An underwater Christmas tree cap provided with a gate valve and a fishing net protection cage

Abstract

The application discloses an underwater Christmas tree cap provided with a gate valve and a fishing net protection frame, which comprises a tree cap body, a production channel vertically arranged on the tree cap body, an independent DHPT cable channel and an ESP cable channel, the DHPT cable channel and the ESP cable channel penetrating through the tree cap body, guide blocks I and II arranged around the outer diameter of the bottom of the tree cap body, a plurality of mechanical connectors uniformly connected around the shoulder of the middle part of the tree cap body, a connecting sleeve sleeved on the top of the tree cap body, a top cover embedded on the end of the connecting sleeve away from the tree cap body, a pressure cap adjusted on the outside of the connecting position of the top cover and the connecting sleeve, a direct-reading pressure gauge connected on the top of the top cover, and a fishing net protection frame arranged around the outside of the tree cap body; the application is used for connecting and locking with an underwater oil production body, providing a corresponding connection of the production channel and the cable penetrating channel, and the fishing net protection frame is provided, so that the safety of equipment operation can be ensured.

Description

Technical Field

[0001] This invention belongs to the field of marine oil and gas drilling and production equipment technology, and relates to an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame. Background Technology

[0002] Subsea wellheads are core equipment in offshore oil and gas development, and the wellhead cap, a crucial component of the subsea wellhead, is typically installed at the top. It provides an axial entry point into the tubing space and serves as a backup sealing barrier for production channels and annular pressure. When using wellheads for subsea completion operations, the installation of the wellhead cap is generally the final completion step. After the cap is installed and locked, chemicals are injected into the wellhead bore to displace seawater, preventing corrosion and hydrate formation during later production processes.

[0003] Traditional subsea well caps come in two forms: non-pressure-bearing outer caps and pressure-bearing inner caps. They only function to connect to the well body, provide sealing, or withstand pressure, lacking structures such as underwater cable crossings and anti-fishing net protection frames. Conventional underwater cable crossing methods typically involve connecting the well cap to a corresponding connector on the side or top of the tubing hanger via an independent penetration device on the side of the well body or a wet joint fixed to the bottom of the well body, ultimately connecting to downhole electrical equipment via an in-well cable. This method complicates the structure of the well body and tubing hanger, increasing the process flow and operation time. Furthermore, conventional anti-fishing net protection frames generally need to cover the entire well, resulting in large size and weight; some also require separate lowering and retrieval, increasing operational difficulty and cost. Summary of the Invention

[0004] The purpose of this invention is to provide an underwater oil production tree cap equipped with a gate valve and an anti-fishing net protection frame, which is used to connect and lock with the underwater oil production body, providing underwater corresponding connections for production channels and cable crossing channels. It has its own anti-fishing net protection frame to ensure the safety of equipment operation.

[0005] The technical solution adopted in this invention is a submersible oil production tree cap equipped with a gate valve and an anti-fishing net protective frame, including a tree cap body, a production channel vertically arranged on the tree cap body, and independent downhole temperature and pressure sensor (DHPT) cable channel and electric submersible pump (ESP) cable channel. The downhole temperature and pressure sensor (DHPT) cable channel and the ESP cable channel pass through the tree cap body. Guide block I and guide block II are arranged around the bottom outer diameter of the tree cap body. Multiple mechanical connectors are evenly connected around the shoulder of the middle part of the tree cap body. A connecting sleeve is sleeved on the top of the tree cap body. A top cover is embedded at the end of the connecting sleeve away from the tree cap body. A pressure cap is adjusted on the outside of the connection between the top cover and the connecting sleeve. A direct-reading pressure gauge is connected to the top of the top cover. An anti-fishing net protective frame is also provided around the outside of the tree cap body.

[0006] The invention is further characterized by:

[0007] The upper part of the production channel has a valve cavity profile, and a gate is provided through the valve cavity profile. A valve seat is sleeved on the outer surface of the gate on the production channel, and a driver is connected to one end of the gate.

[0008] The ESP cable channel is located on one side of the production channel. One end of the ESP cable channel extends out of the tree cap body. A rectangular groove I is set on the outside of the tree cap body. The rectangular groove I is close to the end of the ESP cable channel that extends out of the tree cap body. A wet male connector I is installed at the bottom of the ESP cable channel. An EPS electrical connector flange is connected to the top of the ESP cable channel. A wet female connector I is fixed in the rectangular groove I. The EPS electrical connector flange 12 is connected to the wet female connector I.

[0009] The downhole temperature and pressure sensor DHPT cable channel is located on the side of the tree cap body away from the ESP cable channel. The downhole temperature and pressure sensor DHPT cable channel includes a vertical section and an inclined section. The vertical section is located on the production channel side, and the inclined section extends out of the tree cap body. The bottom of the downhole temperature and pressure sensor DHPT cable channel is connected to a combined electrical connector. The top of the combined electrical connector is a dry electrical connector, and the bottom is a wet male connector II. The combined electrical connector is fixed to the vertical section of the downhole temperature and pressure sensor DHPT cable channel by a fixing plate, and an operating port is opened in the middle of the vertical section. The top of the inclined section extending out of the tree cap body is connected to the DHPT electrical connector flange connection. A rectangular groove II is also provided on the outside of the tree cap body. The rectangular groove II is close to the end of the downhole temperature and pressure sensor DHPT cable channel extending out of the tree cap body. A wet female connector II is fixed in the rectangular groove II, and the DHPT electrical connector flange is connected to the wet female connector II.

[0010] The rectangular groove I and rectangular groove II have the same structure, including a top plate III, a fixed upright plate and two side plates III. The wet female connector I or wet female connector II is connected to the fixed upright plate. The top plate III and the two side plates III protrude from the fixed upright plate and surround the wet female connector I or wet female connector II on three sides. The bottom edge III and bottom edge IV of the two side plates III are both beveled. The bottom edge III is attached and fixed to the protective frame, and the bottom edge IV is used to guide the fishing net trolley.

[0011] Guide block I and guide block II are arranged asymmetrically, and guide block I and guide block II cooperate with the corresponding guide grooves on the tubing hanger;

[0012] The mechanical connector has an annular groove. Multiple sets of locking blocks are evenly distributed around one end of the annular groove. One end of the locking block is trapezoidal, and the other end of the locking block has a T-shaped groove. The end of the annular groove away from the locking block is embedded with a drive rod. The drive rod extends into the T-shaped groove of the locking block. The drive rod has a stepped shaft structure. The large end is inserted into the T-shaped groove of the locking block, and the small end face is provided with a wrench hexagon. The end of the drive rod with the wrench hexagon is embedded in a threaded hole with threads on the outside. The middle shoulder of the tree cap body is provided with thread II that mates with the threaded hole.

[0013] The anti-fishing net protection frame is an inverted flared structure, consisting of a polygonal top plate I and multiple inclined side plates I connected together. The side plate I has an opening in the middle. The tree cap body is located inside the anti-fishing net protection frame. The end of the driver that is away from the gate extends out of the side plate I. The side plate I is covered with a rectangular cover at the end of the driver. The rectangular cover includes a top plate II, a front plate, and two side plates II. The front plate has a round hole. The bottom edge I and bottom edge II of the two side plates II are both beveled. The bottom edge I is attached and fixed to the side plate I. The bottom edge II is used to guide the fishing net drag plate. The end of the driver is located in the round hole, and a handwheel is connected to one end of the driver. The handwheel is located in the round hole.

[0014] The vertical production channel is fitted with a seal I on the lower outer diameter, the tree cap body is fitted with a seal II on the middle outer diameter, a gasket is provided between the tree cap body and the connecting sleeve, and a seal III is provided between the top cover and the connecting sleeve.

[0015] The beneficial effects of this invention are:

[0016] This invention provides a fully functional and compact submersible oil production tree cap equipped with a gate valve and an anti-fishing net protective frame. The dual-channel underwater cable structure provides power to downhole equipment and enables signal transmission. Multiple sets of underwater wet electrical connectors allow for multi-channel switching with a single plug-and-play, effectively improving operational efficiency. The gate valve and sealing structure can withstand well pressure and provide a safety barrier for oil and gas wells. The anti-fishing net protective frame is space-saving and lightweight, effectively preventing impacts and damage to the equipment from fishing operations. It employs mechanical connectors, ensuring stable and reliable performance, and meets the high reliability requirements of submersible oil and gas equipment. Attached Figure Description

[0017] Figure 1 This is a top view of an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame according to the present invention;

[0018] Figure 2 This is a AA main sectional view of an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame according to the present invention;

[0019] Figure 3 This is a partial BB cross-sectional view of an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame according to the present invention;

[0020] Figure 4 This is an enlarged view of a mechanical connector locking mechanism for an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame, according to the present invention.

[0021] Figure 5 This is a partial cross-sectional view (CC) of a guide block structure for an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame, according to the present invention.

[0022] Figure 6 This is a DD cross-sectional view of a guide block structure for an underwater oil production tree cap equipped with a gate valve and an anti-fishing net protection frame according to the present invention;

[0023] Figure 7 This is an EE cross-sectional view of an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame according to the present invention;

[0024] Figure 8 This is an isometric view of an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame according to the present invention.

[0025] Figure 9 This is a diagram showing the connection between an underwater oil production tree cap equipped with a gate valve and a fishing net protective frame, and a retrieval tool according to the present invention.

[0026] In the diagram, 1. Tree cap body, 2. Vertical production channel, 3. DHPT cable channel, 4. ESP cable channel, 5. Valve cavity profile, 6. Gate, 7. Valve seat, 8. Actuator, 9. Seal I, 10. Tubing hanger, 11. Wet male connector I, 12. EPS electrical connector flange, 13. Bolt I, 14. Wet female connector I, 15. Protective frame, 16. Rectangular groove I, 17. Combined electrical connector, 18. Dry electrical connector, 19. Wet male connector II, 20. Operating port, 21. Fixing plate, 22. Screw, 23. DHPT electrical connector flange, 24. Bolt II, 25. Wet female connector II, 26. Rectangular groove II, 27. Guide block I, 28. Guide block II, 29. Seal II, 30. Oil production tree body, 31. Thread. Ⅰ, 32. Mechanical connector, 33. Ring groove, 34. Clamping block, 35. Inclined surface Ⅰ, 36. Inclined surface Ⅱ, 37. T-slot, 38. Drive rod, 39. Threaded hole, 40. Hexagonal wrench, 41. Thread Ⅱ, 42. Bolt Ⅲ, 43. Connecting sleeve, 44. Washer ring, 45. Pressure cap, 46. Thread Ⅲ, 47. Top cover, 48. Seal Ⅲ, 49. Direct reading pressure gauge, 50. Top plate Ⅰ, 51. Side plate Ⅰ, 52. Opening, 53. Bolt Ⅳ, 54. Rectangular cover, 55. Top plate Ⅱ, 56. Front panel, 57. Side plate Ⅱ, 58. Round hole, 59. Handwheel, 60. Bottom edge Ⅰ, 61. Bottom edge Ⅱ, 62. Top plate Ⅲ, 63. Fixed upright plate, 64. Side plate Ⅲ, 65. Bottom edge Ⅲ, 66. Bottom edge Ⅳ, 67. Lowering recovery tool. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] This invention provides an underwater oil production tree cap equipped with a gate valve and a fishing net protection frame. The underwater oil production tree cap equipped with a gate valve and a fishing net protection frame includes a tree cap body 1, a protection frame 15, a gate plate 6, a valve seat 7, an actuator 8, an EPS electrical connector flange 12, a DHPT electrical connector flange 23, a mechanical connector 32, a connecting sleeve 43, a pressure cap 45, a top cover 47, a direct-reading pressure gauge 49, as well as various cavities (vertical production channel 2, DHPT cable channel 3, ESP cable channel 4, valve cavity profile 5, annular groove 33, threaded hole 39), electrical connectors (wet male connector I 11, wet female connector I 14, combined electrical connector 17, dry electrical connector 18, wet male connector II 19, wet female connector II 25), cables, seals (seal I 9, seal II 29, gasket 44, seal III 48), hydraulic components, and fasteners (bolt I 13, screw 22, bolt II 24, bolt III 42, bolt IV 53), etc.

[0029] like Figure 2 and Figure 7 As shown, the tree cap body 1 of the device is equipped with a vertical production channel 2 and two independent cable crossing channels (downhole temperature and pressure sensor (DHPT) cable channel 3 and electric submersible pump (ESP) cable channel 4). The upper part of the vertical production channel 2 is provided with a valve cavity profile 5, and a gate 6, a valve seat 7 and a matching actuator 8 are installed. The lower outer diameter of the vertical production channel 2 is provided with a seal I9 for sealing with the production channel on the tubing hanger 10. The bottom of the ESP cable channel 4 is equipped with a wet male connector I11, and the top is connected to the EPS electrical connector flange 12 by bolts I13. The EPS electrical connector flange 12 is connected to the wet female connector I14 through a cable. The wet female connector I14 is fixed in the rectangular groove I16 on the protective frame 15. (Refer to...) Figure 3 As shown, the DHPT cable channel 3 is structurally similar to the ESP cable channel 4. The bottom of the DHPT cable channel 3 is connected to a combined electrical connector 17, where the top of the combined electrical connector 17 is a dry-type electrical connector 18 and the bottom is a wet-type male connector II 19. An operating port 20 is opened in the middle of the vertical section of the DHPT cable channel 3 for the installation and removal of the dry-type electrical connector 18. A fixing plate 21 is provided at the bottom of the DHPT cable channel 3 and is connected to the tree cap body 1 by screws 22. The fixing plate 21 is used to straighten one end of the wet-type male connector II 19 of the combined electrical connector 17. The top of the DHPT cable channel 3 is connected to the DHPT electrical connector flange 23 by bolts II 24. The DHPT electrical connector flange 23 is connected to the wet-type female connector II 25 via a cable. The wet-type female connector II 25 is fixed in the rectangular groove II 26 on the protective frame 15. (Refer to...) Figure 5 , Figure 6As shown, to ensure circumferential alignment of the tree cap and the interfaces at the top of the tubing hanger 10 during the lowering and installation process, guide blocks I 27 and II 28 are asymmetrically arranged on the outer diameter of the bottom of the tree cap body 1. These two blocks respectively mate with the corresponding guide grooves on the tubing hanger 10; furthermore, as... Figure 2 As shown, a seal II 29 is also provided on the outer diameter of the middle part of the tree cap body 1, which is used to seal with the inner diameter of the oil production tree body 30.

[0030] like Figure 2 and Figure 4 As shown, at the shoulder of the tree cap body 1, a mechanical connector 32 is connected via thread I 31. Multiple sets of circumferentially distributed locking blocks 34 are arranged in the annular groove 33 in the middle of the mechanical connector 32. The upper and lower surfaces of the front end of each locking block 34 are provided with inclined surfaces I 35 and II 36. Inclined surface I 35 engages with and presses against the clamping inclined surface on the tree cap body 30. A T-slot 37 is provided at the rear end of the locking block 34 and connects to a drive rod 38. Multiple drive rods 38 are each installed in radially threaded holes 39. The drive rod 38 has a stepped shaft structure, with its large end inserted into the T-slot 37 of the locking block 34 and its small end equipped with a hexagonal wrench 40. Thread II 41 is provided on the shoulder of the tree cap. Rotation of thread II 41 enables the drive rod 38 to move back and forth, ultimately locking or unlocking the locking block 34.

[0031] like Figure 2 As shown, the top of the tree cap body 1 is connected to the connecting sleeve 43 by bolt III 42, and the two are sealed by a gasket 44. The connecting sleeve 43 mainly provides a connection interface for tree cap lowering and retrieval, well repair and other operations. During normal production, the pressure cap 45 is connected to the connecting sleeve 43 by thread III 46, which fixes the top cover 47 and the connecting sleeve 43 into one piece. The two are sealed by sealing III 48. A direct-reading pressure gauge 49 is connected to the upper end of the top cover 47 to monitor the pressure in the channel.

[0032] like Figure 1 , Figure 2 and Figure 8As shown, the anti-fishing net protection frame 15 has an inverted flared structure, consisting of a polygonal top plate I50 and multiple inclined side plates I51 connected together. The side plates I51 also have a roughly rectangular opening 52 in the center for the tool to pass through to rotate the drive rod 38 of the mechanical connector 32. The protection frame 15 is connected to the tree cap body 1 by bolts IV53. To fully protect the components protruding from the protection frame 15, a rectangular cover 54 is provided on the valve actuator 8 side of the protection frame 15. The rectangular cover 54 includes a top plate II55, a front panel 56, and two side plates II57. The front panel 56 has a circular hole 58 for the handwheel 59 of the valve actuator 8 to pass through. The bottom edges I60 and II61 of the side plates II57 are both beveled. The bottom edge I60 is fitted and fixed to the side plate I51 of the protection frame 15, and the bottom edge II61 is used to guide the fishing net trolley. The wet female connector I14 of ESP and the wet female connector II25 of DHPT are respectively provided with rectangular grooves I16 and II26. Both rectangular grooves include a top plate III62, a fixed upright plate 63, and two side plates III64. The wet female connector is connected to the fixed upright plate 63. The top plate III62 and the two side plates III64 protrude from the fixed upright plate 63 and surround the wet female connector on three sides for protection. The bottom edges III65 and IV66 of the two side plates III64 are both beveled. The bottom edge III65 is attached and fixed to the side plate I51 of the protective frame 15, and the bottom edge IV66 is used for guiding the fishing net trawler.

[0033] The working principle of this invention is as follows: When the underwater production tree cap is lowered and installed, the production tree body 30 and the tubing hanger 10 have already been installed in the previous process. By rotating the hexagonal wrench 40 on the drive rod 38 counterclockwise, the drive rod 38 is rotated outward, causing the locking block 34 to retract into the annular groove 33. Rotating the handwheel 59 on the driver 8 clockwise moves the gate plate 6 towards the driver 8, ensuring the valve is in the closed state (e.g., ...). Figure 7 (As shown). Remove the pressure cap 45, top cover 47, and direct-reading pressure gauge 49 from the top of the underwater oil production tree cap, and lower the recovery tool 67 (as shown) via thread III 46. Figure 9 As shown), the wellhead cap and the recovery tool 67 are lowered to near the top of the wellhead body 30 via the drill pipe. The lowering continues slowly, ensuring the bottom of the cap body 1 extends into the bore of the wellhead body 30. When the guide blocks I 27 and II 28 on the outer diameter of the cap body 1 contact the tubing hanger 10, if they are not aligned with the corresponding guide grooves, the wellhead cap needs to be rotated slightly to ensure alignment. The lowering continues until the guide blocks are completely slid into the guide grooves (as shown). Figure 6As shown), the tree cap is placed at the top of the tree body 30. The vertical production channel 2 is connected to the corresponding channel on the tubing hanger 10 and sealed by seal I9. The wet male connector I11 and wet male connector II19 are respectively engaged with and sealed by the corresponding wet female connectors. The lower space between the tree cap body 1 and the tree body 30 is sealed by seal II29. At this time, the locking block 34 is aligned with the corresponding locking groove on the tree body 30. The diver inserts a torque tool into one end of the wrench hexagon 40 connected to the drive rod 38 through the opening 52 on the protective frame 15, rotates the drive rod 38 clockwise, and screws it inward, pushing the locking block 34 into the locking groove of the tree body 30. The inclined surface I35 contacts and presses against the inclined surface on the tree body 30 (as shown). Figure 4 (As shown). The locking operations of the other multiple locking blocks 34 are as described above, ultimately achieving complete locking between the mechanical connector 32 and the wellhead body 30. Wet female connector I 14 and wet female connector II 25 are connected to their corresponding wet male connectors, and the connectivity of the two cable channels from the water surface to the well is tested. After the test, the retrieval tool 67 is removed from the connecting sleeve 43 and retrieved via drill pipe. The pressure cap 45, top cover 47, and direct-reading pressure gauge 49 are connected to the connecting sleeve 43 via thread III 46 (as shown). Figure 2 As shown), seal Ⅲ48 isolates the vertical production channel 2 from seawater, and the direct-reading pressure gauge 49 can be used to observe the pressure condition inside the tree cap bore, providing pressure indication before disassembling components such as the pressure cap 45, ensuring the safety of operators.

[0034] During normal production operations of the subsea wellhead, the gate 6 and valve seat 7 act as a barrier between the oil and gas medium and seawater, and are generally in a normally closed state. The power supply and function adjustment of the subsea electric submersible pump are completed through the ESP cable channel 4. Downhole temperature, pressure and other parameter information are transmitted to the surface control unit for monitoring and recording through the DHPT cable channel 3. For shallow-water offshore oil and gas fields, fishing vessels may be engaged in fishing activities in the water. When the fishing net trolley is towed underwater, when it comes into contact with the wellhead cap, it will slide obliquely upward along the side plate I51 of the protective frame 15 and eventually cross the wellhead cap, avoiding damage to the main pressure-bearing components such as the cap body 1. For the areas on one side of the actuator 8, wet female connector I14 and wet female connector II25 that have protrusions from the inclined surface of the side plate I51, rectangular covers 54, rectangular grooves I16 and II26 are respectively provided (e.g. Figure 8 As shown), it can effectively protect the protruding components and provide secondary guidance for fishing net drapes through bottom edge II61 and bottom edge IV66.

[0035] During subsea wellhead maintenance, gate 6 needs to be opened to lower or retrieve the wire rope plug or other downhole tools from tubing hanger 10.

[0036] When the submersible oil production tree cap is unlocked and retrieved, rotate the handwheel 59 on the drive 8 counterclockwise to open the gate 6. Observe the pressure reading on the direct-reading pressure gauge 49 to confirm that there is no pressure in the tree cap's passage. Then, rotate the handwheel 59 clockwise to close the valve. Remove the pressure cap 45, top cover 47, and direct-reading pressure gauge 49. Lower the oil production tree cap into the retrieval tool 67 using the drill pipe and connect it to the connecting sleeve 43 via thread III 46 (e.g., ...). Figure 9 (As shown). Disconnect wet female connector I14 and wet female connector II25 from their corresponding wet male connectors. The diver inserts a torque tool into one end of the hexagonal wrench 40 connected to the drive rod 38 through the opening 52 on the protective frame 15, and rotates the drive rod 38 counterclockwise to twist it outward, causing the locking block 34 to retract into the annular groove 33, and the inclined surface I35 to disengage from the inclined surface on the production tree body 30. Unlock the other locking blocks 34 in sequence according to the above operation, and finally achieve complete unlocking of the mechanical connector 32 from the production tree body 30. Slowly pull the production tree cap upward by lowering the recovery tool 67 until the vertical production channel 2 is disconnected from the corresponding channel on the tubing hanger 10, the wet male connector I11 and wet male connector II19 are disconnected from their corresponding wet female connectors, and the guide block I27 and guide block II28 disengage from the corresponding guide groove on the tubing hanger 10. Continue to pull the tree cap upwards until the tree cap body 1 is completely removed from the diameter of the tree body 30, and finally the tree cap is recovered to the water surface.

[0037] The technical advantages of this invention are as follows: This subsea oil production tree cap is fully functional and compact, equipped with a gate valve, dual cable channels, and an anti-fishing net structure; the dual underwater cable channels can provide power to downhole equipment and enable signal transmission; the design of multiple sets of underwater wet electrical connectors allows for multiple circuit switching with a single plug-and-play, effectively improving operational efficiency; the gate valve and sealing structure can withstand well pressure, providing a barrier for the safety of oil and gas wells; the anti-fishing net protective frame occupies little space and is lightweight, effectively preventing impacts and damage to the equipment that may be caused by fishing operations; it adopts mechanical connectors, ensuring stable and reliable performance; and it meets the high reliability requirements of subsea oil and gas equipment.

Claims

1. An underwater Christmas tree cap provided with a gate valve and a fishing net protection cage, characterized in that, The tree cap body (1) is vertically provided with a production channel (2), and further comprises independent DHPT cable channel (3) and ESP cable channel (4), the DHPT cable channel (3) and ESP cable channel (4) pass through the tree cap body (1), the tree cap body (1) is provided with guide block I (27) and guide block II (28) around the bottom outer diameter, a plurality of mechanical connectors (32) are uniformly connected around the shoulder of the middle part of the tree cap body (1), the tree cap body (1) is sleeved with a connecting sleeve (43) at the top, the end of the connecting sleeve (43) away from the tree cap body (1) is embedded with a top cover (47), the outside of the connecting part of the top cover (47) and the connecting sleeve (43) is adjusted with a pressure cap (45), a direct-reading pressure gauge (49) is connected to the top of the top cover (47), and a fishing net protection frame (15) is further arranged around the outside of the tree cap body (1). The fishing net protection frame (15) is a reversed horn structure, which is composed of a polygonal top plate I (50) and a plurality of inclined side plates I (51), the middle part of the side plate I (51) is provided with an opening (52), the tree cap body (1) is located in the fishing net protection frame (15), one end of the driver (8) away from the gate plate (6) extends out of the side plate I (51), the side plate I (51) is provided with a rectangular cover (54) covering the extension end of the driver (8), the rectangular cover (54) comprises a top plate II (55), a front panel (56) and two side plates II (57), wherein a circular hole (58) is formed in the front panel (56), the bottom edge I (60) and the bottom edge II (61) of the two side plates II (57) are both inclined edges, wherein the bottom edge I (60) is fixedly connected with the side plate I (51), and the bottom edge II (61) is used for guiding the fishing net drag plate, the end of the driver (8) is located in the circular hole (58), and the one end of the driver (8) is connected with a hand wheel (59), and the hand wheel (59) is located in the circular hole (58).

2. An underwater Christmas tree cap provided with a gate valve and a fishing net protection cage according to claim 1, characterized in that, The upper part of the production channel (2) is provided with a valve cavity profile (5), the gate plate (6) is arranged through the valve cavity profile (5), the outer surface of the gate plate (6) is sleeved with a valve seat (7) outside the production channel (2), and one end of the gate plate (6) is connected with a driver (8).

3. An underwater Christmas tree cap provided with a gate valve and a fishing net protection cage according to claim 1, characterized in that, The ESP cable channel (4) is located on one side of the production channel (2), one end of the ESP cable channel (4) extends out of the tree cap body (1), a rectangular groove I (16) is arranged outside the tree cap body (1), the rectangular groove I (16) is close to the end of the ESP cable channel (4) extending out of the tree cap body (1), a wet male connector I (11) is arranged at the bottom of the ESP cable channel (4), an EPS electrical connector flange (12) is connected to the top of the ESP cable channel (4), a wet female connector I (14) is fixed in the rectangular groove I (16), and the EPS electrical connector flange (12) is connected with the wet female connector I (14).

4. An underwater Christmas tree cap provided with a gate valve and a fishing net protection cage according to claim 3, characterized in that, The DHPT cable channel (3) is located on the side of the tree cap body (1) away from the ESP cable channel (4), the DHPT cable channel (3) comprises a vertical section and an inclined section, the vertical section is located on one side of the production channel (2), the inclined section extends out of the tree cap body (1), the bottom of the DHPT cable channel (3) is connected with the combined electrical connector (17), the top of the combined electrical connector (17) is a dry electrical connector (18), the bottom is a wet male connector II (19), the combined electrical connector (17) is fixed to the vertical section of the DHPT cable channel (3) through the fixing plate (21), and the middle part of the vertical section is provided with an operation opening (20), and the top of the inclined section extending out of the tree cap body (1) is connected with a DHPT connector flange (23), and the outer side of the tree cap body (1) is also provided with a rectangular groove II (26), which is close to the end of the DHPT cable channel (3) extending out of the tree cap body (1), and the wet female connector II (25) is fixedly connected in the rectangular groove II (26), and the DHPT connector flange (23) is connected with the wet female connector II (25).

5. An underwater Christmas tree cap provided with a gate valve and a net guard according to claim 4, characterized in that, The rectangular groove I (16) and the rectangular groove II (26) are the same structure, comprising a top plate III (62), a fixed vertical plate (63) and two side plates III (64), the wet female connector I (14) or the wet female connector II (25) is connected to the fixed vertical plate (63), the top plate III (62) and the two side plates III (64) protrude from the fixed vertical plate (63) and surround the wet female connector I (14) or the wet female connector II (25) from three sides, the bottom edge III (65) and the bottom edge IV (66) of the two side plates III (64) are both inclined edges, the bottom edge III (65) is fixedly connected with the fishing net protection frame (15), and the bottom edge IV (66) is used for guiding the fishing net drag plate.

6. An underwater Christmas tree cap provided with a gate valve and a net guard according to claim 1, characterized in that, The guide block I (27) and the guide block II (28) are asymmetrically arranged, and the guide block I (27) and the guide block II (28) are matched with corresponding guide grooves on the tubing hanger (10).

7. An underwater Christmas tree cap provided with a gate valve and a net guard according to claim 1, characterized in that, The ring groove (33) is provided in the mechanical connector (32), a plurality of groups of clamping blocks (34) are uniformly arranged in the ring groove (33) along the circumferential direction of the ring groove (33) at one end in the ring groove (33), one end of the clamping block (34) is trapezoidal, a T-shaped groove (37) is formed at the other end of the clamping block (34), a driving rod (38) is embedded at the end of the ring groove (33) away from the clamping block, the driving rod (38) extends into the T-shaped groove (37) of the clamping block (34), the driving rod (38) is a stepped shaft type structure, a large end is inserted into the T-shaped groove (37) of the clamping block (34), and a small end face is provided with a wrench hexagon (40), one end of the driving rod (38) provided with the wrench hexagon (40) is embedded into a threaded hole (39) provided with a thread on the outside, and a thread II (41) matched with the threaded hole (39) is arranged on the middle shoulder of the tree cap body (1).

8. An underwater Christmas tree cap provided with a gate valve and a net guard according to claim 1, characterized in that, The production channel (2) is provided with a seal I (9) on the outer diameter of the lower part, the tree cap body (1) is provided with a seal II (29) on the outer diameter of the middle part, a gasket (44) is arranged between the tree cap body (1) and the connecting sleeve (43), and a seal III (48) is arranged between the top cover (47) and the connecting sleeve (43).

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