Small-diameter separated layer water injection packer

Abstract

A small-diameter separated layer water injection packer relates to the field of oil field downhole tools and comprises a central tube, a liner tube, a rubber sleeve and a piston, a well washing channel is reserved between the central tube and the liner tube, the rubber sleeve is sleeved on the outer side of the liner tube, the piston is slidably mounted on the outer side of the central tube, a setting push sleeve is arranged above the piston, and the upper end of the setting push sleeve is slidably matched with the outer wall of the liner tube. The inner wall of the lower end of the setting push sleeve is in sliding sealing fit with the outer wall of the piston; a sealing sleeve is fixedly connected to the outer side of the lower end of the piston, a sealing slip ring is arranged in an annular space between the sealing sleeve and the central pipe, and the inner and outer sides of the sealing slip ring are in sliding sealing fit with the sealing sleeve and the central pipe respectively; a liquid passing hole corresponding to the lower end face of the piston is machined in the pipe wall of the center pipe. According to the utility model, the structure of the packer is greatly simplified, so that the diameter of the packer is smaller, the length of the packer is shorter, the structure is greatly simplified, the manufacturing cost is greatly reduced, and the working reliability is remarkably improved.

Description

Technical Field

[0001] The utility model belongs to the field of oil field downhole tools, in particular to a small-diameter stratified water injection packer. Background Art

[0002] The flushable well packer is a downhole tool commonly used in oilfield water injection technology. The flushable well packer is provided with a well flushing piston and a setting piston, which are used to realize the well flushing function and the setting function respectively.

[0003] In the prior art, the well-washing piston and the setting piston are respectively arranged at the upper and lower parts of the packer. This structure has the following shortcomings: 1. The diameter of the packer is too large to be directly used in small-diameter wells. After the existing packer is proportionally reduced, the diameter can meet the requirements of small-diameter wells; 2. The structure is complex and the manufacturing cost is high; 3. The length is too large, which is not conducive to construction operations.

[0004] Therefore, it is necessary to optimize the existing technology to solve the above problems. Utility Model Content

[0005] The utility model provides a small-diameter layered water injection packer, which aims to optimize the structure of the existing packer to make the diameter and length smaller and the structure simpler.

[0006] The technical problem solved by the present invention is achieved by adopting the following technical solution: The present invention provides a small-diameter stratified water injection packer, comprising a central pipe, a liner, a rubber cylinder and a piston, a well washing channel being left between the central pipe and the liner, and the rubber cylinder being sleeved on the outside of the liner;

[0007] The piston is slidably mounted on the outside of the central tube, and a setting sleeve is provided above the piston. The upper end of the setting sleeve is in sliding cooperation with the outer wall of the liner, and the inner wall of the lower end of the setting sleeve is in sliding and sealing cooperation with the outer wall of the piston.

[0008] A sealing sleeve is fixedly connected to the outer side of the lower end of the piston, and a sealing slip ring is provided in the annular space between the sealing sleeve and the central tube. The inner and outer sides of the sealing slip ring respectively slide and seal with the sealing sleeve and the central tube;

[0009] A liquid hole corresponding to the lower end surface of the piston is processed on the wall of the central tube.

[0010] As a preferred solution, the lower end of the piston is inserted into the inner side of the upper end of the sealing slip ring and is fixedly connected by a setting pin.

[0011] As a preferred solution, a radial through hole is processed at the lower end of the piston, a radially sliding locking block is installed in the radial through hole, a locking groove corresponding to the locking block is processed on the outer side of the center tube, one end of the locking block is inserted in the locking groove, and the other end of the locking block is against the inner wall of the sealing slip ring.

[0012] As a preferred solution, a sealing ring made of soft material is provided on the outer side of the upper end of the piston, and a sealing fit is achieved between the piston and the setting sleeve through the sealing ring.

[0013] As a preferred solution, a retaining spring hanger is provided at the lower end of the liner, and the retaining spring hanger is fixedly connected to the liner through an unsealing pin. An annular groove is processed on the outer side of the retaining spring hanger, and a C-shaped retaining spring is installed in the annular groove. The outer surface of the C-shaped retaining spring and the inner surface of the sealing sleeve are respectively provided with ratchets that cooperate with each other.

[0014] As a preferred solution, an annular groove is processed on the outer side of the lower end of the center tube, and a wire retaining spring is installed in the annular groove, and the wire retaining spring protrudes from the outer surface of the center tube; the wire retaining spring is located at the connection between the piston and the sealing slip ring, thereby limiting the axial movement of the piston and the sealing slip ring.

[0015] The beneficial effects of the utility model are:

[0016] The utility model optimizes the structure of the existing packer, especially combines the well flushing piston and the setting piston in the prior art into one, and can realize both the setting and well flushing actions by controlling the action of one piston, thereby greatly simplifying the structure of the packer, making the diameter of the packer smaller, the length shorter, the structure greatly simplified, the manufacturing cost greatly reduced, and the working reliability significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0018] Figure 2 This is a partial enlarged view of the connection between the piston and the sealing slip ring.

[0019] In the figure: 1. Center pipe; 2. Liner; 3. Rubber cylinder; 4. Well washing channel; 5. Setting sleeve; 6. Unsealing pin; 7. C-type retaining ring; 8. Retaining ring hanger; 9. Ratchet; 10. Sealing ring; 11. Piston; 12. Liquid hole; 13. Locking block; 14. Setting pin; 15. Sealing slip ring; 16. Wire retaining ring.

[0020] In the figure, the black filled blocks located at the mating parts are O-rings. DETAILED DESCRIPTION

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] like Figure 1As shown, this embodiment includes a center pipe 1, a liner 2, a rubber sleeve 3, and a piston 11. A well-washing channel 4 is provided between the center pipe 1 and the liner 2. The rubber sleeve 3 is sleeved onto the outside of the liner 2. During setting, an external force drives the piston 11 to slide axially along the center pipe 1, thereby directly or indirectly pushing the end surface of the rubber sleeve 3, increasing its diameter and achieving setting. The above is a conventional structure in the prior art and will not be further described here.

[0023] like Figure 1 、 2 As shown, in this embodiment, the piston 11 is slidably mounted on the outside of the central tube 1. A sealing sleeve 5 is provided above the piston 11 for pushing the rubber cylinder 3 to achieve sealing. The upper end of the sealing sleeve 5 slides with the outer wall of the liner 2, and the inner wall of the lower end of the sealing sleeve 5 slides and seals with the outer wall of the piston 11. A sealing sleeve is fixedly connected to the outer side of the lower end of the piston 11. A sealing ring 15 is provided in the annular space between the sealing sleeve and the central tube 1 to seal the space below the piston 11. The inner and outer sides of the sealing ring 15 slide and seal with the sealing sleeve and the central tube 1, respectively. A liquid hole 12 corresponding to the lower end surface of the piston 11 is machined on the wall of the central tube 1 to transmit the pressure in the central tube 1 to the bottom of the piston 11.

[0024] like Figure 1 、 2 As shown, in this embodiment, the lower end of the piston 11 is inserted into the inner side of the upper end of the sealing ring 15 and is fixedly connected by the setting pin 14. During setting, when the setting pin 14 is cut off, the pressure is released instantly, thereby maximizing the thrust on the rubber cylinder 3.

[0025] like Figure 1 、 2 As shown, in this embodiment, a radial through-hole is machined into the lower end of the piston 11, in which a radially sliding locking block 13 is mounted. A locking groove corresponding to the locking block 13 is machined into the outer side of the center tube 1. One end of the locking block 13 is inserted into the locking groove, and the other end of the locking block 13 abuts against the inner wall of the sealing slip ring 15. Before setting, the locking block 13 is inserted into the locking groove under the limiting action of the sealing slip ring 15, thereby locking the piston 11 to the center tube 1. After setting, the sealing slip ring 15 disengages from the piston 11, releasing the limiting action of the sealing slip ring 15 on the locking block 13, allowing the locking block 13 to move radially and disengage the locking groove, thereby releasing the lock between the piston 11 and the center tube 1.

[0026] like Figure 1 、 2 As shown, in this embodiment, a sealing ring 10 made of soft material (conventional soft sealing materials such as polyurethane, fluororubber, nitrile rubber, etc.) is provided on the outer side of the upper end of the piston 11, and the sealing ring 10 is used to achieve sealing cooperation between the piston 11 and the setting sleeve 5.

[0027] like Figure 1 As shown, in this embodiment, a retaining spring hanger 8 is provided at the lower end of the liner 2, and the retaining spring hanger 8 is fixedly connected to the liner 2 through an unsealing pin 6. An annular groove is processed on the outer side of the retaining spring hanger 8, and a C-type retaining spring 7 is installed in the annular groove. The outer surface of the C-type retaining spring 7 and the inner surface of the sealing push sleeve 5 are respectively provided with ratchet teeth 9 that cooperate with each other.

[0028] like Figure 1 、 2 As shown, in this embodiment, an annular groove is processed on the outer side of the lower end of the center tube 1, and a wire retaining spring 16 is installed in the annular groove. The wire retaining spring 16 protrudes from the outer surface of the center tube 1; the wire retaining spring 16 is located at the connection between the piston 11 and the sealing slip ring 15, thereby limiting the axial movement of the piston 11 and the sealing slip ring 15.

[0029] Working principle:

[0030] During setting, high-pressure water is injected into the central tube 1, and the pressure is transmitted to the gap between the piston 11 and the sealing sliding ring 15 through the liquid hole 12, and then the piston 11 and the sealing sliding ring 15 are pushed to slide in opposite directions, thereby shearing the setting pin 14; after the setting pin 14 is sheared, under the action of pressure, the piston 11, the setting push sleeve 5 and the sealing sleeve slide upward, and after sliding: first, the rubber cylinder 3 is compressed by the setting push sleeve 5 to achieve setting; second, the sealing ring 10 on the outside of the piston 11 is on the inside of the setting push sleeve 5, thereby keeping the well washing channel 4 closed; third, under the action of the ratchet 9, the setting push sleeve 5 is locked by the C-shaped retaining spring 7 and cannot retreat, so that the rubber cylinder 3 can still maintain the setting state after the pressure in the central tube 1 is released.

[0031] When washing the well, the washing fluid is injected from the outside of the packer. The washing fluid enters the packer through the inlet at the upper end of the washing channel 4 and then enters the washing channel 4, and then pushes the piston 11 downward to release the seal between the piston 11 and the setting sleeve 5, so that the washing fluid can return to the outside of the packer again.

Claims

1. A small-diameter stratified water injection packer, comprising a central tube (1), a liner (2), a rubber cylinder (3) and a piston (11), wherein a well-washing passage (4) is left between the central tube (1) and the liner (2), and the rubber cylinder (3) is sleeved on the outside of the liner (2), characterized in that: The piston (11) is slidably mounted on the outside of the central tube (1), and a setting sleeve (5) is provided above the piston (11). The upper end of the setting sleeve (5) is slidably engaged with the outer wall of the liner (2), and the inner wall of the lower end of the setting sleeve (5) is slidably and sealingly engaged with the outer wall of the piston (11); A sealing sleeve is fixedly connected to the outer side of the lower end of the piston (11), and a sealing slip ring (15) is provided in the annular space between the sealing sleeve and the central tube (1). The inner and outer sides of the sealing slip ring (15) respectively slide and seal with the sealing sleeve and the central tube (1); A liquid hole (12) corresponding to the lower end surface of the piston (11) is processed on the wall of the central tube (1).

2. A small-diameter stratified water injection packer according to claim 1, characterized in that: The lower end of the piston (11) is inserted into the inner side of the upper end of the sealing slip ring (15) and is fixedly connected via a setting pin (14).

3. The small-diameter stratified water injection packer according to claim 2, characterized in that: The lower end of the piston (11) is processed with a radial through hole, and a radially sliding locking block (13) is installed in the radial through hole. The outer side of the central tube (1) is processed with a locking groove corresponding to the locking block (13), one end of the locking block (13) is inserted into the locking groove, and the other end of the locking block (13) is against the inner wall of the sealing slip ring (15).

4. The small-diameter stratified water injection packer according to claim 1, characterized in that: A sealing ring (10) made of a soft material is provided on the outer side of the upper end of the piston (11), and a sealing fit is achieved between the piston (11) and the setting sleeve (5) through the sealing ring (10).

5. The small-diameter stratified water injection packer according to claim 1, characterized in that: A retaining spring hanger (8) is provided at the lower end of the liner (2), and the retaining spring hanger (8) is fixedly connected to the liner (2) through an unsealing pin (6). An annular groove is processed on the outer side of the retaining spring hanger (8), and a C-shaped retaining spring (7) is installed in the annular groove. The outer surface of the C-shaped retaining spring (7) and the inner surface of the setting sleeve (5) are respectively provided with ratchet teeth (9) that cooperate with each other.

6. A small-diameter stratified water injection packer according to any one of claims 1 to 5, characterized in that: An annular groove is machined on the outer side of the lower end of the center tube (1), and a wire retaining spring (16) is installed in the annular groove. The wire retaining spring (16) protrudes from the outer surface of the center tube (1); the wire retaining spring (16) is located at the connection between the piston (11) and the sealing slip ring (15), thereby limiting the axial movement of the piston (11) and the sealing slip ring (15).

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