Thermal recovery wellhead with composite thermal insulation structure

Abstract

The invention relates to the technical field of thermal recovery well mouths, and discloses a thermal recovery well mouth with a composite heat preservation structure, which comprises a well mouth body and an arc-shaped plate, the surface of the well mouth body is fixedly communicated with a well mouth pipeline, the inner wall of the arc-shaped plate is in threaded connection with a two-way screw rod, and one side of the arc-shaped plate is in contact with the well mouth body. An elastic telescopic rod is fixedly connected to the other side of the arc-shaped plate, a supporting block is fixedly connected to the end, away from the arc-shaped plate, of the elastic telescopic rod, an arc-shaped strip is rotationally connected to the top of the supporting block, a pressing block is rotationally connected to the top of the arc-shaped strip, and a supporting rod is fixedly connected to the top of the arc-shaped plate; the supporting area of the supporting block on the well mouth body can be increased, then the pressure intensity borne by the ground is reduced, foundation sinking or collapse caused by too high pressure intensity is avoided, meanwhile, vibration generated when the well mouth device operates is transmitted to the ground, and then the vibration resistance of the device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of thermal recovery wellheads, in particular to a thermal recovery wellhead with a composite thermal insulation structure. Background Art

[0002] Thermal recovery wellhead refers to the wellhead equipment of oil and gas wells used for thermal recovery operations. It is mainly used in the process of oil extraction, especially for some high-viscosity, heavy oil or oil reservoirs with high water content. Thermal recovery technology is usually used to promote the fluidity of oil and facilitate oil extraction.

[0003] The patent with announcement number CN207315289U provides a double-tube thermal recovery wellhead device. The double-tube thermal recovery wellhead device includes a double-tube shell and a sealer assembly. The double-tube shell includes: a first longitudinal channel, the first longitudinal channel cooperates with the light rod sealer; a second longitudinal channel, separated from the first longitudinal channel; a first transverse channel, connected to the first longitudinal channel, and a first gate valve is provided on the first transverse channel; wherein the sealer assembly is arranged at the opening of the second longitudinal channel, and the sealer assembly includes a sealer body and a flow passage arranged on the sealer body and connected to the second longitudinal channel; the double-tube shell also includes a valve port connected to the second longitudinal channel, and a second gate valve for controlling the opening and closing of the second longitudinal channel is provided at the valve port. The patent double-tube thermal recovery wellhead device does not need to disassemble the packing box during pressure operation, and can be directly used for pressure lifting and lowering of continuous tubing operations, but when the device is installed on the ground, the contact area with the ground is small, which leads to a large pressure on the ground, and the risk of settlement is prone to occur, and the seismic effect is low, so a thermal recovery wellhead with a composite insulation structure 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 thermal recovery wellhead with a composite insulation structure in view of the deficiencies in the above-mentioned prior art.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a thermal recovery wellhead with a composite insulation structure, including a wellhead body and an arc-shaped plate, the surface of the wellhead body is fixedly connected with a wellhead pipeline, the inner wall of the arc-shaped plate is threadedly connected with a bidirectional screw, one side of the arc-shaped plate is in contact with the wellhead body, the other side of the arc-shaped plate is fixedly connected with an elastic telescopic rod, one end of the elastic telescopic rod away from the arc-shaped plate is fixedly connected with a support block, the top of the support block is rotatably connected with an arc strip, the top of the arc strip is rotatably connected with a pressure block, and the top of the arc-shaped plate is fixedly connected with a support Rod, the top of the support rod is fixedly connected with a support plate, the inner wall of the arc plate is provided with a pressure relief mechanism for auxiliary drainage and pressure relief when the flange connection leaks, and the inner wall of the wellhead body is provided with a dredging mechanism for dredging accumulated impurities and reducing the internal pressure of the wellhead body; the number of the arc plates is two, and the two arc plates are symmetrically distributed on the left and right sides of the wellhead body, the surface of the wellhead body is sleeved with an insulation sleeve, and the insulation sleeve consists of an outer layer and an inner layer; the inner layer is aerogel plus alkali-free glass fiber, the outer layer is fireproof cloth or silicone coating, and the insulation sleeve is made of Fix it with Velcro, buckles or metal buckles; the circumferential surface of the wellhead pipe contacts the top of the pressure block, and the side of the support plate away from the support rod contacts the surface of the wellhead body. The support block is placed on the ground, and then the wellhead body is correctly installed. After the wellhead is installed, the bidirectional screw is rotated by the tool, and the bidirectional screw drives the two arc plates to gather together. The arc plates will clamp the flange connection under the wellhead body. At the same time, the two arc plates drive the two support rods to gather together, and the two support rods drive the two support plates to gather together. The support plates will further clamp the wellhead body and align the entire wellhead body through the support blocks. The wellhead device provides support to improve the overall stability of the device. At the same time, when the wellhead pipeline is installed together with the wellhead device, the wellhead pipeline will press on the pressure block and push the pressure block downward. The pressure block pushes the arc bar to move, and the arc bar pushes the support block to move to the side away from the arc plate, so that the two support blocks move in opposite directions and increase the distance between them, thereby increasing the support area of ​​the support block for the wellhead body, thereby reducing the pressure on the ground, avoiding sinking or collapse of the foundation due to excessive pressure, and at the same time transmitting the vibration of the wellhead device during operation to the ground, thereby improving the vibration resistance of the device.

[0006] Preferably, the pressure relief mechanism includes a moving rod, a transmission plate, a vent and a baffle, the moving rod is slidably connected to the inner wall of the wellhead body, the transmission plate is fixedly connected to the circumferential surface of the moving rod, the vent is opened inside the moving rod, and the baffle is slidably connected to the inner wall of the arc plate; the pressure relief mechanism also includes an air groove, an extension plate, a clamping groove and a threaded tube, the air groove is opened on a side of the arc plate close to the wellhead body, the extension plate is fixedly connected to the surface of the arc plate, the clamping groove is opened on the surface of the extension plate, and the threaded tube is fixedly connected to the side of the arc plate away from the wellhead body; a sensor is provided on the inner wall of the threaded tube, the clamping groove is connected to the air groove, and the circumferential surface of the moving rod is slidably connected to the inner wall of the arc plate; the flange connection of the wellhead body is flush with the clamping groove and the air groove, the side of the moving rod away from the transmission plate is in contact with the baffle, the extension plate is in contact with the wellhead body, and the flange at the bottom of the wellhead bears greater pressure because it is directly When the wellhead device is subjected to the original pressure downhole and is used for a long time, the bottom flange connection is prone to leakage if it is not repaired in time. The leaked oil or saturated steam will seep out through the flange connection. At this time, the leaked oil or saturated steam will enter the arc plate through the guide of the card slot and the gas slot, and the leaked high-pressure gas or liquid will push the baffle plate up. After the baffle plate moves up, it will no longer block the moving rod. At this time, the transmission plate inside the wellhead device will be pushed by the pressure and drive the moving rod to penetrate the arc plate, so that the moving rod extends into the threaded pipe, and the vent in the moving rod will connect the wellhead with the threaded pipe, so that the gas and liquid in the wellhead can be discharged directly, and the pressure is reduced to prevent the flange connection from continuing to leak, thereby polluting the surrounding environment. The threaded pipe is connected to a collection pipe for collecting the gas or liquid discharged due to pressure relief. At the same time, the sensor inside the threaded pipe detects liquid or gas and issues an alarm to remind workers that the wellhead is leaking.

[0007] Preferably, the dredging mechanism includes a guide plate, a guide groove, a guide column, a guide rod, a filter plate and an arc-shaped push plate, wherein the guide plate is fixedly connected to the top of the baffle plate, the guide groove is arranged on the surface of the guide plate, the guide column is slidably connected to the inner wall of the wellhead body, the guide rod is fixedly connected to the circumferential surface of the guide column, the filter plate is installed on the inner wall of the wellhead body, and the arc-shaped push plate is fixedly connected to the surface of the guide column; the side of the arc-shaped push plate close to the guide column contacts the inner wall of the wellhead body, the top of the arc-shaped push plate contacts the bottom of the filter plate, the circumferential surface of the guide rod contacts the inner wall of the guide groove, The bottom of the guide plate is in contact with the top of the arc plate, and the filter plate in the wellhead device can filter and separate impurities in the oil and saturated steam. When the flange connection leaks and causes the baffle to move up, the baffle will drive the guide plate to move up, and the guide plate will drive the guide rod to move through the guide groove, and the guide rod will drive the guide column to move, and the guide column will drive the arc push plate to move. The arc push plate will push the impurities filtered at the bottom of the filter plate to the middle and gather them, thereby allowing the oil and saturated steam to pass through the filter plate more smoothly, thereby further reducing the internal pressure of the wellhead device during use, and helping the wellhead device to relieve pressure when the flange connection leaks.

[0008] The present invention adopts the above technical solution to bring the following beneficial effects:

[0009] 1. The thermal recovery wellhead with a composite insulation structure cooperates with the wellhead body, wellhead pipe, arc plate, bidirectional screw, elastic telescopic rod, support block, arc strip, pressure block, support rod and support plate to provide support for the entire wellhead device through the support block, thereby improving the overall stability of the device and increasing the supporting area of ​​the support block for the wellhead body, thereby reducing the pressure on the ground and avoiding sinking or collapse of the foundation due to excessive pressure. At the same time, the vibration of the wellhead device during operation is transmitted to the ground, thereby improving the vibration resistance of the device. In addition, an insulation cover can be installed on the surface of the device, and the insulation cover consists of an outer layer and an inner layer. The inner layer is aerogel plus alkali-free glass fiber, and the outer layer is fireproof cloth or silicone coating. The insulation cover is fixed with Velcro, buckles or metal buckles.

[0010] 2. The thermal recovery wellhead with a composite thermal insulation structure operates through the coordinated operation of a moving rod, a transmission plate, a vent, a baffle, an air groove, an extension plate, a slot, and a threaded pipe. When the wellhead device leaks, the vent in the moving rod will connect the wellhead with the threaded pipe, so that the gas and liquid in the wellhead can be discharged directly, and the pressure can be reduced to prevent the flange connection from continuing to leak and pollute the surrounding environment. A collecting pipe is connected to the threaded pipe to collect the gas or liquid discharged due to pressure relief. At the same time, the sensor inside the threaded pipe will detect liquid or gas and sound an alarm to remind workers that a leak has occurred at the wellhead.

[0011] 3. The thermal recovery wellhead with a composite insulation structure can filter and separate impurities in oil and saturated steam through the coordinated operation of the guide plate, guide groove, guide column, guide rod, filter plate and arc-shaped push plate. When the flange connection leaks and the baffle plate moves up, the baffle plate will drive the guide plate to move up, and the guide plate will drive the guide rod to move through the guide groove, and the guide rod will drive the guide column to move, and the guide column will drive the arc-shaped push plate to move. The arc-shaped push plate will push the impurities filtered at the bottom of the filter plate to the middle and gather them, so that oil and saturated steam can pass through the filter plate more smoothly, thereby further reducing the internal pressure of the wellhead device when in use, and helping the wellhead device to relieve pressure when the flange connection leaks. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0013] Figure 2 This is a schematic diagram of the structure of the curved plate of the present invention;

[0014] Figure 3 A half-section view of the wellhead body structure of the present invention;

[0015] Figure 4 This is a schematic diagram of the structure of the curved plate of the present invention;

[0016] Figure 5 This is a schematic diagram of the arc strip structure of the present invention;

[0017] Figure 6 A half-section view of the curved plate structure of the present invention;

[0018] Figure 7 This is a schematic diagram of the filter plate structure of the present invention;

[0019] Figure 8 For the present invention Figure 7 A magnified view of the structure in the middle.

[0020] In the figure: 1. wellhead body; 11. wellhead pipeline; 2. arc plate; 21. bidirectional screw; 22. elastic telescopic rod; 23. support block; 24. arc strip; 25. pressure block; 26. support rod; 27. support plate; 3. pressure relief mechanism; 31. moving rod; 32. transmission plate; 33. vent; 34. baffle; 35. air groove; 36. extension plate; 37. slot; 38. threaded pipe; 4. dredging mechanism; 41. guide plate; 42. guide groove; 43. guide column; 44. guide rod; 45. filter plate; 46. arc push plate. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] See also Figure 1-Figure 8 An embodiment of the present invention is: a thermal recovery wellhead with a composite insulation structure, comprising a wellhead body 1 and an arc plate 2, the surface of the wellhead body 1 is fixedly connected with a wellhead pipe 11, the inner wall of the arc plate 2 is threadedly connected with a bidirectional screw 21, one side of the arc plate 2 is in contact with the wellhead body 1, the other side of the arc plate 2 is fixedly connected with an elastic telescopic rod 22, the end of the elastic telescopic rod 22 away from the arc plate 2 is fixedly connected with a support block 23, the top of the support block 23 is rotatably connected with an arc strip 24, the top of the arc strip 24 is rotatably connected with a pressing block 25, and the top of the arc plate 2 is fixedly connected with the support rod 2 6. The top of the support rod 26 is fixedly connected with a support plate 27. The inner wall of the arc plate 2 is provided with a pressure relief mechanism 3 for assisting drainage and pressure relief when the flange connection leaks. The inner wall of the wellhead body 1 is provided with a dredging mechanism 4 for dredging accumulated impurities and reducing the internal pressure of the wellhead body 1. The support block 23 is placed on the ground, and then the wellhead body 1 is correctly installed. After the wellhead is installed, the bidirectional screw 21 is rotated by a tool, and the bidirectional screw 21 drives the two arc plates 2 to gather together. The arc plates 2 will clamp the flange connection below the wellhead body 1, and at the same time, the two arc plates 2 drive the two support rods 2 6 gather together, the two support rods 26 drive the two support plates 27 to gather together, the support plates 27 will further clamp the wellhead body 1, and provide support for the entire wellhead device through the support block 23, thereby improving the overall stability of the device; the number of arc plates 2 is two, and the two arc plates 2 are symmetrically distributed on the left and right sides of the wellhead body 1, the surface of the wellhead body 1 is sleeved with an insulation sleeve, and the insulation sleeve consists of an outer layer and an inner layer; the inner layer is aerogel plus alkali-free glass fiber, the outer layer is a fireproof cloth or a silicone coating, and the insulation sleeve is fixed with Velcro, buckles or metal buckles; the circumferential surface of the wellhead pipe 11 and the pressure The top of the pressure block 25 contacts the top of the support plate 27, and the side of the support plate 27 away from the support rod 26 contacts the surface of the wellhead body 1. When the wellhead pipe 11 is installed together with the wellhead device, the wellhead pipe 11 will press on the pressure block 25 and push the pressure block 25 to move downward. The pressure block 25 pushes the arc bar 24 to move, and the arc bar 24 pushes the support block 23 to move to the side away from the arc plate 2, so that the two support blocks 23 move in opposite directions and increase the distance between them, thereby increasing the support area of ​​the support block 23 on the wellhead body 1, thereby reducing the pressure on the ground and avoiding sinking or collapse of the foundation due to excessive pressure.

[0023] Working principle: Place the support block 23 on the ground, then correctly install the wellhead body 1. After installing the wellhead, rotate the bidirectional screw 21 through the tool, and the bidirectional screw 21 drives the two arc plates 2 to gather together. The arc plates 2 will clamp the flange connection below the wellhead body 1. At the same time, the two arc plates 2 drive the two support rods 26 to gather together, and the two support rods 26 drive the two support plates 27 to gather together. The support plates 27 will further clamp the wellhead body 1 and provide support for the entire wellhead device through the support block 23 to improve the overall stability of the device. At the same time, when the wellhead pipe 11 is installed together with the wellhead device, the wellhead pipe 11 will press on the pressing block 25 and push the pressing block 25 down. The pressure block 25 pushes the arc strip 24 to move, and the arc strip 24 pushes the support block 23 to move to the side away from the arc plate 2, so that the two support blocks 23 move in opposite directions and increase the distance between them, thereby increasing the support area of ​​the support block 23 on the wellhead body 1, thereby reducing the pressure on the ground and avoiding sinking or collapse of the foundation due to excessive pressure. At the same time, the vibration of the wellhead device during operation is transmitted to the ground, thereby improving the vibration resistance of the device, and an insulation cover can be installed on the surface of the device, and the insulation cover consists of an outer layer and an inner layer, the inner layer is aerogel plus alkali-free glass fiber, the outer layer is fireproof cloth or silicone coating, and the insulation cover is fixed with Velcro, buckles or metal buckles.

[0024] See also Figure 1-Figure 8On the basis of the above embodiment, in another embodiment of the present invention, the pressure relief mechanism 3 includes a moving rod 31, a transmission plate 32, a vent 33 and a baffle 34, the moving rod 31 is slidably connected to the inner wall of the wellhead body 1, the transmission plate 32 is fixedly connected to the circumferential surface of the moving rod 31, the vent 33 is opened inside the moving rod 31, and the baffle 34 is slidably connected to the inner wall of the arc plate 2; the pressure relief mechanism 3 also includes an air groove 35, an extension plate 36, a card groove 37 and a threaded tube 38, the air groove 35 is opened on the arc plate 2 near the wellhead body 1 On one side, the extension plate 36 is fixedly connected to the surface of the arc plate 2, the slot 37 is opened on the surface of the extension plate 36, and the threaded pipe 38 is fixedly connected to the side of the arc plate 2 away from the wellhead body 1. The bottom flange of the wellhead bears greater pressure because it directly bears the original pressure downhole. When the wellhead device is used for a long time, if the bottom flange connection is not repaired in time, it is easy to leak. The bolts at the flange connection become loose, which leads to the leakage of oil or saturated steam through the flange connection. The leaked oil or saturated steam will pass through the slot 37 and the gas groove. The guide of 35 enters the curved plate 2, and the leaked high-pressure gas or liquid will push the baffle plate 34 to move upward. After the baffle plate 34 moves upward, it will no longer block the moving rod 31. At this time, the transmission plate 32 inside the wellhead device will be pushed by the pressure and drive the moving rod 31 to penetrate the curved plate 2, so that the moving rod 31 extends into the threaded tube 38, and the vent hole 33 in the moving rod 31 will connect the wellhead with the threaded tube 38, so that the gas and liquid in the wellhead can be directly discharged, and the pressure is reduced, so as to prevent the flange connection from continuing to leak and pollute the surrounding environment; A sensor is provided on the inner wall of the corrugated tube 38, the slot 37 is connected to the air slot 35, and the circumferential surface of the movable rod 31 is slidably connected to the inner wall of the arc plate 2; the flange connection of the wellhead body 1 is flush with the slot 37 and the air slot 35, the side of the movable rod 31 away from the transmission plate 32 is in contact with the baffle 34, and the extension plate 36 is in contact with the wellhead body 1, and a collecting pipe is connected to the threaded tube 38 for collecting gas or liquid discharged due to pressure relief. At the same time, the sensor inside the threaded tube 38 will sound an alarm when it detects liquid or gas, and remind the workers that a leak has occurred at the wellhead.

[0025] The dredging mechanism 4 includes a guide plate 41, a guide groove 42, a guide column 43, a guide rod 44, a filter plate 45 and an arc-shaped push plate 46. The guide plate 41 is fixedly connected to the top of the baffle 34, the guide groove 42 is provided on the surface of the guide plate 41, the guide column 43 is slidably connected to the inner wall of the wellhead body 1, the guide rod 44 is fixedly connected to the circumferential surface of the guide column 43, the filter plate 45 is installed on the inner wall of the wellhead body 1, and the arc-shaped push plate 46 is fixedly connected to the surface of the guide column 43. The filter plate 45 in the wellhead device can filter and separate impurities in oil and saturated steam; the side of the arc-shaped push plate 46 close to the guide column 43 contacts the inner wall of the wellhead body 1, the top of the arc-shaped push plate 46 contacts the bottom of the filter plate 45, the circumferential surface of the guide rod 44 contacts the inner wall of the guide groove 42, and the bottom of the guide plate 41 contacts the top of the arc-shaped plate 2. When the flange connection leaks and the baffle plate 34 moves upward, the baffle plate 34 will drive the guide plate 41 to move upward, and the guide plate 41 will drive the guide rod 44 to move through the guide groove 42, and the guide rod 44 will drive the guide column 43 to move, and the guide column 43 will drive the arc push plate 46 to move, and the arc push plate 46 will push the impurities filtered at the bottom of the filter plate 45 to the middle and gather them, so that the oil and saturated steam can pass through the filter plate 45 more smoothly, thereby further reducing the internal pressure of the wellhead device during use, helping the wellhead device to relieve pressure when the flange connection leaks, and preventing the filter plate 45 from being blocked, thereby preventing the liquid and gas below the wellhead body 1 from smoothly passing into the upper part and being discharged, thereby causing the pressure in the lower part of the wellhead body 1 to continue to increase, causing the pressure relief of the moving rod 31 to be less than the pressurization of the lower part of the wellhead body 1, so that the wellhead body 1 still has the risk of continuing to leak.

[0026] Working principle: leaked oil or saturated steam will enter the curved plate 2 through the guide of the card slot 37 and the gas slot 35, and the leaked high-pressure gas or liquid will push the baffle 34 to move up. After the baffle 34 moves up, it will no longer block the moving rod 31. At this time, the transmission plate 32 inside the wellhead device will be pushed by the pressure and drive the moving rod 31 to penetrate the curved plate 2, so that the moving rod 31 extends into the threaded pipe 38, and the vent 33 in the moving rod 31 will connect the wellhead with the threaded pipe 38, so that the gas and liquid in the wellhead can be directly discharged, and the pressure is reduced to prevent the flange connection from continuing to leak and pollute the surrounding environment. The threaded pipe 38 is connected with a collecting pipe for collecting the gas or liquid discharged due to pressure relief. At the same time, the sensor inside the threaded pipe 38 will detect liquid or gas and sound an alarm to remind the workers that the wellhead is leaking;

[0027] The filter plate 45 in the wellhead device can filter and separate impurities in oil and saturated steam. When the flange connection leaks and the baffle 34 moves up, the baffle 34 will drive the guide plate 41 to move up, and the guide plate 41 will drive the guide rod 44 to move through the guide groove 42, and the guide rod 44 will drive the guide column 43 to move, and the guide column 43 will drive the arc push plate 46 to move. The arc push plate 46 will push the impurities filtered at the bottom of the filter plate 45 to the middle and gather them, so that the oil and saturated steam can pass through the filter plate 45 more smoothly, thereby further reducing the internal pressure of the wellhead device when in use, and helping the wellhead device to relieve pressure when the flange connection leaks.

[0028] The present invention provides a thermal recovery wellhead with a composite insulation structure. There are many methods and ways to implement the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be considered as the protection scope of the present invention. All components not specified in this embodiment can be implemented using existing technologies.

Claims

1. A thermal recovery wellhead with a composite heat-insulating structure, comprising a wellhead body (1) and an arc-shaped plate (2), characterized in that: The surface of the wellhead body (1) is fixedly connected to a wellhead pipe (11); the inner wall of the arc plate (2) is threadedly connected to a bidirectional screw (21); one side of the arc plate (2) is in contact with the wellhead body (1); the other side of the arc plate (2) is fixedly connected to an elastic telescopic rod (22); one end of the elastic telescopic rod (22) away from the arc plate (2) is fixedly connected to a support block (23); the top of the support block (23) is rotatably connected to an arc strip (24) The top of the arc strip (24) is rotatably connected to a pressure block (25), the top of the arc plate (2) is fixedly connected to a support rod (26), the top of the support rod (26) is fixedly connected to a support plate (27), the inner wall of the arc plate (2) is provided with a pressure relief mechanism (3) for assisting drainage and pressure relief when a flange connection leaks, and the inner wall of the wellhead body (1) is provided with a dredging mechanism (4) for dredging accumulated impurities and reducing the internal pressure of the wellhead body (1).

2. The thermal recovery wellhead with a composite insulation structure according to claim 1, characterized in that: The number of the arc-shaped plates (2) is two, and the two arc-shaped plates (2) are symmetrically distributed on the left and right sides of the wellhead body (1). The surface of the wellhead body (1) is sleeved with a heat-insulating sleeve, and the heat-insulating sleeve consists of an outer layer and an inner layer.

3. The thermal recovery wellhead with a composite insulation structure according to claim 2, characterized in that: The inner layer is aerogel plus alkali-free glass fiber, the outer layer is fireproof cloth or silicone coating, and the thermal insulation cover is fixed by Velcro, buckle or metal buckle.

4. The thermal recovery wellhead with a composite insulation structure according to claim 3, characterized in that: The circumferential surface of the wellhead pipe (11) contacts the top of the pressing block (25), and the side of the support plate (27) away from the support rod (26) contacts the surface of the wellhead body (1).

5. The thermal recovery wellhead with a composite insulation structure according to claim 4, characterized in that: The pressure relief mechanism (3) comprises a moving rod (31), a transmission plate (32), a vent hole (33) and a baffle (34); the moving rod (31) is slidably connected to the inner wall of the wellhead body (1); the transmission plate (32) is fixedly connected to the circumferential surface of the moving rod (31); the vent hole (33) is provided inside the moving rod (31); and the baffle (34) is slidably connected to the inner wall of the arc plate (2).

6. The thermal recovery wellhead with a composite insulation structure according to claim 5, characterized in that: The pressure relief mechanism (3) further comprises an air groove (35), an extension plate (36), a clamping groove (37) and a threaded tube (38); the air groove (35) is provided on a side of the arc plate (2) close to the wellhead body (1); the extension plate (36) is fixedly connected to the surface of the arc plate (2); the clamping groove (37) is provided on the surface of the extension plate (36); and the threaded tube (38) is fixedly connected to a side of the arc plate (2) away from the wellhead body (1).

7. The thermal recovery wellhead with a composite insulation structure according to claim 6, characterized in that: The inner wall of the threaded tube (38) is provided with a sensor, the clamping groove (37) is communicated with the air groove (35), and the circumferential surface of the moving rod (31) is slidably connected with the inner wall of the arc plate (2).

8. The thermal recovery wellhead with a composite insulation structure according to claim 7, characterized in that: The flange connection of the wellhead body (1) is flush with the clamping groove (37) and the air groove (35), the side of the moving rod (31) away from the transmission plate (32) is in contact with the baffle plate (34), and the extension plate (36) is in contact with the wellhead body (1).

9. The thermal recovery wellhead with a composite insulation structure according to claim 8, characterized in that: The dredging mechanism (4) comprises a guide plate (41), a guide groove (42), a guide column (43), a guide rod (44), a filter plate (45) and an arc-shaped push plate (46); the guide plate (41) is fixedly connected to the top of the baffle (34); the guide groove (42) is provided on the surface of the guide plate (41); the guide column (43) is slidably connected to the inner wall of the wellhead body (1); the guide rod (44) is fixedly connected to the circumferential surface of the guide column (43); the filter plate (45) is installed on the inner wall of the wellhead body (1); and the arc-shaped push plate (46) is fixedly connected to the surface of the guide column (43).

10. The thermal recovery wellhead with a composite insulation structure according to claim 9, characterized in that: The side of the arc-shaped push plate (46) close to the guide column (43) contacts the inner wall of the wellhead body (1), the top of the arc-shaped push plate (46) contacts the bottom of the filter plate (45), the circumferential surface of the guide rod (44) contacts the inner wall of the guide groove (42), and the bottom of the guide plate (41) contacts the top of the arc-shaped plate (2).

Images