper joint 1-0 of the packer is an oil pipe thread and can be threadedly connected to the oil pipe 18, and the internal thread and external thread at the lower part of the upper joint 1-0 of the packer are threadedly connected to the upper center pipe 1-8 and the conversion joint 1-1 respectively; and one or more set screws 1-6 are also installed in the threaded connection section between the leather cup inner tube 1-9 and the lower joint 1-7 of the packer.

[0046] A lower cup 1-5 is mounted outside the inner cup tube 1-9 of the jet packer 1, below the upper cup 1-4. A lower connector 1-7 is threadedly connected to the upper central pipe 1-8 below the lower cup 1-5. A set screw 1-6 is installed at this threaded connection to prevent loosening. When set, the upper and lower cups 1-4, 1-5 seal the annulus between the device and the casing 20. A deblocking fluid, or well-washing fluid, can enter the high-pressure jet annulus 7 within the device through the flow hole 1-2.

[0047] The device's operating principle and on-site usage are as follows: The device is lowered into casing 20 via a construction string connected by oil pipe 18, with the cavitating water jet 2 positioned in the middle of the oil layer 19. The upper portion of the oil pipe 18 is sequentially connected to the main valve 8-4 and the wellhead assembly 8. The casing valve 8-2 of the wellhead assembly 8 is connected to the pump truck outlet pipeline 12 via a mixed injection line 16 and a tee 15. The pump truck outlet pipeline 12 is connected to the pump truck 11 and the tee 15 at both ends, and then to the nitrogen outlet pipeline 14 and the nitrogen truck 13 via the tee 15. The central outlet of the wellhead assembly 8 is connected to the liquid storage device 10 via the blowout preventer 8-1 and the discharge pipeline 9. The lower portion of the liquid reservoir 10-2 in the liquid storage device 10 is equipped with an outlet valve 10-1 and a sewage valve 10-3. The lower portion of the liquid reservoir 10 is connected to the pump truck 11 via the outlet valve 10-1 and the pump truck inlet pipeline 17.

[0048] The well washing fluid mixed with nitrogen enters the oil-casing annulus formed by the oil pipe 18 and the casing 20 through the mixed fluid injection pipeline 16 and the casing valve 8-2 and enters the device through the flow hole 1-2.

[0049] The dirty liquid carrying the blockage is discharged from the eccentric pulse supercharger 3, the oil pipe 18 and the discharge pipeline 9 to the liquid storage device 10, completing the shock unblocking of the oil layer 19.

[0050] In specific use, the present invention is lowered into the sand control pipe at the oil layer 19 along with the construction string. The cannula connected to the lower end of the eccentric pulse booster 3 is inserted into the external filling tool, and the jet packer 1 is set. A well wash fluid and nitrogen are mixed in a certain proportion and injected into the oil-casing annulus through the casing 20. The mixed fluid enters the high-pressure jet annulus 7 of the present invention through the flow hole 1-2 of the jet packer 1. Under the cavitation and pulse action of the multi-stage cavitating water jet 2, it is ejected through the cavitating nozzle 4 installed in the cavitating water jet 2, sprayed at high speed, and enters the annulus between the sand control pipe and the present invention, impacting and vibrating the oil layer 19 and forming a cavitation low-pressure zone in the annulus between the cavitating water jet 2 and the casing 20. Blockages removed by the impact are affected by the cavitation low-pressure zone and flow downward from the eccentric pulse booster 3 back into the cavitation low-pressure zone formed by the present invention and the casing 20.

[0051] Under the negative pressure suction action of the eccentric pulse booster 3, the mixed liquid enters the inner liner 3-4 through the flow hole 2 3-7 and the flow hole 3 3-8 in the eccentric pulse booster 3, and flows back from the bottom of the inner liner 3-4 into the oil pipe 18. Finally, the blockage is returned to the ground through the oil pipe 18 along with the liquid flow.

[0052] The embodiments described above are merely typical embodiments, but the present invention is not limited to these embodiments, and those skilled in the art can make modifications without departing from the spirit and enlightenment of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the creative spirit and creative concept of the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection is not limited to the above description.

Claims

1. A downhole cavitation water jet unblocking device, comprising a jet packer and an eccentric pulse intensifier, characterized by: The jet packer is connected with a conversion joint between the upper joint of the packer and the upper center tube and the inner tube of the leather cup, and a flow hole 1 is provided in the conversion joint and the upper center tube; the eccentric tube and the inner liner tube in the eccentric pulse booster are respectively provided with flow holes 2 and 3; the upper center tube is connected to the lower center tube, and a cavitation water jet equipped with a cavitation nozzle is connected to the outside of the lower center tube between the jet packer and the eccentric pulse booster; a blocking ring is provided at the lower end of the annulus between the cavitation water jet and the lower center tube to form a high-pressure jet annulus connected to the flow hole.

2. A downhole cavitation water jet unblocking device as claimed in claim 1, characterized in that More than one cavitation water jet is connected between the jet packer and the eccentric pulse booster; the number of the connected cavitation water jets is determined according to the thickness of the oil layer; and the cavitation water jets are connected to each other through threads.

3. The downhole cavitation water jet unblocking device according to claim 2, characterized in that: The eccentric pulse supercharger is provided with an eccentric cylinder, an inner liner, an upper supercharger joint and a lower supercharger joint. An eccentric cylinder of one level or more is connected to the outside of the inner liner. The eccentric cylinders are connected by a connecting ring. An adsorption annulus is formed between the eccentric cylinder and the inner liner on both sides of the connecting ring; the upper supercharger joint and the lower supercharger joint connected to the two ends of the inner liner are respectively connected to the cavitation water jet and the cannula thread; a set screw three and a set screw two or four are respectively installed between the upper supercharger joint and the lower supercharger joint and the inner liner, and the lower supercharger joint can be connected to the cannula thread.

4. A downhole cavitation water jet unblocking device according to claim 1, 2 or 3, characterized in that: The shell of the cavitation water jet is a cylindrical body, and the inner circle of the upper end and the outer circle of the lower end are respectively provided with internal threads and external threads. The cavitation nozzle is installed in a cavitation nozzle cavity provided in the shell.

5. The downhole cavitation water jet unblocking device according to claim 4, characterized in that: The cavitation nozzle cavity is a multi-step installation cavity that is radially connected to the housing and is provided with a threaded connection cavity. The cavitation nozzle cavity is evenly distributed and obliquely arranged in the housing.

6. The downhole cavitation water jet unblocking device according to claim 5, characterized in that: More than two rows of cavitation nozzle cavities are arranged in the axial direction of the shell, and more than three cavitation nozzle cavities are arranged in each row in the circumferential direction of the shell.

7. The downhole cavitation water jet unblocking device according to claim 5, characterized in that: The cavitation nozzle installed in the cavitation nozzle cavity is a non-uniform hollow cylinder and is provided with a jet hole, a mounting head, a cavitation injection cavity and a sealing section; the jet hole is connected to the cavitation injection cavity, and the maximum outer diameter section in the cavitation nozzle is provided with an external thread and can be threadedly connected to the threaded connection cavity in the cavitation nozzle cavity.

8. The downhole cavitation water jet unblocking device according to claim 7, characterized in that: The jet hole is a tapered hole connected to the cavitation injection cavity and is small inside and large outside; the outer wall of the mounting head is provided with a wrench square that matches the inner tube wrench; the sealing section is provided with a sealing ring groove and a sealing ring is installed in the sealing ring groove.

9. The downhole cavitation water jet unblocking device according to claim 1, characterized in that: Both ends of the conversion joint are provided with internal threads and are respectively threadedly connected to the upper joint of the packer and the inner tube of the leather cup. There is also one or more set screws in the threaded connection section with the inner tube of the leather cup; the flow hole is arranged in the non-threaded connection section of the conversion joint, and the flow holes in the conversion joint and the upper center pipe are both arranged in two or more; the conversion joint is connected between the upper leather cup in the jet packer and the upper joint of the packer, so that the flow hole is located above the upper leather cup.

10. The downhole cavitation water jet unblocking device according to claim 9, characterized in that: The internal thread in the upper inner cavity of the upper joint of the packer is an oil pipe thread and can be connected to the oil pipe thread. The internal thread and external thread at the lower part of the upper joint of the packer are respectively threadedly connected to the upper center pipe and the conversion joint; one or more set screws 2 are also installed in the threaded connection section between the leather cup inner tube and the lower joint of the packer.

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