Canned pump-based closed injection-production alternation tubular column and immovable tubular column-based injection-production alternation method

Abstract

The invention discloses a closed injection-production alternation tubular column based on a canned pump and an injection-production alternation method based on a fixed tubular column. The closed injection-production alternating tubular column based on the canned pump comprises an oil pipe, a perforated pipe connected to the end of the oil pipe, and a positioning steering flow dividing device, an axial switch control valve, a radial switch control valve, the canned pump and a water injection sliding sleeve which are sequentially connected in the axial direction of the oil pipe. In the shaft, the perforated pipe is located in a water injection layer, and the positioning, steering and shunting device is located above a water source layer; the positioning, steering and shunting device comprises a water sampling channel and a water injection channel which are isolated from each other, and the water sampling channel is located on the periphery of the water injection channel. Switching among different production modes of a water injection well, a production well and a water source well can be achieved through one pipe column, immovable pipe column alternation can be conducted at any time according to oil reservoir requirements, the operation cost is saved, and the adjustment operation efficiency of injection and production wells of offshore oilfields is improved.

Description

Technical Field

[0001] The invention relates to the technical field of offshore oil fields, and in particular to a closed injection-production rotation pipe string based on a canned pump and an injection-production rotation method of a fixed pipe string. Background Art

[0002] Some offshore oil fields have problems such as insufficient formation energy, no surface water injection equipment, and high single-well water injection volume. For the above problems, the canned pump closed water injection process is currently widely used to achieve water drive development to supplement formation energy. However, before water injection, the water source layer and the water injection layer often need to be returned separately. The existing canned pump closed water injection process requires a separate string to be lowered. The two string operations result in high operating costs and a long construction period. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a closed injection-production rotation string based on a canned pump and an injection-production rotation method for a fixed string.

[0004] The technical solution adopted by the present invention to solve the technical problem is: to provide a closed injection-production rotation string based on a canned pump, which is used to be lowered into a wellbore, and the string includes an oil pipe, a perforated pipe connected to the end of the oil pipe, a positioning steering diversion device connected in sequence along the axial direction of the oil pipe, an axial switch control valve, a radial switch control valve, a canned pump and a water injection sleeve;

[0005] In the wellbore, the perforated pipe is located in the water injection layer, and the positioning, diversion and diversion device is located above the water source layer; the positioning, diversion and diversion device includes a water collection channel and a water injection channel that are isolated from each other, and the water collection channel is located at the periphery of the water injection channel;

[0006] When the axial switch control valve and the water injection sliding sleeve are closed and the radial switch control valve is opened, the perforated pipe and the water injection channel are connected to the canned pump through the radial switch control valve to form a water injection layer production channel;

[0007] When the axial switch control valve is opened and the radial switch control valve and the water injection sleeve are closed, the water production channel is connected to the canned pump through the axial switch control valve to form a water source layer production flow channel;

[0008] When the axial switch control valve and the water injection sleeve are opened and the radial switch control valve is closed, the water source layer, the water production channel, the axial switch control valve, the canned pump, the water injection sleeve, the water injection channel, the perforated pipe and the water injection layer are connected in sequence to form a water injection flow channel.

[0009] In some embodiments, the canned pump-based closed injection and production rotation string further includes a first inserted seal and a second inserted seal;

[0010] In the wellbore, the first inserted seal is fitted between the oil pipe and the inner wall of the wellbore, and is disposed between the water injection layer and the water source layer. The second inserted seal is fitted between the oil pipe and the inner wall of the wellbore, and is disposed above the water source layer.

[0011] In some embodiments, the closed injection-production rotation string based on a canned pump also includes a well washing sleeve and a safety valve connected in sequence along the axial direction of the oil pipe, a first seating joint connected between the canned pump and the water injection sleeve, and a second seating joint connected between the water injection sleeve and the well washing sleeve.

[0012] In some embodiments, the positioning, steering and diverting device comprises a central tube body with one end closed and an outer tube body sleeved on the periphery of the central tube body;

[0013] The closed end of the central tube body is located inside the outer tube body, and a water injection hole is provided on the outer tube body that radially penetrates the central tube body, and the open end of the central tube body is located outside the outer tube body and axially connected to the oil pipe;

[0014] The first end of the outer tube body is connected to the outer peripheral surface of the open end of the central tube body through a bevel end plug, and the bevel end plug is provided with a plurality of radial through holes; the second end of the outer tube body opposite to the outer tube body extends toward the axial switch control valve and is connected to the axial switch control valve;

[0015] The water injection hole is communicated with the internal channel of the central tube body to form the water injection channel;

[0016] The radial through hole is communicated with the internal channel of the outer tube body to form the water collection channel.

[0017] In some embodiments, the outer tube is formed by overlapping a plurality of joints in the axial direction.

[0018] In some embodiments, the positioning, steering and diverting device further includes a first buckle and a second buckle;

[0019] The first buckle is connected to the open end of the central tube body, and the second buckle is connected to the second end of the outer tube body.

[0020] The present invention also provides a method for injection-production rotation of a fixed pipe column, which adopts any of the above-mentioned closed injection-production rotation pipe columns based on canned pumps, and the method for injection-production rotation of a fixed pipe column comprises the following steps:

[0021] When the production well is in normal production, the axial switch control valve and the water injection sleeve of the pipe string are closed, and the radial switch control valve of the pipe string is opened. The perforated pipe and the water injection channel of the pipe string are connected with the canned pump through the radial switch control valve, and the canned pump is turned on;

[0022] When used as a water source well, the radial switch control valve and the water injection sleeve of the pipe string are closed, and the axial switch control valve of the pipe string is opened. The water collection channel of the pipe string is connected with the canned pump through the axial switch control valve, and the canned pump is turned on;

[0023] When performing closed water injection as an injection well, close the radial switch control valve of the tubing string, open the axial switch control valve and the water injection sleeve of the tubing string, connect the water source layer, water production channel, axial switch control valve, canned pump, water injection sleeve, water injection channel, perforated pipe and water injection layer in sequence, and start the canned pump.

[0024] In some embodiments, when the production well is in normal production, the liquid in the water injection layer enters the oil pipe from the perforated pipe, enters the water injection channel along the oil pipe, and is radially discharged from the head end of the water injection channel and enters the oil casing annulus, and enters the canned pump along the oil casing annulus through the radial switch control valve; the canned pump transports the liquid upward to the ground.

[0025] In some embodiments, when used as a water source well, the liquid in the water source layer enters the water production channel radially, enters the oil pipe along the water production channel, and enters the canned pump through the axial switch control valve; the canned pump transports the liquid upward to the ground.

[0026] In some embodiments, when closed water injection is performed, liquid radially enters the water production channel from the water source layer, enters the oil pipe along the water production channel, and enters the canned pump through the axial switch control valve; the canned pump transports the liquid upward, enters the oil casing annulus through the water injection sleeve, radially enters the water injection channel along the oil casing annulus, passes through the oil pipe along the water injection channel to the perforated pipe, and is output from the perforated pipe and enters the water injection layer.

[0027] The beneficial effects of the present invention are as follows: through the coordination of the water injection sleeve, the radial switch control valve, the axial switch control valve and the positioning steering diversion device on the oil pipe, one trip of the pipe string can realize the switching between different production modes of water injection wells, production wells and water source wells, and can perform fixed conversion rotation at any time according to the needs of the oil reservoir, saving operating costs and improving the adjustment efficiency of injection and production wells in offshore oil fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0029] Figure 1 This is a structural schematic diagram of a pipe column in accordance with an embodiment of the present invention for normal production of a water injection layer;

[0030] Figure 2 This is a schematic structural diagram of a pipe column for water source layer flowback according to an embodiment of the present invention;

[0031] Figure 3 It is a structural schematic diagram of a closed water injection performed by a pipe column according to an embodiment of the present invention;

[0032] Figure 4 It is a structural schematic diagram of a positioning, steering and flow diverting device in a pipe column according to an embodiment of the present invention. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0034] like Figures 1 to 3 As shown, a closed injection-production rotation string based on a canned pump according to an embodiment of the present invention is used to be lowered into a wellbore (also called casing). The string may include an oil pipe 10, a perforated pipe 20, a positioning steering diversion device 30, an axial switching control valve 40, a radial switching control valve 50, a canned pump 60 and a water injection sleeve 70.

[0035] The perforated pipe 20 is connected to the end of the oil pipe 10; the end of the perforated pipe 20 is closed by a round plug. The positioning steering diversion device 30, the axial switch control valve 40, the radial switch control valve 50, the canned pump 60 and the water injection sleeve 70 are connected in sequence along the axial direction of the oil pipe 10.

[0036] In the wellbore, the water source layer is located above the water injection layer (also the oil layer). The pipe string is lowered into the wellbore with the perforated pipe 20 facing downward. The perforated pipe 20 is in the water injection layer, and the holes on the perforated pipe 20 are used to connect the oil pipe 10 and the water injection layer.

[0037] The positioning, steering and diverting device 30 is located above the water source layer and is connected to the perforated pipe 20 through the oil pipe 10. The axial switch control valve 40, the radial switch control valve 50, the canned pump 60 and the water injection sleeve 70 are sequentially connected above the positioning, steering and diverting device 30 along the axial direction of the oil pipe 10.

[0038] It can be understood that each adjacent two structural parts such as between the positioning steering diverter device 30 and the axial switch control valve 40, between the radial switch control valve 50 and the canned pump 60, between the canned pump 60 and the water injection sleeve 70 are also connected by the oil pipe 10 respectively.

[0039] The axial switch control valve 40 is used to control the on-off of the oil pipe 10 in the axial direction. The radial switch control valve 50 is used to control the on-off of the oil pipe 10 in the radial direction. When the axial switch control valve 40 is in an open state, the inside of the oil pipe 10 is axially connected. When the radial switch control valve 50 is in an open state, the oil pipe 10 can be connected to the wellbore in the radial direction.

[0040] The canned pump 60 is a canned electric pump system that provides power for water extraction, oil extraction and water injection.

[0041] The positioning, steering and diverting device 30 comprises a water injection channel 31 and a water collection channel 32 which are isolated from each other. The water collection channel 32 is located at the periphery of the water injection channel 31 .

[0042] like Figure 1 As shown in FIG. 1 , when the axial switch control valve 40 and the water injection sleeve 70 are closed and the radial switch control valve 50 is opened, the perforated pipe 20 and the water injection channel 31 are connected to the canned pump 60 through the radial switch control valve 50 to form a water injection layer production channel. At this time, the water injection layer can be produced to realize the function of a production well (oil production well). Figure 1 As shown by the middle arrow, the liquid enters the oil pipe 10 from the water injection layer through the perforated pipe 20, and then enters the canned pump 60 along the water injection channel 31, the oil casing annulus (the space between the oil pipe and the casing), and the radial switch control valve 50, and is transported upward under the drive of the canned pump 60 until it is discharged to the ground.

[0043] like Figure 2 As shown, when the axial switch control valve 40 is opened and the radial switch control valve 50 and the water injection sleeve 70 are closed, the water production channel 32 is connected to the canned pump 60 through the axial switch control valve 40 to form a water source layer production flow channel. At this time, the water source layer can be produced to realize the function of the water source well. Figure 2 As shown by the middle arrow, the liquid enters the water production channel 32 from the water source layer, and then enters the canned pump 60 along the oil pipe 10 through the axial switch control valve 40, and is transported upward under the drive of the canned pump 60 until it is discharged to the ground.

[0044] When the general Figure 1 The axial switch control valve 40 in the pipe string is turned from the closed state to the open state, the radial switch control valve 50 is turned from the open state to the closed state, and the water injection sliding sleeve 70 remains closed (as shown in FIG. Figure 2 As shown), it is possible to switch from a production well to a water source well without moving the tubing string, and vice versa, it is also possible to switch from a water source well to a production well without moving the tubing string.

[0045] like Figure 3 As shown, when the axial switch control valve 40 and the water injection sleeve 70 are opened and the radial switch control valve 50 is closed, the water source layer, the water collection channel 32, the axial switch control valve 40, the canned pump 60, the water injection sleeve 70, the water injection channel 31, the perforated pipe 20 and the water injection layer are connected in sequence to form a water injection flow channel. Figure 3As shown by the middle arrow, the liquid enters the water production channel 32 from the water source layer, then passes through the axial switch control valve 40 along the oil pipe 10 and enters the canned pump 60, and is transported upward under the drive of the canned pump 60, passes through the water injection sliding sleeve 70 and enters the oil casing annulus (the space between the oil pipe and the casing), and then flows downward into the water injection channel 31, passes through the oil pipe 10 along the water injection channel 31 to the perforated pipe 20, and is output from the perforated pipe 20 and enters the water injection layer.

[0046] When the general Figure 1 The axial switch control valve 40 and the water injection sleeve 70 in the pipe string are turned from the closed state to the open state, and the radial switch control valve 50 is turned from the open state to the closed state (as shown in FIG. Figure 3 As shown in FIG. 1 , it is possible to switch from a production well to an injection well without moving the tubing string.

[0047] When the general Figure 2 After the water injection sleeve 70 in the pipe string is turned from the closed state to the open state (as shown in FIG. Figure 3 As shown in the figure), the axial switch control valve remains in an open state, and the radial switch control valve remains in a closed state, so that the water source well can be switched to the water injection well without moving the pipe string.

[0048] In some embodiments, in combination Figure 1 and Figure 4 The positioning, steering and flow diverting device 30 includes a central tube body 33 and an outer tube body 34. The central tube body 33 is a tube body structure with one end closed and the other end open. The outer tube body 34 is sleeved on the outer side of the central tube body 33, and the closed end (head end) of the central tube body 33 is inside the outer tube body 34, and the open end of the central tube body 33 is outside the outer tube body 34 and axially connected to the oil pipe 10.

[0049] The outer tube body 34 is provided with a water injection hole 35 which radially penetrates to the closed end of the central tube body 33 and is isolated from the inner passage of the outer tube body 34. The water injection hole 35 is connected with the inner passage of the central tube body 33 to form a water injection passage 31.

[0050] The first end of the outer tube body 34 is connected to the outer circumferential surface of the open end of the central tube body 33 through the bevel end plug 36, so that the first end of the outer tube body 34 ends at the outer side of the central tube body 33 through the bevel end plug 36. The bevel end plug 36 is provided with a plurality of radial through holes 37, which are arranged at intervals along the circumference of the bevel end plug 36 and communicate with the inner and outer spaces of the bevel end plug 36. The radial through holes 37 are communicated with the internal channel of the outer tube body 34 to form a water collection channel 32. The second end opposite to the outer tube body 34 extends in the axial switch control valve direction 40 and is connected to the axial switch control valve 40.

[0051] In some embodiments, the outer tube body 34 is formed by overlapping a plurality of joints in the axial direction, and the insides of the joints are connected to form the water collection channel 32 .

[0052] Furthermore, the positioning, steering and diverting device 30 may also include a first buckle 38 and a second buckle 39. The first buckle 37 is connected to the open end of the central tube body 33, and the first buckle 37 is used to buckle with the oil pipe 10. The second buckle 38 is connected to the second end of the outer tube body 34, and is used to buckle with the oil pipe 10, and the axial switch control valve 40 is connected through the oil pipe 10.

[0053] Furthermore, if Figure 1 As shown, the tubing string also includes a first insert seal 101 and a second insert seal 102. In the wellbore, the first insert seal 101 is fitted between the oil pipe 10 and the inner wall of the wellbore, and is disposed between the water injection layer and the water source layer, and the second insert seal 102 is fitted between the oil pipe 10 and the inner wall of the wellbore, and is disposed above the water source layer.

[0054] The tubing string also includes a well-washing sleeve 80 and a safety valve 90 connected in sequence along the axial direction of the oil pipe 10, a first seating joint 71 connected between the canned pump 60 and the water injection sleeve 70, and a second seating joint 72 connected between the water injection sleeve 70 and the well-washing sleeve 80; the safety valve 90 is located near the wellhead of the wellbore on the tubing string. In the axial direction of the tubing string, the first seating joint 71, the water injection sleeve 70, the second seating joint 72, the well-washing sleeve 80 and the safety valve 90 can be connected in sequence.

[0055] The tubing string may further include an ESP packer 103 and a centralizer 104. The ESP packer 103 is sleeved between the outer periphery of the tubing 10 and the inner wall of the wellbore, and is located between the second landing joint 72 and the well washing sleeve 80 in the axial direction of the tubing string. The centralizer 104 is sleeved on the outer periphery of the tubing 10 and is located between the positioning, steering and diverting device 30 and the axial switch control valve 40.

[0056] The pipe column of the present invention cooperates with the radial switch control valve 50, the axial switch control valve 40 and the positioning steering diversion device 30, and is combined with the setting of the canned pump 60 to increase the liquid accommodation space, so as to realize the return of the fixed pipe column to the closed water injection, and realize the large-displacement closed water injection; the displacement can reach 3000m 3 / sky.

[0057] The method for injection-production rotation of a fixed pipe string implemented by the pipe string of the present invention may include the following steps:

[0058] The pipe string is lowered into the wellbore in advance, wherein the first inserted seal 101 is disposed between the water injection layer and the water source layer, and the second inserted seal 102 is disposed above the water source layer.

[0059] refer to Figure 1When the production well is in normal production, the axial switch control valve 40 and the water injection sleeve 70 of the tubing are closed, and the radial switch control valve 50 of the tubing is opened. The perforated pipe 20 and the water injection channel 31 of the tubing are connected to the canned pump 60 through the radial switch control valve 50, and the canned pump 60 is turned on to realize the production of the water injection layer.

[0060] refer to Figure 2 When used as a water source well, close the radial switch control valve 50 and the water injection sleeve 70 of the tubing string, open the axial switch control valve 40 of the tubing string, and connect the water production channel 32 of the tubing string with the canned pump 60 through the axial switch control valve 40. Turn on the canned pump 60 to realize water source layer production.

[0061] refer to Figure 3 When the closed water injection is performed as an injection well, the radial switch control valve 50 of the pipe string is closed, and the axial switch control valve 40 and the water injection sleeve 70 of the pipe string are opened. The water source layer, the water production channel 32, the axial switch control valve 40, the canned pump 60, the water injection sleeve 70, the water injection channel 31, the perforated pipe 20 and the water injection layer are connected in sequence, and the canned pump 60 is turned on to realize closed water injection.

[0062] In the above-mentioned injection-production rotation method without moving the tubing string, it is possible to switch from the production well to the water source well without moving the tubing string, and it is also possible to switch from the water source well to the water injection well without moving the tubing string.

[0063] It can be understood that before the above-mentioned production well is converted into a water source well, the canned pump 60 is first stopped (the pump is stopped), and then the radial switch control valve 50 and the water injection sleeve 70 of the tubing are closed, the axial switch control valve 40 of the tubing is opened, and the canned pump 60 is turned on to produce the water source layer.

[0064] Before converting the water source well into a closed injection well, the pump should also be stopped before performing related operations.

[0065] In some embodiments, Figure 1 and Figure 4 As shown, when the water injection layer is produced as a production well, the liquid in the water injection layer enters the oil pipe 10 from the perforated pipe 20, enters the water injection channel 31 along the oil pipe 10, and then is radially discharged from the head end of the water injection channel 31 of the positioning steering diversion device 30 and enters the barrel, along the space between the wellbore and the oil pipe (the oil casing annulus) and enters the canned pump 60 through the radial switching control valve 50; the canned pump 60 transports the liquid upward to the ground.

[0066] In some embodiments, Figure 2 and Figure 4As shown, when the water source well is used as a water source layer for production, the liquid in the water source layer enters the water production channel 32 of the positioning and steering diversion device 30 radially, enters the oil pipe 10 along the water production channel 32, and enters the canned pump 60 through the axial switch control valve 40; the canned pump 60 transports the liquid upward to the ground.

[0067] In some embodiments, when closed water injection is performed, the liquid radially enters the water production channel 32 of the positioning, steering and diverting device 30 from the water source layer, enters the oil pipe 10 along the water production channel 32, and enters the canned pump 60 through the axial switch control valve 40; the canned pump 60 transports the liquid upward, enters the wellbore through the water injection sleeve 70, and radially enters the water injection channel 31 of the positioning, steering and diverting device 30 along the space between the wellbore and the oil pipe (casing annulus), passes through the oil pipe along the water injection channel 31 to the perforated pipe 20, and is output from the perforated pipe 20 and enters the water injection layer.

[0068] In summary, the present invention realizes the rotation among production wells, water source wells and water injection wells under the fixed pipe string through the switch control of the water injection sleeve, the radial switch control valve and the axial switch control valve. The present invention is easy to use and has reliable effect. The present invention can be widely used in water-driven development of oil fields without surface water injection equipment, and provides a solution for the economical and efficient development of oil fields without surface water injection equipment, thereby saving the process and investment of surface water injection equipment.

[0069] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A closed injection-production rotation string based on a canned pump, used for lowering into a wellbore, characterized in that: The closed injection-production rotation string based on the canned pump includes an oil pipe, a perforated pipe connected to the end of the oil pipe, a positioning steering diversion device, an axial switch control valve, a radial switch control valve, a canned pump and a water injection sleeve connected in sequence along the axial direction of the oil pipe; In the wellbore, the perforated pipe is located in the water injection layer, and the positioning, diversion and diversion device is located above the water source layer; the positioning, diversion and diversion device includes a water collection channel and a water injection channel that are isolated from each other, and the water collection channel is located at the periphery of the water injection channel; When the axial switch control valve and the water injection sliding sleeve are closed and the radial switch control valve is opened, the perforated pipe and the water injection channel are connected to the canned pump through the radial switch control valve to form a water injection layer production channel; When the axial switch control valve is opened and the radial switch control valve and the water injection sleeve are closed, the water production channel is connected to the canned pump through the axial switch control valve to form a water source layer production flow channel; When the axial switch control valve and the water injection sleeve are opened and the radial switch control valve is closed, the water source layer, the water production channel, the axial switch control valve, the canned pump, the water injection sleeve, the water injection channel, the perforated pipe and the water injection layer are connected in sequence to form a water injection flow channel.

2. The closed injection-production rotation string based on canned pump according to claim 1 is characterized in that: The closed injection-production rotation string based on the canned pump also includes a first inserted seal and a second inserted seal; In the wellbore, the first inserted seal is fitted between the oil pipe and the inner wall of the wellbore, and is disposed between the water injection layer and the water source layer. The second inserted seal is fitted between the oil pipe and the inner wall of the wellbore, and is disposed above the water source layer.

3. The closed injection-production rotation string based on canned pump according to claim 1 is characterized in that: The closed injection-production rotation string based on the canned pump also includes a well-washing sleeve and a safety valve connected in sequence along the axial direction of the oil pipe, a first seating joint connected between the canned pump and the water injection sleeve, and a second seating joint connected between the water injection sleeve and the well-washing sleeve.

4. The closed injection-production rotation string based on a canned pump according to any one of claims 1 to 3, characterized in that: The positioning, steering and diverting device comprises a central tube body with one end closed and an outer tube body sleeved on the outer periphery of the central tube body; The closed end of the central tube body is located inside the outer tube body, and a water injection hole is provided on the outer tube body that radially penetrates the central tube body, and the open end of the central tube body is located outside the outer tube body and axially connected to the oil pipe; The first end of the outer tube body is connected to the outer peripheral surface of the open end of the central tube body through a bevel end plug, and the bevel end plug is provided with a plurality of radial through holes; the second end of the outer tube body opposite to the outer tube body extends toward the axial switch control valve and is connected to the axial switch control valve; The water injection hole is communicated with the internal channel of the central tube body to form the water injection channel; The radial through hole is communicated with the internal channel of the outer tube body to form the water collection channel.

5. The closed injection-production rotation string based on canned pump according to claim 4 is characterized in that: The outer tube body is formed by overlapping a plurality of joints in the axial direction.

6. The closed injection-production rotation string based on canned pump according to claim 4 is characterized in that: The positioning, steering and diverting device also includes a first buckle and a second buckle; The first buckle is connected to the open end of the central tube body, and the second buckle is connected to the second end of the outer tube body.

7. A method for injection-production rotation without moving a pipe string, characterized in that: The closed injection-production rotation string based on a canned pump according to any one of claims 1 to 6 is adopted, and the injection-production rotation method of the fixed string comprises the following steps: When the production well is in normal production, the axial switch control valve and the water injection sleeve of the pipe string are closed, and the radial switch control valve of the pipe string is opened. The perforated pipe and the water injection channel of the pipe string are connected with the canned pump through the radial switch control valve, and the canned pump is turned on; When used as a water source well, the radial switch control valve and the water injection sleeve of the pipe string are closed, and the axial switch control valve of the pipe string is opened. The water collection channel of the pipe string is connected with the canned pump through the axial switch control valve, and the canned pump is turned on; When performing closed water injection as an injection well, close the radial switch control valve of the tubing string, open the axial switch control valve and the water injection sleeve of the tubing string, connect the water source layer, water production channel, axial switch control valve, canned pump, water injection sleeve, water injection channel, perforated pipe and water injection layer in sequence, and start the canned pump.

8. The method for injection and production rotation of a fixed pipe string according to claim 7, characterized in that: When the production well is in normal production, the liquid in the water injection layer enters the oil pipe from the perforated pipe, enters the water injection channel along the oil pipe, is radially discharged from the head end of the water injection channel and enters the oil casing annulus, and enters the canned pump along the oil casing annulus through the radial switch control valve; the canned pump transports the liquid upward to the ground.

9. The method for injection and production rotation of a fixed pipe string according to claim 7, characterized in that: When used as a water source well, the liquid in the water source layer enters the water production channel radially, enters the oil pipe along the water production channel, and enters the canned pump through the axial switch control valve; the canned pump transports the liquid upward to the ground.

10. The method for injection and production rotation of a fixed pipe string according to claim 7, characterized in that: When used as an injection well for closed water injection, liquid radially enters the water production channel from the water source layer, enters the oil pipe along the water production channel, and enters the canned pump through the axial switch control valve; the canned pump transports the liquid upward, enters the oil casing annulus through the water injection sleeve, radially enters the water injection channel along the oil casing annulus, passes through the oil pipe along the water injection channel to the perforated pipe, and is output from the perforated pipe and enters the water injection layer.

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