A self-excited pulse cavitation jet unblocking device for oilfield production

Abstract

This utility model discloses a self-excited pulse cavitation jet unblocking device for oilfield production, belonging to the field of oilfield production technology. It includes an upper connector, with an outer cylinder threaded to the bottom sidewall of the upper connector. A lower connector is threaded to the bottom sidewall of the outer cylinder. A self-excited oscillating core that forms a periodic pulse jet is installed inside the cavity of the outer cylinder. The self-excited oscillating core is radially connected to the upper connector, outer cylinder, and lower connector. A self-rotating cavitation jet assembly is rotatably connected to the outer sidewall of the lower connector. This utility model, through the self-excited oscillating core and self-oscillating cavitation nozzle, combines the periodic pulse jet generated by the self-excited oscillating core with the high-energy shock wave from the self-oscillating cavitation nozzle, significantly improving unblocking efficiency through the combination of pulse and cavitation. Furthermore, the rotary connector and impeller, with the impeller automatically rotating under fluid drive, cause the jet tube to circumferentially sweep the well wall, increasing the treatment radius.

Description

Technical Field

[0001] This utility model belongs to the field of oilfield production technology, specifically relating to a self-excited pulse cavitation jet unblocking device for oilfield production. Background Technology

[0002] Most oilfields in my country have entered the secondary and tertiary development stages, and water injection has become a common method. As water injection progresses, the formation's water absorption capacity gradually decreases due to reasons such as: blockage caused by formation particles; scaling and corrosion of the water injection tubing; and blockage by bacteria and their metabolites.

[0003] Currently, there are various physical methods for unclogging oil and water wells, including hydraulic oscillation, voltage-hydraulic pulse, high-pressure jet, ultrasonic waves, and hydraulic pulse. Among these, hydraulic pulse unclogging has become a focus of research both domestically and internationally due to its advantages such as simple and convenient construction and its combination with chemical methods.

[0004] However, existing hydraulic pulse unblocking structures generally suffer from prominent problems such as insignificant pulse oscillation effects and low rock-breaking efficiency, and their unblocking efficiency needs to be improved. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a self-excited pulse cavitation jet unblocking device for oilfield production.

[0006] The technical solution adopted to solve the above-mentioned technical problems is: a self-excited pulse cavitation jet unblocking device for oilfield production, including an upper connector, an outer cylinder threaded to the bottom side wall of the upper connector, a lower connector threaded to the bottom side wall of the outer cylinder, a self-excited oscillating core for forming periodic pulse jets installed in the cavity of the outer cylinder, the self-excited oscillating core being radially connected to the upper connector, the outer cylinder and the lower connector, and a fluid-driven self-rotating cavitation jet assembly being rotatably connected to the outer side wall of the lower connector, the self-excited oscillating core and the self-rotating cavitation jet assembly cooperating to achieve the combination of pulse jets and high-energy shock waves.

[0007] Furthermore, the top of the self-excited oscillating core is provided with a constricted jet inlet, and wedge-shaped blocks are symmetrically arranged along the axis inside the cavity of the self-excited oscillating core. The space between the two wedge-shaped blocks is provided as a self-excited oscillating cavity, and the gap between the two wedge-shaped blocks and the cavity of the self-excited oscillating core is provided as a left and right feedback channel. The left and right feedback channels are located on the left and right sides of the self-excited oscillating cavity and are connected to the self-excited oscillating cavity. The bottom end of the self-excited oscillating core is provided with a jet outlet.

[0008] Furthermore, the wedge block is a right-angled triangle, the right angle of the wedge block is set as an arc chamfer, and the width of the self-excited oscillation cavity gradually increases from top to bottom.

[0009] Through the above technical solution, when the fluid flows into the self-excited oscillating core, the fluid is accelerated at the constricted diameter of the constricted jet inlet to generate a high-speed jet. Through the wall adhesion effect, the fluid attached to the wall continuously impacts the continuous jet at the jet outlet along the left and right feedback channels, causing the jet direction to change periodically, automatically realizing the periodic pulse jet effect, generating high-frequency pressure fluctuations, and applying intermittent high-intensity impacts to pollutants in the near-wellbore area.

[0010] Furthermore, the self-rotating cavitation jet assembly includes a rotary joint rotatably mounted on the side wall of the lower connector. A fixed column is provided at the center of the bottom end of the rotary joint along the axis. An impeller is sleeved and fixed on the side wall of the fixed column. A flow-dividing cavity is opened around the fixed column at the bottom inside of the rotary joint. A plurality of jet tubes are opened along the circumference at the bottom end of the rotary joint. All jet tubes are in communication with the flow-dividing cavity. A self-vibrating cavitation nozzle is fixedly connected to the bottom end of the jet tube.

[0011] Through the above technical solution, when high-pressure water enters the lower connector, the water flow exerts a force on the impeller, causing it to rotate. The impeller then drives the rotary joint to rotate automatically, thereby achieving the revolution of each self-oscillating cavitation nozzle. Simultaneously, the high-pressure water flow is diverted through the flow distribution chamber within the rotary joint to each jet pipe, and then ejected through the self-oscillating cavitation nozzle. The high-speed fluid induces cavitation bubble collapse, releasing instantaneous high-temperature, high-pressure micro-jet and ultrasonic waves, further breaking down dense blockages such as scale and asphalt deposits. The automatically revolving self-oscillating cavitation nozzle achieves 360° coverage without dead angles, making it suitable for complex well conditions such as horizontal wells and highly deviated wells.

[0012] Furthermore, both the fixed column and the impeller are located inside the lower connector, the impeller and the lower connector do not contact each other, and the bottom end of the rotary connector is provided with a pipe connector.

[0013] The above technical solution reduces frictional losses while allowing for dynamic adjustment of rotational speed based on actual flow velocity, thus optimizing energy distribution. The pipe fitting provides a connection to high-pressure pipelines.

[0014] Furthermore, the outer side wall of the lower connector has two storage grooves, and the inner side wall of the rotary connector has a storage groove corresponding to the position of the storage grooves. The inner side walls of the two storage grooves are respectively fitted with guide rings and sealing rings, with the sealing rings located below the guide rings.

[0015] Through the above technical solution, the first and second storage tanks are nested together, and with the help of guide rings and sealing rings, the high-pressure environment downhole is effectively isolated to prevent sand particles from intruding and damaging the internal structure.

[0016] The beneficial effects of this utility model are as follows:

[0017] (1) By setting up a self-excited oscillating core and a self-excited cavitation nozzle, the periodic pulse jet generated by the self-excited oscillating core applies intermittent high-intensity impact to the pollutants in the near-wellbore area. Combined with the high-energy shock wave of the self-excited cavitation nozzle, it induces cavitation collapse in the high-speed fluid, releases instantaneous high-temperature and high-pressure micro-jet and ultrasonic waves, further disintegrates the dense blockage, and forms a "pulse + cavitation" composite action mechanism, which significantly improves the unblocking efficiency.

[0018] (2) Through the set rotary joint and impeller, the impeller is driven by the fluid to rotate automatically, which drives the jet pipe to sweep the well wall in a circumferential direction, thereby increasing the treatment radius. No external power source is required, and it is completely driven by hydraulic power, thus reducing the failure rate. Attached Figure Description

[0019] Figure 1 This is a perspective view of a self-excited pulse cavitation jet unblocking device for oilfield production according to this utility model;

[0020] Figure 2 This is a cross-sectional view of a self-excited pulse cavitation jet unblocking device for oilfield production according to this utility model;

[0021] Figure 3 This is a structural diagram of the self-rotating cavitation jet component of a self-excited pulse cavitation jet unblocking device for oilfield production according to this utility model;

[0022] Figure 4 yes Figure 2 Enlarged view of point A;

[0023] Figure 5 This is a flowchart of the working process of a self-excited pulse cavitation jet unblocking device for oilfield production according to this utility model.

[0024] Reference numerals: 1. Upper connector; 2. Outer cylinder; 3. Pipe connector; 4. Lower connector; 5. Self-excited oscillating core; 6. Self-rotating cavitation jet assembly; 7. Guide ring; 8. Sealing ring; 401. Receiving groove one; 501. Narrowed jet inlet; 502. Self-excited oscillating cavity; 503. Left and right feedback channels; 504. Jet outlet; 505. Wedge block; 601. Rotary joint; 6011. Receiving groove two; 602. Flow divider cavity; 603. Fixed column; 604. Impeller; 605. Jet pipe; 606. Self-vibrating cavitation nozzle. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0026] like Figures 1-4As shown in this embodiment, a self-excited pulse cavitation jet unblocking device for oilfield production includes an upper connector 1. An outer cylinder 2 is threadedly connected to the bottom side wall of the upper connector 1, and a lower connector 4 is threadedly connected to the bottom side wall of the outer cylinder 2. A self-excited oscillating core 5 that forms a periodic pulse jet is installed inside the cavity of the outer cylinder 2. The self-excited oscillating core 5 is radially connected to the upper connector 1, the outer cylinder 2, and the lower connector 4. A fluid-driven self-rotating cavitation jet assembly 6 is rotatably connected to the outer side wall of the lower connector 4. The self-excited oscillating core 5 and the self-rotating cavitation jet assembly 6 work together to combine the pulse jet with the high-energy shock wave. The periodic pulse jet generated by the self-excited oscillating core 5, combined with the high-energy shock wave of the self-rotating cavitation jet assembly 6, forms a "pulse + cavitation" composite action mechanism, which significantly improves the unblocking efficiency. Multiple rounds of pulse-cavitation combined treatment can be completed in a single operation, reducing the number of repeated construction operations.

[0027] The top of the self-excited oscillating core 5 is provided with a constricted jet inlet 501. The cavity of the self-excited oscillating core 5 is symmetrically provided with wedge blocks 505 along the axis. The space between the two wedge blocks 505 is provided as a self-excited oscillating cavity 502. The gap between the two wedge blocks 505 and the cavity of the self-excited oscillating core 5 is provided as a left and right feedback channel 503. The left and right feedback channels 503 are located on the left and right sides of the self-excited oscillating cavity 502 and are connected to the self-excited oscillating cavity 502. The bottom end of the self-excited oscillating core 5 is provided with a jet outlet 504. The wedge blocks 505 are right-angled triangles and the right angles of the wedge blocks 505 are provided as arc chamfers. The width of the self-excited oscillating cavity 502 gradually increases from top to bottom.

[0028] As fluid flows into the self-excited oscillating core 5, it is accelerated at the constricted jet inlet 501, generating a high-speed jet. Through the wall adhesion effect, the jet continuously adheres to the left and right sidewalls of the self-excited oscillating cavity 502. Constrained by the flow channels, the fluid adhering to the walls enters the lower corner reversing circle region along the left and right feedback channels 503, turning the water flow. The turned water flows upward within the left and right feedback channels 503 and then flows back into the self-excited oscillating cavity 502. Because the high-speed fluid continuously and alternately impacts the continuous jet at the jet outlet 504 through the left and right feedback channels, the jet direction changes periodically, causing periodic changes in the vortex flow field inside the self-excited oscillating cavity 502, automatically achieving a periodic pulse jet effect. Utilizing fluid dynamics principles (such as the wall adhesion effect and feedback channels), high-frequency pressure fluctuations are generated, applying intermittent high-intensity impacts to contaminants in the near-wellbore zone.

[0029] The self-rotating cavitation jet assembly 6 includes a rotary joint 601 rotatably mounted on the side wall of the lower joint 4. A fixed column 603 is provided at the center of the bottom end of the rotary joint 601 along the axis. An impeller 604 is sleeved and fixed on the side wall of the fixed column 603. Both the fixed column 603 and the impeller 604 are located inside the lower joint 4. The impeller 604 does not contact the lower joint 4, which reduces friction loss and allows the rotation speed to be dynamically adjusted according to the actual flow rate, thus optimizing energy distribution. A pipe joint 3 is provided at the bottom end of the rotary joint 601 to provide conditions for connection with high-pressure pipelines. A flow-dividing cavity 602 is opened around the fixed column 603 at the bottom end of the rotary joint 601. Several jet pipes 605 are opened along the circumference at the bottom end of the rotary joint 601. All jet pipes 605 are connected to the flow-dividing cavity 602. A self-vibrating cavitation nozzle 606 is fixedly connected to the bottom end of the jet pipe 605.

[0030] When the high-pressure water flow enters the lower connector 4, the water flow exerts a force on the impeller 604, causing it to rotate. Since the impeller 604 is fixedly connected to the rotary connector 601, the impeller 604 drives the rotary connector 601 to rotate automatically, thereby enabling each self-oscillating cavitation nozzle 606 to revolve. Simultaneously, the high-pressure water flow is diverted through the diversion chamber 602 within the rotary connector 601 to each jet pipe 605, and then ejected through the self-oscillating cavitation nozzle 606. The high-speed fluid induces cavitation bubble collapse, releasing instantaneous high-temperature and high-pressure micro-jet and ultrasonic waves, further breaking down dense blockages (such as scale and asphalt deposits). The automatically revolving self-oscillating cavitation nozzle 606 achieves 360° coverage without dead angles, suitable for complex well conditions such as horizontal wells and highly deviated wells, avoiding untreated areas caused by tool eccentricity. Furthermore, the self-rotating assembly does not require an external power source, relying entirely on hydraulic power for drive, reducing the failure rate. The periodic pulse jet generated by the self-excited oscillating core 5, combined with the high-energy shock wave of the self-rotating cavitation jet component 6, forms a "pulse + cavitation" composite action mechanism. Through physical field coupling (pressure wave + cavitation impact + acoustic resonance), the unblocking efficiency is significantly improved.

[0031] The outer side wall of the lower connector 4 has two storage grooves 401, and the inner side wall of the rotary connector 601 has a storage groove 6011 corresponding to the position of the storage groove 401. The inner side walls of the two storage grooves 401 are respectively fitted with a guide ring 7 and a sealing ring 8. The sealing ring 8 is located below the guide ring 7. The storage grooves 401 and 6011 are nested together, and together with the guide ring 7 and the sealing ring 8, they effectively isolate the high-pressure environment downhole and prevent sand particles from entering and damaging the internal structure.

[0032] like Figure 5As shown, in field applications, a bypass process is added next to the main unit, and the unit is connected to the bypass process through a high-pressure tee. The two valves at the high-pressure tee at the process inlet control the process switching, and the high-pressure tee at the process outlet ensures the process continuity, so that the main unit can be used intermittently and the service life of the unit is improved.

[0033] The working principle of this embodiment is as follows: When in use, connect the pump pipeline to the high-pressure tee at the process inlet, connect the pipe joint 3 and the upper joint 1 to the two high-pressure tees respectively, close the valve of the bypass process, start the pump pipeline, and the high-pressure fluid enters the self-excited oscillating core 5 through the upper joint 1. Through the cooperation of the self-excited oscillating cavity 502, the left and right feedback channels 503 and the jet outlet 504, an intermittent pulse jet is formed.

[0034] When the pulsed jet enters the lower connector 4, the water flow exerts a force on the impeller 604, causing it to rotate. The impeller 604 then drives the rotary connector 601 to rotate automatically, thereby enabling each self-oscillating cavitation nozzle 606 to revolve. The pulsed water flow is diverted through the diversion chamber 602 within the rotary connector 601 to each jet pipe 605, and then ejected through the self-oscillating cavitation nozzle 606. The high-speed fluid induces cavitation collapse, releasing instantaneous high-temperature and high-pressure micro-jet and ultrasonic waves. This, combined with the self-excited oscillating core 5, forms a "pulse + cavitation" composite action mechanism, significantly improving the unblocking efficiency. The automatically revolving self-oscillating cavitation nozzle 606 achieves coverage without dead angles, further enhancing the unblocking efficiency.

[0035] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the scope of protection of the present utility model.

Claims

1. A self-excited pulse cavitation jet unblocking device for oilfield production, comprising an upper connector (1), characterized in that: The bottom side wall of the upper connector (1) is threadedly connected to the outer cylinder (2), and the bottom side wall of the outer cylinder (2) is threadedly connected to the lower connector (4). A self-excited oscillating core (5) that forms a periodic pulse jet is installed in the cavity of the outer cylinder (2). The self-excited oscillating core (5) is radially connected to the upper connector (1), the outer cylinder (2), and the lower connector (4). The outer side wall of the lower connector (4) is rotatably connected to a fluid-driven self-rotating cavitation jet assembly (6). The self-excited oscillating core (5) and the self-rotating cavitation jet assembly (6) work together to achieve the combination of pulse jet and high-energy shock wave.

2. The self-excited pulsating cavitating jet plug removal device for oilfield production of claim 1, wherein, The top of the self-excited oscillating core (5) is provided with a constricted jet inlet (501). The cavity of the self-excited oscillating core (5) is symmetrically provided with wedge blocks (505) along the axis. The space between the two wedge blocks (505) is provided as a self-excited oscillating cavity (502). The gap between the two wedge blocks (505) and the cavity of the self-excited oscillating core (5) is provided as a left and right feedback channel (503). The left and right feedback channels (503) are located on the left and right sides of the self-excited oscillating cavity (502) and are connected to the self-excited oscillating cavity (502). The bottom end of the self-excited oscillating core (5) is provided with a jet outlet (504).

3. The self-excited pulsating cavitating jet plug removal device for oilfield production of claim 2, wherein, The wedge block (505) is a right triangle, and the right angle of the wedge block (505) is set as an arc chamfer. The width of the self-excited oscillation cavity (502) gradually increases from top to bottom.

4. The self-excited pulsating cavitating jet plug removal device for oilfield production of claim 1, wherein, The self-rotating cavitation jet assembly (6) includes a rotary joint (601) rotatably mounted on the side wall of the lower joint (4). A fixed column (603) is provided at the center of the bottom end of the rotary joint (601) along the axis. An impeller (604) is sleeved and fixed on the side wall of the fixed column (603). A flow-dividing cavity (602) is opened around the fixed column (603) at the bottom end of the rotary joint (601). A plurality of jet tubes (605) are opened along the circumference at the bottom end of the rotary joint (601). All jet tubes (605) are connected to the flow-dividing cavity (602). A self-vibrating cavitation nozzle (606) is fixedly connected to the bottom end of the jet tube (605).

5. The self-excited pulsating cavitating jet plug removal device for oilfield production of claim 4, wherein, The fixed column (603) and the impeller (604) are both located inside the lower connector (4). The impeller (604) and the lower connector (4) do not contact each other. The bottom end of the rotary connector (601) is provided with a pipe connector (3).

6. A self-excited pulsating cavitating jet unblocking device for oilfield production according to claim 4, characterized in that, The outer side wall of the lower connector (4) has two storage grooves (401), and the inner side wall of the rotary connector (601) has a storage groove (6011) corresponding to the position of the storage groove (401). The inner side walls of the two storage grooves (401) are respectively fitted with a guide ring (7) and a sealing ring (8), and the sealing ring (8) is located below the guide ring (7).

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