A float shoe for liner cementing

Abstract

The invention relates to a float shoe for liner cementing, comprising a cylindrical housing, a guide head arranged at one end of the housing, and a connection mechanism connecting the housing and the guide head together and configured to allow one-way rotation of the guide head relative to the housing about an axis of the housing.

Description

Technical Field

[0001] This invention relates to the field of tailpipe cementing technology, and more particularly to a float shoe for tailpipe cementing. Background Technology

[0002] Tailpipe cementing is a common construction process. During the lowering of the tailpipe, obstruction is inevitable, specifically, the tailpipe float shoe becoming stuck against the wellbore. Removing this obstruction is a significant challenge in current construction processes. Typically, only high-volume flushing can effectively remove the obstruction.

[0003] In conventional casing cementing, the casing is usually rotated to release obstruction. However, in current tailpipe cementing, the tailpipe string is required to remain stationary after the ordinary tailpipe hanger is inserted into the well, which makes it impossible to release obstruction by driving the tailpipe to rotate.

[0004] In addition, casing cementing can generally be unblocked by using a rotating float shoe. However, rotating float shoes used in casing cementing cannot be directly applied to liner cementing. This is mainly because existing rotating float shoes for casing cementing can rotate bidirectionally or freely. However, for liner cementing, in order to facilitate subsequent liner release operations, the rotating float shoes used for liner cementing must not rotate bidirectionally or freely. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes a float shoe for tailpipe cementing, which can be used to deblock tailpipe strings.

[0006] The present invention proposes a float shoe for tailpipe cementing, comprising: a cylindrical housing, a guide head disposed at one end of the housing, and a connecting mechanism that connects the housing to the guide head and is configured to allow the guide head to rotate unidirectionally relative to the housing about the axis of the housing.

[0007] When the guide head contacts and encounters resistance against the well wall, it can rotate relative to the casing under the action of the well wall, thereby avoiding the contact with the well wall. In this way, it is possible to effectively remove resistance during the tailpipe lowering process.

[0008] In a preferred embodiment, a wing is constructed on the outer side of the guide head, the wing being configured to contact the wellbore wall to drive the guide head to rotate.

[0009] In a preferred embodiment, the wing has a helical profile.

[0010] In a preferred embodiment, the guide head is configured with a plurality of wing plates that are evenly distributed in the circumferential direction.

[0011] In a preferred embodiment, the connecting mechanism includes: a first engagement tooth configured on the radially outer side of the guide head; a stop block radially disposed between the guide head and the housing, with a second engagement tooth configured to engage with the first engagement tooth on the radially inner side of the stop block; and a limiting block configured to push the stop block radially inward so that the second engagement tooth of the stop block engages with the first engagement tooth of the guide head; wherein, when the guide head has a tendency to rotate in a first direction, the stop block can move radially outward relative to the guide head to separate the first engagement tooth from the second engagement tooth, allowing the guide head to rotate relative to the housing in the first direction; when the guide head has a tendency to rotate in a second direction, the limiting block keeps the first engagement tooth engaged with the second engagement tooth to prevent the guide head from rotating relative to the housing in the second direction, which is opposite to the first direction.

[0012] In a preferred embodiment, the stop block, the limiting block, the guide head, and the housing are all made of rigid material.

[0013] In a preferred embodiment, the limiting block protrudes radially inward relative to the housing and is fixedly connected to the housing. The limiting block is located on one side of the stop in the circumferential direction. The limiting block has a contact surface facing the stop. The contact surface is inclined inward in a second direction. When the guide head has a tendency to rotate in the second direction, the contact surface can act on the stop to keep the first meshing tooth and the second meshing tooth engaged.

[0014] In a preferred embodiment, the contact surface is curved, and the curvature of the contact surface gradually increases along the second direction.

[0015] In a preferred embodiment, the connecting mechanism further includes an elastic element disposed circumferentially on the other side of the stop, the elastic element being configured to push the stop so that the stop abuts against the contact surface.

[0016] In a preferred embodiment, the connecting mechanism includes multiple sets of the stops, the limiting blocks, and the elastic elements, which are evenly distributed circumferentially. In one of the multiple sets, one end of the elastic element is in contact with the stop in the same set, and the other end is in contact with the limiting block in an adjacent set.

[0017] In a preferred embodiment, the first meshing tooth and the second meshing tooth have an involute tooth shape, a circular arc tooth shape, a square tooth shape, or a pointed tooth shape. Attached Figure Description

[0018] The invention will be described in more detail below with reference to the accompanying drawings. Wherein:

[0019] Figure 1 A schematic diagram of the overall structure of a float shoe for tailpipe cementing according to a first embodiment of the present invention is shown;

[0020] Figure 2 Showing Figure 1 A schematic structure of the connection mechanism for the float shoe used in tailpipe cementing;

[0021] Figure 3 Showing Figure 1 A bottom view of the float shoe used for tailpipe cementing.

[0022] In the accompanying drawings, the same parts use the same reference numerals. The drawings are not drawn to scale. Detailed Implementation

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] This invention proposes a float shoe 100 for tailpipe cementing. For example... Figure 1 As shown, the floating shoe 100 includes a generally cylindrical housing 1, a one-way valve 3 fitted inside the housing 1, and a cement body 2 made of cement disposed between the housing 1 and the one-way valve 3. The one-way valve 3 allows fluid to flow from upstream to downstream within the housing 1 (in... Figure 1 The flow direction is from top to bottom. A sealing ring 4 is also provided between the housing 1 and the one-way valve 3, and this sealing ring is located at the lower end of the cement body 2. O-rings 5 ​​and 6 are respectively provided on the inner and outer sides of the sealing ring 4. The sealing ring 4 and O-rings 5 ​​and 6 prevent fluid from flowing through the annular gap between the housing 1 and the one-way valve 3. A plurality of first circulation holes 7 are also provided on the side wall of the housing 1. These first circulation holes 7 are located between the lower end of the housing 1 and the one-way valve 3. For example, 12 first circulation holes 7 can be provided, or more or fewer first circulation holes 7 can be provided.

[0025] like Figure 1 As shown, the floating shoe 100 also includes a guide head 9 disposed at the lower end of the housing 1. The guide head 9 is connected to the housing 1 via a connecting mechanism 8. Figure 1 and Figure 3 As shown, a wing plate 10 is provided on the outer side of the guide head 9. Multiple wing plates 10 can be provided, and these wing plates 10 are evenly distributed in the circumferential direction. Figure 3 In the illustrated embodiment, four winglets 10 are provided. More or fewer winglets 10 may be provided as needed. Figure 1As shown, the wing plate 10 can extend longitudinally downward relative to the guide head 9. In the event of an accidental bottoming of the liner, the wing plate 10 contacts the bottom of the well. A typical suspension device can be released by rotating the liner. At this time, there is significant friction between the wing plate 10 and the bottom of the well, which increases the success rate of releasing the suspension device by rotating the liner.

[0026] In addition, such as Figure 3 As shown, a second circulation hole 11 is provided at the center of the bottom end of the guide head 9. In addition, a third circulation hole 12 may be provided between adjacent wing plates 10.

[0027] The connecting mechanism 8 is configured to allow, and only allow, the guide head 9 to move relative to the housing 1 in one direction (the first direction, in...) Figure 2 (The direction is counterclockwise). Thus, during the lowering of the tailpipe into the well, the flange 10 can contact the well wall, which is laterally and downward relative to the float shoe 100. The flange 10 can guide the guide head 9. That is, when encountering resistance, the well wall and the flange 10 contact each other, and the force exerted by the well wall on the flange 10 causes the guide head 9, connected to the flange 10, to rotate relative to the housing 1. This rotation facilitates unblocking, allowing the tailpipe to continue lowering into the well.

[0028] like Figure 3 As shown, the wing 10 may have a helical profile. The direction of helical rotation is consistent with the desired direction of rotation of the guide head 9. This helical structure is beneficial for driving the guide head 9 to rotate.

[0029] Figure 2 The specific structure of the connecting mechanism 8 is shown. For example... Figure 2 As shown, the upper end of the guide head 9 is inserted into the lower end of the housing 1, forming a generally annular space between the guide head 9 and the housing 1. Multiple sets of stops 810, limiting blocks 820, and elastic elements 830 are arranged within this space. The limiting block 820 is located on one circumferential side of the stop block 810, more specifically, in the second direction (opposite to the first direction, in...). Figure 2 The elastic element 830 is located on one side of the stop block 810 (clockwise direction). The elastic element 830 is disposed on the other side of the stop block 810 in the circumferential direction, more specifically on one side in the first direction. This places the elastic element 830 between the stop block 810, the limit block 820 and the limit block 840 in the adjacent set of stop blocks, limit blocks and elastic elements.

[0030] The limiting block 820 is fixed relative to the housing 1. The limiting block 820 may be integral with the housing 1, or it may be fixedly connected to the housing 1 in an appropriate manner.

[0031] For example Figure 2As shown, a first meshing tooth 801 is provided on the outer circumferential side of the guide head 9. A second meshing tooth 811 is provided on the inner circumferential side of the stop block 810. The first meshing tooth 801 and the second meshing tooth 811 can mesh together. The first meshing tooth 801 and the second meshing tooth 811 can have an involute tooth shape, a circular arc tooth shape, a square tooth shape, or a pointed tooth shape, or they can be ratchet teeth or any other suitable teeth.

[0032] The elastic element 830 can be a helical spring or any other suitable elastic element.

[0033] The elastic element 830 is always in a compressed state. Therefore, in the initial state, the elastic element 830 can press the stop 810 against the limiting block 820. The surface of the limiting block 820 that contacts the stop 810 is the contact surface 821. In a preferred embodiment, the contact surface 821 is constructed as an inclined plane, radially inward along a second direction. Thus, when the elastic element 830 pushes the stop 810 against the contact surface 821 of the limiting block 820, the contact surface 821 can provide a radially inward thrust to the stop 810, thereby causing the second engaging tooth 811 on the stop 810 to tightly engage with the first engaging tooth 801 on the guide head 9.

[0034] When the guide head 9 is subjected to the action of the well wall, it has a direction relative to the shell 1 along the second direction ( Figure 2 When the guide head 9 tends to rotate clockwise, under the meshing action of the first meshing tooth 801 and the second meshing tooth 811, it tends to rotate along the second direction, causing the stop block 810 to rotate together. However, at this time, the stop block 810 abuts against the contact surface 821 of the limiting block 820. Therefore, the limiting block 820 prevents the stop block 810 from rotating in the second direction, thereby preventing the guide head 9 from rotating relative to the housing 1 in the second direction.

[0035] When the guide head 9 is subjected to the action of the well wall, it has a direction relative to the shell 1 along the first direction ( Figure 2 When the guide head 9 tends to rotate counterclockwise, under the meshing action of the first meshing tooth 801 and the second meshing tooth 811, the guide head 9 drives the stop block 810 to rotate together in the first direction, causing the stop block 810 to separate from the contact surface 821 of the limiting block 820, and causing the elastic element 830 to be further compressed. At this time, the stop block 810 is pushed by the elastic element 830, thereby returning to the state of abutting against the contact surface 821 of the limiting block 820. In this process, the first meshing tooth 801 and the second meshing tooth 811 first separate and then re-mesh at another angle. This process allows the guide head 9 to rotate relative to the housing 1 in the first direction. This rotation can be sustained and performed freely.

[0036] Through the above structure and working process, it is possible to allow only the guide head 9 to rotate in one direction relative to the housing 1. This is essential for the tailpipe lowering process. Because, during tailpipe lowering, reverse movement of the float shoe is generally not permitted to avoid unintended snagging, loss of control, or other operational errors.

[0037] exist Figure 2 In the preferred embodiment shown, the contact surface 821 is curved. The curvature of the contact surface 821 gradually increases along the second direction. Correspondingly, the portion of the stop 810 that mates with the contact surface 821 can have a corresponding curved profile. This structural arrangement is more conducive to radially inward pushing of the guide stop 810 to stably press it onto the guide head 9, ensuring a tighter engagement of the first meshing tooth 801 and the second meshing tooth 811. This helps ensure the stability of the unidirectional rotation of the guide head 9, thereby further preventing unintended snagging, slippage, or other operational issues with the tailpipe.

[0038] In one embodiment, the housing 1, guide head 9, limiting block 820, and stop block 810 are all made of a rigid material (e.g., steel). This improves the operational stability of the connection mechanism, thereby enhancing the operational stability of the float shoe. This is crucial for downhole operations in high-temperature, high-pressure, or even corrosive environments. It should be noted that in this case, the radial height of the stop block 810 should be less than the radial height of the annular gap between the housing 1 and the guide head 9, thus providing space for the separation of the first meshing tooth 801 and the second meshing tooth 811.

[0039] In another embodiment, the housing 1, guide head 9, and limiting block 820 are made of a rigid material (e.g., steel), while the stop block 810 can be made of an elastic material (e.g., rubber). When the guide head 9 rotates in the first direction, the elastic stop block 810 is compressed, causing the first engaging tooth 801 to separate from the second engaging tooth 811. This arrangement is advantageous for fine wells with limited space. In this case, the radial height of the stop block 810 does not need to be less than the radial height of the annular gap between the housing 1 and the guide head 9.

[0040] The float shoe 100 of this invention is applicable to tailpipe construction processes. It facilitates deblocking during tailpipe lowering. The float shoe 100 is suitable for vertical wells, horizontal wells, and inclined wells.

[0041] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

[0042] List of reference numerals

[0043] 1. Shell

[0044] 2 Cement body

[0045] 3. Check valve

[0046] 4. Sealing ring

[0047] 5 O-rings

[0048] 6 O-rings

[0049] 7 First circulation hole

[0050] 8. Connecting mechanism

[0051] 9. Guide Head

[0052] 10 wing plates

[0053] 11 Second circulation hole

[0054] 12 Third circulation hole

[0055] 801 First meshing tooth

[0056] 810 stop block

[0057] 811 Second meshing tooth

[0058] 820, 840 limit blocks

[0059] 821 Contact Surface

[0060] 830 Elastic component.

Claims

1. A float shoe for tailpipe cementing, comprising: A cylindrical shell, A guide head is provided at one end of the housing, and A connecting mechanism that connects the housing to the guide head and is configured to allow the guide head to rotate unidirectionally relative to the housing about the axis of the housing, the connecting mechanism comprising: The first engaging tooth is constructed on the radially outer side of the guide head; A stop block, radially disposed between the guide head and the housing, has a second meshing tooth disposed on its radially inner side, the second meshing tooth being configured to mesh with the first meshing tooth; and A limiting block is configured to push the stop block radially inward so that the second meshing tooth of the stop block engages with the first meshing tooth of the guide head. The limiting block protrudes radially inward relative to the housing and is fixedly connected to the housing. The limiting block is located on one side of the stop block in the circumferential direction. The limiting block has a contact surface facing the stop block. The contact surface is inclined inward along a second direction. The contact surface is a curved surface, and the curvature of the contact surface gradually increases along the second direction. When the guide head has a tendency to rotate in a first direction, the stop can move radially outward relative to the guide head to separate the first meshing tooth from the second meshing tooth, allowing the guide head to rotate relative to the housing in the first direction; When the guide head has a tendency to rotate in a second direction, the contact surface can act on the stop to keep the first meshing tooth and the second meshing tooth engaged, thereby preventing the guide head from rotating relative to the housing in a second direction, which is opposite to the first direction.

2. The float shoe for tailpipe cementing according to claim 1, characterized in that, A wing plate is constructed on the outer side of the guide head, the wing plate being configured to contact the wellbore wall to drive the guide head to rotate.

3. The float shoe for tailpipe cementing according to claim 2, characterized in that, The wing has a spiral profile.

4. The float shoe for tailpipe cementing according to claim 2 or 3, characterized in that, The guide head is constructed with multiple wing plates, which are evenly distributed in the circumferential direction.

5. The float shoe for tailpipe cementing according to any one of claims 1 to 3, characterized in that, The stop block, the limiting block, the guide head, and the housing are all made of rigid materials.

6. The float shoe for tailpipe cementing according to any one of claims 1 to 3, characterized in that, The connecting mechanism further includes an elastic element disposed circumferentially on the other side of the stop block, the elastic element being configured to push the stop block so that the stop block abuts against the contact surface.

7. The float shoe for tailpipe cementing according to claim 6, characterized in that, The connecting mechanism includes multiple sets of the stops, the limiting blocks, and the elastic elements, which are evenly distributed circumferentially. In one of the multiple groups, one end of the elastic element in one group is in contact with the stop block in the same group, and the other end is in contact with the limiting block in another adjacent group.

8. The float shoe for tailpipe cementing according to any one of claims 1 to 3, characterized in that, The first meshing tooth and the second meshing tooth have an involute tooth shape, a circular arc tooth shape, a square tooth shape, or a pointed tooth shape.

Images