Novel high-temperature-resistant split type soluble bridge plug

Abstract

The invention discloses a novel high-temperature-resistant split-type soluble bridge plug. The novel high-temperature-resistant split-type soluble bridge plug is mainly designed in an optimized mode for a sealing assembly and a slip structure. The conical contour sealing ring structure is adopted, the geometrical shape of the conical contour sealing ring structure is matched with the outer contour of a matched cone, the vulcanized rubber sleeve is innovatively covered on the outer surface of the sealing ring base body, the dissolution rate of the sealing ring is effectively delayed through the material synergistic effect, and premature failure of the sealing ring is prevented. Aiming at the sealing requirement of the underground complex working condition, the split slip breaks through the traditional single structure mode, the double-form combined slip of the convex slip and the concave slip with differential functions is innovatively designed, the convex slip achieves the main pressure-bearing anchoring function, the concave slip forms an auxiliary sealing interface, and the main pressure-bearing anchoring function is achieved. The synergistic effect of the two significantly improves the sealing performance of the sealing structure. According to the invention, the dissolution controllability and the sealing reliability are doubly improved.

Description

Technical Field

[0001] The invention relates to the technical field of downhole tools for petroleum, natural gas and shale gas fracturing operations, and in particular to a novel high-temperature resistant petal-type soluble bridge plug. Background Art

[0002] With the continuous development of domestic oil and gas exploration and development, unconventional oil and gas, ultra-deep reservoirs and other areas with high development difficulty have gradually become the focus of research by oil workers. In the 150℃ high temperature formation environment, it has become the core tool for downhole plugging, but the existing soluble bridge plug uses a rubber barrel as a sealing component, which has a poor dissolution effect and may not dissolve. It is even necessary to use drilling and grinding tools to remove the dissolved residues. The use of metal sealing rings alone faces the problem of too fast dissolution under the action of 150℃ formation fluids. Often, the metal sealing ring begins to dissolve before the operation is completed, and the sealing effect of the operation cannot be guaranteed. At the same time, the sealing performance of the metal sealing ring in the split-flap bridge plug is not good. Summary of the invention

[0003] The purpose of the present invention is to propose the use of a metal sealing ring to address the problem that the soluble bridge plug rubber barrel is difficult to dissolve. At the same time, in order to address the problems that the existing metal ring dissolves too quickly and has a poor sealing effect, the metal sealing ring is coated with a circle of vulcanized rubber and the petal-type slip is optimized.

[0004] In order to achieve the above purpose, the technical solution provided by the patent of the present invention is: a new type of high temperature resistant split-petal soluble bridge plug, the device body includes a cone seat, a slip group, a guide shoe, a sealing mechanism, and a slip hoop, wherein:

[0005] The cone seat, slip group and guide shoe are all made of aluminum-based soluble alloy material;

[0006] The slip group is arranged in the middle of the device body, with a cone seat on one side and a guide shoe on the other side. The slip group is composed of three concave slips and three convex slips. Before sealing, the six-petal slips are firmly fixed by the slip ring. When the cone seat descends, the slip ring is squeezed and broken. The slip group then opens under the squeezing action of the cone seat and quickly bites into the casing wall to complete the anchoring. The carrier of the slip group is composed of aluminum-based soluble alloy material, and one end is distributed with inclined slip teeth, so that the slip teeth are evenly stressed when anchoring. The slip teeth are designed as cylindrical structures and are made of ceramic materials, which can improve the reliability of slip anchoring and facilitate backflow;

[0007] The sealing mechanism includes a metal sealing ring and a vulcanized rubber sleeve coated on the outside thereof. The metal sealing ring is made of an aluminum-based soluble alloy material, and the vulcanized rubber sleeve is made of a polymer hydrolyzable material. During operation, the outer vulcanized rubber sleeve dissolves first. When the outer vulcanized rubber sleeve dissolves completely, the inner metal sealing ring begins to dissolve. In this way, the sealing performance of the sealing structure will not fail early. The dissolution rate of a single metal sealing ring is too fast. Coating the outer vulcanized rubber sleeve can significantly reduce the dissolution rate of the sealing mechanism, thereby ensuring the sealing performance of the soluble bridge plug.

[0008] The metal sealing ring and the inner wall of the vulcanized rubber sleeve together form a conical sealing slope, and the sealing structure is arranged outside one end of the device body to form a dynamic seal between the bridge plug and the wellbore casing;

[0009] The first end of the guide shoe is provided with six circular grooves, and the second end is provided with six inclined planes, each of which is provided with a fixing groove;

[0010] The first end of the cone seat is arranged at the conical joint surface, the second end is provided with a ball seat for accommodating a fracturing ball, and the sealing mechanism is fixed to the outer periphery of the cone seat.

[0011] The inner walls of the concave slip and the convex slip are both fixed with a slider, the slider is slidably matched with the fixing groove at the second end of the guide shoe, and the upper and lower ends of the outer walls of the concave slip and the convex slip are both provided with circumferential arc grooves;

[0012] The convex slip is provided with a first protrusion and a second protrusion at the end in contact with the guide shoe, and the two protrusions are symmetrical along the central axis of the slip base and circumferentially distributed on the outside of the slip;

[0013] The concave slip is provided with a first groove portion and a second groove portion at the end in contact with the guide shoe, and the two groove portions are symmetrical along the central axis of the slip base and circumferentially distributed on the outside of the slip;

[0014] The first protrusion of the convex slip forms a complementary fit with the second groove of the adjacent concave slip, and the second protrusion of the convex slip engages with the first groove of another adjacent concave slip, so that a continuous conical joint surface is formed on the inner side of the slip group through the complementary fit;

[0015] The circumferential arc grooves of the concave slips and the convex slips form two circumferential hoop grooves after the adjacent slips are connected. A slip hoop is arranged in the hoop groove to restrict the radial displacement of the slips.

[0016] Beneficial effects of the present invention:

[0017] 1) The sealing structure of the soluble bridge plug of the present invention is a composite metal sealing ring structure. The metal sealing ring and the vulcanized rubber sleeve cooperate with each other. The vulcanized rubber sleeve occupies a small volume, which saves space. While ensuring the sealing performance of the soluble bridge plug to the greatest extent, the problem of too fast dissolution rate caused by the metal sealing ring structure is reduced, thereby avoiding affecting the sealing performance of the overall bridge plug;

[0018] 2) The cava group designed in the present invention is a split-petal type with a differentiated cava group structure, a dual-form combination of convex cava and concave cava with differentiated functions, wherein the convex cava realizes the main pressure-bearing anchoring function, and the concave cava forms an auxiliary sealing interface, and the concave cava will tightly buckle the first protrusion and the second protrusion of the convex cava in its groove portion, thereby improving the sealing performance of the sealing structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be described by way of drawings, in which:

[0020] Figure 1 It is a half-section schematic diagram of the overall structure of the present invention.

[0021] Figure 2 It is an isometric schematic diagram of the overall structure of the present invention.

[0022] Figure 3 It is an isometric schematic diagram of the slip group structure of the present invention.

[0023] Figure 4 It is a schematic diagram of the structure of the sealing ring and the vulcanized rubber of the present invention.

[0024] Figure 5 It is a schematic diagram of the isometric structure of the convex slip of the present invention.

[0025] Figure 6 It is a schematic diagram of the isometric structure of the concave slip of the present invention.

[0026] In the figure, 1- vulcanized rubber sleeve, 2- metal sealing ring, 3- slip ring, 4- guide shoe, 5- cone seat, 6- convex slip, 7- concave slip, 8- slip, 9- device body. DETAILED DESCRIPTION

[0027] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0028] like Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6As shown, a new type of high temperature resistant split-flap soluble bridge plug of the present invention, the device body 9 includes a vulcanized rubber sleeve 1, a metal sealing ring 2, a slip hoop 3, a guide shoe 4, a cone seat 5, a convex slip 6, a concave slip 7 and a slip 8. The vulcanized rubber sleeve 1 and the metal sealing ring 2 are interference fit, and the sealing mechanism composed of the vulcanized rubber sleeve 1 and the metal sealing ring 2 is fixed on the outer periphery of the cone seat 5. A slip group is connected to one side of the cone of the cone seat 5. The slip group is composed of a convex slip 6 and a concave slip 7. A ball seat for accommodating a fracturing ball is provided on the other side of the cone seat 5. A fixed slider is provided on the other side of the slip group to connect the six fixed grooves provided on the guide shoe 4. The slip group is composed of a concave slip 6 and a convex slip 7. The circumferential arc groove formed by the concave slip 6 and the convex slip 7 forms two circumferential hoop grooves after the adjacent slips are connected, and a slip hoop 3 is provided in the hoop groove. During this process, the bridge plug is stuck to the inner wall of the casing under the pumping action of the setting tool; after the fracturing construction is completed, the entire bridge plug is dissolved.

[0029] The working principle of a novel high-temperature resistant petal-type soluble bridge plug of the present invention is: when in use, the bridge plug is connected to the setting tool through the conical seat 5, and the bridge plug is pumped to a predetermined position by a cable. The gunpowder is ignited by the cable to generate high-pressure gas to fill the combustion chamber, and the setting push cylinder pushes the conical seat 5 with the high-pressure gas in the setting tool. Through the extrusion of the conical seat 5, the slip group breaks the slip hoop 3 under the extrusion, and the conical seat 5 and the slip form a self-locking, allowing the petal-type slip to quickly bite into the casing wall. At the same time, the sealing structure is also squeezed and expanded under the push of the conical seat to complete the sealing of the soluble bridge plug.

[0030] The soluble bridge plug optimizes the sealing performance of the metal sealing ring, and the sealing performance of the bridge plug is greatly improved. The soluble metal part of the bridge plug and the vulcanized rubber sleeve 1 will be completely dissolved, and then the wellbore will be fully opened.

[0031] Example:

[0032] like Figure 1 , Figure 2As shown, a new type of high temperature resistant split-flap soluble bridge plug, the device body 9 includes a vulcanized rubber sleeve 1, a metal sealing ring 2, a slip ring 3, a guide shoe 4, a cone seat 5, a convex slip 6, a concave slip 7 and a slip 8. The vulcanized rubber sleeve 1 and the metal sealing ring 2 are interference fit, and the sealing mechanism composed of the vulcanized rubber sleeve 1 and the metal sealing ring 2 is fixed on the outer periphery of the cone seat 5. A slip group is connected to one side of the cone of the cone seat 5. The slip group is composed of a convex slip 6 and a concave slip 7. A ball seat for accommodating a fracturing ball is provided on the other side of the cone seat 5. The inner diameter of the ball seat matches the diameter of the fracturing ball, and the fracturing ball is driven by hydraulic pressure to achieve the sealing action. A fixed slider is provided on the other side of the slip group to connect the six fixed grooves provided on the guide shoe 4. The slip group consists of a concave slip 6 and a convex slip 7. The circumferential arc groove formed by the concave slip 6 and the convex slip 7 forms two circumferential hoop grooves after the adjacent slips are connected. The hoop grooves are provided with slip hoop rings 3. In this process, the bridge plug is stuck to the inner wall of the casing under the pumping action of the setting tool; after the fracturing construction is completed, the bridge plug is completely dissolved as a whole, and the full-bore wellbore is quickly put into production.

[0033] like Figure 3 , Figure 5 , Figure 6 As shown, the slip group is composed of three concave slips 7 and three convex slips 6. The three groups of concave slips 7 and the three groups of convex slips 6 are alternately arranged at the second end of the guide shoe 4, and are slidably connected with the fixed groove on the inclined plane of the guide shoe through the slider on the inner wall of the slip, forming a six-petal split slip structure. The first protrusion 601 of the convex slip 6 is complementary to the second groove part 702 of the adjacent concave slip 7, and at the same time, the second protrusion 602 is engaged with the second groove part (702) of another adjacent concave slip 7, so that a continuous conical joint surface is formed on the inner side of the slip group, realizing the self-locking linkage between the slips. The slip hoop 3 is installed in the circumferential arc groove formed by the concave slip 7 and the convex slip 6, and a double-layer radial constraint is formed by two independent hoops to limit the radial displacement of the slip group during the sealing process.

[0034] like Figure 4 As shown, the sealing mechanism is a metal sealing ring 2 with a vulcanized rubber sleeve 1 wrapped around the outside, and the inner walls of the two together form a conical sealing slope. The metal and rubber composite structure can adapt to the dynamic sealing requirements under high temperature and high pressure environment, and the sealing mechanism is installed on the outer periphery of the cone seat 5.

[0035] In the description of the present invention, it is necessary to understand that if there are terms such as up, down, left, right, inside, outside, radial, etc. indicating orientation or positional relationship, they are based on the orientation or positional relationship shown in the drawings, rather than indicating or implying that the device or element referred to must have a characteristic orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on this patent.

[0036] The above-mentioned embodiments only express the specific implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the protection scope of the present application. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the technical solution concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. A high temperature resistant split-flap soluble bridge plug, the device body (9) comprises a cone seat (5), a slip group, a guide shoe (4), and also includes a sealing mechanism and a slip hoop (3), characterized in that: The cone seat (5), slip group and guide shoe (4) are all made of aluminum-based soluble alloy material; The slip group is arranged in the middle of the device body (9), with a cone seat (5) arranged on one side and a guide shoe (4) arranged on the other side. The slip group is composed of three concave slips (7) and three convex slips (6). Before sealing, the six-petal slips are firmly fixed by the slip ring (3). When the cone seat (5) moves downward, the slip ring is squeezed and broken. The slip group then opens under the squeezing action of the cone seat (5) and quickly bites into the casing wall to complete anchoring. The carrier of the slip group is composed of aluminum-based soluble alloy material, and one end is distributed with inclined slip teeth (8), so that the slip teeth (8) are evenly stressed when anchoring. The slip teeth (8) are designed as a cylindrical structure and are made of ceramic material, which can improve the reliability of slip anchoring and facilitate backflow; The sealing mechanism includes a metal sealing ring (2) and a vulcanized rubber sleeve (1) coated on the outside thereof, wherein the metal sealing ring (2) is made of an aluminum-based soluble alloy material, and the vulcanized rubber sleeve (1) is made of a polymer hydrolyzable material. During operation, the outer vulcanized rubber sleeve (1) dissolves first, and when the outer vulcanized rubber sleeve (1) is completely dissolved, the inner metal sealing ring (2) begins to dissolve, so that the sealing performance of the sealing structure will not fail early. The dissolution rate of a single metal sealing ring is too fast, and coating the outer vulcanized rubber sleeve (1) can significantly reduce the dissolution rate of the sealing mechanism, thereby ensuring the sealing performance of the soluble bridge plug; The metal sealing ring (2) and the inner wall of the vulcanized rubber sleeve (1) together form a conical sealing slope, and the sealing structure is arranged outside one end of the device body (9) to form a dynamic seal between the bridge plug and the wellbore casing; The guide shoe (4) has six circular grooves at the first end and six inclined planes at the second end, each of which has a fixing groove. The first end of the cone seat (5) is arranged at the conical joint surface, and the second end is provided with a ball seat for accommodating a fracturing ball, and the sealing mechanism is fixed to the outer periphery of the cone seat.

2. The high temperature resistant split-petal soluble bridge plug according to claim 1 is characterized in that: The inner walls of the concave slip (7) and the convex slip (6) are both fixed with a slider, the slider is slidably matched with the fixing groove at the second end of the guide shoe, and the upper and lower ends of the outer walls of the concave slip (7) and the convex slip (6) are both provided with circumferential arc grooves; The convex slip (6) is provided with a first protrusion (601) and a second protrusion (602) at the end in contact with the guide shoe (4), and the two protrusions are symmetrical along the central axis of the slip base and circumferentially distributed on the outside of the slip; The concave slip (7) is provided with a first groove portion (701) and a second groove portion (702) at the contact end with the guide shoe (4), and the two groove portions are symmetrical along the central axis of the slip base and circumferentially distributed on the outer side of the slip; The first protruding portion (601) of the convex cava (6) forms a complementary fitting relationship with the second groove portion (702) of the adjacent concave cava (7), and the second protruding portion (602) of the convex cava (6) engages with the first groove portion (701) of another adjacent concave cava (7), thereby forming a continuous conical joint surface on the inner side of the cava group through the complementary fitting relationship.

3. The high temperature resistant split-petal soluble bridge plug according to claim 1 is characterized in that: The circumferential arc grooves of the concave slips (7) and the convex slips (6) form two circumferential hoop grooves after the adjacent slips are connected. A slip hoop (3) is provided in the hoop groove to restrict the radial displacement of the slips.

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