Dissolving delay toe end sliding sleeve

Abstract

The utility model discloses a dissolution delay toe end sliding sleeve which comprises an upper connector, a lower connector and a shell and further comprises a supporting piece, a partition block is arranged on the supporting piece, the partition block is in clearance fit with the shell, a first fracturing hole is formed in the shell, a second fracturing hole is formed in the supporting piece, and a cavity is formed between the supporting piece and the shell. The cavity comprises a time delay cavity and an opening cavity, the time delay cavity is provided with a sliding part and a time delay agent container, the sliding part is provided with a time delay rubber ring and fixed to the side, close to the upper connector, of the time delay cavity through a time delay shear pin, the opening cavity is provided with an opening part, and the opening part is matched with a positioning shear pin to be fixed between the first fracturing hole and the second fracturing hole. The delay mechanism in the pressure test process is completed through the chemical reaction of the delay agent and the rubber ring, the fracturing hole is opened through sliding of the opening piece, the delay time can be accurately controlled, and the stability and convenience of pressure test operation and fracturing operation can be enhanced.

Description

Technical Field

[0001] This utility model belongs to the field of oil well engineering equipment, specifically relating to a dissolution delay toe end sliding sleeve. Background Technology

[0002] Coiled tubing perforation is used in horizontal well completion operations, typically employing toe-sleeve technology for the initial fracturing stage, providing a pump flow path for subsequent bridge plug perforation. Currently, when using toe-sleeve technology, a pressure test is required on the production casing connected to the toe-sleeve before fracturing. Therefore, to ensure stable pressure testing and fracturing operations, the toe-sleeve opening method is generally set to delayed opening. However, existing technologies use water-soluble metal delay rings to dissolve the sleeve for delayed opening. But soluble metals are susceptible to temperature variations related to water and mineralization, easily failing in dry environments and exacerbating corrosion at high temperatures. This can lead to inaccurate delay accuracy and incomplete sleeve dissolution, causing blockages and other adverse effects during operations. Furthermore, some technologies use a throttling method for delayed opening, which results in pressure drops during execution, potentially negatively impacting casing pressure test results and posing a risk of premature opening. The low delay tolerance also negatively affects the stability of the toe-sleeve operation.

[0003] Therefore, a more reliable way is needed to solve the above problems. Utility Model Content

[0004] This invention provides a dissolving delay toe sleeve to solve at least one of the above-mentioned technical problems.

[0005] The technical solution adopted in this utility model is as follows: a dissolving delay toe sleeve, including an upper connector, a lower connector, and a shell, and also including a support member. The support member is provided with a partition block, which is clearance-fitted with the shell. The shell is provided with a first fracturing hole, and the support member is provided with a second fracturing hole. A cavity is formed between the support member and the shell. The cavity is divided into a delay cavity and an opening cavity by the partition block. The delay cavity is provided with a sliding member and a delay agent container. The sliding member is provided with a delay rubber ring. The sliding member is fixed to the side of the delay cavity near the upper connector by a delay shear pin. The opening cavity is provided with an opening member, which is fixed between the first fracturing hole and the second fracturing hole in cooperation with a positioning shear pin.

[0006] Preferably, the delay agent container contains a delay solution that can react with the delay rubber ring.

[0007] Preferably, the portion of the support member intersecting the upper connector is provided with a flow hole.

[0008] Preferably, the upper connector and the lower connector are each provided with an O-ring.

[0009] Preferably, the sliding member is provided with a first sealing ring, the portion of the support member that overlaps with the sliding member is provided with a second sealing ring, and the opening member is provided with an O-ring.

[0010] Preferably, the O-ring, the first sealing ring, or the second sealing ring is made of fluororubber or polytetrafluoroethylene.

[0011] Preferably, the delay cavity is provided with a mounting groove for fixing the delay agent container.

[0012] Preferably, a silicone sheet is provided at the bottom of the mounting groove, and the delay agent container is fixed in the mounting groove by tape or adhesive.

[0013] Preferably, the sliding member is in clearance fit or transition fit with the housing, and the sliding member is in clearance fit or transition fit with the support member.

[0014] Preferably, the opening member is clearance-fitted or transition-fitted with the outer shell, and the opening member is clearance-fitted or transition-fitted with the support member.

[0015] Due to the adoption of the above technical solution, the beneficial effects achieved by this utility model are as follows:

[0016] 1. This utility model discloses a dissolving delay toe sleeve, comprising an upper connector, a lower connector, and a shell, and further comprising a support member. A partition block is provided on the support member, forming a chamber between the support member and the shell. The chamber is divided into a delay chamber and an opening chamber by the partition block. A gap exists between the partition block and the shell, allowing pressurized fluid to flow into the opening chamber through the gap. A sliding member and a delay agent container are provided in the delay chamber. A delay rubber ring is provided on the sliding member. The sliding member is fixed to the side of the delay chamber near the upper connector by delay shear pins. An opening member is provided in the opening chamber. The delay rubber ring is made of a material with excellent airtightness and low permeability, ensuring sealing before pressure testing and fracturing. In addition to its integrity, the delay ring has good corrosion resistance, which can prevent premature failure caused by complex fluid environments downhole, thereby reducing the risk of premature fracturing operations. The delay effect can be achieved through the cooperation between the various structures in the delay cavity, making the wellbore pressure testing process more convenient and faster. The delay accuracy can be easily controlled by adjusting the size and distance of the various structures in the delay cavity. The outer shell is provided with a first fracturing hole, and the support is provided with a second fracturing hole. The opening part seals the connection between the first and second fracturing holes. The displacement of the opening part connects the first and second fracturing holes, making the operation process faster, safer, and more efficient.

[0017] Due to the high pressure inside the casing, the casing may expand outwards. Using delayed shear pins to fix the sliding component allows the hydraulic pressure or cementing pressure inside the wellbore to act on the outside of the sliding component, partially offsetting the outward expansion and making the sliding component slide more smoothly, reducing the sliding impact caused by deformation. On the other hand, it prevents the sliding component from prematurely actuating under unexpected pressure, ensuring the integrity of the casing pressure test. By adjusting the shear pin material or diameter, the opening pressure threshold can be precisely set to match well condition requirements.

[0018] The positioning shear pins are used to fix the opening component. In addition to working together with the delay shear pins, they can also fix the relative position of the opening component and the outer shell. By accurately installing the positioning shear pins, the initial sealing of the opening component to the first and second fracturing holes is ensured.

[0019] 2. In a preferred embodiment of this utility model, a delay solution that can chemically react with the delay rubber ring is placed in the delay agent container. The delay solution can be an acidic solution or an alkaline solution. The thickness of the delay rubber ring can be controlled, or the chemical reaction time between the delay rubber ring and the delay solution can be controlled by changing the concentration or dosage of the acidic or alkaline solution, thereby accurately controlling the delay accuracy during the wellbore pressure test and making the pressure test results more accurate.

[0020] 3. In a preferred embodiment of this utility model, the support member intersecting with the upper connector is provided with a flow hole. The flow hole is the only path for pressure and liquid to connect the chamber and the pipe. It can effectively balance the pressure environment of the chamber and the pipe, provide reliable physical isolation conditions for the linkage of various components in the chamber, and prevent problems such as pressure drop interference and pipe deformation jamming. It can effectively avoid malfunction of the device and thus achieve precise control.

[0021] 4. In a preferred embodiment of this utility model, O-rings are provided on the upper and lower connectors respectively, which can effectively maintain the closed environment inside the sleeve and ensure stability during operation; a first sealing ring is provided on the left side of the sliding member, and a second sealing ring is provided on the support member that overlaps with the sliding member and is close to the flow hole, which can ensure the sealed environment inside the cavity, so that the sliding member is only subjected to the force on the left side, preventing the torsional pressure from disrupting the balance environment inside the cavity, causing changes in the internal structure or premature opening of the sliding member, affecting the final fracturing result and causing an increase in the delay tolerance rate.

[0022] In addition, the opening element is also equipped with an O-ring seal, which can ensure the sealing environment inside the opening element, effectively maintain the pressure balance between the opening element and the chamber in which the opening element is located, improve the stability of the opening element, and prevent the opening element from expanding and deforming due to pressure flowing into the opening element, thus preventing it from being displaced to open the fracturing hole and causing the fracturing operation to fail.

[0023] On the other hand, all types of sealing rings are made of fluororubber or polytetrafluoroethylene. Fluororubber has excellent oil resistance, heat resistance and chemical corrosion resistance, making it more suitable for use in harsh environments such as high temperature, high pressure and high speed in well pressure testing operations. Polytetrafluoroethylene also has good high temperature resistance and corrosion resistance. In addition, this material has an extremely low coefficient of friction and excellent insulation properties, and has good self-lubricating properties, which can effectively reduce the wear of the sealing surface.

[0024] 5. In a preferred embodiment of this utility model, an installation groove for fixing the delay agent container is provided in the delay cavity. The installation groove, through structural design (the groove size matches the delay agent container), fixes the delay agent container, which can prevent premature corrosion of the delay rubber ring due to leakage of solution in the delay agent container caused by collision, vibration or operational errors, thereby affecting the delay accuracy of the wellbore pressure test environment. Using glass test tubes or the like as containers can cooperate with the sliding parts to complete the impact, and release acidic liquid after breaking, ensuring that the reaction only starts under preset conditions, avoiding premature corrosion caused by the complex downhole environment. On the other hand, the test tubes made of glass or other materials are inert to acidic or alkaline solutions, and will not cause side reactions or corrosion, ensuring stable acid concentration, while preventing acidic liquid from contacting metal parts or other sealing rubber rings, preventing the overall delay structure from failing.

[0025] 6. In a preferred embodiment of this utility model, a silicone sheet is provided at the bottom of the mounting groove. The silicone sheet acts as an elastic sealing layer, filling the microscopic gaps between the delay agent container and the mounting groove. This prevents acidic or alkaline liquids from leaking due to vibration or pressure fluctuations before triggering. Furthermore, the elasticity of the silicone absorbs the impact of uncontrollable substances or pressure liquids on the glass test tube, acting as a buffer mechanism to reduce the risk of accidental breakage. The glass test tube is fixed in the mounting groove with tape or adhesive, preventing shaking during operation and avoiding premature breakage that could affect the delay mechanism.

[0026] 7. In a preferred embodiment of this utility model, the sliding component is fitted with the outer shell and the support component with a clearance fit or a transition fit, and the opening component is fitted with the outer shell and the support component with a clearance fit or a transition fit. The clearance fit allows for a small gap between the sliding component and the outer shell, ensuring rapid and low-resistance movement of the sliding component under high pressure. This avoids operational failure due to tube expansion or deformation, and also helps reduce stringent requirements for machining accuracy, improving tool tolerance. If a transition fit is used, adjusting the appropriate interference or clearance ensures the sliding component remains stable during the pressure testing phase (high-pressure static load) and moves smoothly during the fracturing phase (dynamic impact). Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:

[0028] Figure 1 This is a schematic cross-sectional view of the dissolution delay toe sleeve structure according to an embodiment of the present invention;

[0029] Figure 2 for Figure 1 A magnified view of a portion of region A in the middle;

[0030] Figure 3 for Figure 1 A magnified view of a portion of region B in the middle;

[0031] Figure 4 This is a schematic diagram of the partition block structure according to an embodiment of the present utility model;

[0032] Figure 5 This is a schematic diagram of the displacement state of the sliding member according to an embodiment of the present utility model;

[0033] Figure label:

[0034] 1. Connector;

[0035] 2. Lower connector;

[0036] 3. Outer shell;

[0037] 31. Delayed shear pin; 301. First fracturing hole;

[0038] 32. Positioning clips;

[0039] 4. Support components;

[0040] 41. Flow hole; 401. Second fracturing hole;

[0041] 42. Second sealing ring;

[0042] 43. Divider block;

[0043] 5. Chamber;

[0044] 51. Delay chamber; 510. Glass test tube; 511. First air chamber;

[0045] 52. Opening cavity; 521. Second air cavity;

[0046] 6. Sliding components;

[0047] 61. Delay rubber ring; 62. First sealing rubber ring;

[0048] 7. Opening component;

[0049] 8. Mounting slot;

[0050] 81. Silicone sheet;

[0051] 9. Container for delay agent;

[0052] 10. O-ring seal. Detailed Implementation

[0053] To more clearly illustrate the overall concept of this utility model, a detailed description will be provided below with reference to the accompanying drawings.

[0054] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0055] Furthermore, it should be understood in the description of this utility model that the terms "top", "bottom", "inner", "outer", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0056] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] In this invention, unless otherwise expressly specified and limited, the first feature "on" or "below" the second feature may be in direct contact with the first and second features, or indirect contact through an intermediate medium. In the description of this specification, references to terms such as "implementation," "example," "aspect," or "specific example" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0058] Example 1

[0059] like Figure 1 As shown, a dissolution delay toe sleeve includes an upper connector 1, a lower connector 2, and a housing 3. The upper connector 1 and the lower connector 2 are threadedly connected to the housing 3. Two O-rings 10 are provided on the upper connector 1, and four O-rings 10 are provided on the lower connector 2 to maintain a sealed environment. A support member 4 is also provided between the upper connector 1 and the lower connector 2. The upper end of the support member 4 abuts against the tail end of the upper connector 1, and the lower end of the support member 4 abuts against the tail end of the lower connector 2. In addition, a partition block 43 is provided on the support member 4, and the partition block 43 is fitted with the housing 3 with a gap. A first fracturing hole 301 is opened on the housing 3, and a second fracturing hole 401 is opened on the support member 4. The two fracturing holes are on the same vertical line and are interconnected.

[0060] The outer shell 3 and the support member 4 enclose the chamber 5. Furthermore, a flow hole 41 is formed on the support member 4, located close to the left side of the sliding member 6. Only the flow hole 41 connects the chamber 5 to the inside of the pipe, effectively balancing the pressure environment between the chamber 5 and the inside of the pipe, providing reliable physical isolation for the linkage of various components within the chamber 5. The chamber 5 is divided into two parts by a partition block 43: a delay chamber 51 and an opening chamber 52. A sliding member 6 is located on the left side of the delay chamber 51 and fixed by a delay shear pin 31. A delay rubber ring 61 is installed on the inner wall of the sliding member 6, effectively blocking pressure and liquid on the left side. Butyl rubber was chosen as the delay rubber ring 61. Butyl rubber is easily corroded by acidic liquids, causing the delay rubber ring 61 made of butyl rubber to gradually lose its sealing effect. The sliding member 6 has a clearance fit with the outer shell 3 and the support member 4. After the pressure shears off the delay shear pin 31, the sliding member 6 can slide within the delay chamber 51. A [missing information - likely a device or component] is fixed on the right side of the delay chamber 51. The delay agent container 9 contains an acidic solution that can react with the delay rubber ring 61. After the reaction is completed, the pressure and liquid flow into the opening chamber 52 through the gap between the baffle block 43 and the outer shell 3. Inside the opening chamber 52, an opening element 7 is fixed by a positioning shear pin 32. The opening element 7 separates the first fracturing hole 301 and the second fracturing hole 401. The opening element 7 is clearance-fitted with the outer shell 3 and the support 4. After the pressure shears off the positioning shear pin 32, the opening element 7 can slide in the opening chamber 52, thereby opening the fracturing hole. Fracturing can be completed through the cooperation of the various structures in the chamber 5, making the wellbore pressure test process more convenient and faster.

[0061] Example 2

[0062] like Figure 2 , Figure 3As shown, a dissolving delay toe-end sliding sleeve, different from Embodiment 1, has multiple first sealing rings 62 on the outer wall of the sliding member 6, and two second sealing rings 42 sequentially arranged on the outer wall of the support member 4 near the flow hole 41. This ensures a sealed environment within the delay cavity 51, preventing pressure from disrupting the balance environment within the delay cavity 51, causing changes in the structures within the delay cavity 51, or prematurely opening the sliding member 6. The sliding member 6 has a first air cavity 511 on its right side, allowing the sliding member 6 to slide to the right along the first air cavity 511. By controlling the size of the first air cavity 511, the movement of the sliding member 6 relative to the glass test tube 5 can be controlled. The collision time is controlled to limit the time it takes for the delay ring 61 to become corroded and fail due to the acidic solution. In addition, a glass test tube 510 is used as the delay agent container 9, which facilitates the impact with the sliding member 6 and is also beneficial for holding acidic liquids. An installation groove 8 is set on the right side of the delay cavity 51 to better fix the glass test tube 510 and avoid leakage of the solution in the glass test tube 510 due to collision, vibration or operation error. A silicone sheet 81 is set at the bottom of the installation groove 8. The elasticity of the silicone sheet 81 can absorb the impact force when the sliding member 6 hits the glass test tube 510, and as a buffer mechanism, it reduces the risk of accidental breakage of the test tube.

[0063] Four O-rings 10 are respectively installed on the outer wall of the opening element 7 that overlaps with the outer shell 3 and on the inner wall of the opening element 7 that overlaps with the support 4 to enhance the sealing effect of the opening element 7. The four O-rings 10 on the left outer and inner walls can effectively keep the pressure fluid on the left side, effectively preventing pressure and liquid from flowing into the opening element 7 due to improper sealing. This would prevent the pressure and liquid from shearing the positioning pin 32, causing the opening element 7 to move through the first fracturing hole 301 and the second fracturing hole 401, affecting the wellbore pressure test results. It is worth noting that the opening cavity 52 contains the opening element 7 and the second air cavity 521. The second air cavity 521 is on the right side of the opening element 7. The four O-rings 10 on the right outer and inner walls can prevent pressure fluid from entering the second air cavity 521, preventing the opening element 7 from being unable to move to the right. The opening element 7 can slide to the right along the second air cavity 521 to open the fracturing hole. By controlling the size of the second air cavity 521, the size of the fracturing hole opened by the opening element 7 can be controlled, thereby controlling the fracturing depth.

[0064] Example 3

[0065] like Figure 4As shown, in a dissolving delay toe sleeve, the sliding member 6 moves in a certain state. During the full wellbore pressure test, when the pressure is set to 85MPa, the liquid and pressure inside the tube will enter the delay chamber 51 through the flow hole 41. At this time, under the strong pressure, the delay shear pin 31 is shortened and pushes the sliding member 6 to move to the right along the first air chamber 511. After moving a certain distance, the second sealing ring 42 on the support member 4 will release the seal. The liquid and pressure inside the tube will be blocked on the left side of the sliding member 6 by the delay ring 61. At this time, the sliding member 6 hits the glass test tube 510 in the mounting groove 8. After the glass test tube 510 breaks, the acidic solution reacts with the delay ring 61 on the inner wall of the sliding member 6. After the reaction is completed, the delay ring 61 will lose its sealing effect. The liquid and pressure inside the tube will pass through the sliding member 6 and be transmitted to the opening member 7 through the gap between the partition block 43 and the outer shell 3.

[0066] For any parts not mentioned in this utility model, existing technologies can be used or referenced.

[0067] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0068] The above description is merely an embodiment of this utility model and is not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this utility model should be included within the scope of the claims of this utility model.

Claims

1. A dissolving delay toe sleeve comprising an upper sub (1), a lower sub (2) and a housing (3), characterized in that, Also include support (4), the support (4) is equipped with a barrier block (43), the barrier block (43) and the shell (3) gap fit, the shell (3) is equipped with a first fracturing hole (301), the support (4) is equipped with a second fracturing hole (401), the support (4) and the shell (3) form a cavity (5) between them, the cavity (5) is divided into delay chamber (51) and opening chamber (52) by the barrier block (43), the delay chamber (51) is equipped with a sliding member (6) and a delay agent container (9), the sliding member (6) is equipped with a delay rubber ring (61), the sliding member (6) is fixed in the delay chamber (51) by a delay shear pin (31) near the upper joint (1) side, the opening chamber (52) is equipped with an opening member (7), the opening member (7) is fixed between the first fracturing hole (301) and the second fracturing hole (401) by cooperating with a positioning shear pin (32).

2. A dissolving delay toe slip according to claim 1, wherein, The delay agent container (9) contains a delay solution that can react with the delay rubber ring (61).

3. The dissolving delay toe slip according to claim 1, wherein, The part of the support (4) intersecting the upper joint (1) is provided with an overflow hole (41).

4. The dissolving delay toe slip according to claim 1, wherein, The upper joint (1) and the lower joint (2) are respectively provided with an O-shaped sealing rubber ring (10).

5. A dissolving delay toe slip according to claim 4, wherein, The sliding member (6) is provided with a first sealing rubber ring (62), and the part of the support (4) coinciding with the sliding member (6) is correspondingly provided with a second sealing rubber ring (42), and the opening member (7) is provided with an O-shaped sealing rubber ring (10).

6. A dissolving delay toe slip according to claim 5, wherein, The material of the O-shaped sealing rubber ring (10), the first sealing rubber ring (62) or the second sealing rubber ring (42) is fluorine rubber or polytetrafluoroethylene.

7. The dissolving delay toe slip according to claim 1, wherein, The delay chamber (51) is provided with a mounting groove (8) for fixing the delay agent container (9), and the delay agent container (9) is a glass test tube (510).

8. A dissolving delay toe slip in accordance with claim 7, wherein, The bottom end of the mounting groove (8) is provided with a silica gel sheet (81), and the delay agent container (9) is fixed in the mounting groove (8) by adhesive tape or adhesive.

9. The dissolving delay toe slip according to claim 1, wherein, The sliding member (6) and the shell (3) gap fit or transition fit, the sliding member (6) and the support (4) gap fit or transition fit.

10. The dissolving delay toe slip according to claim 1, wherein, The opening member (7) and the shell (3) gap fit or transition fit, the opening member (7) and the support (4) gap fit or transition fit.

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