Full-bore multistage staged fracturing sliding sleeve

Abstract

The utility model provides a full-bore multistage staged fracturing sliding sleeve, which relates to the technical field of fracturing sliding sleeves and comprises an upper joint and a lower joint, a core sleeve is arranged in an inner cavity of the upper connector, a spacer sleeve is connected to the middle of the right end of the core sleeve and is locked through multiple sets of shear pins, the spacer sleeve is located in an inner cavity of the lower connector, and a limiting groove is formed in the middle of the inner side of the lower connector and is formed in the outer side of the spacer sleeve. A plurality of lock grooves are formed in the middle of the inner side of the core sleeve in the circumferential direction, a soluble key is arranged in an inner cavity of the core sleeve, a plurality of lock teeth are installed on the outer wall of the soluble key in the circumferential direction, and the lock teeth correspond to the lock grooves. The soluble key and the core sleeve are fixedly connected in a clamped mode through the lock teeth and the lock grooves, the soluble key is locked, then the soluble key drives the core sleeve to slide downwards through pressure pushing, the fracturing effect is achieved, after fracturing construction is completed, the soluble key is completely dissolved, and the soluble key is prevented from being damaged. And the condition of blockage cannot be worried about.

Description

Technical Field

[0001] This utility model relates to the field of fracturing sliding sleeve technology, specifically a full-bore multi-stage segmented fracturing sliding sleeve. Background Technology

[0002] Multistage fracturing is currently the main method for enhancing production in tight oil reservoirs. Specialized tools are required for staged fracturing; the main tools currently available include coiled tubing-driven fracturing tools, ball-drop fracturing tools, and infinite-stage fracturing sliding sleeve tools. Coiled tubing-driven fracturing requires coiled tubing equipment and involves perforating the casing via sandblasting, which is unsuitable for offshore platform operations. It also presents challenges in controlling perforation quality and has a long operation time. Fracturing technology is a key technology for developing low-permeability oil and gas reservoirs. After years of development, both domestic and international companies have established a series of fracturing technologies tailored to different reservoir types.

[0003] Currently, the main types of volumetric fracturing technology abroad are clustered sliding sleeves and composite bridge plugs. After fracturing is completed, ball seats or bridge plugs remain in the wellbore, which can easily cause blockage of oil and gas wells. The ball seats and bridge plugs need to be drilled out, which increases the operating cost.

[0004] To address the aforementioned issues, we propose a full-bore, multi-stage, segmented fracturing sleeve. Utility Model Content

[0005] To address the problems in the background art, this utility model provides a full-bore multi-stage segmented fracturing sleeve.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A full-bore multi-stage segmented fracturing sleeve includes an upper connector and a lower connector; a core sleeve is provided in the inner cavity of the upper connector, and a retaining sleeve is connected to the middle of the right end of the core sleeve and locked by multiple sets of shear pins; the retaining sleeve is located in the inner cavity of the lower connector, and a limiting groove is provided in the middle of the inner side of the lower connector, and the limiting groove is located on the outside of the retaining sleeve.

[0008] The inner center of the core sleeve is provided with multiple sets of locking grooves in a circumferential manner. A soluble key is provided in the inner cavity of the core sleeve. Multiple sets of locking teeth are installed in a circumferential manner on the outer wall of the soluble key. The locking teeth correspond to the locking grooves. Two sets of spring pieces are provided on the back of the locking teeth. The spring pieces are in close contact with the soluble key. Pressure sleeves are provided at both ends of the locking teeth. The pressure sleeves are fixedly installed on the outer wall of the soluble key and are used to limit the locking teeth.

[0009] Preferably, both ends of the soluble key are sealed with annular lip seals.

[0010] Preferably, the upper connector and the lower connector are threaded together and locked by multiple sets of locking pins.

[0011] Preferably, the right end of the upper connector is equipped with two sets of first seals, which are used to seal the connection between the upper connector and the lower connector.

[0012] Preferably, four sets of second seals are provided on the left side of the outer surface of the core sleeve, and the second seals are used to seal the connection between the core sleeve and the upper connector.

[0013] Preferably, an elastic retaining ring is provided on the right side of the outer surface of the core sleeve, and the elastic retaining ring is used to seal the connection between the core sleeve and the lower connector.

[0014] Preferably, the left end of the upper connector is provided with a liquid passage hole.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] In this solution, during use, the soluble key is inserted into the core sleeve, and then the locking teeth and lock groove are engaged and fixed to achieve a fixed connection between the soluble key and the core sleeve, thus locking the soluble key. At this time, by applying pressure inward, the soluble key pushes the core sleeve down, achieving a fracturing effect. Furthermore, after the fracturing operation is completed, the soluble key completely dissolves, so there is no concern about blockage. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the soluble key entering the slide groove in this utility model;

[0018] Figure 2 This is a schematic diagram of the structure of the sliding sleeve of this utility model when it is in the open position;

[0019] Figure 3 This is a schematic diagram of the structure of the core sleeve in this utility model;

[0020] Figure 4 This is a schematic diagram of the soluble key in this utility model.

[0021] In the diagram: 1. Upper connector; 11. Liquid passage hole; 12. Locking pin; 13. First seal; 2. Lower connector; 21. Limiting groove; 3. Core sleeve; 31. Second seal; 32. Lock groove; 33. Shear pin; 34. Elastic retaining ring; 4. Retaining sleeve; 5. Dissolved key; 51. Lip seal; 52. Pressure sleeve; 53. Locking tooth; 54. Spring. Detailed Implementation

[0022] The technical solution in this application embodiment is to solve the problems of the background technology mentioned above. The general idea is as follows: By setting a locking groove 32 in the core sleeve 3, multiple sets of locking teeth 53 are installed on the outer wall of the soluble key 5. The soluble key 5 is locked by engaging with the locking groove 32 through the locking teeth 53. Then, by applying pressure, the soluble key 5 will drive the core sleeve 3 to slide down under the pressure, thereby achieving the fracturing effect. After the fracturing operation is completed, the soluble key 5 can be completely dissolved, and there is no concern about blockage.

[0023] Example: Refer to Figure 1 - Figure 4 As shown, a full-bore multi-stage segmented fracturing sleeve of this embodiment includes an upper connector 1 and a lower connector 2; a core sleeve 3 is provided in the inner cavity of the upper connector 1, and a retaining sleeve 4 is connected to the middle of the right end of the core sleeve 3 and locked by multiple sets of shear pins 33. The retaining sleeve 4 is located in the inner cavity of the lower connector 2, and a limiting groove 21 is provided in the middle of the inner side of the lower connector 2. The limiting groove 21 is provided on the outer side of the retaining sleeve 4.

[0024] The inner side of the core sleeve 3 is provided with multiple sets of lock grooves 32 in a circumferential manner. The inner cavity of the core sleeve 3 is provided with a soluble key 5. The outer wall of the soluble key 5 is provided with multiple sets of lock teeth 53 in a circumferential manner. The lock teeth 53 correspond to the lock grooves 32. Two sets of spring pieces 54 are provided on the back of the lock teeth 53. The spring pieces 54 are in close contact with the soluble key 5. Both ends of the lock teeth 53 are provided with pressure sleeves 52. The pressure sleeves 52 are fixedly installed on the outer wall of the soluble key 5. The pressure sleeves 52 are used to limit the lock teeth 53.

[0025] Both ends of the soluble key 5 are sealed with annular lip seals 51, which serve to seal the connection between the soluble key 5 and the core sleeve 3.

[0026] The upper connector 1 and the lower connector 2 are connected by threads and locked by multiple sets of locking pins 12; two sets of first seals 13 are installed on the right end of the upper connector 1, which are used to seal the connection between the upper connector 1 and the lower connector 2.

[0027] In some examples, four sets of second seals 31 are provided on the left side of the outer surface of the core sleeve 3. The second seals 31 are used to seal the connection between the core sleeve 3 and the upper connector 1.

[0028] In some examples, an elastic retaining ring 34 is provided on the right side of the outer surface of the core sleeve 3. The elastic retaining ring 34 is used to seal the connection between the core sleeve 3 and the lower connector 2.

[0029] In some examples, the left end of the upper connector 1 is provided with a liquid passage 11.

[0030] In some examples, the metal parts of the soluble key 5 are made of soluble materials. After fracturing is completed, the blockage problem is effectively solved by completely dissolving the soluble key 5.

[0031] The working principle of this utility model is as follows:

[0032] When in use, first install this sliding sleeve on the well string, and then lower it into the target formation along with the well string. At this time, the sliding sleeve is in the closed state, that is, the fluid hole 11 is in the closed state.

[0033] By inserting a soluble key 5 at the wellhead, fracturing begins from the bottom fracturing sleeve. After the soluble key 5 enters the core sleeve 3, it compresses the spring 54 as it slides down until the locking tooth 53 slides down to the locking groove 32. At this point, the spring 54 loses its compressive force and rebounds, causing the locking tooth 53 to engage in the locking groove 32, thus achieving a fixed connection between the soluble key 5 and the core sleeve 3 and locking the soluble key 5. At this time, pressure is applied inward through the upper connector 1, and the pressure pushes the soluble key 5 to drive the core sleeve 3 down, achieving the fracturing effect. During the descent of the core sleeve 3, it will shear the shear pin 33 until the core sleeve 3 reaches the limiting groove 21 and is locked. At this time, the elastic retaining ring 34 will engage in the limiting groove 21 to seal the core sleeve 3.

[0034] After the above steps, the final state after the sliding sleeve fracturing is completed is as follows: after the layered fracturing operation is completed, all metal parts of the soluble key 5 will dissolve on their own, so that the inner diameter of all fracturing sliding sleeves is consistent, thus avoiding blockage.

[0035] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A full-gauge, multi-stage, segmented fracturing sleeve, characterized in that, The upper joint (1) and the lower joint (2) are provided. The inner cavity of the upper joint (1) is provided with a core sleeve (3), the right end of the core sleeve (3) is connected with a blocking sleeve (4), and the blocking sleeve (4) is located in the inner cavity of the lower joint (2). The inner side of the core sleeve (3) is provided with a plurality of locking grooves (32) in the middle part, and the inner cavity of the core sleeve (3) is provided with a soluble key (5). The outer wall of the soluble key (5) is provided with a plurality of lock teeth (53) in the circumferential direction, and the number and position of the lock teeth (53) correspond to the number and position of the locking grooves (32).

2. A full gauge multistage segmented frac sleeve according to claim 1, wherein, The back of the lock tooth (53) is provided with two elastic sheets (54), the elastic sheet (54) is in contact with the soluble key (5), and the two ends of the lock tooth (53) are provided with a pressing sleeve (52).

3. A full gauge multistage segmented frac sleeve according to claim 2, wherein, The both ends of the soluble key (5) are sealed and installed with annular lip seals (51).

4. A full gauge multistage segmented frac sleeve according to claim 3, wherein, The upper joint (1) and the lower joint (2) are threadedly connected and locked by a plurality of locking pins (12).

5. A full gauge, multi-stage, segmented frac sleeve according to claim 4, wherein, The right end of the upper joint (1) is provided with two first sealing elements (13), and the two first sealing elements (13) are used for sealing the connection between the upper joint (1) and the lower joint (2).

6. A full gauge, multi-stage, segmented frac sleeve according to claim 5, wherein, The left side of the outer surface of the core sleeve (3) is provided with four second sealing elements (31), and the second sealing elements (31) are used for sealing the connection between the core sleeve (3) and the upper joint (1).

7. A full gauge multistage segmented frac sleeve according to claim 6, wherein, The right side of the outer surface of the core sleeve (3) is provided with an elastic blocking ring (34), and the elastic blocking ring (34) is used for sealing the connection between the core sleeve (3) and the lower joint (2). The left end of the upper joint (1) is provided with a liquid passing hole (11).

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