Pressure balance type eccentric wellhead
By introducing a hydraulic oil balance system into the eccentric wellhead, the flange damage and leakage problems caused by pressure imbalance in the prior art are solved, and the stability and sealing of the wellhead equipment are achieved.
Patent Information
- Application Number
- CN202510606124.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-12
- Publication Date
- 2025-06-17
AI Technical Summary
The existing eccentric wellheads are likely to cause unilateral pressure overload when used, resulting in pressure imbalance, which in turn causes local deformation or rupture at the flange connection, causing leakage.
The pressure balanced eccentric wellhead design is adopted, including the wellhead device body, lower flange, upper flange, annular compensation chamber, oil pipe side and rotating mechanism. The pressure of the wellhead device is balanced by the flow of hydraulic oil between the annular compensation chamber and the oil pipe side to prevent flange damage.
It effectively prevents damage and leakage in the flange, ensures the stability and sealing of the wellhead device, and extends the service life of the equipment.
Smart Images
Figure CN120159331A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of eccentric wellheads, and more specifically to a pressure-balanced eccentric wellhead. Background Art
[0002] An eccentric wellhead is a special wellhead device designed specifically to adapt to complex wellbore trajectories or extreme working conditions. Its core features are the use of an asymmetric structure design and a dynamic pressure balance mechanism to address the limitations of traditional symmetric wellheads in terms of sealing performance, stability, and installation centering.
[0003] The patent with the publication number CN205025406 discloses an eccentric wellhead device. This eccentric wellhead device includes a wellhead rotation device and a hydraulic support structure. The hydraulic support structure includes a base plate disposed on the wellhead rotation system and a support rod located on the base plate, and a test hole is provided in the base plate; a drive head is disposed on the upper end surface of the hydraulic support structure, and the drive head and the hydraulic support structure are arranged in the vertical direction; a polished rod, the drive head penetrates into the polished rod, and the polished rod passes through the center of the hydraulic support structure. Without increasing the height of the test wellhead and without changing the size of the test instrument (the maximum length is 80 cm and the diameter is 28 mm), this patent solves the problems of difficult entry of the test instrument into the well, entanglement after entering the well, and wellhead leakage by changing the wellhead structure form and sealing method. However, when this device is in use, it is prone to causing unilateral pressure overload on the eccentric wellhead, resulting in pressure imbalance, local deformation or rupture at the flange connection, and thus leakage. Therefore, a pressure-balanced eccentric wellhead is proposed to solve the above-mentioned problems. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide a pressure-balanced eccentric wellhead for the deficiencies in the above-mentioned prior art.
[0005] To solve the above technical problems, the technical solution adopted by the present invention is: a pressure-balanced eccentric wellhead, including the wellhead device body. A lower flange is fixedly connected to the top of the wellhead device body, and an upper flange is installed on the top of the lower flange. From the outside to the inside of the upper flange, an annulus side, an annular compensation chamber, and a tubing side are respectively provided. The tubing side communicates with the inner wall of the upper flange, the annular compensation chamber communicates with the tubing side, and the annulus side communicates with the annular compensation chamber. A rotating mechanism is arranged inside the annular compensation chamber; the rotating mechanism includes a motor, a gear, a rotating ring, teeth, a stirring plate, a support plate, and an arc plate. The motor is fixedly connected to the top of the upper flange, the gear is fixedly connected to the output end of the motor, the support plate is fixedly connected to the inner wall of the annular compensation chamber, the rotating ring is rotatably connected to the surface of the support plate, the teeth are fixedly connected to the circumferential surface of the rotating ring, the stirring plates are fixedly connected to the top and bottom of the rotating ring, the arc plate is fixedly connected to the inner wall of the rotating ring, and a check valve is installed on the inner wall of the top of the upper flange; the circumferential surface of the gear meshes with the surface of the teeth. Hydraulic oil is provided inside the annular compensation chamber. The check valve is used to add hydraulic oil to the inside of the annular compensation chamber, and the hydraulic oil is high-viscosity hydraulic oil; a flow guiding mechanism is arranged on the inner wall of the tubing side, and a protection mechanism is arranged on the inner wall of the upper flange. When the pressure in the wellhead device rises, the oil will enter the tubing side, and then enter the annular compensation chamber and push the hydraulic oil in the annular compensation chamber to the annulus side, reducing the pressure impact on the sealing surface of the tubing side, thereby achieving pressure balance and preventing damage to the flange. The rotation of the stirring plate can relatively improve the fluidity of the hydraulic oil inside the annular compensation chamber, making it convenient to be pushed by the high-pressure fluid entering the inside of the tubing side and move to the annulus side, improving the speed of pressure balance.
[0006] Preferably, the flow guiding mechanism includes a moving rod, a sphere, and a baffle. The moving rod is slidably connected to the inner wall of the upper flange through a spring. The sphere is fixedly connected to one end of the moving rod away from the oil pipe side. The baffle is fixedly connected to the circumferential surface of the moving rod away from the annular compensation cavity. The surface of the baffle contacts the inner wall of the oil pipe side. The surface of the sphere contacts the inner wall of the rotating ring. The sphere is located on the movement track of the arc-shaped plate. The flow guiding mechanism further includes a mounting ring, a guiding plate, a limiting ring, and an inclined groove. The limiting ring is rotatably connected to the inner wall of the oil pipe side. The guiding plate is fixedly connected to the surface of the limiting ring. The mounting ring is fixedly connected to one side of the guiding plate away from the limiting ring. The inclined groove is formed on the circumferential surface of the mounting ring. The number of moving rods is set to twelve. The twelve moving rods are circularly arrayed and equidistantly distributed on the inner wall of the upper flange. The number of arc-shaped plates is set to six. The six arc-shaped plates are circularly arrayed and equidistantly distributed on the inner wall of the rotating ring. The baffle can intermittently open and close the communication hole between the annular compensation cavity and the oil pipe side, thereby reducing the leakage amount of hydraulic oil, and making the communication hole only open intermittently when pressure balance is required, shortening the exposure time of hydraulic oil to high pressure difference, suppressing the formation of turbulence. At the same time, the guiding plate can push the high-pressure fluid entering the inner part of the oil pipe side to be evenly distributed. After passing through the communication hole between the annular compensation cavity and the oil pipe side, the high-pressure fluid inside the oil pipe side can evenly enter the annular compensation cavity for pressure balance.
[0007] Preferably, the protection mechanism includes a filter plate, a rotating ring, a scraping strip, an arc-shaped groove, a sliding rod, a guiding rod, and a roller. The filter plate is fixedly installed on the inner wall of the upper flange. The rotating ring is rotatably connected to the bottom of the filter plate. The scraping strip is fixedly connected to the inner wall of the rotating ring. The arc-shaped groove is formed on the bottom of the rotating ring. The sliding rod is slidably connected to the inner wall of the upper flange through a spring. The guiding rod is fixedly connected to the circumferential surface of the sliding rod away from the oil pipe side. The roller is rotatably connected to the inner wall of the sliding rod close to the annular compensation cavity. The protection mechanism further includes a dredging rod. The dredging rod is fixedly connected to the circumferential surface of the sliding rod and is located in the oil pipe side. The circumferential surface of the guiding rod contacts the inner wall of the arc-shaped groove. The top of the scraping strip contacts the bottom of the filter plate. The circumferential surface of the roller contacts the surface of the guiding plate. The circumferential surface of the rotating ring is rotatably connected to the inner wall of the upper flange. The filter plate can filter the fluid in the wellhead device and capture impurities. The scraping strip can push the impurities at the bottom of the filter plate to prevent the impurities from accumulating in one place and affecting the subsequent passage of fluid. At the same time, when the wellhead device stops working, the rotation of the scraping strip can scrape and remove the impurities filtered at the bottom of the filter plate. At the same time, when the sliding rod moves, it drives the dredging rod to move. The dredging rod can reciprocally move in the communication hole between the oil pipe side and the inner part of the wellhead device oil pipe to dredge and prevent blockage.
[0008] The present invention adopts the above technical solutions and can bring the following beneficial effects: 1. In this pressure-balanced eccentric wellhead, when the pressure in the wellhead device rises, the oil will enter the tubing side and then enter the annular compensation chamber, pushing the hydraulic oil in the annular compensation chamber to the annulus side, reducing the pressure impact on the sealing surface of the tubing side, thus balancing the pressure and preventing damage at the flange. The rotation of the stirring plate can relatively improve the fluidity of the hydraulic oil inside the annular compensation chamber, making it convenient to be pushed by the high-pressure fluid entering the tubing side and move to the annulus side, thereby increasing the speed of pressure balance.
[0009] 2. In this pressure-balanced eccentric wellhead, the baffle can intermittently open and close the communication hole between the annular compensation chamber and the tubing side, thereby reducing the leakage of hydraulic oil and making the communication hole open only intermittently when pressure balance is required, shortening the time for the hydraulic oil to be exposed to the high pressure difference and suppressing the formation of turbulence. The guide plate can push the high-pressure fluid entering the tubing side to be evenly distributed, so that after passing through the communication hole between the annular compensation chamber and the tubing side, the high-pressure fluid inside the tubing side can evenly enter the annular compensation chamber for pressure balance.
[0010] 3. In this pressure-balanced eccentric wellhead, the filter plate can filter the fluid in the wellhead device and capture impurities, while the scraping bar can push the impurities at the bottom of the filter plate to prevent the impurities from accumulating in one place and affecting the subsequent passage of the fluid. At the same time, when the wellhead device stops working, the rotation of the scraping bar can scrape off and remove the impurities filtered at the bottom of the filter plate. Meanwhile, when the sliding rod moves, it drives the dredging rod to move. The dredging rod can reciprocate in the communication hole between the tubing side and the inside of the wellhead tubing to dredge and prevent blockage. Description of the Drawings
[0011] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a half-sectional view of the upper flange structure of the present invention; Figure 3 It is a schematic diagram of the rotating ring structure of the present invention; Figure 4 It is a half-sectional view of the rotating ring structure of the present invention; Figure 5 It is a schematic diagram of the mounting ring structure of the present invention; Figure 6 It is a schematic diagram of the filter plate structure of the present invention; Figure 7 It is a schematic diagram of the rotating ring structure of the present invention; Figure 8 It is of the present invention Figure 7 Enlarged view of the structure at A in the present invention.
[0012] In the figure: 1. Wellhead device body; 2. Lower flange; 3. Upper flange; 31. Tubing side; 32. Annular compensation chamber; 33. Annulus side; 4. Rotating mechanism; 41. Motor; 42. Gear; 43. Rotating ring; 44. Teeth; 45. Stirring plate; 46. Support plate; 47. Arc plate; 5. Flow guiding mechanism; 51. Moving rod; 52. Sphere; 53. Baffle; 54. Mounting ring; 55. Guide plate; 56. Limit ring; 57. Inclined groove; 6. Protection mechanism; 61. Filter plate; 62. Rotating ring; 63. Scraping bar; 64. Arc groove; 65. Slide bar; 66. Guide bar; 67. Roller; 68. Unblocking rod. Detailed implementation mode
[0013] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.
[0014] Please refer to Figures 1 - 8, an embodiment of the present invention is: a pressure-balanced eccentric wellhead, including a wellhead device body 1. A lower flange 2 is fixedly connected to the top of the wellhead device body 1. An upper flange 3 is installed on the top of the lower flange 2. From the outside to the inside of the upper flange 3, an annulus side 33, an annular compensation chamber 32, and a tubing side 31 are respectively provided. The tubing side 31 communicates with the inner wall of the upper flange 3. The annular compensation chamber 32 and the tubing side 31 communicate with each other. The annulus side 33 and the annular compensation chamber 32 communicate with each other. A rotating mechanism 4 is arranged inside the annular compensation chamber 32; the rotating mechanism 4 includes a motor 41, a gear 42, a rotating ring 43, teeth 44, a stirring plate 45, a support plate 46, and an arc plate 47. The motor 41 is fixedly connected to the top of the upper flange 3. The gear 42 is fixedly connected to the output end of the motor 41. The support plate 46 is fixedly connected to the inner wall of the annular compensation chamber 32. The rotating ring 43 is rotatably connected to the surface of the support plate 46. The teeth 44 are fixedly connected to the circumferential surface of the rotating ring 43. The stirring plate 45 is fixedly connected to the top and bottom of the rotating ring 43. The arc plate 47 is fixedly connected to the inner wall of the rotating ring 43. A one-way valve is installed on the inner wall of the top of the upper flange 3. When the pressure in the wellhead device rises, the oil fluid will enter the tubing side 31 and then enter the annular compensation chamber 32, pushing the hydraulic oil in the annular compensation chamber 32 to the annulus side 33, reducing the pressure impact on the sealing surface of the tubing side 31, thereby balancing the pressure and preventing damage to the flange; the circumferential surface of the gear 42 meshes with the surface of the teeth 44. Hydraulic oil is arranged inside the annular compensation chamber 32. The one-way valve is used to add hydraulic oil to the inside of the annular compensation chamber 32. The hydraulic oil is high-viscosity hydraulic oil; a flow guiding mechanism 5 is arranged on the inner wall of the tubing side 31, and a protection mechanism 6 is arranged on the inner wall of the upper flange 3. When the pressure difference between the pressure sensors in the wellhead device and the annular compensation chamber 32 is greater than the set threshold, an electrical signal will be sent to the motor 41. The motor 41 receiving the electrical signal will start and drive the gear 42 to rotate. The gear 42 drives the rotating ring 43 to rotate through the teeth 44. The rotating ring 43 drives the stirring plate 45 to rotate. Since the high-viscosity hydraulic oil is arranged inside the annular compensation chamber 32, the rotation of the stirring plate 45 at this time can relatively improve the fluidity of the hydraulic oil inside the annular compensation chamber 32, facilitating it to be pushed by the high-pressure fluid entering the tubing side 31 and moving to the annulus side 33, improving the speed of pressure balance.
[0015] Working principle: When the pressure in the wellhead device rises, the oil will enter the tubing side 31 and then enter the annular compensation chamber 32, pushing the hydraulic oil in the annular compensation chamber 32 to the annulus side 33, reducing the pressure impact on the sealing surface of the tubing side 31, thereby balancing the pressure and preventing damage at the flange. When the pressure difference between the wellhead device and the pressure sensor in the annular compensation chamber 32 is greater than the set threshold, an electrical signal will be sent to the motor 41. The motor 41 that receives the electrical signal will start and drive the gear 42 to rotate. The gear 42 drives the rotating ring 43 to rotate through the teeth 44, and the rotating ring 43 drives the stirring plate 45 to rotate. Since the high-viscosity hydraulic oil is set inside the annular compensation chamber 32, the rotation of the stirring plate 45 at this time can relatively improve the fluidity of the hydraulic oil inside the annular compensation chamber 32, facilitating it to be pushed by the high-pressure fluid entering the tubing side 31 and moving to the annulus side 33, improving the speed of pressure balance.
[0016] Please refer to Figures 1 - 8, on the basis of the above embodiments, in another embodiment of the present invention, the flow guiding mechanism 5 includes a moving rod 51, a sphere 52 and a baffle 53. The moving rod 51 is slidably connected to the inner wall of the upper flange 3 through a spring. The sphere 52 is fixedly connected to one end of the moving rod 51 away from the oil pipe side 31. The baffle 53 is fixedly connected to the circumferential surface of the moving rod 51 away from one end of the annular compensation chamber 32. The surface of the baffle 53 contacts the inner wall of the oil pipe side 31, and the surface of the sphere 52 contacts the inner wall of the rotating ring 43. The sphere 52 is located on the movement track of the arc plate 47. When the rotating ring 43 rotates, it will drive the arc plate 47 to rotate. The arc plate 47 pushes the sphere 52 to rotate through the arc surface. However, the sphere 52 is fixed on the moving rod 51, and the moving rod 51 can only slide in the inner wall of the upper flange 3. Therefore, the arc plate 47 can only drive the sphere 52 to move. The sphere 52 drives the moving rod 51 to move, and the moving rod 51 will compress the spring. When the arc plate 47 passes over the sphere 52, the compressed spring will drive the moving rod 51 to reset. At this time, the moving rod 51 will reciprocate. The moving rod 51 drives the baffle 53 to reciprocate. The baffle 53 can intermittently open and close the communication hole between the annular compensation chamber 32 and the oil pipe side 31, thereby reducing the leakage amount of hydraulic oil, and making the communication hole only open intermittently when the pressure needs to be balanced, shortening the time for hydraulic oil to be exposed to high pressure difference, and suppressing the formation of turbulence; the flow guiding mechanism 5 further includes a mounting ring 54, a guiding plate 55, a limiting ring 56 and an inclined groove 57. The limiting ring 56 is rotatably connected to the inner wall of the oil pipe side 31. The guiding plate 55 is fixedly connected to the surface of the limiting ring 56. The mounting ring 54 is fixedly connected to one side of the guiding plate 55 away from the limiting ring 56. The inclined groove 57 is opened on the circumferential surface of the mounting ring 54; the number of the moving rods 51 is set to twelve. The twelve moving rods 51 are circularly arranged and equidistantly distributed on the inner wall of the upper flange 3. The number of the arc plates 47 is set to six, and the six arc plates 47 are circularly arranged and equidistantly distributed on the inner wall of the rotating ring 43. The number of the arc plates 47 is set to six, and the number of the moving rods 51 is set to twelve. When six of the arc plates 47 rotate, they will simultaneously push six of the twelve moving rods 51 that are spaced apart from each other to move. At this time, after the six moving rods 51 that are spaced apart from each other move, they will push the inclined groove 57 and the mounting ring 54 to rotate through the inclined surface. At this time, the inclined surface of the inclined groove 57 will move to the remaining six moving rods 51 that have not moved. At this time, when the arc plate 47 continues to rotate, it will drive the remaining six moving rods 51 to move, and will again push the mounting ring 54 to rotate through the inclined surface on the inclined groove 57. And at this time, the previous six moving rods 51 will reciprocate under the action of the spring. In this way, the rotation of the mounting ring 54 can be realized. When the mounting ring 54 rotates, it can drive the guiding plate 55 to rotate. The guiding plate 55 can push the high-pressure fluid entering the inner part of the oil pipe side 31 to be evenly distributed, so that after the communication hole between the annular compensation chamber 32 and the oil pipe side 31, the high-pressure fluid inside the oil pipe side 31 can evenly enter the annular compensation chamber 32 and balance the pressure.
[0017] The protection mechanism 6 includes a filter plate 61, a rotating ring 62, a scraping bar 63, an arc-shaped groove 64, a sliding rod 65, a guiding rod 66 and a roller 67. The filter plate 61 is fixedly installed on the inner wall of the upper flange 3. The rotating ring 62 is rotatably connected to the bottom of the filter plate 61. The scraping bar 63 is fixedly connected to the inner wall of the rotating ring 62. The arc-shaped groove 64 is formed in the bottom of the rotating ring 62. The sliding rod 65 is slidably connected to the inner wall of the upper flange 3 through a spring. The guiding rod 66 is fixedly connected to the circumferential surface of one end of the sliding rod 65 away from the oil pipe side 31. The roller 67 is rotatably connected to the inner wall of one end of the sliding rod 65 close to the annular compensation cavity 32. The filter plate 61 can filter the fluid in the wellhead device and capture impurities. When the guiding plate 55 rotates, it will push the roller 67 to move through its own inclined surface. The roller 67 drives the sliding rod 65 to move. When the sliding rod 65 moves, it will compress the spring. When the guiding plate 55 passes over the roller 67, the spring will drive the sliding rod 65 to reset, thereby realizing the reciprocating movement of the sliding rod 65. And the sliding rod 65 will drive the guiding rod 66 to reciprocate. When the guiding rod 66 moves, it drives the rotating ring 62 to rotate back and forth reciprocally through the arc-shaped groove 64. The rotating ring 62 drives the scraping bar 63 to rotate. The scraping bar 63 can push the impurities at the bottom of the filter plate 61 to prevent the impurities from accumulating in one place and affecting the subsequent passage of the fluid. The protection mechanism 6 further includes a dredging rod 68. The dredging rod 68 is fixedly connected to the circumferential surface of the sliding rod 65, and the dredging rod 68 is located in the oil pipe side 31. The circumferential surface of the guiding rod 66 is in contact with the inner wall of the arc-shaped groove 64. The top of the scraping bar 63 is in contact with the bottom of the filter plate 61. The circumferential surface of the roller 67 is in contact with the surface of the guiding plate 55. The circumferential surface of the rotating ring 62 is rotatably connected to the inner wall of the upper flange 3. When the wellhead device stops working, the rotation of the scraping bar 63 can scrape and remove the impurities filtered at the bottom of the filter plate 61. At the same time, when the sliding rod 65 moves, it drives the dredging rod 68 to move. The dredging rod 68 can reciprocate in the communication hole between the oil pipe side 31 and the inside of the wellhead device oil pipe to dredge and prevent blockage.
[0018] Working principle: When the rotating ring 43 rotates, it drives the arc-shaped plate 47 to rotate. The arc-shaped plate 47 pushes the sphere 52 to rotate through the arc surface. However, the sphere 52 is fixed on the moving rod 51, and the moving rod 51 can only slide on the inner wall of the upper flange 3. Therefore, the arc-shaped plate 47 can only drive the sphere 52 to move, and the sphere 52 drives the moving rod 51 to move. The moving rod 51 compresses the spring. When the arc-shaped plate 47 passes over the sphere 52, the compressed spring drives the moving rod 51 to reset. At this time, the moving rod 51 reciprocates. The moving rod 51 drives the baffle 53 to reciprocate. The baffle 53 can intermittently open and close the communication hole between the annular compensation chamber 32 and the oil pipe side 31, thereby reducing the leakage of hydraulic oil, and making the communication hole only open intermittently when pressure balance is required, shortening the time for hydraulic oil to be exposed to high pressure difference, suppressing the formation of turbulence. At the same time, the number of arc-shaped plates 47 is set to six, and the number of moving rods 51 is set to twelve. When six of the arc-shaped plates 47 rotate, they will simultaneously push six of the twelve moving rods 51 that are spaced apart to move. At this time, after the six spaced-apart moving rods 51 move, they will push the inclined groove 57 and the mounting ring 54 to rotate through the inclined surface. At this time, the inclined surface of the inclined groove 57 will move to the remaining six non-moving moving rods 51. At this time, when the arc-shaped plate 47 continues to rotate, it will drive the remaining six moving rods 51 to move, and again push the mounting ring 54 to rotate through the inclined surface on the inclined groove 57. At this time, the previous six moving rods 51 will reciprocate under the action of the spring. In this way, the rotation of the mounting ring 54 can be realized. When the mounting ring 54 rotates, it can drive the guide plate 55 to rotate. The guide plate 55 can push the high-pressure fluid entering the inside of the oil pipe side 31 to be evenly distributed. After the communication hole between the annular compensation chamber 32 and the oil pipe side 31, the high-pressure fluid inside the oil pipe side 31 can evenly enter the annular compensation chamber 32 for pressure balance; The filter plate 61 can filter the fluid in the wellhead device and capture impurities. When the guide plate 55 rotates, it pushes the roller 67 to move through its own inclined surface. The roller 67 drives the sliding rod 65 to move. When the sliding rod 65 moves, it compresses the spring. When the guide plate 55 passes over the roller 67, the spring drives the sliding rod 65 to reset, thereby realizing the reciprocating movement of the sliding rod 65. The sliding rod 65 drives the guide rod 66 to reciprocate. When the guide rod 66 moves, it drives the rotating ring 62 to rotate reciprocally in both forward and reverse directions through the arc-shaped groove 64. The rotating ring 62 drives the scraping strip 63 to rotate. The scraping strip 63 can push the impurities at the bottom of the filter plate 61 to prevent the impurities from accumulating in one place and affecting the subsequent passage of the fluid. At the same time, when the wellhead device stops working, the rotation of the scraping strip 63 can scrape off and remove the impurities filtered at the bottom of the filter plate 61. At the same time, when the sliding rod 65 moves, it drives the dredging rod 68 to move. The dredging rod 68 can reciprocate in the communication hole between the oil pipe side 31 and the inside of the wellhead device oil pipe to dredge and prevent blockage.
[0019] The present invention provides a pressure-balanced eccentric wellhead. There are many methods and ways to specifically implement this technical solution. The above description is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention. Each component not clearly defined in this embodiment can be implemented by existing technologies.
Claims
1. A pressure-balanced eccentric wellhead, comprising a wellhead device body (1), characterized in that: A lower flange (2) is fixedly connected to the top of the wellhead device body (1); an upper flange (3) is installed on the top of the lower flange (2); an annular side (33), an annular compensation cavity (32) and an oil pipe side (31) are respectively provided inside the upper flange (3) from the outside to the inside; the oil pipe side (31) is communicated with the inner wall of the upper flange (3); the annular compensation cavity (32) is communicated with the oil pipe side (31); the annular side (33) is communicated with the annular compensation cavity (32); and a rotating mechanism (4) is provided inside the annular compensation cavity (32); The rotating mechanism (4) comprises a motor (41), a gear (42), a rotating ring (43), teeth (44), a stirring plate (45), a support plate (46) and an arc plate (47); the motor (41) is fixedly connected to the top of the upper flange (3); the gear (42) is fixedly connected to the output end of the motor (41); the support plate (46) is fixedly connected to the inner wall of the annular compensation cavity (32); the rotating ring (43) is rotatably connected to the surface of the support plate (46); the teeth (44) are fixedly connected to the circumferential surface of the rotating ring (43); the stirring plate (45) is fixedly connected to the top and bottom of the rotating ring (43); the arc plate (47) is fixedly connected to the inner wall of the rotating ring (43); and a one-way valve is installed on the inner wall of the top of the upper flange (3).
2. The pressure-balanced eccentric wellhead according to claim 1, characterized in that: The circumferential surface of the gear (42) meshes with the surface of the tooth (44); hydraulic oil is provided inside the annular compensation chamber (32); the one-way valve is used to add hydraulic oil to the inside of the annular compensation chamber (32); the hydraulic oil is a high-viscosity hydraulic oil; and the support plate (46) is used to support the rotating ring (43).
3. The pressure-balanced eccentric wellhead according to claim 2, characterized in that: The inner wall of the oil pipe side (31) is provided with a flow guide mechanism (5), and the inner wall of the upper flange (3) is provided with a protection mechanism (6).
4. The pressure-balanced eccentric wellhead according to claim 3, characterized in that: The flow guide mechanism (5) comprises a moving rod (51), a sphere (52) and a baffle (53); the moving rod (51) is slidably connected to the inner wall of the upper flange (3) via a spring; the sphere (52) is fixedly connected to an end of the moving rod (51) away from the oil pipe side (31); and the baffle (53) is fixedly connected to a circumferential surface of an end of the moving rod (51) away from the annular compensation chamber (32).
5. The pressure-balanced eccentric wellhead according to claim 4, characterized in that: The surface of the baffle (53) contacts the inner wall of the oil pipe side (31), the surface of the sphere (52) contacts the inner wall of the rotating ring (43), and the sphere (52) is located on the movement trajectory of the arc plate (47).
6. The pressure-balanced eccentric wellhead according to claim 5, characterized in that: The flow guide mechanism (5) further comprises a mounting ring (54), a guide plate (55), a limiting ring (56) and an inclined groove (57); the limiting ring (56) is rotatably connected to the inner wall of the oil pipe side (31); the guide plate (55) is fixedly connected to the surface of the limiting ring (56); the mounting ring (54) is fixedly connected to a side of the guide plate (55) away from the limiting ring (56); and the inclined groove (57) is provided on the circumferential surface of the mounting ring (54).
7. The pressure-balanced eccentric wellhead according to claim 6, characterized in that: The number of the movable rods (51) is twelve, and the twelve movable rods (51) are arranged in a circular array and are evenly distributed on the inner wall of the upper flange (3); the number of the arc plates (47) is six, and the six arc plates (47) are arranged in a circular array and are evenly distributed on the inner wall of the rotating ring (43).
8. The pressure-balanced eccentric wellhead according to claim 7, characterized in that: The protection mechanism (6) comprises a filter plate (61), a rotating ring (62), a scraper bar (63), an arc groove (64), a slide bar (65), a guide rod (66) and a roller (67); the filter plate (61) is fixedly mounted on the inner wall of the upper flange (3); the rotating ring (62) is rotatably connected to the bottom of the filter plate (61); the scraper bar (63) is fixedly connected to the inner wall of the rotating ring (62); the arc groove (64) is provided at the bottom of the rotating ring (62); the slide bar (65) is slidably connected to the inner wall of the upper flange (3) via a spring; the guide rod (66) is fixedly connected to the circumferential surface of one end of the slide bar (65) away from the oil pipe side (31); and the roller (67) is rotatably connected to the inner wall of one end of the slide bar (65) close to the annular compensation chamber (32).
9. The pressure-balanced eccentric wellhead according to claim 8, characterized in that: The protection mechanism (6) further comprises a dredging rod (68), wherein the dredging rod (68) is fixedly connected to the circumferential surface of the sliding rod (65), and the dredging rod (68) is located in the oil pipe side (31).
10. The pressure-balanced eccentric wellhead according to claim 9, characterized in that: The circumferential surface of the guide rod (66) contacts the inner wall of the arc groove (64), the top of the scraper strip (63) contacts the bottom of the filter plate (61), the circumferential surface of the roller (67) contacts the surface of the guide plate (55), and the circumferential surface of the rotating ring (62) is rotatably connected to the inner wall of the upper flange (3).