Tie-back expansion type drilling liner hanger

Abstract

According to the tieback expansion type drilling liner hanger, a first tube section, a second tube section, a tieback barrel and a drilling liner are sequentially in butt joint in the axial direction; the central pipe is arranged in the expansion pipe and the tie-back cylinder in a penetrating manner, and the tail pipe rubber plug is fixed at the bottom end of the central pipe and is plugged between the bottom end of the central pipe and the opposite part of the tie-back cylinder; the expansion cone is arranged on the central pipe in a sleeving manner and is in contact with the second pipe section; the bumping seat is mounted at the end part, deviating from the tie-back cylinder, of the tail pipe; the tail pipe rubber plug is used for being matched with a drill plug rubber plug fed from the center pipe in a plugging mode so that working liquid can form a first pressure building state in the center pipe. In the first pressure building state, the tail pipe rubber plug is separated from the central pipe, and the whole formed by the tail pipe rubber plug and the drill plug rubber plug falls to the bump pressure seat and is matched with the bump pressure seat in a plugging manner, so that the working liquid forms a second pressure building state in the central pipe; and in the second pressure building state, the working liquid enters the space between the central pipe and the tie-back barrel to drive the expansion cone to move so as to expand the first pipe section.

Description

Technical Field

[0001] This invention relates to the field of suspension design technology, and more particularly to a reversible expandable tailpipe suspension. Background Technology

[0002] Tailtub completion is a common well completion method widely used in current oil and gas field production. With the deepening development of unconventional oil and gas resources, volumetric fracturing technology is being applied more extensively. The specific process of tailtub reconnection volumetric fracturing technology is as follows: After the tailtub is suspended and cemented, the drill bit is run in to clean the upper and lower cement plugs left from the cementing process to ensure unobstructed flow in the wellbore. Then, the reconnection tube is cleaned and trimmed with a milling shoe. The reconnection connector, hydraulic anchor, packer, and reconnection string are then sequentially run in. The reconnection connector is reconnected, and annular and wellbore pressure tests are performed. Finally, the Christmas tree is installed. The completion of the reconnection operation provides a safe and reliable wellbore for subsequent volumetric fracturing operations, ensuring the safety and efficiency of subsequent oil and gas production.

[0003] In the back-connection operations involved in related technologies, slip-type liner hangers are generally used for liner completion operations. While slip-type liner hangers can suspend the liner, they lack a sealing function. This can easily lead to flow of cement stone outside the liner under the high pressure of volumetric fracturing technology, resulting in annular pressure and affecting the sealing integrity and safety of the wellbore. This can adversely affect the on-site fracturing operation. Summary of the Invention

[0004] This invention discloses a reversible expandable tailpipe hanger to solve the problem that slip-type tailpipe hangers cannot complete the sealing during reconnection operations in related technologies.

[0005] To address the aforementioned technical problems, the present invention discloses the following technical solutions:

[0006] This invention discloses a reversible expandable tailpipe hanger for reconnecting a tailpipe to a sleeve. The reversible expandable tailpipe hanger includes a central tube, an expansion tube, an expansion cone, a tailpipe rubber plug, a pressure seat, a tailpipe, a reconnection cylinder, and a drill plug rubber plug.

[0007] The expansion tube includes a first pipe section, a second pipe section, and an annular sealing structure disposed on the outer peripheral wall of the first pipe section. The diameter of the first pipe section is smaller than the diameter of the second pipe section. The first pipe section, the second pipe section, the return cylinder, and the tail pipe are axially connected in sequence.

[0008] The central tube passes through the expansion tube and the return tube. The tail tube plug is fixed to the bottom end of the central tube and seals the area between the bottom end of the central tube and the return tube. The expansion cone is sleeved on the central tube and contacts the second tube section.

[0009] The pressure seat is installed at the end of the tailpipe opposite to the return cylinder; the tailpipe rubber plug is used to cooperate with the drill plug rubber plug inserted from the central tube to seal and make the working fluid form a first pressure-locked state in the central tube.

[0010] During the first pressurized state, the tailpipe plug separates from the central tube, and the entire structure formed by the tailpipe plug and the drill plug plug falls to the pressure seat and seals with the pressure seat so that the working fluid forms a second pressurized state in the central tube.

[0011] In the second pressurized state, the working fluid enters between the central tube and the return cylinder to drive the expansion cone to move and expand the first pipe section, so that the first pipe section is sealed and fixed to the sleeve through the annular sealing structure.

[0012] In one embodiment of the reversible expandable tailpipe hanger, there are multiple annular sealing structures, and the multiple annular sealing structures are axially spaced apart in the first pipe section.

[0013] In one embodiment of the reversible expandable tailpipe hanger, the expansion tube further includes a third pipe section, which is a tapered section. The small end of the third pipe section is connected to the first pipe section, and the large end of the third pipe section is connected to the second pipe section. The conical surface of the expansion cone is adapted to the shape of the pipe wall of the third pipe section.

[0014] In one embodiment of the reversible expandable tailpipe hanger, the reversible expandable tailpipe hanger further includes a connecting sleeve, the connecting sleeve being connected to the bottom end of the central tube, and the tailpipe rubber plug being fitted onto the connecting sleeve and connected to the connecting sleeve by a shearing screw.

[0015] During the first pressurized state, the working fluid in the central tube drives the tailpipe stopper to cut the shear screw, thereby separating it from the central tube.

[0016] In one embodiment of the reversible expandable tailpipe hanger, the connecting sleeve is fixed to the bottom end of the central tube by a threaded engagement.

[0017] In one embodiment of the retractable expandable tailpipe suspension, the retractable expandable tailpipe suspension further includes a floater connected to the end of the impact seat facing away from the tailpipe.

[0018] In one embodiment of the reversible expandable tailpipe hanger, the top end of the central tube is a threaded connection end.

[0019] In one embodiment of the reversible expandable tailpipe hanger, the expansion tube, the reconnection sleeve, and the tailpipe are sequentially and fixedly connected by threaded connections.

[0020] In one embodiment of the reversible expandable tailpipe hanger, the inner wall of the reversible cylinder is a smooth inner wall.

[0021] In one embodiment of the reversible expandable tailpipe suspension, the hardness of the expansion cone is greater than the hardness of the expansion tube.

[0022] The technical solutions disclosed in the embodiments of the present invention have the following technical effects:

[0023] The reversible expandable tailpipe hanger disclosed in this invention can realize the reconnection of the tailpipe. At the same time, the expansion tube can be fixedly connected to the casing by expansion, and can also achieve a sealing fit with the inner wall of the casing through the annular sealing structure. Ultimately, it can achieve the sealing function, thereby avoiding problems such as the flow of cement stone outside the tailpipe under the high pressure of volumetric fracturing technology. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the reversible expandable tailpipe hanger disclosed in an embodiment of the present invention.

[0025] The components in the diagram are labeled as follows:

[0026] 10- Tailpipe,

[0027] 20 - Central pipe, 30 - Expansion pipe, 31 - First pipe section, 32 - Second pipe section, 33 - Annular sealing structure, 34 - Third pipe section

[0028] 40-Expansion cone, 50-Tailpipe rubber plug, 60-Pressure seat, 70-Return sleeve, 80-Drill plug rubber plug, 90-Connecting sleeve, 100-Floating shoe, 110-Casing. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0030] The technical solutions disclosed in the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0031] Please refer to Figure 1 This invention discloses a reversible expandable tailpipe hanger. The disclosed reversible expandable tailpipe hanger is used to reconnect the tailpipe 10 to the sleeve 110. The reversible expandable tailpipe hanger disclosed in this invention includes a center tube 20, an expansion tube 30, an expansion cone 40, a tailpipe rubber plug 50, a pressing seat 60, a tailpipe 10, a reconnection cylinder 70, and a drill plug rubber plug 80.

[0032] The central tube 20 is the main frame of the retractable expandable keel shaft hanger. The central tube 20 is used to connect with the lowering equipment (e.g., drill pipe), thereby connecting the entire retractable expandable keel shaft hanger to the lowering equipment. Driven by the lowering equipment, the entire retractable expandable keel shaft hanger can be lowered to a preset position.

[0033] The expansion tube 30 is a tubular component that needs to be expanded and tightened onto the inner wall of the sleeve 110. The expansion tube 30 is connected to the tail tube 10. After being tightened, the expansion tube 30 achieves a fixed connection with the sleeve 110, and simultaneously, the tail tube 10 is also connected to the sleeve 110. In this embodiment of the invention, the expansion tube 30 is a stepped tubular component, comprising a first pipe section 31, a second pipe section 32, and an annular sealing structure 33 disposed on the outer peripheral wall of the first pipe section 31. The second pipe section 32 is located below the first pipe section 31. The first pipe section 31 has a smaller diameter than other parts of the expansion tube 30 (e.g., the second pipe section 32), and is the portion of the expansion tube 30 that is to be expanded and tightened onto the inner wall of the sleeve 110.

[0034] It should be noted that after the first pipe section 31 expands and its diameter increases, the annular sealing structure 33 mounted on it tightens onto the sleeve 110. The annular sealing structure 33 achieves a tight seal with the inner wall of the sleeve 110, ensuring both tightening and sealing. The expansion tube 30 is also sleeved outside the central tube 20. In this embodiment of the invention, the first pipe section 31, the second pipe section 32, the reconnection sleeve 70, and the tail pipe 10 are axially connected sequentially. The reconnection sleeve 70 connects the expansion tube 30 to the tail pipe 10. The reconnection sleeve 70 has sufficient length to ensure that the tail pipe 10 can be reconnected. The reconnection sleeve 70 then expands and tightens within the sleeve 110 through the expansion tube 30, ultimately achieving the reconnection of the tail pipe 10.

[0035] In this embodiment of the invention, the central tube 20 passes through the expansion tube 30 and the return sleeve 70. The tail tube plug 50 is fixed to the bottom end of the central tube 20, and the expansion cone 40 is sleeved on the central tube 20 and contacts the second tube segment 32. It should be noted that, in this text, the top end and the bottom end are the opposite ends of the related components, wherein the bottom end is lower than the top end and is located below the top end. The tail tube plug 50 is used to cooperate with the drill plug plug 80 to perform sealing, and is also used to cooperate with the drill plug plug 80 to form a whole to cooperate with the pressing seat 60 to achieve sealing. The tailpipe stopper 50 is fixed to the bottom end of the central tube 20 and seals the area between the bottom end of the central tube 20 and the opposite part of the return tube 70. When the tailpipe stopper 50 is connected to the bottom end of the central tube 20, the tailpipe stopper 50 can seal the area between the bottom end of the central tube 20 and the opposite part of the return tube 70, thereby preventing the working fluid (e.g., water) from entering from the area between the bottom end of the central tube 20 and the opposite part of the return tube 70, and thus preventing the working fluid from entering the space where the expansion cone 40 is located.

[0036] The expansion cone 40 is fitted onto the central tube 20 and contacts the second tube segment 32. It can slide relative to the central tube 20 and the second tube segment 32 under a large driving force. Once the working fluid enters the space occupied by the expansion cone 40, it will drive the expansion cone 40 upwards, forcibly sliding between the central tube 20 and the first tube segment 31. Due to the large diameter of the expansion cone 40, it will expand the first tube segment 31 as it moves upwards along the central tube 20. Essentially, the expansion cone 40 is positioned between the central tube 20 and the second tube segment 32, effectively connecting the second tube segment 32 and the central tube 20 under the influence of a large driving force, thereby connecting the central tube 20 and the expansion tube 30.

[0037] It should be noted that, as mentioned above, the central tube 20 is the central frame of the reversible expansion tailpipe suspension, which has greater strength and rigidity. The first tube segment 31 has less strength. When the expansion cone 40 slides upward along the central tube 20, it can expand the first tube segment 31. At the same time as the first tube segment 31 is expanded, the annular sealing structure 33 fitted on it will also be expanded and thus fixed on the inner wall of the sleeve 110. At the same time, the annular sealing structure 33 seals between the first tube segment 31 and the sleeve 110.

[0038] The pressure seat 60 is installed at the end of the tailpipe 10 away from the return sleeve 70. The tailpipe rubber plug 50 is used to seal and cooperate with the drill plug rubber plug 80 inserted from the central tube 20 so that the working fluid forms a first pressure state in the central tube 20.

[0039] During the first pressurization state, the tailpipe stopper 50 separates from the central tube 20. Specifically, during the first pressurization state, the working fluid accumulates, causing its pressure to increase, thereby driving the tailpipe stopper 50 to separate from the central tube 20. The tailpipe stopper 50 and the drill plug stopper 80 together descend to the pressure seat 60 and seal against it, thus creating a second pressurization state for the working fluid in the central tube 20. It should be noted that the pressure of the working fluid in the second pressurization state is greater than the pressure of the working fluid in the first pressurization state.

[0040] During the second pressurization state, the working fluid enters between the central tube 20 and the return tube 70 to drive the expansion cone 40 to move and expand the first tube section 31, so that the first tube section 31 is sealed and fixed to the sleeve 110 through the annular sealing structure 33.

[0041] The working process of the reversible expandable tailpipe hanger disclosed in this invention is as follows:

[0042] The central tube 20 is connected to the lowering device. Driven by the lowering device, the central tube 20 will drive the expansion tube 30, the return tube 70, the tail tube 10 and the pressure seat 60 downward through the expansion cone 40. Of course, the tail tube rubber plug 50 at the bottom of the central tube 20 will also descend. When the reconnectable expansion tail tube hanger is lowered to the predetermined position, the drill plug rubber plug 80 is inserted. The drill plug rubber plug 80 falls down along the cavity of the central tube 20 onto the tail tube rubber plug 50 and seals the tail tube rubber plug 50. As the working fluid is introduced, the working fluid will accumulate and become pressurized after entering the central tube 20 because it cannot be discharged, thus forming the first pressurized state in the central tube 20. When in the first pressurized state, the pressure of the working fluid is relatively high, which separates the tailpipe rubber plug 50 and the central tube 20. This allows the tailpipe rubber plug 50 and the drill plug rubber plug 80 to fall as a whole to the pressure seat 60, and further seal with the pressure seat 60, so that the working fluid forms a second pressurized state with higher pressure in the central tube 20.

[0043] In the second pressurized state, the tailpipe plug 50 separates from the central tube 20, thereby opening the space between the central tube 20 and the return sleeve 70. The working fluid enters between the central tube 20 and the return sleeve 70 to drive the expansion cone 40 to move and expand the first pipe section 31. The first pipe section 31 is then sealed and fixed to the sleeve 110 through the annular sealing structure 33, thus achieving the fixation and sealing between the expansion tube 30 and the sleeve 110. This allows the tailpipe 10 to be connected to the sleeve 110 through the return sleeve 70 and the expansion tube 30.

[0044] As can be seen from the above working process, the reversible expandable tailpipe hanger disclosed in the embodiments of the present invention can realize the reconnection of the tailpipe 10. At the same time, the expansion tube 30 can be fixedly connected to the sleeve 110 through expansion, and can also achieve a sealing fit with the inner wall of the sleeve 110 through the annular sealing structure 33. Ultimately, it can achieve the sealing function, thereby avoiding problems such as the flow of cement stone outside the tailpipe 10 under the high pressure of volumetric fracturing technology.

[0045] As described above, after expansion, the expansion tube 30 achieves a seal with the sleeve 110 through the annular sealing structure 33. The expansion tube 30 may contain one or more annular sealing structures 33, and this embodiment of the invention is not limited thereto. In one embodiment, there are multiple annular sealing structures 33, which can be distributed axially at intervals along the first pipe segment 31. This structure allows the expansion tube 30 to achieve a seal with the sleeve 110 through multiple annular sealing structures 33 along its axial direction after expansion, thus improving the sealing effect.

[0046] The expansion tube 30 disclosed in this embodiment of the invention may only include the first tube segment 31 and the second tube segment 32 mentioned above. The expansion cone 40, in its original position, is fitted onto the central tube 20 and contacts the second tube segment 32. During expansion, the expansion cone 40 moves upward along the central tube 20, thereby forcibly sliding from the second tube segment 32 into the first tube segment 31, ultimately expanding the first tube segment 31. To facilitate the sliding of the expansion cone 40 into the first tube segment 31, in a further optional embodiment, the expansion tube 30 disclosed in this embodiment of the invention may also include a third tube segment 34. The third tube segment 34 is a tapered segment, with its small end connected to the first tube segment 31 and its large end connected to the second tube segment 32. The tapered surface of the expansion cone 40 is adapted to the shape of the tube wall of the third tube segment 34. This structure not only allows the expansion cone 40 fitted onto the central tube 20 to better engage with the expansion tube 30 through the conical surface, but also allows the expansion cone 40 to slide into the first tube section 31 through the third tube section 34. Since the third tube section 34 is a conical section, it makes it easier for the expansion cone 40 to slide into the first tube section 31, which ultimately benefits subsequent expansion.

[0047] The reversible expandable tailpipe hanger disclosed in this embodiment of the invention may further include a connecting sleeve 90. The connecting sleeve 90 can be connected to the bottom end of the central tube 20. Specifically, the connecting sleeve 90 can be connected to the bottom end of the central tube 20 by means of a threaded connection. The tailpipe rubber plug 50 is sleeved on the connecting sleeve 90 and connected to the connecting sleeve 90 by a shearing screw.

[0048] During the first pressurization state, the working fluid in the central tube 20 drives the tail tube rubber plug 50 to cut the shear screw, thereby separating it from the central tube 20.

[0049] The retractable inflatable tailpipe suspension disclosed in this embodiment of the invention may further include a float 100, which is connected to the end of the pressure seat 60 facing away from the tailpipe 10, that is, the float 100 is connected to the bottom end of the pressure seat 60. The float 100 can play a guiding role, thereby enabling the retractable inflatable tailpipe suspension to descend more effectively.

[0050] In this embodiment of the invention, the expansion tube 30, the reconnecting sleeve 70, and the tail tube 10 can be sequentially and fixedly connected by threaded engagement. The threaded engagement method not only has the advantage of simple structure but also facilitates their assembly and disassembly. To make expansion easier, in the reconnectable expansion tail tube hanger disclosed in this embodiment of the invention, the hardness of the expansion cone 40 can be greater than that of the expansion tube 30. The greater hardness of the expansion cone 40 makes it easier to drive the expansion tube 30 to deform, thereby producing an expansion effect.

[0051] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A retractable expandable tailpipe hanger for reconnecting the tailpipe (10) to the sleeve (110), characterized in that, The reversible expandable tailpipe hanger includes a center tube (20), an expansion tube (30), an expansion cone (40), a tailpipe rubber plug (50), a pressure seat (60), a tailpipe (10), a reconnection cylinder (70), and a drill plug rubber plug (80), wherein, The expansion tube (30) includes a first pipe section (31), a second pipe section (32), and an annular sealing structure (33) disposed on the outer peripheral wall of the first pipe section (31). The diameter of the first pipe section (31) is smaller than the diameter of the second pipe section (32). The first pipe section (31), the second pipe section (32), the return cylinder (70), and the tail pipe (10) are axially connected in sequence. The central tube (20) passes through the expansion tube (30) and the return tube (70), the tail tube plug (50) is fixed on the bottom end of the central tube (20) and seals the part between the bottom end of the central tube (20) and the return tube (70); the expansion cone (40) is sleeved on the central tube (20) and contacts the second tube section (32); The pressure seat (60) is installed at the end of the tail tube (10) away from the return tube (70); the tail tube plug (50) is used to cooperate with the drill plug plug (80) inserted from the central tube (20) to seal and make the working fluid form a first pressure state in the central tube (20); In the first pressurized state, the tailpipe plug (50) separates from the central tube (20), and the tailpipe plug (50) and the drill plug plug (80) together fall to the pressure seat (60) and seal with the pressure seat (60) so that the working fluid forms a second pressurized state in the central tube (20); In the second pressurized state, the working fluid enters between the central tube (20) and the return tube (70) to drive the expansion cone (40) to move and expand the first pipe section (31), and the first pipe section (31) is sealed and fixed to the sleeve (110) through the annular sealing structure (33).

2. The reversible expandable tailpipe suspension according to claim 1, characterized in that, The annular sealing structure (33) is multiple and is distributed axially at intervals in the first pipe section (31).

3. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The expansion tube (30) also includes a third tube section (34), which is a tapered section. The small end of the third tube section (34) is connected to the first tube section (31), and the large end of the third tube section (34) is connected to the second tube section (32). The tapered surface of the expansion cone (40) is adapted to the shape of the tube wall of the third tube section (34).

4. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The reversible expandable tailpipe hanger also includes a connecting sleeve (90), which is connected to the bottom end of the central tube (20). The tailpipe rubber plug (50) is fitted onto the connecting sleeve (90) and connected to the connecting sleeve (90) by a shear screw. During the first pressurized state, the working fluid in the central tube (20) drives the tail tube plug (50) to cut the shear screw, thereby separating it from the central tube (20).

5. The reversible expandable tailpipe hanger according to claim 4, characterized in that, The connecting sleeve (90) is fixed to the bottom end of the central tube (20) by a threaded connection.

6. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The retractable expandable tailpipe suspension also includes a float shoe (100), which is connected to the end of the impact seat (60) facing away from the tailpipe (10).

7. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The top end of the central tube (20) is a threaded connection end.

8. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The expansion tube (30), the return tube (70), and the tail tube (10) are sequentially connected by threaded connections.

9. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The inner wall of the return tube (70) is a smooth inner wall.

10. The reversible expandable tailpipe hanger according to claim 1, characterized in that, The hardness of the expansion cone (40) is greater than that of the expansion tube (30).

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