Underground self-adaptive injection equipment for thick oil viscosity reducer

Abstract

An agent pipe is fixedly installed at the axis position in an injection pipe, an interlayer pipe is fixedly arranged between the inner wall of the injection pipe and the agent pipe, an agent undetermined cavity is formed between the interlayer pipe and the injection pipe, and a pressure difference sealing mechanism is installed on the surface of the injection pipe; a hollow guide head is fixedly arranged at the lower end of the injection pipe, agent outlet holes are formed in the two sides of the lower end of the agent pipe, and the pushing mechanism is used for controlling lifting of the stirring mechanism. The injection pipe can be prevented from collapsing and deforming due to pressure in the descending process, the service life is prolonged, in the descending process, the pressure difference sealing mechanism can seal the agent outlet hole all the time, thick oil is prevented from entering the agent outlet hole, the purity of the thick oil viscosity reducer is guaranteed, and in the downward moving process of the injection pipe, the pushing mechanism is used for driving the stirring mechanism to ascend and descend. The stirring mechanism can stir the thick oil mass, the resistance borne by the injection pipe in the descending process is reduced, and it is guaranteed that the injection pipe can move downwards smoothly.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of petroleum equipment, and particularly relates to a downhole self-adaptive injection device for a heavy oil viscosity reducer. BACKGROUND

[0002] At present, many oil production processes have been developed at home and abroad, such as a steam injection production process, a dilution oil viscosity reduction process, a heating viscosity reduction process, and an emulsification viscosity reduction process by mixing with a high-efficiency water-soluble viscosity reducer. However, due to regional differences, different oilfield blocks adopt different processes. The deep heavy oil production accounts for about 57% of the total production in China, and at present, the dilution oil viscosity reduction process is mainly used.

[0003] In the heavy oil production process, the injection of the viscosity reducer is a key link to realize the optimization of the flowability of the crude oil. However, the existing injection device has many technical bottlenecks, which restricts the improvement of the viscosity reduction effect and the production efficiency. The specific problems are as follows: The pipeline for injecting the viscosity reducer needs to be submerged to a specified position of the oil pipe. When descending to a depth of 500-1000 meters or more, the pipeline passes through the heavy oil like a very viscous glue. The heavy oil and the outer wall of the pipeline generate a large viscous friction force, which consumes most of the pushing force. When the pushing force exceeds the critical value, the pipeline will be spirally bent, which not only greatly increases the contact area and the friction force, but also may cause the pipeline to be completely “locked” in the well, which cannot advance or exit, thereby affecting the injection efficiency of the viscosity reducer. At the same time, the existing viscosity reducer pipeline uses the material strength of the pipeline itself to resist pressure, so it will be subjected to a large pressure. During the movement of the oil pipe, the viscosity reducer pipeline will be abraded, causing the pipe wall to be thinned. At this time, the structural strength will be reduced, so that deformation is easily caused, the service life is not high, and the outlet for injecting the agent is subjected to a large pressure, so that the heavy oil is easily entered into the pipeline, which will dilute the viscosity reducer, thereby affecting the viscosity reduction efficiency and accuracy of the subsequent different depth oil layers.

[0004] Therefore, the present application provides a downhole self-adaptive injection device for a heavy oil viscosity reducer to solve the above problems. SUMMARY

[0005] (I) Technical problems solved The present application provides a downhole self-adaptive injection device for a heavy oil viscosity reducer, which aims to solve the problems proposed in the background.

[0006] (II) Technical solutions To achieve the above object, the present application provides the following technical solutions: A downhole adaptive injection device for a heavy oil viscosity reducer includes an injection pipe for entering a tubing. A drug delivery pipe is fixedly installed at the axial center of the injection pipe. A sandwich pipe is fixedly installed between the inner wall of the injection pipe and the drug delivery pipe, forming a drug delivery cavity between the sandwich pipe and the injection pipe. Multiple drug delivery outlets communicating with the drug delivery cavity are uniformly and axially symmetrically distributed on the surface of the injection pipe. A differential pressure sealing mechanism is installed on the surface of the injection pipe. A flow sensor is fixedly installed at each of the drug delivery outlets. When the pressure inside the tubing is greater than the pressure inside the drug delivery cavity, the differential pressure sealing mechanism closes the drug delivery outlet; conversely, it opens the outlet. The injection tube is closed at both ends, with a hollow guide head fixed at the lower end. An extension hole is provided at the lower end of the guide head, and a stirring mechanism is installed inside the guide head. A support partition is fixedly installed at the lower end of the interlayer tube, sealing the lower end of the injection tube. Dispensing holes are provided on both sides of the lower end of the injection tube. A piston is fitted onto the surface of the injection tube. One-way solenoid valves are installed on the surface of the interlayer tube at the dispensing holes. A pushing mechanism is installed at the lower part of the support partition, controlling the lifting and lowering of the stirring mechanism. An anchor cable is fixedly connected to the bottom of the injection tube.

[0007] As a preferred technical solution of this application, the differential pressure sealing mechanism includes a sealing sleeve, a spring, and two retaining rings. The two retaining rings are fixedly sleeved side by side on the outer surface of the injection tube. The drug outlet and the sealing sleeve are both located between the two retaining rings. The spring and the sealing sleeve are both sleeved on the outer surface of the injection tube. The two ends of the spring are fixedly connected to the lower end of the sealing sleeve and the corresponding retaining ring, respectively. The lower outer end and the upper inner end of the sealing sleeve are respectively provided with a first annular groove and a second annular groove. A drive mechanism for controlling the rotation of the stirring mechanism is installed at the lower part of the jacketed tube. A flow hole communicating with the drug cavity is provided at the upper end of the surface of the jacketed tube.

[0008] As a preferred technical solution of this application, the stirring mechanism includes an ejector column and two stirring rods. The ejector column is inserted into the guide head through an extension hole. An annular plate is fixedly installed on the outer surface of the lower end of the ejector column. Receiving slots are symmetrically opened on both sides of the ejector column. The lower ends of the two stirring rods are respectively movably hinged to the lower ends of the two receiving slots. The upper ends of the stirring rods are movably hinged to the pull rods. The interior of the ejector column is a cavity. A lifting seat is provided at the upper end of the cavity. The upper ends of the two pull rods pass through the corresponding receiving slots and are movably hinged to the lifting seat. The pushing mechanism is used to drive the lifting seat and the ejector column to rise and fall.

[0009] As a preferred technical solution of this application, the jacking mechanism includes a slide cylinder, a first electric push rod, and a second electric push rod. The lower end of the slide cylinder is open, and the upper end of the ejector column is slidably installed inside the slide cylinder. The second electric push rod is rotatably installed inside the slide cylinder, and the piston shaft of the second electric push rod passes through the ejector column and is fixedly connected to the lifting seat. The first electric push rod is fixedly installed at the lower part of the support partition, and the piston shaft of the first electric push rod passes through the slide cylinder and is fixedly connected to the upper part of the first electric push rod.

[0010] As a preferred technical solution of this application, two limiting ring ribs are fixedly installed inside the slide cylinder, and a limiting ring is fixedly sleeved on the outer surface of the second electric push rod. The limiting ring is movably locked between the two limiting ring ribs. Both sides of the upper end of the ejector column are fixedly provided with protruding ribs. Slide grooves are opened on the inner sidewall of the slide cylinder at the positions of the protruding ribs. The protruding ribs are inserted into the corresponding slide grooves. Multiple vertically arranged toothed grooves are opened on the outer surface of the slide cylinder.

[0011] As a preferred technical solution of this application, the driving mechanism includes a motor, a driving gear and a driven gear. The motor is fixedly installed at the lower end of the inner cavity of the jacketed tube. The driving gear is fixedly connected to the output shaft of the motor. The driven gear is rotatably installed inside the jacketed tube. The convex teeth of the driven gear and the driving gear correspond to the tooth grooves of the slide cylinder. The driven gear and the driving gear mesh on both sides of the slide cylinder respectively.

[0012] As a preferred technical solution of this application, a pressure sensor is fixedly installed inside the guide head.

[0013] As a preferred technical solution of this application, a first booster pipe and a second booster pipe are installed on the upper part of the injection pipe. The first booster pipe and the second booster pipe are respectively connected to the drug tube and the drug waiting chamber, and the first booster pipe and the second booster pipe are connected to the booster pump.

[0014] As a preferred technical solution of this application, a support block is fixedly installed on the outer surface of the medicine tube at the upper end of the dispensing hole.

[0015] As a preferred technical solution of this application, the stirring rod has a blade-like structure.

[0016] (III) Beneficial Effects This invention effectively balances the pressure inside the injection tube and the oil pipe by injecting a pressure-maintaining liquid into the reagent waiting chamber, reagent tube, and jacketed tube. When the injection tube descends to a depth of 500-1000 meters in the oil pipe, the stable internal and external threads effectively prevent the injection tube from collapsing and deforming due to high pressure during descent. Compared with traditional injection tubes that rely on the strength of the material itself for pressure resistance, the injection tube with the structure of this invention can further increase pressure resistance, thereby extending its service life. During descent, since the pressure inside the oil pipe is greater than the pressure in the reagent waiting chamber, the differential pressure sealing mechanism can always keep the reagent outlet closed, preventing heavy oil from entering and ensuring the purity of the heavy oil viscosity reducer. This effectively ensures that the subsequent heavy oil viscosity reducer can accurately reduce viscosity in oil layers at different depths. Because heavy oil is prevented from entering the heavy oil viscosity reducer, the heavy oil viscosity reducer is maintained, allowing the high-purity heavy oil viscosity reducer to react with the heavy oil, thereby improving the efficiency and accuracy of heavy oil viscosity reduction. When the injection tube descends to the designated depth for viscosity reduction treatment, the pressure sensor detects the internal pressure of the tubing. A booster pump is used to increase the pressure inside the agent chamber and the agent tube, making it greater than the pressure of the corresponding oil layer in the tubing. Then, the one-way solenoid valve is opened, and the heavy oil viscosity reducer can be continuously injected from the agent outlet into the corresponding oil layer in the tubing. The operation is simple and improves the injection efficiency. During the descent of the injection pipe, the jacking mechanism drives the stirring mechanism to rise and fall. The stirring mechanism can stir the heavy oil mass, which plays a role in pushing upward and reducing the pressure of heavy oil on the head of the injection pipe. This reduces the resistance encountered by the injection pipe during the descent process, ensuring that the injection pipe can move down smoothly and complete the injection work smoothly in the high-pressure area of ​​the oil pipe. Attached Figure Description

[0017] Figure 1 A schematic diagram of a downhole adaptive injection device for heavy oil viscosity reducers; Figure 2 A cross-sectional view of a downhole adaptive injection device for heavy oil viscosity reducers; Figure 3 for Figure 2 Enlarged schematic diagram of the structure at point A in the middle; Figure 4 for Figure 2 Enlarged schematic diagram of the structure at point B; Figure 5 for Figure 2 Enlarged schematic diagram of the structure at point C; Figure 6 A structural diagram of the jacking mechanism of a downhole adaptive injection device for heavy oil viscosity reducers; Figure 7 This is a structural diagram of the drive mechanism of a downhole adaptive injection device for heavy oil viscosity reducers. In the picture: 100. Oil pipe; 200. Injection pipe; 201. Chemical outlet; 202. Flow sensor; 203. First booster pipe; 204. Second booster pipe; 205. Anchor cable; 210. Chemical waiting chamber; 211. One-way solenoid valve; 220. Jacketed pipe; 221. Flow hole; 300. Chemical pipe; 310. Discharge hole; 320. Support block; 330. Piston; 340. Support partition; 400. Differential pressure sealing mechanism; 410. Sealing sleeve; 411. First annular groove; 412. Second annular groove; 420. Retaining ring; 4 30. Spring; 500. Pushing mechanism; 510. Slide cylinder; 511. Slide groove opening; 512. Limiting ring rib; 520. First electric push rod; 530. Second electric push rod; 531. Limiting ring; 600. Guide head; 610. Pressure sensor; 620. Extension hole; 700. Drive mechanism; 710. Driving gear; 720. Driven gear; 800. Stirring mechanism; 810. Ejection tube column; 811. Receiving groove opening; 812. Protruding rib; 813. Annular plate; 820. Stirring rod; 830. Pull rod; 840. Lifting seat. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] See Figure 1 and Figure 2As shown, this invention provides a downhole adaptive injection device for heavy oil viscosity reducers, including an injection pipe 200 for entering a tubing 100. The tubing 100 is a pipe used in existing oil extraction technology, and it is vertical. The initial stage of the oil is heavy oil. The difficulty in heavy oil extraction lies in its high viscosity and poor fluidity. Viscosity reducers can reduce viscosity. To inject the heavy oil viscosity reducer, a reagent tube 300 is fixedly installed at the axial center inside the injection pipe 200. A sandwich tube 220 is fixedly provided between the inner wall of the injection pipe 200 and the reagent tube 300. The injection pipe 200, the sandwich tube 220, and the reagent tube 300 are all made of corrosion-resistant and high-pressure-resistant materials. A reagent waiting cavity 210 is formed between the sandwich tube 220 and the injection pipe 200. For the planned discharge of heavy oil viscosity reducer, the injection pipe 200 has multiple agent outlet holes 201 that are axially symmetrically and uniformly distributed on its surface, connecting to the agent waiting chamber 210. A differential pressure sealing mechanism 400 is installed on the surface of the injection pipe 200. A flow sensor 202 is fixedly installed at the position of the agent outlet hole 201 to monitor the flow rate of the heavy oil viscosity reducer, thereby determining the amount of heavy oil viscosity reducer discharged. This allows for precise viscosity reduction of the oil layer. When the pressure inside the oil pipe 100 is greater than the pressure inside the agent waiting chamber 210, the differential pressure sealing mechanism 400 closes the agent outlet hole 201 to prevent heavy oil from entering the agent waiting chamber 210. Conversely, it leaves the agent outlet hole 201, at which point the heavy oil viscosity reducer can be injected into the oil layer. To ensure sealing, the... The injection tube 200 is closed at both ends. A hollow guide head 600 is fixedly installed at the lower end of the injection tube 200. The guide head 600 can be designed as a bullet or a cone shape. The guide head 600 is made of corrosion-resistant and high-pressure-resistant material. To agitate the heavy oil layer and allow the injection tube 200 to descend more smoothly, an extension hole 620 is opened at the lower end of the guide head 600. A stirring mechanism 800 is installed inside the guide head 600. A support partition 340 is fixedly installed at the lower end of the jacketed tube 220, which closes the lower end of the reagent tube 300. Discharge holes 310 are opened on both sides of the lower end of the reagent tube 300. A piston 330 is sleeved on the surface of the reagent tube 300. Heavy oil viscosity reducer is injected into the pipe 220 through the outlet hole 310. The piston is then pushed upward to squeeze out the oil used for pressure maintenance in the pipe 220. One-way solenoid valves 211 are installed on the surface of the pipe 220 at the outlet hole 310. A pushing mechanism 500 is installed at the lower part of the support partition 340. The pushing mechanism 500 is used to control the lifting and lowering of the stirring mechanism 800. An anchor cable 205 is fixedly connected to the bottom of the injection pipe 200. The other end of the anchor cable 205 is connected to a winch on the ground. The depth of descent of the injection pipe 200 in the oil pipe 100 can be controlled by the winch, so that the injection pipe 200 can release the heavy oil viscosity reducer in the oil layer at a specified depth.

[0020] Specifically, to achieve adaptive filling and discharging operation of the reagent-determining cavity 210, refer to... Figure 3As shown, in this embodiment, the differential pressure sealing mechanism 400 includes a sealing sleeve 410 made of corrosion-resistant metal, a spring 430, and two retaining rings 420. The two retaining rings 420 are fixedly sleeved side by side on the outer surface of the injection tube 200 and connected by welding. The agent outlet 201 and the sealing sleeve 410 are both located between the two retaining rings 420. The spring 430 and the sealing sleeve 410 are both sleeved on the outer surface of the injection tube 200. The gap between the sealing sleeve 410 and the injection tube 200 meets the sealing requirements. The two ends of the spring 430 are fixedly connected to the lower end of the sealing sleeve 410 and the corresponding retaining ring 420, respectively. The spring 430 acts as an elastic force, and under equal pressure, it can lift the closed sleeve 410 to close the medicine outlet 201. The lower outer end and the upper inner end of the closed sleeve 410 are respectively provided with a first annular groove 411 and a second annular groove 412. The cross-section of the first annular groove 411 is a right triangle, and its slope is inclined to the position of the medicine outlet 201. The lower part of the jacketed tube 220 is equipped with a drive mechanism 700 for controlling the rotation of the stirring mechanism 800. The upper surface of the jacketed tube 220 is provided with a flow hole 221 that connects to the medicine waiting cavity 210 for the discharge of liquid in the medicine tube 300.

[0021] See Figure 4 and Figure 6As shown, since the injection pipe 200 encounters significant resistance from heavy oil during its descent, and if the heavy oil is in a nearly solidified clump, the injection pipe 200 will have even greater difficulty in descent. To ensure the smooth descent of the injection pipe 200, in this embodiment, the stirring mechanism 800 includes an ejector column 810 and two stirring rods 820. Both the ejector column 810 and the stirring rods 820 are made of high-strength, corrosion-resistant alloy material. The lower end of the ejector column 810 is conical or circular, which can better break up clumps of heavy oil. The ejector column 810 is inserted into the guide head 600 through an extension hole 620. An annular plate 813 is fixedly installed on the outer surface of the lower end of the ejector column 810, which can be used to close the extension hole 620. The ejector column 810 has axially symmetrical receiving slots 811 on both sides, which can be used to receive the stirring rods 820. The lower ends of the two stirring rods 820 are respectively hinged. The stirring rod 820 is connected to the lower end of the two receiving slots 811. The upper end of each stirring rod 820 is movably hinged with a pull rod 830. The pull rod 830 is used to push and pull the stirring rod 820 to deflect. The ejector column 810 has a cavity inside. The upper end of the cavity is provided with a lifting seat 840. The upper ends of the two pull rods 830 pass through the corresponding receiving slots 811 and are movably hinged to the lifting seat 840. The push mechanism 500 is used to drive the lifting seat 840 and the ejector column 810 to rise and fall. First, the ejector column 810 is lowered so that the stirring rod 820 is exposed to the guide head 600 and makes it contact the heavy oil. Then, the lifting seat 840 is controlled to move down. When the lifting seat 840 moves down, it will push the stirring rod 820 to deflect through the pull rod 830, so that the two stirring rods 820 are in an open state. When the ejector column 810 rotates, the heavy oil clump can be stirred by the stirring rod 820, reducing the resistance encountered by the injection pipe 200 during the descent process.

[0022] See Figure 6 As shown, in this embodiment, to achieve asynchronous descent of the ejector column 810 and the lifting seat 840, allowing the stirring rod 820 to open smoothly outside the guide head 600, the pushing mechanism 500 includes a slide cylinder 510, a first electric push rod 520, and a second electric push rod 530. The lower end of the slide cylinder 510 is open, and the upper end of the ejector column 810 is slidably installed inside the slide cylinder 510. Specifically, the upper end of the ejector column 810 is movably inserted into the opening of the slide cylinder 510. To ensure that the ejector column 810 is in the opening process or in the open state when the stirring rod 820 is in the open state, the ejector column 810... The second electric push rod 530 is rotatably installed inside the slide cylinder 510. The piston shaft of the second electric push rod 530 passes through the ejector column 810 and is fixedly connected to the lifting seat 840. The first electric push rod 520 is fixedly installed at the lower part of the support partition 340. The piston shaft of the first electric push rod 520 passes through the slide cylinder 510 and is fixedly connected to the upper part of the first electric push rod 520. The ejector column 810 can be raised and lowered by activating the first electric push rod 520, and the lifting seat 840 can be raised and lowered by activating the second electric push rod 530. The two do not interfere with each other.

[0023] Inside the aforementioned interlayer tube 220, below the support partition 340, is installed a lithium-ion battery for power supply and a circuit board for control. The circuit board can be connected to the ground operating platform via a high-strength cable to start and stop the electric push rod, solenoid valve, and other electrical components. The battery is used to power the aforementioned electrical components, and its wiring is waterproofed. This part is existing technology and will not be described in detail here.

[0024] Furthermore, to prevent the second electric push rod 530 from detaching from the slide cylinder 510 while ensuring its smooth rotation, in this embodiment, two limiting ring ribs 512 are fixedly installed inside the slide cylinder 510, and a limiting ring 531 is fixedly sleeved on the outer surface of the second electric push rod 530. The limiting ring 531 is movably locked between the two limiting ring ribs 512, and its contact part is filled with lubricating grease to reduce friction. At the same time, in order to enable the ejector column 810 to rise and fall smoothly, protruding ribs 812 are fixedly provided on both sides of the upper end of the ejector column 810. Slide grooves 511 are opened on the inner side wall of the slide cylinder 510 at the positions of the protruding ribs 812. The length of the slide grooves 511 is required to allow the ejector column 810 to descend until its stirring mechanism 800 is completely exposed outside the guide head 600. The protruding ribs 812 are inserted into the corresponding slide grooves 511. In order to enable the slide cylinder 510 to be driven by the drive mechanism 700 to rotate, since the slide cylinder 510 is pushed by the first electric push rod 520 to move, it cannot be driven by a normal motor. Therefore, multiple vertically arranged toothed grooves are opened on the outer surface of the slide cylinder 510.

[0025] Based on the above, in order for the slide cylinder 510 to be able to rotate smoothly during the lifting and lowering process and also be driven by the drive mechanism 700, refer to... Figure 7 As shown, in this embodiment, the driving mechanism 700 includes a motor, a driving gear 710, and a driven gear 720. The driving gear 710 and the driven gear 720 are located on both sides of the slide cylinder 510. The motor is fixedly installed inside the lower end of the interlayer tube 220. The driving gear 710 is fixedly connected to the output shaft of the motor. The driven gear 720 is rotatably installed inside the interlayer tube 220. The convex teeth of the driven gear 720 and the driving gear 710 correspond to the tooth grooves of the slide cylinder 510. The driven gear 720 and the driving gear 710 mesh on both sides of the slide cylinder 510. By starting the motor, the motor can drive the slide cylinder 510 to rotate through the driving gear 710, while the driven gear 720 plays an auxiliary role to prevent the lateral position of the slide cylinder 510 from shifting, so that its tooth groove can always mesh with the driving gear 710.

[0026] Furthermore, in order to monitor the pressure value inside the oil pipe 100 in real time, ground personnel can monitor the pressure parameters in real time and determine whether pressurization is needed based on the pressure value. In this embodiment, a pressure sensor 610 is fixedly installed inside the guide head 600.

[0027] Furthermore, in this embodiment, a first pressurizing pipe 203 and a second pressurizing pipe 204 are installed on the upper part of the injection pipe 200. The first pressurizing pipe 203 and the second pressurizing pipe 204 are respectively connected to the drug pipe 300 and the drug waiting chamber 210. The first pressurizing pipe 203 and the second pressurizing pipe 204 are connected to a pressurizing pump. The first pressurizing pipe 203 is also connected to a pressurizing device for heavy oil viscosity reducer for filling in the heavy oil viscosity reducer.

[0028] Furthermore, to prevent the piston 330 from falling to the lower end of the drug tube 300 and blocking the dispensing hole 310, please refer to... Figure 5 As shown, in this embodiment, a support block 320 is fixedly installed on the outer surface of the drug tube 300 at the upper end of the dispensing hole 310 to support its piston 330 and ensure that it is positioned above the dispensing hole 310.

[0029] In this embodiment, the stirring rod 820 has a blade-like structure, specifically a curved or twisted shape. During rotation, the stirring rod 820 can push the oil layer inside the oil pipe 100 upward, so that the injection pipe 200 can be subjected to a downward force, increasing the diving speed of the injection pipe 200. At the same time, the stirring rod 820 can also break up the heavy oil clumps and reduce resistance.

[0030] The specific operating steps are as follows: The injection pipe 200 is lowered into the oil pipe 100 via the anchor cable 205. The descent speed and depth of the anchor cable 205 are controlled by a winch on the ground, effectively determining the submersion depth of the injection pipe 200. Before the injection pipe 200 is placed into the oil pipe 100, pressure-maintaining liquid is injected into the reagent waiting chamber 210, reagent pipe 300, and interlayer pipe 220 to prevent collapse and deformation due to pressure during descent. During descent, because the pressure inside the oil pipe 100 is greater than the pressure in the reagent waiting chamber 210, the pressure differential sealing mechanism 400 can always keep the reagent outlet 201 closed to prevent oil from entering. During the submersion process, a heavy oil viscosity reducer is injected into the reagent pipe 300 under high pressure through the first pressurization pipe 203. At this time, the piston 330... The tube will move upward, allowing the pressure-holding liquid in the agent tube 300 to be discharged into the agent waiting chamber 210 through the flow hole 221. Then, the pressure in the agent waiting chamber 210 will be increased through the second pressurizing tube 204, making its pressure greater than the pressure inside the oil pipe 100. This will smoothly push the closed sleeve 410 downward, exposing the agent outlet 201 and allowing the pressure-holding liquid to be discharged. When the injection tube 200 descends to the designated depth for viscosity reduction treatment, the pressure sensor 610 detects the internal pressure of the oil pipe 100. The pressure is increased through the first pressurizing tube 203 and the second pressurizing tube 204, making the pressure inside the agent waiting chamber 210 and the agent tube 300 greater than the corresponding oil layer pressure in the oil pipe 100. Then, the one-way solenoid valve 211 is opened, and the heavy oil viscosity reducer can be continuously sprayed from the agent outlet 201 into the corresponding oil layer in the oil pipe 100. During the downward movement of the injection pipe 200, the jacking mechanism 500 drives the lifting seat 840 and the ejector string 810 to rise and fall. First, the ejector string 810 is lowered, exposing the stirring rod 820 to the guide head 600 so that it contacts the heavy oil. Then, the lifting seat 840 is controlled to move downward. When the lifting seat 840 moves downward, it will push the stirring rod 820 to deflect through the pull rod 830, so that the two stirring rods 820 are in an open state. When the ejector string 810 rotates, the heavy oil clump can be stirred by the stirring rod 820, reducing the resistance encountered by the injection pipe 200 during the downward movement.

[0031] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A downhole adaptive injection device for heavy oil viscosity reducers, comprising an injection pipe for entering the tubing, characterized in that: A drug tube is fixedly installed at the center of the injection tube's interior axis. A sandwich tube is fixedly installed between the inner wall of the injection tube and the drug tube, forming a drug-determined cavity between the sandwich tube and the injection tube. Multiple drug outlet holes communicating with the drug-determined cavity are evenly and axially symmetrically distributed on the surface of the injection tube. A differential pressure sealing mechanism is installed on the surface of the injection tube. A flow sensor is fixedly installed at each drug outlet hole. When the pressure inside the oil pipe is greater than the pressure inside the drug-determined cavity, the differential pressure sealing mechanism closes the drug outlet hole; conversely, it disengages from the drug outlet hole. The upper and lower ends of the injection tube are... The injection tube is closed, with a hollow guide head fixed at its lower end. The guide head has an extension hole at its lower end and a stirring mechanism installed inside. A support partition is fixedly installed at the lower end of the interlayer tube, sealing the lower end of the drug tube. Dispensing holes are opened on both sides of the lower end of the drug tube. A piston is fitted on the surface of the drug tube. One-way solenoid valves are installed on the surface of the interlayer tube at the dispensing holes. A pushing mechanism is installed at the lower part of the support partition to control the raising and lowering of the stirring mechanism. An anchor cable is fixedly connected to the bottom of the injection tube.

2. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 1, characterized in that: The differential pressure sealing mechanism includes a sealing sleeve, a spring, and two retaining rings. The two retaining rings are fixedly sleeved side by side on the outer surface of the injection tube. The drug outlet and the sealing sleeve are both located between the two retaining rings. The spring and the sealing sleeve are both sleeved on the outer surface of the injection tube. The two ends of the spring are fixedly connected to the lower end of the sealing sleeve and the corresponding retaining ring, respectively. The lower outer end and the upper inner end of the sealing sleeve are respectively provided with a first annular groove and a second annular groove. A drive mechanism for controlling the rotation of the stirring mechanism is installed at the lower part of the jacketed tube. A flow hole communicating with the drug waiting cavity is provided at the upper end of the surface of the jacketed tube.

3. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 2, characterized in that: The stirring mechanism includes an ejector column and two stirring rods. The ejector column is inserted into the guide head through an extension hole. An annular plate is fixedly installed on the outer surface of the lower end of the ejector column. Receiving slots are symmetrically opened on both sides of the ejector column. The lower ends of the two stirring rods are respectively movably hinged to the lower ends of the two receiving slots. Each stirring rod has a tie rod movably hinged to its upper end. The ejector column is hollow inside, and a lifting seat is provided at the upper end of the cavity. The upper ends of the two tie rods pass through the corresponding receiving slots and are movably hinged to the lifting seat. The pushing mechanism is used to drive the lifting seat and the ejector column to rise and fall.

4. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 3, characterized in that: The jacking mechanism includes a slide cylinder, a first electric push rod, and a second electric push rod. The lower end of the slide cylinder is open, and the upper end of the ejector column is slidably installed inside the slide cylinder. The second electric push rod is rotatably installed inside the slide cylinder, and the piston shaft of the second electric push rod passes through the ejector column and is fixedly connected to the lifting seat. The first electric push rod is fixedly installed at the lower part of the support partition, and the piston shaft of the first electric push rod passes through the slide cylinder and is fixedly connected to the upper part of the first electric push rod.

5. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 4, characterized in that: Two limiting ring ribs are fixedly installed inside the slide cylinder. A limiting ring is fixedly sleeved on the outer surface of the second electric push rod. The limiting ring is movably locked between the two limiting ring ribs. Both sides of the upper end of the ejector column are fixedly provided with protruding ribs. The inner side wall of the slide cylinder is provided with sliding grooves at the positions of the protruding ribs. The protruding ribs are inserted into the corresponding sliding grooves. Multiple vertically arranged toothed grooves are provided on the outer surface of the slide cylinder.

6. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 5, characterized in that: The driving mechanism includes a motor, a drive gear, and a driven gear. The motor is fixedly installed inside the lower end of the sandwich tube. The drive gear is fixedly connected to the output shaft of the motor. The driven gear is rotatably installed inside the sandwich tube. The convex teeth of the driven gear and the drive gear correspond to the tooth grooves of the slide tube. The driven gear and the drive gear mesh on both sides of the slide tube respectively.

7. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 1, characterized in that: A pressure sensor is fixedly installed inside the guide head.

8. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 1, characterized in that: The injection tube is equipped with a first booster tube and a second booster tube at its upper part. The first booster tube and the second booster tube are respectively connected to the drug tube and the drug waiting chamber. The first booster tube and the second booster tube are connected to the booster pump.

9. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 1, characterized in that: A support block is fixedly installed on the outer surface of the medicine tube at the upper end of the dispensing hole.

10. The downhole adaptive injection device for heavy oil viscosity reducer according to claim 3, characterized in that: The stirring rod has a blade-like structure.

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