Ultra-high-temperature and ultra-high-pressure self-activation wellhead sealing device

Abstract

The utility model relates to the technical field of wellhead sealing devices, and discloses an ultra-high-temperature and ultra-high-pressure self-activation wellhead sealing device which comprises a four-way body, an oil pipe is arranged in the middle of the bottom end of the four-way body, a four-way cavity is formed in the four-way body, a hanger is arranged in the four-way cavity, and an oil pipe is arranged in the hanger. The four-way joint comprises a four-way joint body, an adjusting ring is arranged on the four-way joint body, a hanger is arranged on the four-way joint body, a threaded check ring is arranged on the outer side of the hanger in a sleeved mode, a sitting and hanging activation ring is arranged on the side edge of the threaded check ring, and a supporting ring is arranged on the top side of the sitting and hanging activation ring. The seat hanging activation ring, the supporting ring and the adjusting ring are arranged on the outer side of the hanger in a sleeving mode, so that the sealing device can be used between the hanger and the inner cavity of the four-way body, activation can be conducted through the dead weight of an underground tubular column, redundant steps are not needed, and the adjusting ring can control the compression amount of the sealing piece; and sealing elements are prevented from being damaged by overload while different pressure working conditions are adapted.

Description

Technical Field

[0001] The utility model relates to the technical field of wellhead sealing devices, in particular to an ultra-high temperature and ultra-high pressure self-activating wellhead sealing device. Background Art

[0002] With advancements in oil and gas field development technology, the areas available for exploration and production are becoming increasingly vast. In some areas, oil and gas wells must be drilled to depths exceeding 10,000 meters. As drilling progresses, downhole pressures and temperatures increase. This places higher demands on the sealing performance of wellhead equipment. Traditionally, rubber seals have generally performed adequately for wellhead pressures below 10,000 psi (70 MPa) and temperatures below 121°C. Conventional metal seals can also meet these requirements for pressures exceeding 10,000 psi (70 MPa), but below 20,000 psi (140 MPa), and temperatures below 180°C. However, when pressures exceed 20,000 psi (140 MPa), temperatures exceed 180°C, and even reach as high as 650°C, and these conditions are maintained for extended periods, conventional metal seals face challenges with creep and other factors, hindering their ability to maintain a consistent seal. This design was developed to address these sealing challenges at ultra-high pressures of 30,000 psi (210 MPa) and temperatures exceeding 650°C. Utility Model Content

[0003] To address the shortcomings of existing technologies, the present invention provides an ultra-high-temperature, ultra-high-pressure self-activating wellhead sealing device. This device addresses the problem that, in the past, rubber seals generally performed adequately when wellhead pressures were less than 10,000 psi (70 MPa) and temperatures were below 121°C. Conventional metal seals also met the requirements when pressures exceeded 10,000 psi (70 MPa), remained below 20,000 psi (140 MPa), and remained below 180°C. However, when pressures exceeded 20,000 psi (140 MPa), temperatures exceeded 180°C, and even reached as high as 650°C, and these conditions persisted for extended periods, conventional metal seals faced challenges in maintaining a consistent seal due to creep and other factors.

[0004] The utility model provides the following technical solution: an ultra-high temperature and ultra-high pressure self-activated wellhead sealing device, comprising a spool body, an oil pipe is provided in the middle of the bottom end of the spool body, a spool cavity is provided in the spool body, and a hanger is provided in the spool cavity;

[0005] The outer side of the hanger is sleeved with a threaded retaining ring, the side of the threaded retaining ring is provided with a sitting activation ring, the top side of the sitting activation ring is provided with a support ring, the support ring is sleeved on the outer side of the hanger, an outer graphite sealing ring is sleeved on the support ring, an adjustment ring is provided on the side of the outer graphite sealing ring, the outer side of the hanger is sleeved with an inner graphite sealing ring, a locking screw is provided between the threaded retaining ring and the hanger, and a four-way step is provided in the four-way cavity.

[0006] Preferred technical solution 1: A through hole is provided in the middle of the hanger, and the through hole is connected to the oil pipe.

[0007] Preferred technical solution 2: The bottom end of the threaded retaining ring is inclined.

[0008] Preferred technical solution three: the top of the support ring is convex.

[0009] Preferred technical solution four: the outer graphite sealing ring and the inner graphite sealing ring are arranged on both sides of the top protrusion of the support ring.

[0010] Preferred technical solution five: the adjustment ring is arranged between the outer graphite sealing ring and the inner graphite sealing ring.

[0011] This solution enables both sides of the adjustment ring to be limited by the outer graphite sealing ring and the inner graphite sealing ring.

[0012] Preferred technical solution six: the adjustment ring is fitted on the top of the support ring.

[0013] This solution can make the adjustment ring arranged on the top of the support ring more stable.

[0014] Preferred technical solution seven: The bottom end of the four-way step is inclined for easy installation.

[0015] This solution can make the four-way step more stably arranged in the four-way cavity.

[0016] Compared with the existing technology, the present invention provides an ultra-high temperature and ultra-high pressure self-activated wellhead sealing device, which has the following beneficial effects:

[0017] (1) The utility model provides a seating activation ring and a support ring on the four-way body, and an adjustment ring on the support ring. The seating activation ring, the support ring and the adjustment ring are sleeved on the outside of the hanger, so that the sealing device can be used between the hanger and the inner cavity of the four-way body, and can be activated by the deadweight of the downhole tubing, without the need for extra steps, easy to install, and saving drilling time. In addition, the sealing body of this structure is made of graphite material, which can meet the requirements of ultra-high temperature and ultra-high pressure, and can withstand ultra-high pressure 30,000psi (210MPa) and below, and ultra-high temperature 650℃ and below. The sealing structure of this structure can be automatically activated by the deadweight of the oil casing. This structure has an adjustment ring that can control the compression of the seal, adapting to different pressure conditions while preventing overload damage to the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structural cross section of the utility model;

[0019] Figure 2 For the utility model Figure 1 A magnified view of the structure of the middle adjustment ring;

[0020] Figure 3 For the utility model Figure 1 Enlarged view of the structure of the inner graphite sealing ring.

[0021] In the figure: 1. Cross body; 2. Oil pipe; 3. Hanger; 4. Threaded retaining ring; 5. Sitting activation ring; 6. Support ring; 7. Outer graphite sealing ring; 8. Adjusting ring; 9. Inner graphite sealing ring; 10. Locking screw; 11. Cross cavity; 12. Cross step. DETAILED DESCRIPTION

[0022] See also Figure 1-3 ,

[0023] Example 1: An ultra-high temperature and ultra-high pressure self-activated wellhead sealing device includes a spool body 1, an oil pipe 2 is provided in the middle of the bottom end of the spool body 1, a spool cavity 11 is provided in the spool body 1, and a hanger 3 is provided in the spool cavity 11;

[0024] The outer side of the hanger 3 is sleeved with a threaded retaining ring 4, the side of the threaded retaining ring 4 is provided with a sitting activation ring 5, the top side of the sitting activation ring 5 is provided with a support ring 6, the support ring 6 is sleeved on the outer side of the hanger 3, an outer graphite sealing ring 7 is sleeved on the support ring 6, the side of the outer graphite sealing ring 7 is provided with an adjusting ring 8, the outer side of the hanger 3 is sleeved with an inner graphite sealing ring 9, a locking screw 10 is provided between the threaded retaining ring 4 and the hanger 3, and a four-way step 12 is provided in the four-way cavity 11.

[0025] A through hole is provided in the middle of the hanger 3 , and the through hole is connected to the oil pipe 2 .

[0026] The bottom end of the threaded retaining ring 4 is inclined.

[0027] The top of the support ring 6 is convex.

[0028] The outer graphite sealing ring 7 and the inner graphite sealing ring 9 are arranged on both sides of the top protrusion of the support ring 6 .

[0029] Embodiment 2: The difference between this embodiment and embodiment 1 is that the adjustment ring 8 is arranged between the outer graphite sealing ring 7 and the inner graphite sealing ring 9.

[0030] Both sides of the adjustment ring 8 can be limited by the outer graphite sealing ring 7 and the inner graphite sealing ring 9.

[0031] Embodiment 3: The difference between this embodiment and embodiment 1 is that the adjustment ring 8 is fitted on the top of the support ring 6 .

[0032] This makes it more stable for the adjustment ring 8 to be arranged on the top of the support ring 6 .

[0033] Embodiment 4: The difference between this embodiment and embodiment 1 is that the bottom end of the four-way step 12 is inclined for easy installation.

[0034] This allows the four-way step 12 to be more stably arranged in the four-way cavity 11 .

[0035] In this embodiment, as the drilling depth increases, the pressure and temperature downhole will become higher and higher. This places higher demands on the sealing performance of the wellhead device. In the past, when the wellhead pressure was less than 10,000psi (70MPa) and the temperature was below 121°C, rubber seals were generally sufficient. When the pressure exceeds 10,000psi (70MPa) and is below 20,000psi140Mpa, and the temperature is below 180°C, ordinary metal seals can also meet the requirements. However, when the pressure exceeds 20,000psi140Mpa, the temperature exceeds 180°C, or even reaches 650°C, and is in this condition for a long time, ordinary metal seals will face challenges in sealing continuity due to creep and other reasons. This structure is proposed to solve the sealing problem under ultra-high pressure of 30,000psi210MPa and ultra-high temperature of 650°C.

[0036] In summary, in practice, after the tubing 2 is lowered to the specified wellhead depth, it is connected to the bottom of the hanger 3. The hanger 3, threaded retaining ring 4, seating activation ring 5, support ring 6, outer graphite seal 7, adjustment ring 8, inner graphite seal 9, and locking screw 10 are then lowered as a whole into the spool cavity 11 until the seating activation ring 5 contacts the spool step 12.

[0037] The weight of tubing 2 drives hanger 3 downward, compressing outer graphite seal 7, adjusting ring 8, and inner graphite seal 9. Simultaneously, seating activation ring 5, constrained by cross-step 12 and supported by support ring 6, prevents downward movement of outer graphite seal 7, adjusting ring 8, and inner graphite seal 9, respectively. Consequently, these seals are squeezed from above and below.

[0038] Therefore, after the graphite sealing ring 9 inside the outer graphite sealing ring 7 is compressed, it will expand in both the inner and outer diameter directions. At this time, the outer diameter of the outer graphite sealing ring 7 will be close to and squeeze the four-way cavity 11 to form a seal.

[0039] The inner diameter of the outer graphite seal ring 7 will be close to and squeeze the outer diameter of the support ring 6, forming a seal. The outer diameter of the inner graphite seal ring 9 will be close to and squeeze the inner diameter of the support ring 6, forming a seal. The inner diameter of the inner graphite seal ring 9 will be close to and squeeze the outer diameter of the hanger 3, forming a seal.

[0040] In this structure, the adjustment ring 8 is made of high-temperature resistant rubber or plastic. Depending on the pressure conditions, the adjustment ring 8 of different thicknesses can be replaced to adjust the compression degree of the outer graphite sealing ring 7 and the inner graphite sealing ring 9 to seal different pressures. At the same time, it can ensure that the outer graphite sealing ring 7 and the inner graphite sealing ring 9 will not be overloaded and cause sealing failure.

[0041] In this structure, the outer graphite sealing ring 7 and the inner graphite sealing ring 9 are made of graphite or a high-temperature resistant soft graphite material composed of graphite and other substances. They can withstand ultra-high pressure, ultra-high temperature, heavy load and other working conditions.

[0042] In this structure, the outer graphite sealing ring 7 and the inner graphite sealing ring 9 can be a plurality of stacked graphite rings, or a graphite ring with metal wrapping sheets at the upper and lower ends, or a graphite strip spirally wound in multiple layers.

[0043] In this structure, the weight of the oil pipe 2 is utilized to automatically activate the sealing effect of the inner graphite sealing ring 9 of the outer graphite sealing ring 7 through the hanger 3.

Claims

1. An ultra-high temperature and ultra-high pressure self-activated wellhead sealing device, characterized by: It comprises a four-way body (1), an oil pipe (2) is provided in the middle of the bottom end of the four-way body (1), a four-way cavity (11) is provided in the four-way body (1), and a hanger (3) is provided in the four-way cavity (11); The outer side of the hanger (3) is provided with a threaded retaining ring (4), the side of the threaded retaining ring (4) is provided with a sitting activation ring (5), the top side of the sitting activation ring (5) is provided with a support ring (6), the support ring (6) is sleeved on the outer side of the hanger (3), an outer graphite sealing ring (7) is sleeved on the support ring (6), an adjustment ring (8) is provided on the side of the outer graphite sealing ring (7), the outer side of the hanger (3) is sleeved with an inner graphite sealing ring (9), a locking screw (10) is provided between the threaded retaining ring (4) and the hanger (3), and a four-way step (12) is provided in the four-way cavity (11).

2. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 1, characterized in that: A through hole is provided in the middle of the hanger (3), and the through hole is connected to the oil pipe (2).

3. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 2, characterized in that: The bottom end of the threaded retaining ring (4) is inclined.

4. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 3, characterized in that: The top end of the support ring (6) is convex.

5. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 4, characterized in that: The outer graphite sealing ring (7) and the inner graphite sealing ring (9) are arranged on both sides of the top protrusion of the support ring (6).

6. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 5, characterized in that: The adjustment ring (8) is arranged between the outer graphite sealing ring (7) and the inner graphite sealing ring (9).

7. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 6, characterized in that: The adjustment ring (8) is fitted on the top end of the support ring (6).

8. The ultra-high temperature and ultra-high pressure self-activated wellhead sealing device according to claim 7, characterized in that: The bottom end of the four-way step (12) is inclined.

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