A detachable soluble bridge plug

Abstract

The present invention relates to a soluble bridge plug that prevents shedding, belonging to the technical field of soluble bridge plugs. The main body mechanism of the present invention is provided with an inner and an outer layer. The central tube has an ordinary dissolution rate and does not affect the conduction of the casing after subsequent dissolution. Moreover, the outer tube and the components installed thereon are all subjected to laser shock strengthening, having high temperature and high salt resistance performance, so that it will not dissolve prematurely within the predetermined construction time. Since the bridge plug adopts a double-layer structure, the outer layer is difficult to be dissolved and damaged, avoiding the situation that the device falls off the casing before the predetermined construction time and enhancing the stability of the device. When the predetermined plugging time is not reached, after the dissolution liquid enters the central tube through the gap between the ball and the ball seat to generate a gap, the metal seal in the sealing mechanism will adaptively deform under a certain pressure to seal the gap, avoiding the situation that more dissolution liquid enters the outside of the central tube through the gap to dissolve the two sides of the central tube simultaneously.

Description

Technical Field

[0001] The present invention relates to the technical field of soluble bridge plugs, and particularly to a soluble bridge plug that prevents falling off. Background Art

[0002] In oilfield exploration and development, when performing operations such as layered fracturing, layered acidizing, and layered well testing on oil and water wells, it is necessary to block the lower well section. A bridge plug is a commonly used safe, reliable, and low-cost downhole plugging tool in oil development. A soluble bridge plug is used for temporarily plugging layers such as oil, gas, water, and leakage, and can perform high-pressure fracturing operations on the producing formations above the soluble bridge plug. After the fracturing operation is completed, the bridge plug automatically dissolves under the conditions of well fluid and temperature in the well, providing a full passage for the production casing. Currently, this tool is mainly applied to the formation transformation of shale gas wells.

[0003] The patent with the publication number CN221722764U discloses a ball-throwing type double slip long rubber barrel soluble bridge plug for fracturing. When this prior art is subjected to extrusion pressure, the slip cone 1, the slip cone 2, and the elliptical rubber barrel will all expand outwards to form multiple layers of seals, achieving the effect of increasing the sealing performance. Moreover, during the process of the double slips expanding, self-centering occurs instantaneously, the setting shape is more centered, and the setting radius is large, adapting to various harsh conditions.

[0004] However, the above prior art has the following technical defects:

[0005] First, during the dissolution process, the ball dissolves first, and then the central tube dissolves. However, the ball shrinks during dissolution, resulting in dissolution liquid passing through the gap between the ball and the reduced-diameter cavity and entering the central tube. After the dissolution liquid contacts the inner wall of the central tube and causes it to dissolve to form a gap, more and more dissolution liquid enters the outside of the central tube through the gap, realizing two-sided dissolution of the central tube, accelerating the dissolution of the central tube, reducing the blockage time of the device, and resulting in the situation that the device dissolves in advance before reaching the blockage time.

[0006] Second, in order to achieve the dissolution speed of the device, the corrosion resistance and wear resistance of the internal structure of the device are poor. This will lead to low strength of the external slips and the nail teeth. After the structure contacts the dissolution liquid for a period of time, the components in contact with the inner wall of the casing will dissolve, causing the device to be released from the inner wall of the casing and resulting in the situation that the bridge plug falls off and the plugging fails.

[0007] In summary, there is still room for improvement in the prior art in terms of improving the fixing effect between the bridge plug and the inner wall of the casing and avoiding premature dissolution of the device. Therefore, those skilled in the art have proposed a device that can improve the fixing effect between the bridge plug and the inner wall of the casing and avoid premature dissolution of the device. Summary of the Invention

[0008] In order to solve the above problems, the present application provides a soluble bridge plug that prevents falling off, and adopts the following technical solutions:

[0009] It includes a main body mechanism. The main body mechanism includes a central tube. An outer tube with the same center is sleeved outside the central tube. Sealing plates are arranged between the head and tail ends of both the central tube and the outer tube. Two groups of slips and a soluble rubber ring are arranged outside the outer tube.

[0010] A sealing mechanism is arranged between the central tube and the outer tube. The sealing mechanism includes a plurality of main partition plates evenly distributed along the axial direction of the central tube. A plurality of secondary partition plates evenly distributed circumferentially around the central tube are arranged between the sealing plate and the adjacent main partition plate and between two adjacent main partition plates. The sealing plate cooperates with the main partition plate and the secondary partition plate to divide the space between the central tube and the outer tube into a plurality of sub - cavities.

[0011] A curved plate is arranged in each sub - cavity. The curved plate divides the sub - cavity into a main chamber and a secondary chamber. Through holes are formed on the side surface of the curved plate. A metal seal is arranged in the main chamber close to the curved plate. A sealing spring in a compressed state is installed on the side surface of the metal seal. The pressure in the main chamber is greater than that in the secondary chamber.

[0012] Preferably, a sliding tube adapted to it is sleeved inside each group of slips on the outer tube.

[0013] Preferably, an empty groove is formed on the side surface of the slip. An arc - shaped plate adapted to it is slidably arranged in the empty groove. A connecting rod connected to the corresponding sliding tube is installed at the center of the side surface of the arc - shaped plate.

[0014] Preferably, a ring groove is formed on the side surface of each group of slips. A rubber ring is arranged in all the ring grooves of each group together.

[0015] Preferably, a stress tube and a fixed tube are respectively slidably arranged on the side surfaces of the two sliding tubes. The fixed tube is fixedly connected to the outer tube. Pressure rings adapted to the inclined surfaces of the slips are installed on the side surfaces of both the stress tube and the fixed tube.

[0016] Preferably, a fixing ring is installed on the side surface of the outer tube near the stress tube. A fixing groove is formed on the side surface of the fixing ring. A rubber ring adapted to the fixing groove is installed on the other side surface of the stress tube.

[0017] Preferably, it further includes a fixing mechanism. The fixing mechanism includes a plurality of cross - plates evenly distributed between the central tube and the outer tube and passing through all the main partition plates. Rectangular grooves are formed on the side surfaces of the cross - plates in each sub - cavity.

[0018] Preferably, the end of the cross - plate extends outside the sealing plate and a Z - shaped plate is installed. The ends of all the Z - shaped plates are jointly installed with a stress ring. A return spring is connected between the side surface of the Z - shaped plate and the sealing plate.

[0019] Preferably, an extension rod passing through the corresponding rectangular groove in the sub - cavity is installed on the side surface of the metal seal. A limit block adapted to the rectangular groove is installed at the end of the extension rod.

[0020] In summary, the present application includes at least one of the following beneficial technical effects:

[0021] First, the main body mechanism of the present invention is provided with two layers, an inner and an outer layer. The central tube has a normal dissolution rate and does not affect the conduction of the casing after subsequent dissolution. Moreover, the outer tube and the components installed thereon are all subjected to laser shock peening and have high-temperature and high-salt resistance properties, making them less likely to dissolve. Thus, they will not dissolve prematurely within the predetermined construction time, avoiding the occurrence of ineffective sealing. When the slips and the studs are anchored to the inner wall of the casing, since the bridge plug adopts a double-layer structure, the outer layer is difficult to be dissolved and damaged, preventing the device from falling off the casing before the predetermined time and enhancing the stability of the device.

[0022] Second, through the cooperation of the main body mechanism and the sealing mechanism in the present invention, when the predetermined plugging time is not reached, after the dissolution liquid enters the central tube through the gap between the ball and the ball seat and creates a gap, the metal seal in the sealing mechanism will adaptively deform under a certain pressure to seal the gap, preventing more dissolution liquid from entering the outside of the central tube through the gap and dissolving both sides of the central tube simultaneously, avoiding premature dissolution of the device before the plugging time and improving the plugging effect of the device.

[0023] Third, in the present invention, a rubber ring is provided on the outside of each set of slips in the main body mechanism. The rubber ring can be used to limit the movement of the slips. Before the expandable rubber ring expands, it prevents the slips from moving and allows the studs to be anchored on the inner wall of the casing, thereby enabling the expandable rubber ring to be fully attached to the inner wall of the casing and improving the plugging effect. When the expandable rubber ring has completed expansion, continued pressurization can cause the rubber ring to break and the slips to move, allowing the studs to be anchored on the inner wall of the casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the drawings and embodiments.

[0025] Figure 1 is a schematic structural view of the present invention.

[0026] Figure 2 is a side view of the present invention.

[0027] Figure 3 is a schematic structural view of the main body mechanism of the present invention.

[0028] Figure 4 is a schematic structural view of the slips in the open state of the main body mechanism of the present invention.

[0029] Figure 5 is a schematic internal structure view of the present invention.

[0030] Figure 6 is a schematic structural view of the sealing mechanism of the present invention.

[0031] Figure 7It is a cross-sectional view of the sealing mechanism of the present invention.

[0032] Figure 8 It is a schematic structural diagram of the fixing mechanism of the present invention.

[0033] Figure 9 It is a cross-sectional view of the fixing mechanism of the present invention.

[0034] In the figure: 1. Main body mechanism; 101. Central tube; 102. Outer tube; 103. Sealing plate; 104. Slide tube; 105. Slip joint; 106. Empty groove; 107. Arc plate; 108. Connecting rod; 109. Tooth nail; 110. Ring groove; 111. Rubber ring; 112. Soluble rubber ring; 113. Pressure ring; 114. Stress tube; 115. Fixed tube; 116. Pressure ring; 117. Fixed ring; 118. Fixed groove; 119. Rubber ring; 120. Ball seat; 2. Sealing mechanism; 201. Main partition board; 202. Sub partition board; 203. Curved plate; 204. Metal seal; 205. Through hole; 206. Sealing spring; 207. Extension rod; 208. Limit block; 3. Fixing mechanism; 301. Horizontal board; 302. Rectangular groove; 303. Z-shaped board; 304. Stress ring; 305. Return spring. Detailed implementation manners

[0035] The following combines Figure 1 - Figure 9 to describe the embodiments of the present invention in detail.

[0036] The embodiment of the present application discloses a detachable soluble bridge plug. The main body mechanism and the sealing mechanism cooperate. When the predetermined plugging time is not reached, the dissolution liquid enters the central tube through the gap between the ball and the ball seat to create a gap, and then the gap will be blocked by the metal seal in the sealing mechanism, preventing more dissolution liquid from entering the outside of the central tube through the gap and dissolving both sides of the central tube simultaneously, avoiding premature dissolution of the device before the plugging time is reached, and improving the plugging effect of the device.

[0037] Embodiment 1:

[0038] As Figures 1-3 shown, it includes a main body mechanism 1. The main body mechanism 1 includes a central tube 101. An outer tube 102 concentric with it is sleeved outside the central tube 101. Sealing plates 103 are arranged between the head and tail ends of the central tube 101 and the outer tube 102. A ball seat 120 is installed at the end of the central tube 101. The outer tube 102 and the sealing plate 103 are used to protect the central tube 101. At the same time, the ball seat 120 is used to receive the plugging ball. The ball seat 120 adopts a conical design, which can allow the plugging ball to enter the ball seat 120 better for plugging.

[0039] As Figures 2-4As shown, two groups of slips 105 are symmetrically arranged on the outer side of the outer tube 102. A plurality of evenly distributed stud bolts 109 are installed on the outer side surface of the slips 105. During use, each group of slips 105 is expanded outwards until the stud bolts 109 are anchored on the inner wall of the casing.

[0040] As Figure 2 and Figure 3 shown, a soluble rubber ring 112 is arranged between the two groups of slips 105 on the outer tube 102. Pressure rings 113 are sleeved on both the head and the tail ends of the soluble rubber ring 112 on the outer tube 102. By squeezing the soluble rubber ring 112 with the two pressure rings 113, the soluble rubber ring 112 will expand in the squeezed state, so as to fit with the inner wall of the casing and achieve sealing and plugging.

[0041] As Figure 3 and Figure 4 shown, a sliding tube 104 adapted to each group of slips 105 is sleeved on the inner side of each group of slips 105 on the outer tube 102. An empty groove 106 is formed on the side surface of the slip 105. An arc-shaped plate 107 adapted to the empty groove 106 is slidably arranged in the empty groove 106. A connecting rod 108 connected to the corresponding sliding tube 104 is installed at the center of the side surface of the arc-shaped plate 107. When pressure is applied to the inclined surface of the slip 105, the slip 105 will move away from the sliding tube 104. Since the connecting rod 108 limits the arc-shaped plate 107, the arc-shaped plate 107 will move in the empty groove 106 during the movement of the slip 105.

[0042] As Figure 3 and Figure 4 shown, a ring groove 110 is formed on the side surface of each group of slips 105. A rubber ring 111 is jointly arranged in all the ring grooves 110 of each group. Each rubber ring 111 limits each group of slips 105. At the same time, when each group of slips 105 moves away from the sliding tube 104, the rubber ring 111 will be stretched. When the rubber ring 111 breaks, the limit on the slips 105 can be released.

[0043] As Figure 3 and Figure 4 shown, a force-bearing tube 114 and a fixed tube 115 are respectively slidably arranged on the side surfaces of the two sliding tubes 104. The fixed tube 115 is fixedly connected to the outer tube 102. Pressure rings 116 adapted to the inclined surfaces of the slips 105 are installed on the side surfaces of the force-bearing tube 114 and the fixed tube 115. When an external force is applied to the force-bearing tube 114 to move it towards the slips 105, the inclined surface of an adjacent group of slips 105 is squeezed through the pressure ring 116. At the same time, when the other group of slips 105 moves, the inclined surface of it is squeezed by the pressure ring 116 on the fixed tube 115.

[0044] As Figure 3As shown, a fixing ring 117 is installed on the side of the outer tube 102 near the force-bearing tube 114, and a fixing groove 118 is opened on the side of the fixing ring 117. A rubber ring 119 matched with the fixing groove 118 is installed on the other side of the force-bearing tube 114. The moving force-bearing tube 114 will also drive the rubber ring 119 to move until the rubber ring 119 is stuck in the fixing groove 118 matched with it, so that the force-bearing tube 114 can be fixed, thereby enhancing the stability of the device.

[0045] It should be noted that, except for the central tube 101, other structural materials in the main body 1 are laser shock strengthened and have high temperature and high salt resistance.

[0046] In summary, the device is placed into the oil well pipeline with the ball seat 120 as the tail end until it reaches the predetermined blocking position, and then pressure is applied to the force-bearing tube 114. When the force-bearing tube 114 is subjected to external force and moves toward the slip 105, the pressure ring 116 squeezes the inclined surface of an adjacent group of slips 105. At this time, due to the limitation of the rubber ring 111, the slip 105 will not move away from the sliding tube 104. The moving force-bearing tube 114 drives the pressure ring 113 and the soluble rubber ring 112 to move through the slip 105 and the sliding tube 104, and also drives another group of slips 105 to move, until the pressure ring 116 on the fixed tube 115 presses the slip 105 and the pressure ring on the same side. 113 is limited, and the other pressure ring 113 is still moving at this time. The two pressure rings 113 are used to squeeze the soluble rubber ring 112, which will expand under the extrusion state, so as to fit with the inner wall of the sleeve to achieve sealing and blocking. When the soluble rubber ring 112 no longer expands, the two pressure rings 113 stop moving, and then the pressure of the two empty grooves 106 on the inclined surface of the slip 105 becomes larger, forcing the two rubber rings 111 to break, thereby releasing the limit on the slip 105, and each group of slips 105 expands outward until the tooth nail 109 is stuck on the inner wall of the sleeve, thereby fixing the device in the sleeve and blocking it.

[0047] like Figures 5-7 As shown, a sealing mechanism 2 is arranged between the central tube 101 and the outer tube 102, and the sealing mechanism 2 includes a plurality of main baffles 201 uniformly distributed along the axial direction of the central tube 101, and a plurality of sub-baffles 202 uniformly distributed around the circumference of the central tube 101 are arranged between the sealing plate 103 and the adjacent main baffles 201 and between two adjacent main baffles 201. The outer side surface of the main baffle 201 is connected to the inner wall of the outer tube 102, and the other three sides of the sub-baffle 202 between the sealing plate 103 and the adjacent main baffle 201 are respectively connected to the sealing plate 103, the main baffle 201 and the inner wall of the outer tube 102, and the three sides of the sub-baffle 202 between two adjacent main baffles 201 are respectively connected to the corresponding two main baffles 201 and the inner wall of the outer tube 102, and the sealing plate 103 cooperates with the main baffle 201 and the sub-baffle 202 to divide the space between the central tube 101 and the outer tube 102 into a plurality of sub-cavities.

[0048] As shown Figures 6-7 in the figure, a curved plate 203 is arranged in each sub-cavity. The curved plate 203 divides the sub-cavity into two main and auxiliary chambers. Through holes 205 are formed on the side surface of the curved plate 203. A metal seal 204 is arranged in the main chamber to tightly close the through holes 205. The through holes 205 are used to connect the main chamber and the auxiliary chamber. When a gap appears at a certain position of the central tube 101, the metal seal 204 in the corresponding sub-cavity deforms adaptively under a certain pressure to block the gap, preventing liquid from entering between the central tube 101 and the outer tube 102 through the gap.

[0049] As shown Figures 6-7 in the figure, a sealing spring 206 is installed on the side surface of the metal seal 204. The sealing spring 206 passes through the through hole 205 and is connected to the inner wall of the outer tube 102 and is in a compressed state. Injection holes communicating with the main chambers are formed on the inner wall of the central tube on one side of each main chamber. Soluble plugs are arranged in the holes. During the production process, high-pressure gas is injected into the main chambers through the injection holes to make the internal pressure greater than that of the auxiliary chambers. Then, soluble plugs are pressed into the injection holes to block them. When the pressure in the main chambers is greater than that in the auxiliary chambers and a gap appears in the central tube 101, the pressure in the main chambers leaks out through the gap, making the pressures in the main chambers and the auxiliary chambers balanced. The sealing spring 206 rebounds to drive the metal seal 204.

[0050] In summary, during production, high-pressure gas is injected into each main chamber, the pressure in the main chambers increases, pushing the metal seal 204 to tightly adhere to the side surface of the curved plate 203 and simultaneously compressing the sealing spring 206. When a gap appears in the central tube 101, the pressure in the main chambers corresponding to the gap leaks out through the gap, making the pressures in the main chambers and the auxiliary chambers balanced. The sealing spring 206 rebounds to drive the metal seal 204 to deform adaptively under a certain pressure to block the gap, preventing liquid from entering between the central tube 101 and the outer tube 102 through the gap.

[0051] Embodiment 2:

[0052] On the basis of Embodiment 1, as shown Figure 5 , Figure 8 and Figure 9 in the figure, a fixing mechanism 3 is further included. The fixing mechanism 3 includes a plurality of cross plates 301 evenly distributed between the central tube 101 and the outer tube 102 and penetrating through all the main partitions 201. Rectangular grooves 302 are formed on the side surfaces of the cross plates 301 in each sub-cavity. Extension rods 207 passing through the corresponding rectangular grooves 302 in the sub-cavities are installed on the side surfaces of the metal seals 204. Limit blocks 208 adapted to the rectangular grooves 302 are installed at the ends of the extension rods 207. When the limit blocks 208 are aligned with the rectangular grooves 302, the cross plates 301 do not limit the limit blocks 208. When the limit blocks 208 are not aligned with the rectangular grooves 302, they will be limited.

[0053] As Figure 8 and Figure 9 shown, the end of the cross plate 301 extends outside the sealing plate 103 and is installed with a Z-shaped plate 303. The ends of all the Z-shaped plates 303 extend into the ball seat 120 and are jointly installed with a force-bearing ring 304. A return spring 305 is connected between the side surface of the Z-shaped plate 303 and the sealing plate 103. When the plugging ball enters the ball seat 120, it will first squeeze the force-bearing ring 304 to drive it to move. The moving force-bearing ring 304 drives the cross plate 301 to move through the Z-shaped plate 303, compressing the return spring 305, and at the same time, it will also drive the rectangular groove 302 to align with the corresponding limit block 208.

[0054] In summary, when the plugging ball enters the ball seat 120, it will first squeeze the force-bearing ring 304 to drive it to move. The moving force-bearing ring 304 drives the cross plate 301 to move through the Z-shaped plate 303, compressing the return spring 305, and at the same time, it will also drive the rectangular groove 302 to align with the corresponding limit block 208. Furthermore, the cross plate 301 will not limit the limit block 208. When there is a gap, the metal seal 204 adaptively deforms under a certain pressure to block the gap. When the plugging ball melts, the force-bearing ring 304 has no pressure, allowing the return spring 305 to rebound and drive the positions of each cross plate 301 to return to their original positions, so that the rectangular groove 302 is not aligned with the corresponding limit block 208. Furthermore, the cross plate 301 can be used to limit the limit block 208 and the metal seal 204. After a gap appears in the central pipe 101, it will not block the gap, accelerating the dissolution of the device.

[0055] It should be noted that all the structures in this application are made of soluble materials.

[0056] This application also discloses a method for using a detachable soluble bridge plug. The steps of this method are as follows:

[0057] S1. Enter the casing, place the device into the oil well casing, and transport it to the predetermined plugging position. Specifically, take the ball seat 120 as the tail end and place the device into the oil well pipeline. Use an external force to transport the device in the casing until it reaches the predetermined plugging position.

[0058] S2. Sleeve Sealing: Apply pressure to the main body mechanism 1 to block the gap between the device and the sleeve. Specifically, apply pressure to the force-bearing pipe 114. When the force-bearing pipe 114 moves towards the slip joint 105 under an external force, the pressing ring 116 squeezes the inclined surface of an adjacent set of slip joints 105. At this time, due to the limitation of the rubber ring 111, the slip joint 105 will not move away from the sliding pipe 104. The moving force-bearing pipe 114 drives the pressure ring 113 and the soluble glue ring 112 to move through the slip joint 105 and the sliding pipe 104, and at the same time, it will also drive another set of slip joints 105 to move until the pressing ring 116 on the fixed pipe 115 limits the slip joint 105 and the pressure ring 113 on the same side. At this time, the other pressure ring 113 is still moving. Use the two pressure rings 113 to squeeze the soluble glue ring 112. The soluble glue ring 112 will expand in the squeezed state, so as to fit the inner wall of the sleeve.

[0059] S3. Device Fixing: After blocking the sleeve, continue to apply an external force to anchor the stud 109 on the slip joint 105 to the inner wall of the sleeve. Specifically, when the soluble glue ring 112 stops expanding and the two pressure rings 113 stop moving, and at this time, continue to apply pressure to the force-bearing pipe 114. Then, the pressure exerted by the two empty slots 106 on the inclined surface of the slip joint 105 becomes larger, forcing the two rubber rings 111 to break, releasing the limitation on the slip joint 105. Each group of slip joints 105 expands outwards until the stud 109 is anchored to the inner wall of the sleeve, and then the device is fixed in the sleeve.

[0060] S4. Sleeve Blocking: Put a blocking ball into the oil well sleeve to block the port of the ball seat 120, and then block the sleeve. Specifically, when the blocking ball enters the ball seat 120, it will first squeeze the force-bearing ring 304 to drive it to move. The moving force-bearing ring 304 drives the cross plate 301 to move through the Z-shaped plate 303, compressing the return spring 305, and at the same time, it will also drive the rectangular slot 302 to align with the corresponding limit block 208. Then, the blocking ball gets stuck on the inner wall of the ball seat 120 to block it, and thus the entire sleeve blocking is completed.

[0061] S5. Gap Blocking: When there are gaps on the surface of the central pipe 101, use the sealing mechanism 2 to block the gaps. Specifically, add a dissolving liquid into the sleeve to dissolve the device. When the dissolving liquid enters the central pipe 101 from the gap between the blocking ball and the ball seat 120 and generates gaps on its inner wall due to dissolution, the pressure in the main chamber of the corresponding sub-chamber leaks out from the gaps, making the pressures in the main chamber and the sub-chamber balanced. The sealing spring 206 rebounds and drives the metal seal 204 to adaptively deform under a certain pressure to block the gaps, preventing liquid from entering between the central pipe 101 and the outer pipe 102 through the gaps, and avoiding the situation where the dissolving liquid enters between the central pipe 101 and the outer pipe 102 and dissolves both sides of the central pipe 101.

[0062] S5. The structure is fixed. When the predetermined time is reached, the blocking ball shrinks to cooperate with the fixing mechanism 3 to fix the sealing mechanism 2. Specifically, when the predetermined blocking time is reached, the blocking ball gradually shrinks within this time, releases the fixation with the ball seat 120, and the force-receiving ring 304 loses pressure. The return spring 305 rebounds to drive the positions of each cross plate 301 to return to their original positions, so that the rectangular groove 302 is not aligned with the corresponding limit block 208. Furthermore, the cross plate 301 can be used to limit the limit block 208 and the metal seal 204. After a gap appears in the central tube 101, the metal seal 204 cannot move to block the gap. Then, the dissolving liquid can enter the space between the central tube 101 and the outer tube 102 through the gap, accelerating the dissolution of the central tube 101, making the casing conductive, and slowly dissolving the remaining structures in the device in the subsequent time.

[0063] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive.

[0064] In addition, it should be understood that although this specification is described according to the embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A soluble bridge plug that prevents falling off, characterized in that: The main body mechanism includes a central tube, an outer tube with the same center as the central tube is sleeved on the outer side of the central tube, sealing plates are arranged between the head and tail ends of the central tube and the outer tube, and two groups of slips and soluble rubber rings are arranged on the outer side of the outer tube; A sealing mechanism is provided between the central tube and the outer tube, and the sealing mechanism includes a plurality of main baffles evenly distributed along the axial direction of the central tube, and a plurality of sub-baffles evenly distributed around the circumference of the central tube are provided between the sealing plate and the adjacent main baffles and between two adjacent main baffles. The sealing plate cooperates with the main baffles and the sub-baffles to divide the space between the central tube and the outer tube into a plurality of sub-cavities; A curved plate is provided in each sub-chamber, which divides the sub-chamber into two main and sub-chambers. A through hole is provided on the side of the curved plate. The main chamber is provided with a metal seal tightly attached to the curved plate. A sealing spring in a compressed state is installed on the side of the metal seal. The pressure in the main chamber is greater than that in the sub-chamber.

2. The anti-falling soluble bridge plug according to claim 1, characterized in that: A sliding pipe matching with the outer tube is sleeved on the inner side of each group of slips.

3. The anti-falling soluble bridge plug according to claim 2, characterized in that: A hollow groove is provided on the side of the slip, and an arc plate matching with the hollow groove is slidably arranged in the hollow groove. A connecting rod connected with the corresponding sliding pipe is installed at the center of the side of the arc plate.

4. The anti-falling soluble bridge plug according to claim 3, characterized in that: The side surfaces of each group of slips are provided with ring grooves, and rubber rings are arranged in all the ring grooves of each group.

5. The anti-falling soluble bridge plug according to claim 4, characterized in that: A force-bearing pipe and a fixed pipe are slidably arranged on the sides of the two sliding pipes respectively. The fixed pipe is fixedly connected with the outer pipe. The sides of the force-bearing pipe and the fixed pipe are both equipped with pressure rings matched with the inclined surfaces of the slips.

6. The anti-falling soluble bridge plug according to claim 5, characterized in that: A fixing ring is installed on the side of the outer tube near the stress-bearing tube, a fixing groove is opened on the side of the fixing ring, and a rubber ring matched with the fixing groove is installed on the other side of the stress-bearing tube.

7. The anti-dropping soluble bridge plug according to claim 6, characterized in that: It also includes a fixing mechanism, which includes a plurality of transverse plates evenly distributed between the central tube and the outer tube and penetrating all the main partitions, and a rectangular groove is opened on the side of the transverse plate in each sub-cavity.

8. The anti-falling soluble bridge plug according to claim 7, characterized in that: The end of the horizontal plate extends to the outside of the sealing plate and is installed with a Z-shaped plate. The ends of all the Z-shaped plates are commonly installed with a stress ring. A return spring is connected between the side of the Z-shaped plate and the sealing plate.

9. The anti-falling soluble bridge plug according to claim 8, characterized in that: An extension rod passing through a corresponding rectangular groove in the sub-cavity is installed on the side of the metal sealing component, and a limiting block matched with the rectangular groove is installed on the end of the extension rod.

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