A reverse circulation energy-saving device and method for oil well paraffin removal

Abstract

The application belongs to the technical field of oil production engineering, and provides a reverse circulation energy-saving device and method for oil well wax removal, wherein the reverse circulation energy-saving device for oil well wax removal comprises a central pipe, a main body protection pipe, a liquid passing switch, a reset spring, a connecting pipe, an upper joint, a lower joint, vulcanized sealing rubber pads, a one-way sealing rubber sleeve and a sleeve pipe; a plurality of liquid passing openings are formed in the central pipe, the top end of the central pipe is detachably and sealingly connected with the connecting pipe, the top end of the connecting pipe is detachably and sealingly connected with the upper joint, the top end of the upper joint is detachably and sealingly connected with the oil well pipe, the bottom end of the central pipe is detachably and sealingly connected with the lower joint, and the lower joint is detachably and sealingly connected with the main body protection pipe; the application realizes the directional water guiding and sealing blocking of hot water through the cooperation of various components, solves the problems of hot water heat loss, resource waste and high operation cost in the prior art, has strong structure adaptability, and is suitable for various oil well hot washing and wax removal operations.

Description

Technical Field

[0001] This invention belongs to the field of oil production engineering technology, and particularly relates to a reverse circulation energy-saving device and method for oil well dewaxing. Background Technology

[0002] In the field of oil production engineering, some blocks have crude oil with high wax content. During extraction, the wax easily adheres to the inner wall of the tubing, forming a wax deposit that narrows the tubing passage and affects the oil recovery rate. To solve this problem, existing technologies typically employ hot washing to remove the wax. The specific method involves pressurizing hot water using a pump truck, connecting the wellhead valve group to inject hot water into the casing, and using the suction generated by the pumping unit to draw the hot water into the well tubing. The hot water repeatedly washes away the wax deposits, thus achieving the desired wax removal effect.

[0003] However, existing hot washing and wax removal technologies have the following three prominent problems:

[0004] In the existing technology, hot water needs to flow a long distance after being injected from the wellhead to reach the wax-deposited area of ​​the oil well. During this process, the hot water exchanges heat with the casing wall and the surrounding environment, resulting in a significant drop in the temperature of the hot water. When it reaches the wax-deposited point, the heat value is insufficient, which cannot fully dissolve and wash away the wax, thus affecting the wax removal effect.

[0005] During the process of transporting hot water to the bottom of the oil well, it needs to pass through rock formations and oil layers. Due to the lack of an effective sealing and guiding structure, some of the pressurized hot water will seep into the rock formations and oil layers, resulting in a large waste of hot water resources and increasing the total amount of hot water required for the operation.

[0006] Waste of hot water resources leads to a reduction in the amount of hot water effectively used for dewaxing. In order to achieve the expected dewaxing effect, the operation time needs to be extended, which in turn increases the operating cost of crude oil recovery and reduces the overall operating efficiency.

[0007] Therefore, a reverse circulation energy-saving device and method for oil well dewaxing is needed to solve the above problems. Summary of the Invention

[0008] The purpose of this invention is to provide a reverse circulation energy-saving device and method for oil well dewaxing, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a reverse circulation energy-saving device for oil well dewaxing, comprising a central pipe, a main protective pipe, a fluid transfer switch, a reset spring, connecting components, and sealing components;

[0010] The central tube has several fluid passage ports inside. Both ends of the central tube are detachably and sealed to the oil well pipe and the main protective pipe through the connecting components. A pressure-filled fluid passage hole is provided between the central tube and the connecting component near the oil well pipe.

[0011] The main protective tube is sleeved outside the central tube, and an installation gap is formed between the main protective tube and the central tube. The reset spring is located in the installation gap. One end of the reset spring is connected to the end of the main protective tube near the bottom of the central tube, and the other end of the reset spring is connected to the liquid flow switch.

[0012] The liquid transfer switch is slidably assembled inside the main protective tube, the liquid transfer switch is correspondingly arranged with the central tube, and the sealing component is located between the liquid transfer switch and the central tube;

[0013] A one-way sealing component is also provided between the main protective tube and the central tube. A sleeve is fitted outside the main protective tube, and a gap is formed between the sleeve and the main protective tube.

[0014] In a further technical solution, the connecting component includes a connecting pipe, an upper connector, and a lower connector;

[0015] The connecting pipe is located between the top of the central pipe and the upper connector. The top of the central pipe is detachably and sealed to the connecting pipe. The top of the connecting pipe is detachably and sealed to the upper connector. The top of the upper connector is detachably and sealed to the oil well pipe.

[0016] The lower connector is located between the bottom end of the central tube and the main protective tube. The bottom end of the central tube and the lower connector are detachably and sealed together. The lower connector and the main protective tube are detachably and sealed together.

[0017] The pressure-filled liquid passage is opened through the mating part of the central tube and the connecting tube, and the pressure-filled liquid passage is connected to the liquid passage port inside the central tube.

[0018] In a further technical solution, the central pipe and the connecting pipe, the connecting pipe and the upper connector, the upper connector and the oil well pipe, the central pipe and the lower connector, and the lower connector and the main protective pipe are all connected by threaded sealing, and the axes of each connection part coincide.

[0019] In a further technical solution, the sealing component is a vulcanized sealing rubber gasket, which is embedded on the outer periphery of the liquid flow switch and is in close contact with the inner wall of the central tube.

[0020] In a further technical solution, the one-way sealing component is a one-way sealing sleeve, which is fitted between the central tube and the main protective tube, and the bottom end of the one-way sealing sleeve is sealed and connected inside the main protective tube.

[0021] In a further technical solution, the liquid-passing switch has a columnar structure, the liquid-passing switch slides in conjunction with the inner wall of the main protective tube, the liquid-passing switch can slide along the axial direction of the central tube, and the sliding stroke of the liquid-passing switch corresponds to the position of the liquid-passing port.

[0022] In a further technical solution, the liquid passage ports are evenly distributed along the circumference and axial direction of the central tube, and the number of liquid passage ports is at least one.

[0023] The sleeve pressure liquid passage hole and the liquid passage port are connected in a one-to-one correspondence, and the diameter of the sleeve pressure liquid passage hole is not greater than the diameter of the liquid passage port.

[0024] In a further technical solution, one end of the reset spring abuts against the top of the lower connector, and the other end of the reset spring abuts against the bottom of the liquid-passing switch.

[0025] In a further technical solution, the inner diameter of the main protective tube is larger than the outer diameter of the central tube, the main protective tube and the central tube are coaxially arranged, and the installation gap formed by the main protective tube and the central tube is used to accommodate the return spring and the one-way sealing sleeve.

[0026] A reverse circulation energy-saving method for oil well dewaxing, applied to any of the above-described reverse circulation energy-saving devices for oil well dewaxing, includes the following steps:

[0027] S1. Assembly Device: Assemble the sealing component onto the liquid transfer switch, and assemble the return spring and liquid transfer switch sequentially into the installation gap between the main casing and the central casing, so that one end of the return spring abuts against the lower connector and the other end of the return spring abuts against the liquid transfer switch; seal the central casing with the well casing and the main casing through the connecting component, assemble the one-way sealing component between the central casing and the main casing to complete the overall assembly of the device, and place the device in the annular space between the casing and the well casing to ensure that the device is below the wax deposition point;

[0028] S2. Connecting Pipeline: Seal and connect the pump truck's water outlet pipeline to the wellhead casing valve assembly;

[0029] S3. Hot water pressurized injection: Start the pump truck and pressurize the hot water into the casing. The hot water flows along the gap between the casing and the main protective pipe and accumulates on one side of the one-way sealing component.

[0030] S4. Sealing and blocking: When the water pressure inside the sleeve reaches the set value, the one-way sealing component is sealed by the water pressure.

[0031] S5. Opening of the flow channel: The continuously injected hot water enters the mating part of the central pipe and the connecting pipe through the pressure-filled liquid hole, and then acts on the liquid-filled switch after being guided by the liquid port. The thrust generated by the water pressure overcomes the elastic force of the reset spring and pushes the liquid-filled switch to slide along the central pipe axis, and the liquid-filled port is fully opened.

[0032] S6. Wax Removal Operation: Hot water enters the central pipe through the liquid inlet, and then enters the oil well pipe through the connection part of the connecting component. The pumping unit works normally and pumps the hot water and crude oil mixture in the oil well pipe upward together. The mixture passes through the wax point.

[0033] S7. Operation Reset: When the temperature of the wellhead outlet pipeline and the injected hot water temperature tend to be consistent, maintain for a set time, and then shut down the pump truck and casing valve group; the water pressure in the casing drops, the one-way sealing component resets, and the gap is restored to unobstructed flow; at the same time, the reset spring elastically extends, and the reset spring pushes the liquid flow switch to reset, the sealing component fits and seals with the liquid flow port, and the device returns to its initial state.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] This invention, through the connecting component, installs the entire device below the wax deposition point, significantly shortening the transportation distance of hot water from the injection point to the wax deposition point; at the same time, the sleeve pressure through hole between the central tube and the connecting tube is precisely connected to the through port inside the central tube, allowing hot water to quickly and directly enter the interior of the central tube, and then enter the oil well pipe through the connecting component and pass through the wax deposition point, reducing heat exchange during the transportation process of hot water, maximizing the retention of the hot water's heat value, ensuring that the hot water can fully dissolve and flush away the wax, and significantly improving the wax removal effect;

[0036] This invention, by setting a one-way sealing sleeve between the central tube and the main casing, allows the one-way sealing sleeve to adhere to the inner wall of the main casing under water pressure, forming a reliable seal and blocking the leakage path of hot water to the rock and oil layers below and around the casing. At the same time, the vulcanized sealing rubber gasket on the fluid transfer switch achieves a sliding seal between the fluid transfer switch and the central tube, preventing hot water from leaking from the mating gap and ensuring that all hot water can enter the well casing along the preset path to participate in the dewaxing operation, effectively reducing the waste of hot water resources and reducing the total amount of hot water required for the operation.

[0037] This invention reduces the waste of hot water resources, ensuring an effective amount of hot water for wax removal without compensating for insufficient hot water by extending the operation time, thus significantly shortening the wax removal cycle. The shortened operation cycle not only reduces direct operating costs such as pump truck energy consumption and manual operation, but also reduces indirect losses caused by oil well shutdowns due to wax removal. At the same time, the device has a simple structure, is easy to assemble, and has low maintenance costs, further reducing the overall operating cost of crude oil recovery and improving operational efficiency and economic efficiency.

[0038] To more clearly illustrate the structural features and effects of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0039] Figure 1 This is a structural schematic diagram of the overall cross-section of the present invention;

[0040] Figure 2 This is a schematic diagram of a partial cross-section of the present invention;

[0041] Figure 3 This is a schematic diagram of the cross-sectional structure of the connector of the present invention;

[0042] Figure 4 This is a schematic diagram of the cross-section of the connecting pipe of the present invention;

[0043] Figure 5 This is a structural schematic diagram of the cross-section of the central tube of the present invention.

[0044] In the diagram: 1. Central tube; 101. Fluid inlet; 2. Connecting tube; 3. Upper connector; 4. Lower connector; 5. Main casing; 6. Fluid inlet switch; 601. Vulcanized sealing rubber gasket; 7. Return spring; 8. Sleeve pressure fluid inlet; 9. One-way sealing sleeve; 10. Casing; 11. Oil well tubing. Detailed Implementation

[0045] The present invention will be further described below with reference to embodiments.

[0046] The following embodiments are used to illustrate the present invention, but should not be used to limit the scope of protection of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions, and simple improvements to the method of the present invention under the premise of the concept of the present invention are all within the scope of protection claimed by the present invention.

[0047] Please see Figure 1-5 The present invention provides a reverse circulation energy-saving device for oil well dewaxing, comprising a central pipe 1, a main protective pipe 5, a liquid flow switch 6, a return spring 7, connecting components and sealing components;

[0048] The center tube 1 has several fluid passage ports 101 inside. The two ends of the center tube 1 are detachably and sealed to the oil well pipe 11 and the main protective pipe 5 through connecting components. A sleeve pressure fluid passage hole 8 is provided between the center tube 1 and the connecting component near the oil well pipe 11.

[0049] The main protective tube 5 is sleeved outside the central tube 1, and an installation gap is formed between the main protective tube 5 and the central tube 1. The reset spring 7 is located in the installation gap. One end of the reset spring 7 is connected to the end of the main protective tube 5 near the bottom of the central tube 1, and the other end of the reset spring 7 is connected to the liquid flow switch 6.

[0050] The liquid transfer switch 6 is slidably assembled inside the main protective tube 5. The liquid transfer switch 6 is correspondingly set with the central tube 1, and the sealing component is located between the liquid transfer switch 6 and the central tube 1.

[0051] A one-way sealing component is also provided between the main protective tube 5 and the central tube 1. A sleeve 10 is sleeved on the outside of the main protective tube 5, and a gap is formed between the sleeve 10 and the main protective tube 5.

[0052] In this embodiment, by setting core components such as the central pipe 1, the main protective pipe 5, and the liquid transfer switch 6, the assembly logic of each component is clarified, ensuring that each component can cooperate in a coordinated manner, providing a basis for further definition of each dependent claim, and realizing the basic assembly function of the device, ensuring that the device can be stably installed in the oil well, and providing structural support for the smooth implementation of subsequent wax removal operations.

[0053] The core structural system of the device was constructed, and the assembly standards of each component were clarified to ensure the integrity of the device structure, the stability of the assembly, and its adaptability to the installation requirements of the oil well site.

[0054] Specifically, the connecting components include a connecting pipe 2, an upper connector 3, and a lower connector 4;

[0055] The connecting pipe 2 is located between the top of the central pipe 1 and the upper connector 3. The top of the central pipe 1 is detachably and sealed to the connecting pipe 2. The top of the connecting pipe 2 is detachably and sealed to the upper connector 3. The top of the upper connector 3 is detachably and sealed to the oil well pipe 11.

[0056] The lower connector 4 is located between the bottom end of the central tube 1 and the main protective tube 5. The bottom end of the central tube 1 and the lower connector 4 are detachably and sealedly connected, and the lower connector 4 and the main protective tube 5 are detachably and sealedly connected.

[0057] The pressure-through hole 8 is opened through the mating part of the central tube 1 and the connecting tube 2, and the pressure-through hole 8 is connected to the liquid outlet 101 inside the central tube 1.

[0058] In this embodiment, the specific locations of the connecting pipe 2, the upper connector 3, and the lower connector 4, as well as their connection methods with the central pipe 1, the main protective pipe 5, and the oil well pipe 11, are clearly defined. At the same time, the location of the casing pressure fluid passage hole 8 and its communication relationship with the fluid passage port 101 are also clearly defined.

[0059] The connection structure of the device has been refined, making the connection relationship of each component clearer and ensuring that the connection between the central pipe 1 and the oil well pipe 11 and the main protective pipe 5 is stable and reliable. At the same time, it realizes the precise connection between the casing pressure liquid passage hole 8 and the liquid passage port 101, providing structural guarantee for the smooth flow of hot water and avoiding assembly difficulties or problems with poor hot water flow caused by unclear connections.

[0060] Specifically, the central pipe 1 and the connecting pipe 2, the connecting pipe 2 and the upper connector 3, the upper connector 3 and the oil well pipe 11, the central pipe 1 and the lower connector 4, and the lower connector 4 and the main protective pipe 5 are all connected by threaded seals, and the axes of each connection part coincide.

[0061] In this embodiment, the sealing and coaxiality of the connections between the components are further enhanced. The threaded sealing connection method facilitates the disassembly, assembly and maintenance of the device, while ensuring that the components are set coaxially, avoiding problems such as slippage and jamming of the liquid switch 6 and poor sealing caused by assembly misalignment, thereby improving the assembly accuracy and working stability of the device and extending the service life of the device.

[0062] Specifically, the sealing component is a vulcanized sealing rubber gasket 601, which is embedded on the outer periphery of the liquid flow switch 6 and is in close contact with the inner wall of the central tube 1.

[0063] In this embodiment, a sliding seal is achieved between the liquid flow switch 6 and the central tube 1 to ensure the sealing of the mating parts and prevent hot water from leaking from the mating gap. At the same time, it provides a guarantee for the on / off sealing of the liquid flow port 101, ensuring that the liquid flow switch 6 can accurately block and open the liquid flow port 101, thereby improving the sealing reliability of the device.

[0064] Specifically, the one-way sealing component is a one-way sealing sleeve 9, which is fitted between the central tube 1 and the main protective tube 5, and the bottom end of the one-way sealing sleeve 9 is sealed and connected inside the main protective tube 5.

[0065] In this embodiment, a reliable sealing structure can be formed under water pressure to block the leakage path of hot water, ensuring that hot water can be guided along a preset path, providing a sealing guarantee for the efficient use of hot water, and avoiding the waste of hot water due to seal failure.

[0066] Specifically, the liquid transfer switch 6 has a columnar structure and slides against the inner wall of the main protective tube 5. The liquid transfer switch 6 can slide along the axial direction of the central tube 1, and the sliding stroke of the liquid transfer switch 6 corresponds to the position of the liquid transfer port 101.

[0067] In this embodiment, it is ensured that the liquid flow switch 6 can slide smoothly along the central tube 1 axis to avoid sliding jamming. At the same time, it is ensured that the liquid flow switch 6 can accurately achieve the complete opening or blocking of the liquid flow port 101 after sliding, so as to ensure that the hot water flow channel is controllable and improve the working reliability and stability of the device.

[0068] Specifically, the liquid passage 101 is evenly distributed along the circumference and axial direction of the central tube 1, and the number of liquid passage 101 is at least one.

[0069] The pressure-through hole 8 and the liquid passage 101 are connected in a one-to-one correspondence, and the diameter of the pressure-through hole 8 is not greater than the diameter of the liquid passage 101.

[0070] In this embodiment, hot water is ensured to enter the central pipe 1 evenly and smoothly, avoiding poor flow due to uneven distribution of the liquid outlets 101. At the same time, by reasonably setting the aperture relationship, the resistance during the hot water flow process is reduced, the flow efficiency of hot water is improved, and a sufficient amount of hot water can enter the oil well pipe 11 to participate in the wax removal operation.

[0071] Specifically, one end of the return spring 7 abuts against the top of the lower connector 4, and the other end of the return spring 7 abuts against the bottom of the liquid-passing switch 6.

[0072] In this embodiment, the reset spring 7 is stably installed in the installation gap between the main protective tube 5 and the central tube 1, providing a stable elastic reset force for the liquid flow switch 6. This ensures that the liquid flow switch 6 can accurately reset and seal the liquid flow port 101 after the operation is completed, ensuring that the device can be used repeatedly and improving the practicality and ease of operation of the device.

[0073] Specifically, the inner diameter of the main protective tube 5 is larger than the outer diameter of the central tube 1. The main protective tube 5 and the central tube 1 are coaxially arranged. The installation gap formed by the main protective tube 5 and the central tube 1 is used to accommodate the return spring 7 and the one-way sealing sleeve 9.

[0074] In this embodiment, it is ensured that the main protective tube 5 and the central tube 1 can be stably assembled, and the resulting installation gap can reasonably accommodate components such as the return spring 7 and the one-way sealing sleeve 9, avoiding work interference caused by component crowding. At the same time, it ensures that each component can work normally within the gap, thus guaranteeing the overall assembly rationality and working stability of the device.

[0075] A reverse circulation energy-saving method for oil well dewaxing, applied to the reverse circulation energy-saving device for oil well dewaxing described in the above embodiments, includes the following steps:

[0076] S1. Assembly device: Assemble the sealing component onto the liquid transfer switch 6. Assemble the return spring 7 and the liquid transfer switch 6 sequentially into the installation gap between the main casing 5 and the central pipe 1, so that one end of the return spring 7 abuts against the lower connector 4 and the other end of the return spring 7 abuts against the liquid transfer switch 6. Seal the connection between the central pipe 1, the well pipe 11, and the main casing 5 through the connecting component. Assemble the one-way sealing component between the central pipe 1 and the main casing 5 to complete the overall assembly of the device. Place the device in the annular space between the casing 10 and the well pipe 11 to ensure that the device is below the wax deposition point.

[0077] S2. Connecting Pipeline: Seal and connect the pump truck's water outlet pipeline to the wellhead casing valve group 10.

[0078] S3, Hot water pressurized injection: Start the pump truck and pressurize the hot water into the casing 10. The hot water flows along the gap between the casing 10 and the main protective pipe 5 and accumulates on one side of the one-way sealing component.

[0079] S4. Sealing and blocking: When the water pressure inside the sleeve 10 reaches the set value, the one-way sealing component is sealed by the water pressure.

[0080] S5. Opening of the flow channel: The continuously injected hot water enters the mating part of the central tube 1 and the connecting tube 2 through the pressure-filled liquid hole 8, and then acts on the liquid-filled switch 6 after being guided by the liquid port 101. The thrust generated by the water pressure overcomes the elastic force of the reset spring 7 and pushes the liquid-filled switch 6 to slide along the axial direction of the central tube 1, and the liquid-filled port 101 is fully opened.

[0081] S6. Wax Removal Operation: Hot water enters the interior of the central pipe 1 through the liquid inlet 101, and then enters the oil well pipe 11 through the connection part of the connecting component. The pumping unit works normally and pumps the hot water and crude oil mixture in the oil well pipe 11 upward together. The mixture passes through the wax point.

[0082] S7. Operation Reset: When the temperature of the wellhead outlet pipeline and the injected hot water temperature tend to be consistent, maintain the set time, and then shut down the pump truck and the casing 10 valve group; the water pressure in the casing 10 drops, the one-way sealing component resets, and the gap is restored to unobstructed; at the same time, the reset spring 7 elastically extends, the reset spring 7 pushes the liquid flow switch 6 to reset, the sealing component fits and seals with the liquid flow port 101, and the device returns to the initial state.

[0083] Working principle and usage process of this invention:

[0084] Assembly Stage: First, the entire device is assembled. The vulcanized sealing rubber gasket 601 is embedded in the annular groove on the outer periphery of the liquid flow switch 6, ensuring a stable connection between the vulcanized sealing rubber gasket 601 and the liquid flow switch 6. Next, the return spring 7 is placed inside the main protective tube 5, and then the liquid flow switch 6 is slidably assembled into the main protective tube 5, so that one end of the return spring 7 abuts against the top of the lower connector 4, and the other end of the return spring 7 abuts against the bottom of the liquid flow switch 6, completing the assembly of the return spring 7 and the liquid flow switch 6. Then, the one-way sealing sleeve 9 is fitted between the central tube 1 and the main protective tube 5, allowing the one-way sealing sleeve to... The inner wall of the casing 9 fits tightly against the outer wall of the central tube 1. Then, the top of the central tube 1 is connected to the connecting tube 2 by a threaded sealing connection, the top of the connecting tube 2 is connected to the upper connector 3, the top of the upper connector 3 is connected to the oil well pipe 11, the bottom of the central tube 1 is connected to the lower connector 4, and the lower connector 4 is connected to the main protective tube 5, ensuring that each connection part is sealed and coaxial. Finally, the assembled device is placed into the annular space between the casing 10 and the oil well pipe 11, and the device position is adjusted so that the device is below the wax point of the oil well, ensuring that the casing pressure fluid passage hole 8 and the fluid passage port 101 correspond to the wax point position, thus completing the assembly and installation of the device.

[0085] Pipeline connection stage: Seal the pump truck outlet pipeline to the wellhead casing 10 valve group, check the sealing of the connection, and ensure that there is no leakage in the hot water delivery pipeline. This provides a closed pipeline foundation for subsequent hot water pressurization injection and directional flow, and avoids the waste of resources or the impact on the operation effect caused by hot water leakage during the delivery process.

[0086] Hot water pressurization and injection stage: Start the pump truck and pressurize the pre-prepared hot water. The pressurized hot water is continuously injected into the casing 10 through the valve group of the wellhead casing 10. After the hot water is injected, it flows downward along the gap between the casing 10 and the main protective pipe 5 and gradually accumulates in the area above the one-way sealing sleeve 9. As the hot water is continuously injected, the water pressure in the casing 10 gradually increases.

[0087] Sealing and blocking stage: When the water pressure inside the casing 10 rises to the set value, the water pressure will continue to act on the outer circumference of the one-way sealing sleeve 9; since the one-way sealing sleeve 9 is made of elastic material, it will expand outward under the action of water pressure, and its outer wall will gradually fit tightly with the inner wall of the casing 10 to form a reliable sealing structure; this sealing structure can completely block the transmission path of hot water to the rock and oil layers below and around the casing 10, ensuring that all the injected hot water is used for subsequent dewaxing operations and avoiding waste of hot water;

[0088] During the flow channel opening phase: The water pressure inside the casing 10 remains at the set value, and the continuously injected hot water cannot be transported downwards. Instead, it enters the gap between the central pipe 1 and the connecting pipe 2 through the casing pressure through hole 8 at the mating part of the main protective pipe 5 and the connecting pipe 2. Subsequently, the hot water flows into the interior of the central pipe 1 through the through ports 101 on the central pipe 1, which correspond one-to-one with the casing pressure through holes 8, and precisely acts on the end of the through switch 6 facing the through port 101. The radial pressure generated by the hot water is converted into axial thrust. When the thrust overcomes the elastic force of the return spring 7, it pushes the through switch 6 to slide downwards along the axial direction of the central pipe 1, and the return spring 7 is compressed. As the through switch 6 slides, the through port 101 gradually opens until the through switch 6 slides to the preset stroke position, and the through port 101 is fully opened, forming a flow channel for hot water to enter the interior of the central pipe 1 and flow to the well pipe 11.

[0089] Dewaxing stage: After the fluid inlet 101 is fully opened, hot water continuously enters the interior of the central pipe 1 through the fluid inlet 101, flows upward along the central pipe 1, enters the connecting pipe 2 through the connection between the top of the central pipe 1 and the connecting pipe 2, and then enters the oil well pipe 11 through the internal channel of the upper connector 3; at this time, the pumping unit starts working normally, and pumps the hot water and crude oil mixture in the oil well pipe 11 upward together; during the upward flow of the mixture, it will pass through the wax deposits in the oil well. The hot water, with its own heat, can fully dissolve the wax adhering to the inner wall of the oil well pipe 11. At the same time, the flow impact of the mixture will wash down the dissolved wax and the undissolved wax deposits, which will be pumped out of the wellhead along with the mixture, thus achieving the dewaxing operation on the inner wall of the oil well pipe 11; throughout the process, the hot water can continuously and stably act on the wax deposits, ensuring the dewaxing effect;

[0090] Reset Phase: When the temperature of the mixed liquid discharged from the wellhead outlet pipeline approaches the same as the temperature of the injected hot water, it indicates that the wax on the inner wall of the well casing 11 has been fully removed. Maintain this state for a set time to consolidate the wax removal effect. Subsequently, shut down the pump truck and the valve group of the wellhead casing 10, and stop injecting hot water into the casing 10. The hot water in the casing 10 gradually drains out, and the water pressure decreases accordingly. When the water pressure drops below the set value, the one-way sealing sleeve 9 loses the thrust of the water pressure and contracts and resets under its own elastic restoring force, its outer wall separating from the inner wall of the main casing 5. Upon separation, the gap between the sleeve 10 and the main protective tube 5 is restored to unobstructed flow; simultaneously, the hot water thrust on the liquid transfer switch 6 disappears, and the reset spring 7 extends under its own elastic force, pushing the liquid transfer switch 6 to slide upward along the axial direction of the central tube 1 to reset; when the liquid transfer switch 6 resets to its initial position, the vulcanized sealing rubber gasket 601 on its outer periphery abuts tightly against the inner wall of the central tube 1 and seals against the liquid transfer port 101, closing the hot water flow channel; at this point, the entire dewaxing operation is completed, the device is restored to its initial assembly state, and can be reused for the next dewaxing operation.

[0091] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reverse circulation energy saving device for oil well paraffin removal, characterized in that, Includes a central tube (1), a main protective tube (5), a liquid transfer switch (6), a reset spring (7), connecting components, and sealing components; The central tube (1) has several liquid passage ports (101) inside. The two ends of the central tube (1) are respectively connected to the oil well pipe (11) and the main protective pipe (5) through the connecting component. The central tube (1) and the connecting component near the oil well pipe (11) are provided with a sleeve pressure liquid passage hole (8). The main protective tube (5) is sleeved outside the central tube (1), and an installation gap is formed between the main protective tube (5) and the central tube (1). The reset spring (7) is located in the installation gap. One end of the reset spring (7) is connected to the end of the main protective tube (5) near the bottom of the central tube (1), and the other end of the reset spring (7) is connected to the liquid transfer switch (6). The liquid transfer switch (6) is slidably assembled inside the main protective tube (5). The liquid transfer switch (6) is correspondingly arranged with the central tube (1). The sealing component is located between the liquid transfer switch (6) and the central tube (1). A one-way sealing component is provided between the main protective tube (5) and the central tube (1). A sleeve (10) is sleeved on the outside of the main protective tube (5), and a gap is formed between the sleeve (10) and the main protective tube (5).

2. The reverse circulation energy saving device for oil well paraffin removal according to claim 1, characterized in that, The connecting components include a connecting pipe (2), an upper connector (3), and a lower connector (4). The connecting pipe (2) is located between the top end of the central pipe (1) and the upper connector (3). The top end of the central pipe (1) is detachably and sealed to the connecting pipe (2). The top end of the connecting pipe (2) is detachably and sealed to the upper connector (3). The top end of the upper connector (3) is detachably and sealed to the oil well pipe (11). The lower connector (4) is located between the bottom end of the central tube (1) and the main protective tube (5). The bottom end of the central tube (1) is detachably and sealed to the lower connector (4). The lower connector (4) is detachably and sealed to the main protective tube (5). The pressure-filled liquid passage (8) is opened through the mating part of the central tube (1) and the connecting tube (2), and the pressure-filled liquid passage (8) is connected to the liquid passage (101) inside the central tube (1).

3. The reverse circulation energy-saving device for oil well dewaxing according to claim 2, characterized in that, The central pipe (1) and connecting pipe (2), the connecting pipe (2) and upper connector (3), the upper connector (3) and oil well pipe (11), the central pipe (1) and lower connector (4), and the lower connector (4) and main protective pipe (5) are all connected by threaded sealing, and the axes of each connection part coincide.

4. The reverse circulation energy-saving device for oil well dewaxing according to claim 1, characterized in that, The sealing component is a vulcanized sealing rubber pad (601), which is embedded on the outer periphery of the liquid flow switch (6) and is in close contact with the inner wall of the central tube (1).

5. The reverse circulation energy-saving device for oil well dewaxing according to claim 1, characterized in that, The one-way sealing component is a one-way sealing sleeve (9), which is fitted between the central tube (1) and the main protective tube (5). The bottom end of the one-way sealing sleeve (9) is sealed and connected inside the main protective tube (5).

6. The reverse circulation energy-saving device for oil well dewaxing according to claim 5, characterized in that, The liquid transfer switch (6) has a columnar structure. The liquid transfer switch (6) slides in cooperation with the inner wall of the main protective tube (5). The liquid transfer switch (6) can slide along the axial direction of the central tube (1). The sliding stroke of the liquid transfer switch (6) corresponds to the position of the liquid transfer port (101).

7. The reverse circulation energy-saving device for oil well dewaxing according to claim 6, characterized in that, The liquid inlets (101) are evenly distributed along the circumference and axial direction of the central tube (1), and the number of liquid inlets (101) is at least one. The pressure-filled liquid passage (8) and the liquid passage (101) are connected in a one-to-one correspondence, and the diameter of the pressure-filled liquid passage (8) is not greater than the diameter of the liquid passage (101).

8. The reverse circulation energy-saving device for oil well dewaxing according to claim 2, characterized in that, One end of the reset spring (7) abuts against the top of the lower connector (4), and the other end of the reset spring (7) abuts against the bottom of the liquid flow switch (6).

9. The reverse circulation energy-saving device for oil well dewaxing according to claim 1, characterized in that, The inner diameter of the main protective tube (5) is larger than the outer diameter of the central tube (1). The main protective tube (5) and the central tube (1) are coaxially arranged. The installation gap formed by the main protective tube (5) and the central tube (1) is used to accommodate the reset spring (7) and the one-way sealing sleeve (9).

10. A reverse circulation energy-saving method for oil well dewaxing, applied to the reverse circulation energy-saving device for oil well dewaxing as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Assembly device: Assemble the sealing component on the liquid transfer switch (6), and assemble the return spring (7) and the liquid transfer switch (6) in sequence in the installation gap between the main casing (5) and the central tube (1), so that one end of the return spring (7) abuts against the lower connector (4) and the other end of the return spring (7) abuts against the liquid transfer switch (6); seal the central tube (1) with the well pipe (11) and the main casing (5) through the connecting component, assemble the one-way sealing component between the central tube (1) and the main casing (5), complete the overall assembly of the device, and place the device in the annular space between the casing (10) and the well pipe (11) to ensure that the device is below the wax point; S2, Connecting Pipeline: Seal and connect the pump truck's water outlet pipeline to the wellhead casing (10) valve group; S3, Hot water pressurized injection: Start the pump truck and pressurize the hot water into the casing (10). The hot water flows along the gap between the casing (10) and the main protective pipe (5) and accumulates on one side of the one-way sealing component. S4, sealing and blocking: when the water pressure inside the sleeve (10) reaches the set value, the one-way sealing component is sealed by the water pressure; S5, the flow channel is opened: the continuously injected hot water enters the mating part of the central tube (1) and the connecting tube (2) through the pressure-filled liquid hole (8), and then acts on the liquid-filled switch (6) after being guided by the liquid port (101). The thrust generated by the water pressure overcomes the elastic force of the reset spring (7) and pushes the liquid-filled switch (6) to slide along the central tube (1) axially, and the liquid-filled port (101) is fully opened; S6. Wax removal operation: Hot water enters the interior of the central pipe (1) through the liquid port (101), and then enters the oil well pipe (11) through the connection part of the connecting component. The pumping unit works normally and pumps the hot water and crude oil mixture in the oil well pipe (11) upward together. The mixture passes through the wax point. S7. Operation reset: When the temperature of the wellhead outlet pipeline and the temperature of the injected hot water tend to be consistent, maintain the set time, and then shut down the pump truck and the casing (10) valve group; the water pressure in the casing (10) drops, the one-way sealing component resets, and the gap is restored to unobstructed; at the same time, the reset spring (7) elastically extends, and the reset spring (7) pushes the liquid switch (6) to reset, the sealing component fits and seals with the liquid outlet (101), and the device returns to the initial state.

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