Water injection packer

Abstract

The invention belongs to the field of oilfield exploitation, and particularly relates to a water injection packer which comprises a central pipe, the upper end and the lower end of the central pipe are connected with an upper connector and a lower connector respectively, a plugging mechanism is connected to the position, close to the middle, of the central pipe, and the plugging mechanism comprises a rubber cylinder and a cylinder sleeve which are connected to the outer side wall of the central pipe in a sleeving mode. The sleeve is connected with the central pipe in an up-and-down sliding mode, and the rubber sleeve is arranged outside the sleeve; an extrusion propelling mechanism is arranged below the outer rubber sleeve of the central pipe and comprises a cylinder sleeve, a piston, a backwashing sleeve and a backwashing valve, the cylinder sleeve is arranged outside the lower connector in a sleeving mode and fixedly connected with the lower connector, the piston is arranged above the lower connector between the cylinder sleeve and the central pipe, the backwashing valve is arranged above the piston, and the backwashing sleeve is fixedly connected with the backwashing valve. The backwashing sleeve is sleeved outside the backwashing valve, the backwashing sleeve is fixedly connected with the cylinder sleeve, and the lower joint is connected with the cylinder sleeve through a control pin; the device is reliable in performance and simple in structure.

Description

Technical Field

[0001] The invention belongs to the field of oil field exploitation, and in particular relates to a water injection packer. Background Art

[0002] Since the water injection packer is required to work for a long time underground, the backwashing mechanism and the sealing rubber tube of the water injection packer currently in use have some defects. The backwashing mechanism is a very important structure of the water injection packer. The backwashing mechanism of the current water injection packer fails to seal because the sealing ring and the sealing rubber tube are easy to age and the sealing ring is easy to fall off. Summary of the invention

[0003] The purpose of the present invention is to solve the problems existing in the prior art, thereby providing a water injection packer for the oil field water injection field. The backwash mechanism can ensure that the backwash valve is in a closed (effective) state during water injection, thereby preventing the backwash valve of the packer from accidentally opening or leaking, thereby causing sealing failure, and effectively improving the success rate of the packer's sealing.

[0004] The object of the present invention is achieved in this way: a water injection packer comprises a central tube, the upper end and the lower end of the central tube are respectively connected to an upper joint and a lower joint, a sealing mechanism is connected to the central tube near the middle, the sealing mechanism comprises a rubber tube and a tube sleeve sleeved on the outer wall of the central tube, the tube sleeve and the central tube are slidably connected up and down, and the rubber tube is arranged on the outside of the tube sleeve; an extrusion and propulsion mechanism is arranged below the external rubber tube of the central tube, the extrusion and propulsion mechanism comprises a cylinder sleeve, a piston, a backwash sleeve, and a backwash valve, the cylinder sleeve is sleeved on the outside of the lower joint and is fixedly connected to the lower joint, the cylinder sleeve and the central tube are connected to the central tube, and the sealing mechanism comprises a rubber tube sleeve and a tube sleeve sleeve, the rubber tube sleeve and the central tube are connected to the central tube, and the sealing mechanism comprises a rubber tube sleeve and a piston, a backwash sleeve and a backwash valve, the cylinder sleeve is sleeved on the outside of the lower joint and is fixedly connected to the lower joint, and the cylinder sleeve and the central tube are connected to the central tube. A piston is arranged above the lower joint between the pipes, a backwash valve is arranged above the piston, the backwash sleeve is sleeved on the outside of the backwash valve, the backwash sleeve is fixedly connected to the cylinder sleeve, and the lower joint and the cylinder sleeve are connected by a control pin; a seating locking mechanism is arranged above the external rubber sleeve of the central pipe, an unsealing mechanism is connected to the seating locking mechanism, a backwash channel is arranged between the sleeve and the central pipe, a backwash hole C is arranged on the side of the locking sleeve, a backwash hole B is arranged on the side of the sleeve, the backwash hole C and the backwash hole B are connected to the backwash channel, and a backwash hole A is arranged on the side of the backwash sleeve.

[0005] Furthermore, the number of the rubber cylinders outside the cylinder sleeve is not less than 2 groups, and a spacer ring is provided between two adjacent groups of rubber cylinders to ensure the sealing effect.

[0006] Furthermore, the sealing and locking mechanism includes a locking ring arranged above the rubber sleeve outside the sleeve, the locking ring and the sleeve are fixedly connected, a locking sleeve is arranged above the locking ring, the top of the locking sleeve is fixedly connected to the upper joint, and the inner side surface of the locking sleeve is provided with an internal thread matching the external thread on the outer side surface of the locking ring. When the sleeve drives the locking ring to move toward the upper joint, the locking ring moves forward to the position of the internal thread of the locking sleeve, the external thread of the locking ring engages with the internal thread of the locking sleeve and is locked to prevent the locking ring from retreating in the reverse direction, thereby completing the sealing process of the packer.

[0007] Furthermore, a seat sleeve is connected between the locking ring and the tube sleeve, the seat sleeve and the tube sleeve are connected by an unsealing mechanism, the locking ring and the seat sleeve are connected by a thread, the seat sleeve and the tube sleeve are separated by the unsealing mechanism, the rubber tube rebounds, and the unsealing process is completed.

[0008] Furthermore, the unsealing mechanism includes an unsealing pin connected between the seat sleeve and the tube sleeve. When the water injection pipe column needs to be lifted out, the water injection pipe column is lifted up. At this time, the rubber sleeve and the inner wall of the casing are tightly attached to each other, and there is a certain friction force. The lifting force of the pipe column is transmitted to the rubber sleeve through the upper joint of the water injection packer, the locking sleeve thread, the locking ring, the seat sleeve, the unsealing pin and the tube sleeve, etc., to overcome the friction force between the rubber sleeve and the casing. When the friction force is greater than the shear force of the unsealing pin, the shear section of the unsealing pin is cut off, the seat sleeve and the tube sleeve are separated, and the rubber sleeve rebounds to complete the unsealing process.

[0009] Furthermore, a retaining ring is connected to the bottom end of the locking sleeve, the bottom end surface of the retaining ring abuts against the top end surface of the rubber sleeve, and the retaining ring is connected to the sleeve in an up-and-down sliding manner.

[0010] Furthermore, a spring and a limit sleeve are arranged between the lower joint in the cylinder sleeve and the piston. The limit sleeve limits the maximum downward movement position of the piston to prevent the sealing packing in the piston from failing to seal. The spring is used to force the backwash valve to close the backwash hole on the backwash sleeve upward after backwashing the well.

[0011] Furthermore, the top of the inner side surface of the backwash valve is arranged in a step shape, and the inner step surface of the top of the backwash valve is sleeved with the outer step surface of the bottom end of the sleeve, and an annular groove is formed between the backwash sleeve and the step surface at the bottom of the sleeve, and a sealing gasket is arranged in the annular groove. The sealing gasket is installed in the rectangular groove formed by the sleeve and the backwash sleeve to effectively prevent it from falling off.

[0012] Beneficial effects of the present invention: The present invention adopts a pressure differential hydraulic forced closing backwash valve mode, and the pressure differential area is large, forming a large backwash valve closing pressure. After the well is washed, no blocking problem will occur during water injection, and the performance is reliable and the structure is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 The present invention is a schematic diagram of the cross-sectional structure of a water injection packer.

[0015] Description of reference numerals: 1. Center tube; 2. Upper joint; 3. Lower joint; 4. Cylinder sleeve; 5. Rubber cylinder; 6. Cylinder sleeve; 7. Piston; 8. Backwash sleeve; 9. Backwash valve; 10. Control pin; 11. Backwash channel; 12. Backwash hole C; 13. Backwash hole B; 14. Backwash hole A; 15. Lock ring; 16. Lock sleeve; 17. Seat sleeve; 18. Unsealing pin; 19. Retaining ring; 20. Spring; 21. Limit sleeve; 22. Spacer ring; 23. Sealing gasket. DETAILED DESCRIPTION

[0016] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of the present invention, it is necessary to understand that the terms "length", "width", "up", "down", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0018] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0021] In one embodiment of the present invention, Figure 1 As shown, a water injection packer comprises a central tube 1, wherein the upper end and the lower end of the central tube 1 are respectively connected to an upper joint 2 and a lower joint 3, a sealing mechanism is connected to the central tube 1 at a position close to the middle, the sealing mechanism comprises a rubber tube 5 and a tube sleeve 4 sleeved on the outer wall of the central tube 1, the tube sleeve 4 and the central tube 1 are slidably connected up and down, and the rubber tube 5 is arranged on the outside of the tube sleeve 4; an extrusion and propulsion mechanism is arranged below the external rubber tube 5 of the central tube 1, the extrusion and propulsion mechanism comprises a cylinder sleeve 6, a piston 7, a backwash sleeve 8, and a backwash valve 9, the cylinder sleeve 6 is sleeved on the outside of the lower joint 3 and is fixedly connected to the lower joint 3, and a sealing mechanism is arranged above the lower joint 3 between the cylinder sleeve 6 and the central tube 1 A piston 7 is provided, a backwash valve 9 is provided above the piston 7, the backwash sleeve 8 is sleeved on the outside of the backwash valve 9, the backwash sleeve 8 is fixedly connected to the cylinder sleeve 6, and the lower joint 3 is connected to the cylinder sleeve 6 by a control pin 10; a seating locking mechanism is provided above the external rubber sleeve 5 of the central tube 1, and an unsealing mechanism is connected to the seating locking mechanism, a backwash channel 11 is provided between the sleeve 4 and the central tube 1, a backwash hole C12 is provided on the side of the lock sleeve 16, a backwash hole B13 is provided on the side of the sleeve 4, the backwash hole C12 and the backwash hole B13 are connected to the backwash channel 11, and a backwash hole A14 is provided on the side of the backwash sleeve 8.

[0022] In one embodiment of the present invention, Figure 1 As shown, the number of the rubber tubes 5 outside the tube sleeve 4 is not less than 2 groups, and a spacer ring 22 is provided between two adjacent groups of rubber tubes 5 to ensure the sealing effect.

[0023] In one embodiment of the present invention, Figure 1As shown, the sealing mechanism includes a locking ring 15 arranged above the rubber sleeve 5 outside the sleeve 4, the locking ring 15 is fixedly connected to the sleeve 4, a locking sleeve 16 is arranged above the locking ring 15, the top of the locking sleeve 16 is fixedly connected to the upper joint 2, and the inner side surface of the locking sleeve 16 is provided with an internal thread matching the external thread on the outer side surface of the locking ring 15. When the sleeve 4 drives the locking ring 15 to move toward the upper joint 2, the locking ring 15 moves forward to the position of the internal thread of the locking sleeve 16, the external thread of the locking ring 15 engages with the internal thread of the locking sleeve 16, and is locked to prevent the locking ring 15 from retreating in the reverse direction, thereby completing the sealing process of the packer.

[0024] In one embodiment of the present invention, Figure 1 As shown, a seat sleeve 17 is connected between the locking ring 15 and the tube sleeve 4, and the seat sleeve 17 and the tube sleeve 4 are connected by an unsealing mechanism. The locking ring 15 and the seat sleeve 17 are connected by threads, and the seat sleeve 17 and the tube sleeve 4 are separated by the unsealing mechanism, so that the rubber sleeve 5 rebounds, and the unsealing process is completed.

[0025] In one embodiment of the present invention, Figure 1 As shown, the unsealing mechanism includes an unsealing pin 18 connected between the seat sleeve 17 and the tube sleeve 4. When the water injection pipe column needs to be lifted out, the water injection pipe column is lifted up. At this time, the rubber tube 5 is tightly attached to the inner wall of the casing, and there is a certain friction force. The lifting force of the pipe column is transmitted to the rubber tube 5 through the upper joint 2 of the water injection packer, the locking sleeve 16 thread, the locking ring 15, the seat sleeve 17, the unsealing pin 18 and the tube sleeve 4, etc., to overcome the friction between the rubber tube 5 and the casing. When the friction force is greater than the shear force of the unsealing pin 18, the shear section of the unsealing pin 18 is cut off, the seat sleeve 17 is separated from the tube sleeve 4, and the rubber tube 5 rebounds to complete the unsealing process.

[0026] In one embodiment of the present invention, Figure 1 As shown, a retaining ring 19 is connected to the bottom end of the locking sleeve 16 , and the bottom end surface of the retaining ring 19 abuts against the top end surface of the rubber sleeve 5 , and the retaining ring 19 is connected to the sleeve 4 in an upward and downward sliding manner.

[0027] In one embodiment of the present invention, Figure 1 As shown, a spring 20 and a limit sleeve 21 are provided between the lower joint 3 in the cylinder sleeve 6 and the piston 7. The limit sleeve 21 limits the maximum downward movement position of the piston 7 to prevent the sealing packing in the piston 7 from failing to seal. The spring 20 is used to force the backwash valve 9 to close the backwash hole on the backwash sleeve 8 upward after backwashing the well.

[0028] In one embodiment of the present invention, Figure 1As shown, the top of the inner side surface of the backwash valve 9 is set to be stepped, and the inner step surface of the top of the backwash valve 9 is sleeved with the outer step surface of the bottom end of the sleeve 4, and an annular groove is formed between the backwash sleeve 8 and the bottom step surface of the sleeve 4. A sealing gasket 23 is arranged in the annular groove. The sealing gasket 23 is installed in the rectangular groove formed by the sleeve 4 and the backwash sleeve 8 to effectively prevent it from falling off.

[0029] In one embodiment of the present invention, Figure 1As shown, a water injection packer includes an upper joint 2, a cylinder sleeve 6, a control pin 10, a central tube 1, a limit sleeve 21, a spring 20, a piston 7, a backwash valve 9, a sealing gasket, a cylinder sleeve 4, a rubber cylinder 5, a spacer ring 22, a retaining ring 19, an unsealing pin 18, a seat sleeve 17, a locking ring 15, a locking sleeve 16, an upper joint 2, etc., wherein the upper and lower ends of the central tube 1 are provided with threads, and the upper and lower joints 3 are provided with threads inside and outside, and the upper and lower joints 3 are connected with the outer threads of the upper and lower ends of the central tube 1 through the inner threads, and the The limiting sleeve 21, the piston 7, the backwash valve 9, and the sleeve 4 are sequentially sleeved from bottom to top on the periphery of the central tube 1. The lower end of the limiting sleeve 21 is supported on the upper end surface of the lower joint 3. The spring 20 is placed between the lower joint 3 and the piston 7 and sleeved on the periphery of the limiting sleeve 21. The outer surface of the sleeve 4 is set in a step shape. The lower third step is provided with a thread. The upper step is provided with a backwash hole 2 and a pin insertion hole. The backwash valve 9 is located at the lower end of the sleeve 4. The backwash valve 9 is stepped inside. The inner step at the upper end coincides with the outer step at the lower end of the sleeve 4, and the two are sleeved together. The rubber sleeve 5, the spacer ring 22, the retaining ring 19, and the seat sleeve 17 are sleeved on the upper end step of the sleeve 4 in sequence from bottom to top. The seat sleeve 17 is provided with a pin thread hole, and a special thread is provided on the outer surface. The unsealing pin 18 is divided into a thread section and a shear section. The shear section of the unsealing pin 18 is inserted into the pin jack of the upper step of the sleeve 4, and the thread section of the unsealing pin 18 is threaded with the thread hole of the seat sleeve 17 The seat sleeve 17 and the cylinder sleeve 4 are fixed together by the unsealing pin 18. The lock ring 15 is provided with special threads inside and outside, and is sleeved with the special threads outside the seat sleeve 17 through the internal special threads. The outer surface of the retaining ring 19 is stepped, and the upper step is provided with threads. The inner surface of the lock sleeve 16 is stepped, and threads, backwash holes 3, special threads and threads are provided in sequence on different steps. The retaining ring 19 and the lower joint 3 are connected through the threads, and are sleeved on the outer periphery of the two.The backwash sleeve 8, cylinder sleeve 6, sealing gasket, etc. are sequentially arranged at the lower end of the cylinder sleeve 4. The upper end of the backwash sleeve 8 is provided with an inner thread, the lower end is provided with an outer thread, and a backwash hole 1 is provided in the middle. The backwash sleeve 8 is connected to the third step thread of the cylinder sleeve 4 through the inner thread. The backwash sleeve 8 and the lower step of the cylinder sleeve 4 form an annular groove, in which the sealing gasket is placed. The upper end of the cylinder sleeve 6 is provided with an inner thread, and the lower end is provided with a pin thread hole. The cylinder sleeve 6 is connected to the backwash sleeve 8 through the inner thread, and is fixed to the lower joint 3 through the control pin 10. The control pin 10 is divided into a thread section and a shear section. The shear section of the control pin 10 is inserted into the pin groove of the lower joint 3. The thread section of the control pin 10 is threadedly connected to the thread hole of the lower joint 3. The spring 20, the limit sleeve 21, the piston 7, the backwash valve 9, and the sealing gasket are placed in the annular space formed by the cylinder sleeve 6, the backwash sleeve 8 and the central pipe 1. ;

[0030] The working process includes the following steps: The first step is to connect a water injection packer and other supporting tools together. The connection order is: tubing + a water injection packer + tubing + water distributor + tubing + other supporting tools, and then lower the water injection string to the designed position.

[0031] The second step is to connect ground cement trucks and other pumping equipment to the pipe string, inject water pressure into the pipe string, and seal the water injection packer. The water pressure enters the piston 7 cavity through the pipe string, a water injection packer upper joint 2, and the water inlet channel of the center pipe 1 to push the piston 7. The thrust of the piston 7 is transmitted to the control pin 10 through the backwash valve 9 and the cylinder sleeve 6, and the shear section of the control pin 10 is cut off. Then, the backwash valve 9, the backwash sleeve 8, and the cylinder sleeve 4 are pushed up in turn, driving the cylinder sleeve 6, the seat sleeve 17 and the lock ring 15 to move upward, pushing and compressing the rubber sleeve 5. As the pressure continues to increase, the radial size of the rubber sleeve 5 gradually increases due to extrusion, and finally the annulus between the oil pipe and the casing is sealed to achieve the purpose of plugging. When the pressure increases and the piston 7 moves forward a certain distance, the lock ring 15 moves forward to the position of the inner thread of the lock sleeve 16, and the outer thread of the lock ring 15 engages with the inner thread of the lock sleeve 16 and is locked to prevent the lock ring 15 from retreating in the reverse direction, completing the sealing process of the packer, and removing the sealing and pressure equipment to complete the well.

[0032] The third step is to inject water into the pipe column during water injection. The water pressure enters the piston 7 cavity through the pipe column, the upper joint 2 of the water injection packer, and the water inlet channel of the central pipe 1, exerting pressure on the piston 7. The pressure is then exerted on the backwash valve 9 and the backwash sleeve 8. The backwash sleeve 8 squeezes the sleeve 4, and the sleeve 4 squeezes the rubber sleeve 5, so that the rubber sleeve 5 is in a compressed state. When the downward pressure of the water injection packer is greater than the upward pressure, the pressure at the bottom of the packer always makes the packer rubber sleeve 5 in an upward squeeze state. Due to the upward thrust of the piston 7 and the greater area of ​​the lower end of the backwash valve 9 than the upper end, the backwash valve 9 is in an upward push state and is firmly closed. When the downward pressure of the water injection packer is less than the upward pressure, the upper pressure of the packer makes the packer rubber cylinder 5 in a downward extrusion state to form a downward thrust. After a part of this force is offset by the upward thrust provided by the piston 7, it is transmitted to the unsealing pin 18 through the sleeve 4. Since the shearing force of the unsealing pin 18 is greater than this force, it is ensured that the packer is in a seated and blocked state. At this time, the upward pressure on the backwash valve 9 is greater than the downward pressure, but since the upper end area of ​​the backwash valve 9 is smaller than the lower end area, coupled with the upward thrust of the piston 7, the lower force on the backwash valve 9 is still greater than the upper force, and the backwash valve 9 is firmly closed in an upward push state.

[0033] The fourth step is to inject water pressure between the oil pipe and the casing during backwashing. The water pressure flows downward through the oil casing annulus into the backwash hole 3 on the water injection packer lock sleeve 16, and pushes the backwash valve 9 downward through the backwash hole 2 and the backwash channel 11 to make the backwash hole 1 unobstructed, so that the backwash channel 11 is unobstructed, and the oil, sand, etc. are flushed out by continuous backwashing.

[0034] The fifth step, when it is necessary to pull out the water injection pipe column, lift the water injection pipe column. At this time, the rubber tube 5 is tightly attached to the inner wall of the casing, and there is a certain friction force. The lifting force of the pipe column is transmitted to the rubber tube 5 through the upper joint 2 of the water injection packer, the locking sleeve 16 thread, the locking ring 15, the seat sleeve 17, the unsealing pin 18 and the sleeve 4, etc., to overcome the friction between the rubber tube 5 and the casing. When the friction force is greater than the shear force of the unsealing pin 18, the shear section of the unsealing pin 18 is cut off, the seat sleeve 17 is separated from the sleeve 4, and the rubber tube 5 rebounds to complete the unsealing process.

[0035] The above are only preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementations of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A water injection packer, comprising a central tube (1), wherein the upper end and the lower end of the central tube (1) are respectively connected to an upper joint (2) and a lower joint (3), wherein: A plugging mechanism is connected to a position near the middle of the center tube (1), the plugging mechanism comprising a rubber sleeve (5) and a sleeve (4) sleeved on the outer wall of the center tube (1), the sleeve (4) and the center tube (1) being slidably connected up and down, the rubber sleeve (5) being arranged outside the sleeve (4); an extrusion and propulsion mechanism is arranged below the rubber sleeve (5) outside the center tube (1), the extrusion and propulsion mechanism comprising a cylinder sleeve (6), a piston (7), a backwash sleeve (8), and a backwash valve (9), the cylinder sleeve (6) being sleeved on the outside of the lower joint (3) and fixedly connected to the lower joint (3), a piston (7) being arranged above the lower joint (3) between the cylinder sleeve (6) and the center tube (1), and a backwash valve (9) being arranged above the piston (7). ), the backwash sleeve (8) is sleeved on the outside of the backwash valve (9), the backwash sleeve (8) is fixedly connected to the cylinder sleeve (6), and the lower joint (3) is connected to the cylinder sleeve (6) via a control pin (10); a locking mechanism is provided above the outer rubber sleeve (5) of the central tube (1), and an unsealing mechanism is connected to the locking mechanism; a backwash channel (11) is provided between the cylinder sleeve (4) and the central tube (1); a backwash hole C (12) is provided on the side of the lock sleeve (16), and a backwash hole B (13) is provided on the side of the cylinder sleeve (4); the backwash hole C (12) and the backwash hole B (13) are connected to the backwash channel (11), and a backwash hole A (14) is provided on the side of the backwash sleeve (8).

2. A water injection packer according to claim 1, characterized in that: The number of the rubber cylinders (5) outside the cylinder sleeve (4) is no less than 2 groups, and a spacer ring (22) is provided between two adjacent groups of rubber cylinders (5).

3. A water injection packer according to claim 1, characterized in that: The locking mechanism comprises a locking ring (15) arranged above the rubber sleeve (5) outside the sleeve (4), the locking ring (15) being fixedly connected to the sleeve (4), a locking sleeve (16) being arranged above the locking ring (15), the top end of the locking sleeve (16) being fixedly connected to the upper joint (2), and an internal thread matching the external thread on the outer side of the locking ring (15) being arranged on the inner side surface of the locking sleeve (16).

4. A water injection packer according to claim 3, characterized in that: A seat sleeve (17) is connected between the locking ring (15) and the sleeve (4); the seat sleeve (17) and the sleeve (4) are connected via an unsealing mechanism; and the locking ring (15) and the seat sleeve (17) are connected via threads.

5. A water injection packer according to claim 4, characterized in that: The unsealing mechanism comprises an unsealing pin (18) connected between the seat sleeve (17) and the cylinder sleeve (4).

6. A water injection packer according to any one of claims 3 to 5, characterized in that: The bottom end of the locking sleeve (16) is connected to a retaining ring (19), the bottom end surface of the retaining ring (19) abuts against the top end surface of the rubber sleeve (5), and the retaining ring (19) is connected to the sleeve (4) in an upward and downward sliding manner.

7. A water injection packer according to claim 1, characterized in that: A spring (20) and a limiting sleeve (21) are provided between the lower joint (3) in the cylinder sleeve (6) and the piston (7).

8. A water injection packer according to claim 1, characterized in that: The top of the inner side surface of the backwash valve (9) is arranged in a step shape, and the inner step surface of the top of the backwash valve (9) is sleeved with the outer step surface of the bottom end of the sleeve (4), and an annular groove is formed between the backwash sleeve (8) and the step surface at the bottom of the sleeve (4), and a sealing gasket (23) is arranged in the annular groove.

Images