CN204041451U - A water injection screw pump protection device for the same well injection and production system - Google Patents

Abstract

The utility model discloses a water injection screw pump protection device for annotating with well and producing system belongs to oil field development oil recovery engineering field. The protection device at least comprises: the device comprises a protector component, a balancer component, a coupling component, a flow guide shell, an upper sealing seat, a lower sealing seat, a shell locking nut, a limiting sleeve, an inner cavity bracket and an anti-falling plate; the protector assembly, the balancer assembly and the coupler assembly are sequentially arranged in the diversion shell, a liquid passing channel is formed between the protector assembly, the balancer assembly and the diversion shell, the lower end of the balancer assembly is connected with the upper end of the coupler assembly, and the upper end of the balancer assembly is connected with the lower end of the protector assembly. The eccentric force generated when the screw pump works is eliminated through the coupling assembly, the centering effect is achieved through the balancer assembly, and the radial force generated by the eccentric motion of the screw pump is further eliminated; the adverse effect of axial reaction force generated when the screw pump operates on a system is eliminated through the protector component; the service life of the injection and production system in the same well is prolonged.

Description

A water injection screw pump protection device for the same well injection and production system

technical field

The utility model relates to the field of oil field development and oil production engineering, in particular to a water injection screw pump protection device used in the injection and production system of the same well.

Background technique

The same well injection and production refers to a method of oilfield water injection using formation water reinjection, which is suitable for the exploitation of oil reservoir resources in old oilfields, retail and small blocks.

The screw pump is a rotary pump that uses the mutual meshing of screws to suck and discharge liquid. When the input shaft drives the rotor around the stator for planetary rotation through the universal joint, the stator and the rotor are continuously meshed to form a sealed cavity. Pay delivery to the extrusion end.

As the oilfield enters the late stage of high water cut, the liquid-oil ratio rises, the system back pressure is high, and a large amount of produced water undergoes long-distance circulation, resulting in increased energy consumption of the gathering and transportation system. The same-well injection-production system can separate oil and water from crude oil with high water content downhole, and re-inject the water separated by the separation system directly into the injection layer, so that the water injection and oil production processes in the production wellbore can be carried out simultaneously. The key technology of the system is how to eliminate the impact on the system caused by the eccentric movement and axial reaction force generated during the operation of the injection screw pump.

In the process of realizing the utility model, the inventor finds that the prior art has at least the following problems:

The existing electric submersible pump protector is generally composed of an upper joint assembly, an upper and lower check valve assembly, an upper and lower capsule, a breathing catheter assembly, a shaft, a settling chamber, etc., but this protector cannot be applied to a screw pump system, and It can only bear the downward pressure load, and cannot bear the load of the upward force generated when the water injection screw pump in the same well injection-production system works.

Contents of the invention

In order to solve the problems of the prior art, the embodiment of the utility model provides a water injection screw pump protection device for the injection and production system of the same well. Eliminate the adverse effects on the system caused by the eccentric movement and upward reaction force generated by the screw pump during operation, and effectively prolong the service life of the injection-production system in the same well. Described technical scheme is as follows:

A water injection screw pump protection device for the same well injection and production system, the protection device at least includes: a protector assembly, a balancer assembly, a coupling assembly, a diversion casing, an upper sealing seat, a lower sealing seat, and a casing locking Female, spacer sleeve, inner cavity bracket, anti-falling plate; the protector assembly, balancer assembly, and coupling assembly are sequentially arranged in the diversion shell, and a liquid passage is formed between the diversion shell, and the The lower end of the balancer assembly is connected with the upper end of the coupling assembly, and the upper end of the balancer assembly is connected with the lower end of the protector assembly.

The diversion shell is provided with a limit sleeve, an inner cavity bracket and an anti-fall plate, which are fixedly connected by the shell locking nut; one end of the diversion shell is connected to the upper sealing seat, and the other end is connected to the lower sealing seat.

The protector assembly at least includes: lower connecting seat, bearing retaining ring, capsule lower seat, shell, capsule sleeve, transmission shaft, capsule upper seat, middle joint, bearing pressure plate, upper joint, shaft collar, mechanical seal pin, cylinder Roller bearings, circlips, oil drain plugs, thrust cylindrical roller bearings, locking plates, capsules, capsule clips.

A capsule sleeve is installed on the transmission shaft, a capsule lower seat and a capsule upper seat are installed on the capsule sleeve, the capsule is installed through the capsule clip, the capsule is arranged in the shell, and one end of the shell is connected to the middle joint and the upper joint, the other end of which is connected to the lower connecting seat; cylindrical roller bearings are installed in the upper joint, thrust cylindrical roller bearings and bearing pressure plates are installed in the middle joint; cylindrical roller bearings, bearing stoppers are installed in the lower connecting seat The ring is provided with an oil drain plug, and the lower connecting seat and the transmission shaft are sealed by a mechanical seal pin. Here, a circlip is arranged on the sealing shaft section, and one end of the transmission shaft is connected to a shaft collar.

The balancer assembly at least includes: a spline sleeve, a lower connecting seat, a cylindrical roller thrust bearing, a bearing installation sleeve, an annular spring, a single row cylindrical roller bearing, a lower shaft, a middle and upper joint, an overflow valve assembly, a middle and a lower Joint, shell, spacer sleeve, upper shaft, upper connecting seat, oil drain plug, circlip, upper transport cap, locking plate, mechanical seal pin, gasket.

The upper shaft is arranged in the casing, and a spacer sleeve is arranged on the upper shaft. One end of the casing is connected to the middle and lower joints, and the other end is connected to the upper connecting seat. The upper connecting seat is provided with an oil drain plug 2.15, and the middle and lower joints are connected to The middle and upper joints, the middle and upper joints are connected to the lower connection seat, and the lower connection seat is provided with a spline sleeve; the middle and lower joints are provided with a relief valve assembly, and the lower shaft in the middle and upper joints is It is provided with a cylindrical roller thrust bearing, a bearing installation sleeve, a ring spring, and a single row cylindrical roller bearing.

The upper connecting seat and the upper shaft are sealed by a mechanical seal pin, here a circlip is arranged on the sealing shaft section, and an upper transportation cap is arranged at one end of the upper connecting seat.

The coupling assembly at least includes: a lower connection seat, a casing, a universal input shaft, a spherical universal joint, a universal joint shaft, an output shaft, a non-return retaining ring, a non-return gear sleeve, a suction port, a locking plate, a sealing Capsule, capsule clamp, spline set, molybdenum disulfide grease, shaft collar.

The cardan shaft is arranged in the housing, one end of the housing is connected to the lower connection seat, and the other end is connected to the suction port; one end of the cardan shaft is connected to the universal input shaft through a spherical universal joint, and the other end is connected to the universal input shaft through a spherical universal joint. The output shaft is connected; the universal input shaft is connected with the sealing capsule through the capsule clamp to form a sealed cavity, and molybdenum disulfide grease is injected into the cavity.

The output shaft is provided with a non-return retaining ring and a non-return gear sleeve, and the output shaft is connected to the sealed capsule through a capsule clip to form a cavity, and molybdenum disulfide grease is injected into the cavity; one end of the universal input shaft is connected to a spline sleeve group, one end of the output shaft is connected to the shaft collar.

The beneficial effects brought by the technical solution provided by the embodiment of the utility model are:

1. The eccentric force generated by the screw pump can be eliminated through the coupling assembly, and the sealing structure of the coupling assembly can isolate the lubricating medium of the coupling assembly from the original well fluid, which can adapt to the harsh environment of the downhole and ensure The service life of the coupling assembly;

2. Use the balancer assembly to play a righting role, further eliminating the radial force generated by the eccentric movement of the screw pump;

3. The adverse effect on the system caused by the axial reaction force generated during the operation of the screw pump can be eliminated through the protector assembly; the breathing capsule provided with the protector assembly can provide long-term lubrication for the thrust bearing, effectively ensuring the use of the bearing life.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description are only some implementations of the present invention. For example, those of ordinary skill in the art can also obtain other drawings based on these drawings on the premise of not paying creative efforts.

Fig. 1 is a schematic diagram of the structure of the water injection screw pump protection device for the same well injection and production system provided by the embodiment of the utility model;

Fig. 2 is a schematic structural diagram of the protector assembly in Fig. 1 provided by the embodiment of the present invention;

Fig. 3 is a schematic structural diagram of the balancer assembly in Fig. 1 provided by the embodiment of the present invention;

Fig. 4 is a schematic structural diagram of the coupling assembly in Fig. 1 provided by the embodiment of the present invention;

Fig. 5 is a schematic diagram of the use of the water injection screw pump protection device for the same well injection and production system provided by the embodiment of the utility model.

The meanings of the symbols in Figure 1 are as follows:

1 Protector assembly, 2 Balancer assembly, 3 Coupling assembly, 4 Diversion shell, 5 Upper sealing seat, 6 Lower sealing seat, 7 Housing locking nut, 8 Limiting sleeve, 9 Inner cavity bracket, 10 Anti-fall plate.

The meanings of the symbols in Figure 2 are as follows:

1.1 Lower connecting seat, 1.2 Bearing retaining ring, 1.3 Capsule lower seat, 1.4 Shell, 1.5 Capsule casing, 1.6 Transmission shaft, 1.7 Capsule upper seat, 1.8 Middle joint, 1.9 Bearing pressure plate, 1.10 Upper joint, 1.11 Shaft collar, 1.12 Mechanical Seal pin, 1.13 cylindrical roller bearing, 1.14 circlip, 1.15 oil drain plug, 1.16 thrust cylindrical roller bearing, 1.17 locking plate, 1.18 capsule, 1.19 capsule clip.

The meanings of the symbols in Figure 3 are as follows:

2.1 Spline sleeve, 2.2 Lower connection seat, 2.3 Cylindrical roller thrust bearing, 2.4 Bearing installation sleeve, 2.5 Ring spring, 2.6 Single row cylindrical roller bearing, 2.7 Lower shaft, 2.8 Middle upper joint, 2.9 Relief valve assembly, 2.10 Middle and lower joints, 2.11 shell, 2.12 spacer sleeve, 2.13 upper shaft, 2.14 upper connecting seat, 2.15 oil drain plug, 2.16 circlip, 2.17 upper transportation cap, 2.18 locking plate, 2.19 mechanical seal pin, 2.20 gasket.

The meanings of the symbols in Figure 4 are as follows:

3.1 Lower connecting seat, 3.2 Shell, 3.3 Universal input shaft, 3.4 Spherical universal joint, 3.5 Universal shaft, 3.6 Output shaft, 3.7 Non-return retaining ring, 3.8 Non-return gear sleeve, 3.9 Suction port, 3.10 Locking plate, 3.11 Sealing capsule, 3.12 Capsule clamp, 3.13 Spline set, 3.14 Molybdenum disulfide grease, 3.15 Shaft collar.

The meanings of the symbols in Figure 5 are as follows:

1 Protector assembly, 2 Balancer assembly, 3 Coupling assembly, 11 Oil pipe, 12 Screw pump, 13 Fluid passage;

The direction of the upward arrow is the direction of the reaction force, and the direction of the downward arrow is the direction of the liquid flow.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present utility model clearer, the implementation of the present utility model will be further described in detail below in conjunction with the accompanying drawings.

Referring to Fig. 1, the embodiment of the utility model provides a water injection screw pump protection device for the same well injection and production system, the protection device at least includes: a protector assembly 1, a balancer assembly 2, and a coupling assembly 3 , diversion shell 4, upper seal seat 5, lower seal seat 6, shell lock nut 7, limit sleeve 8, inner cavity bracket 9, anti-fall plate 10 and other components; specifically, the protector assembly 1, After the balancer assembly 2 and the coupling assembly 3 are assembled, they are sequentially arranged in the guide housing 4, that is, the lower end of the balancer assembly 2 is connected to the upper end of the shaft coupling assembly 3, and the upper end of the balancer assembly 2 is connected to the protector assembly 1. The lower ends are connected; the diversion shell 4 is provided with a number of limit sleeves 8, inner cavity brackets 9 and anti-fall plates 10, which are fixedly connected by the shell locking nut 7; one end of the diversion shell 4 is connected to the upper seal Seat 5, the other end is connected to the lower sealing seat 6.

Referring to Fig. 2, the protector assembly 1 at least includes: a lower connecting seat 1.1, a bearing retaining ring 1.2, a capsule lower seat 1.3, a casing 1.4, a capsule sleeve 1.5, a transmission shaft 1.6, a capsule upper seat 1.7, a middle joint 1.8, Bearing pressure plate 1.9, upper joint 1.10, shaft coupling 1.11, mechanical seal pin 1.12, cylindrical roller bearing 1.13, circlip 1.14, oil drain plug 1.15, thrust cylindrical roller bearing 1.16, locking plate 1.17, capsule 1.18, capsule clamp 1.19 and other parts.

Specifically, a capsule sleeve 1.5 is installed on the drive shaft 1.6, a capsule lower seat 1.3 and a capsule upper seat 1.7 are installed on the capsule sleeve 1.5, and a capsule 1.18 is installed through a capsule clamp 1.19. MPa pressure, no leakage is allowed within five minutes, the capsule 1.18 is set in the shell 1.4, one end of the shell 1.4 is connected to the middle joint 1.8 and the upper joint 1.10 through the locking plate 1.17, and the other end of the shell 1.4 is connected to the lower connecting seat through the locking plate 1.17 1.1; a cylindrical roller bearing 1.13 is installed in the upper joint 1.10, a thrust cylindrical roller bearing 1.16 and a bearing pressure plate 1.9 are installed in the middle joint 1.8, and the large outer diameter cover of the thrust cylindrical roller bearing 1.16 is tightly mounted on the right The small outer diameter cover is placed on the left side, and the thrust cylindrical roller bearing 1.16 is used to bear the upward force generated when the screw pump rotor moves, that is, the axial force, and eliminate the eccentric movement of the screw pump and the reaction force during operation Adverse effects on the system; the capsule 1.18 is provided with a lubricant, which provides lubrication for the thrust cylindrical roller bearing 1.16 through the drain hole, ensuring the service life of the bearing.

The lower connecting seat 1.11 is installed with a cylindrical roller bearing 1.13, a bearing retaining ring 1.2, and an oil drain plug 1.15. The lower connecting seat 1.1 and the transmission shaft 1.6 are sealed with a mechanical seal pin 1.12. There are two snap springs 1.14, one is left-handed and the other is right-handed; one end of the transmission shaft 1.6 is connected with a shaft collar 1.11, and all threads are coated with sealant.

Referring to Fig. 3, the balancer assembly 2 at least includes: a spline sleeve 2.1, a lower connecting seat 2.2, a cylindrical roller thrust bearing 2.3, a bearing mounting sleeve 2.4, an annular spring 2.5, a single row cylindrical roller bearing 2.6, and a lower shaft 2.7, middle and upper joint 2.8, overflow valve assembly 2.9, middle and lower joint 2.10, housing 2.11, spacer sleeve 2.12, upper shaft 2.13, upper connecting seat 2.14, oil drain plug 2.15, retaining spring 2.16, upper transportation cap 2.17, Locking plate 2.18, mechanical seal pin 2.19, gasket 2.20 and other parts.

Specifically, the upper shaft 2.13 is set in the housing 2.11, and the upper shaft 2.13 is provided with a spacer sleeve 2.12. One end of the housing 2.11 is connected to the middle and lower joints 2.10 through the locking plate 2.18, and the other end is connected to the upper and lower joints through the locking plate 2.18. Seat 2.14, the upper connecting seat 2.14 is provided with an oil drain plug 2.15, the middle and lower joint 2.10 is connected with the middle and upper joint 2.8, the middle and upper joint 2.8 is connected with the lower connecting seat 2.2 through the locking plate 2.18, and the lower connecting seat 2.2 is provided with a spline Set 2.1; the middle and lower joint 2.10 is provided with a relief valve assembly 2.9, and the lower shaft 2.7 in the middle and upper joint 2.8 is provided with a cylindrical roller thrust bearing 2.3, a bearing installation sleeve 2.4, an annular spring 2.5, and a single row Cylindrical roller bearing 2.6, the bearing plays a righting role to eliminate the radial force generated by the eccentric movement of the screw pump; the upper shaft 2.13 and the adjacent part of the lower shaft 2.7 are butted and adjusted with gasket 2.20, and there should be no gap.

The upper connecting seat 2.14 and the upper shaft 2.13 are sealed by a mechanical seal pin 2.19. There are two circlips 2.16 on the sealing shaft section, one of which is left-handed and the other is right-handed. One end of the seat 2.14 is provided with an upper transportation cap 2.17; after assembly, use dry air or fluorine gas to pressurize the mechanical seal to 0.035MPa, and pressurize the overall seal to 0.05MPa. There will be no leakage within five minutes, and the overflow valve will be at 0.02-0.035MPa Open; the shell 2.11 is coated with sealant at the threaded joints of the middle and lower joints 2.10 and the upper connecting seat 2.14.

Referring to Fig. 4, the coupling assembly 3 at least includes: a lower connection seat 3.1, a housing 3.2, a universal input shaft 3.3, a spherical universal joint 3.4, a universal shaft 3.5, an output shaft 3.6, and a non-return retaining ring 3.7 , Non-return gear sleeve 3.8, suction port 3.9, locking plate 3.10, sealing capsule 3.11, capsule clip 3.12, spline set 3.13, molybdenum disulfide grease 3.14, shaft coupling 3.15 and other components.

Specifically, the cardan shaft 3.5 is arranged in the casing 3.2, one end of the casing 3.2 is connected to the lower connecting seat 3.1 through the locking plate 3.10, and the other end is connected to the suction port 3.9 through the locking plate 3.10; one end of the cardan shaft 3.5 passes through The spherical universal joint 3.4 is connected to the universal input shaft 3.3, and the other end is connected to the output shaft 3.6 through the spherical universal joint 3.4; the universal input shaft 3.3 is connected to the sealing capsule 3.11 through the capsule clip 3.12 to form a sealed cavity, and the cavity is filled with Molybdenum disulfide grease 3.14 and sealing capsule 3.11 isolate the lubricating medium of the coupling assembly 3 from the original well fluid, which can adapt to the harsh environment in the well and ensure the service life. The shell 3.2 is used to restrict the movement angle of the coupling assembly 3 to avoid Excessive angles of movement are damaged.

The output shaft 3.6 is provided with a non-return retaining ring 3.7 and a non-return gear sleeve 3.8. The output shaft 3.6 is connected to the sealing capsule 3.11 through the capsule clip 3.12 to form a cavity, and the cavity is filled with molybdenum disulfide grease 3.14; the universal One end of the input shaft 3.3 is connected to a spline sleeve set 3.13, and one end of the output shaft 3.6 is connected to a shaft collar 3.15. Before assembly, the sealed capsule 3.11 needs to be pressed at 0.05MPa, and no leakage is allowed within five minutes. The coupling assembly 3 is mainly used to adjust the radial force generated by the eccentric movement of the screw pump.

Referring to Fig. 5, the usage method of the present utility model: the protector assembly 1, the balancer assembly 2, and the coupling assembly 3 are assembled into a protection device, and a liquid passage 13 is formed between the diversion shell 4, which is a screw pump 12 provides a liquid passage; when installing, screw the shaft collar at the upper end of the protector assembly 1 with the oil pipe 11, connect the lower end of the casing of the coupling assembly 3 with the outer tube of the stator of the screw pump 12 through threads, and connect the lower end of the coupling assembly 3 The shaft collar and the upper joint of the rotor of the screw pump 12 are threadedly connected; the original well fluid enters the liquid passage 13 through the oil pipe 11, flows through the protector assembly 1, the balancer assembly 2, and the coupling assembly 3 in sequence to the inlet of the injection pump, and passes through the Inject the injection layer after the injection pump is pressurized. The direction of the upward arrow in the figure is the direction of the reaction force, and the direction of the downward arrow is the direction of the liquid flow.

Tests have proved that the embodiment of the utility model can reduce the water content of high water-cut oil wells by 5-7%, and reduce the amount of produced fluid by more than 50% without losing crude oil, effectively reducing the long-distance circulation of a large amount of produced water. The energy consumption of the gathering and transportation system can effectively prolong the service life of the same well injection-production system. Suitable for high water cut oil fields.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (10)

1. the water filling screw pump protective gear for single-well injection-production system, it is characterized in that, this protective gear at least comprises: protector assembly, balace weight assembly, coupling assembly, water conservancy diversion shell, top seal seat, lower seal seat, shell locking mother, stop collar, inner chamber support, anti-a kind of rhyme scheme in Chinese operas serving as the prelude to a complete score for voices; Described protector assembly, balace weight assembly, coupling assembly are arranged in water conservancy diversion shell in turn; and formed liquid passage between water conservancy diversion shell; described balace weight assembly lower end and coupling assembly upper end are connected, and described balace weight assembly upper end and protector assembly lower end are connected.

2. the water filling screw pump protective gear for single-well injection-production system according to claim 1, is characterized in that, be provided with stop collar, inner chamber support and anti-a kind of rhyme scheme in Chinese operas serving as the prelude to a complete score for voices in described water conservancy diversion shell, is connected firmly by shell locking mother; Described water conservancy diversion shell one end connects top seal seat, and the other end connects lower seal seat.

3. the water filling screw pump protective gear for single-well injection-production system according to claim 1; it is characterized in that, described protector assembly at least comprises: seat, shell, capsule sleeve pipe, transmission shaft, the capsule seat of honour, middle joint, bearing plate, upper connection, the hoop that is coupling, mechanical seal pin, roller bearing, jump ring, oil drain plug, cylindrical roller thrust bearing, latch, capsule, capsule clamp under lower connecting base, end ring, capsule.

4. the water filling screw pump protective gear for single-well injection-production system according to claim 3, it is characterized in that, described transmission shaft is provided with capsule sleeve pipe, described capsule sleeve pipe is provided with seat and the capsule seat of honour under capsule, by capsule clamp, capsule is installed, described capsule is arranged in the enclosure, and described shell one end connects middle joint and upper connection, and the other end connects lower connecting base; In described upper connection, roller bearing is installed, cylindrical roller thrust bearing, bearing plate are installed in middle joint; Be provided with roller bearing, end ring in described lower connecting base, be provided with oil drain plug, described lower connecting base and transmission shaft are sealed by mechanical seal pin, seal on shaft part herein and are provided with jump ring, one end joining shaft box cupling of described transmission shaft.

5. the water filling screw pump protective gear for single-well injection-production system according to claim 1; it is characterized in that, described balace weight assembly at least comprises: spline housing, lower connecting base, roller thrust bearing, bearing mounting sleeve, annular spring, single row roller bearing, lower shaft, middle upper connection, relief valve assembly, middle lower contact, housing, separation sleeve, upper axle, upper connecting base, oil drain plug, jump ring, upper transport cap, latch, mechanical seal pin, pad.

6. the water filling screw pump protective gear for single-well injection-production system according to claim 5, it is characterized in that, described upper axle is arranged in housing, upper axle is provided with separation sleeve, lower contact during shell one end connects, the other end connects upper connecting base, described upper connecting base is provided with oil drain plug 2.15, upper connection during described middle lower contact connects, described middle upper connection connects lower connecting base, is provided with spline housing in described lower connecting base; Described middle lower contact is provided with relief valve assembly, the lower shaft in described middle upper connection is provided with roller thrust bearing, bearing mounting sleeve, annular spring, single row roller bearing.

7. the water filling screw pump protective gear for single-well injection-production system according to claim 6; it is characterized in that; described upper connecting base and upper axle are sealed by mechanical seal pin, and seal on shaft part herein and be provided with jump ring, one end of described upper connecting base is provided with transport cap.

8. the water filling screw pump protective gear for single-well injection-production system according to claim 1; it is characterized in that, described coupling assembly at least comprises: lower connecting base, shell, universal input shaft, universal ball joint, cardan shaft, output shaft, non-return back-up ring, non-return shelves cover, suction port, latch, sealing capsule, capsule clamp, spline housing group, molybdenum disulphide grease, be coupling hoop.

9. the water filling screw pump protective gear for single-well injection-production system according to claim 8, is characterized in that, described cardan shaft is arranged in the enclosure, and described shell one end connects lower connecting base, and the other end connects suction port; One end of described cardan shaft connects universal input shaft by universal ball joint, and the other end connects output shaft by universal ball joint; Described universal input shaft connects sealing capsule by capsule clamp and forms seal chamber, in cavity, be marked with molybdenum disulphide grease.

10. the water filling screw pump protective gear for single-well injection-production system according to claim 9, it is characterized in that, described output shaft is provided with non-return back-up ring, non-return shelves cover, output shaft connects sealing capsule by capsule clamp and forms cavity, is marked with molybdenum disulphide grease in cavity; Described universal input shaft one end connects spline housing group, one end joining shaft box cupling of described output shaft.