Wellhole fishing tool

Abstract

A wellbore fishing tool (1) configured for engaging and withdrawing downhole remnants in a subterranean well comprises an actuation motor (5) and an actuation member (23) operated by the actuation motor in an axial direction. It further comprises an engagement assembly (10), wherein the engagement assembly (10) has a body (17), a gripping element (13) configured to be movable between a non-engaged state and an engaged state, and said actuating member (23) between the actuator motor (5) and the gripping element (13). The gripping element (13) is connected to the actuating member (23) via a connection hinge (29).

Description

Technical Field

[0001] The invention relates to a wellbore fishing tool with a novel design. Background Art

[0002] Various types of wellbore fishing tools are known. Many wellbore fishing tools use a set of flexible arms to move a gripping element between an engaged state and a disengaged state to engage and disengage a fish / downhole debris inside a wellbore.

[0003] An example of such a fishing tool is described in WO2019035726, in which a set of flexible arms bend or flex by engaging with a tapered surface.

[0004] The object of the present invention is to provide a fishing tool capable of receiving large-diameter fallen fish / underground remains.

[0005] Another object is to provide a fishing tool that can grasp small downhole debris even if its receiving diameter is large.

[0006] In some cases, in addition to the downhole relic, there may be a cable, which is usually present together with the engagement interface of the downhole relic. Such a cable may inadvertently become loose, so that it falls down and partially falls on the side of the downhole relic. This will increase the thickness, so the fishing tool will need additional capacity to engage the downhole relic. Therefore, conventional fishing tools may not be able to engage the downhole relic. One object of the present invention is to provide a fishing tool that can engage the downhole relic even when the cable is arranged together with the downhole relic.

[0007] Another purpose is to enable the fishing tool to be released from the downhole relic after engaging the downhole relic. This function is usually beneficial in the following situations: the downhole relic is stuck in the well and the fishing tool cannot pull the downhole relic.

[0008] Another object is to provide a fishing tool that can also be used as a running tool for a variety of other wellbore tools.

[0009] Furthermore, an even further object is to provide a fishing tool that can engage a wellbore downhole remnant without applying an axial force to the downhole remnant to initiate engagement. Summary of the invention

[0010] According to the present invention, a wellbore fishing tool is provided, which is configured to engage and recover fish / downhole debris in a subterranean well. The fishing tool includes an actuating motor and an actuator member operated in an axial direction by the actuating motor. The wellbore fishing tool also includes an engagement assembly, wherein the engagement assembly includes: a body; a gripping element configured to move between a non-engaged state and an engaged state; and the actuating member between the actuator motor and the gripping element. The gripping element is connected to the actuating member via a connecting hinge.

[0011] Various embodiments and advantageous features appear in the dependent claims.

[0012] The term "subterranean well" refers to both onshore and underwater wells.

[0013] The term "connecting hinge" means that the two elements connected via the connecting hinge are two different independent parts, which can rotate relative to each other. Therefore, according to this definition, a curved flexible element is not within the scope of this definition.

[0014] As the reader of the art should be clear, the term "via a connecting hinge" means that the connecting hinge is arranged between the gripping element and the actuating member. Therefore, additional elements may also be arranged between the gripping element and the actuating member to transmit the actuating force between the two components.

[0015] Advantageously, the joint assembly may be springless. Springless joint assembly means that the movement of the gripping element between the non-engaged state and the engaged state is not based on a bending component of the joint assembly. However, in other embodiments, the joint assembly may be provided with a spring. Thus, in addition to the connecting hinge, the joint assembly may also include a spring.

[0016] Preferably, the actuating member comprises an actuating arm parallel to the longitudinal direction of the wellbore fishing tool.In some embodiments, the actuating arm is embedded in an arm slot arranged in the body.

[0017] In some embodiments, the engagement assembly further comprises an actuation link connected to the actuation member via a first connection hinge and connected to the gripping element via a second connection hinge. This solution enables a translational and partially radial movement of the gripping element between a non-connected state and a connected state. The actuation member can be moved in an axial direction to transmit a movement force to the gripping element via the actuation link.

[0018] In some embodiments, as will be described in further detail below, the engagement assembly may have only two second inclined guide end surfaces, wherein the flat planes of the two second inclined guide end surfaces are symmetrical about the axially extending center line.

[0019] Preferably, the second sliding end faces also extend along respective flat planes.These planes of the respective second inclined guide end face and the respective second sliding end face may advantageously be parallel.

[0020] Advantageously, when in said non-engaged state, the respective actuation link may be at least partially disposed within the respective arm slot.

[0021] Notably, the wellbore fishing tools discussed herein can be manufactured without elastic springs, which are commonly used in existing solutions. Instead, solid / solid components are used that can move between non-engaged and engaged states without relying on bending of the components. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Having generally discussed various features of the present invention above, some more detailed non-limiting embodiments will now be described with reference to the accompanying drawings, in which:

[0023] Figure 1 is a perspective view of a portion of a wellbore fishing tool according to the present invention;

[0024] Figure 2 It passes through Figure 1 A cutaway side view of a fishing tool;

[0025] Figure 3 is a schematic diagram of downhole legacy located in a well (not shown);

[0026] Figure 4 , Figure 5 and Figure 6 is a cross-sectional side view showing movement from a non-engaged state to an engaged state;

[0027] Figure 7 and Fig. 9 are perspective views showing a non-engaged state and an engaged state, respectively;

[0028] Figure 8 and Fig.10 They correspond to Figure 7 and Fig. 9 Front view of the situation shown;

[0029] Fig.11 and Fig.12 are different perspective views with the gripping elements removed for illustration purposes;

[0030] Fig.13 is a cut-away side view of a portion of a wellbore fishing tool; and

[0031] Fig.14 is a perspective view of the actuator element and the actuating member. DETAILED DESCRIPTION

[0032] Figure 1 A wellbore fishing tool 1 according to an embodiment of the present invention is depicted. The fishing tool 1 comprises an actuating device 3, which comprises an actuator motor 5. The actuator motor 5 is Figure 2 In the embodiment shown, the actuator motor 5 is an electric motor. However, the actuator motor 5 may also be of any other suitable type, such as a hydraulic motor.

[0033] The actuator motor 5 is configured to provide a linear movement of the actuator element 7 .

[0034] In the embodiment shown, the actuator motor 5 is connected to the actuator element 7 via a mechanical connection structure 9. The mechanical connection structure 9 that transmits the actuating movement between the actuator motor 5 and the actuator element 7 can be designed in various ways. One such design is described in the publication WO2019035726. In the embodiment in which the actuator motor 5 is a rotary motor, the mechanical connection structure 9 includes a rotary-to-linear converter 6.

[0035] Figure 2 An axially extending centre line A is shown.

[0036] The fishing tool 1 has an engagement assembly 10 at its front portion, which is configured to engage a downhole relic 15 ( Figure 3 ).

[0037] By operating the actuator motor 5 , the actuator element 7 can be moved forwards and backwards along the axial extension direction of the fishing tool 1 .

[0038] exist Figure 2 The cross-sectional side view of the outer housing 11 is shown for illustration purposes. Figure 1 The outer shell 11 is omitted.

[0039] The fishing tool 1 further comprises a gripping element 13. The gripping element 13 is configured to be movable radially inwardly to engage with downhole debris 15 within the wellbore. As will be discussed in more detail below, the gripping element 13 is actuated by operation of the actuator motor 5.

[0040] Figure 3 A downhole relic 15 is schematically shown. The downhole relic 15 has a trumpet-shaped end portion facing the tool. In other words, the downhole relic 15 may usually have been damaged, so that in order to retrieve the downhole relic 15, the fishing tool 1 must be able to grip on the trumpet-shaped end portion to firmly grip the downhole relic 15.

[0041] In another case, for example, the downhole debris may have different diameters, so the fishing tool 1 must move over the large diameter portion of the downhole debris to engage with the small diameter portion of the downhole debris.

[0042] Figures 4 to 6 The engagement assembly 10 of the wellbore fishing tool 1 is depicted as it moves toward, receives, and engages with a downhole remnant 15 within a wellbore (not shown).

[0043] exist Figure 4 In the process, the fishing tool 1 moves toward the downhole relic 15. For example, the downhole relic 15 can be a damaged pipe end, wherein the end has been squeezed to be substantially flat, so that the size of the end is significantly larger than the outer diameter of the pipe.

[0044] The fishing tool 1 has two gripping elements 13. The gripping elements 13 have gripping surfaces 13a facing inwards. The gripping surfaces 13a may advantageously be provided with a serration or toothed surface for enhanced engagement with the outer surface of the downhole remnant 15.

[0045] Preferably, the gripping surface 13a has a curved shape, such as Fig.10 As shown in the front view.

[0046] Figure 4 The front part of the fishing tool 1 shown has a body 17. The body 17 has a front hole 19 through which the downhole relic 15 passes when the downhole relic 15 is received in the fishing tool 1.

[0047] Figure 5 FIG. 1 shows the salvage tool 1 in a state where underground debris 15 has entered the salvage tool 1. Figure 5 As shown, the fishing tool 1 comprises an abutment end surface 21 against which the downhole remains 15 abut.

[0048] The fishing tool 1 also has an actuating member, in the embodiment shown in the form of two actuating arms 23. The actuating members, ie the actuating arms 23, are connected to the actuator element 7 and can therefore be moved forwards and backwards together with the actuator element 7.

[0049] The actuating arm 23 extends parallel to the axial extension direction of the fishing tool 1. Furthermore, the actuating arm is arranged in an arm slot 25 of the main body 17.

[0050] At the front portion, the actuating arms 23 are connected to the respective actuating links 27 via first connecting hinges 29 .

[0051] The actuating link 27 is further connected to the corresponding gripping element 13 via a second connecting hinge 31 .

[0052] Advantageously, the first connection hinge 29 may include a first connection hinge pin 29a. Furthermore, the second connection hinge 31 may include a second connection pin 31a.

[0053] The gripping element 13 is arranged between the first inclined guide end surface 33 and the second inclined guide end surface 35. In the embodiment shown, the first and second inclined guide end surfaces 33, 35 are part of the body 17. Furthermore, the first and second inclined guide end surfaces 33, 35 are parallel to each other.

[0054] The first inclined guide end face 33 and the second inclined guide end face 35 both extend in a flat plane. In other words, these end faces have no curves (extend only in two dimensions). It should be clear that in other embodiments, the first and / or second guide end faces 33, 35 may include a curved shape. In addition, in other embodiments, they do not need to be parallel to each other.

[0055] In addition, the gripping element 13 includes a first sliding end surface 37 and a second sliding end surface 39. The first sliding end surface 37 abuts against the first guide end surface 33, while the second sliding end surface 39 abuts against the second guide end surface 35. As those skilled in the art will understand by viewing the drawings, the sliding end surfaces 37, 39 are configured to slide against the guide end surfaces 33, 35 when the actuating arm 23 is actuated back and forth.

[0056] like Figure 6 As shown, when the actuator arm 23 moves forward, the gripping element 13 slides along the opposite and parallel first and second guide end faces 33, 35. This movement of the gripping element 13 continues until they contact the downhole relic 15. Once the gripping element 13 has contacted the downhole relic 15, the entire wellbore fishing tool 1 is pulled upward (i.e., toward the top of the well not shown). Then, the second sliding end face 39 will engage with the second guide end face 35, which causes the radially inward force of the gripping element 13 on the downhole relic 15 to increase. This provides a secure engagement between the fishing tool 1 and the downhole relic 15, and the downhole relic 15 can now be pulled up.

[0057] By comparison Figure 5 and Figure 6 It can be seen that in Figure 6 In the embodiment, the downhole relic 15 is inserted less relative to the position of the fishing tool 1. When the downhole relic 15 is inserted into the fishing tool 1 and collides with the abutment end face 21, the downhole relic has moved a distance in the opposite direction as the gripping element 13 engages the surface of the downhole relic 15.

[0058] It is worth noting that the actuation link 27 rotates relative to the actuation arm 23 about the first connection hinge 29. The actuation link 27 also pivots relative to the gripping element 13 about the second connection hinge 31. It is worth noting that in the embodiment shown, the gripping element 13 does not pivot. Instead, the gripping element 13 moves only by a translational movement.

[0059] It should also be noted that when the gripping element 13 is Figure 4 The non-engaged state shown and Figure 6 When moving between the illustrated engagement states, no bending occurs. This differs from known solutions in which the gripping element would normally be arranged at the end of a flexible bending arm.

[0060] See also Figure 6 , a pulling gap 8a is shown between a portion of the actuating arm 23 and a portion of the actuator element 7. As described above, in this case, the gripping element 13 is configured to engage with the downhole relic 15. When the wellbore fishing tool 1 starts to pull the downhole relic 15, the gripping element 13 may be slightly pressed into the material of the downhole relic 15. During this engagement-enhancing movement, the pulling gap 8a will ensure that the pulling force can still be transmitted through the body 17, rather than through the actuating arm 23.

[0061] Similarly, in Figure 4 In FIG. 8 , a push gap 8b is shown, which enables the push gap 8a to be provided when engaging the downhole legacy 15 .

[0062] Figure 7 and Fig. 9 Depicted in perspective Figure 4 and Figure 6 For illustration purposes, Figure 7 and Fig. 9 The downhole remains 15 and the outer shell 11 are omitted.

[0063] Figure 8 and Fig.10 The previous view shows the Figure 7 and Fig. 9 The salvage tool 1 and the underground remains 15 in the corresponding state. Figure 8 , a damaged end portion of a downhole relic 15 is shown.

[0064] Although Fig.10 The embodiment shown is configured to grip on the cylindrical portion of the downhole remnant 15, but the gripping element 13 may be designed differently. For example, the gripping surfaces 13a may be arranged so that they abut against each other in the engaged state. As will be understood by those skilled in the art, the gripping surfaces 13a will then extend radially inwardly beyond the portion of the gripping element 13 that abuts against the landing end surface 34.

[0065] like Figure 7 and Fig. 9 As shown, a landing end surface 34 is provided between the first inclined guide end surface 33 and the second inclined guide end surface 35. In the embodiment shown, the landing end surface 34 is a part of the main body 17.

[0066] When the gripping elements 13 move radially inwards the maximum distance, they collide with their respective landing end faces 34 and stop moving. In the embodiment shown, the landing end faces 34 extend axially, ie parallel to the longitudinal extension direction of the engagement assembly 10.

[0067] The illustrated embodiment involves four landing surfaces 34 , wherein each pair of landing surfaces 34 defines a force transfer rod 36 between each pair of landing surfaces 34 .

[0068] Fig.11 and Fig.12 The body 17 is depicted in different perspective views in order to better illustrate the first and second guide end surfaces 33, 35 and the landing end surface 34. Fig.12 As shown, the first inclined guide end surface 33 is interrupted by the arm groove 25 .

[0069] It should be noted that when the downhole relic 15 is pulled, most of the pulling force is not transmitted through the actuating arm 23 and the actuating link 27. Instead, the force is transmitted from the downhole relic 15 through the gripping element 13 and into the body 17 via the second guide end surface 35. In particular, the pulling force is transmitted through the two force transmission rods 36. Therefore, the dimensions of the actuating arm 23 and the actuating link 27 only need to be designed to actuate the gripping element 13 from the non-engaged state to the engaged state.

[0070] At the front end portion of the fishing tool 1 there is a front sleeve 41 attached to the body 17. The front sleeve 41 has an inwardly facing conical end face 41a which is flush with the conical end face 17a of the body 17.

[0071] like Fig.11 and Fig.12 As shown in the perspective view of FIG. 1 , the main body 17 is tubular or cylindrical and has an inner hole 17b.

[0072] Fig.13 A portion of a wellbore fishing tool 1 is depicted without the engagement assembly 10 . Fig.14 The actuator element 7 is shown with an actuator arm 23 connected thereto.

[0073] Although the above embodiments all include only two gripping elements 13, it should be clear to those skilled in the art that other embodiments may include more gripping elements, such as three or four gripping elements 13. The two gripping elements 13 of the above embodiments are distributed 180 degrees apart. Embodiments involving three gripping elements 13 may advantageously be distributed 120 degrees apart, while embodiments with four gripping elements 13 may be distributed 90 degrees apart. As known to those skilled in the art, this angular distribution also applies to the corresponding inclined guide end faces and sliding end faces.

Claims

1. A wellbore fishing tool (1) configured to engage and retrieve downhole debris in a subterranean well, the wellbore fishing tool comprising an actuating motor (5) and an actuating member (23) operated in an axial direction by the actuating motor, and further comprising an engagement assembly (10), wherein the engagement assembly (10) comprises a body (17), a gripping element (13) configured to be movable between a non-engaged state and an engaged state, and the actuating member (23) between the actuator motor (5) and the gripping element (13), It is characterized in that The gripping element (13) is connected to the actuating member (23) via a connecting hinge (29).

2. The wellbore fishing tool (1) according to claim 1, characterized in that: The engagement assembly (10) further comprises an actuation link (27), wherein the respective actuation link (27) is connected to the actuation member (23) via a first connection hinge (29) and to the gripping element (13) via a second connection hinge (31).

3. The wellbore fishing tool (1) according to claim 1 or 2, characterized in that: The engagement assembly (10) further comprises a first inclined guide end surface (33) and a second inclined guide end surface (35), and the corresponding gripping element (13) comprises a first sliding end surface (37) sliding against the first inclined guide end surface and a second sliding end surface (39) sliding against the second inclined guide end surface.

4. The wellbore fishing tool (1) according to claim 3, characterized in that: The first inclined guide end surface (33) faces forward and radially outward, the second inclined guide end surface (35) faces rearward and radially inward, and the second inclined guide end surface (35) extends along a corresponding flat plane.

5. The wellbore fishing tool (1) according to claim 4, characterized in that: The corresponding first inclined guide end surface (33) and the corresponding first sliding end surface (37) are flat and parallel to the corresponding second inclined guide end surface (35).

6. A wellbore fishing tool (1) according to claims 2 and 3 or according to claims 2 and 3 and claim 4 or 5, characterized in that The actuating member (23) includes two actuating arms, the main body (17) includes arm slots (25) for receiving the actuating arms, and the corresponding arm slots (25) interrupt the corresponding first inclined guide end surfaces (33).

7. A wellbore fishing tool (1) according to claim 3 or according to claim 3 and any other preceding claim, characterized in that The coupling assembly (10) further comprises two pairs of landing end surfaces (34), wherein each pair of landing end surfaces comprises parallel landing end surfaces (34) arranged on opposite sides of a force transmission rod (36), and the force transmission rod is arranged between the first inclined guide end surface (33) and the second inclined guide end surface (35).

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