Wellhead inflatable multi-stage polished rod seal

Abstract

The utility model discloses a kind of wellhead inflatable multistage polished rod sealing devices, it includes polished rod, the polished rod is sequentially provided with blowout preventer mechanism, air bag sealing mechanism, packing sealing mechanism, ball head packing sealing mechanism and rubber sealing mechanism from top to bottom, the blowout preventer mechanism is equipped with trapezoidal oil receiving groove, the blowout preventer mechanism includes the blowout preventer cap being set around polished rod, blowout preventer cap is equipped with slide, the slide is mounted with blowout preventer ball and spring, the spring can be pressed to the blowout preventer ball to radial inside, the diameter of the blowout preventer ball is greater than the diameter of polished rod, the air bag sealing mechanism is equipped with air bag, and the air bag can be sealed to polished rod after being inflated, the packing sealing mechanism and ball head packing sealing mechanism are mounted with packing, and the packing can be sealed to polished rod, and the rubber sealing mechanism is mounted with rubber, and the rubber can be sealed to polished rod.The utility model has the advantages of avoiding the leakage and injection of petroleum, good sealing effect, easy installation, long service life and the like.

Description

Technical Field

[0001] This utility model relates to the field of oil production equipment technology, specifically a wellhead air-filled multi-stage polished rod sealing device. Background Technology

[0002] Currently, the polished rod seals and polished rods widely used in China for pumping units have simple structures and limited functions. During wellhead installation, various factors such as geological conditions, drilling, oilfield construction, installation, and differences in underground oil composition frequently cause problems like displacement, tilting, and corrosion of the polished rod. Existing technologies often use packing seals for the polished rod. However, during the up-and-down movement of the polished rod, displacement, tilting, and corrosion can easily cause misalignment between the seal, the polished rod, and the wellhead. This leads to uneven friction between the polished rod and the packing, resulting in excessive localized wear of the packing, affecting the sealing effect, and ultimately causing oil leaks and pollution. In severe cases, the polished rod may break, causing downtime and significant economic losses to oilfield production. Utility Model Content

[0003] The technical problem to be solved by this utility model is to provide a wellhead air-filled multi-stage polished rod sealing device that effectively seals the polished rod while preventing oil spraying after the polished rod breaks.

[0004] To solve the above-mentioned technical problems, this utility model includes a smooth rod, characterized by the following structural features: the smooth rod is provided with a blowout preventer, an airbag sealing mechanism, a packing sealing mechanism, a ball-head packing sealing mechanism, and a rubber sealing mechanism in sequence from top to bottom. A trapezoidal oil receiving groove is fixed to the blowout preventer. The blowout preventer includes a blowout preventer cap surrounding the smooth rod, and the blowout preventer cap has a slide. A blowout preventer ball and a spring are installed in the slide. A baffle is installed on one side of the spring. The spring can press the blowout preventer ball radially inward. The diameter of the blowout preventer ball is larger than the diameter of the smooth rod. The airbag sealing mechanism contains an airbag that can seal the smooth rod when inflated. Both the packing sealing mechanism and the ball-head packing sealing mechanism contain packing that can seal the smooth rod. The rubber sealing mechanism contains rubber that can seal the smooth rod.

[0005] With the above structure, the polished rod employs a three-stage seal, providing multi-level sealing to prevent oil leakage at the polished rod. A trapezoidal oil receiving groove is provided at the top of the polished rod to catch the oil carried out by the polished rod, preventing oil from re-entering the sealing mechanism and causing uneven wear on the packing. The three-stage seal is achieved through the packing sealing mechanism and the ball-head packing sealing mechanism, minimizing oil leakage from top to bottom. Simultaneously, the rubber seal is located below the packing seal, facilitating the installation of the upper sealing mechanism. An airbag seal is provided at the top. The airbag seal prevents oil carried by the polished rod from re-entering the packing, thus avoiding packing wear. A blowout preventer (BOP) is installed at the top. If the polished rod breaks and falls, a spring pushes the BOP ball towards the polished rod, pressing it against the BOP cap at the polished rod opening. The oil and gas pressure in the tubing forces the BOP ball to remain at the polished rod opening. The diameter of the BOP ball is larger than that of the polished rod to prevent it from falling out and thus preventing oil from spraying out. This provides both sealing and blowout prevention. The combination of the BOP and the three-stage sealing system ensures effective sealing and safe operation.

[0006] The airbag sealing mechanism includes an airbag cap surrounding the optical rod. The airbag cap has a chamber surrounding the optical rod, and an airbag is installed inside the chamber. The airbag has an inflation port that extends radially outward from the outer edge of the airbag toward the optical rod. An airbag box protecting the inflation port is provided on the outside of the airbag cap. Air is inflated into the airbag through the inflation port. After inflation, the airbag fills the chamber inside the airbag cap. After the airbag is filled, it compresses the optical rod, reducing the gap between the airbag and the optical rod, thereby sealing the optical rod.

[0007] The packing sealing mechanism includes a conical pressure cap surrounding a smooth rod, with an annular groove inside the conical pressure cap surrounding the smooth rod. A packing ring is installed in the annular groove to seal the smooth rod. A spacer is provided at the upper end of the packing ring to press it down. The bottom of the conical pressure cap is connected to a ball-head packing sealing mechanism. The packing ring surrounds the smooth rod, sealing it. The spacer presses the packing ring downwards, ensuring a tight seal and preventing displacement of the packing ring, thus guaranteeing the sealing performance of the packing seal.

[0008] The airbag cap and the conical cap are provided with a pipe wrench clamping groove that is tangent to the cylindrical outer edge of the conical cap. The pipe wrench clamping groove facilitates the clamping of the cap with a pipe wrench, which facilitates the tightening process of the airbag cap and ensures installation efficiency.

[0009] The ball head packing sealing mechanism includes a ball head fastening sleeve, within which a ball head assembly is installed. The ball head assembly includes a universal ball head and a sealing tube at the upper end of the universal ball head. The ball head assembly has a hollow structure surrounding the guide rod, and the hollow structure is filled with packing that wraps around the guide rod. The upper end of the universal ball head has a partition for pressing the packing. By setting the hollow structure, a packing seal is set in the hollow structure of the ball head packing sealing mechanism, further sealing the guide rod. The universal ball head can rotate flexibly within the ball head fastening sleeve, thereby adjusting the position of the universal ball head according to the inclination of the guide rod, and simultaneously adjusting the angle of the guide rod. Finally, the ball head fastening sleeve is tightened and fixed, which facilitates installation and improves efficiency.

[0010] The partition is provided with a conical groove, and two symmetrically arranged oil scraper blades are installed in the conical groove. After the two oil scraper blades are installed, they can surround the polished rod and scrape the crude oil off the polished rod. Together with the packing seal, they can achieve a better sealing effect.

[0011] The rubber sealing mechanism includes a push-pull rod fixing cap arranged around the smooth rod. The push-pull rod fixing cap has a cavity, and a rubber sheet surrounding and wrapping the smooth rod is placed inside the cavity. Two cylinders extending radially outward along the smooth rod are arranged symmetrically on the left and right sides of the push-pull rod fixing cap. A push rod that can move radially is installed inside the cylinder. A push plate that can move and squeeze the rubber sheet is provided on the radial inner side of the push rod. A semi-I-shaped handle switch that can adjust the position of the push plate is provided outside the cylinder. The rubber sheet is squeezed inward by the push rod, and the rubber sheet adheres to the smooth rod to form a rubber seal. After the rubber seal is formed, it can close the lower space, cut off the pressure transmission on the lower side, facilitate the installation of the upper sealing mechanism, and improve installation efficiency.

[0012] The packing is made of nitrile rubber or fluororubber, with a V-shaped structure and internal lubricating oil. Nitrile rubber and fluororubber have excellent corrosion resistance, which can effectively ensure sealing efficiency and improve service life.

[0013] The optical pole is equipped with an optical pole straightener located at the lower part of the optical pole. The optical pole straightener ensures the verticality and stability of the optical pole's up-and-down movement, preventing the optical pole from tilting during movement, which would lead to wear and tear on the optical pole, thereby ensuring its service life.

[0014] In summary, this utility model has the advantages of preventing oil leakage and spraying, good sealing effect, easy installation, and long service life. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the structure of this utility model after the smooth rod breaks;

[0017] Figure 3 This is a schematic diagram of the structure when the scraper blades are closed.

[0018] Figure 4 The front view after the two scraper blades are separated;

[0019] Figure 5 This is a top view after the two scraper blades have been separated. Detailed Implementation

[0020] like Figure 1 , 2 As shown, this utility model is a wellhead inflatable multi-stage polished rod sealing device, which includes a polished rod 1 and a multi-layer sealing mechanism surrounding the polished rod 1. From top to bottom, the polished rod 1 is equipped with a blowout preventer to prevent crude oil from gushing out after breakage, an airbag sealing mechanism to seal the polished rod 1, a packing sealing mechanism, a ball-head packing sealing mechanism, and a rubber sealing mechanism. The multi-layer sealing mechanism ensures the polished rod 1 remains sealed during movement. The airbag sealing mechanism at the upper end seals the upper end of the polished rod 1 by inflating the airbag 41, preventing impurities from adhering to the surface of the polished rod 1 and abrading the packing 53 during its up-and-down movement. The blowout preventer at the upper end prevents oil from gushing out and polluting the surrounding environment in the event of a breakage of the polished rod 1. Simultaneously, after sealing, the well pressure is adjusted to facilitate the retrieval of the polished rod 1, ensuring safety.

[0021] like Figure 1 , 2 As shown, the blowout preventer includes a blowout preventer cap 35 surrounding the guide rod 1. A slide 34 is provided inside the blowout preventer cap 35, and a blowout preventer ball 31 is installed within the slide 34. The diameter of the blowout preventer ball 31 is larger than the diameter of the guide rod 1. A spring 32 and a baffle are installed within the slide 34. A bolt is installed at the radially outer end of the slide 34, fixing one end of the spring 32. The other end of the spring 32 and the baffle press against the blowout preventer ball 31. The blowout preventer ball 31 is located radially inner to the spring 32, which is in a compressed state. When the guide rod 1 moves up and down reciprocally, the blowout preventer ball 31 presses against the guide rod 1 and the spring 32 and baffle. When the guide rod 1 breaks and falls, the pressure inside the tube exceeds atmospheric pressure, and the spring 32 pushes the blowout preventer ball 31 inward, causing the blowout preventer ball 31 to press against the hole in the guide rod 1 of the blowout preventer cap 35. The oil and gas pressure inside the pipe presses the blowout preventer ball 31 against the hole in the polished rod 1, preventing oil from splashing upwards. By stabilizing the pressure inside the pipe, environmental pollution caused by oil leakage is avoided, and oil waste is prevented. The outside of the blowout preventer cap 35 is provided with a pipe wrench clamping groove 5, which facilitates the gripping of the pipe wrench and the installation of the blowout preventer.

[0022] like Figure 1 , 2As shown, the blowout preventer is equipped with a trapezoidal oil receiving groove 2 for collecting oil. The trapezoidal oil receiving groove 2, the blowout preventer, and the airbag sealing mechanism are fixed together using hexagonal bolts. In this embodiment, the oil receiving groove is an upward-opening trapezoidal groove. The trapezoidal oil receiving groove 2 surrounds the polished rod 1, and the upper diameter of the trapezoidal oil receiving groove 2 is larger than the lower diameter, thus the sidewall of the trapezoidal oil receiving groove 2 is inclined, which serves to guide the flow to the bottom. This facilitates the collection of oil. When the polished rod 1 moves up and down, any crude oil carried out will be collected by the oil receiving groove. This prevents oil from flowing outwards, avoids oil pollution of the surrounding environment, facilitates oil collection, and also prevents impurities from being carried into the lower part, thus preventing friction between the polished rod 1 and the packing 53.

[0023] like Figure 1 , 2 As shown, the airbag sealing mechanism includes an airbag cap 44 surrounding the polished rod 1, with a chamber surrounding the polished rod 1 inside the airbag cap 44. An airbag box 43 is located on one side of the airbag cap 44. An airbag 41 is installed inside the chamber. The airbag 41 has an inflation port 42 extending radially outward from the polished rod 1 into the airbag box 43. An air pump is located inside the airbag box 43. Air is pumped into the airbag 41 within the chamber, causing it to expand. Once expanded, the airbag 41 fills the chamber and adheres to the polished rod 1 with its side facing it, thus sealing the polished rod 1. Located above the two-layer packing sealing mechanism, the airbag 41 more effectively prevents the carried-out oil from being re-carried into the sealing device by the polished rod 1, effectively protecting the lower packing 53 and reducing the frequency of packing 53 replacement.

[0024] like Figure 1-5 As shown, the packing sealing mechanism includes a conical pressure cap 54 surrounding the polished rod 1. The conical pressure cap 54 has an annular groove surrounding the polished rod 1, and a packing 53 is installed within the annular groove to seal the polished rod 1. A spacer 52 is provided at the upper end of the packing 53 to press it down. The bottom of the conical pressure cap 54 is connected to a ball-head packing sealing mechanism. The spacer 52 has a conical groove, within which two symmetrically arranged oil scraper blades 51 are installed. After installation, the two oil scraper blades 51 can encircle the polished rod 1, scraping away the crude oil on the polished rod 1. Combined with the packing 53, this achieves a better sealing effect. By wrapping the packing 53 around the polished rod 1, a sealing effect is achieved. The spacer 52 on the packing 53 effectively compresses the packing 53, ensuring its sealing performance.

[0025] like Figure 1-5As shown, the ball head packing sealing mechanism includes a ball head fastening sleeve 62, within which a ball head assembly 61 is installed. The ball head assembly 61 includes a universal ball head and a sealing tube located at the upper end of the universal ball head. A hollow structure is provided at the axis of the ball head assembly 61. During installation, the guide rod 1 passes through the hollow structure. The hollow structure is filled with packing 53 that wraps around the guide rod 1. The upper end of the universal ball head also has a partition 52 that presses against the packing 53. The upper end of the partition 52 also has a conical groove, within which two symmetrically arranged scraper blades 51 are installed. After installation, the two scraper blades 51 can encircle the guide rod 1, scraping away the crude oil on the guide rod 1. Combined with the packing 53, this achieves a better sealing effect. The universal ball head is an elliptical ball. The elliptical shape limits the rotation angle of the universal ball head, preventing large-angle skew of the ball head assembly 61, facilitating installation, and improving installation efficiency. The ball head assembly 61 and the ball head fastening sleeve 62 are provided with a force-applying rod 55. By gripping the force-applying rod 55, the ball head assembly 61 and the ball head fastening sleeve 62 can be rotated and installed.

[0026] like Figure 1 , 2 As shown, packing 53 is made of either fluororubber or nitrile rubber. Fluororubber packing 53 has good high-temperature resistance and corrosion resistance, which can improve its service life. Nitrile rubber has excellent oil resistance and heat resistance, which can effectively prevent oil molecules from penetrating, ensuring sealing efficiency and service life.

[0027] like Figure 1 , 2 As shown, the rubber sealing mechanism includes a push-pull rod fixing cap surrounding the smooth rod 1. The upper end of the push-pull rod fixing cap is threadedly connected to the ball head fastening sleeve 62, which, in conjunction with the ball head fastening sleeve 62, restricts the position of the universal ball head, facilitating its installation. The push-pull rod fixing cap has an internal cavity, within which a rubber sheet 71 surrounds and wraps around the smooth rod 1. The push-pull rod fixing cap has two cylinders 75 extending radially outward along the smooth rod 1, symmetrically arranged. A push rod is located inside each cylinder 75, and a push plate 73, capable of moving and pressing the rubber sheet 71, is located on the radially inner side of the push rod. A semi-inverted handle switch 72, capable of adjusting the position of the push plate 73, is located outside each cylinder 75. The push rod is threadedly connected to the outer end face of the cylinder 75. The semi-inverted handle switch 72 rotates the push rod, thereby changing the position of the push block. The push block presses the rubber sheet 71 towards the smooth rod 1, effectively sealing the smooth rod 1.

[0028] like Figure 1 , 2As shown, when the packing 53 needs to be replaced, rotating the semi-straight handle switch 72 drives the pusher block 62 to move, thereby tightly fitting the rubber 71 and the polished rod 1 together. After fitting, the rubber 71 seals the space under the polished rod 1, cutting off the upward pressure transmission from the wellhead. Then, the packing 53 inside the universal ball head can be easily replaced, improving the replacement efficiency of the packing 53 and ensuring the sealing quality. At the same time, the angle of the universal ball head can be adjusted according to the position and angle of the polished rod 1. After the angle of the polished rod 1 is consistent with the angle of the sealing device, the sealing device achieves step-by-step sealing. The ball head fastening sleeve 6254 can be easily adjusted, reducing wear and improving efficiency.

[0029] like Figure 1 , 2 As shown, a clamp 81 is provided at the lower end of the rubber sealing mechanism, and a pressure reducer 82 is installed inside the clamp 81. The pressure reducer relieves the pressure inside the well. A polished rod centralizer 9 is installed on the polished rod below the rubber sealing mechanism. The polished rod centralizer 9 is fitted onto the polished rod 1, ensuring the verticality and stability of the polished rod 1 during its up-and-down movement, preventing the polished rod 1 from tilting during movement, which would lead to wear of the polished rod 1 and thus ensure its service life. A polished rod coupling 10 is installed at the bottom end of the polished rod 1 for connecting the polished rod 1 and the sucker rod to achieve power transmission.

[0030] like Figure 1 , 2 As shown, the surface of the optical rod 1 is coated with a stainless steel protective layer. The surface finish of the optical rod 1 has a thickness of 0.263 μm or more. This stainless steel protective layer protects the surface of the optical rod 1, providing corrosion resistance and extending its service life. Furthermore, the 0.263 μm thickness ensures smooth vertical movement of the optical rod 1, thus guaranteeing work efficiency.

Claims

1. A wellhead pneumatic multi-stage polished rod sealing device, comprising a polished rod (1), characterized in that, The polished rod (1) is provided with a blowout preventer, an airbag sealing mechanism, a packing sealing mechanism, a ball head packing sealing mechanism and a rubber sealing mechanism from top to bottom. The blowout preventer is provided with a trapezoidal oil receiving groove (2). The blowout preventer includes a blowout preventer cap (35) arranged around the polished rod (1). The blowout preventer cap (35) is provided with a slide (34). A blowout preventer ball (31) and a spring (32) are installed in the slide (34). A baffle is installed on one side of the spring (32). The spring (32) can press the blowout preventer ball (31) radially inward. The diameter of the blowout preventer ball (31) is larger than the diameter of the polished rod (1). The airbag sealing mechanism is provided with an airbag (41) that can seal the polished rod (1) after inflation. The packing sealing mechanism and the ball head packing sealing mechanism are both provided with packing (53) that can seal the polished rod (1). The rubber sealing mechanism is provided with rubber (71) that can seal the polished rod (1).

2. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 1, characterized in that: The airbag sealing mechanism includes an airbag cap (44) located around the light rod (1). The airbag cap (44) has a chamber surrounding the light rod (1), and an airbag (41) is installed in the chamber. The airbag (41) has an inflation port (42) that extends radially outward from the outer edge of the airbag (41) toward the light rod (1). An airbag box (43) protecting the inflation port (42) is provided on the outside of the airbag cap (44).

3. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 2, characterized in that: The airbag cap (44) is provided with a pipe wrench groove (5) that is tangent to the outer edge of the circle.

4. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 1, characterized in that: The packing sealing mechanism includes a conical pressure cap (54) arranged around the smooth rod (1), an annular groove arranged around the smooth rod (1) is provided in the conical pressure cap (54), and a packing (53) for sealing around the smooth rod (1) is installed in the annular groove. A partition (52) for pressing the packing (53) is provided at the upper end of the packing (53), and the bottom of the conical pressure cap (54) is connected to the ball head packing sealing mechanism.

5. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 1, characterized in that: The ball head packing sealing mechanism includes a ball head fastening sleeve (62), and a ball head assembly (61) is installed inside the ball head fastening sleeve (62). The ball head assembly (61) includes a universal ball head and a sealing tube at the upper end of the universal ball head. The ball head assembly (61) is provided with a hollow structure surrounding the light rod (1). The hollow structure is filled with packing (53) that wraps around the light rod (1). The upper end of the universal ball head is provided with a partition (52) that presses the packing (53).

6. The wellhead pneumatic multi-stage polished rod sealing device as described in any one of claims 4 or 5, characterized in that: The partition (52) is provided with a conical groove, and two symmetrically arranged oil scraper blades (51) are installed in the conical groove. After the two oil scraper blades (51) are installed, they can surround the light rod (1).

7. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 1, characterized in that: The rubber sealing mechanism includes a push-pull rod fixing cap arranged around the light rod (1). The push-pull rod fixing cap has a cavity inside, and a rubber sheet (71) surrounding and wrapping the light rod (1) is arranged inside the cavity. Two cylinders (75) are arranged outside the push-pull rod fixing cap, extending radially outward along the light rod (1). The two cylinders (75) are arranged symmetrically on the left and right. A push rod that can move radially is installed inside the cylinder (75). A push plate (73) that can move and squeeze the rubber sheet (71) is provided on the radial inner side of the push rod. A semi-inverted handle switch (72) that can adjust the position of the push plate (73) is provided outside the cylinder (75).

8. The wellhead pneumatic multi-stage polished rod sealing device as described in any one of claims 4 or 5, characterized in that: The packing (53) is made of nitrile rubber or fluororubber, has a V-shaped structure, and contains lubricating oil.

9. The wellhead pneumatic multi-stage polished rod sealing device as described in claim 1, characterized in that: The optical rod (1) is provided with an optical rod straightener (9), which is located at the lower part of the optical rod (1).

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