Sealing structure for steam injection test wellhead

Abstract

The utility model discloses a sealing structure for a steam injection test wellhead, which belongs to the technical field of oil field engineering and comprises a well casing, a polish rod penetrates through the middle of the well casing, a bracket is fixedly connected to the inner wall of the well casing, the bracket is annular, a plurality of insertion holes are formed in the edge of the bracket, and a sealing component is clamped at the wellhead at the top of the well casing. According to the sealing structure for the steam injection test wellhead, the air bag sealing ring expands and expands outwards, meanwhile, the multiple sealing rings are driven to be tightly attached to the inner wall of the well casing, when steam is injected into the well casing, the internal pressure of the well casing is increased, the supporting assembly is jacked upwards, and the supporting assembly moves upwards and extrudes the air bag sealing ring again; the air bag sealing ring drives the sealing ring to be more tightly attached to the inner wall of the well casing, so that the sealing effect is better in the process that the pressure in the well casing is gradually increased, the traditional mode of adopting a rubber sealing piece or a metal spiral wound gasket is abandoned for sealing work, and steam leakage is prevented from influencing the testing stability.

Description

Technical Field

[0001] This utility model belongs to the field of oilfield engineering technology, specifically a sealing structure for steam injection testing wellheads. Background Technology

[0002] In the field of oil extraction, steam injection thermal recovery technology is an important means to improve the recovery rate of heavy oil and extra-heavy oil. By injecting high-temperature and high-pressure steam into the oil layer, the viscosity of crude oil can be reduced and its fluidity improved, thereby achieving efficient crude oil extraction. During the steam injection operation, the test wellhead, as the key hub connecting the surface steam injection equipment and the underground oil layer, directly affects the steam injection effect, operational safety, and environmental protection.

[0003] Traditional steam injection test wellhead sealing structures mostly use rubber seals or metal spiral wound gaskets. Under the long-term effects of high temperature, high pressure, and corrosive chemicals in steam, rubber seals are prone to aging, deformation, and cracking, leading to seal failure. Metal spiral wound gaskets will experience stress relaxation due to thermal expansion and contraction. At the same time, solid particles carried by steam will also damage the gasket surface, thereby reducing sealing performance and causing steam leakage. Summary of the Invention

[0004] To overcome the above-mentioned defects, this utility model provides a sealing structure for steam injection test wellheads, which solves the problems of rubber seals being prone to aging, deformation and cracking under long-term effects of high temperature, high pressure and corrosive chemicals in steam, leading to sealing failure, and metal spiral wound gaskets being prone to stress relaxation due to thermal expansion and contraction, and the solid particles carried by steam also damaging the gasket surface, thus reducing sealing performance.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a sealing structure for a steam injection test wellhead, comprising a well pipe, a smooth rod penetrating through the middle of the well pipe, a bracket fixedly connected to the inner wall of the well pipe, the bracket being annular in design with several insertion holes at its edge, a sealing assembly snapped into the wellhead at the top of the well pipe, a plugging assembly fixedly attached to the top of the sealing assembly, the smooth rod penetrating and fixedly embedded in the sealing assembly and the plugging assembly, the outer wall of the sealing assembly fitting against the inner wall of the well pipe, a support assembly fixedly connected to the bottom of the sealing assembly, the bottom end of the support assembly sliding through and sliding within the insertion hole on the bracket, the sealing assembly including a limiting frame, the limiting frame being T-shaped with an airbag sealing ring fitted at its bottom, the outer wall of the airbag sealing ring having several sealing rings fitting against the inner wall of the well pipe, and the bottom of the airbag sealing ring being fixed to the top of the support assembly.

[0006] As a further embodiment of this utility model: the support component includes a fixing ring, and a plurality of insertion rods corresponding to the insertion holes are fixed at the bottom of the fixing ring. The insertion rods slide through the insertion holes, and the bottom of the fixing ring overlaps with the bracket.

[0007] As a further embodiment of this utility model: the light rod is disposed through the middle of the fixed ring, four telescopic rods are fixed at equal intervals on the edge of the fixed ring, a retaining ring is fixed at the top of the four telescopic rods, a spring is sleeved on the telescopic rod, and the top of the retaining ring is fixed to the bottom of the airbag sealing ring.

[0008] As a further embodiment of this utility model: the sealing assembly includes a pressure cap, with handles fixedly connected to both sides of the pressure cap, and a support bearing snapped into the middle of the pressure cap, the support bearing being fixed to the outer wall of the smooth rod.

[0009] As a further embodiment of this utility model: four locking blocks are fixedly connected at equal intervals at the bottom edge of the pressure cap, and the locking blocks are T-shaped.

[0010] As a further embodiment of this utility model: four slides are equally spaced at the edge of the top of the well pipe, and a concave hole is provided in the middle of the slide. The locking block passes through the concave hole and is locked in the slide.

[0011] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0012] This sealing structure for steam injection testing wellheads uses a plugging assembly to insert the sealing component into the well casing. The support component at the bottom of the sealing component contacts the bracket. As the limiting bracket in the sealing component continuously presses down on the airbag sealing ring, the airbag sealing ring is compressed by the support component and the limiting bracket, causing it to expand and extend outwards. Simultaneously, this causes multiple sealing rings to fit tightly against the inner wall of the well casing. This expansion and compression improves the sealing effect. When steam is injected into the well casing, the internal pressure increases, pushing up the support component. The support component moves upwards and further compresses the airbag sealing ring, making the sealing rings fit even more tightly against the inner wall of the well casing. Therefore, as the internal pressure of the well casing gradually increases, the sealing effect improves. This method abandons the traditional method of using rubber seals or metal spiral wound gaskets for sealing, preventing steam leakage from affecting test stability.

[0013] This sealing structure for steam injection test wellheads, when the support assembly is placed inside the well casing, allows the insert rod at the bottom of the support assembly to engage with the insertion hole on the bracket, thus limiting the position of the fixing ring and the upper sealing assembly. This prevents the sealing assembly from freely deflecting and affecting sealing stability. When the pressure inside the well casing increases, it pushes the fixing ring upwards, which in turn squeezes the upper telescopic rod and spring. The spring force provides reverse support to the fixing ring, thus providing a buffering effect on the sealing assembly, reducing the force exerted on the sealing structure, and improving sealing stability.

[0014] This sealing structure for steam injection test wellheads works by limiting the sealing assembly. The pressure cap is placed on top of the well casing, and the bottom locking block engages in a recessed hole. Then, by holding the two handles and rotating the pressure cap, the outer ring of the support bearing rotates. The support bearing limits the pressure cap, improving the stability of the locking block's deflection. During this process, the locking block penetrates the recessed hole and slides in the slide. Because the T-shaped locking block's bottom diameter is larger than the slide's width and it is located below the slide, it effectively limits the pressure cap vertically, preventing the sealing and support assemblies from detaching from the well casing under pressure. To remove the sealing assembly, hold the two handles and rotate the pressure cap, moving multiple locking blocks directly below the recessed hole. Lifting the handles causes the pressure cap to dislodge the locking blocks from the recessed hole, thus improving ease of operation. Attached Figure Description

[0015] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0016] Figure 2 This is a schematic diagram of the cross-section of the well casing of this utility model;

[0017] Figure 3 This is a schematic diagram of the sealing component structure of this utility model;

[0018] Figure 4 This is a partial three-dimensional structural diagram of the present invention;

[0019] Figure 5 This is a front view structural diagram of the sealing assembly of this utility model;

[0020] Figure 6 This is a schematic diagram showing the separation of the sealing component and the plugging component of this utility model;

[0021] In the diagram: 1. Well casing; 2. Polished rod; 3. Bracket; 4. Insertion hole; 5. Sealing assembly; 501. Limiting bracket; 502. Airbag sealing ring; 503. Sealing ring; 6. Support assembly; 601. Fixing ring; 602. Insert rod; 603. Telescopic rod; 604. Spring; 605. Retaining ring; 7. Sealing assembly; 701. Pressure cap; 702. Support bearing; 703. Clamping block; 704. Handle; 8. Slide; 9. Concave hole. Detailed Implementation

[0022] The technical solution of this patent will be further described in detail below with reference to specific embodiments.

[0023] like Figure 1-6 As shown, this utility model provides a technical solution: a sealing structure for a steam injection test wellhead, including a well pipe 1, a smooth rod 2 passing through the middle of the well pipe 1, a bracket 3 fixedly connected to the inner wall of the well pipe 1, the bracket 3 being a ring design with several insertion holes 4 at its edge, a sealing component 5 snapped into the wellhead at the top of the well pipe 1, a plugging component 7 fixedly fixed to the top of the sealing component 5, the smooth rod 2 passing through and fixed in the sealing component 5 and the plugging component 7, the plugging component 7 including a pressure cap 701, handles 704 fixedly connected to both sides of the pressure cap 701, a support bearing 702 snapped into the middle of the pressure cap 701, the support bearing 702 being fixed to the outer wall of the smooth rod 2, by holding the two handles 704 and rotating the pressure cap 701, causing the pressure cap 701 to drive the outer ring of the support bearing 702 to rotate, the support bearing 702 limiting the pressure cap 701 and improving its rotational stability;

[0024] Four locking blocks 703 are fixedly connected at equal intervals at the bottom edge of the pressure cap 701. The locking blocks 703 are T-shaped. Four slides 8 are equally spaced at the top edge of the well pipe 1. A recess 9 is provided in the middle of the slide 8. The locking blocks 703 pass through the recess 9 and are locked in the slide 8. The locking blocks 703 pass through the recess 9 and slide in the slide 8. Since the bottom diameter of the T-shaped locking blocks 703 is larger than the width of the slide 8 and is located below the slide 8, it can limit the pressure cap 701 in the vertical direction and prevent the sealing component 5 and the support component 6 from being dislodged from the well pipe 1 after being pressed.

[0025] The outer wall of the sealing component 5 is in contact with the inner wall of the well pipe 1. The bottom of the sealing component 5 is fixedly connected to the support component 6. The bottom end of the support component 6 slides through the insertion hole 4 on the bracket 3. The support component 6 includes a fixing ring 601. Several insertion rods 602 corresponding to the insertion hole 4 are fixed at the bottom of the fixing ring 601. The insertion rods 602 slide through the insertion hole 4. The bottom of the fixing ring 601 overlaps with the bracket 3. The insertion rods 602 can be inserted into the insertion hole 4 on the bracket 3, which plays a role in limiting the fixing ring 601 and the sealing component 5 above, preventing the sealing component 5 from freely deflecting and affecting the sealing stability.

[0026] The sealing assembly 5 includes a limiting frame 501, which is T-shaped and has an airbag sealing ring 502 fitted at the bottom. The outer wall of the airbag sealing ring 502 is provided with several sealing rings 503 and fits against the inner wall of the well pipe 1. The bottom of the airbag sealing ring 502 is fixed to the top of the support assembly 6. The airbag sealing ring 502 can be squeezed by the support assembly 6 and the limiting frame 501, causing the airbag sealing ring 502 to expand and extend outward. At the same time, it drives the multiple sealing rings 503 to fit tightly against the inner wall of the well pipe 1. The sealing effect is improved by the expansion and compression.

[0027] The smooth rod 2 is installed through the middle of the fixed ring 601. Four telescopic rods 603 are fixed at equal intervals on the edge of the fixed ring 601. The top of the four telescopic rods 603 is fixed with a retaining ring 605. The telescopic rods 603 are sleeved with springs 604. The top of the retaining ring 605 is fixed to the bottom of the airbag sealing ring 502. When the internal pressure of the well pipe 1 increases, it pushes the fixed ring 601 upward. The fixed ring 601 then squeezes the upper telescopic rods 603 and springs 604. The elastic force of the springs 604 provides reverse support to the fixed ring 601, which plays a supporting and buffering role for the sealing assembly 5 and weakens the force generated on the sealing structure.

[0028] The working principle of this utility model is as follows:

[0029] When sealing the wellhead at the top of the well pipe 1, hold the two handles 704 and place the pressure cap 701 on the top of the well pipe 1, so that the support component 6 at the bottom of the sealing component 5 contacts the bracket 3. The insertion rod 602 at the bottom of the support component 6 can be inserted into the insertion hole 4 on the bracket 3, which serves to limit the fixed ring 601 and the upper sealing component 5, preventing the sealing component 5 from freely deflecting and affecting the sealing stability. As the limiting bracket 501 in the sealing component 5 continues to press down on the airbag sealing ring 502, the airbag sealing ring 502 can be squeezed by the support component 6 and the limiting bracket 501, causing the airbag sealing ring 502 to expand and expand outward, while driving multiple sealing rings 503 to fit tightly against the inner wall of the well pipe 1. The sealing effect is improved by expanding and squeezing. When steam is injected into the well pipe 1, it increases the internal pressure and pushes the support component 6 upward. The support component 6 moves upward and squeezes the airbag sealing ring 502 again, causing the airbag sealing ring 502 to drive the sealing rings 503 to fit tightly against the well. The inner wall of pipe 1 fits more tightly. When the internal pressure of pipe 1 increases, it pushes the fixing ring 601 upwards. The fixing ring 601 then squeezes the upper telescopic rod 603 and spring 604. The elastic force of spring 604 provides reverse support to the fixing ring 601, which plays a supporting and buffering role for the sealing assembly 5. Secondly, the locking block 703 at the bottom of the pressure cap 701 is engaged in the recessed hole 9. By holding the two handles 704 and rotating the pressure cap 701, the locking block 703 penetrates the recessed hole 9 and slides in the slide rail 8. The bottom diameter of the T-shaped locking block 703 is larger than the width of the slide 8 and is located below the slide 8. It can limit the vertical position of the pressure cap 701 and prevent the sealing component 5 and the support component 6 from detaching from the well pipe 1 after being pressed. When removing the plugging component 7, hold the two handles 704 and rotate the pressure cap 701 so that the pressure cap 701 moves multiple locking blocks 703 directly below the concave hole 9. Lift the handles 704 to make the pressure cap 701 move the locking blocks 703 out of the concave hole 9 and remove it.

[0030] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0031] The preferred embodiments of this patent have been described in detail above. However, this patent is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this patent.

Claims

1. A sealing structure for a steam injection test wellhead, comprising a well pipe (1), characterized in that: A smooth rod (2) is inserted through the middle of the well pipe (1). A bracket (3) is fixedly connected to the inner wall of the well pipe (1). The bracket (3) is annular and has several insertion holes (4) at its edge. A sealing assembly (5) is snapped into the wellhead at the top of the well pipe (1). A plugging assembly (7) is fixed to the top of the sealing assembly (5). The smooth rod (2) is inserted and fixed in the sealing assembly (5) and the plugging assembly (7). The outer wall of the sealing assembly (5) is in contact with the inner wall of the well pipe (1). The bottom of component (5) is fixedly connected to a support component (6). The bottom end of the support component (6) slides through the insertion hole (4) on the bracket (3). The sealing component (5) includes a limiting frame (501). The limiting frame (501) is T-shaped and has an airbag sealing ring (502) sleeved at the bottom. The outer wall of the airbag sealing ring (502) is provided with several sealing rings (503) and fits against the inner wall of the well pipe (1). The bottom of the airbag sealing ring (502) is fixed to the top of the support component (6).

2. The sealing structure for a steam injection test wellhead according to claim 1, characterized in that: The support assembly (6) includes a fixing ring (601), and a plurality of insertion rods (602) corresponding to the insertion holes (4) are fixed at the bottom of the fixing ring (601). The insertion rods (602) slide through the insertion holes (4), and the bottom of the fixing ring (601) overlaps with the bracket (3).

3. A sealing structure for a steam injection test wellhead according to claim 2, characterized in that: The light rod (2) is installed through the middle of the fixed ring (601). Four telescopic rods (603) are fixed at equal intervals on the edge of the fixed ring (601). A retaining ring (605) is fixed at the top of the four telescopic rods (603). A spring (604) is sleeved on the telescopic rod (603). The top of the retaining ring (605) is fixed to the bottom of the airbag sealing ring (502).

4. A sealing structure for a steam injection test wellhead according to claim 1, characterized in that: The sealing assembly (7) includes a pressure cap (701), with handles (704) fixedly connected to both sides of the pressure cap (701), and a support bearing (702) snapped into the middle of the pressure cap (701), which is fixed to the outer wall of the smooth rod (2).

5. A sealing structure for a steam injection test wellhead according to claim 4, characterized in that: Four locking blocks (703) are fixedly connected at equal intervals at the bottom edge of the cap (701), and the locking blocks (703) are T-shaped.

6. A sealing structure for a steam injection test wellhead according to claim 5, characterized in that: Four slides (8) are equally spaced at the top edge of the well pipe (1). A recess (9) is provided in the middle of the slide (8). The locking block (703) passes through the recess (9) and is locked in the slide (8).

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