Ground quality-divided and pressure-divided injection allocation device for chemical flooding separate injection well

Abstract

The invention relates to the technical field of tertiary oil recovery, in particular to a ground quality-divided and pressure-divided injection allocation device for a chemical flooding separate injection well. Comprising an injection allocation pipe, a liquid inlet pipe section is vertically connected to the upper end of the injection allocation pipe, and a sealing cavity is formed in the lower portion of the injection allocation pipe. The injection allocation pipe and the outside of the sealing cavity are pressed and fixed through a fixing ring, and the lower portion of the sealing cavity is in threaded connection with a connecting pipe which is in threaded connection with the machine base. A transmission ring is arranged in the center in the machine base; a bearing is installed between the transmission ring and the machine base. A telescopic rod penetrates through the injection allocation pipe, and the upper portion of the telescopic rod is connected with an adjusting element. The lower end of the telescopic rod is in threaded connection with an inner hole of the transmission ring; a feedback limiting assembly is arranged between the connecting pipe and the telescopic rod; the transmission ring is connected with a manual piece or an automatic control assembly. According to the ground quality-divided and pressure-divided injection allocation device for the chemical flooding separate injection well, the problem that dual effective control over the molecular weight and the injection amount of a polymer is difficult to achieve in the quality-divided injection process or the pressure-divided injection process is solved.

Description

Technical Field

[0001] The invention relates to the technical field of tertiary oil recovery, in particular to a surface quality- and pressure-differentiated injection device for chemical flooding injection wells. Background Art

[0002] As major domestic oilfield development enters the middle and late stages, the proportion of tertiary oil recovery in annual production continues to increase, and the number of chemical flooding injection wells is rising year by year. Depending on the injection needs of chemical flooding, the injection flow rate and polymer molecular weight of different injection wells vary; the injection flow rate and molecular weight of different injection layers within a single injection well also vary slightly. Therefore, on the surface, injection stations must be equipped with separate injection pumps and supporting processes for different injection wells. Downhole, different models of pressure or molecular weight regulators must be configured for each injection layer to meet the injection needs of different injection wells and different injection layers, resulting in high initial investment costs.

[0003] A surface-based, mass- and pressure-based injection system can be installed in an injection station. By replacing the flow or molecular weight adjustment mechanism within the system, a single injection pump can be used to provide mass- and pressure-based injection for multiple chemical flooding injection wells, significantly reducing surface construction costs. Furthermore, since two-layer injection wells are a common feature of oil fields, downhole concentric dual-pipe injection can be used for these two-layer wells. Using a surface-based, mass- and pressure-based injection system at the wellhead to match the appropriate injection flow or molecular weight to the two layers significantly reduces testing and adjustment complexity and reduces testing costs.

[0004] Currently, surface-based, mass- and pressure-adjusted injection devices used for chemical flooding include: (1) a surface molecular weight adjustment device for chemical flooding injection wells (Patent No. 201711187104.8); and (2) a polymer molecular weight adjustment device (Patent No. 201220625323.6). Both patents require that the entire well be shut down for injection, followed by component disassembly and replacement to adjust polymer molecular weight or flow rate. The devices lack any built-in components for manual or automated control during the injection process. Furthermore, the molecular weight adjustment device described in "A surface molecular weight adjustment device for chemical flooding injection wells" has numerous right-angle turns, while the molecular weight adjustment device described in "Polymer molecular weight adjustment device" uses porous media elements to adjust polymer molecular weight. In mass-based injection, where the viscosity-average molecular weight (MW) of the injected polymer is adjusted using a separate injection tool, the goal is to reduce the polymer molecular weight while maintaining the injection flow rate of the polymer solution. Significant pressure loss occurs when the polymer solution flows through the right-angle turns and porous media elements, reducing the injection pressure and making it impossible to inject a sufficient volume of polymer solution into the formation per unit time. During partial pressure injection, the goal is to minimize the injection volume while maximizing the molecular weight of the polymer solution. When the polymer solution flows through right-angle bends and porous media elements, it experiences a strong shear effect, which causes polymer molecular chains to break, resulting in a decrease in molecular weight and a negative impact on the chemical flooding effect. Therefore, the aforementioned patents struggle to achieve effective dual control of polymer molecular weight and injection volume, whether during partial pressure injection or partial pressure injection. Summary of the Invention

[0005] The present invention proposes a surface mass-separated and pressure-separated injection device for chemical flooding injection wells to solve the problem that it is difficult to achieve dual effective control of polymer molecular weight and injection volume during both mass-separated injection and pressure-separated injection. The purpose of the present invention patent is to propose a chemical flooding surface injection tool that can achieve manual or automatic control of the injected molecular weight or flow rate during the injection process. The tool has fewer interception structures such as right-angle turns inside the tool, which can effectively prevent the polymer from encountering interception shear and causing molecular weight reduction. During mass-separated injection, it can achieve the goal of minimizing flow loss while regulating the polymer molecular weight. During pressure-separated injection, it can effectively control the injection flow rate while minimizing polymer molecular weight loss, thereby ensuring the chemical flooding displacement effect.

[0006] The present invention provides a surface quality and pressure distribution injection device for chemical drive injection wells, comprising an injection pipe, wherein the upper end of the injection pipe is vertically connected to a liquid inlet pipe section, the lower part of which is provided with a sealed chamber, the injection pipe and the outside of the sealed chamber are compressed and fixed by a fixing ring; the lower part of the sealed chamber is threadedly connected to a connecting pipe; the connecting pipe is threadedly connected to a machine base, the center of the machine base is provided with a transmission ring; a bearing is installed between the transmission ring and the machine base; a telescopic rod is passed through the injection pipe, the upper part of the telescopic rod is threadedly connected to an adjusting element; the lower end of the telescopic rod is threadedly connected to the inner hole of the transmission ring; a feedback limit assembly is arranged between the connecting pipe and the telescopic rod; the transmission ring is connected to a manual part or an automatic control assembly.

[0007] Preferably, the feedback limit assembly disposed between the connecting tube and the telescopic rod includes a magnetic proximity sensor and a magnet; the magnetic proximity sensor is connected to the inner thread of the connecting tube, and a magnet is installed on the telescopic rod. When the prime mover drives the telescopic rod to extend or retract to the upper or lower limit, the magnetic proximity sensor can feedback a limit signal.

[0008] Preferably, a square limit block is fixed in the center groove of the lower end surface of the sealing cavity by screws, and a square groove is processed on one side of the middle shaft section of the telescopic rod, and the square groove cooperates with the square limit block to limit the circumferential rotation of the telescopic rod; two circular grooves are processed at a preset distance on the other side of the middle shaft section of the telescopic rod symmetrical to the square groove, and magnets are installed in the circular grooves.

[0009] Preferably, the center hole at the upper end of the telescopic rod is threadedly connected to the adjusting element; a straightening ring is nested outside the upper end of the telescopic rod, and the adjusting element presses and fixes the straightening ring to the upper end of the telescopic rod.

[0010] Preferably, the regulating element is a pressure-dividing injection regulating element or a mass-dividing injection regulating element; The molecular weight regulating injection regulating element is composed of a number of molecular weight regulating core monomers connected in sequence; the bottom of each molecular weight regulating core monomer is a molecular weight regulating core base, and the top is a molecular weight regulating core with an arc-shaped outer wall; the end of the molecular weight regulating core base is threadedly connected to the telescopic rod; the molecular weight regulating core of the first section of the monomer is connected to the molecular weight regulating core straightening body; The partial pressure injection regulating element is formed by connecting a number of throttling core monomers in sequence; the bottom of each throttling core monomer is a throttling core base, and the top is a throttling core with a corrugated outer wall; the end of the terminal throttling core base is threadedly connected to the telescopic rod; the throttling core of the first section monomer is connected to the throttling core straightening body.

[0011] Preferably, the automatic control component connected to the transmission ring is a worm gear reduction box, the transmission ring and the worm gear reduction box are connected by a key and fixed by a retaining spring; a prime mover is installed on the worm gear reduction box, and the prime mover is a stepping motor, a servo motor, a hydraulic motor, etc.; the prime mover drives the adjustment element on the telescopic rod to extend and retract; The manual part connected to the transmission ring is a hand wheel or a manual wheel assembly.

[0012] Preferably, the worm gear reduction box is connected to the manual wheel assembly; the manual wheel assembly is inserted into the input hole of the worm gear reduction box through the manual wheel transmission shaft.

[0013] Preferably, a T-type transmission thread is machined on the shaft section on the side of the telescopic rod in contact with the transmission ring, which cooperates with the T-type transmission thread machined on the inner hole of the transmission ring; and the machine base is connected to the worm gear reducer by bolts.

[0014] Preferably, the injection pipe and the fixed ring, the sealing cavity and the connecting pipe, and the connecting pipe and the machine base are fixed by screws; an O-ring is placed between the injection pipe and the lower sealing cavity; a Y-ring is placed between the sealing cavity and the telescopic rod; and the sealing lip of the Y-ring faces the direction of the incoming liquid.

[0015] Preferably, the bearings installed between the transmission ring and the machine base are thrust ball bearings and deep groove ball bearings.

[0016] The present invention has at least the following beneficial effects: 1. This invention proposes a surface-based, quality- and pressure-differentiated injection device for chemical flooding wells. The device is designed with components suitable for manual or automated control. A handwheel can be mounted directly on the drive ring, or a prime mover such as a stepper motor, servo motor, or hydraulic motor can be mounted on the worm gear reducer. This prime mover drives the adjustment element on the telescopic rod to extend and retract. A magnet is mounted on the telescopic rod, and a magnetic proximity sensor is mounted on the connecting pipe. When the prime mover drives the telescopic rod to extend or retract to the upper or lower limit positions, the magnetic proximity sensor provides feedback of the limit signals.

[0017] 2. The polymer solution flows through only one right-angle bend in the device, and the flow path is short, which can effectively avoid the pressure loss and polymer shear viscosity reduction effect caused by too many right-angle bends.

[0018] 3. The external design of the regulating element is a streamlined outer wall structure. The multi-stage regulating elements are connected by threads, and the flow rate is controlled by reducing the cross-sectional area during the flow of the polymer fluid.

[0019] The present invention features a rational structure, enabling manual or automated control of the injection process. With fewer internal right-angle turns, it can regulate polymer flow rate and molecular weight while minimizing viscosity loss or throttling pressure differential. This enables automated surface-based, mass- and pressure-differentiated injection in chemical flooding wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into and constitute a part of the specification. These drawings illustrate embodiments consistent with the present invention and, together with the specification, are used to explain the technical solutions of the present invention.

[0021] Figure 1 This is a structural diagram of the surface quality and pressure distribution injection device of the present invention; Figure 2 It is a structural schematic diagram of the telescopic rod of the present invention; Figure 3 for Figure 2 Bottom view of Figure 4 for Figure 2 A top view of Figure 5 This is a schematic structural diagram of the fractional injection regulating element of the present invention; Figure 6 This is a schematic structural diagram of the molecular weight regulating core monomer of the present invention; Figure 7 This is a schematic structural diagram of the partial pressure injection regulating element of the present invention; Figure 8 It is a structural schematic diagram of the throttling core monomer of the present invention.

[0022] In the figure: 1-dispensing pipe, 2-adjusting element, 3-centering ring, 4-telescopic rod, 5-Y-type sealing ring, 6-O-type sealing ring, 7-fixing ring, 8-sealing chamber, 9-square limit block, 10-connecting pipe, 11-magnetic proximity sensor, 12-magnet, 13-machine base, 14-transmission ring, 15-thrust ball bearing, 16-deep groove ball bearing, 17-worm gear reduction box, 18-hexagon socket head screw, 19-manual wheel assembly, 20-liquid inlet pipe section, 21-square groove, 22-circular groove, 23-molecular weight regulating core, 24-molecular weight regulating core base, 25-throttling core, 26-throttling core base, 27-molecular weight regulating core centering body, 28-throttling core centering body. DETAILED DESCRIPTION

[0023] The present invention is further described below with reference to the accompanying drawings: like Figure 1 、 Figure 2As shown, a surface quality and pressure distribution injection device for chemical flooding injection wells includes an injection pipe 1 and a telescopic rod 4; the upper end of the injection pipe 1 is vertically welded with a liquid inlet pipe section 20, and the lower part is equipped with a sealed chamber 8; the injection pipe 1 and the outer part of the sealed chamber 8 are compressed and fixed by a fixing ring 7; the lower part of the sealed chamber 8 is threadedly connected to the connecting pipe 10; the connecting pipe is threadedly connected to the machine base 13, and a transmission ring 14 is installed in the center of the machine base 13; a thrust ball bearing 15 and a deep groove ball bearing 16 are installed between the transmission ring 14 and the machine base 13, wherein the main function of the thrust ball bearing 14 is to bear the axial load transmitted to the transmission ring 14 by the telescopic rod 4, and the function of the deep groove ball bearing is to support the transmission ring 14 Support is provided for rotational motion; a telescopic rod 4 is arranged in the internal ring cavity of the injection pipe 1, the sealing cavity 8, the connecting pipe 10, and the machine base 13, and the upper part of the telescopic rod 4 is connected to the adjusting element 2 by a thread; the lower end of the telescopic rod rests on the inner hole of the transmission ring 14 4 and is threadedly connected to the inner hole of the transmission ring 14; a T-type transmission thread is machined on the shaft section on the side of the telescopic rod 4 in contact with the transmission ring 14, which cooperates with the T-type transmission thread machined on the inner hole of the transmission ring; the center hole at the upper end of the telescopic rod 4 is threadedly connected to the adjusting element 2, and a straightening ring 3 is nested on the outside of the upper end of the telescopic rod 4, and the adjusting element presses and fixes the straightening ring; the square limit block 9 is fixed in the center groove of the lower end face of the sealing cavity 8 by a screw 18.

[0024] The transmission ring 14 is connected to a manual part or an automatic control component; the machine base 13 is connected to the worm gear reduction box 17 by bolts, and the transmission ring 14 and the worm gear reduction box 17 are connected by a key and fixed by a retaining spring; the worm gear reduction box 17 is connected to the manual wheel assembly 19; the manual wheel assembly 19 is inserted into the input hole of the worm gear reduction box 17 through the manual wheel drive shaft; or a handwheel is directly installed on the transmission ring 14; a prime mover such as a stepper motor, servo motor, hydraulic motor, etc. is installed on the worm gear reduction box; the adjusting element on the telescopic rod is driven to extend and retract by the prime mover.

[0025] An upper feedback limit assembly is placed between the connecting tube 10 and the telescopic rod; the feedback limit assembly includes a magnetic proximity sensor 11 and a magnet; the connecting tube 10 is internally threaded with the magnetic proximity sensor 11; Figure 2-4 As shown, a square groove 21 is machined on one side of the middle shaft section of the telescopic rod 4, and the square groove cooperates with the square limit block 9 to limit the circumferential rotation of the telescopic rod; two circular grooves 22 are machined at a preset distance on the other side of the middle shaft section of the telescopic rod symmetrical to the square groove, and magnets 12 are installed in the circular grooves; when the prime mover drives the telescopic rod to extend or retract to the upper or lower limit, the magnetic proximity sensor can feedback the limit signal.

[0026] The regulating element 2 is a pressure-dividing injection regulating element or a mass-dividing injection regulating element; the regulating element is designed with a streamlined outer wall structure, and the multi-stage regulating elements are connected by threads, and the flow rate is controlled by reducing the cross-sectional area during the flow of the polymer fluid.

[0027] Figure 5 、 Figure 6 As shown, the fractional injection regulating element is composed of several molecular weight regulating core monomers connected in sequence; the bottom of each molecular weight regulating core monomer is a molecular weight regulating core base 24, and the top is a molecular weight regulating core 23 with an arc-shaped outer wall; the end of the terminal molecular weight regulating core base 24 is threadedly connected to the telescopic rod 4; the molecular weight regulating core 23 of the first section of the monomer is connected to the molecular weight regulating core straightening body 27.

[0028] Figure 7 、 Figure 8 As shown, the partial pressure injection regulating element is composed of several throttling core monomers connected in sequence; the bottom of each throttling core monomer is a throttling core base 26, and the top is a throttling core 25 with a corrugated outer wall; the end of the terminal throttling core base 26 is threadedly connected to the telescopic rod 4; the throttling core 25 of the first section monomer is connected to the throttling core straightening body 28.

[0029] When a polymer solution flows through the annular space formed by the pressure-regulating element and the inner wall of the injection pipe, the change in flow area causes the solution flow rate to change, thereby changing the injection flow rate. At the same time, the polymer molecular chains in the polymer solution are easily degraded by the change in flow rate. By repeatedly optimizing the outer wall structure of the pressure-regulating element, the current streamlined outer wall structural parameters have been formed, which minimizes the polymer degradation effect caused by changes in the flow rate of the polymer solution. The goal is to reduce the injection flow rate without reducing the polymer molecular weight. When a polymer solution flows through the annular space formed by the pressure-regulating element and the inner wall of the injection pipe, the outer wall structure is repeatedly optimized to maximize the polymer degradation effect caused by changes in the flow rate of the polymer solution, while minimizing the flow change caused by changes in flow area. The goal is to reduce the polymer molecular weight without reducing the injection flow rate.

[0030] The injection pipe 1 and the fixing ring 7, the sealing cavity 8 and the connecting pipe, and the connecting pipe and the machine base are fixed by screws; an O-ring 6 is placed between the injection pipe 1 and the lower sealing cavity 8; a Y-ring 5 is placed between the sealing cavity 8 and the telescopic rod 4; the sealing lip of the Y-ring faces the direction of the incoming liquid. When liquid comes into the liquid inlet, the pressure in the injection pipe cavity rises and is higher than the pressure in the sealing cavity. The Y-ring opens under the action of the pressure difference, and the sealing effect is further enhanced by the "self-sealing effect".

[0031] The working process of the surface quality and pressure distribution device for chemical flooding injection wells is as follows: The top opening of the injection pipe 1 is a liquid outlet channel; the liquid inlet pipe section 20 vertically connected to the upper end of the injection pipe 1 is a liquid inlet channel; the liquid inlet channel and the liquid outlet channel on the injection pipe 1 can be changed according to the outer dimension direction of the regulating element 2. If the direction of the throttling groove on the regulating element 2 is as follows: Figure 1 As shown, the flow channel perpendicular to the regulating element 2 is the liquid inlet, and the flow channel parallel to it is the liquid outlet. The throttle groove on the regulating element 2 can be modified to accommodate pressure-separated injection or mass-separated injection, depending on the injection requirements. The polymer solution flows into the inlet section of the injection pipe 1, passes through the regulating element 2 for throttling or mass separation, and then flows out of the liquid outlet. A thrust ball bearing 15 and a deep groove ball bearing 16 are mounted between the base 13 and the transmission ring 14, respectively. The thrust ball bearing 14 primarily bears the axial load transmitted to the transmission ring 14 by the telescopic rod 4, while the deep groove ball bearing 16 provides support for the rotational motion of the transmission ring 14. To adjust the injected polymer flow rate or molecular weight, an electric or hydraulic control system drives a prime mover, which in turn rotates the worm in the worm gear reducer. The worm is keyed to the transmission ring 14, and this rotation drives the transmission ring 14, which has a T-thread machined into its inner bore. A square stopper 9 is mounted on the sealed chamber 8 and extends into a square groove machined into the telescopic rod 4, limiting the circumferential rotational motion of the telescopic rod 4. The T-thread on the transmission ring 14 mates with the T-thread on the telescopic rod 4. By changing the direction of rotation of the prime mover, the telescopic rod 4 can be axially extended and retracted by the rotation of the transmission ring 14. The telescopic rod 4 is connected to the regulating element 2 through a threaded connection, and the straightening ring 3 is installed between the regulating element 2 and the telescopic rod 4 to play a straightening and supporting role. The regulating element 2 is processed with a throttling groove for pressure-dividing injection or mass-dividing injection. The axial extension and retraction of the regulating element 2 changes the number of regulating cores that the liquid inlet has to flow through. When the regulating core specification is the throttling core required for pressure-dividing injection, the more throttling cores the polymer solution flows through, the greater the pressure difference between the liquid outlet and the liquid inlet, and the less the injection volume per unit time. When the regulating core specification is the molecular weight regulating core required for mass-dividing injection, the more molecular weight regulating cores the polymer solution flows through, the more significant the shearing effect experienced by the polymer solution, and the lower the molecular weight of the polymer solution flowing out of the liquid outlet.

[0032] The device is designed with components suitable for manual or automated control. A handwheel can be mounted directly on the drive ring, or a prime mover such as a stepper motor, servo motor, or hydraulic motor can be installed on the worm gear reducer. This prime mover drives the adjustment element on the telescopic rod to extend and retract. A magnet is mounted on the telescopic rod, and a magnetic proximity sensor is installed on the connecting tube. When the prime mover drives the telescopic rod to extend or retract to the upper or lower limit, the magnetic proximity sensor provides feedback.

[0033] The polymer solution flows through only one right-angle bend in the device, namely the liquid inlet pipe section 20 vertically connected to the injection pipe 1. The flow path is short, which can effectively avoid pressure loss and polymer shear viscosity reduction effect caused by too many right-angle bends.

[0034] It should be noted that, in the description of the present invention, unless otherwise specified or limited, "installation" and "connection" should be understood in a broad sense. This includes but is not limited to direct connection, detachable connection, integral connection, mechanical connection, and welding. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are protected by the present invention. While various embodiments of the present invention have been described above, the above descriptions are intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A surface quality and pressure distribution injection device for chemical flooding injection wells, comprising an injection pipe (1), characterized in that: The upper end of the dispensing pipe (1) is vertically connected to a liquid inlet pipe section (20), and the lower part is provided with a sealing chamber (8). The dispensing pipe (1) and the sealing chamber (8) are externally pressed and fixed by a fixing ring (7); the lower part of the sealing chamber (8) is threadedly connected to a connecting pipe (10); the connecting pipe (10) is threadedly connected to a machine base (13), and a transmission ring (14) is installed in the center of the machine base (13); a bearing is installed between the transmission ring (14) and the machine base (13); a telescopic rod (4) is passed through the dispensing pipe, and the upper part of the telescopic rod (4) is threadedly connected to the adjusting element (2); the lower end of the telescopic rod is threadedly connected to the inner hole of the transmission ring (14); a feedback limit assembly is arranged between the connecting pipe (10) and the telescopic rod (4); the transmission ring (14) is connected to a manual part or an automatic control assembly.

2. A surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1, characterized in that: The feedback limit assembly disposed between the connecting tube (10) and the telescopic rod comprises a magnetic proximity sensor and a magnet; the magnetic proximity sensor is connected to the inner thread of the connecting tube, and a magnet is mounted on the telescopic rod; when the prime mover drives the telescopic rod to extend or retract to the upper or lower limit, the magnetic proximity sensor can feedback a limit signal.

3. A surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 2, characterized in that: A square limit block (9) is fixed in the center groove of the lower end surface of the sealing cavity (8) by screws. A square groove is machined on one side of the intermediate shaft section of the telescopic rod (4). The square groove cooperates with the square limit block (9) to limit the circumferential rotation of the telescopic rod. Two circular grooves are machined at a preset distance on the other side of the intermediate shaft section of the telescopic rod, which is symmetrical to the square groove. Magnets are installed in the circular grooves.

4. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1 is characterized in that: The center hole at the upper end of the telescopic rod (4) is threadedly connected to the adjusting element (2); a stabilizing ring (3) is nested outside the upper end of the telescopic rod (4), and the adjusting element (2) presses and fixes the stabilizing ring (3) on the upper end of the telescopic rod (4).

5. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1 is characterized in that: The regulating element (2) is a pressure-dividing injection regulating element or a mass-dividing injection regulating element; The fraction injection regulating element is formed by sequentially connecting a plurality of molecular weight regulating core monomers; the bottom of each molecular weight regulating core monomer is a molecular weight regulating core base (24), and the top is a molecular weight regulating core (23) with an arc-shaped outer wall; the end of the terminal molecular weight regulating core base (24) is threadedly connected to the telescopic rod; the molecular weight regulating core (23) of the first section of the monomer is connected to the molecular weight regulating core straightening body (27); The partial pressure injection regulating element is formed by sequentially connecting a plurality of throttling core monomers; the bottom of each throttling core monomer is a throttling core base (26), and the top is a throttling core (25) with a corrugated outer wall; the end of the terminal throttling core base (26) is threadedly connected to the telescopic rod; the throttling core (25) of the first section monomer is connected to the throttling core straightening body (28).

6. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1 is characterized in that: The automatic control assembly connected to the transmission ring (14) includes a worm gear reduction box (17), the transmission ring and the worm gear reduction box are connected by a key and fixed by a retaining spring; a prime mover is installed on the worm gear reduction box, and the prime mover is a stepping motor, a servo motor, or a hydraulic motor; the prime mover drives the adjustment element on the telescopic rod to extend and retract; The manual part connected to the transmission ring (14) is a hand wheel or a manual wheel assembly.

7. A surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 6, characterized in that: The worm gear reduction box (17) is connected to the manual wheel assembly; the manual wheel assembly is inserted into the input hole of the worm gear reduction box through the manual wheel transmission shaft.

8. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1 is characterized in that: The shaft section on the side of the telescopic rod (4) in contact with the transmission ring (14) is processed with a T-shaped transmission thread, which matches the T-shaped transmission thread processed on the inner hole of the transmission ring; the machine base (13) is connected to the worm gear reduction box (17) through bolts.

9. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1 is characterized in that: The injection pipe (1) and the fixing ring (7), the sealing cavity (8) and the connecting pipe (10), and the connecting pipe (10) and the machine base (13) are fixed by screws; an O-type sealing ring is arranged between the injection pipe and the lower sealing cavity; a Y-type sealing ring (5) is arranged between the sealing cavity (8) and the telescopic rod (4); and the sealing lip of the Y-type sealing ring faces the direction of the incoming liquid.

10. The surface quality and pressure distribution injection device for chemical flooding injection wells according to claim 1, characterized in that: The bearings installed between the transmission ring (14) and the machine base (13) are a thrust ball bearing (15) and a deep groove ball bearing (16).

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