A hydraulic jaw type tubing elevator

Abstract

The present invention relates to a tubing elevator, specifically to a hydraulic jaw-type tubing elevator, which is used to solve the problems that in the working condition where a ring power tong is fixed to the wellhead, due to the design of the existing tubing elevator, the coupling is located on the upper table surface of the elevator, and it is impossible to place the coupling at the position of the back-up tong, resulting in the ring power tong being unable to complete the make-up and break-out of the tubing, and in the upper suspension or lower suspension mode, when the tubing in the well is stuck and both the inner cavity and the outer ring cavity of the tubing are filled with sand, the traditional fishing tools cannot effectively fish. Compared with the lifting method in the prior art where the coupling is seated on the upper end surface of the tubing elevator, the jaws in the present invention can place the coupling at the position of the back-up tong under the ring power tong, ensuring that the back-up tong of the ring power tong can clamp the coupling to complete the make-up and break-out of the tubing, and the jaws in the present invention can extend into the large four-way at the wellhead to clamp the coupling tightly and lift out the stuck tubing.

Description

Technical Field

[0001] The present invention relates to a tubing elevator, and more particularly to a hydraulic jaw type tubing elevator. Background Art

[0002] During the process of tubing running and pulling operations, an open type power tong is usually used to perform the make-up and break-out operations between the tubing and the coupling. The traditional power tong needs to be pushed above the wellhead during operation to hold the tubing tightly, and then moved away after the make-up and break-out operations to clear the wellhead. However, to meet special operation requirements, there is also a ring type power tong currently, which is installed above the wellhead. During the make-up and break-out operations, the tubing moves up and down through its inner cavity, and the height of the back jaw of the ring type power tong remains unchanged. After the inner slip teeth of the master jaw hold the outer wall of the tubing tightly, it rotates circumferentially to complete the tubing make-up and break-out operation process.

[0003] As Figure 1 shown, this ring type power tong includes a master jaw 01 and a back jaw 02. The back jaw 02 is installed below the transition support disc 03, and its lower end is sequentially connected to a fixing plate 04, a pneumatic chuck 05, and the wellhead large four-way 010 or blowout preventer. The master jaw 01 is connected to the back jaw 02 in a floating manner and is located above the transition support disc 03. During the make-up and break-out operations, the back jaw 02 clamps the coupling 07, and the master jaw 01 clamps the tubing 08 and rotates to complete the make-up and break-out operations. Therefore, before the make-up and break-out operations, the coupling 07 needs to be placed in the position of the back jaw 02 first. However, since the existing tubing elevator is relatively large and its design makes the coupling 07 usually located above the tubing elevator, the coupling 07 cannot be directly placed into the back jaw 02.

[0004] In addition, the tubing suspension methods in the oilfield well are divided into two types: upper suspension and lower suspension.

[0005] Referring to Figure 2 , in the upper suspension method, the tubing 08 and the coupling 07 are suspended in the central hole of the upper flange 011 at the upper part of the wellhead large four-way 010 through a suspension nipple 09. When the tubing 08 is stuck in the well, since it cannot be directly lifted, the upper flange 011 needs to be removed first. However, since the thread between the suspension nipple 09 and the upper flange 011 is usually larger than the thread between the suspension nipple 09 and the coupling 07, the thread between the suspension nipple 09 and the coupling 07 will be unscrewed first when removing the upper flange 011. In this case, if the inner cavity 012 and the outer ring cavity 013 of the tubing are not filled with sand, a fishing spear or a fishing barrel can be used for fishing. However, when the inner cavity 012 and the outer ring cavity 013 of the tubing are filled with sand, for the slip teeth of the fishing spear or the fishing barrel to catch or hold the inner or outer wall of the tubing 08, it needs to be inserted more than 500 mm deep into the inside and outside of the mouth of the coupling 07. In this case of sand sticking, the stuck tubing 08 cannot be effectively fished directly.

[0006] Referring to Figure 3, in the lower suspension method, the tubing 08 is suspended in the through-hole of the large four-way 010 at the wellhead through the suspension head 014. The suspension head 014 is fixed by the setscrew 015 installed on the side wall of the large four-way 010 at the wellhead to prevent the tubing 08 from moving upward when there is pressure in the well. The lower part of the suspension head 014 is connected to the collar 07 and the tubing 08 through the suspension nipple 09. Similarly, since the thread between the suspension nipple 09 and the suspension head 014 is usually larger than the thread between the suspension nipple 09 and the collar 07, when the inner cavity 012 and the outer ring cavity 013 of the tubing are filled with sand, the fishing spear or fishing barrel cannot effectively fish due to limited depth. Summary of the Invention

[0007] The object of the present invention is to solve the problems that when the ring power tongs are fixed to the wellhead working condition, due to the existing design of the tubing elevator, the collar is located on the upper table surface of the elevator, and the collar cannot be placed in the position of the back-up tong, resulting in the ring power tongs being unable to complete the make-up and break-out operations, and in the upper suspension or lower suspension methods, when the tubing in the well is stuck and both the inner cavity and the outer ring cavity of the tubing are filled with sand, the traditional fishing tools (such as fishing spear or fishing barrel) cannot effectively fish. Therefore, a hydraulic jaw type tubing elevator is provided.

[0008] In order to solve the above deficiencies of the existing technology, the present invention provides the following technical solutions:

[0009] A hydraulic jaw type tubing elevator, which is characterized in that it includes a lift housing assembly, a hollow center rod assembly and a pull rod assembly;

[0010] The lift housing assembly includes a housing and an upper pressing cap; a housing through-hole is provided in the middle of the housing along the vertical direction; the upper pressing cap is arranged in the housing through-hole;

[0011] The hollow center rod assembly includes a hollow center rod and an annular hollow piston that are coaxially and slidably connected to each other from outside to inside; the upper end of the hollow center rod and the upper end of the annular hollow piston are both located in the housing through-hole and abut against the lower end of the upper pressing cap. Seals are provided between the upper end of the hollow center rod and the inner wall of the housing through-hole, and between the upper end of the hollow center rod and the annular hollow piston; the lower end of the hollow center rod is hinged with a plurality of circumferentially evenly distributed claws for clamping or loosening the collar;

[0012] The annular hollow piston is slidably sleeved on the pull rod assembly, and a return spring is provided between the outer side wall of the pull rod assembly and the inner hole wall of the annular hollow piston. The upper end and the lower end of the return spring respectively abut against the pull rod assembly and the annular hollow piston, and are used to provide an upward force for the pull rod assembly in the absence of hydraulic oil drive, so that the plurality of claws are in a clamped state;

[0013] A pipe release hydraulic chamber communicating with an external hydraulic pipeline is provided between the upper end of the annular hollow piston, the upper end of the pull rod assembly, and the lower end of the upper pressing cap. The pipe release hydraulic chamber is used to release the collar by loosening multiple jaws under the drive of hydraulic oil. A clamping hydraulic chamber communicating with the external hydraulic pipeline is provided between the annular hollow piston and the hollow central rod. The clamping hydraulic chamber is used to clamp the collar by tightening multiple jaws under the drive of hydraulic oil.

[0014] The axial length of the part of the hollow central rod located outside the through hole of the housing is greater than the distance between the bottom surface of the collar and the top surface of the large four-way joint at the wellhead, and its outer diameter is smaller than the inner diameters of the master tongs and the large four-way joint at the wellhead. The maximum outer diameter of the multiple jaws is smaller than the inner diameters of the master tongs and the large four-way joint at the wellhead.

[0015] Further, the hollow central rod includes a piston mounting section and a jaw mounting section connected to each other along the axis. The piston mounting section is sleeved on the annular hollow piston and is slidably connected to the annular hollow piston. The upper end of the piston mounting section abuts against the lower end of the upper pressing cap. A protrusion is provided along the axis at the lower end of the upper pressing cap. The protrusion extends into the central through hole of the piston mounting section, and the bottom surface of the protrusion abuts against the upper end of the annular hollow piston. A seal is provided between the protrusion and the inner wall of the central through hole of the piston mounting section.

[0016] The pipe release hydraulic chamber communicates with the external hydraulic pipeline through a second radial through hole provided on the upper pressing cap and a first radial through hole corresponding to the second radial through hole provided on the piston mounting section. The clamping hydraulic chamber communicates with the external hydraulic pipeline through a third radial through hole provided on the piston mounting section.

[0017] A plurality of circumferentially evenly distributed chutes are provided on the side wall of the jaw mounting section. Each chute extends axially and radially penetrates the side wall of the jaw mounting section. The multiple jaws are respectively hinged in the multiple chutes.

[0018] Further, each jaw includes an abutting section, a hinged section, a clamping section, and an inner hook section connected in sequence from top to bottom. An abutting outer inclined surface abutting against the lower end of the annular hollow piston is provided on the outer wall of the abutting section. An abutting inner inclined surface adapted to the abutting outer inclined surface is provided at the lower end of the annular hollow piston. A hinged through hole is provided in the horizontal direction on the hinged section. A hinge shaft for hinging the hinged section to the jaw mounting section is provided in the hinged through hole. The inner hook section is used to hook the lower annular table surface of the collar.

[0019] Further, a plurality of hinged blind holes corresponding to the multiple jaws are provided at the position of the jaw mounting section corresponding to the hinged section. Both ends of each hinge shaft are respectively located at the entrance and bottom end of the corresponding hinged blind hole, and the middle part is located in the corresponding hinged through hole.

[0020] Further, the number of the jaws is 4.

[0021] The four hinge shafts corresponding to the four jaws include two first hinge shafts that are symmetric to each other and two second hinge shafts that are symmetric to each other; one end of each of the first hinge shafts is fixed to the bottom end of the corresponding hinge blind hole, and the other end abuts against the end face of a second hinge shaft.

[0022] Further, the pull rod assembly includes a compression nut, a pull rod, an expansion sleeve, and a locking nut that are connected in sequence from top to bottom; the pipe release hydraulic cavity is arranged between the upper end of the annular hollow piston, the upper end of the compression nut, and the lower end of the upper pressing cap.

[0023] Further, the upper end of the expansion sleeve is in an outwardly convex spherical or conical shape.

[0024] Further, an inner piston ring groove is arranged along the radial direction on the inner wall of the annular hollow piston, a radial convex ring is arranged at the upper end of the pull rod, a spring cavity is formed between the bottom surface of the radial convex ring of the pull rod, the outer wall of the pull rod, and the inner wall of the piston inner ring groove, the return spring is arranged in the spring cavity, and the upper end and the lower end of the return spring respectively abut against the bottom surface of the radial convex ring of the pull rod and the bottom surface of the piston inner ring groove.

[0025] Further, an inner center rod ring groove is arranged along the radial direction on the inner wall of the hollow center rod;

[0026] An outer piston first ring groove and an outer piston second ring groove are arranged along the radial direction on the outer wall of the annular hollow piston, the sealing member is arranged in the outer piston first ring groove, and the clamping hydraulic cavity is formed between the outer piston second ring groove and the inner center rod ring groove.

[0027] Further, locking arms for connecting the lifting rings are arranged on both sides of the housing.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] (1) For the hydraulic jaw type tubing elevator of the present invention, the axial length of the part of the hollow center rod outside the through hole of the housing is greater than the distance between the bottom surface of the coupling and the top surface of the large four-way of the wellhead, its outer diameter is smaller than the inner diameters of the main tong, the back tong of the ring power tong, and the large four-way of the wellhead, and the maximum outer diameter formed after the installation and fixation of the multiple jaws is smaller than the inner diameters of the main tong, the back tong of the ring power tong, and the large four-way of the wellhead. Compared with the lifting method in the prior art where the coupling is seated on the upper end surface of the tubing elevator, the jaws in the present invention can place the coupling in the position of the back tong under the ring power tong, ensuring that the back tong of the ring power tong can clamp the coupling to complete the make-up and break-out of the tubing, and the jaws in the present invention can extend into the large four-way of the wellhead to clamp the coupling and lift out the clamped tubing.

[0030] (2) The clamping and loosening of the jaws of the present invention are both realized by hydraulic power, so they can be reliably implemented and also meet the need for remote control. At the same time, the present invention also completely has the function of a conventional elevator for grasping the surface tubing.

[0031] (3) In the present invention, the four jaws are respectively connected to the jaw mounting section through two first connecting shafts and two second connecting shafts, and the first connecting shaft and the second connecting shaft are locked with each other, improving the reliability of the present invention. Description of the Drawings

[0032] Figure 1 is a schematic structural view of a ring power tong fixed on a wellhead in the prior art;

[0033] Figure 2 is a schematic structural view of a hanging structure on an oil pipe in an oilfield well in the prior art;

[0034] Figure 3 is a schematic structural view of a lower hanging structure of an oil pipe in an oilfield well in the prior art;

[0035] Figures 1 - 3 Description of the reference numerals: 01 - main tong; 02 - back tong; 03 - transition support disc; 04 - fixing plate; 05 - pneumatic chuck; 07 - coupling; 08 - oil pipe; 09 - hanging nipple; 010 - large four-way wellhead; 011 - upper flange; 012 - inner cavity of the oil pipe; 013 - outer ring cavity; 014 - hanging head; 015 - setscrew.

[0036] Figure 4 is a schematic structural view of an embodiment of a hydraulic jaw type oil pipe elevator of the present invention;

[0037] Figure 5 is Figure 4 A - A sectional view of;

[0038] Figure 6 is Figure 4 B - B sectional view of;

[0039] Figure 7 is Figure 4 C - C sectional view of;

[0040] Figure 8 is a schematic structural view of the hollow central rod in the embodiment of the present invention;

[0041] Figure 9 is Figure 8 D - D sectional view of;

[0042] Figure 10 is Figure 8 E - E sectional view of;

[0043] Figure 11 is Figure 8 F - F sectional view of;

[0044] Figure 12 is the front view of the jaw in the embodiment of the present invention;

[0045] Figure 13 This is a side view of the jaw in the embodiment of the present invention;

[0046] Figure 14 This is a schematic structural diagram when the jaw in the embodiment of the present invention is loosened;

[0047] Figure 15 This is a schematic diagram of the state when the coupling is clamped and sent into the back-up tong in the embodiment of the present invention;

[0048] Figure 16 This is a schematic diagram of the state when the stuck tubing is released from the card in the embodiment of the present invention.

[0049] Figures 4 - 16 The description of the reference numerals is as follows:

[0050] 100 - elevating body assembly; 110 - body; 120 - upper compression cap;

[0051] 200 - hollow center rod assembly; 210 - hollow center rod; 211 - piston mounting section; 212 - jaw mounting section; 213 - chute; 215 - hinge blind hole; 216 - threaded hole; 217 - inner annular groove of the center rod; 220 - annular hollow piston; 221 - abutting inner inclined surface; 222 - inner annular groove of the piston; 223 - first outer annular groove of the piston; 224 - second outer annular groove of the piston;

[0052] 300 - pull rod assembly; 310 - compression nut; 320 - pull rod; 321 - radial projection of the pull rod; 330 - expanding sleeve; 340 - locking nut;

[0053] 4 - return spring;

[0054] 500 - jaw; 501 - abutting section; 502 - hinge section; 503 - clamping section; 504 - inner hook section; 505 - abutting outer inclined surface; 506 - hinge through hole; 507 - first hinge shaft; 508 - second hinge shaft;

[0055] 6 - locking arm; 7 - release hydraulic cavity; 8 - clamping hydraulic cavity; 91 - first radial through hole; 92 - second radial through hole; 10 - third radial through hole;

[0056] 01 - master tong; 02 - back-up tong; 03 - transition support disc; 05 - pneumatic chuck; 07 - coupling; 08 - tubing; 010 - wellhead four-way cross. Detailed implementation manners

[0057] The present invention will be further described below with reference to the accompanying drawings and exemplary embodiments.

[0058] Refer to Figures 4 to 7, a hydraulic jaw-type tubing elevator includes an elevator housing assembly 100, a hollow center rod assembly 200, a pull rod assembly 300, and multiple jaws 500. In this embodiment, the number of jaws 500 is 4.

[0059] The elevator housing assembly 100 includes a housing 110 and an upper pressing cap 120; on both sides of the housing 110, there are provided locking arms 6 for preventing the lower ring opening of the sling from falling off, and a housing through hole is provided in the middle along the vertical direction; the upper pressing cap 120 is arranged in the housing through hole and is located at the upper end, and the upper pressing cap 120 is threadedly connected to the inner wall of the housing through hole.

[0060] The hollow center rod assembly 200 includes an annular hollow piston 220 and a hollow center rod 210; the hollow center rod 210 includes a piston mounting section 211 and a jaw mounting section 212 that are connected to each other. The piston mounting section 211 is sleeved on the annular hollow piston 220 and is slidably connected to the annular hollow piston 220. The four jaws 500 are respectively hinged to the jaw mounting section 212 through four hinge shafts and are circumferentially evenly distributed.

[0061] Both the annular hollow piston 220 and the upper end of the piston mounting section 211 are located in the housing through hole and are in contact with the lower end of the upper pressing cap 120. The upper end of the piston mounting section 211 is in contact with the lower end of the upper pressing cap 120. A protrusion is arranged along the axial direction at the lower end of the upper pressing cap 120. The protrusion extends into the central through hole of the piston mounting section 211, and the bottom surface of the protrusion is in contact with the upper end of the annular hollow piston 220. A seal is arranged between the protrusion and the inner wall of the central through hole of the piston mounting section 211. Seals are arranged between the upper end of the piston mounting section 211 and the inner wall of the housing through hole, and between the upper end of the piston mounting section 211 and the annular hollow piston 220; the part of the piston mounting section 211 located outside the housing through hole and the jaw mounting section 212 have an axial length greater than the distance between the bottom surface of the coupling 07 and the top surface of the wellhead master cross-over 010, and an outer diameter smaller than the inner diameters of the master tong 01 and the wellhead master cross-over 010. The maximum outer diameter (the outer diameter when released) of the four jaws 500 is smaller than the inner diameters of the master tong 01 and the wellhead master cross-over 010, ensuring that the jaws 500 can place the coupling 07 into the back-up tong 02 when lifting the tubing 08, or can smoothly extend into the wellhead master cross-over 010 to catch the coupling 07 when the tubing 08 is stuck and needs to be salvaged.

[0062] The annular hollow piston 220 is sleeved on the pull rod assembly 300. The pull rod assembly 300 includes a compression nut 310, a pull rod 320, an outer expansion sleeve 330, and a locking nut 340 that are connected in sequence from top to bottom. The compression nut 310 and the pull rod 320 are threadedly connected. The upper end of the outer expansion sleeve 330 is in an outwardly convex spherical or conical shape, which is convenient for expanding the inner wall of the jaw 500.

[0063] The inner wall of the annular hollow piston 220 is provided with a piston inner ring groove 222 along the radial direction. The upper end of the pull rod 320 is provided with a pull rod radial convex ring 321. A spring cavity is formed between the bottom surface of the pull rod radial convex ring 321 and the inner wall of the piston inner ring groove 222. A return spring 4 is arranged in the spring cavity. The upper end and the lower end of the return spring 4 respectively abut against the bottom surface of the pull rod radial convex ring 321 and the bottom surface of the piston inner ring groove 222, and are used to provide an upward force for the pull rod 320 in the absence of hydraulic oil drive, so that the four claws 500 are in a clamped state.

[0064] A release hydraulic cavity 7 is arranged between the upper end of the annular hollow piston 220, the upper end of the compression nut 310 and the lower end of the upper pressing cap 120. The release hydraulic cavity 7 is communicated with the external hydraulic pipeline through a second radial through hole 92 arranged on the upper pressing cap 120 and a first radial through hole 91 arranged on the piston installation section 211. The release hydraulic cavity 7 is used to loosen the coupling 07 by the four claws 500 under the drive of hydraulic oil.

[0065] The inner wall of the hollow center rod 210 is provided with a center rod inner ring groove 217 along the radial direction; the outer wall of the annular hollow piston 220 is provided with a piston first outer ring groove 223 and a piston second outer ring groove 224 along the radial direction. The piston first outer ring groove 223 is used to arrange a sealing ring. A clamping hydraulic cavity 8 is formed between the piston second outer ring groove 224 and the center rod inner ring groove 217. The clamping hydraulic cavity 8 is communicated with the external hydraulic pipeline through a third radial through hole 10 arranged on the piston installation section 211. The clamping hydraulic cavity 8 is used to hook the coupling 07 by the four claws 500 under the drive of hydraulic oil.

[0066] Refer to Figures 8 to 11 , the side wall of the claw installation section 212 is an arc surface and is provided with four circumferentially evenly distributed chutes 213. Each chute 213 extends axially and radially penetrates the side wall of the claw installation section 212. The four claws 500 are respectively hinged in the four chutes 213.

[0067] Refer to Figures 4 - 7 , Figures 12 - 13 , each of the claws 500 includes an abutting section 501, a hinged section 502, a clamping section 503 and an inner hooking section 504 which are connected in sequence from top to bottom; the abutting section 501 abuts against the lower end of the annular hollow piston 220, and the inner hooking section 504 is used to hook the lower annular table surface of the coupling 07.

[0068] An abutting outer inclined surface 505 for abutting against the lower end of the annular hollow piston 220 is provided on the outer wall of the abutting section 501, and an abutting inner inclined surface 221 adapted to the abutting outer inclined surface 505 is provided at the lower end of the annular hollow piston 220; an articulated through hole 506 is provided in the articulated section 502 in the horizontal direction, and four articulated blind holes 215 corresponding to the four jaws 500 are provided at the corresponding position of the jaw mounting section 212. Both ends of each articulated shaft are respectively located at the entrance and bottom end of the corresponding articulated blind hole 215, and the middle part is located in the corresponding articulated through hole 506.

[0069] To prevent the articulated shaft from falling off, the four articulated shafts include two symmetric first articulated shafts 507 and two symmetric second articulated shafts 508; threaded holes 216 communicating with each other are provided at the bottom ends of the corresponding articulated blind holes 215 of the two first articulated shafts 507. One end of each first articulated shaft 507 is fixed to the bottom end of the corresponding articulated blind hole 215 through the threaded hole 216, and the other end abuts against the end face of a second articulated shaft 508 to prevent the second articulated shaft 508 from loosening.

[0070] The working principle of this embodiment is as follows:

[0071] Refer to Figure 14 and Figure 15 When this embodiment is used in cooperation with the annular power tong, taking the lowering of the tubing 08 as an example (that is, when the coupling 07 needs to be placed into the back-up tong 02):

[0072] Step 1: Open the locking arm 6, lock it after connecting with the lifting ring; then hook this embodiment onto the coupling 07.

[0073] Step 2: Lift this embodiment and the tubing 08 together and lower them into the well. The jaws 500 drive the pipe string to pass through the master tong 01, the transition support disc 03 and the back-up tong 02 in sequence. After entering the pneumatic chuck 05, then enter the well.

[0074] Step 3: Supply air to the pneumatic chuck 05 to make it clamp the tubing 08.

[0075] During this process, since the outer diameter of the part of this embodiment located outside the housing through hole is smaller than the inner diameters of the master tong 01, the transition support disc 03 and the back-up tong 02, and its length ensures that the jaws 500 can smoothly place the coupling 07 into the back-up tong 02, therefore, it can be ensured that the coupling 07 on the tubing 08 is located inside the back-up tong 02.

[0076] Step 4: Supply liquid to the unlocking hydraulic cavity 7, and the pull rod 320 and the locking nut 340 drive the jaws 500 to contract and reset, release the coupling 07, and lift this embodiment upward to complete the process of lowering the tubing 08. The operation is simple and safe and reliable.

[0077] Refer to Figure 14 and Figure 16, this embodiment is used to release the stuck tubing 08:

[0078] Step 1. After the tubing 08 suspended in the upper flange of the wellhead master cross joint 010 by the upper suspension method is stuck, first remove the upper flange and the suspension head; after the tubing 08 suspended in the upper flange of the wellhead master cross joint 010 by the lower suspension method is stuck, first remove the upper flange, the suspension head and the suspension nipple. After removal, the coupling 07 is located in the through hole of the wellhead master cross joint 010.

[0079] Step 2. Open the lock arm 6 and connect it with the sling of the workover equipment and then lock it. Lift this embodiment and lower it into the well. Since under the action of the return spring 4, when there is no hydraulic oil driving, the claw 500 is always in the clamping state. Therefore, when the claw 500 enters the through hole of the wellhead master cross joint 010 and is located at the preset position, first supply oil to the release hydraulic cavity 7. The lower port of the claw 500 expands outward and drops to cover the outside of the coupling 07. Then supply oil to the clamping hydraulic cavity 8. The claw 500 swings along the hinge axis, the upper part expands outward, the lower inner hook section 504 retracts and hooks the lower annular table surface of the coupling 07. Lifting this embodiment can lift and release the stuck tubing 08.

[0080] Since the sum of the neck length of this embodiment (the length of the hollow center rod 210 extending out of the housing 110) and the length of the claw mounting section 212 is greater than the distance between the bottom surface of the coupling 07 and the top surface of the wellhead master cross joint 010, the claw 500 can smoothly extend into the through hole of the wellhead master cross joint 010 to surround and clamp the coupling 07. Even if the inner cavity or the outer ring cavity of the tubing 08 is filled with sand, it does not affect its function.

Claims

1. A hydraulic claw type tubing elevator, characterized in that: It comprises an elevator housing assembly (100), a hollow center rod assembly (200) and a pull rod assembly (300); The hanging card housing assembly (100) comprises a housing (110) and an upper pressure cap (120); a housing through hole is arranged in the middle of the housing (110) along the vertical direction; and the upper pressure cap (120) is arranged in the housing through hole; The hollow center rod assembly (200) comprises a hollow center rod (210) and an annular hollow piston (220) which are coaxially and slidably connected from the outside to the inside; the upper ends of the hollow center rod (210) and the annular hollow piston (220) are both located in the through hole of the shell and abut against the lower end of the upper pressure cap (120); seals are provided between the upper end of the hollow center rod (210) and the inner wall of the through hole of the shell, and between the upper end of the hollow center rod (210) and the annular hollow piston (220); the lower end of the hollow center rod (210) is hinged with a plurality of claws (500) evenly distributed in the circumferential direction, which are used to clamp or loosen the coupling (07); The annular hollow piston (220) is slidably sleeved on the tie rod assembly (300), and a return spring (4) is arranged between the outer wall of the tie rod assembly (300) and the inner hole wall of the annular hollow piston (220), and the upper end and the lower end of the return spring (4) respectively abut against the tie rod assembly (300) and the annular hollow piston (220), so as to provide an upward force for the tie rod assembly (300) in the absence of hydraulic oil drive, so that the multiple claws (500) are in a clamped state; A release hydraulic chamber (7) connected to an external hydraulic pipeline is provided between the upper end of the annular hollow piston (220), the upper end of the pull rod assembly (300) and the lower end of the upper pressure cap (120), and the release hydraulic chamber (7) is used to enable multiple claws (500) to loosen the coupling (07) under the drive of hydraulic oil; a clamping hydraulic chamber (8) connected to an external hydraulic pipeline is provided between the annular hollow piston (220) and the hollow center rod (210), and the clamping hydraulic chamber (8) is used to enable multiple claws (500) to clamp the coupling (07) under the drive of hydraulic oil; The hollow center rod (210) is located outside the through hole of the shell, and its axial length is greater than the distance between the bottom surface of the coupling (07) and the top surface of the wellhead large cross (010), and its outer diameter is smaller than the inner diameters of the main clamp (01) and the wellhead large cross (010); the maximum outer diameter of the plurality of claws (500) is smaller than the inner diameters of the main clamp (01) and the wellhead large cross (010).

2. The hydraulic claw type tubing elevator according to claim 1, characterized in that: The hollow center rod (210) comprises a piston mounting section (211) and a claw mounting section (212) which are connected to each other along the axial direction; the piston mounting section (211) is sleeved on the annular hollow piston (220) and is slidably connected to the annular hollow piston (220); the upper end of the piston mounting section (211) abuts against the lower end of the upper pressure cap (120); a protrusion is axially arranged at the lower end of the upper pressure cap (120); the protrusion extends into the central through hole of the piston mounting section (211), and the bottom surface of the protrusion abuts against the upper end of the annular hollow piston (220); a sealing member is arranged between the protrusion and the inner wall of the central through hole of the piston mounting section (211); The unblocking hydraulic chamber (7) is connected to an external hydraulic pipeline via a second radial through hole (92) provided on the upper pressure cap (120) and a first radial through hole (91) provided on the piston mounting section (211) and corresponding to the second radial through hole (92); the clamping hydraulic chamber (8) is connected to an external hydraulic pipeline via a third radial through hole (10) provided on the piston mounting section (211); The side wall of the clamping claw installation section (212) is provided with a plurality of sliding grooves (213) uniformly distributed in the circumferential direction, each sliding groove (213) extends axially and radially penetrates the side wall of the clamping claw installation section (212), and the plurality of clamping claws (500) are respectively hinged in the plurality of sliding grooves (213).

3. The hydraulic claw type tubing elevator according to claim 2, characterized in that: Each of the clamping claws (500) comprises an abutting section (501), an articulated section (502), a clamping section (503) and an inner hook section (504) which are sequentially connected from top to bottom; the outer wall of the abutting section (501) is provided with an abutting outer inclined surface (505) which abuts against the lower end of the annular hollow piston (220), and the lower end of the annular hollow piston (220) is provided with an abutting inner inclined surface (221) which matches the abutting outer inclined surface (505); the articulated section (502) is provided with an articulated through hole (506) in the horizontal direction, and an articulated shaft for articulating the articulated section (502) to the clamping claw mounting section (212) is provided in the articulated through hole (506); the inner hook section (504) is used to hook the lower annular table surface of the coupling (07).

4. The hydraulic claw type tubing elevator according to claim 3, characterized in that: A plurality of hinge blind holes (215) corresponding to the plurality of claws (500) are provided at the corresponding positions of the claw installation section (212) and the hinge section (502); the two ends of each hinge shaft are respectively located at the entrance and the bottom end of the corresponding hinge blind hole (215), and the middle part is located in the corresponding hinge through hole (506).

5. The hydraulic claw type tubing elevator according to claim 4, characterized in that: The number of the claws (500) is 4; The four hinge axes corresponding to the four claws (500) include two mutually symmetrical first hinge axes (507) and two mutually symmetrical second hinge axes (508); one end of each of the first hinge axes (507) is fixed to the bottom end of the corresponding hinge blind hole (215), and the other end is abutted against the end face of a second hinge axis (508).

6. A hydraulic claw type tubing elevator according to any one of claims 1 to 5, characterized in that: The pull rod assembly (300) comprises a clamping nut (310), a pull rod (320), an outer expansion sleeve (330), and a locking nut (340) which are sequentially connected from top to bottom; the unblocking hydraulic chamber (7) is arranged between the upper end of the annular hollow piston (220), the upper end of the clamping nut (310), and the lower end of the upper pressure cap (120).

7. The hydraulic claw type tubing elevator according to claim 6, characterized in that: The upper end of the outer expansion sleeve (330) is in an outwardly convex spherical or conical shape.

8. The hydraulic claw type tubing elevator according to claim 6, characterized in that: The inner wall of the annular hollow piston (220) is radially provided with a piston inner ring groove (222); the upper end of the pull rod (320) is provided with a pull rod radial convex ring (321); a spring cavity is formed between the bottom surface of the pull rod radial convex ring (321), the outer wall of the pull rod (320) and the inner wall of the piston inner ring groove (222); the return spring (4) is arranged in the spring cavity; the upper end and the lower end of the return spring (4) respectively abut against the bottom surface of the pull rod radial convex ring (321) and the bottom surface of the piston inner ring groove (222).

9. The hydraulic claw type tubing elevator according to claim 6, characterized in that: The inner wall of the hollow center rod (210) is provided with a center rod inner annular groove (217) along the radial direction; The outer wall of the annular hollow piston (220) is radially provided with a first outer ring groove (223) and a second outer ring groove (224). The sealing element is arranged in the first outer ring groove (223). The clamping hydraulic chamber (8) is formed between the second outer ring groove (224) and the inner ring groove (217) of the center rod.

10. The hydraulic claw type tubing elevator according to claim 6, characterized in that: Locking arms (6) for connecting to lifting rings are provided on both sides of the housing (110).

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