Instant bridge plug

Abstract

The application provides a quick-dissolving bridge plug, which comprises a bridge plug body, a wedge-shaped sealing ring, a locking device, an anchoring body and a lower joint, the bridge plug body comprises a conical section and a cone section connected in sequence, the radial dimension of the connecting position of the conical section and the cone section is larger than the radial dimension of the two ends, and the bridge plug body is provided with a through hole penetrating through the conical section and the cone section; the wedge-shaped sealing ring, the locking device, the anchoring body and the lower joint are arranged on the bridge plug body. The application can improve the pressure-bearing stability and reliability of the bridge plug under high temperature and high pressure conditions in the well, and in addition, the bridge plug can be quickly dissolved in the casing at the well bottom, the dissolution efficiency is high, the residual after dissolution is small, so that the construction period and the economic cost can be reduced.

Description

Technical Field

[0001] This application relates to the field of oil and gas drilling and fracturing technology, and in particular to a fast-dissolving bridge plug. Background Technology

[0002] As major oilfields in my country have successively entered the medium-to-high water-cut stage, the undeveloped formations are gradually developing into thinner and poorer layers. In order to increase oil recovery and improve oilfield production efficiency, stratified injection and production, and multi-stage fracturing are among the effective means of developing special oil layers. Typically, during fracturing, bridge plugs are used to seal the downhole casing and isolate the target formation.

[0003] In related technologies, soluble bridge plugs are commonly used. These are a novel type of shale gas fracturing tool for staged and segmented stimulation. After fracturing, the bridge plug body completely dissolves due to wellbore temperature and a certain level of salinity in the liquid environment, ensuring full-bore production. They offer advantages such as low overall cost, short commissioning time, reduced operational risks, and the ability to perform secondary stimulation. Currently, most common soluble bridge plugs achieve sealing of the downhole casing and interlayer isolation through the elastic deformation of a soluble rubber sleeve under compression.

[0004] However, soluble rubber cylinders have poor tolerance to high-temperature conditions, and the dissolution efficiency is low, the process is long, and there are many residues after dissolution. Summary of the Invention

[0005] In view of the above problems, this application provides a fast-dissolving bridge plug that is applicable to working conditions such as high temperature, high pressure, and high mineralization, and has high dissolution efficiency, short cycle, and little residue after dissolution.

[0006] To achieve the above objectives, the embodiments of this application provide the following technical solutions:

[0007] This application provides a fast-dissolving bridge plug, which is an all-metal soluble bridge plug, comprising:

[0008] A bridge plug body, comprising a conical segment and a tapered segment connected in sequence, wherein the radial dimension at the connection between the conical segment and the tapered segment is greater than the radial dimension at both ends, and the bridge plug body has a through hole penetrating the conical segment and the tapered segment;

[0009] A wedge-shaped sealing ring, the inner surface of which has a tapered surface that matches the outer surface of the conical segment, the wedge-shaped sealing ring being sleeved on the conical segment, the wedge-shaped sealing ring being configured to seal the gap between the bridge plug body and the inner wall of the sleeve;

[0010] A locking device is connected to the end of the wedge-shaped sealing ring away from the conical section and has a wedge-shaped hole penetrating the locking device. The inner surface of the wedge-shaped hole matches the outer surface of the conical section. When the locking device is subjected to an axial force that moves towards the conical section, the inner surface of the wedge-shaped hole moves along the outer surface of the conical section towards the conical section to transmit an axial thrust to the wedge-shaped sealing ring.

[0011] An anchor body has a connecting hole that matches the outer peripheral surface of the conical section. The anchor body is sleeved on the end of the conical section away from the conical section through the connecting hole. When the bridge plug body moves axially from one end of the conical section to one end of the conical section, the surface of the connecting hole moves along the outer surface of the conical section towards the end of the conical section.

[0012] The lower connector is connected to one end of the anchor body away from the conical section, and the lower connector has a threaded hole configured to be threadedly connected to one end of the adapter mandrel.

[0013] In some alternative embodiments, the bridge plug is a magnesium alloy bridge plug; and / or,

[0014] Along the axial direction of the through hole, the radial dimension at both ends of the through hole gradually increases towards the middle.

[0015] In some alternative embodiments, the outer surface of the conical segment near the locking device is provided with anti-slip teeth, and the inner surface of the wedge-shaped hole has limiting teeth that match the anti-slip teeth, the limiting teeth being configured to restrict the anti-slip teeth from moving away from the end of the conical segment.

[0016] In some alternative embodiments, the locking device includes a hoop and a plurality of locking push blocks, the plurality of locking push blocks being distributed circumferentially along the conical segment to collectively enclose a wedge-shaped hole; the hoop is configured to clamp the plurality of locking push blocks circumferentially.

[0017] In some alternative embodiments, mounting grooves are provided on the outer surfaces of the plurality of locking push blocks, and the hoop is located within the mounting grooves.

[0018] In some alternative embodiments, the outer surface of the wedge-shaped sealing ring is provided with a plurality of extension grooves, which are spaced apart along the axial direction of the bridge plug body.

[0019] In some alternative embodiments, a push ring is further included, which abuts against the end of the locking device away from the conical section; and / or a retaining ring is further included, which is sleeved on the conical section and connected to the end of the wedge seal near the conical section, and the inner hole of the retaining ring is a conical surface that matches the outer surface of the cone.

[0020] In some alternative embodiments, the anchor body includes a plurality of anchor blocks arranged circumferentially along the bridge plug body, with gaps between adjacent anchor blocks and connecting ribs disposed in the gaps, the connecting ribs being configured to connect two adjacent anchor blocks, and the connecting ribs being configured to disconnect when the anchor body is subjected to an axial external force.

[0021] Anchoring teeth are embedded on the outer surface of the anchoring block. Part of the anchoring teeth protrudes from the outer surface of the anchoring block, and the anchoring teeth have an inclined angle relative to the outer surface of the anchoring block.

[0022] In some alternative embodiments, the lower connector has a tapered stepped surface at one end near the anchor body, the stepped surface being configured to support the anchor body;

[0023] The lower connector is provided with a guide cone surface at the end opposite to the anchor body, the guide cone surface being configured to guide the bridge plug; and / or, it also includes a soluble ball, the soluble ball being configured to block the end of the through hole opposite to the lower connector.

[0024] In some alternative embodiments, a release mandrel and a pusher cylinder are also included. The release mandrel is a hollow structure with an external thread on the outer surface of one end. The release mandrel is configured to pass through the through hole and the external thread is threadedly connected to the threaded hole of the lower connector. The pusher cylinder is a cylindrical structure and is disposed on the side of the push ring away from the locking device, and abuts against the push ring. The release mandrel and the pusher cylinder form the adapter mandrel.

[0025] Compared with related technologies, the bridge plug provided in this application has at least the following advantages:

[0026] The fast-dissolving bridge plug provided in this application embodiment is an all-metal soluble bridge plug. The fast-dissolving bridge plug includes: a bridge plug body comprising a conical segment and a tapered segment connected in sequence, the radial dimension at the connection point of the conical segment and the tapered segment being larger than the radial dimensions at both ends; the bridge plug body having a through hole penetrating the conical segment and the tapered segment; a wedge-shaped sealing ring, the inner surface of which has a tapered surface matching the outer surface of the conical segment; the wedge-shaped sealing ring being sleeved on the conical segment and configured to seal the gap between the bridge plug body and the inner wall of the sleeve; and a locking device connected to the end of the wedge-shaped sealing ring away from the tapered segment, having a wedge-shaped hole penetrating the locking device, the inner surface of which is flush with the conical segment. The outer surface of the segment matches the locking device. When the locking device is subjected to an axial force moving towards the conical segment, the inner surface of the wedge-shaped hole moves along the outer surface of the conical segment towards the conical segment to transmit axial thrust to the wedge-shaped sealing ring. The anchor body has a connecting hole that matches the outer circumferential surface of the conical segment. The anchor body is sleeved on the end of the conical segment away from the conical segment through the connecting hole. When the bridge plug body moves axially from one end of the conical segment to the other end of the conical segment, the surface of the connecting hole moves along the outer surface of the conical segment towards the end of the conical segment. The lower connector is connected to the end of the anchor body away from the conical segment and has a threaded hole configured to connect with the external thread of one end of the adapter mandrel. In the above scheme, the pressure-bearing stability and reliability of the bridge plug under high temperature and high pressure conditions downhole can be improved. In addition, the bridge plug can be quickly dissolved in the bottom casing, with high dissolution efficiency and less residue after dissolution, thereby reducing the construction cycle and economic cost.

[0027] In addition to the technical problems solved by the embodiments of this application, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that can be solved by the fast-dissolving bridge plugs provided by the embodiments of this application, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in the specific implementation. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of the fast-dissolving bridge plug provided in the embodiments of this application;

[0030] Figure 2 This is a schematic diagram of the setting and anchoring working state of the fast-dissolving bridge plug provided in the embodiments of this application;

[0031] Figure 3 This is a schematic diagram of the locking push block in the fast-dissolving bridge plug provided in an embodiment of this application;

[0032] Figure 4 A partial structural schematic diagram of the bridge plug body provided in an embodiment of this application;

[0033] Figure 5 This is a schematic diagram of the overall structure of the anchor body in the quick-dissolving bridge plug provided in an embodiment of this application.

[0034] Explanation of reference numerals in the attached figures:

[0035] 100 - Instant-dissolving bridge plug; 110 - Bridge plug body; 111 - Conical section;

[0036] 1111 - Anti-slip teeth; 112 - Conical section; 113 - Through hole;

[0037] 120 - Anchor body; 121 - Anchor block; 122 - Anchor tooth;

[0038] 130 - Lower connector; 131 - Threaded hole; 132 - Stepped surface;

[0039] 133 - Guide cone surface; 140 - Locking device; 141 - Locking push block;

[0040] 1411 - Limiting tooth; 142 - Hoop ring; 1421 - Mounting groove;

[0041] 150 - Wedge-shaped sealing ring; 151 - Extension groove; 160 - Push ring;

[0042] 170 - Retaining ring; 180 - Soluble ball; 190 - Release spindle; 210 - Push tube;

[0043] 300-sleeve. Detailed Implementation

[0044] To make the above-mentioned objectives, features, and advantages of the embodiments of this application more apparent and understandable, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0045] Figure 1 This is a schematic diagram of the structure of the fast-dissolving bridge plug provided in the embodiments of this application; Figure 2 This is a schematic diagram of the setting and anchoring working state of the fast-dissolving bridge plug provided in the embodiments of this application; Figure 3This is a schematic diagram of the locking push block in the fast-dissolving bridge plug provided in an embodiment of this application; Figure 4 A partial structural schematic diagram of the bridge plug body provided in an embodiment of this application; Figure 5 This is a schematic diagram of the overall structure of the anchor body in the quick-dissolving bridge plug provided in an embodiment of this application.

[0046] This application provides a fast-dissolving bridge plug 100, which is an all-metal soluble bridge plug. For example, the fast-dissolving bridge plug 100 can be a fast-dissolving magnesium alloy bridge plug. In this way, the fast-dissolving bridge plug 100 can be quickly dissolved under specific conditions after the work is completed. Moreover, the magnesium alloy fast-dissolving bridge plug 100 has high dissolution efficiency, short dissolution cycle, and less residue after dissolution. This can effectively ensure that unconventional oil and gas wells can be quickly put into production after staged fracturing operations, reducing construction cycle and economic costs.

[0047] The structure of the quick-dissolving bridge plug 100 will be described in detail below with reference to the accompanying drawings.

[0048] Please refer to Figure 1 and Figure 2 The instant bridge plug 100 includes a bridge plug body 110, which includes a conical segment 111 and a cone segment 112 connected in sequence. The radial dimension at the connection between the conical segment 111 and the cone segment 112 is greater than the radial dimension at both ends. The bridge plug body 110 has a through hole 113 that passes through the conical segment 111 and the cone segment 112.

[0049] The cross-sectional shape of the conical segment 112 can be circular or polygonal. For example, the cross-sectional shape of the conical segment 112 can be pentagonal or hexagonal. When the cross-sectional shape of the conical segment 112 is circular, that is, the conical segment 112 is also a conical structure, the bridge plug body 110 is formed as a double-sided conical structure, and the radial dimensions at both ends of the bridge plug body 110 are smaller than the radial dimensions at the middle position of the bridge plug body 110.

[0050] In addition, the axis of the through hole 113 penetrating the bridge plug body 110 can coincide with the axis of the bridge plug body 110. The radial dimension of the through hole 113 can also be larger in the middle than at both ends to expand the size of the through hole 113 and increase its surface area. On the one hand, this can reduce the material of the bridge plug body 110 and save material costs; on the other hand, increasing the surface area of ​​the through hole 113 can increase the dissolution area of ​​the subsequent bridge plug body 110, thereby improving dissolution efficiency, shortening the dissolution cycle, and thus shortening the overall project schedule and reducing costs.

[0051] In some embodiments, the opening of the through hole 113 near one end of the conical section 111 can be configured as an inner conical surface to facilitate guidance and restraint when the adapter mandrel passes through.

[0052] The wedge-shaped sealing ring 150 has an inner surface that matches the outer surface of the conical segment 111, and the wedge-shaped sealing ring 150 is fitted onto the conical segment 111.

[0053] It is understood that the wedge-shaped sealing ring 150 has an annular structure and the inner hole of the wedge-shaped sealing ring 150 is a conical surface. This conical surface fits with the outer surface of the conical section 111 of the bridge plug body 110. Under the action of axial thrust, the wedge-shaped sealing ring 150 can expand and deform radially along the conical surface of the conical section 111, so that at least a portion of the wedge-shaped sealing ring 150 is wedged into the annular gap between the bridge plug body 110 and the inner wall of the sleeve 300, thereby sealing the gap between the bridge plug body 110 and the inner wall of the sleeve 300.

[0054] In some embodiments, a plurality of spaced-apart extension grooves 151 are provided on the outer surface of the wedge-shaped sealing ring 150. The plurality of extension grooves 151 are spaced-apart along the axial direction of the bridge plug body 110. By providing extension grooves 151, the radial extension and deformation capability of the wedge-shaped sealing ring 150 can be improved, thereby improving the sealing performance.

[0055] In some embodiments, the wedge-shaped sealing ring 150 may be made of a highly ductile and quick-dissolving material and coated with a high-temperature resistant and corrosion-resistant coating to improve the working reliability of the wedge-shaped sealing ring 150 under high temperature, high pressure and other working conditions.

[0056] The quick-dissolving bridge plug 100 also includes a locking device 140 connected to the end of the conical section 111 opposite to the conical section 112, and has a wedge-shaped hole penetrating the locking device 140. The inner surface of the wedge-shaped hole matches the outer surface of the conical section 111. When the locking device 140 is subjected to an axial force moving towards the conical section 112, the inner surface of the wedge-shaped hole moves along the outer surface of the conical section 111 towards the conical section 112. The locking device 140 mainly transmits the axial thrust to the wedge-shaped sealing ring 150 to push the wedge-shaped sealing ring 150 to expand along the conical surface of the conical section 111, so that the wedge-shaped sealing ring 150 is finally wedged into the annular gap between the bridge plug body 110 and the inner wall of the sleeve 300, thereby locking the bridge plug body 110.

[0057] It is understood that the inner surface of the wedge-shaped hole is a conical surface, and the inclination direction and inclination angle of the conical surface are the same as the inclination direction and angle of the conical segment 111. The locking device 140 is mainly used to move axially on the outer surface of the conical segment 111 while the quick-dissolving bridge plug 100 is subjected to axial thrust, so as to provide axial thrust to the wedge-shaped sealing ring 150.

[0058] In some embodiments, the locking device 140 includes a plurality of locking push blocks 141 and a hoop 142. The plurality of locking push blocks 141 are distributed circumferentially along the conical segment 111 to jointly enclose a wedge-shaped hole. The hoop 142 is configured to clamp at least two locking push blocks 141 circumferentially to radially limit each locking push block 141.

[0059] Understandably, please refer to Figure 3 The locking push block 141 is wedge-shaped, and multiple locking push blocks 141 are arranged circumferentially along the bridge plug body 110. They are clamped and initially positioned by the clamping ring 142. Multiple locking push blocks 141 are arranged together to form a wedge-shaped hole, and the inner surface of the wedge-shaped hole is a conical surface that matches the conical surface of the outer surface of the conical section 111. This allows at least two locking push blocks 141 to move along the surface of the conical section 111 when the locking device 140 is subjected to axial thrust, so that the inner surface of the wedge-shaped hole fits against the outer surface of the conical section 111.

[0060] The number of locking push blocks 141 varies depending on the overall size of the quick-dissolving bridge plug 100. For example, the number of locking push blocks 141 can be 6 to 16, and the specific design can be adapted according to actual needs. No specific limitation is made here.

[0061] The main function of the locking push block 141 is that, under the action of axial force, each locking push block 141 expands radially along the upper conical surface of the conical body, while transmitting axial thrust to the wedge-shaped sealing ring 150, and pushing it to expand along the conical surface, and finally wedging between the conical body and the sleeve 300, locking the position of the wedge-shaped sealing ring 150.

[0062] In addition, a mounting groove 1421 is provided at the corresponding position on the outer surface of each locking push block 141. When the clamping ring 142 clamps each locking push block 141, the clamping ring 142 is located in the mounting groove 1421 to prevent the clamping ring 142 from moving axially relative to the locking push block 141.

[0063] In some embodiments, a retaining ring 170 is provided on the side of the wedge-shaped sealing ring 150 away from the locking device 140. The retaining ring 170 is sleeved on the outer surface of the conical section 111. The retaining ring 170 has a wedge-shaped ring structure, that is, the inner hole of the retaining ring 170 is a conical surface that matches the outer surface of the conical section 111. One end of the retaining ring 170 is in contact with the wedge-shaped sealing ring 150, which plays a supporting and protective role for the wedge-shaped sealing ring 150 and can reduce the deformation of the wedge-shaped sealing ring 150 under pressure.

[0064] In some embodiments, please refer to Figure 4The outer surface of the conical segment 111 near the locking device 140 is provided with anti-slip teeth 1111, and the inner surface of the wedge-shaped hole has a limiting tooth 1411 that matches the anti-slip teeth 1111. The limiting tooth 1411 is configured to restrict the anti-slip teeth 1111 from moving away from the end of the conical segment 112.

[0065] For example, the outer surface of the end of the conical segment 111 facing away from the conical segment 112 is provided with multiple, for example, serrated steps to form anti-slip teeth 1111. Correspondingly, multiple, for example, serrated steps are also provided on the inner and outer surfaces of the wedge-shaped hole of the locking device 140. In this way, when the locking push block 141 is pressed against the outer surface of the conical segment 111, it can lock and prevent slippage on the bridge plug body 110, thereby improving its locking reliability.

[0066] Please refer to Figure 1 , Figure 2 and Figure 5 The quick-dissolving bridge plug 100 also includes an anchoring body 120, which has a connecting hole that matches the outer peripheral surface of the conical section 112. The anchoring body 120 is sleeved on the end of the conical section 112 away from the conical section 111 through the connecting hole. When the bridge plug body 110 moves axially from one end of the conical section 111 to one end of the conical section 112, the surface of the connecting hole moves axially along the outer surface of the conical section 112 towards the end of the conical section 111, and at the same time moves radially relative to the conical section 112 along the through hole 113, so that the anchoring body 120 is anchored to the inner wall of the casing 300 in the well, thereby achieving the purpose of anchoring the bridge plug body 110 to the casing 300 through the anchoring body 120.

[0067] In some embodiments, the anchor body 120 includes a plurality of anchor blocks 121, that is, the anchor body 120 has a multi-lobed structure, and at least two anchor blocks 121 are arranged circumferentially along the bridge plug body 110 and connected to form an annular structure with a connecting hole, wherein the formed connecting hole is a conical structure, that is, the inner surface of the connecting hole is a conical surface, and the inclination angle of the connecting hole is the same as the inclination direction and inclination angle of the conical segment 112 in the bridge plug body 110.

[0068] In some embodiments, adjacent anchor blocks 121 have gaps and connecting ribs disposed within the gaps, the connecting ribs being configured to connect two adjacent anchor blocks 121. Optionally, the anchor body 120 can be formed by an integral molding process, and then, by forming a plurality of narrow grooves spaced circumferentially along the outer peripheral surface of the anchor body 120, the anchor body 120 is initially divided into multiple segments, and the portion connecting adjacent anchor blocks 121 serves as the connecting rib, connecting the multiple segments of the anchor blocks 121 into a whole. Since the strength of the connecting rib portion between adjacent anchor blocks 121 is relatively weak, when the anchor body 120 is subjected to an axial force extending from the conical segment 111 to the conical segment 112, the anchor... As the anchor 120 moves along the conical surface of the conical section 112 toward the conical section 111, it also moves radially relative to the conical section 112 along the connecting hole. As a result, the anchor 120 expands outward in the radial direction, causing the connecting rib to break. At this time, each anchor block 121 separates from each other, and the anchor 120 disintegrates into multiple separate anchor blocks 121. Driven by the axial force, it further moves axially along the conical section 112 while expanding radially until each anchor block 121 is close to the inner wall of the sleeve 300.

[0069] In other embodiments, one end of the anchor body 120 has a plurality of circumferentially spaced and evenly distributed slits. The slits extend from one end of the anchor body 120 to the other end, and the length of the slits is less than the overall length of the anchor body 120. The slits can divide the anchor body 120 into a multi-segment structure. In addition, a U-shaped groove is provided at the other end of the anchor body 120 at the position corresponding to each slit. The connection between each slit and its corresponding U-shaped groove forms a connecting rib of adjacent anchor blocks 121. Since the strength of the connecting rib is relatively weak, when the anchor body 120 is subjected to axial thrust, each anchor block 121 moves axially and expands radially at the same time. The connecting rib breaks, and adjacent anchor blocks 121 separate from each other, so that the anchor blocks 121 can continue to expand radially under the action of axial thrust to get close to the inner wall of the sleeve 300.

[0070] In some embodiments, the initial number of segments of the anchor body 120 can typically be 6 to 12, that is, the number of anchor blocks 121 can be 6 to 12. For example, the number of anchor blocks 121 can be 6, 7, 8, 9, 10, 11 or 12, etc. For example, in this application, the number of anchor blocks 121 can be 7. The specific number can be adapted to actual needs and is not specifically limited here.

[0071] In some embodiments, anchoring teeth 122 are embedded on the outer surface of each anchoring block 121. Part of the anchoring teeth 122 protrudes from the outer surface of the anchoring block 121. The anchoring teeth 122 mainly help the anchoring body 120 to gradually bite into the inner wall of the sleeve 300 under the action of axial force, thereby achieving a firm anchoring of the anchoring body 120 and the sleeve 300, thereby improving the stability and reliability of the quick-dissolving bridge plug 100 in the sleeve 300.

[0072] In some embodiments, there can be multiple anchoring teeth 122. For example, the number of anchoring teeth 122 can be 3 to 6, such as 3, 4, 5 or 6. The multiple anchoring teeth 122 are arranged at intervals on the outer surface of the anchoring body 120. For example, when there are 4 anchoring teeth 122, the 4 anchoring teeth 122 can be arranged in a trapezoidal, rectangular or rhomboid distribution on the outer peripheral surface of the anchoring body 120. Alternatively, when there are 3 anchoring teeth 122, the 3 anchoring teeth 122 are arranged in a triangular distribution. The specific distribution can be determined according to the actual needs based on the number of anchoring teeth 122.

[0073] In some embodiments, the outer surface of the anchor body 120 is provided with an embedding hole having a certain angle of inclination with the axis of the connecting hole, for embedding the anchor block 121. That is, the anchor block 121 is embedded in the embedding hole. Since the bottom wall of the embedding hole is an inclined surface with a certain angle of inclination, when the anchor block 121 is embedded in the embedding hole, the surface of the anchor block 121 is also in an inclined state, so that when the anchor body 120 is anchored to the sleeve 300 under the action of axial force, it gradually bites into the inner wall of the sleeve 300 by point anchoring, so as to facilitate the engagement between the anchor teeth 122 and the inner wall of the sleeve 300, thereby improving the anchoring reliability.

[0074] In some embodiments, the lower connector 130 is connected to one end of the anchor body 120 away from the conical section 112, and the lower connector 130 has a threaded hole 131 configured to be threadedly connected to an external thread at one end of the adapter mandrel.

[0075] Understandably, when the quick-dissolving bridge plug 100 moves to the designated position under the action of axial force, after the quick-dissolving bridge plug 100 is no longer subjected to axial thrust and moves axially, the adapter mandrel transmits a certain axial tensile force to the quick-dissolving bridge plug 100. At this time, the internal thread of the lower connector 130 can be sheared and broken under the action of the axial tensile force of the adapter mandrel, thereby realizing the release and setting of the quick-dissolving bridge plug 100.

[0076] The lower connector 130 is provided with a stepped surface 132 at one end near the anchor body 120. The stepped surface 132 is used to support the anchor body 120. Optionally, the stepped surface 132 can be a conical stepped surface 132.

[0077] In some embodiments, the end of the lower connector 130 facing away from the anchor body 120 may also be provided with a guide cone surface 133, so as to guide the axial movement of the quick-dissolving bridge plug 100 through the guide cone surface 133.

[0078] It is understandable that the adapter mandrel is an auxiliary tool for lowering the quick-dissolving bridge plug 100 into the well, and its axial direction is used to fix the bridge plug body 110 and transmit axial load to the bridge plug body 110.

[0079] In some embodiments, the adapter mandrel includes a release mandrel 190 and a pusher 210. The release mandrel 190 is a hollow structure, and the outer surface of one end of the release mandrel 190 has an external thread. The release mandrel 190 is configured to pass through the through hole 113 of the bridge plug body 110 and is connected to the internal thread of the lower connector 130 through the external thread. This allows the release mandrel 190 to drive the quick-dissolving bridge plug 100 to move within the sleeve 300. When the quick-dissolving bridge plug 100 moves to, for example, the setting position, the release mandrel 190 transmits a certain axial tension to the quick-dissolving bridge plug 100. At this time, the internal thread of the lower connector 130 can be sheared and broken under the action of the axial tension of the release mandrel 190, thereby realizing the release and setting of the quick-dissolving bridge plug 100.

[0080] In some embodiments, the end of the release mandrel 190 facing the anchor body 120 is provided with a conical step, which can engage with the inner conical surface of the through hole 113 of the conical section 111 of the bridge plug body 110. The end of the release mandrel 190 away from the lower connector 130 can be connected to the standard setting tool when the quick-dissolving bridge plug 100 is lowered into the well, so as to axially fix the bridge plug body 110 and transmit axial thrust to the bridge plug body 110.

[0081] In some embodiments, a push ring 160 is also included. The push ring 160 may be annular. The inner hole of the push ring 160 may cooperate with the release spindle 190, that is, the push ring 160 is sleeved on the release spindle 190, and the push ring 160 is located on the side of the locking device 140 away from the wedge-shaped sealing ring 150. Optionally, the side of the push ring 160 near the locking device 140 may be provided with a plurality of guide ribs evenly distributed in the circumferential direction, and the end of the locking push block 141 may be provided with a guide groove that matches the guide ribs. The number of guide ribs is the same as the number of guide grooves. In this way, when the locking device 140 expands radially, the guide ribs can guide it, thereby improving the accuracy of its movement during expansion.

[0082] In some embodiments, a pusher cylinder 210 is also included. The pusher cylinder 210 may be in the shape of a thin-walled cylinder. The pusher cylinder 210 is disposed on the side of the pusher ring 160 away from the locking device 140 and abuts against the end face of the pusher ring 160. The other side of the pusher cylinder 210 is connected to the standard setting tool when the quick-dissolving bridge plug 100 is lowered into the well, so as to transmit axial thrust to the pusher ring 160, so as to transmit the axial thrust to the locking device 140 through the pusher ring 160, so that the locking device 140 moves axially under the action of the axial thrust and expands radially at the same time.

[0083] In some embodiments, a soluble ball 180 is also included. The soluble ball 180 is spherical and can be made of a fast-dissolving metal material. The diameter of the soluble ball 180 can be determined by the aperture of the through hole 113 of the bridge plug body 110. After the fast-dissolving bridge plug 100 is set downhole, the soluble ball 180 is attached to the end face of the through hole 113 of the bridge plug body 110 away from the lower connector 130, thereby sealing the through hole 113.

[0084] The above-mentioned solution can improve the pressure-bearing stability, sealing performance and reliability of the quick-dissolving bridge plug 100 under high temperature and high pressure conditions downhole. In addition, the quick-dissolving bridge plug 100 can dissolve rapidly inside the bottom casing 300, with high dissolution efficiency and less residue after dissolution, thereby reducing the construction cycle and economic cost.

[0085] The specific implementation method of the above scheme is described below.

[0086] The process of setting, anchoring, and bearing pressure of the quick-dissolving bridge plug 100 downhole involves first using a standard setting tool on the tool string to provide a certain setting force to release the quick-dissolving bridge plug 100 and set it in a designated position within the casing 300. The anchoring body 120 expands radially and adheres tightly to the inner wall of the casing 300, while the anchoring teeth 122 bite into the inner wall of the casing 300 to form initial anchoring. Then, during the fracturing operation, as the pressure inside the wellbore continues to rise, the anchoring teeth 122 further bite into the inner wall of the casing 300, maintaining the anchoring state of the quick-dissolving bridge plug 100 tends to be stable. Therefore, when the quick-dissolving bridge plug 100 is used downhole, several key elements are: firstly, the quick-dissolving bridge plug 100 can be smoothly released, detached from the setting tool, and form initial anchoring and setting at the designated position on the bottom casing 300; secondly, and more importantly, the quick-dissolving bridge plug 100 has a certain sealing pressure bearing capacity and effective pressure bearing time under certain temperature and salinity conditions at the bottom of the well; that is, during the fracturing operation, under certain temperature and pressure conditions, the sealing pressure bearing stability and anchoring reliability of the quick-dissolving bridge plug 100 can meet the actual process requirements.

[0087] Please return to the reference. Figure 1The components of the instant bridge plug 100 are assembled and fixed onto the release mandrel 190 in sequence. The ends of the release mandrel 190 and the push cylinder 210 that are away from the lower connector 130 are respectively connected to the standard setting tool by threads. By adjusting the distance of the thread engagement, the push cylinder 210 is axially pressed against the left end face of the push ring 160, ensuring that the components of the instant bridge plug 100 push ring 160 and the lower connector 130 are tightly fitted.

[0088] When the setting tool is working, it can provide axial thrust to the push cylinder 210. While the push cylinder 210 moves axially, under the action of the push ring 160 and the lower connector 130, the locking push block 141, wedge sealing ring 150, retaining ring 170 and anchor body 120 at both ends of the bridge plug body 110 all tend to expand along their corresponding conical surfaces. Under the action of the conical surfaces, part of the axial force is converted into radial force. When the axial thrust reaches a certain value, the hoop ring 142 of the locking push block 141 and the connecting ribs between the segments of the anchor body 120 break one after another. Then, each component expands rapidly until it is completely pressed against the inner wall of the sleeve 300, locking the setting position of the quick-dissolving bridge plug 100.

[0089] After the quick-dissolving bridge plug 100 is locked, under the axial force provided by the setting tool, the axial pressure on the release mandrel 190 instantly shears and breaks the internal thread of the lower connector 130, completing the release setting of the quick-dissolving bridge plug 100. At this time, the anchoring teeth 122 bite into the inner wall of the sleeve 300 in a small amount, establishing the initial anchoring of the quick-dissolving bridge plug 100; the wedge-shaped sealing ring 150 and the retaining ring 170 expand along the conical surface into the annular space gap between the bridge plug body 110 and the sleeve 300 under the action of the locking push ring 160, forming an initial seal; and after the locking push block 141 wedges into the annular space between the bridge plug body 110 and the inner wall of the sleeve 300, its position is locked by the interlocking of the sawtooth steps on the inner conical surface of the locking push block 141 with the sawtooth steps on the conical section 111 and the interlocking of the sawtooth steps on the outer surface of the locking push block 141 with the inner wall of the sleeve 300.

[0090] Please return to the reference. Figure 2The quick-dissolving bridge plug 100 completes initial anchoring and setting at a designated location downhole. After all components are locked, according to the fracturing operation requirements, a soluble ball 180 is deployed from the wellhead and continuously pumped to the end face of the through hole 113 of the bridge plug body 110 of the quick-dissolving bridge plug 100 at the bottom of the well, completing the ball setting and sealing the through hole 113 of the bridge plug body 110; thus achieving overall sealing of the wellbore within the casing 300. Furthermore, during the fracturing operation, as the pressure inside the wellbore continues to rise, the anchoring teeth 122 further bite into the inner wall of the casing 300, achieving stable anchoring of the quick-dissolving bridge plug 100; and further compacting the wedge-shaped sealing ring 150. Under the support and protection of the retaining ring 170 and the left end face of the anchoring body 120, the wedge-shaped sealing ring 150 is in a state of increasing tightness, thereby establishing an effective seal inside the wellbore and completing the pressure-bearing and fracturing operation for a certain period of time.

[0091] After fracturing operations are completed, the quick-dissolving bridge plug 100 can rapidly dissolve on its own under certain temperature and salinity conditions at the bottom of the well. As the dissolution process continues, the components of the quick-dissolving bridge plug 100 will detach from the inner wall of the casing 300, eventually dissolving completely into fine powdery residue. Furthermore, the higher the bottom-hole temperature and salinity, the faster the dissolution rate and the shorter the time required for complete dissolution.

[0092] The bridge plug provided in this application embodiment is a soluble metal bridge plug, comprising: a bridge plug body, the bridge plug body including a conical segment and a tapered segment connected in sequence, the radial dimension at the connection of the conical segment and the tapered segment being greater than the radial dimensions at both ends, and the bridge plug body having a through hole penetrating the conical segment and the tapered segment; a wedge-shaped sealing ring, the inner surface of the wedge-shaped sealing ring having a tapered surface matching the outer surface of the conical segment, the wedge-shaped sealing ring being sleeved on the conical segment, and the wedge-shaped sealing ring being configured to seal the gap between the bridge plug body and the inner wall of the sleeve; and a locking device connected to the end of the wedge-shaped sealing ring away from the tapered segment, and having a wedge-shaped hole penetrating the locking device, the inner surface of the wedge-shaped hole being flush with the outer surface of the conical segment. The surface of the locking device matches the outer surface of the conical section. When the locking device is subjected to an axial force moving towards the conical section, the inner surface of the wedge-shaped hole moves along the outer surface of the conical section towards the conical section to transmit axial thrust to the wedge-shaped sealing ring. The anchor body has a connecting hole that matches the outer circumferential surface of the conical section. The anchor body is fitted onto the end of the conical section away from the conical section through the connecting hole. When the bridge plug body moves axially from one end of the conical section to the other, the surface of the connecting hole moves along the outer surface of the conical section towards the end of the conical section. The lower connector is connected to the end of the anchor body away from the conical section and has a threaded hole configured to connect with the external thread of one end of the adapter mandrel. This design improves the pressure-bearing stability and reliability of the bridge plug under high temperature and high pressure conditions downhole. Furthermore, the bridge plug can dissolve rapidly inside the well casing with high dissolution efficiency and minimal residue, thereby reducing construction time and economic costs.

[0093] The various embodiments or implementation methods described in this specification are presented in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other.

[0094] In the description of this application, "multiple" means two or more, unless otherwise specified precisely.

[0095] In the description of this specification, references to "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. 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.

[0096] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A fast-dissolving bridge plug, characterized in that, The fast-dissolving bridge plug is an all-metal soluble bridge plug, the bridge plug is a magnesium alloy bridge plug, and the bridge plug comprises: A bridge plug body, comprising a conical segment and a tapered segment connected in sequence, wherein the radial dimension at the connection between the conical segment and the tapered segment is greater than the radial dimension at both ends, and the bridge plug body has a through hole penetrating the conical segment and the tapered segment, wherein the radial dimension at both ends of the through hole gradually increases towards the middle along the axial direction of the through hole; A wedge-shaped sealing ring has an inner surface that matches the outer surface of the conical segment. The wedge-shaped sealing ring is sleeved on the conical segment and is configured to seal the gap between the bridge plug body and the inner wall of the sleeve. The outer surface of the wedge-shaped sealing ring is provided with a plurality of extension grooves, which are spaced apart along the axial direction of the bridge plug body. A locking device is connected to the end of the wedge-shaped sealing ring opposite to the conical section and has a wedge-shaped hole penetrating the locking device. The inner surface of the wedge-shaped hole matches the outer surface of the conical section. When the locking device is subjected to an axial force moving towards the conical section, the inner surface of the wedge-shaped hole moves along the outer surface of the conical section towards the conical section to transmit an axial thrust to the wedge-shaped sealing ring. The locking device includes a plurality of locking push blocks. An anchor body has a connecting hole that matches the outer peripheral surface of the conical section. The anchor body is sleeved on the end of the conical section away from the conical section through the connecting hole. When the bridge plug body moves axially from one end of the conical section to one end of the conical section, the surface of the connecting hole moves along the outer surface of the conical section towards the end of the conical section. The lower connector is connected to one end of the anchor body away from the conical section, and the lower connector has a threaded hole configured to be threadedly connected to an external thread at one end of the adapter mandrel. A push ring abuts against the end of the locking device away from the conical section. The push ring has multiple guide ribs evenly distributed circumferentially on the side near the locking device. The end of the locking push block is provided with a guide groove that matches the guide ribs. The locking device is configured such that the guide ribs can slide along the guide groove when expanding radially. A retaining ring is sleeved on the conical section and connected to one end of the wedge-shaped sealing ring near the conical section, and the inner hole of the retaining ring is a conical surface that matches the outer surface of the conical section.

2. The fast-dissolving bridge plug according to claim 1, characterized in that, The outer surface of the conical segment near the locking device is provided with anti-slip teeth, and the inner surface of the wedge-shaped hole has limiting teeth that match the anti-slip teeth. The limiting teeth are configured to restrict the anti-slip teeth from moving away from the end of the conical segment.

3. The fast-dissolving bridge plug according to claim 2, characterized in that, The locking device further includes a hoop, and a plurality of the locking push blocks are distributed circumferentially along the conical section to jointly form a wedge-shaped hole; the hoop is configured to clamp the plurality of locking push blocks circumferentially.

4. The fast-dissolving bridge plug according to claim 3, characterized in that, At least two of the locking push blocks have mounting grooves on their outer surfaces, and the hoop is located in the mounting groove.

5. The fast-dissolving bridge plug according to claim 1, characterized in that, The anchor body includes a plurality of anchor blocks arranged circumferentially along the bridge plug body, with gaps between adjacent anchor blocks and connecting ribs disposed in the gaps. The connecting ribs are configured to connect two adjacent anchor blocks and are configured to disconnect when the anchor body is subjected to an axial external force. Anchoring teeth are embedded on the outer surface of the anchoring block. Part of the anchoring teeth protrudes from the outer surface of the anchoring block, and the anchoring teeth have an inclined angle relative to the outer surface of the anchoring block.

6. The fast-dissolving bridge plug according to claim 5, characterized in that, The lower connector has a tapered stepped surface at one end near the anchor body, and the stepped surface is configured to support the anchor body; The lower connector is provided with a guide cone surface at the end opposite to the anchor body, the guide cone surface being configured to guide the bridge plug; and / or, it also includes a soluble ball, the soluble ball being configured to block the end of the through hole opposite to the lower connector.

7. The fast-dissolving bridge plug according to claim 1, characterized in that, It also includes a release mandrel and a pusher, wherein the release mandrel is a hollow structure and one end of the release mandrel has an external thread on its outer surface. The release mandrel is configured to pass through the through hole and the external thread is threadedly connected to the threaded hole of the lower connector. The push cylinder has a cylindrical structure and is located on the side of the push ring away from the locking device, and abuts against the push ring; the release mandrel and the push cylinder together form the adapter mandrel.

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