Lost tool mechanism and completion string for an inflatable liner hanger

Abstract

The present application provides a lost-hand mechanism and a completion string for an inflatable liner hanger. The lost-hand mechanism includes a first joint connected to a running string, a lower end of the first joint being configured with a plurality of circumferentially spaced engagement teeth; a second joint connected to a tieback, an upper end of the second joint being configured with a plurality of circumferentially spaced engagement slots corresponding to the engagement teeth for receiving the engagement teeth, the engagement teeth and the engagement slots cooperating to enable a twist of the running string to be transmitted to the tieback; and a clamping assembly configured to connect the first joint and the second joint together by a clamping fit and to enable the first joint and the second joint to be separated upon lost-hand.

Description

Technical Field

[0001] This invention relates to the field of cementing and completion technology for oil and gas wells, specifically to a release mechanism for an expandable tailpipe hanger. The invention also relates to a cementing and completion tubing string incorporating the aforementioned release mechanism. Background Technology

[0002] During the cementing and completion process of oil and gas wells, the tailpipe needs to be sent into the well using a delivery tool, and then the delivery tool and tailpipe are separated by a release mechanism to leave the tailpipe downhole.

[0003] In existing technology centers, tailpipes are typically mounted and sealed within the outer sleeve using tailpipe hangers to maintain their position and provide a foundation for subsequent cementing and oil and gas extraction.

[0004] The most commonly used liner hanger is the slip-type hanger, although expansion hangers have emerged in recent years. However, both slip-type and expansion hangers utilize a back-threaded release mechanism, requiring the release of the liner through uncoupling the back-threaded threads. The drawback of this release method is that, during uncoupling, the drill string must be lifted and precisely positioned to find the neutral point of the longitudinal force. This is a significant operational challenge. Furthermore, this back-threaded structure prevents the entire tubing string from twisting during lowering; otherwise, premature release may occur. In such cases, if the tubing string encounters obstruction during lowering, there is a lack of effective means to handle the blockage. This leads to low operational efficiency and may also cause unexpected premature activation of components such as shear studs and retaining rings within the tubing string. This could prevent subsequent cementing and completion operations. Summary of the Invention

[0005] To address the technical problems described above, this invention proposes a release mechanism that can solve or at least mitigate at least one of the aforementioned problems. This invention also proposes a cementing completion string including the aforementioned release mechanism.

[0006] According to a first aspect of the present invention, a release mechanism is provided, comprising: a first connector connected to an input tube, the lower end of the first connector having a plurality of circumferentially spaced engagement teeth; a second connector connected to a return tube, the upper end of the second connector having a plurality of circumferentially spaced engagement grooves, the engagement grooves corresponding to the engagement teeth for receiving the engagement teeth, the engagement teeth and engagement grooves cooperating to transmit torsion of the input tube to the return tube; and a snap-fit ​​assembly configured to connect the first connector and the second connector together by snap-fit ​​engagement, and to allow the first connector and the second connector to separate upon release.

[0007] The aforementioned release mechanism replaces the reverse threaded connection with a snap-fit ​​connection, enabling the transmission of torsion through the engagement of the teeth and grooves. This allows for the mitigation of obstruction and stuck-hole issues during tubing string lowering into the well via torsion, thus improving lowering efficiency and preventing premature actuation of structures within the tubing string. Furthermore, the snap-fit ​​release mechanism eliminates the need to locate a neutral point during release, simplifying the release operation.

[0008] In one embodiment, the inner wall of the second connector is provided with a first snap-fit ​​groove. The snap-fit ​​assembly includes: a first snap-fit ​​sleeve, the first snap-fit ​​sleeve including a connecting portion configured to connect to the first connector, the first snap-fit ​​sleeve further including a first elastic claw extending longitudinally downward from the connecting portion, the end of the first elastic claw being provided with a first snap-fit ​​protrusion extending radially outward, the first snap-fit ​​protrusion being configured to be accommodated within the first snap-fit ​​groove; and an extension sleeve, the upper end of the extension sleeve being connected to the connecting portion, the lower end of the extension sleeve extending longitudinally downward, the extension sleeve being sleeved within the second connector, forming an annular space between the second connector and the extension sleeve. A first resilient claw of the sleeve extends into the annular space and is spaced apart from the outer wall of the extended sleeve; and a second engaging sleeve includes a second resilient claw extending longitudinally upward, the end of which is configured with a second engaging protrusion extending radially outward, the second engaging protrusion extending between the first resilient claw and the extended sleeve; wherein, in a first state, the second engaging protrusion abuts against the first engaging protrusion and the extended sleeve to retain the first engaging protrusion within the first engaging groove; in a second state, the second engaging protrusion and the first engaging protrusion are longitudinally offset to allow the first engaging protrusion to disengage from the first engaging groove, thereby achieving release.

[0009] In one embodiment, the second snap-fit ​​sleeve includes a sealing portion that slides and seals with the outer wall of the extension sleeve and the inner wall of the second connector within the annular space, and the second elastic claw extends longitudinally upward from the sealing portion; wherein, in the second state, fluid can enter the annular space from the extension sleeve to push the sealing portion upward, thereby causing the second snap-fit ​​protrusion to be longitudinally misaligned with the first snap-fit ​​protrusion.

[0010] In one embodiment, in the second state, the lower end of the extension sleeve is an open end to allow fluid to enter the annular space from the extension sleeve.

[0011] In one embodiment, in a first state, the second snap-fit ​​sleeve is connected to the extension sleeve by a shear pin.

[0012] In one embodiment, a second snap-fit ​​groove is formed on the inner wall of the first snap-fit ​​sleeve; in a second state, the second snap-fit ​​protrusion is longitudinally offset from the first snap-fit ​​protrusion and snaps into the second snap-fit ​​groove.

[0013] In one embodiment, a snap-fit ​​boss is formed on the outer wall of the extension sleeve, and the snap-fit ​​surface of the snap-fit ​​boss is longitudinally upward; the second snap-fit ​​sleeve is formed with a snap-fit ​​engagement part that mates with the snap-fit ​​boss, and the snap-fit ​​engagement part mates with the snap-fit ​​boss to prevent the second snap-fit ​​sleeve from moving longitudinally downward relative to the extension sleeve.

[0014] In one embodiment, the engaging portion is configured as a third engaging protrusion extending radially inward from the end of the second resilient claw.

[0015] In one embodiment, the snap-fit ​​boss is constructed as a toothed buckle.

[0016] According to a second aspect of the present invention, a cementing completion string is provided, comprising: an input tubing string; a return sleeve; and the aforementioned release mechanism; wherein the return sleeve includes a narrowed portion with a radially inwardly converging diameter, and a setting and sealing portion for engaging with an outer sleeve is constructed on the outer wall of the narrowed portion; the cementing completion string further includes an expansion cone, the expansion cone being sleeved outside the first connector; in a first state, the expansion cone is located longitudinally below the narrowed portion; in a second state, by lifting the input tubing string, the expansion cone moves longitudinally upward relative to the return sleeve, and under the action of the expansion cone, the narrowed portion expands radially outward, so that the setting and sealing portion engages with the outer sleeve. Attached Figure Description

[0017] The present invention will now be described with reference to the accompanying drawings.

[0018] Figure 1 A schematic diagram of a release mechanism for an expandable tailpipe suspension according to an embodiment of the present invention is shown, the release mechanism being in a first state.

[0019] Figure 2 Showing Figure 1 A schematic diagram of the dropping mechanism in its second state.

[0020] Figure 3 Showing Figure 1 A schematic perspective view of the first connector in the drop mechanism.

[0021] Figure 4 Showing Figure 3 A schematic front view of the first connector in the diagram.

[0022] Figure 5 Showing Figure 1 A schematic structural diagram of the second connector in the drop mechanism.

[0023] Figure 6 Showing Figure 1 A schematic structural diagram of the first locking sleeve in the release mechanism.

[0024] Figure 7 Showing Figure 1 A schematic structural diagram of the second locking sleeve in the release mechanism.

[0025] In the accompanying drawings, the same parts are referred to by the same reference numerals. All drawings in this application are schematic and are used only to illustrate the principles of the invention, and are not drawn to scale. Detailed Implementation

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

[0027] In this article, "longitudinal" refers to the direction extending along the wellbore. "Longitudinal upward" is the direction toward the wellhead. "Longitudinal downward" is the direction toward the bottom of the well.

[0028] All threaded connections used in this article are positive threads in the same direction.

[0029] like Figure 1 As shown, a mounting mechanism 100 according to an embodiment of the present invention includes a first connector 110 connected to a feed string (e.g., a drill pipe) 400, which is generally constructed as a hollow cylindrical shape. The first connector 110 and the feed string 400 can be a threaded connection or any other suitable form of connection. Figure 3 and Figure 4 As shown, the lower end of the first connector 110 is provided with a plurality of engaging teeth 111. The plurality of engaging teeth 111 are evenly spaced apart in the circumferential direction. Figure 3 In the illustrated embodiment, four engagement teeth 111 are provided. It should be understood that more or fewer engagement teeth may be provided as needed.

[0030] The first connector 110 may further include a longitudinally upward first limiting step 112. A sealing engagement surface 113 is formed above the first limiting step 112. The expansion cone 300 of the expansion tailpipe hanger can be sleeved on the sealing engagement surface 113 and sealed with the sealing engagement surface 113. The longitudinal position of the expansion cone 300 is defined by the first limiting step 112 and the feed string 400, so that the expansion cone 300 is longitudinally fixed relative to the first connector 110.

[0031] The mounting mechanism 100 also includes a second connector 120. The upper end of the second connector 120 is connected to the return sleeve 200, and the lower end is connected to the tailpipe column 500. The connection between the second connector 120 and the return sleeve 200 and the tailpipe column 500 can be threaded, or it can be any other suitable form of connection. Figure 5 As shown, the upper end of the second connector 120 is constructed with a plurality of circumferentially spaced engagement grooves 121. Each engagement groove 121 corresponds to a corresponding engagement tooth 111, such that the engagement tooth 111 can be inserted into the engagement groove 121. The side edge of the engagement groove 121 can define the circumferential position of the engagement tooth 111. Thus, when the engagement tooth 111 is inserted into the engagement groove 121 (i.e., Figure 1 In the first state shown, the torsion of the feed string 400 and the first connector 110 can be transmitted to the second connector 120, the return sleeve 200, and the tailpipe string 500 through the engagement teeth 111 and the engagement groove 121.

[0032] In addition, Figure 1 In the first state shown, the bottom edge 121A of the engagement groove 121 can abut against the engagement tooth 111 to transmit longitudinal pressure.

[0033] In addition, such as Figure 1 As shown, a first engaging groove 122 is also formed on the inner wall of the second connector 120. This first engaging groove 122 is used to engage with the first engaging protrusion 131 of the first engaging sleeve 130 (described below). It will be described in more detail below.

[0034] The seat-hanging mechanism 100 also includes a snap-fit ​​assembly. The snap-fit ​​assembly includes a first snap-fit ​​sleeve 130. The first snap-fit ​​sleeve 130 includes a connecting portion, the upper end of which is connected to a first connector 110. The connection between the first snap-fit ​​sleeve 130 and the first connector 110 can be threaded, or it can be any other suitable form of connection. Figure 6 As shown, the first snap-fit ​​sleeve 130 also includes a plurality of first elastic snap-fit ​​claws 133 extending longitudinally downward from the connecting portion. The plurality of first elastic snap-fit ​​claws 133 are arranged spaced apart from each other in the circumferential direction. The ends of the first elastic snap-fit ​​claws 133 are configured with radially outwardly extending first snap-fit ​​protrusions 131. (As shown...) Figure 1 As shown, in the first state, the first snap-fit ​​protrusion 131 can be received by the first snap-fit ​​groove 122 on the inner wall of the second connector 120, thereby achieving a snap-fit ​​engagement between the first snap-fit ​​protrusion 131 and the first snap-fit ​​groove 122. With the first snap-fit ​​protrusion 131 and the first snap-fit ​​groove 122 engaged, a connection can be established between the second connector 120 and the first snap-fit ​​sleeve 130, thereby achieving a connection between the feed tube 400 and the return tube 200 and the tail tube 500. When the first snap-fit ​​protrusion 131 disengages from the first snap-fit ​​groove 122 (see...), Figure 2The connection between the second connector 120 and the first snap-fit ​​sleeve 130 is broken, thereby separating the feed string 400 from the return sleeve 200 and the tail pipe string 500.

[0035] exist Figure 1 and Figure 6 In the preferred embodiment shown, the longitudinally upward surface of the first snap-fit ​​protrusion 131 is inclined, and the corresponding mating surface of the first snap-fit ​​groove 122 is also inclined. This facilitates the disengagement of the first snap-fit ​​protrusion 131 from the first snap-fit ​​groove 122.

[0036] For example Figure 1 As shown, the snap-fit ​​assembly also includes an extension sleeve 140. The upper end of the extension sleeve 140 is connected to the lower end of the connecting portion of the first snap-fit ​​sleeve 130, and its lower end extends longitudinally downward. It should be understood that, as needed, the lower end of the snap-fit ​​sleeve 130 can connect to a corresponding structure found in conventional insertion tools, such as a cementing plug. The extension sleeve 140 is fitted inside the second connector 120. An annular space is formed between the second connector 120 and the extension sleeve 140. Figure 1 In the first state shown, the first elastic claw of the first snap sleeve 130 can extend downward into the annular space and fit against the inner wall of the second connector 120 while being spaced apart from the outer wall of the extension sleeve.

[0037] Additionally, the seat-mounting mechanism 100 also includes a second locking sleeve 150. For example... Figure 1 and Figure 7 As shown, the second snap-fit ​​sleeve includes a plurality of second resilient snap-fit ​​claws 153 that are spaced apart from each other in the circumferential direction and extend longitudinally upward. The ends of the second resilient snap-fit ​​claws 153 are provided with radially outward extending second snap-fit ​​protrusions 151. Additionally, the ends of the second resilient snap-fit ​​claws 153 are also provided with radially inward extending third snap-fit ​​protrusions 154. The third snap-fit ​​protrusion 154 is disposed opposite to the second snap-fit ​​protrusions 151. Figure 1 As shown, in the first state, the second snap-fit ​​protrusion 151 and the third snap-fit ​​protrusion 154 can extend between the first snap-fit ​​protrusion 131 of the first elastic claw 133 and the extension sleeve 140. Thus, they can form a support between the first snap-fit ​​protrusion 131 and the extension sleeve 140, forcing the first snap-fit ​​protrusion 131 to remain within the first snap-fit ​​groove 122 of the second connector 120, forming an effective snap-fit ​​fixation. At this time, the second snap-fit ​​sleeve 150 can be connected to the extension sleeve 140 via the shear pin 160 to ensure the stability and effectiveness of the aforementioned snap-fit ​​fixation.

[0038] In addition, such as Figure 1 and Figure 7As shown, the second snap-fit ​​sleeve 150 also includes a sealing portion 152 extending radially to form a sliding seal between the second connector 120 and the extension sleeve 140. This sealing portion 152 is connected to the lower end of the second resilient claw 153. In other words, the second resilient claw 153 is formed by the sealing portion 152 extending longitudinally upwards. Figure 2 In the second state shown, fluid can enter the annular space below the sealing part 152 from the extension sleeve 140, thereby pushing the sealing part 152 longitudinally upward. Under this pushing action, the shear pin 160 cuts, and the second snap-fit ​​sleeve 150 moves longitudinally upward as a whole, causing the second snap-fit ​​protrusion 151 and the third snap-fit ​​protrusion 154 to be misaligned with the first snap-fit ​​protrusion 131. In this case, the radially inner side of the first snap-fit ​​protrusion 131 is no longer supported, and can therefore easily disengage from the first snap-fit ​​groove 122 to achieve release. In addition, as the second snap-fit ​​sleeve 150 moves longitudinally upward, the second snap-fit ​​protrusion 151 can enter the second snap-fit ​​groove 132 located on the inner wall of the first snap-fit ​​sleeve 150, thereby restricting the longitudinal position of the second snap-fit ​​sleeve 150 and preventing it from moving unintentionally longitudinally downward, which would hinder release. Alternatively or additionally, a snap-fit ​​boss (not shown) can be provided on the outer wall of the extension sleeve 140, with the snap-fit ​​surface of the boss facing longitudinally upward. The aforementioned third snap-fit ​​protrusion 154 can engage with the snap-fit ​​protrusion of the snap-fit ​​boss when the first snap-fit ​​sleeve 150 moves longitudinally upward, thereby preventing unintended longitudinal downward movement of the second snap-fit ​​sleeve 150. The snap-fit ​​boss can be designed as a toothed, ratchet, or similar structure. The third snap-fit ​​protrusion 154 is constructed to engage accordingly.

[0039] In one embodiment, a bypass hole may be constructed on the sidewall of the extension sleeve 140 to connect the annular space below the seal 152 with the space inside the extension sleeve 140.

[0040] In a preferred embodiment, in the second state, the lower end of the extension sleeve 140 forms an open end to allow fluid to flow into the annular space. It should be understood that the formation of an open end at the lower end of the extension sleeve 140 does not preclude the possibility that other structures are connected below the extension sleeve 140 without impeding the flow of fluid from the lowermost end.

[0041] This invention also proposes a cemented well completion string including the aforementioned release mechanism 100. The following will be combined with... Figure 1 and Figure 2 The structure and working process of this cemented well completion string are described in detail.

[0042] First, the aforementioned release mechanism 100, tailpipe string 500, return sleeve 200, feed string 400, and expansion cone 300 are assembled together to form a cemented well completion tubing string, which is then run into the wellbore. The structure at this point is as follows: Figure 1 The first state is shown. The lower end of the extension sleeve 140 can be connected to structures found in other existing cementing and completion tubing strings, such as cementing plugs. During the running-in process, in case of unexpected situations such as sticking or obstruction, the operator can rotate the runner string 400 at the surface to allow the return sleeve 200, the second connector 120, and the tailpipe string 500 to rotate together through the engagement of the engagement teeth 111 and the engagement groove 121, thereby facilitating unsticking. Alternatively, in the event of sticking or obstruction, the runner string 400 can be pressed down to transfer longitudinal pressure to the return sleeve 200, the second connector 120, and the tailpipe string 500 through the engagement of the engagement teeth 111 and the bottom edge 121A of the engagement groove 121, thereby facilitating unsticking. Furthermore, the runner string 400 can also be lifted up. At this point, the longitudinal tension can be transmitted to the return sleeve 200, the second connector 120, and the tailpipe string 500 through the cooperation of the first engaging protrusion 131 and the first engaging groove 122. This also helps to handle complex downhole conditions and prevent the expansion hanger from setting prematurely.

[0043] After the cemented tubing string is inserted into position, pressure can be applied downhole via the insertion string 400 to shear the shear pin 160 and push the second clamping sleeve 150 longitudinally upward. As the second clamping sleeve 150 moves, the cemented tubing string... Figure 1 The first state transforms into Figure 2 The second state. At this point, the first engaging protrusion 131 and the first engaging groove 122 separate, allowing the feed string 400 and the first connector 110 to move upwards relative to the return sleeve 200. Continuing to lift the feed string 400, the expansion cone 300 outside the first connector 110 moves longitudinally upwards while radially pushing the narrowed portion 201 of the return sleeve 200 outwards. The outer wall of the narrowed portion 201 is provided with a sitting and sealing portion (this sitting and sealing portion is existing in the art, for example, a rubber part). Thus, the return sleeve 200 can sit and seal on the outer sleeve. Continuing to lift the feed string 400 allows it and part of the feed tool to be retrieved to the ground.

[0044] After that, subsequent cementing and completion operations can be carried out.

[0045] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and does not constitute any limitation on the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0046] List of reference numerals

[0047] Figure Labels Structure name 100 Dropping organization 110 First connector 111 Engaging teeth 112 First limiting step 113 Sealing joint surface 120 Second connector 121 joint groove 121A Second limiting step 122 First snap-fit ​​groove 130 First snap-fit ​​sleeve 131 First snap-fit ​​protrusion 132 Second snap-fit ​​groove 133 First elastic gripper 140 extension sleeve 150 Second clip sleeve 151 Second snap-fit ​​protrusion 152 Sealing part 153 Second elastic claw 154 Third connector protrusion 160 Clippers 200 return tube 201 Narrowing section 300 Expansion cone 400 Feeding the tubing 500 Tailpipe string

Claims

1. A dropping mechanism, comprising: The first connector connected to the feed string has a plurality of circumferentially spaced engagement teeth at its lower end. A second connector connected to the return tube has a plurality of circumferentially spaced engagement grooves at its upper end. The engagement grooves correspond to the engagement teeth for receiving the engagement teeth. The engagement teeth and engagement grooves cooperate to transmit the torsion of the feed tube to the return tube. as well as A snap-fit ​​assembly is configured to connect the first connector and the second connector together through a snap-fit ​​engagement, and to allow the first connector and the second connector to separate when released. The inner wall of the second connector has a first snap-fit ​​groove. The snap-fit ​​assembly includes: The first snap-fit ​​sleeve includes a connecting portion configured to connect with the first connector. The first snap-fit ​​sleeve also includes a first elastic claw extending longitudinally downward from the connecting portion. The end of the first elastic claw is configured with a first snap-fit ​​protrusion extending radially outward. The first snap-fit ​​protrusion is configured to be accommodated in the first snap-fit ​​groove. An extension sleeve, the upper end of which is connected to the connecting portion, and the lower end of which extends longitudinally downward, is fitted inside the second connector, forming an annular space between the second connector and the extension sleeve. A first elastic claw of the first engaging sleeve extends into the annular space and is spaced apart from the outer wall of the extension sleeve. The second snap-fit ​​sleeve includes a second elastic claw extending longitudinally upward. The end of the second elastic claw is provided with a second snap-fit ​​protrusion extending radially outward. The second snap-fit ​​protrusion can extend between the first elastic claw and the extension sleeve. The second snap-fit ​​sleeve includes a sealing part. The sealing part slides and seals with the outer wall of the extension sleeve and the inner wall of the second connector within the annular space. The second elastic claw extends longitudinally upward from the sealing part. In the first state, the second snap-fit ​​sleeve and the extension sleeve are connected by a scissor pin, and the second snap-fit ​​protrusion abuts between the first snap-fit ​​protrusion and the extension sleeve to keep the first snap-fit ​​protrusion in the first snap-fit ​​groove. In the second state, the lower end of the extension sleeve is an open end, allowing fluid to enter the annular space from the extension sleeve. The fluid can enter the annular space from the extension sleeve to push the sealing part upward, thereby causing the second snap-fit ​​protrusion to be longitudinally misaligned with the first snap-fit ​​protrusion, so as to allow the first snap-fit ​​protrusion to disengage from the first snap-fit ​​groove, thereby achieving release.

2. The release mechanism according to claim 1, characterized in that, A second snap-fit ​​groove is constructed on the inner wall of the first snap-fit ​​sleeve; In the second state, the second snap-fit ​​protrusion is longitudinally offset from the first snap-fit ​​protrusion and snaps into the second snap-fit ​​groove.

3. The release mechanism according to claim 1 or 2, characterized in that, A snap-fit ​​boss is constructed on the outer wall of the extension sleeve, and the snap-fit ​​surface of the snap-fit ​​boss faces longitudinally upward. The second snap-fit ​​sleeve is configured with a snap-fit ​​engagement portion that mates with the snap-fit ​​boss. The snap-fit ​​engagement portion mates with the snap-fit ​​boss to prevent the second snap-fit ​​sleeve from moving longitudinally downward relative to the extension sleeve.

4. The release mechanism according to claim 3, characterized in that, The engaging portion is constructed as a third engaging protrusion extending radially inward from the end of the second elastic claw.

5. The release mechanism according to claim 3, characterized in that, The snap-fit ​​protrusion is constructed as a toothed buckle.

6. A cemented well completion string, comprising: Insert the tubing; Return tube; as well as The release mechanism according to any one of claims 1 to 5; The return sleeve includes a narrowed portion with a radially inwardly tapering diameter. A mounting and sealing part for cooperating with the outer sleeve is constructed on the outer wall of the narrowed portion. The solidified well casing string also includes an expansion cone, which is sleeved outside the first joint. In the first state, the expansion cone is located longitudinally below the narrowed portion. In the second state, by lifting the feed tube, the expansion cone moves longitudinally upward relative to the return tube. Under the action of the expansion cone, the narrowed portion expands radially outward so that the seated sealing part engages with the outer sleeve.

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