Entry guiding and sealing device for multilateral well

Abstract

The invention belongs to the technical field of downhole tools, and particularly relates to a multilateral well entry guiding and sealing device. The multilateral well entry guiding and sealing device comprises a body; the elbow is arranged at the lower end of the body; the sealing assembly is arranged on the outer side of the elbow; the guide sleeve is arranged outside the body, and the guide sleeve is configured to be capable of being matched with a window tool to complete orientation; in a first state, the guide sleeve is fixedly connected with the body; and in the second state, the guide sleeve axially moves relative to the body. The high-pressure tie-back sealing device can be matched with a multilateral well window tool, is guided into a multilateral well hole, and realizes high-pressure tie-back sealing with a multilateral well hole well completion pipe column.

Description

Technical Field

[0001] The present invention belongs to the technical field of downhole tools, and in particular relates to a guide sealing device for entering a branch well. Background Art

[0002] Branch well technology is a key means of reducing oil and gas well development costs and improving recovery. By drilling multiple branches within a single main wellbore, this technology maximizes the drainage area and increases single-well production. It also fully utilizes the main wellbore, reduces wellsite footprint, lowers surface construction costs, and reduces overall development costs, thereby improving the overall economic benefits of oil and gas well development.

[0003] Different from conventional side drilling and horizontal well technologies, the technical difficulty of branch wells lies in the more complex completion operations in the later stage. The branch well window tool is the technical key to branch well completion. The window tool is mainly installed at the interface between the main wellbore and the branch wellbore. After installation, it can provide mechanical support at the branch well window and create conditions for the later re-entry of each wellbore.

[0004] With the application of branch well technology in unconventional oil and gas reservoirs, branch well staged fracturing technology has become a future technology development trend. Among them, how to realize branch wellbore staged fracturing has become a technical key. The conventional practice is to install the window tool, lower the branch wellbore guide to provide the branch wellbore re-entry capability, and then lower the tie-back tool through the branch wellbore guide to enter the branch wellbore and the branch wellbore string to achieve tie-back sealing, establish an independent branch wellbore fracturing channel, and finally perform branch wellbore staged fracturing operations. The problem with this method is that a dedicated branch wellbore guide needs to be lowered for branch wellbore introduction, which is relatively cumbersome and the guide needs to be salvaged again later. Secondly, due to the inner diameter limitation of the guide, the inner diameter of the tie-back device lowered later cannot achieve full bore, which limits the inner diameter of the fracturing string and the size of the fracturing tool, and cannot achieve large-scale full-bore fracturing operations. Summary of the Invention

[0005] In response to the technical problems mentioned above, the present invention aims to propose a branch well entry guide sealing device, which can cooperate with the branch well window tool, self-rotate into the branch wellbore, and achieve high-pressure back-connection sealing with the branch wellbore completion string.

[0006] According to the present invention, a branch well entry guide sealing device is provided, comprising:

[0007] ontology;

[0008] An elbow is provided at the lower end of the body;

[0009] A sealing assembly disposed on the outside of the elbow;

[0010] A guide sleeve is provided outside the body, and the guide sleeve is configured to be adapted to the window tool to complete orientation;

[0011] In the first state, the guide sleeve is fixedly connected to the body;

[0012] In the second state, the guide sleeve moves axially relative to the body.

[0013] In a specific embodiment, at least one limiting groove is provided on the outer wall of the main body, and a first through hole is provided on the side wall of the guide sleeve. In the first state, limiting blocks are provided in the limiting groove and the first through hole, so that the guide sleeve is fixedly connected to the main body; in the second state, the limiting block is disengaged from the limiting groove or the first through hole, so that the guide sleeve can move axially relative to the main body.

[0014] In a specific embodiment, a locking sleeve is provided on the outside of the guide sleeve, and a second through hole is provided on the side wall of the locking sleeve. In the first state, the inner and outer ends of the limit block respectively abut the limit groove and the inner wall of the locking sleeve; in the second state, the locking sleeve moves to the second through hole and coincides with the limit block, so that the limit block can be separated from the limit groove.

[0015] In a specific embodiment, a positioning key is provided at the lower end of the locking sleeve, and an axially penetrating key slot is provided on the guide sleeve. The positioning key is axially penetrated in the key slot. When the positioning key is axially abutted against the window tool, an axial spacing exists between the guide sleeve and the window tool, so that the locking sleeve can move to where the second through hole coincides with the limit block.

[0016] In a specific embodiment, the locking sleeve is connected to the guide sleeve via a pin.

[0017] In a specific embodiment, the lower end portion of the guide sleeve is provided with an inclined guide surface.

[0018] In a specific embodiment, a guide is provided at the lowermost end of the guide surface. The guide can be adapted to the window tool and self-rotate to guide the completion string into the branch wellbore.

[0019] In a specific embodiment, the sealing assembly includes a plurality of sealing rings, and a plurality of annular sealing grooves are axially spaced apart on the outer wall of the elbow. The sealing ring is arranged in the sealing groove by vulcanization, and a first protrusion extending into the sealing ring is provided on the outer side of the sealing groove, and a second protrusion extending into the sealing ring is provided in the middle of the sealing groove, and chamfers are provided on the edges of both ends of the sealing ring.

[0020] In a specific embodiment, a first locking ring is provided between the guide sleeve and the body.

[0021] In a specific embodiment, a second locking ring is provided between the guide sleeve and the locking sleeve.

[0022] Compared with the prior art, the advantages of this application are as follows:

[0023] The invention comprises a main body, a guide sleeve is arranged on the outside of the main body, and an elbow is arranged at the lower end of the main body. It can be self-rotating and directional introduced into the branch wellbore without the need for a special branch wellbore guide.

[0024] The elbow of the present invention is provided with a seal by vulcanization, which can realize high-pressure back-connection sealing with the branch wellbore completion string; a first protrusion extending into the sealing ring is provided on the outer side of the sealing groove, and a second protrusion extending into the sealing ring is provided in the middle of the sealing groove. Chamfers are provided on the edges of both ends of the sealing ring. The first protrusion and the second protrusion are provided in the sealing ring groove, which increases the reliability of the combination of the vulcanized sealing ring and the body. Chamfers are provided at both ends of the sealing ring, which facilitates the guide device to enter the well and move in the branch well completion string, thereby improving the reliability of the hole.

[0025] Since a branch wellbore guide is not required, and the seal is arranged on the outer wall of the main body by designing a special sealing ring groove and being integrally vulcanized, the interior of the main body of the present invention can be set to a large diameter, allowing soluble bridge plugs and the like to pass through smoothly, meeting the requirements of large-volume and full-diameter staged fracturing operations in branch wellbores, further simplifying the construction process and improving the transformation effect of unconventional reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be described below with reference to the accompanying drawings.

[0027] Figure 1 This is an overall structural diagram of the branch well entry guide sealing device provided according to the present invention.

[0028] Figure 2 The figure is a three-dimensional structural diagram of the guide sleeve provided according to the present invention.

[0029] Figure 3 3D structural diagram of the locking sleeve provided according to the present invention.

[0030] Figure 4 It is a partial assembly diagram of the locking sleeve and the guide sleeve provided according to the present invention.

[0031] Figure 5 Schematic diagram of the structure of the elbow provided according to the present invention.

[0032] Figure 6 This is a partially enlarged view of the sealing assembly provided according to the present invention.

[0033] Figure 7 This is a schematic diagram of the first state of the branch well entering the guide sealing device.

[0034] Figure 8 This is a schematic diagram of the second state of the branch well entering the guide sealing device.

[0035] In the picture:

[0036] 1. Upper joint;

[0037] 2. Ontology;

[0038] 3. Locking sleeve; 31. First observation hole; 32. Positioning key; 33. Second through hole; 34. Pin; 35. Dovetail groove;

[0039] 4. Guide sleeve; 41. First through hole; 42. First limiting groove; 43. Keyway; 44. Guide surface; 45. Guide member; 46. Small diameter portion; 47. Large diameter portion; 48. Third observation hole; 49. Limiting groove; 40. Limiting block;

[0040] 5. Elbow;

[0041] 6. Sealing assembly; 61. First protrusion; 621. Sealing groove; 622. Sealing ring; 623. Second protrusion; 64. Beveled surface;

[0042] 7. Window tools;

[0043] 81. First locking ring; 82. Second locking ring;

[0044] 100. The branch well enters the guide sealing device.

[0045] In this application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn to scale. DETAILED DESCRIPTION

[0046] The present invention will be described below with reference to the accompanying drawings.

[0047] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1 They are not intended to define the absolute positions of the components involved, but may vary depending on the specific situation.

[0048] The directional terms or qualifiers used in this application include "axial" and "radial" directions perpendicular to the central axis of the branch well entering the guide seal device 100.

[0049] Figure 1 The structure of the branch well entry guide sealing device 100 according to the present invention is shown. Figure 1 As shown, the branch well entry guide sealing device 100 includes a body 2, a guide sleeve 4, an elbow 5 and a sealing assembly 6.

[0050] In this embodiment, the body 2 is configured as a circular tube, and the guide sleeve 4 is disposed outside the body 2. In the first state, the guide sleeve 4 cannot move relative to the body 2, and the guide sleeve 4 and the body 2 are relatively fixedly connected. In the second state, the guide sleeve 4 can move axially relative to the body 2. The first state refers to the state before the guide sleeve 4 is fully adapted to the window tool 7. Figure 7 The second state refers to the state after the guide sleeve 4 and the window tool 7 are fully adapted, as shown in FIG. Figure 8 shown.

[0051] The elbow 5 is fixedly arranged at the lower end of the body 2 , and at least one sealing component 6 is arranged on the outer wall of the elbow 5 .

[0052] In this embodiment, the elbow 5 is configured as a circular tube, and the diameter of the body 2 is the same as that of the elbow 5. Figure 1 As shown, the elbow 5 is fixedly connected to the lower end of the body 2, and there is an angle between the central axis of the elbow 5 and the central axis of the body 2, and the central axis of the elbow 5 intersects the central axis of the body 2. A small angle bend design is adopted between the elbow 5 and the body 2 to facilitate guidance into the branch wellbore after self-rotation orientation.

[0053] In a preferred embodiment, the angle between the central axis of the elbow 5 and the central axis of the body 2 is between 1° and 5°.

[0054] In a preferred embodiment, the elbow 5 and the body 2 are integrally formed.

[0055] The sealing assembly 6 is fixedly arranged on the outer wall of the elbow 5 and is used to form a seal with the completion string in the branch wellbore.

[0056] During operation, the branch well enters the guide sealing device 100 in the first state. At this time, the tilt phase angle of the elbow 5 relative to the body 2 is consistent with the guiding direction of the guide sleeve 4. The window tool 7 is a downhole tool pre-installed in the branch well. The guide sleeve 4 can adapt to the window tool 7 to achieve the guiding function. The window tool 7 is well known to those skilled in the art and will not be described in detail here. When the branch well in the first state enters the guide sealing device 100 and is lowered into the guide sleeve 4 and begins to adapt to the window tool 7, the guide sleeve 4 begins to rotate and guide under the action of the window tool 7. At this time, the main body 2 is fixedly connected relative to the guide sleeve 4, so the main body 2 also rotates with the guide sleeve 4, and the elbow 5 also rotates with the main body 2. When the guide sleeve 4 and the window tool 7 are fully adapted, the elbow 5 also rotates to the corresponding branch well, and the branch well enters the guide sealing device 100 and is converted to the second state. At this time, the guide sleeve 4 can move axially relative to the main body 2, so it continues to apply pressure to the main body 2, and the guide sleeve 4 axially abuts against the window tool 7 to stop moving. The main body 2 continues to move downward relative to the guide sleeve 4 until the sealing assembly 6 on the elbow 5 is sealed with the inner wall of the branch well.

[0057] In a specific embodiment, Figure 2 and Figure 7 As shown, at least one limiting groove 49 is provided on the outer wall of the body 2 , and a first through hole 41 is provided on the side wall of the guide sleeve 4 .

[0058] In the first state, if Figure 7 As shown, a limiting block 40 is provided in the limiting groove 49 and the first through hole 41, that is, at this time, one end of the limiting block 40 is located in the first through hole 41, and the other end is located in the limiting groove 49. Under this arrangement, the limiting block 40 can limit the movement of the guide sleeve 4 relative to the main body 2, thereby fixing the guide sleeve 4 to the main body 2.

[0059] In the second state, if Figure 8 As shown, the limit block 40 moves radially outward, thereby disengaging from the limit groove 49 . At this time, the limit block 40 can no longer limit the relative movement between the guide sleeve 4 and the body 2 , so that the guide sleeve 4 can at least move axially relative to the body 2 .

[0060] like Figure 1 and Figure 4 As shown, in a specific embodiment, a locking sleeve 3 is provided on the outer side of the guide sleeve 4 , and a second through hole 33 is provided on the side wall of the locking sleeve 3 .

[0061] like Figure 7As shown, in the first state, the radial inner and outer ends of the limit block 40 respectively abut the limit groove 49 and the inner wall of the locking sleeve 3, that is, the limit block 40 cannot move at this time, so the limit block 40 can lock the main body 2 and the guide sleeve 4 through the limit groove 49 and the first through hole 41.

[0062] like Figure 8 As shown, in the second state, the locking sleeve 3 moves to the second through hole 33 and coincides with the limit block 40, that is, at this time the second through hole 33 provides space for the limit block 40 to move radially outward, so that the limit block 40 can be disengaged from the limit groove 49, and then the body 2 can move axially relative to the guide sleeve 4.

[0063] According to the present invention, Figure 3 and Figure 4 As shown, a positioning key 32 is provided at the lower end of the locking sleeve 3. The positioning key 32 is provided as an arc-shaped part, and the curvature of the positioning key 32 is the same as that of the locking sleeve 3. An axially penetrating key groove 43 is provided on the guide sleeve 4. The positioning key 32 is axially penetrated and provided in the key groove 43. In other words, the lower end of the positioning key 32 can be directly contacted from the bottom of the guide sleeve 4. After the guide sleeve 4 and the window tool 7 are rotated and guided, and before they are fully adapted, the positioning key 32 is axially abutted against the window tool 7, but there is still a partial axial distance between the guide sleeve 4 and the window tool 7, as shown in FIG. Figure 7 As shown, the positioning key 32 is located at Figure 7 On the left side, the lowest point of the guide sleeve 4 is located Figure 7 On the right side, the highest point of window tool 7 is located at Figure 7 On the left side, the lowest point of window tool 7 is located at Figure 7 At this time, the positioning key 32 has already axially abutted against the left side of the window tool 7, while there is still some axial distance between the lowest point of the guide sleeve 4 and the right side of the window tool 7. At this time, if downward pressure is continued to be applied to the body 2, the locking sleeve 3 will receive the upward abutment force of the window tool 7 through the positioning key 32, and the body 2 will move downward relative to the locking sleeve 3 with the guide sleeve 4 through the limit block 40, eventually allowing the locking sleeve 3 to move to the second through hole 33 and coincide with the limit block 40, so that the limit block 40 can move radially outward to disengage from the limit groove 49. Figure 8 shown.

[0064] On the one hand, the positioning key 32 plays the role of converting the branch well entry guide sealing device 100 from the first state to the second state, and on the other hand, it can facilitate the transfer of the locking sleeve 3 and the guide sleeve 4. On the one hand, it can also avoid circumferential rotation when the locking sleeve 3 and the guide sleeve 4 undergo relative axial displacement, so that the second through hole 33 can accurately coincide with the limit block 40.

[0065] According to the present invention, Figure 3 Figure 4 and Figure 7 As shown, in the first state, the locking sleeve 3 is connected to the guide sleeve 4 via the pins 34, preventing the locking sleeve 3 from moving relative to the guide sleeve 4 during the well landing process. In a preferred embodiment, the plurality of pins 34 are evenly distributed along the circumferential direction.

[0066] According to the present invention, Figure 2 As shown, an inclined guide surface 44 is provided at the lower end of the guide sleeve 4 , and the guide surface 44 can be matched with the inclined surface of the window tool 7 , thereby achieving a guiding effect.

[0067] According to the present invention, a guide member 45 is provided at the lowermost end of the guide surface 44 . The guide member 45 can be matched with the window tool 7 to self-rotate and guide the elbow 5 into the branch wellbore.

[0068] In a specific embodiment, the sealing assembly 6 includes a plurality of sealing rings 622 , and a plurality of annular sealing grooves 621 are axially spaced apart on the outer wall of the elbow 5 . The sealing rings 622 are disposed in the sealing grooves 621 by vulcanization.

[0069] In a preferred embodiment, a first locking ring 81 is provided between the guide sleeve 4 and the body 2. Figure 7 As shown. During the assembly process, the guide sleeve 4 is connected to the main body 2 through the first locking ring 81, which is convenient for assembly and positioning. The first locking ring 81 is constructed to limit the relative axial movement between the guide sleeve 4 and the main body 2 within a certain force range, so that the guide sleeve 4 and the main body 2 can be quickly positioned axially during the assembly process. The first locking ring 81 is constructed as an annular structure with a notch. Under normal assembly conditions, the inner wall of the first locking ring 81 contacts the main body 2, and there is a certain gap between the outer wall of the first locking ring 81 and the guide sleeve 4. The upper and lower ends of the locking ring groove on the main body 2 for accommodating the first locking ring 81 are both set as inclined surfaces. After the first locking ring 81 exceeds the bearing range, it will expand radially under the action of the inclined surface of the locking ring groove, and eventually detach from the locking ring groove, losing the restriction on the axial movement between the guide sleeve 4 and the main body 2, so that the main body 2 in the second state can move axially relative to the guide sleeve 4.

[0070] In a preferred embodiment, a second locking ring 82 is provided between the guide sleeve 4 and the locking sleeve 3. Figure 7 shown.

[0071] In this embodiment, the second locking ring 82 is similar in structure to the first locking ring 81. The second locking ring 82 is configured as an annular elastic member with a notch, such as Figure 2 and Figure 7As shown, an annular first limiting groove 42 for setting the second locking ring 82 is provided on the outer wall of the guide sleeve 4, and an annular limiting groove is provided on the inner wall of the locking sleeve 3 at a position corresponding to the first limiting groove 42. Under this arrangement, the assembly process of the locking sleeve 3 and the guide sleeve 4 is as follows: first, use a tool to open the second locking ring 82 from the notch, thereby expanding the inner diameter of the second locking ring 82 so that the second locking ring 82 can be sleeved in the first limiting groove 42 of the guide sleeve 4. After the limiting piece is sleeved in the first limiting groove 42 of the guide sleeve 4, it returns to its initial size. Then, the locking sleeve 3 is sleeved on the guide sleeve 4 from top to bottom, and a tool is used to make the limiting piece shrink using the notch, thereby reducing the outer diameter of the second locking ring 82 so that the locking sleeve 3 can smoothly pass over the second locking ring 82. When the locking sleeve 3 moves to Figure 7 In the position shown, the first limiting groove 42 of the guide sleeve 4 and the limiting groove of the locking sleeve 3 are at the same height, thereby completing the axial positioning of the locking sleeve 3 and the guide sleeve 4. At this time, the outer wall of the second locking ring 82 contacts the inner wall of the locking sleeve 3, and there is a gap between the inner wall of the second locking ring 82 and the guide sleeve 4. The upper and lower ends of the limiting groove of the locking sleeve 3 are set as inclined surfaces. When the locking sleeve 3 moves axially relative to the guide sleeve 4, the second locking ring 82 radially contracts under the action of the inclined surfaces of the limiting groove of the locking sleeve 3, disengaging from the limiting groove of the locking sleeve 3, thereby allowing the locking sleeve 3 to move axially smoothly relative to the guide sleeve 4.

[0072] According to the present invention, in a specific embodiment, Figure 2 As shown, the guide sleeve 4 includes a coaxially fixed small diameter portion 46 and a large diameter portion 47. The small diameter portion 46 is located above the large diameter portion 47, and the outer diameter of the small diameter portion is smaller than the outer diameter of the large diameter portion.

[0073] The first limiting groove 42 and the first through hole 41 are both provided on the small diameter portion 46, and the first through hole 41 is located above the first limiting groove 42. The locking sleeve 3 is sleeved on the small diameter portion 46. When the lower end of the locking sleeve 3 abuts against the upper end of the large diameter portion 47, that is, Figure 4 and Figure 7 In the position shown, the guide sleeve 4 is axially positioned with the locking sleeve 3 via the second locking ring 82 .

[0074] The structures and functions of the first locking ring 81 and the second locking ring 82 are similar and will not be described in detail here.

[0075] According to the present invention, in a specific embodiment, the end of the guide sleeve 4 is provided with a guide surface 44. Figure 2 As shown, the guide surface 44 is located at the lower end of the large diameter portion 47. The guide surface 44 is constructed as a symmetrical spiral surface, including a highest point and a lowest point. It can be regarded as the lower end of the large diameter portion 47 being intercepted by an inclined slope to form the guide surface 44, so that it can fit with the spiral orientation mechanism on the branch well window tool to form a self-rotating orientation at the branch wellbore window.

[0076] In this embodiment, if Figure 1 As shown, the lowest point of the guide surface 44 is in the same phase as the inclination direction of the elbow 5 .

[0077] In a preferred embodiment, a guide member 45 is provided at the lowermost end of the guide surface 44. The lower end of the guide member 45 is configured as a pointed end, thereby enabling more accurate orientation.

[0078] In a specific embodiment, Figure 2 As shown, a keyway 43 for cooperating with the positioning key 32 is provided on the guide sleeve 4. The keyway 43 is provided on the large diameter portion 47 and is located at the highest point of the guide surface 44. This is equivalent to providing a notch on the sleeve wall of the guide sleeve 4 at the highest point of the guide surface 44 along the axial direction to accommodate the positioning key 32. Figure 4 As shown, after the locking sleeve 3 is sleeved on the guide sleeve 4 , the positioning key 32 of the locking sleeve 3 is axially inserted into the key groove 43 of the guide sleeve 4 , and both circumferential sides of the positioning key 32 are in contact with the key groove 43 .

[0079] In a preferred embodiment, Figure 3 As shown, a dovetail groove 35 is provided at the lower end of the positioning key 32 to match the window tool 7 .

[0080] According to the present invention, in a specific embodiment, Figure 5 and Figure 6 As shown, the sealing assembly 6 includes multiple sealing rings 622. A plurality of annular sealing grooves 621 for mounting the sealing rings 622 are provided axially spaced apart on the outer wall of the elbow 5. The sealing rings 622 are made of rubber and are vulcanized and disposed in the sealing grooves 621 to ensure a large diameter of the body 2 and the elbow 5.

[0081] In a preferred embodiment, a sealing ring 622 is provided in each sealing groove 621 , one axial side of the sealing ring 622 is connected to the sealing groove 621 , and a gap exists between the other axial side of the sealing ring 622 and the sealing groove 621 .

[0082] In a preferred embodiment, Figure 6As shown, the upper portion of the sealing ring 622 is connected to the upper portion of the sealing groove 621, and a gap exists between the lower portion of the sealing ring 622 and the sealing groove 621. Furthermore, a first protrusion 61 extending toward the sealing ring 622 is provided on the outer side of the upper portion of the sealing groove 621 (i.e., the outer side of the end of the sealing groove 621 that contacts the sealing ring 622), and the first protrusion 61 extends into the sealing ring 622. This arrangement allows, on the one hand, the first protrusion 61 to connect with the sealing ring 622, providing a certain fixing force for the sealing ring 622, thereby further strengthening the connection between the sealing ring 622 and the sealing groove 621. Furthermore, during the well entry process, the protrusion 61 can tightly hold the sealing ring 622, preventing the sealing ring 622 from being subjected to the upward force from the well wall and causing the connection between the sealing ring 622 and the sealing groove 621 to fail, thereby further strengthening the connection between the sealing ring 622 and the sealing groove 621.

[0083] Furthermore, the outer diameter of the sealing ring 622 is larger than the outer diameters of the first protrusion 62 and the elbow 5, and chamfers are provided at the outer edges of the upper and lower ends of the sealing ring 622. In other words, the outer edges of the upper and lower ends of the sealing ring 622 are provided as inclined surfaces. The provision of chamfers improves the reliability of the via hole and further improves the reliability of the connection between the sealing ring 622 and the sealing groove 621.

[0084] Furthermore, a second protrusion 623 is provided in the middle of the sealing groove 621 . The second protrusion 623 extends to the inside of the sealing ring 622 . The second protrusion 623 can enhance the reliability of the combination between the sealing ring 622 and the sealing groove 621 .

[0085] According to the present invention, the spacing between the sealing grooves 621 can be set to be equal or unequal.

[0086] In a preferred embodiment, Figure 5 As shown, a beveled surface 64 is provided at the lower end of the elbow 5, and the beveled surface 64 is in the same phase as the beveled direction of the elbow 5 relative to the body 2. This arrangement enables the elbow 5 to enter the branch wellbore more smoothly.

[0087] In a preferred embodiment, a soluble semi-spherical guide shoe (not shown) is provided at the lower end of the elbow 5, and the soluble semi-spherical guide shoe is in the same phase as the bevel direction of the elbow 5 relative to the body 2. This arrangement enables the elbow 5 to enter the branch wellbore more smoothly.

[0088] According to the present invention, an upper joint 1 for connecting with a sleeve is provided at the upper end of the body 2. Furthermore, the upper joint 1 is configured to be rotatably connected to the body 2, that is, the body 2 can rotate circumferentially relative to the upper joint 1.

[0089] During operation, the upper end of the upper connector 1 is connected to the oil pipe or other downhole tool, which provides a downward force to the upper connector 1 and the main body 2 through the oil pipe or other downhole tool, so that the main body 2 can move downward. During the process of guiding and adapting the guide sleeve 4 and the window tool 7, the main body 2 can rotate relative to the upper connector 1. When the main body 2 moves downward relative to the guide sleeve 4 until the sealing assembly 6 of the elbow 5 seals with the completion string in the branch well, the upper connector 1 axially abuts against the locking sleeve 3.

[0090] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0091] In the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connect," "fixed," etc. should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediary; or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0092] Throughout this specification, reference to terms such as "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" means that a specific feature, structure, material, or characteristic described in conjunction with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0093] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A branch well entry guide sealing device, characterized in that: include: Ontology(2); An elbow (5) provided at the lower end of the body (2); a sealing assembly (6) arranged on the outside of the elbow (5); A guide sleeve (4) is arranged outside the body (2), and the guide sleeve (4) is configured to be adapted to a window tool to complete orientation; In the first state, the guide sleeve (4) is fixedly connected to the body (2); In the second state, the guide sleeve (4) moves axially relative to the body (2).

2. The branch well entry guide sealing device according to claim 1, characterized in that: At least one limiting groove is provided on the outer wall of the body (2), and a first through hole (41) is provided on the side wall of the guide sleeve (4). In the first state, a limiting block is provided in the limiting groove and the first through hole (41), so that the guide sleeve (4) is fixedly connected to the body (2); In the second state, the limiting block is disengaged from the limiting groove, thereby enabling the guide sleeve (4) to move axially relative to the body (2).

3. The branch well entry guide sealing device according to claim 2, characterized in that: A locking sleeve (3) is provided on the outer side of the guide sleeve (4), and a second through hole (33) is provided on the side wall of the locking sleeve (3). In the first state, the inner and outer ends of the limiting block respectively abut against the limiting groove and the inner wall of the locking sleeve (3); In the second state, the locking sleeve (3) moves until the second through hole (33) overlaps with the limiting block, thereby enabling the limiting block to be separated from the limiting groove.

4. The branch well entry guide sealing device according to claim 3, characterized in that: A positioning key (32) is provided at the lower end of the locking sleeve (3), and an axially penetrating key groove (43) is provided on the guide sleeve (4). The positioning key (32) is axially penetrated in the key groove (43). When the positioning key (32) is axially abutted against the window tool, an axial spacing exists between the guide sleeve (4) and the window tool, so that the locking sleeve (3) can move to the second through hole (33) to coincide with the limit block.

5. The branch well entry guide sealing device according to claim 3 or 4, characterized in that: The locking sleeve (3) is connected to the guide sleeve (4) via a pin (34).

6. The branch well entry guide sealing device according to any one of claims 1 to 4, characterized in that: The lower end of the guide sleeve (4) is provided with an inclined guide surface (44).

7. The branch well entry guide sealing device according to claim 6, characterized in that: A guide member (45) is provided at the lowermost end of the guide surface (44). The guide member (45) can be adapted to the window tool and self-rotate to guide the completion string into the branch wellbore.

8. The branch well entry guide sealing device according to any one of claims 1 to 4, characterized in that: The sealing assembly (6) includes a plurality of sealing rings (622), and a plurality of annular sealing grooves (621) are arranged at intervals along the axial direction on the outer wall of the elbow (5). The sealing ring (622) is arranged in the sealing groove (621) by vulcanization. A first protrusion (61) extending into the sealing ring (622) is arranged on the outer side of the sealing groove (621), and a second protrusion (623) extending into the sealing ring (622) is arranged in the middle of the sealing groove (621). The edges of both ends of the sealing ring (622) are chamfered.

9. The branch well entry guide sealing device according to any one of claims 1 to 4, characterized in that: A first locking ring is provided between the guide sleeve (4) and the body (2).

10. The branch well entry guide sealing device according to claim 3 or 4, characterized in that: A second locking ring is provided between the guide sleeve (4) and the locking sleeve (3).

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