Composite expansion cone system for expansion screen pipe

Abstract

The invention relates to the technical field of expansion cone tools, in particular to a composite expansion cone system for an expansion screen pipe. The problems that in the prior art, due to the fact that the outer diameter of an expansion cone is small, the expansion rate of an expansion screen pipe is not enough, due to the fact that the outer diameter of the expansion cone is large, the expansion cone can not be lowered to a designated position, and even if the expansion cone with the larger outer diameter is lowered to the designated position smoothly, the expansion screen pipe cannot be expanded are solved. However, due to the fact that the expansion rate is increased, larger expansion resistance can be brought, and the risk that the expansion cone is clamped is increased. According to the composite expansion cone system for the expansion screen pipe, the expansion rate of an expansion pipe column is increased as much as possible through a composite expansion cone part, the risk of clamping an expansion cone is reduced, and rebound of the pipe column after expansion is reduced so as to guarantee that the designed expansion rate can be achieved; the variable-diameter cone is of a split type structure, when the expansion cone is clamped, the split expansion cone can be lifted up and expanded again, the limitation of the inner diameter of the hanger on the outer diameter of the expansion cone is reduced to a certain extent, and the purpose of achieving the larger expansion rate is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of expansion cone tools, and in particular to a composite expansion cone system for expanding screen pipes. Background Art

[0002] The expansion screen pipe technology is considered to be one of the most promising technologies in the oil drilling and production industry in the 21st century. This technology is to lower the pipe string (including solid casing and slotted pipe) to the bottom of the well, and by mechanical or hydraulic means, from top to bottom or from bottom to top, through tension or pressure, the pipe string is permanently plastically deformed, so as to achieve the purpose of expanding the wellbore or the inner diameter of the production pipe string. The expansion screen pipe technology can be widely used in operations such as drilling, well completion, oil production, and workover. Moreover, if the outer diameter of the expansion cone is small, the expansion rate of the expansion screen pipe is insufficient, and the outer wall of the expansion screen pipe cannot fit the wellbore after expansion, reducing the use effect of the expansion cone; if the outer diameter of the expansion cone is large, the expansion cone may not be able to be lowered to the designated position due to the inner diameter of the pipe string. Even if the expansion cone with a larger outer diameter is successfully lowered to the designated position, due to the increase in the expansion rate, a greater expansion resistance will be brought, increasing the risk of the expansion cone getting stuck. In addition, due to the excessive expansion resistance, there may be a risk of the expansion cone getting stuck or even jammed during the construction process. Once the expansion cone is jammed, it will not be able to be pulled up or lowered, which will seriously affect the normal progress of the construction. Therefore, a tool, method or system that can solve the foregoing problems is needed. Summary of the Invention

[0003] The purpose of the present invention is to provide a composite expansion cone system for expanding screen pipes to solve the problems in the prior art, including insufficient expansion rate of the expansion screen pipe due to a small outer diameter of the expansion cone, the expansion cone may not be able to be lowered to the designated position due to a large outer diameter of the expansion cone, and even if the expansion cone with a larger outer diameter is successfully lowered to the designated position, but due to the increase in the expansion rate, a greater expansion resistance is brought, resulting in an increased risk of the expansion cone getting stuck.

[0004] In order to solve the above technical problems, the technical solution provided by the present invention is as follows:

[0005] The present invention provides a composite expansion cone system for expanding screen pipes, including: a release central pipe, a diameter-preserving expansion cone, a diameter-preserving expansion cone connecting sleeve, a spring, a connecting sleeve, an upper cone mandrel, a limit cap, an upper cone sleeve, a lower cone mandrel, a split expansion cone, a lower cone sleeve, and a starting expansion cone; wherein, the split expansion cone includes an embedded cone and an expanding cone.

[0006] The diameter-preserving expansion cone is assembled outside the release central pipe.

[0007] The diameter-preserving expansion cone connecting sleeve is connected to the release central pipe, and the diameter-preserving expansion cone is connected to the diameter-preserving expansion cone connecting sleeve.

[0008] The connecting sleeve is connected to the lower end of the releasing central pipe, and the spring is assembled in the lower end hole of the releasing central pipe;

[0009] The upper cone mandrel is connected to the inner part of the lower end of the connecting sleeve,

[0010] The upper cone sleeve is connected to the outer part of the lower end of the connecting sleeve;

[0011] The limiting compression cap and the lower part of the spring are assembled in the end hole of the upper cone mandrel, and the limiting compression cap is connected below the spring;

[0012] The embedding cone is assembled between the upper cone mandrel and the upper cone sleeve, and the embedding cone is connected through the rectangular hole at the lower end of the upper cone mandrel;

[0013] The lower cone mandrel is connected to the threaded hole at the lower end of the limiting compression cap and is assembled in the lower end hole of the upper cone mandrel, and the limiting compression cap can slide along the axis direction of the lower end hole of the upper cone mandrel;

[0014] The diameter-expanding cone is assembled in the rectangular hole at the lower end of the lower cone mandrel;

[0015] The lower cone sleeve is connected to the lower end of the lower cone mandrel;

[0016] The starting expansion cone is assembled outside the lower cone sleeve;

[0017] When the split expansion cone is in the diameter-reduced state, the distance between the intermediate rectangular holes of the upper cone mandrel and the intermediate rectangular holes of the lower cone mandrel becomes larger, and the contact surface between the embedding cone and the diameter-expanding cone decreases;

[0018] When the split expansion cone is in the diameter-expanded state, the distance between the intermediate rectangular holes of the upper cone mandrel and the intermediate rectangular holes of the lower cone mandrel becomes smaller, the contact surface between the embedding cone and the diameter-expanding cone increases, and the embedding cone and the diameter-expanding cone are engaged.

[0019] Further, the composite expansion cone system for expanding the screen pipe further includes a spring seat;

[0020] The spring seat is assembled in the lower end hole of the releasing central pipe;

[0021] The spring seat is connected above the spring.

[0022] Further, the composite expansion cone system for expanding the screen pipe further includes a limit pin;

[0023] The limit pin passes through the threaded hole at the lower end of the upper cone mandrel and is connected to the lower cone mandrel.

[0024] Further, the composite expansion cone system for expanding the screen pipe further includes a snap ring;

[0025] A snap ring is assembled in the U-shaped groove on the embedded cone;

[0026] A snap ring is assembled in the U-shaped groove on the diameter-expanded cone.

[0027] Furthermore, the composite expansion cone system for expanding a screen pipe further includes a sealing sleeve;

[0028] The sealing sleeve is connected to the inside of the lower end of the lower cone mandrel.

[0029] Furthermore, the composite expansion cone system for expanding a screen pipe further includes an upper joint, a release pawl spring sleeve, a release shear pin, and a release limit sleeve;

[0030] The upper joint is connected to the release pawl spring sleeve through a thread at the lower end;

[0031] The release shear pin is connected to the release limit sleeve through the upper threaded hole of the upper joint.

[0032] Furthermore, the composite expansion cone system for expanding a screen pipe further includes a guide head;

[0033] The guide head is connected to the lower end of the lower cone sleeve.

[0034] Furthermore, the composite expansion cone system for expanding a screen pipe further includes a first cleaning hole;

[0035] The first cleaning hole is provided on the guide head.

[0036] Furthermore, the composite expansion cone system for expanding a screen pipe further includes a second cleaning hole 24;

[0037] The second cleaning hole is also provided on the guide head 22.

[0038] Furthermore, the composite expansion cone system for expanding a screen pipe further includes a third cleaning hole;

[0039] The third cleaning hole is provided on the lower cone mandrel 14.

[0040] Based on the above technical solutions, the technical effects that the present invention can achieve are as follows:

[0041] The composite expansion cone system for expanding screen pipe provided by the present invention is that when the lower cone sleeve is not subjected to force, the entire petal expansion cone is in a reduced diameter state, and the embedded cone and the expanding cone are respectively limited in circumferential outward displacement due to the increase in the distance between the rectangular holes between the upper cone core shaft and the lower cone core shaft, and the upper cone sleeve and the lower cone sleeve limit the circumferential outward displacement, resulting in a reduction in the contact surface between the embedded cone and the expanding cone, the embedded cone moves downward along the cone surface of the upper cone core shaft, and the expanding cone moves toward the axis accordingly, and the outer diameter of the petal expansion cone is reduced, thereby realizing the reduction of the petal expansion cone; when the spring is compressed, the distance between the rectangular holes between the upper cone core shaft and the lower cone core shaft becomes smaller, the embedded cone moves upward along the cone surface of the upper cone core shaft, the expanding cone moves with the embedded cone, the expanding cone and the embedded cone are engaged, the outer diameter of the petal expansion cone is increased, thereby realizing the expansion of the petal expansion cone. In the composite expansion cone system for the expandable screen provided by the present invention, the initial expansion cone pre-expands the expandable screen at a relatively small expansion rate, thereby reducing the initial expansion resistance and avoiding the expansion cone being stuck due to excessive initial expansion resistance. The petal expansion cone increases the expansion rate of the expandable screen on the basis of the pre-expanded expandable screen, thereby making the expandable screen fit the well wall more closely and achieving the expected expansion rate. Furthermore, since the expansion resistance at the petal expansion cone is also the largest, the risk of the expansion cone being stuck is the greatest. When the expansion cone is stuck, the expansion cone system is lifted up, the outer diameter of the petal expansion cone is reduced, and the expansion system can be lowered again for further expansion, thereby reducing the risk of the expansion cone being stuck during construction. The diameter-guaranteed expansion cone is used to expand the pipe body again, reducing the metal rebound and making the expansion rate of the pipe column reach the design requirement as much as possible, in order to solve the problems existing in the prior art such as insufficient expansion rate of the expansion screen due to the small outer diameter of the expansion cone, failure to lower the expansion cone to the specified position due to the large outer diameter of the expansion cone, and increased risk of the expansion cone getting stuck due to the greater expansion resistance caused by the increased expansion rate even if the expansion cone with a larger outer diameter is successfully lowered to the specified position. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0043] Figure 1 A schematic structural diagram of a composite expansion cone system for an expandable screen provided in an embodiment of the present invention;

[0044] Figure 2 It is a structural schematic diagram of a composite expansion cone part in a composite expansion cone system for an expandable screen pipe, in a state where the composite expansion cone part is in a state of shrinking diameter, that is, a state where the composite expansion cone system is not working;

[0045] Figure 3 It is the mating state of the embedding cone and the expanding cone when the split expanding cone of the composite expanding cone part expands the diameter.

[0046] Figure 4 It is a structural schematic diagram of how the embedding cone and the expanding cone in the split expanding cone of the composite expanding cone part cooperate in the assembled situation.

[0047] Figure 5 It is a structural schematic diagram of the mating state of the embedding cone and the expanding cone of the composite expanding cone part.

[0048] Icon: 1 - upper sub; 2 - releasing jaw spring sleeve; 3 - releasing shear pin; 4 - releasing limit sleeve; 5 - releasing center tube; 6 - diameter - maintaining expanding cone; 7 - diameter - maintaining expanding cone connecting sleeve; 8 - spring seat; 9 - spring; 10 - connecting sleeve; 11 - upper cone core shaft; 12 - limit compression cap; 13 - upper cone sleeve; 14 - lower cone core shaft; 15 - limit pin; 16 - snap ring; 17 - embedding cone; 18 - expanding cone; 19 - lower cone sleeve; 20 - sealing sleeve; 21 - starting expanding cone; 22 - guide head; 23 - first cleaning hole; 24 - second cleaning hole; 25 - third cleaning hole. Specific embodiments

[0049] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated herein can be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0051] The following will describe in detail some embodiments of the present invention with reference to the accompanying drawings. Without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0052] The present invention provides a composite expansion cone system for an expandable screen pipe, comprising: a releasing central pipe 5, a diameter-preserving expansion cone 6, a diameter-preserving expansion cone connecting sleeve 7, a spring 9, a connecting sleeve 10, an upper cone mandrel 11, a limiting compression cap 12, an upper cone sleeve 13, a lower cone mandrel 14, a split expansion cone, a lower cone sleeve 19 and a starting expansion cone 21; wherein, the split expansion cone comprises an embedding cone 17 and an expanding cone 18; the diameter-preserving expansion cone 6 is assembled outside the releasing central pipe 5; the diameter-preserving expansion cone connecting sleeve 7 is connected to the releasing central pipe 5, and the diameter-preserving expansion cone 6 is connected to the diameter-preserving expansion cone connecting sleeve 7; the connecting sleeve 10 is connected to the lower end of the releasing central pipe 5, and the spring 9 is assembled in the lower end hole of the releasing central pipe 5; the upper cone mandrel 11 is connected to the inside of the lower end of the connecting sleeve 10, and the upper cone sleeve 13 is connected to the outside of the lower end of the connecting sleeve 10; the lower part of the limiting compression cap 12 and the spring 9 are assembled in the end hole of the upper cone mandrel 11, and the limiting compression cap 12 is connected below the spring 9; the embedding cone 17 is assembled between the upper cone mandrel 11 and the upper cone sleeve 13, and the embedding cone 17 is connected through the rectangular hole at the lower end of the upper cone mandrel 11; the lower cone mandrel 14 is connected to the threaded hole at the lower end of the limiting compression cap 12 and is assembled in the lower end hole of the upper cone mandrel 11, and the limiting compression cap 12 can slide along the axis direction of the lower end hole of the upper cone mandrel 11; the expanding cone 18 is assembled in the rectangular hole at the lower end of the lower cone mandrel 14; the lower cone sleeve 19 is connected to the lower end of the lower cone mandrel 14; the starting expansion cone 21 is assembled outside the lower cone sleeve 19; when the split expansion cone is in the reduced diameter state, the distance between the rectangular holes of the upper cone mandrel 11 becomes larger, and the contact surface between the embedding cone 17 and the expanding cone 18 decreases; when the split expansion cone is in the expanded diameter state, the distance between the rectangular holes of the upper cone mandrel 11 becomes smaller, and the contact surface between the embedding cone 17 and the expanding cone 18 increases, and the embedding cone 17 and the expanding cone 18 are engaged.

[0053] The composite expansion cone system for an expandable screen pipe provided by the present invention is in a reduced-diameter state for the entire split expansion cone when the lower cone sleeve 19 is not stressed. For the insert cone 17 and the expansion cone 18, respectively, due to the increase in the rectangular hole spacing between the upper cone mandrel 11 and the lower cone mandrel 14, and the upper cone sleeve 13 and the lower cone sleeve 19 restricting the circumferential outward displacement, the contact surface between the insert cone 17 and the expansion cone 18 decreases. The insert cone 17 moves downward along the cone surface of the upper cone mandrel 11, and the expansion cone 18 moves toward the axis accordingly, reducing the outer diameter of the split expansion cone and achieving the reduced diameter of the split expansion cone. When the spring 9 is compressed, the rectangular hole spacing between the upper cone mandrel 11 and the lower cone mandrel 14 becomes smaller. The insert cone 17 moves upward along the cone surface of the upper cone mandrel 11, and the expansion cone 18 moves with the insert cone 17. The expansion cone 18 engages with the insert cone 17, increasing the outer diameter of the split expansion cone and achieving the expansion of the split expansion cone. In the composite expansion cone system for an expandable screen pipe provided by the present invention, the starting expansion cone 21 pre-expands the expandable screen pipe at a relatively small expansion rate, reducing the initial expansion resistance and avoiding jamming the expansion cone due to excessive initial expansion resistance. The split expansion cone increases the expansion rate of the expandable screen pipe on the basis of the pre-expanded expandable screen pipe, making the expandable screen pipe fit the wellbore more closely and achieving the expected expansion rate. Moreover, since the expansion resistance at the split expansion cone is also the largest and the risk of jamming the expansion cone is the greatest, when the expansion cone is jammed, the expansion cone system is lifted, the outer diameter of the split expansion cone decreases, and the expansion system can be lowered again for re-expansion, reducing the risk of jamming the expansion cone during construction. The diameter-preserving expansion cone 6 is used to re-expand the pipe body for solid pipes, especially expandable screen pipes, because the inner diameter of the pipe string after expansion will decrease due to the metal springback and cannot reach the expansion rate at the design time, reducing the metal springback and making the expansion rate of the pipe string reach the design requirements as much as possible, solving the problems in the prior art, such as insufficient expansion rate of the expandable screen pipe due to a relatively small outer diameter of the expansion cone, the expansion cone may not be able to be lowered to the designated position due to a relatively large outer diameter of the expansion cone, and even if the expansion cone with a larger outer diameter is successfully lowered to the designated position, but due to the increase in the expansion rate, a greater expansion resistance will be brought, resulting in an increased risk of jamming the expansion cone.

[0054] The following will combine Figures 1 - 5 to detail the structure and shape of the composite expansion cone system for an expandable screen pipe provided in this embodiment.

[0055] The composite expansion cone system for an expandable screen pipe provided in this embodiment is a retractable combined anti-jamming variable-diameter expansion cone for an expandable screen pipe, including a composite expansion cone part, an emergency release part, a pipe wall cleaning part, a split expansion cone reduced diameter and reset part, and connecting parts between each part. The parts of the system are connected by threads, shear pins or profiles from bottom to top. The system is located at the lowermost end of the entire expansion tool and is connected to the upper connecting rod through the thread of the upper joint 1.

[0056] It should be noted that due to the long pipeline, the pipeline is drawn in two parts in Figure 1in the left and right figures. Therefore, in the actual product, Figure 1 the left and right figures are connected together; similarly, in the actual product, Figure 2 the left and right figures are connected together.

[0057] The composite expansion cone system for an expandable screen pipe provided in this embodiment mainly consists of an upper sub 1, a releasing pawl spring sleeve 2, a releasing shear pin 3, a releasing limit sleeve 4, a releasing central tube 5, a diameter retaining expansion cone 6, a diameter retaining expansion cone connecting sleeve 7, a spring seat 8, a spring 9, a connecting sleeve 10, an upper cone mandrel 11, a limit cap 12, an upper cone sleeve 13, a lower cone mandrel 14, a limit pin 15, a snap ring 16, an inserting cone 17, an expanding cone 18, a lower cone sleeve 19, a sealing sleeve 20, a starting expansion cone 21, a guide head 22, a first cleaning hole 23, a second cleaning hole 24, and a third cleaning hole 25.

[0058] Among them, the upper end of the upper sub 1 is connected to the connecting rod through drill pipe threads, the upper sub 1 is connected to the releasing pawl spring sleeve 2 through lower end threads, the releasing shear pin 3 is connected to the releasing limit sleeve 4 through its threaded hole, and the releasing pawl spring sleeve 2 and the releasing limit sleeve 4 are matched with the releasing central tube 5 through spatial limitation.

[0059] Among them, the releasing central tube 5 is connected to the connecting sleeve 10 through lower end threads, the spring seat 8 and the spring 9 are assembled in the lower end hole of the releasing central tube 5, so that the spring 9 can only move axially along the inner wall of the lower end hole of the releasing central tube 5; the diameter retaining expansion cone 6 is assembled on the upper cylindrical surface of the releasing central tube 5, and the diameter retaining expansion cone 6 is connected up and down with the diameter retaining expansion cone connecting sleeve 7 through threads; the diameter retaining expansion cone connecting sleeve 7 is threadedly connected to the upper and lower diameter retaining expansion cones 6 and is assembled on the upper cylindrical surface of the releasing central tube 5.

[0060] Among them, the connecting sleeve 10 is connected to the upper cone mandrel 11 through lower end internal threads and to the upper cone sleeve 13 through lower end external threads. The limit cap 12 and the spring 9 are assembled in the upper end hole of the upper cone mandrel 11, so that the spring 9 is limited between the limit cap 12 and the spring seat 8 and can only move axially between the releasing central tube 5 and the upper cone mandrel 11. The inserting cone 17 is assembled between the upper cone mandrel 11 and the upper cone sleeve 13. The inserting cone 17 is installed through the lower end rectangular hole of the upper cone mandrel 11 and is in conical surface fit. The limit pin 15 is assembled and connected to the lower cone mandrel 14 through the lower end threaded hole of the upper cone mandrel 11; the snap ring 16 is assembled through the U-shaped groove on the inserting cone 17. Specifically, the inserting cone 17 is limited by the snap ring 16 and is installed with the lower end rectangular hole of the upper cone mandrel 11 through the snap ring 16 to ensure the circumferential even distribution of the inserting cone 17. The inserting cone 17 is in fit with the expanding cone 18 through the cut surface (refer to Figures 3 - 5) The limiting compression cap 12 is assembled in the lower end hole of the upper cone mandrel 11 after being fitted with the lower cone mandrel 14 through the lower end threaded hole, enabling it to slide up and down only along the lower end hole of the upper cone mandrel 11. The upper end of the lower cone mandrel 14 and the limit pin 15 are in surface fit, allowing the lower cone mandrel 14 to move axially only along the upper end groove thereof. The diameter-expanding cone 18 is assembled in the lower end rectangular hole of the lower cone mandrel 14, and the limiting and assembly of the diameter-expanding cone 18 are completed through the space between the embedded cone 17, the snap ring 16, and the lower cone sleeve 19 and the lower cone mandrel 14. The U-shaped groove on the diameter-expanding cone 18 is fitted with the snap ring 16, and the lower cone sleeve 19 is assembled on the lower end external thread of the lower cone mandrel 14. The sealing sleeve 20 is assembled through the lower end cylindrical hole of the lower cone mandrel 14, and the sealing sleeve 20 is fitted with it through the upper end hole end face of the lower cone sleeve 19. The starting expansion cone 21 is assembled on the outer cylindrical surface of the lower cone sleeve 19, and the guide head 22 is assembled through the lower end external thread of the lower cone sleeve 19. Four diversion holes are machined on the guide head 22, enabling the fluid inside the composite expansion cone system to be flushed towards the inner wall of the pipe string to be expanded during the lowering construction process, playing a role in cleaning the inner wall of the pipe string and reducing the expansion resistance.

[0061] The composite expansion cone part includes the starting expansion cone 21, the split expansion cone (embedded cone 17, diameter-expanding cone 18), the diameter-preserving expansion cone 6, and the diameter-preserving expansion cone connecting sleeve 7. The starting expansion cone 21 pre-expands the expansion screen pipe at a relatively small expansion rate, reducing the initial expansion resistance and avoiding jamming the expansion cone due to excessive initial expansion resistance. The split expansion cone increases the expansion rate of the expansion screen pipe on the basis of completing the pre-expansion, making the expansion screen pipe fit the wellbore more closely and achieving the expected expansion rate; and since the expansion resistance at the split expansion cone is also the largest and the risk of jamming the expansion cone is the greatest, when the expansion cone is jammed, the expansion cone system is lifted, the outer diameter of the split expansion cone decreases, and the expansion system can be lowered again for expansion, reducing the risk of jamming the expansion cone during the construction process. The diameter-preserving expansion cone 6 is used to re-expand the pipe body for solid pipes, especially expansion screen pipes, because the inner diameter of the pipe string after expansion will decrease due to the metal springback and cannot reach the expansion rate at the design time, reducing the metal springback and making the expansion rate of the pipe string reach the design requirements as much as possible.

[0062] The diameter reduction and reset part of the split expansion cone includes the spring 9, the upper cone mandrel 11, the upper cone sleeve 13, the lower cone mandrel 14, the lower cone sleeve 19, and the sealing sleeve 20. When the lower cone sleeve 19 is not stressed, the entire diameter reduction and reset part of the split expansion cone is under the downward elastic force of the spring 9 and is in the lower limit position (taking Figure 1Taking the up and down directions as an example, in the composite expansion cone part, the embedded cone 17 and the diameter-expanding cone 18 respectively have the distance between the rectangular holes between the upper cone mandrel 11 and the lower cone mandrel 14 increased. The upper cone sleeve 13 and the lower cone sleeve 19 restrict the circumferential outward displacement, resulting in a decrease in the contact area between the embedded cone 17 and the diameter-expanding cone 18. The embedded cone 17 moves downward along the conical surface of the upper cone mandrel 11, and the diameter-expanding cone 18 moves towards the axis accordingly. The outer diameter of the split expansion cone in the composite expansion cone part decreases, realizing the necking of the split expansion cone. When the seal sleeve 20 is stressed, the force is transmitted to compress the spring 9, and the distance between the rectangular holes between the upper cone mandrel 11 and the lower cone mandrel 14 becomes smaller. The embedded cone 17 moves upward along the conical surface of the upper cone mandrel 11, and the diameter-expanding cone 18 moves with the embedded cone 17. The outer diameter of the split expansion cone in the composite expansion cone part increases, realizing the expansion of the split expansion cone.

[0063] The pipe wall cleaning part includes a guide head 22 and a lower cone mandrel 14. There are diversion ports on the guide head 22 and the lower cone mandrel 14, which are used to flush the fluid in the pipe string towards the pipe wall in the area to be expanded of the starting expansion cone 21 and the expanded area of the diameter-expanding cone 18 respectively, playing a role in cleaning the pipe wall and reducing the friction during expansion. Specifically, there are a first cleaning hole 23, a second cleaning hole 24, and a third cleaning hole 25 on the guide head 22 and the lower cone mandrel 14. During the construction process, the first cleaning hole 23 and the second cleaning hole 24 flush the fluid in the pipe string towards the pipe wall in the area to be expanded in front of the starting expansion cone 21; the third cleaning hole 25 flushes the fluid in the pipe string towards the pipe wall in the outer expanded area of the split expansion cone. During the construction process, the fluid forms a cycle through the internal flow channels of the composite expansion cone system and the first cleaning hole 23, the second cleaning hole 24, and the third cleaning hole 25, realizing the pipe expansion while pre-flushing the area to be expanded and flushing the expanded area, playing a role in cleaning the pipe wall, reducing the friction during expansion, and improving the success rate and safety of expansion.

[0064] The emergency releasing part includes an upper joint 1, a releasing claw spring sleeve 2, a releasing shear pin 3, a releasing limit sleeve 4, and a releasing center tube 5. When the phenomenon of the expansion cone getting stuck occurs during the expansion process, a ball is dropped from the wellhead. The ball follows the fluid through the internal pipeline of the composite expansion cone system and gets stuck on the upper conical surface of the releasing limit sleeve 4. When continuous pressure is applied from the upper part and the pressure reaches the peak value, the releasing shear pin 3 is cut short. The releasing limit sleeve 4 moves downward along the releasing center tube 5, and the upper joint 1 and the releasing claw spring sleeve 2 are disconnected from the composite expansion cone system. The upper joint 1 and the releasing claw spring sleeve 2 can be smoothly lifted out with the upper pipe string.

[0065] Refer to Figure 1 and Figure 2, the specific working process of the composite expansion cone system for the expandable screen pipe provided in this embodiment is as follows: The composite expansion cone system is connected to the connecting rod through threads. After reaching the designated position (at the expandable screen pipe) with the pipe string, the composite expansion cone system is further lowered. As the composite expansion cone system is lowered, the fluid inside the pipe string flushes the area to be expanded through the first cleaning hole 23 and the second cleaning hole 24, cleaning the inner wall of the pipe string. When the starting expansion cone 21 contacts the expandable screen pipe during further lowering of the composite expansion cone system, the expansion resistance is transmitted to the spring 9, and the spring 9 is compressed by the force. The distance between the parts of the composite expansion cone decreases, and the inserted cone 17 moves along the upper conical surface of the lower cone mandrel 14 and finally cooperates with the profile of the diameter-expanding cone 18 to complete the diameter expansion of the split expansion cone. When the expandable screen pipe reaches the split expansion cone part after being pre-expanded by the starting expansion cone 21 and enters the diameter-expanding stage, at the same time, the fluid inside the composite expansion cone system flushes and cleans the expanded part of the variable-diameter cone through the third cleaning hole 25. Continuing to lower the composite expansion cone system to reach the sizing expansion cone part and enter the sizing part, if the expansion cone is not stuck during the continuous lowering of the composite expansion cone system, the expansion is successfully completed. If the expansion cone is stuck during the expansion process, the pipe string is lifted to separate the inserted cone 17 from the diameter-expanding cone 18, and the split expansion cone contracts in diameter, then the pipe string can be smoothly lifted, and lowering it again can expand the pipe string again. If the expansion cone is stuck and cannot be released, a ball can be dropped to seal the release limit sleeve 4, and pressure is continuously applied to the upper end. When the pressure exceeds the peak value, the release shear pin 3 is cut short, and the release limit sleeve 4 moves downward along the release center pipe 5. The upper joint 1 and the release claw spring sleeve 2 are disconnected from the composite expansion cone system, and the upper joint 1 and the release claw spring sleeve 2 can be smoothly lifted and removed together with the upper part of the pipe string.

[0066] Compared with the prior art, the composite expansion cone system for an expandable screen pipe according to the present invention has the following advantages:

[0067] (1) The composite expansion cone part maximizes the expansion rate of the expandable pipe string as much as possible, reduces the risk of the expansion cone getting stuck, and reduces the springback of the pipe string after expansion to ensure that the designed expansion rate is achieved;

[0068] (2) The variable-diameter cone adopts a split structure, which can be lifted out and expanded again when the expansion cone is stuck, and to a certain extent reduces the limitation of the inner diameter of the hanger on the outer diameter of the expansion cone to achieve a greater expansion rate;

[0069] (3) There is a cleaning part, which can clean and expand the pre-expansion and expansion parts at the same time during the expansion process, further improving the expansion success rate and having higher safety;

[0070] (4) The emergency release part can separate the composite expansion cone system when the expansion cone gets stuck, and successfully remove the pipe string to avoid more complex situations.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite expansion cone system for an expandable screen pipe, characterized in that, it includes: a releasing central pipe (5), a diameter-preserving expansion cone (6), a diameter-preserving expansion cone connecting sleeve (7), a spring (9), a connecting sleeve (10), an upper cone mandrel (11), a limiting cap (12), an upper cone sleeve (13), a lower cone mandrel (14), a split expansion cone, a lower cone sleeve (19) and a starting expansion cone (21); wherein, the split expansion cone includes an embedding cone (17) and an expanding cone (18); the diameter-preserving expansion cone (6) is assembled outside the releasing central pipe (5); the diameter-preserving expansion cone connecting sleeve (7) is connected to the releasing central pipe (5), and the diameter-preserving expansion cone (6) is connected to the diameter-preserving expansion cone connecting sleeve (7); the connecting sleeve (10) is connected to the lower end of the releasing central pipe (5), and the spring (9) is assembled in the lower end hole of the releasing central pipe (5); the upper cone mandrel (11) is connected to the inside of the lower end of the connecting sleeve (10), the upper cone sleeve (13) is connected to the outside of the lower end of the connecting sleeve (10); the lower part of the limiting cap (12) and the spring (9) are assembled in the end hole of the upper cone mandrel (11), and the limiting cap (12) is connected below the spring (9); the embedding cone (17) is assembled between the upper cone mandrel (11) and the upper cone sleeve (13), and the embedding cone (17) is connected through the rectangular hole at the lower end of the upper cone mandrel (11); the lower cone mandrel (14) is connected to the threaded hole at the lower end of the limiting cap (12) and is assembled in the lower end hole of the upper cone mandrel (11), and the limiting cap (12) can slide along the axis direction of the lower end hole of the upper cone mandrel (11); the expanding cone (18) is assembled in the rectangular hole at the lower end of the lower cone mandrel (14); the lower cone sleeve (19) is connected to the lower end of the lower cone mandrel (14); the starting expansion cone (21) is assembled outside the lower cone sleeve (19); when the split expansion cone is in the reduced diameter state, the distance between the rectangular holes between the upper cone mandrel (11) and the lower cone mandrel (14) becomes larger, and the contact surface between the embedding cone (17) and the expanding cone (18) decreases; when the split expansion cone is in the expanded diameter state, the distance between the rectangular holes between the upper cone mandrel (11) and the lower cone mandrel (14) becomes smaller, the contact surface between the embedding cone (17) and the expanding cone (18) increases, and the embedding cone (17) and the expanding cone (18) are engaged.

2. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further includes a spring seat (8); the spring seat (8) is assembled in the lower end hole of the releasing central pipe (5); the spring seat (8) is connected above the spring (9).

3. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further includes a limiting nail (15); the limiting nail (15) passes through the threaded hole at the lower end of the upper cone mandrel (11) and is connected to the lower cone mandrel (14).

4. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further comprises a snap ring (16); the U-shaped groove on the embedding cone (17) is fitted with the snap ring (16); the U-shaped groove on the diameter-expanding cone (18) is fitted with the snap ring (16).

5. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further comprises a sealing sleeve (20); the sealing sleeve (20) is connected to the inside of the lower end of the lower cone mandrel (14).

6. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further comprises an upper joint (1), a release pawl spring sleeve (2), a release shear pin (3) and a release limit sleeve (4); the upper joint (1) is connected to the release pawl spring sleeve (2) through the thread at the lower end; the release shear pin (3) is connected to the release limit sleeve (4) through the upper threaded hole passing through the upper joint (1).

7. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further comprises a guide head (22); the guide head (22) is connected to the lower end of the lower cone sleeve (19).

8. The composite expansion cone system for an expandable screen pipe according to claim 7, characterized in that, it further comprises a first cleaning hole (23); the first cleaning hole (23) is provided on the guide head (22).

9. The composite expansion cone system for an expandable screen pipe according to claim 7, characterized in that, it further comprises a second cleaning hole (24); the second cleaning hole (24) is also provided on the guide head (22).

10. The composite expansion cone system for an expandable screen pipe according to claim 1, characterized in that, it further comprises a third cleaning hole (25); the third cleaning hole (25) is provided on the lower cone mandrel (14).

Images