Protective device for drilling liner hanger of oil and gas well

Abstract

The utility model discloses an oil and gas well tail pipe hanger protection device, which relates to the technical field of petroleum drilling tools, and comprises a sand prevention cover assembly and a fastening assembly, the sand prevention cover assembly comprises a conical thread locking block, a centralizing unit, a conical sealing head, a milling groove and a centralizing rib; balls are rotationally installed in the centralizing ribs, and the balls make contact with a rock debris bed to roll, so that the friction resistance generated when the sand prevention cover assembly descends and rotates is reduced. The centralizing units provided with the balls are arranged, the balls make contact with a cuttings bed in a rolling mode, upward thrust borne by the sand prevention cover assembly is greatly reduced, the sand prevention cover can be tightly matched with a tie-back barrel in the drilling liner hanger tripping-in process, the sand prevention cover assembly is prevented from being pushed away from the tie-back barrel by friction resistance in the tripping-in process, and meanwhile the sand prevention cover assembly is prevented from being separated from the tie-back barrel. In the later horizontal rotation operation process, the balls can roll freely, the good small-friction-resistance state is kept, and through the arrangement of the combined centralizing unit structure, the balls can be conveniently installed and assembled.

Description

Oil and gas well tailpipe suspension protection device Technical Field

[0001] This utility model relates to the field of oil drilling tool technology, specifically to a protective device for oil and gas well tailpipe hangers. Background Technology

[0002] In oil drilling engineering, the tailpipe hanger is a key tool for tailpipe cementing. The tailpipe hanger mainly includes the hanger body assembly, the return sleeve, the delivery tool assembly, and the sealing assembly. The main function of the return sleeve is to facilitate the insertion of the return plug into the return sleeve when the casing is reconnected later, so as to achieve effective sealing of the entire pipe string and ensure the integrity of the wellbore. In order to prevent solid particles from entering the inside of the tailpipe hanger return sleeve during tailpipe cementing and to prevent the delivery tool assembly from being stuck by solid particles, a sand-proof mechanism is often designed on the top of the return sleeve to work in conjunction with the delivery tool assembly. This sand-proof mechanism is usually called a "sand cap".

[0003] According to Chinese announcement number CN207229048U, a sand-proof cap for a tailpipe hanger reconnection cylinder is disclosed, comprising: a body, which is a hollow cylinder; a conical fastener disposed at the first end of the body, the conical fastener having multiple axial openings; the outer wall of the conical fastener having locking external threads, and the inner wall having locking teeth; and a straightening cylinder disposed at the second end of the body. This invention can prevent the sand-proof cap from moving during the lowering of the tailpipe hanger and the lifting and lowering of the movable pipe column when encountering obstacles, thus preventing the sand from being exposed at the reconnection cylinder's flared opening and causing solid particles to enter the reconnection cylinder and causing sand jamming. In this design, there is a situation where the frictional resistance between the sand-proof cap and the cuttings bed is too large during the lowering process.

[0004] According to announcement number CN207829833U, a sand guard for a tailpipe hanger reconnection cylinder is disclosed, comprising: a sand guard body, which is a hollow cylindrical structure; a straightening rib, disposed on the outer periphery of the sand guard body, the straightening rib having a roller groove; and a roller, which is rotatably installed in the roller groove. This invention, during the lowering process of the tailpipe hanger, transforms the sliding friction experienced by the sand guard in traditional structures into rolling friction through the sliding of the roller, greatly reducing the upward thrust experienced by the sand guard. This invention has a simple structure, can be varied in form, has strong applicability, and can be used in conjunction with other types of sand guard mechanisms to reduce construction risks.

[0005] In the above scheme, the friction of lowering is reduced by setting rollers. However, the rollers are horizontally distributed, which causes the rollers to be unable to rotate during horizontal rotation operations, and the friction between the rollers and the cuttings bed increases. Based on this, a protective device for the tailpipe hanger of an oil and gas well is provided. Summary of the Invention

[0006] The purpose of this utility model is to provide a protective device for oil and gas well tailpipe hangers in order to solve the problems mentioned above.

[0007] To achieve the above objectives, this utility model provides the following technical solution: a protective device for a tailpipe hanger in an oil and gas well, comprising a sand-proof cover assembly and a fastening assembly, wherein the sand-proof cover assembly comprises a tapered threaded locking block, a straightening unit, a tapered sealing head, a milled groove, and a straightening rib;

[0008] The tapered threaded locking block, the straightening unit, and the tapered sealing head are connected sequentially from top to bottom. Multiple milling grooves and straightening ribs are provided, and multiple milling grooves and straightening ribs are arranged in annular staggered distribution on the outside of the straightening unit.

[0009] The centering rib is equipped with rotatable ball bearings that protrude from the outside of the centering rib. The ball bearings roll in contact with the rock cuttings bed to reduce the frictional resistance during the lowering and rotation of the sand cover assembly.

[0010] As a further embodiment of this utility model: the straightening unit is composed of a connecting cylinder, a lower hollow cylinder, an upper hollow cylinder, and a hemispherical groove;

[0011] The tapered threaded locking block is fixed to the top of the connecting cylinder, the lower hollow cylinder is fixed to the bottom of the connecting cylinder, and the tapered sealing head is fixed to the bottom of the lower hollow cylinder;

[0012] The upper hollow cylinder is sleeved on the outside of the connecting cylinder, and the milled groove and the straightening rib are formed on the outside of the lower hollow cylinder and the upper hollow cylinder;

[0013] The hemispherical grooves are symmetrically opened on the upper surface of the lower hollow cylinder and the lower surface of the upper hollow cylinder. When the upper hollow cylinder and the lower hollow cylinder are in contact with each other, the two hemispherical grooves form a spherical groove for the ball bearings to be limited and rolled.

[0014] As a further embodiment of this utility model: the outer side of the connecting cylinder is formed with a snap-fit ​​strip, and the inner side of the upper hollow cylinder is formed with a snap-fit ​​groove;

[0015] The number of hemispherical grooves, snap-fit ​​strips, and snap-fit ​​slots is the same and there are multiple of them. The multiple hemispherical grooves and snap-fit ​​strips are distributed alternately along the circumference, and the position of the snap-fit ​​slot corresponds one-to-one with the hemispherical groove.

[0016] As a further improvement of this utility model: the fastening assembly includes an internal tapered threaded sleeve and an anti-loosening triangular ratchet;

[0017] Multiple anti-loosening triangular ratchet teeth are provided, and the multiple anti-loosening triangular ratchet teeth are fixed to the bottom of the inner conical thread sleeve. Multiple circumferentially distributed triangular grooves are formed on the upper surface of the upper hollow cylinder.

[0018] When the inner tapered threaded sleeve and the tapered threaded locking block are screwed together, the anti-loosening triangular ratchet engages with the inner side of the triangular slot to achieve the locking operation of the inner tapered threaded sleeve.

[0019] As a further embodiment of this utility model: the tapered threaded locking block, connecting cylinder, snap-fit ​​strip, lower hollow cylinder, hemispherical groove, tapered sealing head, milled groove, and straightening rib are integrally formed;

[0020] The upper hollow cylinder, snap-fit ​​groove, hemispherical groove, triangular snap-fit ​​groove, milled groove, and straightening rib are integrally formed;

[0021] The internal tapered threaded sleeve and the anti-loosening triangular ratchet are integrally formed.

[0022] Compared with the prior art, the beneficial effects of this utility model are:

[0023] By installing a centering unit with ball bearings, the ball bearings roll in contact with the cuttings bed, greatly reducing the upward thrust on the sand shield assembly. This ensures a tight fit between the sand shield and the return cylinder during the lowering of the tailpipe hanger, preventing frictional resistance from pushing the sand shield assembly away from the return cylinder. At the same time, the ball bearings can roll freely during the subsequent horizontal rotation operation, maintaining a good state of low frictional resistance. Furthermore, the modular centering unit structure facilitates the installation and assembly of the ball bearings. Attached Figure Description

[0024] Figure 1 is a schematic diagram of the structure of this utility model;

[0025] Figure 2 is a schematic diagram showing the disassembly of the fastening component and the sandproof cover component of this utility model;

[0026] Figure 3 is a schematic diagram of the disassembled sandproof cover assembly of this utility model.

[0027] In the diagram: 1. Sandproof cover assembly; 101. Tapered threaded locking block; 102. Straightening unit; 103. Tapered sealing head; 104. Milled groove; 105. Straightening rib; 2. Ball bearing; 3. Fastening assembly; 301. Internal tapered threaded sleeve; 302. Anti-loosening triangular ratchet.

[0028] 1021. Connecting cylinder; 1022. Snap-fit ​​strip; 1023. Lower hollow cylinder; 1024. Upper hollow cylinder; 1025. Hemispherical groove; 1026. Snap-fit ​​groove; 1027. Triangular snap-fit ​​groove. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] Please refer to Figures 1-3. In this embodiment of the utility model, the protective device for the tailpipe hanger of the oil and gas well includes a sand cover assembly 1 and a fastening assembly 3. The sand cover assembly 1 includes a tapered threaded locking block 101, a straightening unit 102, a tapered sealing head 103, a milled groove 104, and a straightening rib 105.

[0031] The tapered threaded locking block 101, the straightening unit 102, and the tapered sealing head 103 are connected sequentially from top to bottom. Multiple milling grooves 104 and straightening ribs 105 are provided, and multiple milling grooves 104 and straightening ribs 105 are formed on the outside of the straightening unit 102 in a ring-shaped staggered distribution.

[0032] The inside of the straightening rib 105 is equipped with a ball bearing 2, which protrudes from the outside of the straightening rib 105 and rolls in contact with the rock cuttings bed to reduce the frictional resistance when the sand cover assembly 1 is lowered and rotated.

[0033] The straightening unit 102 is composed of a connecting cylinder 1021, a lower hollow cylinder 1023, an upper hollow cylinder 1024, and a hemispherical groove 1025;

[0034] The tapered threaded locking block 101 is fixed to the top of the connecting cylinder 1021, the lower hollow cylinder 1023 is fixed to the bottom of the connecting cylinder 1021, and the tapered sealing head 103 is fixed to the bottom of the lower hollow cylinder 1023.

[0035] The upper hollow cylinder 1024 is sleeved on the outside of the connecting cylinder 1021, and the milled groove 104 and the straightening rib 105 are formed on the outside of the lower hollow cylinder 1023 and the upper hollow cylinder 1024.

[0036] Hemispherical grooves 1025 are symmetrically opened on the upper surface of the lower hollow cylinder 1023 and the lower surface of the upper hollow cylinder 1024. When the upper hollow cylinder 1024 and the lower hollow cylinder 1023 are in contact with each other, the two hemispherical grooves 1025 form a spherical groove for the ball 2 to be limited and rolled.

[0037] Fastening component 3 includes an internal tapered threaded sleeve 301 and an anti-loosening triangular ratchet 302;

[0038] Multiple anti-loosening triangular ratchet teeth 302 are provided, and multiple anti-loosening triangular ratchet teeth 302 are fixed to the bottom of the inner tapered thread sleeve 301. Multiple circumferentially distributed triangular grooves 1027 are formed on the upper surface of the upper hollow cylinder 1024.

[0039] When the internal tapered threaded sleeve 301 is screwed into the tapered threaded locking block 101, it is engaged with the inner side of the triangular slot 1027 by the anti-loosening triangular ratchet 302 to realize the locking operation of the internal tapered threaded sleeve 301.

[0040] In this embodiment: When the sand shield assembly 1 is assembled with the feed section and the return cylinder, the fastening assembly 3 and the sand shield assembly 1 are successively sleeved on the feed section, so that the conical sealing head 103 contacts and engages with the top of the return cylinder, and then the inner conical threaded sleeve 301 is threadedly connected to the conical threaded locking block 101, so that the conical threaded locking block 101 shrinks and fits tightly against the outer wall of the section, thus realizing the installation and fixation of the sand shield assembly 1 and the section (it should be noted that the inner side of the inner conical threaded sleeve 301 has a conical structure, and as the inner conical threaded sleeve 301 and the conical threaded locking block 101 are tightened, the conical threaded locking block 101 can be squeezed and contracted).

[0041] By sealing the port of the return tube with the sand shield assembly 1, solid particles in the drilling fluid are prevented from entering the interior of the return tube during the lowering of the tailpipe hanger and the lifting and lowering of the movable tubing string when it encounters obstruction.

[0042] During this process, the ball bearing 2 rolls in contact with the cuttings bed, greatly reducing the upward thrust on the sand shield assembly 1. This ensures a tight fit between the sand shield and the return cylinder during the lowering of the tailpipe hanger, preventing frictional resistance from pushing the sand shield assembly 1 away from the return cylinder during lowering. At the same time, during the later horizontal rotation operation, the ball bearing 2 can also roll freely, maintaining a good state of low frictional resistance.

[0043] Please refer to Figure 3 for details. The outer side of the connecting cylinder 1021 is formed with a snap-fit ​​strip 1022, and the inner side of the upper hollow cylinder 1024 is formed with a snap-fit ​​groove 1026.

[0044] There are multiple hemispherical grooves 1025, snap-fit ​​strips 1022, and snap-fit ​​slots 1026. The multiple hemispherical grooves 1025 and snap-fit ​​strips 1022 are distributed alternately along the circumference, and the position of the snap-fit ​​slots 1026 corresponds one-to-one with the hemispherical grooves 1025.

[0045] In this embodiment: by interlocking the snap-fit ​​groove 1026 and the snap-fit ​​strip 1022, the automatic alignment and positioning of the hemispherical groove 1025 on the upper hollow cylinder 1024 and the lower hollow cylinder 1023 can be achieved, thereby facilitating the convenient installation of the ball bearing 2.

[0046] Please refer to Figures 1-3 for details. The tapered threaded locking block 101, connecting cylinder 1021, snap-fit ​​strip 1022, lower hollow cylinder 1023, hemispherical groove 1025, tapered sealing head 103, milled groove 104, and straightening rib 105 are integrally formed.

[0047] The upper hollow cylinder 1024, the snap-fit ​​groove 1026, the hemispherical groove 1025, the triangular snap-fit ​​groove 1027, the milled groove 104, and the straightening rib 105 are integrally formed;

[0048] The internal tapered thread sleeve 301 and the anti-loosening triangular ratchet tooth 302 are integrally formed.

[0049] In this embodiment: the combined straightening unit 2 structure facilitates the installation and assembly of the ball bearings 2;

[0050] During the tightening process of the inner tapered threaded sleeve 301 and the tapered threaded locking block 101, the anti-loosening triangular ratchet 302 will compress and shrink against the upper surface of the upper hollow cylinder 1024. When the anti-loosening triangular ratchet 302 is aligned with the triangular groove 1027, the anti-loosening triangular ratchet 302 will be inserted into the triangular groove 1027 under its own elastic force, thus preventing the inner tapered threaded sleeve 301 from rotating in the opposite direction and loosening.

[0051] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A protective device for a tailpipe hanger in an oil and gas well, comprising a sand-proof cover assembly (1) and a fastening assembly (3), characterized in that, The sand shield assembly (1) includes a conical threaded locking block (101), a straightening unit (102), a conical sealing head (103), a milling groove (104), and a straightening rib (105). The conical threaded locking block (101), the straightening unit (102), and the conical sealing head (103) are connected sequentially from top to bottom. Multiple milling grooves (104) and straightening ribs (105) are provided, and multiple milling grooves (104) and straightening ribs (105) are arranged in a staggered circumferential pattern on the outside of the straightening unit (102). A ball bearing (2) is rotatably installed inside the straightening rib (105). The ball bearing (2) protrudes from the outside of the straightening rib (105) and contacts the cuttings bed through the ball bearing (2). The movement is used to reduce the frictional resistance when the sand shield assembly (1) is lowered and rotated; the straightening unit (102) is composed of a connecting cylinder (1021), a lower hollow cylinder (1023), an upper hollow cylinder (1024), and a hemispherical groove (1025); the tapered threaded locking block (101) is fixed to the top of the connecting cylinder (1021), the lower hollow cylinder (1023) is fixed to the bottom of the connecting cylinder (1021), and the tapered sealing head (103) is fixed to the bottom of the lower hollow cylinder (1023); the upper hollow cylinder (1024) is sleeved on the outside of the connecting cylinder (1021), and the milled groove (104) and the straightening rib (105) are formed on the lower hollow cylinder (1023) and the upper hollow cylinder (1024). 024) Outer side; the hemispherical groove (1025) is symmetrically opened on the upper surface of the lower hollow cylinder (1023) and the lower surface of the upper hollow cylinder (1024). When the upper hollow cylinder (1024) and the lower hollow cylinder (1023) are in contact with each other, the two hemispherical grooves (1025) form a spherical groove for limiting the rolling of the ball (2); the outer side of the connecting cylinder (1021) is formed with a snap-fit ​​strip (1022), and the inner side of the upper hollow cylinder (1024) is formed with a snap-fit ​​groove (1026); the number of hemispherical grooves (1025), snap-fit ​​strips (1022), and snap-fit ​​grooves (1026) is the same and there are multiple of them. The multiple hemispherical grooves (1025) and snap-fit ​​strips (1022) are distributed alternately along the circumference. The position of the snap-fit ​​groove (1026) corresponds one-to-one with the hemispherical groove (1025); the fastening component (3) includes an inner conical threaded sleeve (301) and anti-loosening triangular ratchet (302); multiple anti-loosening triangular ratchets (302) are provided, and multiple anti-loosening triangular ratchets (302) are fixed to the bottom of the inner conical threaded sleeve (301); the upper surface of the upper hollow cylinder (1024) is formed with multiple circumferentially distributed triangular snap-fit ​​grooves (1027); when the inner conical threaded sleeve (301) is screwed into the conical threaded locking block (101), it is snapped into the inner side of the triangular snap-fit ​​groove (1027) by the anti-loosening triangular ratchet (302) to realize the locking operation of the inner conical threaded sleeve (301).

2. The protective device for the tailpipe suspension of an oil and gas well according to claim 1, characterized in that, The tapered threaded locking block (101), connecting cylinder (1021), snap-fit ​​strip (1022), lower hollow cylinder (1023), hemispherical groove (1025), tapered sealing head (103), milled groove (104), and straightening rib (105) are integrally formed; the upper hollow cylinder (1024), snap-fit ​​groove (1026), hemispherical groove (1025), triangular snap-fit ​​groove (1027), milled groove (104), and straightening rib (105) are integrally formed; the inner tapered threaded sleeve (301) and anti-loosening triangular ratchet (302) are integrally formed.

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