Hydraulic backwashing underground circulating device for immovable string of layered water injection well

Abstract

The utility model relates to the technical field of oil extraction of oil and gas fields, and discloses a separate injection well immovable string hydraulic backwashing underground circulating device which comprises an upper connector, a fastening pin is installed at the bottom of the upper connector, one end of the fastening pin is fixedly connected with a piston cylinder, a first sealing ring is arranged in the piston cylinder, and a second sealing ring is arranged in the piston cylinder. And a second sealing ring is mounted in the upper joint. According to the immovable tubular column hydraulic backwashing underground circulating device for the layered water injection well, the water injection process is changed on the ground, namely, through the ground process, a positive water injection opening is changed into a water return outlet, an oil sleeve annulus is changed into an injection opening, or well washing equipment and a cement truck on a platform are directly connected into a sleeve gate of the oil sleeve annulus, water injection is stopped, and water injection is completed. When the casing pressure is larger than the oil pressure by more than 0.5 MPa, backwashing operation is achieved, normal water injection production can be recovered by replacing a water injection process at a wellhead after thorough backwashing well construction, construction is simple and reliable, cost is low, and no extra equipment is needed.

Description

TECHNICAL FIELD

[0001] The utility model relates to oil and gas field oil production technical field, concretely is the downhole circulating device of hydraulic backwashing of layered water injection well immobile pipe column. BACKGROUND

[0002] At present, the layered water injection pipe column used in each oil field all has the problems of backwashing difficulty or incapable of well washing, in the water injection process, with the continuous increase of injection time, the impurities in water gradually block the channel, leading to water injection difficulty or even pump stoppage and production stoppage, if cleaning and washing are carried out, the whole or partial well pipe column needs to be pulled out, large equipment needs to be used and several days of time is needed, the cost is less than several hundred thousand yuan, more than one million yuan, therefore, we need the downhole circulating device of hydraulic backwashing of layered water injection well immobile pipe column. UTILITY MODEL CONTENTS

[0003] The utility model discloses a downhole circulating device of hydraulic backwashing of layered water injection well immobile pipe column, to solve the problem of backwashing difficulty or incapable of well washing of the layered water injection pipe column used in each oil field in the above background art, in the water injection process, with the continuous increase of injection time, the impurities in water gradually block the channel, leading to water injection difficulty or even pump stoppage and production stoppage, if cleaning and washing are carried out, the whole or partial well pipe column needs to be pulled out, large equipment needs to be used and several days of time is needed.

[0004] To achieve the above object, the utility model provides the following technical scheme:

[0005] The downhole circulating device of hydraulic backwashing of layered water injection well immobile pipe column, including upper joint, the bottom of upper joint is installed with fastening pin, and one end of fastening pin is fixedly connected with piston cylinder, the inside of piston cylinder is provided with first sealing washer, the inside of upper joint is installed with second sealing washer, the top of piston cylinder is provided with sealing backwash valve, and the top of sealing backwash valve is installed with third sealing washer, one side of sealing backwash valve is provided with sealing valve seat, and the top of sealing valve seat is installed with central tube, one side of sealing valve seat is provided with outer tube, and the bottom of outer tube is installed with inclined surface spacer ring, one side of inclined surface spacer ring is provided with sealing assembly, and one side of sealing assembly is installed with installation spacer ring, one side of installation spacer ring is provided with fourth sealing washer, the bottom of outer tube is installed with limiting mandrel, the bottom of outer tube is provided with fifth sealing washer, and the outside of fifth sealing washer is installed with guide shoe, one end of central tube is provided with lower joint, one side of sealing backwash valve is installed with adjusting ring, and one side of adjusting ring is provided with spring.

[0006] Preferably, the upper joint and the piston cylinder form a fixed structure through the fastening pins, and the number of fastening pins is multiple.

[0007] Preferably, the piston cylinder and the adjusting ring form an elastic structure through the spring.

[0008] Preferably, the piston cylinder is fixed with the outer cylinder through a sealing valve seat, and the sealing valve seat is arranged between the piston cylinder and the outer cylinder.

[0009] Preferably, the center pipe is fixed with the lower joint through a fastening pin, and the second sealing ring is arranged between the center pipe and the lower joint.

[0010] Preferably, the inclined surface spacer ring is fixed with the mounting spacer ring through a sealing assembly, and the sealing assembly is arranged between the inclined surface spacer ring and the mounting spacer ring.

[0011] Preferably, the outer cylinder is fixed with the guide shoe through a fastening pin, and the fifth sealing ring is arranged between the outer cylinder and the guide shoe.

[0012] Compared with the prior art, the beneficial effects of the layered water injection well are as follows:

[0013] The design changes the water injection flow process on the ground, that is, the positive water injection port is changed into a backwater outlet, the oil sleeve annulus is changed into an injection inlet, or the well casing gate of the oil sleeve annulus is directly connected to the well casing gate of the oil sleeve annulus by using the well cleaning equipment and the cement truck on the platform, the water injection is stopped, when the casing pressure is greater than the oil pressure by more than 0.5 MPa, the backwashing operation is realized, after the well is thoroughly backwashed, the water injection flow process is replaced at the wellhead, and normal water injection production can be restored. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is a schematic diagram of a vertical cross-sectional structure of the utility model.

[0015] In the drawing: 1, upper joint; 2, fastening pin; 3, piston cylinder; 4, first sealing ring; 5, second sealing ring; 6, third sealing ring; 7, sealing backwashing valve; 8, sealing valve seat; 9, center pipe; 10, outer cylinder; 11, inclined surface spacer ring; 12, sealing assembly; 13, mounting spacer ring; 14, fourth sealing ring; 15, limiting mandrel; 16, fifth sealing ring; 17, guide shoe; 18, lower joint; 19, spring; 20, adjusting ring. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0017] Please refer to Figure 1The utility model provides a layered water injection well immobile string hydraulic backwashing well down circulating device, including upper joint 1, the bottom of upper joint 1 is equipped with fastening pin 2, and one end of fastening pin 2 is fixedly connected with piston cylinder 3, the inside of piston cylinder 3 is provided with first sealing ring 4, the inside of upper joint 1 is equipped with second sealing ring 5, the top of piston cylinder 3 is provided with sealing backwash valve 7, and the top of sealing backwash valve 7 is equipped with third sealing ring 6, one side of sealing backwash valve 7 is provided with sealing valve seat 8, and the top of sealing valve seat 8 is equipped with central tube 9, one side of sealing valve seat 8 is provided with outer tube 10, and the bottom of outer tube 10 is equipped with inclined surface spacer ring 11, one side of inclined surface spacer ring 11 is provided with sealing assembly 12, and one side of sealing assembly 12 is equipped with installation spacer ring 13, one side of installation spacer ring 13 is provided with fourth sealing ring 14, the bottom of outer tube 10 is equipped with limiting mandrel 15, the bottom of outer tube 10 is provided with fifth sealing ring 16, and the outside of fifth sealing ring 16 is equipped with guide shoe 17, one end of central tube 9 is provided with lower joint 18, one side of sealing backwash valve 7 is equipped with adjusting ring 20, and one side of adjusting ring 20 is provided with spring 19.

[0018] Through the above technical scheme, the water injection flow process is changed on the ground, that is, the positive water injection port is changed into a backwater outlet, the oil sleeve annulus is changed into an injection inlet, or the casing gate of the oil sleeve annulus is directly connected to the oil sleeve annulus by using the well cleaning equipment and the cement truck on the platform to stop water injection. When the casing pressure is greater than the oil pressure by more than 0.5 MPa, backwashing operation is realized, and after thorough backwashing well construction, the wellhead is changed to the water injection flow process to restore normal water injection production. The construction is simple and reliable, the cost is low, and no additional equipment is needed.

[0019] Specifically, the upper joint 1 and the piston cylinder 3 form a fixed structure through the fastening pins 2, and the number of fastening pins 2 is multiple.

[0020] Through the above technical scheme, the upper joint 1 and the piston cylinder 3 are fixed and limited by the fastening pins 2, and are sealed by the first sealing ring 4, achieving the effect of sealed connection.

[0021] Specifically, the piston cylinder 3 and the adjusting ring 20 form an elastic structure through the spring 19.

[0022] Through the above technical scheme, the adjusting ring 20 has the effect of elasticity under the action of the spring 19. The sealing design on the valve seat has the characteristics of high temperature resistance, corrosion resistance and erosion resistance, which ensures that the sealing surface is not eroded by the well cleaning fluid during well cleaning, and the sealing surface is not corroded by the injected water during water injection, which affects the sealing.

[0023] Specifically, the piston cylinder 3 and the outer tube 10 form a fixed structure through the sealing valve seat 8, and the sealing valve seat 8 is arranged between the piston cylinder 3 and the outer tube 10.

[0024] Through the technical scheme, the piston cylinder 3 is connected with the sealing valve seat 8 through the fastening pin 2, the sealing valve seat 8 is connected with the outer cylinder 10 through the fastening pin 2, and then the piston cylinder 3 is installed and fixed with the outer cylinder 10 through the sealing valve seat 8, the design of the sealing valve seat 8 ensures the inner diameter of the pipe string, so that the normal segmented and layered requirements of the water injection pipe string and the pipe string strength requirements can be met, and the differential pressure design of the sealing backwashing valve 7 is that when the backwashing well pressure is higher than the water injection pressure of 0.5 MPa, the well flushing valve is opened; when the well flushing is stopped, the backwashing valve is automatically closed, and the on-site operation is simple and reliable.

[0025] Specifically, the center pipe 9 forms a fixed structure with the lower joint 18 through the fastening pin 2, and the second sealing ring 5 is arranged between the center pipe 9 and the lower joint 18.

[0026] Through the technical scheme, the center pipe 9 can connect the lower joint 18 under the action of the fastening pin 2, and the sealing property between the two can be improved under the action of the second sealing ring 5.

[0027] Specifically, the inclined surface spacer ring 11 forms a fixed structure with the mounting spacer ring 13 through the sealing assembly 12, and the sealing assembly 12 is arranged between the inclined surface spacer ring 11 and the mounting spacer ring 13.

[0028] Through the technical scheme, in many devices, especially systems involving fluids, such as pumps, compressors, reaction kettles, etc., preventing fluid leakage is crucial, the sealing assembly 12 can effectively prevent internal fluid from overflowing from the connection between the inclined surface spacer ring 11 and the mounting spacer ring 13, maintain the stability of the pressure in the system, avoid fluid waste and environmental pollution, and also prevent external impurities, dust, etc. from entering the system, affecting the normal operation of the equipment and the quality of the fluid.

[0029] Specifically, the outer cylinder 10 forms a fixed structure with the guide shoe 17 through the fastening pin 2, and the fifth sealing ring 16 is arranged between the outer cylinder 10 and the guide shoe 17.

[0030] Through the technical scheme, in the petroleum drilling equipment, there are high-pressure drilling fluids and other fluids in the wellbore, and the fifth sealing ring 16 can prevent the drilling fluid from leaking from the gap between the outer cylinder 10 and the guide shoe 17 to the surrounding environment, avoiding causing drilling fluid loss and pollution to the formation around the well wall.

[0031] Working principle: when the layered water injection well non-moving pipe string hydraulic backwashing circulating device is used, first, the front-stage water injection pipe string such as the packer, the sealing cylinder, the hanger, the water distributor, and the sand control screen pipe is lowered according to the design, the packer is set and sealed, and then the pipe string is pulled out and sent.

[0032] According to the structure, length and sealing surface size of the early stage pipe column, the downhole circulating device and various length short pipes of the matching deployment depth are selected, the assembled downhole circulating device is connected and lowered to the design depth, is docked with the hanger, the pipe column is adjusted, is seated in the tubing hanger, is seated in the wellhead, and normal water injection is realized.

[0033] When backwashing is needed, water injection is stopped, the casing gate is connected with the well flushing pipeline, and is connected with the well flushing equipment, the annulus is pressurized, when the pressure is higher than the water injection pressure by 0.5 MPa, the backwashing channel is opened, the well flushing fluid enters from the annulus, passes through the annulus of several packers and water distributors, enters the tubing and returns to the ground, it is displayed that the annulus flow channel is opened, after well flushing is completed, the oil-casing annulus is depressurized, when the annulus pressure is lower than the water injection pressure by 0.5 MPa, the well flushing channel is closed, and normal water injection is realized.

[0034] The backwashing valve is closed under the action of the spring, normal water injection is realized, and the whole work is completed.

[0035] Although the embodiments of the utility model have been shown and described, it can be understood by those skilled in the art that the embodiments can be changed, modified, replaced and changed in many ways without departing from the principles and spirits, and the appended claims and equivalents thereof are limited.

Claims

1. A downhole circulating device for hydraulic backwashing of a fixed string of a layered water injection well, comprising an upper joint (1), characterized in that: The bottom of the upper joint (1) is provided with a fastening pin (2), one end of the fastening pin (2) is fixedly connected with a piston cylinder (3), the inside of the piston cylinder (3) is provided with a first sealing ring (4), the inside of the upper joint (1) is provided with a second sealing ring (5), the top of the piston cylinder (3) is provided with a sealing backwash valve (7), the top of the sealing backwash valve (7) is provided with a third sealing ring (6), one side of the sealing backwash valve (7) is provided with a sealing valve seat (8), the top of the sealing valve seat (8) is provided with a center tube (9), one side of the sealing valve seat (8) is provided with an outer cylinder (10), the bottom of the outer cylinder (10) is provided with a bevel spacer ring (11), one side of the bevel spacer ring (11) is provided with a sealing assembly (12), one side of the sealing assembly (12) is provided with a mounting spacer ring (13), one side of the mounting spacer ring (13) is provided with a fourth sealing ring (14), the bottom of the outer cylinder (10) is provided with a limiting mandrel (15), the bottom of the outer cylinder (10) is provided with a fifth sealing ring (16), the outside of the fifth sealing ring (16) is provided with a guide shoe (17), one end of the center tube (9) is provided with a lower joint (18), one side of the sealing backwash valve (7) is provided with an adjusting ring (20), one side of the adjusting ring (20) is provided with a spring (19).

2. The layered water injection well fixed string hydraulic clean-out downhole circulating device according to claim 1, characterized in that: The upper joint (1) is fixedly connected with the piston cylinder (3) through the fastening pin (2), and the number of the fastening pin (2) is plural.

3. The layered water injection well fixed string hydraulic clean-out downhole circulating device of claim 1, wherein: The piston cylinder (3) is elastically connected with the adjusting ring (20) through the spring (19).

4. The layered water injection well fixed string hydraulic clean-out downhole circulating device, according to claim 1, characterized in that: The piston cylinder (3) is fixedly connected with the outer cylinder (10) through the sealing valve seat (8), and the sealing valve seat (8) is arranged between the piston cylinder (3) and the outer cylinder (10).

5. The layered water injection well fixed string hydraulic clean-out downhole circulating device, according to claim 1, characterized in that: The center tube (9) is fixedly connected with the lower joint (18) through the fastening pin (2), and the second sealing ring (5) is arranged between the center tube (9) and the lower joint (18).

6. The layered water injection well fixed string hydraulic clean-out downhole circulating device, according to claim 1, characterized in that: The bevel spacer ring (11) is fixedly connected with the mounting spacer ring (13) through the sealing assembly (12), and the sealing assembly (12) is arranged between the bevel spacer ring (11) and the mounting spacer ring (13).

7. The layered water injection well fixed string hydraulic clean-out downhole circulating device, according to claim 1, characterized in that: The outer cylinder (10) is fixedly connected with the guide shoe (17) through the fastening pin (2), and the fifth sealing ring (16) is arranged between the outer cylinder (10) and the guide shoe (17).

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