A low shear conditioning device for a medicament injection well

Abstract

The application discloses a low-shear adjusting device for a medicament injection well, which comprises an adjusting valve, a Venturi pressure-reducing pipe I and a buffer valve cage, the adjusting valve is provided with an adjusting valve body and liquid inlets and outlets, the Venturi pressure-reducing pipe I is arranged in the adjusting valve body, the adjusting valve is further provided with an adjusting valve spool and a valve seat, a throttle orifice plate is arranged between the Venturi pressure-reducing pipe I and the valve seat, the upper rod body of the adjusting valve spool is connected with an electric actuator, the body of the adjusting valve spool is arranged in the buffer valve cage, the valve seat, the throttle orifice plate and the Venturi pressure-reducing pipe I, the throttle orifice plate is provided with flow guide holes, a flow-increasing valve is connected in parallel on one side of the adjusting valve, and the flow-increasing valve and the adjusting valve are connected through a cut-off valve; when the cut-off valve is opened, the medium in the adjusting valve through the liquid inlets can be injected into the well through the liquid outlets of the adjusting valve, so that the property of the injected medicament is prevented from being affected by mechanical shearing.

Description

Technical Field

[0001] This invention relates to wellhead production valves in the petroleum industry, and in particular to a low-shear regulating device for chemical injection wells. Background Technology

[0002] As offshore oilfield development progresses, waterflooding is facing increasing difficulties in maintaining stable production, rapidly rising costs, and declining profitability. Therefore, it is necessary to transform the development approach to improve oil production speed and recovery rate.

[0003] Chemical flooding is an important method to improve the recovery rate of water-driven oil reservoirs and has achieved good development results in onshore oil fields. Offshore oil reservoirs with low water cut, low recovery rates, abundant material resources, and great potential have the basic conditions for carrying out chemical flooding. In offshore oil fields, binary composite flooding, which involves injecting a mixture of water and chemical agents, can also achieve excellent extraction results.

[0004] In offshore oilfields, binary composite flooding typically employs a multi-well injection method with a single pump. The prepared ultra-high viscosity polymer mother liquor is pressurized by the injection pump, mixed with high-pressure produced water via a high-efficiency mixer, and finally distributed to each well via a low-shear regulating valve assembly (CPR). While the viscosity of the reagent at the wellhead meets design requirements, the following problems have been observed in its application:

[0005] First, it is impossible to achieve personalized adjustment of concentration in a single well: because the polymer injection process uses a method of mixing polymer mother liquor and produced water as a whole and then distributing it to each well, the concentration of the injected agent in all wells is the same, which makes it impossible to adjust the concentration of the injected agent in a single well according to the actual injection conditions of each well, thus restricting the development effect of polymer injection.

[0006] Second, there is a deviation between the agent concentration in a single well and the designed concentration: due to the fact that the overall mixing time between the agent and the produced water is less than 10 seconds and the influence of fluid flow deviation, the injection concentration of each well has a deviation of about 10%, which is not conducive to the precise control of injection quality.

[0007] Third, high-flow-rate injection wells experience significant polymer viscosity shear loss: due to the high injection volume per well in offshore oilfields, the flow rate controlled by low-shear regulating valves reaches up to 11 m³ / s. 3 / h, the high flow rate leads to a significant loss of viscosity in the polymer injected into the well.

[0008] To address the shortcomings of current low-shear regulating devices, adopting low-shear regulating valves in the production process of each polymer injection well can achieve separate preparation of polymer mother liquor, which can then be mixed with produced water for injection, resulting in better polymer injection development effects.

[0009] According to a survey of low-shear regulating valves for pharmaceutical mother liquor both domestically and internationally, commonly used low-shear regulating valves are generally suitable for pharmaceutical mother liquors with a concentration of 5000 mg / L and a viscosity of 1000-3000 mPa·s. However, there are no corresponding regulating devices for polymer mother liquors with extremely high viscosity. Therefore, there is an urgent need to develop and produce corresponding low-shear regulating valves for pharmaceutical injection to solve the problem in on-site production.

[0010] Searching reveals that the pressure drop structure of low-shear regulating valves currently used in chemical flooding is mainly of a single type. For example, Chinese patent CN103498645B discloses a low-shear regulating valve, including a valve body and a regulating device. The valve body includes an adjusting section and a valve cylinder arranged sequentially. The adjusting section contains a lead screw nut, which is fitted into a corresponding groove on the inner wall of the adjusting section and can rotate around its central axis within the groove. The regulating device includes an adjusting handle and an adjusting rod. The adjusting handle is fixed to the lead screw nut. The adjusting rod includes a mounting section and a rod body arranged sequentially. The mounting section is screwed onto the lead screw nut, and the rod body is located inside the valve cylinder, comprising multiple truncated cones connected end-to-end from front to back.

[0011] Because this invention is equipped with an adjustment handle and an adjustment rod, the adjustment rod can be moved back and forth by rotating the screw nut of the adjustment handle, thereby realizing the function of adjusting the flow rate by changing the cross-sectional area of ​​the flow channel. Moreover, the flow channel area changes gradually during the adjustment process, and the shear force generated is very small, which will not affect the use effect of the injected solution.

[0012] However, the aforementioned patented technology still has the following problems:

[0013] 1. Pressure reduction is limited by using a multi-stage truncated cone valve core and corresponding valve seat.

[0014] 2. The valve core is positioned by the upper packing and the bottom guide ring. There is no positioning in the middle of the valve core. The excessively long valve core is prone to vibration under high pressure differential, which leads to unstable operation.

[0015] 3. Limited circulation capacity: When the working conditions at the application site change, the circulation and adjustment capacity of this product may not meet the requirements of the working conditions, and the entire machine must be replaced, resulting in production stoppage, reduced efficiency and new machine purchase costs. Summary of the Invention

[0016] The purpose of this invention is to provide a low-shear regulating device for chemical injection wells, which solves the problems of unstable operation, poor pressure reduction effect and limited flow capacity of current low-shear regulating valves. It is installed at the wellhead of the injection well where chemical injection is required, reducing the impact of mechanical shear on the properties of the chemical during the chemical injection production process, improving the operational stability of the injection well production process, improving the pressure reduction effect and flow capacity of the low-shear regulating valve, and thus improving the production effect of the chemical injection well.

[0017] The technical solution of this invention is:

[0018] A low-shear regulating device for a pharmaceutical injection well includes a regulating valve, a regulating valve body, and a Venturi pressure reducing pipe. The Venturi pressure reducing pipe is installed inside the regulating valve body. The regulating valve body has an inlet and an outlet, wherein:

[0019] The regulating valve also includes a regulating valve core, a regulating valve seat, and a buffer valve cage. A throttling orifice plate is installed between the venturi pressure reducing pipe and the regulating valve seat. The upper rod of the regulating valve core is connected to the electric actuator. The body of the regulating valve core is installed inside the buffer valve cage, the regulating valve seat, the throttling orifice plate, and the venturi pressure reducing pipe.

[0020] The orifice plate is equipped with guide holes;

[0021] The flow booster valve is connected in parallel to one side of the regulating valve. The flow booster valve and the regulating valve are connected by a shut-off valve. When the shut-off valve is opened, the medium that enters the regulating valve through the inlet of the regulating valve can be injected into the well through the outlet of the regulating valve via the shut-off valve.

[0022] Preferably, the upper part of the regulating valve body and the buffer valve cage are provided with an inlet and an outlet of the booster valve, and the lower part of the regulating valve body is provided with an inlet of the booster valve that communicates with the central flow channel of the regulating valve; the shut-off valve is connected between the regulating valve and the booster valve through the outlet and inlet of the booster valve in the regulating valve body.

[0023] Preferably, the flow booster valve includes a flow booster valve body, a second venturi pressure reducing tube, and a flow booster valve stem. The second venturi pressure reducing tube is installed inside the flow booster valve body and its two ends are fixed by the flow booster valve cover. The upper part of the flow booster valve body and the flow booster valve cover installed therein are both provided with flow booster valve inlets, and the lower part of the flow booster valve body and the flow booster valve cover installed therein are both provided with flow booster valve outlets. The flow booster valve stem passes through the flow booster valve covers installed at both ends of the flow booster valve body and the second venturi pressure reducing tube installed inside the flow booster valve body, and is fixed to the flow booster valve cover by a fastening nut.

[0024] Preferably, the outer walls of both ends of the flow booster valve body and the outer wall of the flow booster valve cover are provided with connecting plates, and the flow booster valve body and the flow booster valve cover are connected by bolts in the connecting plates; sealing rings are also provided inside and outside the lower body of the flow booster valve cover.

[0025] Preferably, the outer diameter of the flow booster valve stem is smaller than the inner diameter of the Venturi pressure reducing pipe II, and the outer diameter of the flow booster valve stem can be reduced or increased according to the injection flow rate of the oil well.

[0026] Preferably, the length of the second venturi pressure reducing tube in the flow booster valve is greater than the length of the first venturi pressure reducing tube in the regulating valve.

[0027] Preferably, the valve core of the regulating valve consists of, from top to bottom, a connecting structure, a sealing rod, a conical rod, and a throttling rod, wherein both the sealing rod and the throttling rod are cylindrical rods; the minimum outer diameter of the conical rod is greater than the outer diameter of the sealing rod; and the outer diameter of the sealing rod is greater than the outer diameter of the throttling rod.

[0028] Preferably, the outer diameter of the throttling rod is smaller than the minimum inner diameter of the Venturi pressure reducing pipe, and the outer diameter of the throttling rod can be reduced or increased according to the injection flow rate of the injection well; the taper of the tapered rod matches the taper of the inner cavity of the regulating valve seat; a sealing element is installed between the sealing rod and the regulating valve cover; the connection structure is a connecting square, a connecting hole, or a connecting thread.

[0029] Preferably, the guide hole is disposed on the outer periphery of the central hole of the throttling orifice plate, and the guide hole is connected to the central hole of the throttling orifice plate. The two ends of the central hole of the throttling orifice plate are chamfered.

[0030] The central hole at the top of the buffer cage valve matches the outer diameter of the sealing rod in the regulating valve core, and the lower inner cavity of the buffer cage valve is larger than the maximum outer diameter of the tapered rod in the regulating valve core; the liquid inlet at the top of the regulating valve body and the central flow channel at the bottom of the regulating valve are both tapered flow channels.

[0031] Compared with the regulating valves for injecting chemicals in existing chemical injection well production processes, the significant advantages of this invention are:

[0032] This invention comprises a regulating valve and a flow booster valve. The regulating valve contains a regulating valve core and a regulating valve seat. The tapered rod in the regulating valve core has the same taper as the inner cavity of the regulating valve seat. When the regulating valve is open, the medium can form a long-distance laminar flow. The pressure of the medium is reduced by the friction between the tapered rod wall and the inner cavity of the regulating valve seat. A throttling orifice plate is installed between the regulating valve seat and the first Venturi pressure-reducing pipe, and the throttling rod in the regulating valve core can move up and down within the orifice plate. The flow rate of the medium passing through can be adjusted by raising or lowering the regulating valve core. The central hole of the throttling orifice plate fits tightly against the regulating valve core, preventing vibration of the regulating valve core. The guide holes evenly distributed around the outer periphery of the central hole of the throttling orifice plate allow the medium, after laminar flow and pressure reduction through the regulating valve core and valve seat, to re-enter the throttling rod in the regulating valve core and the first Venturi pressure-reducing pipe for further pressure reduction. The outer diameter of the throttling rod and the minimum inner diameter of the venturi pressure reducing tube form a certain variable flow channel area. The size of this area changes continuously with the constant large and small diameters of the venturi pressure reducing tube, causing the medium to flow in turbulent flow. Because the angle change of the venturi pressure reducing tube is smooth, it does not cause abrupt changes in flow velocity, so that the medium does not generate excessive shear force when flowing, thus maintaining the viscosity of the medium while reducing pressure.

[0033] Meanwhile, a flow booster valve is provided in this invention. The flow booster valve is connected in parallel to one side of the regulating valve body via a shut-off valve. The flow booster valve stem and the second Venturi pressure reducing tube in the flow booster valve reduce the pressure of the medium while maintaining the viscosity of the medium.

[0034] When the flow capacity of the regulating valve is insufficient, the flow booster valve can divert the medium to the parallel flow booster valve by opening the shut-off valve, thereby increasing the flow capacity of the device. The flow booster valve is connected to the regulating valve through the shut-off valve. The flow booster valve can be opened or closed according to the required medium flow rate on site. The flow booster valve acts as a quantitative compensation for the flow rate, while the momentum control of the medium flow rate is always achieved and ultimately precisely controlled through the regulating valve.

[0035] The flow booster valve has a simple and practical structure. After the shut-off valve is closed, the flow booster valve stem can be replaced online without stopping production, thereby increasing or decreasing the amount of flow rate compensation.

[0036] This invention can be used in the injection process of chemicals at the wellhead of injection wells, such as in the injection of polymers and in oilfield processes involving binary composite flooding, ternary composite flooding, heterogeneous flooding, gel profile control, and weak gel plugging. It is suitable for injecting mother liquors containing ultra-high concentration and ultra-high viscosity polymers, with a flow rate range of 0.2... 3 / h-2.5m 3 Adjust between / h.

[0037] Compared to existing regulating valves for injecting chemicals, this invention is installed at the wellhead of the injection well that requires chemical injection, thus achieving single-well chemical injection control in the chemical injection production process.

[0038] In summary, this invention significantly improves the operational stability of the injection well production process, ensures that the properties of the injected chemicals are not affected by mechanical shear, and significantly improves the pressure reduction effect and flow capacity of the low-shear regulating valve, thereby enhancing the development effect of the chemical injection well. It has significant practical effects and application value, and can achieve good economic benefits. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0040] Figure 1 This is a schematic diagram of the structure of the present invention.

[0041] Figure 2 yes Figure 1 A schematic diagram of the structure of the buffer valve cage.

[0042] Figure 3 yes Figure 1 Top view of the orifice plate.

[0043] Figure 4 yes Figure 1 A schematic diagram of the valve core of the regulating valve.

[0044] In the diagram: 1. Control valve body; 2. Venturi pressure reducing pipe 1; 3. Control valve core; 3. Connecting structure; 31. Sealing rod; 32. Conical rod; 33. Throttling rod; 34. Control valve seat; 4. Throttling orifice plate; 5. Guide hole; 51. Buffer cage; 6. Control valve cover; 7. Seal; 8. Electric actuator; 9. Flow booster valve body; 10. Venturi pressure reducing pipe 2; 11. Flow booster valve stem; 12. Flow booster valve cover; 13. Shut-off valve; 14. Detailed Implementation

[0045] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this invention. The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0047] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0048] See Figure 1 - Figure 4 A low-shear regulating device for a pharmaceutical injection well includes a regulating valve, a regulating valve body 1, and a Venturi pressure reducing pipe 2. The Venturi pressure reducing pipe 2 is installed inside the regulating valve body 1. The regulating valve body 1 has an inlet and an outlet, wherein:

[0049] The regulating valve also includes a regulating valve core 3, a regulating valve seat 4, and a buffer valve cage 6. A throttling orifice plate 5 is installed between the venturi pressure reducing pipe 2 and the regulating valve seat 4. The upper rod of the regulating valve core 3 is connected to the electric actuator 9. The body of the regulating valve core 3 is installed in the buffer valve cage 6, the regulating valve seat 4, the throttling orifice plate 5, and the venturi pressure reducing pipe 2.

[0050] The orifice plate 5 is provided with a guide hole 51;

[0051] A flow booster valve is connected in parallel to one side of the regulating valve. The flow booster valve and the regulating valve are connected by a shut-off valve 14. When the shut-off valve 14 is opened, the medium that enters the regulating valve through the inlet can be injected downhole through the outlet of the regulating valve via the shut-off valve 14. This invention regulates the flow rate of the regulating valve through an electric actuator 9, which has high regulation accuracy and can be quantitatively adjusted according to the needs of each well.

[0052] This invention incorporates a regulating valve core 3 and a regulating valve seat 4 within the regulating valve. When the regulating valve is open, it generates a long-distance laminar flow. The friction between the outer and inner walls of the regulating valve core 3 and the regulating valve seat 4 reduces the pressure of the medium entering the regulating valve. A throttling orifice plate 5 is installed between the regulating valve seat 4 and the Venturi pressure reducing pipe 2. The regulating valve core 3 can pass through the center of the throttling orifice plate 5 and can move up and down within it. The central hole of the throttling orifice plate 5 fits tightly against the regulating valve core 3, effectively preventing vibration of the regulating valve core 3.

[0053] The medium injected into the well enters the invention through the inlet in the regulating valve body 1. After laminar flow and pressure reduction through the regulating valve core 3 and regulating valve seat 4, the medium passes through the guide hole 51 in the orifice plate 5 and enters the space between the regulating valve core 3 and the Venturi pressure-reducing pipe 2 for further pressure reduction before being injected into the well through the outlet at the lower end of the regulating valve body 1. The lower rod of the regulating valve core 3 and the minimum inner diameter of the Venturi pressure-reducing pipe 2 form a variable flow channel area. The size of this flow channel area varies continuously between the large and small inner diameters of the Venturi pressure-reducing pipe 2, causing turbulent flow of the medium. Because the angle change of the Venturi pressure-reducing pipe 2 is smooth, it does not create abrupt changes in flow velocity, preventing excessive shear force during medium flow. Thus, while reducing pressure, the viscosity of the medium flowing through the invention is maintained.

[0054] The present invention improves the internal structure of the original regulating valve and sets up a flow booster valve on the side of the regulating valve. The regulating valve and the flow booster valve are connected by a shut-off valve 14, which can open and close the flow booster valve.

[0055] When the flow capacity of the regulating valve is insufficient, the flow booster valve can open the shut-off valve 14 to divert the medium in the regulating valve to the flow booster valve and inject it into the well through the outlet of the regulating valve, thereby improving the flow capacity of the fluid in this invention.

[0056] Because this invention connects a flow-increasing valve in parallel to one side of the regulating valve, when this invention is installed in the production process of each injection well, the injection volume can be adjusted according to the injection requirements of the installed injection well.

[0057] Based on the above embodiment one, the present invention also has the following embodiments:

[0058] The upper part of the regulating valve body 1 and the buffer valve cage 6 are provided with an inlet and an outlet of the booster valve, and the lower part of the regulating valve body 1 is provided with an inlet of the booster valve that communicates with the central flow channel of the regulating valve; the shut-off valve 14 is connected between the regulating valve and the booster valve through the outlet and inlet of the booster valve in the regulating valve body 1.

[0059] The flow booster valve comprises a flow booster valve body 10, a second Venturi pressure reducing tube 11, and a flow booster valve stem 12. The second Venturi pressure reducing tube 11 is installed inside the flow booster valve body 10 and its two ends are fixed by the flow booster valve cover 13. The upper part of the flow booster valve body 10 and the flow booster valve cover 13 installed therein both have flow booster valve inlets, and the lower part of the flow booster valve body 10 and the flow booster valve cover 13 installed therein both have flow booster valve outlets. The flow booster valve stem 12 passes through the flow booster valve cover 13 installed at both ends of the flow booster valve body 10 and the second Venturi pressure reducing tube 11 installed inside the flow booster valve body 10, and is fixed to the flow booster valve cover 13 by a fastening nut. The flow booster valve, with its second Venturi pressure reducing tube 11 and flow booster valve stem 12, can maintain the viscosity of the medium while reducing its pressure.

[0060] The outer walls at both ends of the flow booster valve body 10 and the outer wall of the flow booster valve cover 13 are provided with connecting discs, and the flow booster valve body 10 and the flow booster valve cover 13 are connected by bolts in the connecting discs; sealing rings are also provided inside and outside the lower part of the flow booster valve cover 13 to complete the sealing between the flow booster valve cover 13 and the flow booster valve body 10 and the flow booster valve stem 12. 。

[0061] The outer diameter of the flow-increasing valve stem 12 is smaller than the inner diameter of the Venturi pressure-reducing pipe 11. The outer diameter of the flow-increasing valve stem 12 can be reduced or increased according to the injection flow rate of the oil well to adapt to the injection requirements of different injection wells and increase or decrease the flow capacity of the flow-increasing valve. The flow-increasing valve can be replaced online without stopping production after the shut-off valve 14 is closed. The specific operation is as follows: close the shut-off valve 14, remove the flow-increasing valve cover 13, pull out the flow-increasing valve stem 12, and install a new flow-increasing valve stem 12 with a different outer diameter than the original one, which can increase or decrease the flow capacity of the flow-increasing valve.

[0062] The length of the Venturi pressure reducing tube 11 in the flow booster valve is greater than the length of the Venturi pressure reducing tube 2 in the regulating valve.

[0063] The regulating valve core 3 consists of a connecting structure 31, a sealing rod 32, a tapered rod 33, and a throttling rod 34 from top to bottom. Both the sealing rod 32 and the throttling rod 34 are cylindrical rods. The minimum outer diameter of the tapered rod 33 is greater than the outer diameter of the sealing rod 32. The outer diameter of the sealing rod 32 is greater than the outer diameter of the throttling rod 34.

[0064] The outer diameter of the throttle rod 34 is smaller than the minimum inner diameter of the Venturi pressure reducing pipe 2. The outer diameter of the throttle rod 34 can be reduced or increased according to the injection flow rate of the injection well to adapt to the injection requirements of different injection wells. The taper of the tapered rod 33 matches the taper of the inner cavity of the regulating valve seat 4. A sealing element 8 is installed between the sealing rod 32 and the regulating valve cover 7. ， A seal is achieved between the control valve core 3 and the control valve cover 7; the connection structure 31 is a connection block, a connection hole, or a connection thread. The connection structure 31 in the control valve core 3 allows for connection with the push rod in the electric actuator 9 via a connection clamp, a connection hole, or a connection thread.

[0065] The guide hole 51 is disposed on the outer periphery of the central hole of the throttling orifice plate 5 and is connected to the central hole of the throttling orifice plate 5. The two ends of the central hole of the throttling orifice plate 5 are chamfered to facilitate the downward flow of the medium.

[0066] The central hole at the top of the buffer cage valve 6 matches the outer diameter of the sealing rod 32 in the regulating valve core 3, and the lower inner cavity of the buffer cage valve 6 is larger than the maximum outer diameter of the tapered rod 33 in the regulating valve core 3; the liquid inlet at the top of the regulating valve body 1 and the central flow channel at the bottom of the regulating valve are both tapered flow channels.

[0067] This invention achieves both high control precision and low shear performance of the regulating valve, while significantly improving its flow control range, thus ensuring the stability and sustainability of crude oil extraction and production.

[0068] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A low-shear regulating device for a pharmaceutical injection well, comprising a regulating valve, wherein the regulating valve is provided with a regulating valve body (1) and a Venturi pressure reducing pipe (2), the Venturi pressure reducing pipe (2) being installed inside the regulating valve body (1), and the regulating valve body (1) being provided with an inlet and an outlet, characterized in that: The regulating valve is also equipped with a regulating valve core (3), a regulating valve seat (4) and a buffer valve cage (6). A throttling orifice plate (5) is installed between the venturi pressure reducing pipe (2) and the regulating valve seat (4). The upper rod of the regulating valve core (3) is connected to the electric actuator (9). The body of the regulating valve core (3) is installed in the buffer valve cage (6), the regulating valve seat (4), the throttling orifice plate (5) and the venturi pressure reducing pipe (2). The orifice plate (5) is provided with a guide hole (51); the flow booster valve is connected in parallel to one side of the regulating valve, and the flow booster valve and the regulating valve are connected by a shut-off valve (14). When the shut-off valve (14) is opened, the medium that enters the regulating valve through the inlet of the regulating valve can be injected into the well through the outlet of the regulating valve via the shut-off valve (14); the upper part of the regulating valve body (1) and the buffer valve cage (6) are provided with an inlet and a flow booster valve outlet, and the lower part of the regulating valve body (1) is provided with a flow booster valve inlet that is connected to the central flow channel of the regulating valve; the shut-off valve (14) is connected between the regulating valve and the flow booster valve through the flow booster valve outlet and the flow booster valve inlet in the regulating valve body (1); The flow booster valve is provided with a flow booster valve body (10), a second venturi pressure reducing tube (11), and a flow booster valve stem (12). The second venturi pressure reducing tube (11) is installed inside the flow booster valve body (10) and its two ends are fixed by the flow booster valve cover (13). The upper part of the flow booster valve body (10) and the flow booster valve cover (13) installed therein are both provided with flow booster valve inlets. The lower part of the flow booster valve body (10) and the flow booster valve cover (13) installed therein are also provided with flow booster valve inlets. Each part is equipped with a flow booster valve outlet; the flow booster valve stem (12) passes through the flow booster valve cover (13) installed at both ends of the flow booster valve body (10) and the venturi pressure reducing tube II (11) installed inside the flow booster valve body (10), and is fixed to the flow booster valve cover (13) by a fastening nut; the regulating valve core (3) consists of a connecting structure (31), a sealing rod (32), a conical rod (33), and a throttling rod (34) from top to bottom. Both the sealing rod (32) and the throttling rod (34) are cylindrical rods; the minimum outer diameter of the tapered rod (33) is greater than the outer diameter of the sealing rod (32); the outer diameter of the sealing rod (32) is greater than the outer diameter of the throttling rod (34); the outer diameter of the throttling rod (34) is less than the minimum inner diameter of the Venturi pressure reducing pipe (2), and the outer diameter of the throttling rod (34) can be reduced or increased according to the injection flow rate of the injection well; the taper of the tapered rod (33) matches the taper of the inner cavity of the regulating valve seat (4); the guide hole (51) is set on the outer periphery of the center hole of the throttling orifice plate (5), and the guide hole (51) is connected to the center hole of the throttling orifice plate (5); the center hole at the top of the buffer valve cage (6) matches the outer diameter of the sealing rod (32) in the regulating valve core (3), and the lower inner cavity of the buffer valve cage (6) is greater than the maximum outer diameter of the tapered rod (33) in the regulating valve core (3).

2. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, The outer walls of both ends of the flow booster valve body (10) and the outer wall of the flow booster valve cover (13) are provided with connecting plates. The flow booster valve body (10) and the flow booster valve cover (13) are connected by bolts in the connecting plates. Sealing rings are also provided inside and outside the lower part of the body of the flow booster valve cover (13).

3. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, The outer diameter of the flow booster valve stem (12) is smaller than the inner diameter of the Venturi pressure reducing pipe (11), and the outer diameter of the flow booster valve stem (12) can be reduced or increased according to the size of the injection flow rate of the oil well.

4. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, The length of the second Venturi pressure reducing tube (11) in the flow booster valve is greater than the length of the first Venturi pressure reducing tube (2) in the regulating valve.

5. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, A sealing element (8) is installed between the sealing rod (32) and the valve cover (7) of the regulating valve; the connecting structure (31) is a connecting square, a connecting hole or a connecting thread.

6. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, The center hole of the throttling orifice plate (5) has chamfers at both ends.

7. The low-shear regulating device for a pharmaceutical injection well as described in claim 1, characterized in that, The liquid inlet at the top of the regulating valve body (1) and the central flow channel at the bottom of the regulating valve are both tapered flow channels.

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