A flexible drill pipe plug

Abstract

The present invention provides a flexible drill pipe plug, which belongs to the technical field of tail pipe cementing in oil and gas fields. The plug comprises a core body made of elastic plastic material, a top cover is provided above the core body, a shrinkage tube and a socket are provided in sequence below the core body, and a colloid is commonly sleeved on the outside of the core body, the top cover and the shrinkage tube, the interior of the core body is sequentially penetrated by a plurality of frustum-shaped internal cavities along the axial direction from bottom to top, the interior of the core body is sequentially provided with a plurality of expansion joints made of hard metal material along the axial direction, the number of the expansion joints is consistent with the number of the internal cavities, the expansion joints of each level are slidably arranged in the expansion joints of the next level, the height of the expansion joints of each level are equal, and the expansion joints of each level correspond to the corresponding internal cavities one by one, when the flexible drill pipe plug passes through a continuous oil pipe wound on a large roller, the core body elastically bends along the curved continuous oil pipe without permanent deformation.

Description

Technical Field

[0001] The invention belongs to the technical field of tail pipe cementing in oil and gas fields, and particularly relates to a flexible drill pipe rubber plug. Background Art

[0002] In oil and gas field drilling operations, liner cementing has become the preferred technology for deep and ultra-deep well cementing due to its significant cost-effectiveness. The liner hanger plays a crucial role in this process, and the drill pipe plug, an essential component of the hanger, effectively isolates the displacement fluid from the cement slurry and drives cement slurry injection. Failure of the drill pipe plug directly leads to failure of the cementing operation. During this process, the drill pipe plug must be precisely released, allowing the bottom of its metal frame to smoothly penetrate the through-hole of the liner plug, thereby achieving a composite self-locking connection between the drill pipe plug and the liner plug.

[0003] In the existing technology system, drill pipe plugs are made by compounding a metal skeleton with a rubber material with high wear resistance, oil resistance, and tear resistance through a precise injection vulcanization process under high temperature conditions. In order to significantly improve operational efficiency and quality, continuous tubing technology is widely used in cementing operations. However, continuous tubing is often wound on large rollers, and this part of the continuous tubing is in a curved shape. Traditional rigid drill pipe plugs are extremely susceptible to permanent deformation during the passage process, resulting in permanent damage, which brings great uncertainty to cementing operations. Therefore, there is a need for a flexible drill pipe plug that will not permanently deform when passing through the continuous tubing wrapped on large rollers, while greatly reducing running resistance and making cementing reliable and convenient. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the present invention aims to provide a flexible drill pipe plug.

[0005] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: a flexible drill pipe plug, characterized in that it includes a core body made of elastic plastic material, a top cover is provided on the top of the core body, a shrinkage tube and a socket are provided in sequence below the core body, and the core body, the top cover and the shrinkage tube are jointly sleeved with a colloid on the outside; the outside of the colloid is provided with multiple large rubber discs and small rubber discs.

[0006] Furthermore, the interior of the core body is provided with a plurality of frustum-shaped internal cavities in sequence from bottom to top along the axial direction, and the upper circular surface diameter of each level of internal cavity is larger than the lower circular surface diameter of the upper level of internal cavity, and the heights of all internal cavities are equal; the interior of the core body is provided with a plurality of expansion joints made of hard metal material in sequence along the axial direction, the number of expansion joints is consistent with the number of internal cavities, the expansion joints of each level are slidably arranged in the expansion joints of the next level, the height of each level of expansion joints is equal, and the expansion joints of each level correspond one-to-one to the corresponding internal cavity.

[0007] Furthermore, the upper and lower surfaces of the core body are respectively provided with an upper convex ring and a lower convex ring, the lower surface of the top cover is provided with an upper bite groove matching the upper convex ring, and the upper surface of the shrink tube is provided with a lower bite groove matching the lower convex ring.

[0008] Furthermore, the cylindrical surface of the core is provided with a plurality of annular grooves, and the inner cylindrical surface of the colloid is provided with a plurality of annular platforms respectively engaged with the annular grooves.

[0009] Furthermore, the outside of each telescopic joint is a frustum structure, and the frustum of the telescopic joint is consistent with the shape of the corresponding inner cavity. The telescopic joint is composed of a cylindrical surface and a cylindrical boss structure below the frustum. Slide grooves are provided around the cylindrical boss, and an inner sliding cylindrical surface is provided inside the telescopic joint. A neck hole with a diameter smaller than the inner sliding cylindrical surface is provided through the upper part of the inner sliding cylindrical surface. Four sliding bars are evenly and vertically provided on the inner wall of the inner sliding cylindrical surface. A plurality of blocking grooves are provided at the outer edge of the bottom of the cylindrical boss, and a plurality of blocking platforms are provided at the inner edge of the bottom of the cylindrical boss. The number of blocking grooves and blocking platforms is equal.

[0010] Furthermore, the cylindrical boss of each level of telescopic joint forms a sliding fit with the inner sliding cylindrical surface of the next level telescopic joint, and the four slide grooves of each level of telescopic joint respectively form a sliding fit with the four slide bars of the next level telescopic joint. The diameter of the cylindrical surface of each level of telescopic joint is consistent with the diameter of the neck hole of the next level telescopic joint, and the blocking groove of each level of telescopic joint is adapted to the blocking platform of the next level telescopic joint; four lock slide grooves are provided at the bottom of the cylindrical boss of the telescopic joint, and a lock slider is provided for sliding in the lock slide groove. A lock pin extending to the outside of the cylindrical boss is provided on the side of the lock slider, and a lock spring is connected between the lock slider and the inner wall of the lock slide groove. Four lock holes are provided between the conical surface and the inner sliding cylindrical surface of each level of telescopic joint, which are respectively adapted to the four lock pins on the next level telescopic joint.

[0011] Furthermore, a contraction cavity is provided inside the contraction cylinder, and a contraction neck hole with a diameter smaller than the contraction cavity is provided through the upper part of the contraction cavity, and the contraction cavity forms a sliding fit with the cylindrical boss of the lowest telescopic joint, and the diameter of the contraction neck hole is the same as the diameter of the cylindrical surface of the lowest telescopic joint. Four contraction slides are evenly provided on the inner wall of the contraction cavity of the contraction cylinder, and the four contraction slides respectively form a sliding fit with the slide groove of the lowest telescopic joint, and a contraction stop is provided inwardly at the bottom of the contraction cavity, which is adapted to the blocking groove of the lowest telescopic joint. Four limiting holes are provided through the contraction cavity, which are respectively adapted to the four locking pins on the lowest telescopic joint, and the height of the contraction cylinder is equal to the height of the telescopic joint.

[0012] Furthermore, an inner cover cavity is provided in the middle of the top cover, a top cover through hole is provided on the lower surface of the top cover which is connected to the inner cover cavity, four top cover slides are evenly provided on the inner wall of the inner cover cavity, a top lock strip is slidably provided in the four top cover slides, a round table is provided on the top lock strip, a top spring is connected between the inner wall of the inner cover cavity and the round table, a limit table is provided on the top lock strip at one end facing the central axis of the top cover, a top lock arc surface is provided on the top lock strip and located between the round table and the limit table; the top of the uppermost telescopic joint is provided with Top locking block, the diameter of the top locking block is equal to the diameter of the through hole of the top cover, four top locking grooves are evenly arranged on the cylindrical surface of the top locking block, which are used to clamp the four top locking strips respectively, and a locking inclined surface for driving the limit platform is provided on the upper part of the top locking block, and a through hole is provided in the top locking block along the axis; a sealing block is provided at the bottom of the inner sliding cylindrical surface of the uppermost telescopic joint, and a main spring is provided between the sealing block and the upper surface of the inner cover cavity of the top cover, and the main spring passes through the inner sliding cylindrical surface, neck hole and through hole of the top locking block of all telescopic joints.

[0013] Furthermore, the bottom of the socket is a circular inclined surface, and four socket slides are evenly arranged on the cylindrical surface of the socket and above the circular inclined surface. A drive slide is slidably provided in the four socket slides, and one end of the drive slide is an external drive inclined surface extending to the socket, and a limit block is provided on the upper part of the other end of the drive slide, and the limit block is located inside the socket, and a limit spring is connected between the socket and the drive slide, and a low limit plate is provided on the upper part of the limit block, and four limit grooves for clamping the limit block are evenly arranged on the lower surface of the low limit plate. The surface connection is provided with a connecting block, the upper surface of the connecting block is connected with a high limit disk, two side support plates are symmetrically provided on the side of the high limit disk, two arc rods are symmetrically provided between the two side support plates, side sliding seats are slidably provided on the arc rods, the side sliding seats are fixed on the inner wall of the socket, and arc springs are sleeved on the outside of the arc rods, and the two ends of the arc springs are respectively connected to the side support plates and the side sliding seats; a clamping platform is provided at the bottom of the sealing block, and a clamping hole for clamping the clamping platform is provided in the middle of the high limit disk, and the thickness of the clamping platform is less than the height of the connecting block.

[0014] Furthermore, the core body is made of elastic steel wire rope material, a circular hole connected to the core body is provided below the top cover, and a circular hole connected to the core body is provided above the shrinking cylinder.

[0015] The beneficial effects of the present invention compared with the prior art are as follows: (1) When the flexible drill pipe plug of the present invention passes through the continuous oil pipe wound on the large roller, the core body elastically bends along the curved continuous oil pipe, and the colloid also bends along with the core body, so the flexible drill pipe plug can smoothly pass through the curved section of the continuous oil pipe. When the flexible drill pipe plug reaches the straight section of the continuous oil pipe, the core body automatically returns to the straight state, and the colloid also returns to the straight state along with the core body, so the flexible drill pipe plug will not be permanently deformed.

[0016] (2) During the insertion of the flexible drill pipe plug of the present invention into the tail pipe plug, the socket first enters the through hole of the tail pipe plug, and then the upper chord edge of the tail pipe plug contacts the drive slide and the drive inclined surface, so that the four drive slides are squeezed to slide toward the center at the same time, the clamping hole is separated from the clamping table, and the main spring provides tension to pull the top telescopic joint upward. Finally, the socket, the shrinking cylinder, all the telescopic joints, the top locking block and the top cover are rigidly connected together. At the same time, the cone surface of the telescopic joint of each level is tightly fitted with the corresponding inner cavity, and the top surface of the telescopic joint is also in contact with the top surface on the inner cavity, so that the core body no longer undergoes elastic bending. Therefore, under the action of the oil well pressure, the flexible drill pipe plug can smoothly enter the tail pipe plug.

[0017] (3) The four driving slides of the present invention will not contact the inner wall of the continuous oil pipe at the same time, so the four limit grooves on the low limit plate will not lose their limits at the same time. When the socket touches the continuous oil pipe, the limit spring provides elastic force to reinsert the limit block on the driving slide into the corresponding limit groove. Therefore, the flexible drill pipe plug has an anti-accidental touch function when passing through the continuous oil pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the front side of the present invention.

[0019] Figure 2 It is a schematic structural diagram of the overall cross-section of the first embodiment of the present invention.

[0020] Figure 3 It is a structural diagram of the connection between the top cover, the shrink tube and the socket of the present invention.

[0021] Figure 4 It is a structural schematic diagram of the colloid cross section of the present invention.

[0022] Figure 5 It is a structural schematic diagram of the core cross section of the present invention.

[0023] Figure 6 It is a structural schematic diagram of the expansion joint connection of the present invention.

[0024] Figure 7 It is a schematic structural diagram of the telescopic joint of the present invention when viewed from above.

[0025] Figure 8 It is a schematic structural diagram of the telescopic joint of the present invention when viewed from above.

[0026] Figure 9 yes Figure 8 A partial enlarged view of point B in the middle.

[0027] Figure 10 It is a schematic structural diagram of the shrinking tube of the present invention when viewed from above.

[0028] Figure 11 It is a schematic structural diagram of the shrinking tube of the present invention when viewed from above.

[0029] Figure 12 It is a structural schematic diagram of the cross section of the top cover of the present invention.

[0030] Figure 13 It is a structural schematic diagram of the installation of the top lock strip of the present invention.

[0031] Figure 14 It is a structural schematic diagram of the top locking strip of the present invention.

[0032] Figure 15 It is a structural schematic diagram of the installation of the top locking block of the present invention.

[0033] Figure 16 It is a structural diagram of the sealing block and the card table installation of the present invention.

[0034] Figure 17 for Figure 2 A partial enlarged view of point A in the middle.

[0035] Figure 18 It is a structural schematic diagram of the socket of the present invention.

[0036] Figure 19 It is a schematic diagram of the internal structure of the socket of the present invention.

[0037] Figure 20 It is a structural schematic diagram of the installation of the low limit plate of the present invention.

[0038] Figure 21 It is a structural schematic diagram of the explosion installation of the low limit plate of the present invention.

[0039] Figure 22 It is a structural schematic diagram of the installation of the high limit plate, side support plates and arc rods of the present invention.

[0040] Figure 23 It is a schematic structural diagram of the overall cross section of the second embodiment of the present invention.

[0041] Figure numbers: 1-core; 101-inner cavity; 102-upper convex ring; 103-lower convex ring; 104-ring groove; 2-top cover; 201-upper bite groove; 202-inner cover cavity; 203-top cover through hole; 204-top cover slide; 3-shrinkage cylinder; 301-lower bite groove; 302-shrinkage cavity; 303-shrinkage neck hole; 304-shrinkage slide; 305-limiting hole; 306-shrinkage stop; 4-socket; 401-circular inclined surface; 402-socket slide; 5-colloid; 501-ring platform; 6-expansion joint; 601-cone surface; 602-cylindrical surface; 603-cylindrical boss; 604-slide; 605-inner sliding cylindrical surface; 606-neck hole; 607-slide; 608- Blocking groove; 609-blocking platform; 610-locking slide; 611-locking hole; 7-locking slider; 8-locking pin; 9-locking spring; 10-top locking strip; 1001-round platform; 1002-limiting platform; 1003-top locking arc surface; 11-top spring; 12-top locking block; 1201-top locking groove; 1202-locking inclined surface; 1203-through hole; 13-sealing block; 14-main spring; 15-driving slide; 1501-driving inclined surface; 16-limiting block; 17-limiting spring; 18-low limit plate; 19-limiting groove; 20-connecting block; 21-high limit plate; 2101-clamping hole; 22-side support plate; 23-arc rod; 24-side sliding seat; 25-arc spring; 26-clamping platform. DETAILED DESCRIPTION

[0042] In the present invention, unless otherwise specified, directions such as "up" and "down" are generally used with respect to the directions shown in the drawings, or with respect to the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "left" and "right" are generally used with respect to the left and right shown in the drawings; "inside" and "outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directions are not used to limit the present invention.

[0043] Example 1: Please refer to Figure 1-Figure 22 Structural schematic diagram, the present invention provides the following technical solutions: a flexible drill pipe plug, comprising a core 1 made of elastic material, the optional elastic material is polycarbonate, a top cover 2 is provided above the core 1, a shrinkage tube 3 and a socket 4 are provided below the core 1 in sequence, the core 1, the top cover 2 and the shrinkage tube 3 are commonly sleeved with a colloid 5 on the outside, and a plurality of large and small rubber discs for sealing with the tail pipe plug are provided on the outside of the colloid 5.

[0044] Specifically, the upper part of the colloid 5 overlaps with the top cover 2, and the lower part of the colloid 5 overlaps with the shrink tube 3. When the flexible drill pipe plug and the tail pipe plug are self-locked, the socket 4 first enters the tail pipe plug; when the flexible drill pipe plug passes through the coiled tubing wrapped on the large roller, the core 1 elastically bends along the curved coiled tubing, and the colloid 5 also bends with the core 1, so the flexible drill pipe plug can smoothly pass through the curved section of the coiled tubing. When the flexible drill pipe plug reaches the straight section of the coiled tubing, the core 1 automatically returns to a straight state, and the colloid 5 also returns to a straight state with the core 1, so the flexible drill pipe plug will not be permanently deformed.

[0045] Considering that a fully flexible drill pipe plug solution can solve the deformation problem during operation in coiled tubing, at the critical moment of forming a composite self-locking structure with the liner plug, the purely flexible drill pipe plug may bend under the action of oil well pressure, making it difficult to smoothly embed into the liner plug. Therefore, at the moment of contact between the drill pipe plug and the liner plug, the drill pipe plug must be able to instantly convert to a rigid state to ensure that it can accurately complete the self-locking process.

[0046] The interior of the core 1 is provided with a plurality of truncated cone-shaped inner cavities 101 in sequence from bottom to top along the axial direction, and the upper circular diameter of each level of inner cavity 101 is larger than the lower circular diameter of the previous level of inner cavity 101, and the heights of all inner cavities 101 are equal.

[0047] The upper surface and lower surface of the core body 1 are respectively provided with an upper convex ring 102 and a lower convex ring 103, the lower surface of the top cover 2 is provided with an upper bite groove 201 matching the upper convex ring 102, and the upper surface of the shrinking tube 3 is provided with a lower bite groove 301 matching the lower convex ring 103, so that the connection between the core body 1 and the top cover 2, and the connection between the core body 1 and the shrinking tube 3 are more firm.

[0048] The cylindrical surface of the core 1 is provided with a plurality of annular grooves 104, and the inner cylindrical surface of the colloid 5 is provided with a plurality of annular platforms 501 respectively engaging with the annular grooves 104, so that the colloid 5 which is sleeved together with the core 1, the top cover 2 and the outer part of the shrink tube 3 is not easy to fall off.

[0049] The interior of the core 1 is provided with a plurality of expansion joints 6 made of hard metal material in sequence along the axial direction. The optional hard metal material is a hard alloy material with tungsten added. The number of expansion joints 6 is consistent with the number of internal cavities 101. The expansion joints 6 of each level are slidably arranged in the expansion joints 6 of the next level. The height of the expansion joints 6 of each level is equal, and the expansion joints 6 of each level correspond one-to-one to the corresponding internal cavity 101. The outside of each telescopic joint 6 is a frustum surface 601 structure, and the frustum surface 601 of the telescopic joint 6 is consistent with the shape of the corresponding inner cavity 101. The telescopic joint 6 is composed of a cylindrical surface 602 and a cylindrical boss 603 structure below the frustum surface 601. The cylindrical boss 603 is provided with a sliding groove 604 around it, and the interior of the telescopic joint 6 is provided with an inner sliding cylindrical surface 605. The upper part of the inner sliding cylindrical surface 605 is penetrated by a neck hole 606 with a diameter smaller than the inner sliding cylindrical surface 605. Four sliding bars 607 are evenly and vertically provided on the inner wall of the inner sliding cylindrical surface 605. A plurality of blocking grooves 608 are provided at the outer edge of the bottom of the cylindrical boss 603, and a plurality of blocking platforms 609 are provided at the inner edge of the bottom of the cylindrical boss 603. The number of blocking grooves 608 and blocking platforms 609 is equal.

[0050] The cylindrical boss 603 of each telescopic section 6 forms a sliding fit with the inner sliding cylindrical surface 605 of the next telescopic section 6, and the four sliding grooves 604 of each telescopic section 6 form a sliding fit with the four sliding bars 607 of the next telescopic section 6, respectively, to ensure that the telescopic section 6 only slides up and down without rotating. The diameter of the cylindrical surface 602 of each telescopic section 6 is consistent with the diameter of the neck hole 606 of the next telescopic section 6, and the blocking groove 608 of each telescopic section 6 is adapted to the blocking platform 609 of the next telescopic section 6. When all telescopic sections 6 slide to the lower position, the cylindrical boss 603 of each telescopic section 6 slides to a position flush with the cylindrical boss 603 of the next telescopic section 6, and the blocking groove 608 of each telescopic section 6 enters the corresponding blocking platform 609 of the next telescopic section 6, preventing the telescopic section 6 from sliding out from the bottom of the next telescopic section 6. Since the heights of all telescopic sections 6 are comparable, each telescopic section 6 slides into the interior of the next telescopic section 6. When all the telescopic joints 6 slide to the upper position, the upper surface of the cylindrical boss 603 of each level of telescopic joint 6 contacts the upper surface of the inner sliding cylindrical surface 605 of the next level of telescopic joint 6, thereby preventing each level of telescopic joint 6 from sliding out from above the telescopic joint 6 of the next level, and the cylindrical surface 602 of each level of telescopic joint 6 slides into the neck hole 606 of the next level of telescopic joint 6, making the connection between the two adjacent telescopic joints 6 more secure; at the same time, the frustum surface 601 of the telescopic joint 6 of each level fits tightly with the corresponding inner cavity 101, and the top surface of the telescopic joint 6 also contacts and fits with the top surface on the inner cavity 101, so that the core 1 no longer undergoes elastic bending.

[0051] Taking into account that when all the telescopic joints 6 slide to the upper position, the telescopic joint 6 needs to stop sliding down, four locking grooves 610 are provided at the bottom of the cylindrical boss 603 of the telescopic joint 6, and a locking slider 7 is provided for sliding in the lock groove 610. A locking pin 8 extending to the outside of the cylindrical boss 603 is provided on the side of the lock slider 7. A locking spring 9 is connected between the lock slider 7 and the inner wall of the lock groove 610. Four locking holes 611 are provided between the conical surface 601 and the inner sliding cylindrical surface 605 of each level of the telescopic joint 6, which are respectively adapted to the four locking pins 8 on the next level of the telescopic joint 6.

[0052] Specifically, when the telescopic section 6 is in the lower position, the locking pin 8 on each level of the telescopic section 6 contacts the inner sliding cylindrical surface 605 of the next level of the telescopic section 6, so the locking pin 8 does not pop out from the lock slide groove 610, and the locking spring 9 is in a compressed state; when the telescopic section 6 moves to the upper position, the locking pin 8 on each level of the telescopic section 6 coincides with the locking hole 611 of the next level of the telescopic section 6, and the locking spring 9 provides elastic force to make the locking pin 8 on each level of the telescopic section 6 inserted into the locking hole 611 of the next level of the telescopic section 6, wherein the end face of the locking pin 8 is a chamfered surface, which facilitates the locking pin 8 to be inserted into the corresponding locking hole 611, so the two adjacent telescopic sections 6 are locked together, thereby preventing the telescopic section 6 from sliding downward.

[0053] The cam 304 of the first expansion joint 302 is provided with a plurality of expansion joints 306, and the expansion joint 306 is provided with a plurality of expansion joints 307.

[0054] Specifically, when the lowest telescopic section 6 is in the lower position, the lower surface of the lowest telescopic section 6 is flush with the lower surface of the contraction tube 3, and the blocking groove 608 of the lowest telescopic section 6 enters into the contraction stop 306 corresponding to the contraction tube 3, preventing the lowest telescopic section 6 from sliding out from the bottom of the contraction tube 3, that is, the lowest telescopic section 6 slides to the inside of the contraction tube 3, so when all telescopic sections 6 are in the lower position, all telescopic sections 6 can be located in the contraction cavity 302 of the contraction tube 3, so all telescopic sections 6 are no longer in contact with the corresponding inner cavity 101, and the core 1 is in an elastic state. When the lowest telescopic section 6 slides to the upper position, the upper surface of the cylindrical boss 603 of the lowest telescopic section 6 contacts the upper surface of the contraction cavity 302 of the contraction tube 3, thereby preventing the lowest telescopic section 6 from sliding out of the contraction tube 3. The cylindrical surface 602 of the lowest telescopic section 6 slides into the contraction neck hole 303, making the connection between the lowest telescopic section 6 and the contraction tube 3 more secure, and the frustum surface 601 of the lowest telescopic section 6 fits tightly with the corresponding internal cavity 101. At the same time, consistent with the above principle, the locking pin 8 on the lowest telescopic section 6 is inserted into the limiting hole 305 of the contraction tube 3.

[0055] Considering that when the telescopic joint 6 is in the upper position, in order to ensure that the drill pipe plug no longer bends, the uppermost telescopic joint 6 needs to be connected to the top cover 2. Therefore, an inner cover cavity 202 is provided in the middle of the top cover 2, and a top cover through hole 203 is provided on the lower surface of the top cover 2 that penetrates the inner cover cavity 202. Four top cover slideways 204 are evenly provided on the inner wall of the inner cover cavity 202. A top locking strip 10 is slidably provided in each of the four top cover slideways 204. A round table 1001 is provided on the top locking strip 10. A top spring 11 is connected between the inner wall of the inner cover cavity 202 and the round table 1001. A limit table 1002 is provided on the top locking strip 10 at one end of the top locking strip 10 facing the central axis of the top cover 2. A top locking arc surface 1003 is provided on the top locking strip 10 and located between the round table 1001 and the limit table 1002.

[0056] A top locking block 12 is provided at the top of the uppermost telescopic joint 6. The cylindrical arc surface of the top locking block 12 is consistent with the side curvature of the limit platform 1002. The diameter of the top locking block 12 is equal to the diameter of the top cover through hole 203. Four top locking grooves 1201 are evenly provided on the cylindrical surface of the top locking block 12, which are used to clamp the four top locking strips 10 respectively. A locking inclined surface 1202 for driving the limit platform 1002 is provided on the upper part of the top locking block 12, and a through hole 1203 is provided in the top locking block 12 along the axis.

[0057] Specifically, when all the telescopic joints 6 slide to the upper position, the top locking block 12 is inserted into the top cover through hole 203, wherein the locking inclined surface 1202 facilitates the insertion of the top locking block 12, and during the insertion process of the top locking block 12, the locking inclined surface 1202 contacts the top locking arc surface 1003, driving the top locking bar 10 to move outward, and the top spring 11 compresses and accumulates force. When the top locking arc surface 1003 of the top locking bar 10 coincides with the top locking groove 1201, the top spring 11 provides elastic force, so that the top locking arc surface 1003 of the top locking bar 10 is inserted into the top locking groove 1201, and the limit platform 1002 contacts the cylindrical arc surface of the top locking block 12, so a rigid connection is formed between the topmost telescopic joint 6, the top locking block 12 and the top cover 2.

[0058] A sealing block 13 is provided at the bottom of the inner sliding cylindrical surface 605 of the uppermost telescopic joint 6, and a main spring 14 is provided between the sealing block 13 and the upper surface of the inner cover cavity 202 of the top cover 2. The main spring 14 passes through the inner sliding cylindrical surface 605, the neck hole 606 and the through hole 1203 of the top locking block 12 of all telescopic joints 6. When all telescopic joints 6 are in the lower position, the main spring 14 is in a stretched and force-storing state, providing power for the telescopic joint 6 to move to the upper position.

[0059] The bottom of the socket 4 is a circular inclined surface 401, and four socket slideways 402 are evenly arranged on the cylindrical surface of the socket 4 and above the circular inclined surface 401. A drive slide 15 is slidably provided in the four socket slides 402. One end of the drive slide 15 is an external drive inclined surface 1501 extending to the socket 4, and a limit block 16 is provided on the upper part of the other end of the drive slide 15, and the limit block 16 is located inside the socket 4. A limit spring 17 is connected between the socket 4 and the drive slide 15, and a low limit plate 18 is provided on the upper part of the limit block 16. The lower surface of the low limit plate 18 is evenly provided with a limit spring 17. There are four limit grooves 19 for clamping the limit block 16. The upper surface of the low limit plate 18 is connected with a connecting block 20. The upper surface of the connecting block 20 is connected with a high limit plate 21. The side of the high limit plate 21 is symmetrically provided with two side support plates 22. Two arc rods 23 are symmetrically provided between the two side support plates 22. Side sliding seats 24 are slidably provided on the arc rods 23. The side sliding seats 24 are fixed on the inner wall of the socket 4. The outside of the arc rods 23 is provided with arc springs 25. The two ends of the arc springs 25 are respectively connected to the side support plates 22 and the side sliding seats 24.

[0060] A clamping platform 26 is provided at the bottom of the sealing block 13 , and a clamping hole 2101 for clamping the clamping platform 26 is provided in the middle of the high limit plate 21 , and the thickness of the clamping platform 26 is smaller than the height of the connecting block 20 .

[0061] Specifically, when the telescopic joint 6 is in the lower position, the clamping platform 26 is inserted into the clamping hole 2101, and the clamping hole 2101 clamps and locks the clamping platform 26. When the drill pipe plug is inserted into the liner plug, the circular bevel 401 of the socket 4 facilitates the overlap of the socket 4 and the through hole of the liner plug, and the socket 4 enters the through hole of the liner plug. Subsequently, the upper chord edge of the liner plug contacts the drive slide 15 and the drive bevel 1501, thereby simultaneously squeezing the four drive slides 15 to slide toward the center. As a result, the four limit blocks 16 are simultaneously disengaged from the limit grooves 19. The arc spring 25 provides tension, causing the arc rod 23 to slide in the side sliding seat 24. Therefore, the high limit plate 21 rotates, and the clamping hole 2101 is disengaged from the clamping platform 26.

[0062] When the flexible drill pipe plug passes through the coiled tubing, the socket 4 will come into contact with the inner wall of the coiled tubing. Since the inner diameter of the coiled tubing is larger than the diameter of the socket 4, the four drive slides 15 on the socket 4 will not contact the inner wall of the coiled tubing at the same time. Therefore, the four limit grooves 19 on the low limit plate 18 will not lose their limits at the same time. After the socket 4 touches the coiled tubing, the limit spring 17 provides elastic force to reinsert the limit blocks 16 on the drive slides 15 into the corresponding limit grooves 19. Therefore, the flexible drill pipe plug has the function of preventing accidental touch when passing through the coiled tubing.

[0063] The working principle of this embodiment is as follows: when the flexible drill pipe plug is released into the coiled tubing, all telescopic sections 6 are in the lower position, the clamping platform 26 is inserted into the clamping hole 2101 of the high limit plate 21, and the clamping hole 2101 clamps and locks the clamping platform 26. The clamping platform 26, through the sealing block 13, puts the uppermost telescopic section 6 in the lower position. The blocking groove 608 of each telescopic section 6 enters the corresponding blocking platform 609 of the next telescopic section 6, preventing the telescopic section 6 from sliding out from under the next telescopic section 6. The blocking groove 608 of the lowest telescopic section 6 enters the corresponding contraction blocking platform 306 of the contraction tube 3, preventing the lowest telescopic section 6 from sliding out from under the contraction tube 3. Therefore, all telescopic sections 6 are located in the contraction cavity 302 of the contraction tube 3, and the telescopic sections 6 have no effect on the inner cavity 101. When the flexible drill pipe plug passes through the coiled tubing wrapped on a large roller, the core 1 elastically bends along the curved coiled tubing, and the colloid 5 also bends along with the core 1. Therefore, the flexible drill pipe plug can smoothly pass through the curved section of the coiled tubing. When the flexible drill pipe plug reaches the straight section of the coiled tubing, the core 1 automatically returns to a straight state, and the colloid 5 also returns to a straight state along with the core 1. Therefore, the flexible drill pipe plug will not be permanently deformed.

[0064] When the flexible drill pipe plug is inserted into the liner plug, the circular bevel 401 of the socket 4 facilitates the coincidence of the socket 4 with the through hole of the liner plug. The socket 4 first enters the through hole of the liner plug. Then, the upper chord edge of the liner plug contacts the driving slide 15 and the driving bevel 1501, so that the four driving slides 15 are squeezed to slide toward the center at the same time. Therefore, the four limit blocks 16 are disengaged from the limit grooves 19 at the same time. The arc spring 25 provides tension to make the arc rod 23 slide in the side sliding seat 24. Therefore, the high limit plate 21 rotates and the clamping hole 2101 is disengaged from the clamping platform 26.

[0065] The main spring 14 provides a pulling force to pull the top telescopic section 6 upward, and the cylindrical boss 603 of the top telescopic section 6 slides in the inner sliding cylindrical surface 605 of the next level. When the upper surface of the cylindrical boss 603 of the top telescopic section 6 contacts the upper surface of the inner sliding cylindrical surface 605 of the next level telescopic section 6, the top telescopic section 6 is prevented from sliding out from above the next level telescopic section 6. At the same time, the locking pin 8 on the top telescopic section 6 coincides with the locking hole 611 of the next level telescopic section 6. The locking spring 9 provides an elastic force to insert the locking pin 8 on the top telescopic section 6 into the locking hole 611 of the next level telescopic section 6, thereby rigidly connecting the top telescopic section 6 to the next level telescopic section 6. Based on the above principle, all telescopic sections 6 are rigidly connected together, and the bottom telescopic section 6 is rigidly connected to the contraction tube 3.

[0066] When the top telescopic section 6 moves to the upper position, the top locking block 12 is inserted into the top cover through hole 203, wherein the locking inclined surface 1202 facilitates the insertion of the top locking block 12, and during the insertion process of the top locking block 12, the locking inclined surface 1202 contacts the top locking arc surface 1003, driving the top locking bar 10 to move outward, and the top spring 11 compresses and accumulates force. When the top locking arc surface 1003 of the top locking bar 10 coincides with the top locking groove 1201, the top spring 11 provides elastic force, so that the top locking arc surface 1003 of the top locking bar 10 is inserted into the top locking groove 1201, and the limit platform 1002 contacts the cylindrical arc surface of the top locking block 12, so a rigid connection is formed between the top telescopic section 6, the top locking block 12 and the top cover 2.

[0067] In summary, the socket 4, the contraction tube 3, all the telescopic joints 6, the top locking block 12 and the top cover 2 are rigidly connected together. At the same time, the frustum surface 601 of the telescopic joint 6 of each level is tightly fitted with the corresponding inner cavity 101, and the top surface of the telescopic joint 6 is also in contact with the top surface of the inner cavity 101, so that the core 1 no longer undergoes elastic bending. Therefore, under the action of the oil well pressure, the flexible drill pipe plug can smoothly enter the tail pipe plug.

[0068] Example 2: Please refer to Figure 23Structural diagram, the present invention provides the following technical solutions: A flexible drill pipe plug includes a core 1 made of elastic material, with a top cover 2 provided above the core 1, and a shrinking tube 3 and a socket 4 provided below the core 1 in sequence. The core 1, top cover 2, and shrinking tube 3 are externally sleeved with a colloid 5, and the colloid 5 is externally provided with multiple large and small rubber discs. The core 1 is made of elastic steel wire rope material, and a circular hole is provided below the top cover 2 to connect to the core 1. The upper end of the core 1 extends into the circular hole below the top cover 2 for compression. A circular hole is provided above the shrinking tube 3 to connect to the core 1, and the lower end of the core 1 extends into the circular hole above the shrinking tube 3 for compression. When the flexible drill pipe plug passes through the coiled tubing wrapped on a large roller, the core 1 elastically bends along the curved coiled tubing, and the colloid 5 also bends along with the core 1. Therefore, the flexible drill pipe plug can smoothly pass through the curved section of the coiled tubing. When the flexible drill pipe plug reaches the straight section of the coiled tubing, the core 1 automatically returns to a straight state, and the colloid 5 also returns to a straight state along with the core 1. Therefore, the flexible drill pipe plug will not be permanently deformed.

[0069] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications based on the present invention to solve substantially the same technical problems and achieve substantially the same technical effects are all included in the scope of protection of the present invention.

Claims

1. A flexible drill pipe plug, characterized by: The invention comprises a core body (1) made of elastic material, a top cover (2) being provided above the core body (1), a shrinking tube (3) and a socket (4) being provided below the core body (1), a colloid (5) being sleeved on the outside of the core body (1), the top cover (2) and the shrinking tube (3), and a plurality of large and small colloid discs being provided on the outside of the colloid (5); The core (1) is provided with a plurality of truncated cone-shaped internal cavities (101) running through the core (1) in sequence from bottom to top along the axial direction, and the upper circular surface diameter of each level of internal cavity (101) is larger than the lower circular surface diameter of the previous level of internal cavity (101), and the heights of all the internal cavities (101) are equal; The core (1) is provided with a plurality of telescopic joints (6) made of hard metal material in sequence along the axial direction. The number of the telescopic joints (6) is consistent with the number of the internal cavities (101). The telescopic joints (6) of each level are slidably arranged in the telescopic joints (6) of the next level. The height of the telescopic joints (6) of each level is equal, and the telescopic joints (6) of each level correspond to the corresponding internal cavities (101) one by one.

2. The flexible drill pipe plug according to claim 1, characterized in that: The upper surface and lower surface of the core body (1) are respectively provided with an upper convex ring (102) and a lower convex ring (103); the lower surface of the top cover (2) is provided with an upper bite groove (201) matching the upper convex ring (102); and the upper surface of the shrink tube (3) is provided with a lower bite groove (301) matching the lower convex ring (103).

3. The flexible drill pipe plug according to claim 1, characterized in that: The cylindrical surface of the core (1) is provided with a plurality of annular grooves (104), and the inner cylindrical surface of the colloid (5) is provided with a plurality of annular platforms (501) respectively engaged with the annular grooves (104).

4. The flexible drill pipe plug according to claim 1, characterized in that: The outside of each telescopic joint (6) is a cone-shaped surface (601) structure. The cone-shaped surface (601) of the telescopic joint (6) is consistent with the shape of the corresponding inner cavity (101). The telescopic joint (6) is sequentially provided with a cylindrical surface (602) and a cylindrical boss (603) structure below the cone-shaped surface (601). The cylindrical boss (603) is provided with a sliding groove (604) around it. The interior of the telescopic joint (6) is provided with an inner sliding cylindrical surface (605). The upper part of the inner sliding cylindrical surface (605) is provided with a neck hole (606) with a diameter smaller than that of the inner sliding cylindrical surface (605). Four sliding strips (607) are evenly and vertically provided on the inner wall of the inner sliding cylindrical surface (605). A plurality of blocking grooves (608) are provided at the outer edge of the bottom of the cylindrical boss (603). A plurality of blocking platforms (609) are provided at the inner edge of the bottom of the cylindrical boss (603). The number of blocking grooves (608) and blocking platforms (609) is equal.

5. The flexible drill pipe plug according to claim 4, characterized in that: The cylindrical boss (603) of each telescopic section (6) forms a sliding fit with the inner sliding cylindrical surface (605) of the next telescopic section (6), the four sliding grooves (604) of each telescopic section (6) respectively form a sliding fit with the four sliding strips (607) of the next telescopic section (6), the diameter of the cylindrical surface (602) of each telescopic section (6) is consistent with the diameter of the neck hole (606) of the next telescopic section (6), and the blocking groove (608) of each telescopic section (6) is adapted to the blocking platform (609) of the next telescopic section (6); Four locking grooves (610) are provided at the bottom of the cylindrical boss (603) of the telescopic joint (6), a locking slider (7) is slidably provided in the locking groove (610), a locking pin (8) extending to the outside of the cylindrical boss (603) is provided on the side of the locking slider (7), a locking spring (9) is connected between the locking slider (7) and the inner wall of the locking groove (610), and four locking holes (611) are respectively adapted to the four locking pins (8) on the next telescopic joint (6) through the conical surface (601) and the inner sliding cylindrical surface (605) of each telescopic joint (6).

6. The flexible drill pipe plug according to claim 5, characterized in that: The shrinking tube (3) is provided with a shrinking cavity (302) inside, and a shrinking neck hole (303) having a diameter smaller than that of the shrinking cavity (302) is provided through the upper part of the shrinking cavity (302). The shrinking cavity (302) forms a sliding fit with the cylindrical boss (603) of the lowest telescopic section (6). The diameter of the shrinking neck hole (303) is the same as the diameter of the cylindrical surface (602) of the lowest telescopic section (6). Four shrinking slide bars (304) are evenly provided on the inner wall of the shrinking cavity (302) of the shrinking tube (3). ), four retractable slide bars (304) respectively form a sliding fit with the slide groove (604) of the lowest telescopic section (6), and a retractable stopper (306) adapted to the blocking groove (608) of the lowest telescopic section (6) is provided inwardly at the bottom of the retractable cavity (302), and four limiting holes (305) respectively adapted to the four locking pins (8) on the lowest telescopic section (6) are provided through the retractable cavity (302), and the height of the retractable cylinder (3) is equal to the height of the telescopic section (6).

7. The flexible drill pipe plug according to claim 6, characterized in that: An inner cover cavity (202) is provided in the middle of the top cover (2), a top cover through hole (203) that penetrates the inner cover cavity (202) is provided on the lower surface of the top cover (2), four top cover slideways (204) are evenly provided on the inner wall of the inner cover cavity (202), a top locking strip (10) is slidably provided in each of the four top cover slideways (204), a round platform (1001) is provided on the top locking strip (10), a top spring (11) is connected between the inner wall of the inner cover cavity (202) and the round platform (1001), one end of the top locking strip (10) facing the central axis of the top cover (2) is a limiting platform (1002), and a top locking arc surface (1003) is provided on the top locking strip (10) and located between the round platform (1001) and the limiting platform (1002); A top locking block (12) is provided on the top of the uppermost telescopic section (6), the diameter of the top locking block (12) being equal to the diameter of the top cover through hole (203), four top locking grooves (1201) for respectively clamping four top locking strips (10) are evenly provided on the cylindrical surface of the top locking block (12), a locking inclined surface (1202) for driving the limit platform (1002) is provided on the upper portion of the top locking block (12), and a through hole (1203) is provided in the top locking block (12) along the axis. A sealing block (13) is provided at the bottom of the inner sliding cylindrical surface (605) of the uppermost telescopic joint (6), and a main spring (14) is provided between the sealing block (13) and the upper surface of the inner cover cavity (202) of the top cover (2). The main spring (14) passes through the inner sliding cylindrical surface (605), the neck hole (606) and the through hole (1203) of the top locking block (12) of all telescopic joints (6).

8. The flexible drill pipe plug according to claim 7, characterized in that: The bottom of the socket (4) is a circular inclined surface (401), and four socket slideways (402) are evenly arranged on the cylindrical surface of the socket (4) and located above the circular inclined surface (401). A driving slide bar (15) is slidably provided in each of the four socket slideways (402), and one end of the driving slide bar (15) is an external driving inclined surface (1501) extending to the socket (4). A limit block (16) is provided on the upper part of the other end of the driving slide bar (15), and the limit block (16) is located inside the socket (4). A limit spring (17) is connected between the socket (4) and the driving slide bar (15), and a low limit plate (18) is provided on the upper part of the limit block (16). The lower surface of the low limit plate (18) is provided. The surface is evenly provided with four limiting grooves (19) for clamping the limiting block (16), the upper surface of the low limiting plate (18) is connected with a connecting block (20), the upper surface of the connecting block (20) is connected with a high limiting plate (21), the side of the high limiting plate (21) is symmetrically provided with two side support plates (22), two arc rods (23) are symmetrically provided between the two side support plates (22), the arc rods (23) are slidably provided with side sliding seats (24), the side sliding seats (24) are fixedly provided on the inner wall of the socket (4), the outer side of the arc rods (23) are sleeved with arc springs (25), and the two ends of the arc springs (25) are respectively connected to the side support plates (22) and the side sliding seats (24); A clamping platform (26) is provided at the bottom of the sealing block (13), a clamping hole (2101) for clamping the clamping platform (26) is provided in the middle of the high limit plate (21), and the thickness of the clamping platform (26) is less than the height of the connecting block (20).

9. The flexible drill pipe plug according to claim 1, characterized in that: The core body (1) is made of elastic steel wire rope material, a circular hole connected to the core body (1) is provided below the top cover (2), and a circular hole connected to the core body (1) is provided above the shrinking cylinder (3).

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