Underwater Christmas tree wellhead connector testing device and method under complex load effect

Abstract

The invention relates to the technical field of offshore oil engineering, and discloses a device and method for testing a wellhead connector of an underwater Christmas tree under the action of a complex load.The device comprises a testing bottom plate, the testing bottom plate is connected with a loading frame through an axial loading mechanism, and the axial loading mechanism is used for axially applying a load; the loading frame is connected with an upper torsion mechanism, the upper torsion mechanism is used for providing a torsion load in the testing process, the tail end of the lower side of the upper torsion mechanism is connected with an upper clamping mechanism, and complex loads can be simulated: through cooperative work of multiple sets of loading systems, the complex loads under actual working conditions can be simulated; the performance of the connector can be reflected more truly; the high-precision sensor and the data acquisition system are adopted, so that the deformation and stress distribution of the connector can be accurately measured; the automation degree is high, automatic testing is achieved through a control system, the testing efficiency is improved, and personal errors are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of marine petroleum engineering, and in particular relates to a device and method for testing an underwater Christmas tree wellhead connector under complex loads. Background Art

[0002] The subsea tree wellhead connector is a critical device connecting the subsea tree to the subsea wellhead. Its performance directly impacts the safe development of oil and gas fields. Under actual operating conditions, the subsea tree wellhead connector is subjected to complex loads, including pressure, axial force, bending moment, and torque. Therefore, comprehensive performance testing of the subsea tree wellhead connector is crucial.

[0003] Currently, existing underwater Christmas tree wellhead connector testing devices and methods have the following main deficiencies: (1) Single loading method: It can only simulate a single or simple load condition and cannot truly reflect the complex loads under actual working conditions.

[0004] (2) Low test accuracy: Due to the lack of high-precision sensors and data acquisition systems, it is difficult to accurately measure the deformation and stress distribution of the connector.

[0005] (3) Low degree of automation: The testing process mainly relies on manual operation, which is inefficient and prone to human errors. Summary of the Invention

[0006] In view of the above situation, in order to overcome the defects of the prior art, the present invention provides a device and method for testing a wellhead connector of an underwater Christmas tree under complex loads, which effectively solves the problems mentioned in the above background technology.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: A device for testing an underwater Christmas tree wellhead connector under complex loads, comprising a test base plate, wherein the test base plate is connected to a loading frame via an axial loading mechanism, wherein the axial loading mechanism is used to apply an axial load, wherein the loading frame is connected to an upper torsion mechanism, wherein the upper torsion mechanism is used to provide a torsional load during testing, wherein an upper clamping mechanism is connected to a lower end of the upper torsion mechanism, wherein the upper clamping mechanism is used to clamp the upper end of the wellhead connector under test, wherein a lower torsion mechanism is provided on the test base plate, wherein the lower torsion mechanism is used to provide a torsional load during testing, wherein a lower clamping mechanism is connected to the lower torsion mechanism, wherein the lower clamping mechanism is used to clamp the lower end of the wellhead connector under test, and wherein a monitoring mechanism is connected to the test base plate, wherein the monitoring mechanism is used to monitor deformation and applied load during testing.

[0008] Preferably, the lower clamping mechanism includes a lower cylinder, an annular lower clamping cavity is provided in the lower cylinder, a lower driving gear shaft is rotatably connected between the end walls of the lower clamping cavity, the lower driving gear shaft is connected to the power of the lower clamping motor fixedly installed in the lower cylinder, a lower driving gear is fixedly installed on the lower driving gear shaft, the lower driving gear is meshed with the lower part of the lower annular rack, the lower annular rack is rotatably installed between the end walls of the lower clamping cavity, a plurality of lower driven gears are meshed on the upper side of the lower annular rack, and the lower driven gear is fixedly installed on the lower clamping wire The outer surface of the rod, the lower clamping screw is rotatably installed between the end wall of the lower clamping cavity, the outer surface of the lower clamping screw is threadedly connected with a lower threaded cylinder, the lower threaded cylinder is slidably connected to the end wall of the lower clamping cavity and extends to the inside of the lower cylinder body, the end of the lower clamping cavity is fixedly connected with a lower clamping plate, the lower clamping plate clamps the outer surface of the lower end of the wellhead connector, and the outer surface of the lower clamping plate is provided with an anti-slip material, the outer surface of the lower driving gear shaft is fixedly installed with a transmission main bevel gear, the transmission main bevel gear is meshed with the transmission sub-bevel gear, the transmission The auxiliary bevel gear is fixedly mounted on the upper end of the transmission bevel gear shaft, and the transmission bevel gear shaft is rotatably mounted on the bottom wall of the lower clamping cavity and extends into the pulley cavity provided at the lower side of the lower clamping cavity. A toothed pulley 1 is fixedly mounted on the lower end of the transmission bevel gear shaft, and the toothed pulley 1 and the toothed pulley 2 are connected by a toothed belt, and the toothed pulley 2 is fixedly mounted on the lower end of the pulley shaft, and the pulley shaft is rotatably mounted on the upper end wall of the pulley cavity and extends into the tightening bevel gear cavity provided in the column, and the column is fixedly mounted on the bottom wall of the lower cylinder, and the upper side of the pulley shaft is fixedly mounted The end is fixedly connected with a tightening active bevel gear, and a plurality of tightening driven bevel gears are meshed and connected to the tightening active bevel gear. The tightening driven bevel gears are arranged along the circumferential direction of the tightening active bevel gear. The tightening driven bevel gear is fixedly installed on the end of the tightening screw rod, and the tightening screw rod is rotatably installed on the end wall of the tightening bevel gear cavity. A tightening nut cylinder is threadedly connected to the tightening screw rod, and the tightening nut cylinder is slidably connected to the column. The end of the tightening nut cylinder is fixedly connected with a tightening plate, and the tightening plate is tightened to the inner side of the lower part of the wellhead connector, and the outer surface of the tightening plate is provided with anti-slip material.

[0009] The worm gear is connected with the worm gear of the driven gear, and the worm gear is connected with the worm gear of the driven gear to the worm gear of the driven gear.

[0010] Preferably, the axial loading mechanism includes two groups of fixed blocks symmetrically arranged on the test base plate, the two fixed blocks on the same side form a group, and the fixed blocks on the same side are rotatably connected with a connecting shaft, a hydraulic cylinder is fixedly installed on the outer surface of the connecting shaft, a hydraulic rod is slidably connected in the hydraulic cylinder, and an articulated shaft is fixedly installed on the upper end of the hydraulic rod, and the articulated shaft is hinged in a movable groove, and the movable groove is symmetrically arranged at the lower part of the loading frame, an axial braking cavity is provided in the fixed block, an axial loading braking gear is fixedly installed on the outer surface of the connecting shaft in the axial braking cavity, the axial loading braking gear is meshed with the axial loading braking gear, the axial loading braking gear is fixedly installed and powered by an axial braking electric push rod, and the axial braking electric push rod is fixedly installed on the bottom wall of the axial braking cavity, an oil filling hole is provided on the hydraulic cylinder, and the oil filling hole is connected to one end of an oil delivery pipe, and the other end of the oil delivery pipe is connected to a hydraulic pump, the hydraulic pump is fixedly installed on the oil tank, and the oil tank is fixedly installed on the test base plate, and the hydraulic pump is connected to an extraction pipe, and the extraction pipe extends into the oil tank.

[0011] Preferably, the upper torsion mechanism includes an upper torsion cavity provided in the loading frame, a driving bevel gear shaft is rotatably connected to the end wall of the upper torsion cavity, the driving bevel gear shaft is power-connected to the upper torsion motor fixedly installed in the loading frame, the end of the driving bevel gear shaft is fixedly connected to the torsion driving bevel gear, the torsion driving bevel gear is meshed with the torsion driven bevel gear, the torsion driven bevel gear is fixedly installed on the upper end of the upper torsion shaft, the upper torsion shaft passes through and is rotatably connected to the bottom wall of the upper torsion cavity, a flip chute is provided on the end wall of the upper torsion cavity, an electric screw is rotatably connected between the end walls of the flip chute, and the outer surface of the electric screw is threadedly connected to a threaded The pawl is engaged with the gear train of the driven gear and the gear train is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is engaged with the gear of the driven gear and the gear is

[0012] Preferably, the upper clamping mechanism includes an upper cylinder fixedly connected to the lower end of the upper torsion shaft, an upper clamping cavity is provided in the upper cylinder, an upper driving gear shaft is rotatably connected between the end walls of the upper clamping cavity, the upper driving gear shaft is connected to the upper clamping motor fixedly installed in the upper cylinder, an upper driving gear is fixedly connected to the outer surface of the upper driving gear shaft, the upper driving gear is meshed with the upper side of the upper annular rack, and the upper annular rack is rotatably installed at the end of the upper clamping cavity The upper side of the upper annular rack is meshed with a plurality of upper driven gears, and the upper driven gear is fixedly mounted on the outer surface of the upper clamping screw rod, and the upper clamping screw rod is rotatably mounted between the end walls of the upper clamping cavity. The outer surface of the upper clamping screw rod is threadedly connected with an upper threaded cylinder, and the upper threaded cylinder is slidably connected to the end wall of the upper clamping cavity and extends to the inner side of the upper cylinder body. The inner end of the upper threaded cylinder is fixedly connected with an upper clamping plate, and the upper clamping plate is provided with anti-slip material.

[0013] Preferably, the monitoring mechanism includes an operating console provided on the test base plate, corresponding control buttons are provided on the operating console, a display panel is integrated on the operating console, a control processor is provided in the operating console, a corresponding control processing program is provided in the control processor, a plurality of signal lines are connected to the operating console, the operating console and the strain gauge are connected through the signal lines, the strain gauge is adhered to the outer surface of the wellhead connector, the operating console and the monitoring sensor are connected through the signal lines, and the monitoring sensor is detachably connected to the outer surface of the wellhead connector.

[0014] Preferably, a sealing test mechanism is connected to the lower cylinder, and the sealing test mechanism includes a gas channel provided in the lower cylinder, a lower elastic sealing gasket is detachably installed on the inner bottom wall of the lower cylinder, the gas channel passes through the inner bottom wall of the lower cylinder and extends to the upper side of the lower elastic sealing gasket, a pressure sensor is installed on the inner bottom wall of the lower cylinder near the column position, and a ventilation annular frame is rotatably connected to the end wall of the lower cylinder, the ventilation annular frame is connected to the gas channel, the ventilation annular frame and the lower cylinder are sealed, the ventilation annular frame is connected to one end of an air supply pipe and is connected to the inside of the ventilation annular frame, the other end of the air supply pipe is connected to an air pump fixedly installed on the test base plate, and a control valve is installed at the outlet position of the gas channel on the bottom wall of the lower cylinder.

[0015] Preferably, an electrical socket is provided on the lower cylinder.

[0016] The present invention provides a method for testing a wellhead connector of an underwater Christmas tree under complex loads. The method is based on any of the above-mentioned devices for testing a wellhead connector of an underwater Christmas tree under complex loads, and the steps include: Step 1: Insert the plug into the power socket to power the entire device; Step 2: placing the wellhead connector between the lower cylinder and the upper cylinder, causing the axial loading mechanism to move, thereby clamping the wellhead connector between the lower cylinder and the upper cylinder; Step 2: The lower clamping mechanism moves to clamp and support the lower part of the wellhead connector and to support the inner side of the wellhead connector to ensure the reliability of the clamping and prevent slippage; Step 3: The upper clamping mechanism moves to clamp the upper portion of the wellhead connector; Step 4: After the clamping is completed, the axial loading mechanism moves to realize the loading of the axial load, and by controlling the extension of the two hydraulic rods differently, the axial load loading test is realized after tilting at a certain angle; Step 5: The upper torsion mechanism moves to apply a torsional load in a unilateral direction to the wellhead connector. When the torsional loads in two different directions are increased, the lower torsion mechanism moves in a direction opposite to the direction in which the upper torsion mechanism increases the torsional load, thereby applying torsional loads in two different directions. Step 6: Monitoring the movement of the mechanism to monitor the changes of the wellhead connector under various loads; Step 7: The sealing test mechanism moves, thereby performing a sealing test on the wellhead connector.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention provides a testing device for an underwater Christmas tree wellhead connector under complex loads, which can simulate complex loads: by cooperating with multiple loading systems, it can simulate complex loads under actual working conditions and more realistically reflect the performance of the connector.

[0018] The present invention provides a device for testing underwater Christmas tree wellhead connectors under complex loads, with high testing accuracy: by adopting high-precision sensors and data acquisition systems, the deformation and stress distribution of the connector can be accurately measured.

[0019] 3. The present invention provides a device for testing underwater Christmas tree wellhead connectors under complex loads, which has a high degree of automation: automated testing is achieved through a control system, thereby improving test efficiency and reducing human errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. They are used to explain the present invention together with the embodiments of the present invention and do not constitute a limitation of the present invention.

[0021] In the attached figure: Figure 1 This is a schematic diagram of the first direction structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 2 This is a schematic diagram of the second direction structure of a subsea tree wellhead connector testing device under complex loads in the present invention. Figure 3 This is a schematic diagram of the third-direction structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 4 This is a schematic diagram of the structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads in the fourth direction of the present invention; Figure 5 This is a schematic diagram of the fifth direction structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 6 This is a schematic diagram of a first disassembled structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 7 This is a schematic diagram of a second split structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 8 This is a schematic diagram of a third disassembled structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 9 This is a schematic diagram of the fourth disassembled structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 10 This is a schematic diagram of a first partial cross-sectional structure of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 11 This is a second partial cross-sectional structural schematic diagram of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 12 This is a third partial cross-sectional structural schematic diagram of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 13 This is a fourth partial cross-sectional structural schematic diagram of a device for testing a wellhead connector of an underwater Christmas tree under complex loads according to the present invention; Figure 14 for Figure 10 Schematic diagram of the enlarged structure at point A in the middle.

[0022] In the figure: 1-test base plate, 2-fixed block, 3-hydraulic cylinder, 4-oil pipeline, 5-hydraulic pump, 6-oil tank, 7-movable tank, 8-loading frame, 9-monitoring sensor, 10-upper cylinder, 11-wellhead connector, 12-lower cylinder, 13-operating table, 14-mounting cylinder, 15-mounting block, 16-air pump, 17-air pipeline, 18-hydraulic rod, 19-articulated shaft, 20-upper torsion shaft, 21-strain gauge, 22-connecting shaft, 90-upper sealing elastic pad, 24-mounting shaft, 25-electric screw, 26-screw Patterned plate, 27- flip plate, 28- torsion spring, 29- ratchet shaft, 30- ratchet, 31- torsion driven bevel gear, 32- torsion driving bevel gear, 33- driving bevel gear shaft, 34- upper torsion motor, 35- upper ratchet, 36- lower ratchet, 89- gas channel, 38- upper annular rack, 39- upper clamping plate, 40- upper driven gear, 41- upper clamping screw, 42- upper driving gear, 43- upper driving gear shaft, 44- upper threaded cylinder, 45- axial loading brake gear, 46- axial loading brake Tooth, 47-axial brake electric push rod, 48-brake threaded plate, 49-engaging brake teeth, 50-engaging brake gear, 51-brake electric screw, 52-worm, 53-worm shaft, 54-worm wheel, 55-worm wheel shaft, 56-ventilation annular frame, 57-lower side annular rack, 58-lower side clamping screw, 59-lower side splint, 60-lower side threaded barrel, 61-lower side driven gear, 62-lower side driving gear shaft, 63-lower side driving gear, 64-upper side torsion chamber, 65-flip chute, 66-electric shaft, 67-upper side Clamping cavity, 68-lower side clamping cavity, 69-axial braking cavity, 70-cavity, 71-extraction tube, 72-transmission main bevel gear, 73-transmission sub-bevel gear, 74-transmission bevel gear shaft, 75-pulley cavity, 76-toothed pulley 1, 77-toothed belt, 78-toothed pulley 2, 79-lower side elastic sealing gasket, 80-pressure sensor, 81-column, 82-tightening bevel gear cavity, 83-tightening active bevel gear, 84-tightening plate, 85-tightening nut cylinder, 86-tightening driven bevel gear, 87-pulley shaft, 88-tightening screw. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] like Figure 1-14As shown, the present invention provides an underwater oil tree wellhead connector testing device under complex loads, including a test base plate 1, the test base plate 1 is connected to a loading frame 8 via an axial loading mechanism, the axial loading mechanism is used to apply an axial load, the loading frame 8 is connected to an upper torsion mechanism, the upper torsion mechanism is used to provide a torsional load during the test, the lower end of the upper torsion mechanism is connected to an upper clamping mechanism, the upper clamping mechanism is used to clamp the upper end of the tested wellhead connector 11, the test base plate 1 is provided with a lower torsion mechanism, the lower torsion mechanism is used to provide a torsional load during the test, the lower torsion mechanism is connected to a lower clamping mechanism, the lower clamping mechanism is used to clamp the lower end of the tested wellhead connector 11, and the test base plate 1 is connected to a monitoring mechanism, the monitoring mechanism is used to monitor the deformation and applied load during the test.

[0025] Advantageously, the lower clamping mechanism includes a lower cylinder 12, a ring-shaped lower clamping cavity 68 is provided in the lower cylinder 12, a lower driving gear shaft 62 is rotatably connected between the end walls of the lower clamping cavity 68, the lower driving gear shaft 62 is connected to the power of the lower clamping motor fixedly installed in the lower cylinder 12, a lower driving gear 63 is fixedly installed on the lower driving gear shaft 62, the lower driving gear 63 is meshed with the lower part of the lower annular rack 57, the lower annular rack 57 is rotatably installed between the end walls of the lower clamping cavity 68, the upper side of the lower annular rack 57 is meshed with a plurality of lower driven gears 61, and the lower driven gear 61 is fixedly installed on the lower clamping screw 58 The outer surface of the lower clamping screw 58 is rotatably installed between the end walls of the lower clamping cavity 68. The outer surface of the lower clamping screw 58 is threadedly connected with a lower threaded barrel 60. The lower threaded barrel 60 is slidably connected to the end wall of the lower clamping cavity 68 and extends to the inner side of the lower cylinder 12. The end of the lower clamping cavity 68 is fixedly connected with a lower clamping plate 59. The lower clamping plate 59 clamps the outer surface of the lower end of the wellhead connector 11, and the outer surface of the lower clamping plate 59 is provided with an anti-slip material. The outer surface of the lower driving gear shaft 62 is fixedly installed with a transmission main bevel gear 72. The transmission main bevel gear 72 is meshed with the transmission sub-bevel gear 73. The transmission sub-bevel gear 73 is meshed with the transmission sub-bevel gear 73. 3 is fixedly mounted on the upper end of the transmission bevel gear shaft 74, and the transmission bevel gear shaft 74 is rotatably mounted on the bottom wall of the lower clamping cavity 68 and extends into the pulley cavity 75 provided on the lower side of the lower clamping cavity 68. A toothed pulley 1 76 is fixedly mounted on the lower end of the transmission bevel gear shaft 74, and the toothed pulley 1 76 is connected to the toothed pulley 2 78 by a toothed belt 77. The toothed pulley 2 78 is fixedly mounted on the lower end of the pulley shaft 87, and the pulley shaft 87 is rotatably mounted on the upper end wall of the pulley cavity 75 and extends into the tightening bevel gear cavity 82 provided in the column 81. The column 81 is fixedly mounted on the inner bottom wall of the lower cylinder 12. The end is fixedly connected with a tightening active bevel gear 83, and a plurality of tightening driven bevel gears 86 are meshed and connected to the tightening active bevel gear 83. The tightening driven bevel gears 86 are arranged along the circumferential direction of the tightening active bevel gear 83. The tightening driven bevel gear 86 is fixedly mounted on the end of a tightening screw rod 88, and the tightening screw rod 88 is rotatably mounted on the end wall of the tightening bevel gear cavity 82. A tightening nut cylinder 85 is threadedly connected to the tightening screw rod 88, and the tightening nut cylinder 85 is slidably connected to the column 81. The end of the tightening nut cylinder 85 is fixedly connected to a tightening plate 84, and the tightening plate 84 is tightened to the inner side of the lower part of the wellhead connector 11. The outer surface of the tightening plate 84 is provided with an anti-slip material. During operation, the wellhead connector 11 enters the lower cylinder 12, the column 81 enters the interior of the lower end of the wellhead connector 11, and the lower clamping motor is started, thereby driving the lower driving gear shaft 62 to rotate, thereby driving the lower driving gear 63 to rotate, and the lower driving gear 63 is engaged with the lower annular rack 57, thereby driving the lower annular rack 57 to rotate, and the lower annular rack 57 is engaged with the lower driven gear 61, thereby driving the lower clamping screw 58 to rotate, thereby pushing the lower threaded cylinder 60 to move, thereby pushing the lower clamping plate 59 to move to clamp the outer surface of the lower end of the wellhead connector 11, and when the lower driving gear shaft 62 rotates, it drives the transmission main cone The gear 72 rotates, and the transmission main bevel gear 72 meshes with the transmission secondary bevel gear 73, thereby driving the transmission bevel gear shaft 74 to rotate, thereby causing the toothed pulley 1 76 to rotate, and the toothed pulley 1 76 and the toothed pulley 2 78 are meshed and connected for transmission via the toothed belt 77, thereby driving the pulley shaft 87 to rotate, thereby driving the tightening active bevel gear 83 to rotate, and the tightening active bevel gear 83 meshes with the tightening driven bevel gear 86, thereby driving the tightening screw 88 to rotate, thereby pushing the tightening plate 84 to move, thereby pushing the tightening plate 84 to move to clamp the inner side of the wellhead connector 11, thereby clamping the lower side of the wellhead connector 11, ensuring stability during the test process.

[0026] Advantageously, the lower torsion mechanism includes a mounting block 15 symmetrically fixedly mounted on the test base plate 1, wherein a cavity 70 is provided in the mounting block 15, and a mounting shaft 24 is rotatably connected through the end walls of the cavity 70, and an engaging brake gear 50 is fixedly mounted on the outer surface of the mounting shaft 24 in the cavity 70, and the engaging brake gear 50 is engaged with the engaging brake teeth 49, and the engaging brake teeth 49 are fixedly mounted on the inner surface of the braking threaded plate 48, and the braking threaded plate 48 is threadedly connected to the braking electric screw 51, and the braking electric screw 51 is symmetrically rotatably mounted between the end walls of the cavity 70, and the mounting The end of the shaft 24 is fixedly connected to the mounting cylinder 14, and a worm shaft 53 is rotatably connected in the mounting cylinder 14. The worm shaft 53 is dynamically connected to a torsional motor fixedly installed in the lower part of the mounting cylinder 14. A worm 52 is fixedly installed on the outer surface of the worm shaft 53. The worm 52 is meshed with a worm wheel 54. The worm wheel 54 is fixedly mounted on a worm wheel shaft 55. The worm wheel shaft 55 is rotatably mounted on the mounting cylinder 14 and extends to the mounting cylinder 14. The upper end of the worm wheel shaft 55 is fixedly connected to the lower cylinder 12. A stabilizing ring is connected between the mounting cylinder 14 and the lower cylinder 12. During operation, the lower torsion motor is started to drive the worm shaft 53 to rotate, thereby driving the worm 52 to rotate, and the worm 52 is engaged with the worm wheel 54, thereby driving the worm wheel shaft 55 to rotate, thereby driving the lower cylinder 12 to rotate, thereby driving the wellhead connector 11 to rotate and apply a torsional load. The self-locking between the worm 52 and the worm wheel 54 is used to prevent reversal. When a certain angle of inclination test is required, the mounting shaft 24 is driven to rotate a certain angle and then rotated to the corresponding angle, so that the braking electric screw 51 is rotated, thereby driving the braking threaded plates 48 to move closer to each other, thereby driving the meshing braking teeth 49 to move and engage and brake the meshing braking gear 50, thereby fixing the inclination angle.

[0027] Advantageously, the axial loading mechanism includes two groups of fixed blocks 2 symmetrically arranged on the test base plate 1, the two fixed blocks 2 on the same side form a group, and the fixed blocks 2 on the same side are rotatably connected with a connecting shaft 22, and a hydraulic cylinder 3 is fixedly installed on the outer surface of the connecting shaft 22, and a hydraulic rod 18 is slidably connected in the hydraulic cylinder 3, and an articulated shaft 19 is fixedly installed on the upper end of the hydraulic rod 18, and the articulated shaft 19 is hinged in the movable groove 7, and the movable groove 7 is symmetrically arranged at the lower part of the loading frame 8, and an axial braking cavity 69 is provided in the fixed block 2, and an axial loading device is fixedly installed on the outer surface of the connecting shaft 22 in the axial braking cavity 69. The load brake gear 45 is meshed with the axial load brake gear 46, and the axial load brake gear 46 is fixedly mounted on the power end of the axial brake electric push rod 47. The axial brake electric push rod 47 is fixedly mounted on the bottom wall of the axial brake chamber 69. The hydraulic cylinder 3 is provided with an oil filling hole, and the oil filling hole is connected to one end of the oil delivery pipe 4. The other end of the oil delivery pipe 4 is connected to the hydraulic pump 5. The hydraulic pump 5 is fixedly mounted on the oil tank 6. The oil tank 6 is fixedly mounted on the test base plate 1. The hydraulic pump 5 is connected to an extraction pipe 71, and the extraction pipe 71 extends into the oil tank 6; During operation, the hydraulic pump 5 is started to collect the hydraulic oil in the oil tank 6, so that the hydraulic oil in the oil tank 6 enters the oil delivery pipe 4 through the extraction pipe 71 through the hydraulic pump 5, and then enters the hydraulic cylinder 3 through the oil delivery pipe 4, thereby pushing the hydraulic rod 18 to move. By controlling the hydraulic pump 5, the amount of hydraulic oil entering the hydraulic cylinder 3 is controlled, thereby controlling the extension and contraction of the hydraulic rod 18, thereby increasing the axial load. When testing at a certain angle, by controlling the hydraulic pump 5, the hydraulic oil in the oil delivery pipe 4 enters the hydraulic cylinder 3, thereby controlling the extension and contraction of the hydraulic rod 18, thereby increasing the axial load. The pressure pump 5 is used to control the extension degree of the two hydraulic rods 18, so that the hydraulic rod 18 on one side rotates, thereby rotating the hydraulic cylinder 3. After rotating to a certain angle, the axial braking electric push rod 47 is energized, thereby pushing the axial braking electric push rod 47 to engage with the axial loading braking gear 45, braking the connecting shaft 22, thereby fixing the angle, increasing the vertical axial load, and increasing the axial load after tilting at a certain angle, increasing the diversity of the test, and making the test data more complete.

[0028] Advantageously, the upper torsion mechanism includes an upper torsion cavity 64 provided in the loading frame 8, a driving bevel gear shaft 33 is rotatably connected to the end wall of the upper torsion cavity 64, the driving bevel gear shaft 33 is power-connected to the upper torsion motor 34 fixedly installed in the loading frame 8, the end of the driving bevel gear shaft 33 is fixedly connected to a torsion driving bevel gear 32, the torsion driving bevel gear 32 is meshed with a torsion driven bevel gear 31, the torsion driven bevel gear 31 is fixedly installed on the upper end of the upper torsion shaft 20, the upper torsion shaft 20 is rotatably connected to the bottom wall of the upper torsion cavity 64, a flip chute 65 is provided on the end wall of the upper torsion cavity 64, an electric screw 25 is rotatably connected between the end walls of the flip chute 65, the outer surface of the electric screw 25 is threadedly connected to a threaded plate 26, the thread The plate 26 is slidably connected between the end walls of the flip chute 65, and the end of the threaded plate 26 is rotatably connected to the electric rotating shaft 66, and the outer surface of the electric rotating shaft 66 is fixedly connected to the flip plate 27, and the flip plate 27 is rotatably connected to the threaded plate 26. The end of one side of the pawl shaft 29 is rotatably connected to the flip plate 27, and the other end of the pawl shaft 29 is fixedly connected to the pawl 30, and the pawl 30 is meshed with the upper ratchet 35 and the lower ratchet 36. The upper ratchet 35 and the lower ratchet 36 are symmetrically fixedly mounted on the outer surface of the upper torsion shaft 20 on the lower side of the torsion driven bevel gear 31, and the upper ratchet 35 and the lower ratchet 36 have a certain distance. A torsion spring 28 is connected between the pawl 30 and the flip plate 27, and the torsion spring 28 is nested and connected to the outer surface of the pawl shaft 29; During operation, the upper torsion motor 34 is started, thereby driving the driving bevel gear shaft 33 to rotate, thereby driving the driving bevel gear shaft 33 to rotate, thereby driving the torsion driving bevel gear 32 to rotate, and the torsion driving bevel gear 32 is meshed with the torsion driven bevel gear 31, thereby driving the upper torsion shaft 20 to rotate, thereby increasing the torsional load, and the upper torsion shaft 20 rotates, thereby driving the upper ratchet 35 to rotate, and the pawl 30 is meshed with the upper ratchet 35 to limit the reverse rotation of the upper ratchet 35, thereby limiting the reverse rotation of the upper torsion shaft 20, and the torsion spring 28 makes the pawl shaft 29 always meshed with the upper ratchet 35, When a load is applied in the direction of the rotation, the upper torsion motor 34 moves in the opposite direction, causing the electric screw 25 to rotate, thereby driving the threaded plate 26 to move downward, thereby driving the flip plate 27 to move downward, thereby driving the pawl 30 to move downward and disengage from the upper ratchet 35. After disengagement, it drops to a point where the pawl 30 does not collide with the upper ratchet 35 when rotating, causing the electric shaft 66 to rotate, thereby driving the flip plate 27 to rotate one hundred and eighty degrees, thereby causing the pawl 30 to rotate one hundred and eighty degrees, and the electric screw 25 drives the threaded plate 26 to move downward, driving the pawl 30 to engage with the lower ratchet 36, limiting the reverse rotation of the lower ratchet 36.

[0029] Advantageously, the upper clamping mechanism includes an upper cylinder 10 to which the lower end of the upper torsion shaft 20 is fixedly connected, an upper clamping cavity 67 is provided in the upper cylinder 10, an upper driving gear shaft 43 is rotatably connected between the end walls of the upper clamping cavity 67, the upper driving gear shaft 43 is connected to the upper clamping motor power fixedly installed in the upper cylinder 10, an upper driving gear 42 is fixedly connected to the outer surface of the upper driving gear shaft 43, the upper driving gear 42 is meshed with the upper side of the upper annular rack 38, and the upper annular rack 38 is rotatably mounted at the end of the upper clamping cavity 67 Between the walls, the lower side of the upper annular rack 38 is meshedly connected with a plurality of upper driven gears 40, and the upper driven gear 40 is fixedly mounted on the outer surface of the upper clamping screw 41, and the upper clamping screw 41 is rotatably mounted between the end walls of the upper clamping cavity 67, and the outer surface of the upper clamping screw 41 is threadedly connected with an upper threaded barrel 44, and the upper threaded barrel 44 is slidably connected to the end wall of the upper clamping cavity 67 and extends to the inner side of the upper cylinder 10, and the inner end of the upper threaded barrel 44 is fixedly connected with an upper clamping plate 39, and the upper clamping plate 39 is provided with an anti-slip material; During operation, after the upper end of the wellhead connector 11 is inserted into the upper cylinder 10, the upper clamping motor is started, thereby driving the upper driving gear shaft 43 to rotate, thereby driving the upper driving gear 42 to rotate, and the upper driving gear 42 is engaged with the upper annular rack 38, thereby driving the upper annular rack 38 to rotate, and the upper annular rack 38 is engaged with the upper driven gear 40, thereby driving the upper clamping screw 41 to rotate, thereby pushing the upper threaded cylinder 44 to move, thereby pushing the upper clamping plate 39 to move to clamp the upper end position of the wellhead connector 11, and using the locking function of the upper clamping screw 41 to lock it to prevent reverse movement.

[0030] Advantageously, the monitoring mechanism includes an operating console 13 provided on the test base plate 1, the operating console 13 being provided with corresponding control buttons, a display panel integrated on the operating console 13, a control processor provided in the operating console 13, a corresponding control processing program provided in the control processor, a plurality of signal lines connected to the operating console 13, the operating console 13 being connected to a strain gauge 21 via the signal lines, the strain gauge 21 being adhered to the outer surface of the wellhead connector 11 and being used to measure the strain of the wellhead connector 11, the operating console 13 being connected to a monitoring sensor 9 via the signal lines, the monitoring sensor 9 being detachably connected to the outer surface of the wellhead connector 11, a plurality of monitoring sensors 9 being provided and being used to monitor the displacement deformation and pressure received by the wellhead connector 11, and the signal lines being connected to electrical components in the device; During operation, the corresponding button on the operating table 13 is pressed to transmit a signal to the control processor, which is processed by the control processor and sent to the corresponding electrical component to make the corresponding electrical component move, and timely feedback monitoring is performed on the corresponding electrical component, and the information is displayed on the display panel. The strain gauge 21 and the monitoring sensor 9 send the monitored information to the control processor, which is processed by the control processor and displayed on the display panel. The measurement of the axial force and bending moment is measured and calculated through the data fed back by the corresponding components.

[0031] Advantageously, a sealing test mechanism is connected to the lower cylinder 12, and the sealing test mechanism includes a gas channel 89 provided in the lower cylinder 12, a lower elastic sealing gasket 79 is detachably mounted on the inner bottom wall of the lower cylinder 12, the gas channel 89 passes through the inner bottom wall of the lower cylinder 12, and extends to the upper side of the lower elastic sealing gasket 79, a pressure sensor 80 is mounted on the inner bottom wall of the lower cylinder 12 near the column 81, and a ventilation ring is rotatably connected to the end wall of the lower cylinder 12. shaped frame 56, the ventilation annular frame 56 is connected to the gas channel 89, the ventilation annular frame 56 is sealed with the lower cylinder 12, the ventilation annular frame 56 is connected to one end of the gas pipe 17, and is connected to the inside of the ventilation annular frame 56, the other end of the gas pipe 17 is connected to the air pump 16 fixedly mounted on the test base plate 1, a control valve is installed at the outlet position of the gas channel 89 on the bottom wall of the lower cylinder 12, and an upper sealing elastic pad 90 is fixedly mounted on the inner top wall of the upper cylinder 10; During operation, the air pump 16 is started for ventilation, so that the gas enters the ventilation ring frame 56 through the gas pipe 17, and then enters the gas channel 89. The control valve is opened to allow the gas to enter the wellhead connector 11. When the wellhead connector 11 is installed between the upper cylinder 10 and the lower cylinder 12, the upper side is pressed against the upper sealing elastic pad 90, and the lower side is pressed against the lower elastic sealing pad 79. The pressure sensor 80 is located in the wellhead connector 11. The pressure sensor 80 monitors the pressure of the wellhead connector 11. When a certain amount of gas is introduced into the wellhead connector 11, the control valve is closed and the air pump 16 is paused. The pressure sensor 80 monitors the air pressure in the wellhead connector 11 in real time and displays the monitored results on the display panel.

[0032] Advantageously, the lower cylinder 12 is provided with a power socket, through which the entire device is powered. The power socket is connected to a plurality of power transmission wires, which are connected to the electrical components in the device.

[0033] The present invention provides a method for testing a wellhead connector of an underwater Christmas tree under complex loads. The method is based on any of the above-mentioned devices for testing a wellhead connector of an underwater Christmas tree under complex loads, and the steps include: Step 1: Insert the plug into the power socket to power the entire device; Step 2: Place the wellhead connector 11 between the lower cylinder 12 and the upper cylinder 10 to move the axial loading mechanism, thereby clamping the wellhead connector 11 between the lower cylinder 12 and the upper cylinder 10; Step 2: The lower clamping mechanism moves to clamp and support the lower part of the wellhead connector 11 and to support the inner side of the wellhead connector 11 to ensure the reliability of the clamping and prevent slippage; Step 3: The upper clamping mechanism moves to clamp the upper portion of the wellhead connector 11; Step 4: After the clamping is completed, the axial loading mechanism moves to realize the loading of the axial load, and by controlling the extension of the two hydraulic rods 18 differently, the axial load loading test is realized after tilting at a certain angle; Step 5: The upper torsion mechanism moves, thereby applying a unilateral torsion load to the wellhead connector 11. When the torsion load increases in two different directions, the lower torsion mechanism moves in a direction opposite to the direction in which the upper torsion mechanism increases the torsion load, thereby applying torsion loads in two different directions. Step 6: Monitoring the movement of the mechanism to monitor the changes of the wellhead connector 11 under various loads; Step 7: The sealing test mechanism moves, thereby performing a sealing test on the wellhead connector 11 .

[0034] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0035] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A device for testing underwater Christmas tree wellhead connectors under complex loads, characterized by: The invention comprises a test base plate (1), wherein the test base plate (1) is connected to a loading frame (8) via an axial loading mechanism, wherein the axial loading mechanism is used for applying an axial load, wherein the loading frame (8) is connected to an upper torsion mechanism, wherein the upper torsion mechanism is used for providing a torsion load during a test, wherein the lower end of the upper torsion mechanism is connected to an upper clamping mechanism, wherein the upper clamping mechanism is used for clamping the upper end of a wellhead connector (11) under test, wherein a lower torsion mechanism is provided on the test base plate (1), wherein the lower torsion mechanism is used for providing a torsion load during a test, wherein the lower torsion mechanism is connected to a lower clamping mechanism, wherein the lower clamping mechanism is used for clamping the lower end of the wellhead connector (11) under test, and wherein a monitoring mechanism is connected to the test base plate (1), wherein the monitoring mechanism is used for monitoring deformation occurring during a test and an applied load.

2. The underwater Christmas tree wellhead connector testing device under complex loads according to claim 1, characterized in that: The lower clamping mechanism comprises a lower cylinder (12), an annular lower clamping cavity (68) is provided in the lower cylinder (12), a lower driving gear shaft (62) is rotatably connected between the end walls of the lower clamping cavity (68), the lower driving gear shaft (62) is connected to the power of the lower clamping motor fixedly installed in the lower cylinder (12), a lower driving gear (63) is fixedly installed on the lower driving gear shaft (62), the lower driving gear (63) is meshed with the lower part of the lower annular rack (57), the lower annular rack (57) is rotatably installed between the end walls of the lower clamping cavity (68), the upper side of the lower annular rack (57) is meshed with a plurality of lower driven gears (61), the lower driven gears The wheel (61) is fixedly mounted on the outer surface of the lower clamping screw (58), and the lower clamping screw (58) is rotatably mounted between the end walls of the lower clamping cavity (68). The outer surface of the lower clamping screw (58) is threadedly connected to a lower threaded cylinder (60), and the lower threaded cylinder (60) is slidably connected to the end wall of the lower clamping cavity (68) and extends to the inner side of the lower cylinder (12). The end of the lower clamping cavity (68) is fixedly connected to a lower clamping plate (59), and the lower clamping plate (59) clamps the outer surface of the lower end of the wellhead connector (11). The outer surface of the lower clamping plate (59) is provided with an anti-slip material. The outer surface of the lower driving gear shaft (62) is fixedly mounted with a transmission main bevel gear ( 72), the transmission main bevel gear (72) is meshed with the transmission sub-bevel gear (73), the transmission sub-bevel gear (73) is fixedly mounted on the upper end of the transmission bevel gear shaft (74), the transmission bevel gear shaft (74) is rotatably mounted on the bottom wall of the lower clamping cavity (68), and extends into the pulley cavity (75) provided on the lower side of the lower clamping cavity (68), the lower end of the transmission bevel gear shaft (74) is fixedly mounted with a toothed pulley 1 (76), the toothed pulley 1 (76) and the toothed pulley 2 (78) are connected by a toothed belt (77), the toothed pulley 2 (78) is fixedly mounted on the lower end of the pulley shaft (87), the pulley shaft (87) is rotatably mounted on the pulley cavity (75) 5) on the upper end wall and extends into the tightening bevel gear cavity (82) provided in the column (81), the column (81) is fixedly mounted on the inner bottom wall of the lower cylinder (12), the upper end of the pulley shaft (87) is fixedly connected with a tightening active bevel gear (83), a plurality of tightening driven bevel gears (86) are meshedly connected to the tightening active bevel gear (83), the tightening driven bevel gears (86) are arranged along the circumferential direction of the tightening active bevel gear (83), the tightening driven bevel gear (86) is fixedly mounted on the end of a tightening screw rod (88), the tightening screw rod (88) is rotatably mounted on the end wall of the tightening bevel gear cavity (82), and a tightening nut cylinder (85) is threadedly connected to the tightening screw rod (88),The tightening nut tube (85) is slidably connected to the column (81), and the end of the tightening nut tube (85) is fixedly connected to a tightening plate (84). The tightening plate (84) is tightened on the inner side of the lower part of the wellhead connector (11), and the outer surface of the tightening plate (84) is provided with anti-slip material.

3. The device for testing underwater Christmas tree wellhead connectors under complex loads according to claim 2, characterized in that: The lower torsion mechanism comprises a mounting block (15) symmetrically fixedly mounted on the test base plate (1), a cavity (70) is provided in the mounting block (15), a mounting shaft (24) is rotatably connected through the end wall of the cavity (70), an engaging brake gear (50) is fixedly mounted on the outer surface of the mounting shaft (24) in the cavity (70), the engaging brake gear (50) is meshed with the engaging brake teeth (49), the engaging brake teeth (49) are fixedly mounted on the inner surface of the braking thread plate (48), the braking thread plate (48) is threadedly connected to the braking electric screw (51), the braking electric screw (51) is symmetrically rotatably mounted between the end walls of the cavity (70), the mounting shaft (24 ) is fixedly connected to the end thereof with a mounting cylinder (14), a worm shaft (53) is rotatably connected in the mounting cylinder (14), the worm shaft (53) is connected to the torsional motor fixedly installed in the lower part of the mounting cylinder (14), a worm (52) is fixedly installed on the outer surface of the worm shaft (53), the worm (52) is meshed with a worm wheel (54), the worm wheel (54) is fixedly installed on a worm wheel shaft (55), the worm wheel shaft (55) is rotatably installed on the mounting cylinder (14), and extends to the mounting cylinder (14), the upper end of the worm wheel shaft (55) is fixedly connected to the lower cylinder (12), and a stabilizing ring is connected between the mounting cylinder (14) and the lower cylinder (12).

4. The device for testing underwater Christmas tree wellhead connectors under complex loads according to claim 3, characterized in that: The axial loading mechanism comprises two groups of fixed blocks (2) symmetrically arranged on the test base plate (1), the two fixed blocks (2) on the same side form a group, a connecting shaft (22) is rotatably connected between the fixed blocks (2) on the same side, a hydraulic cylinder (3) is fixedly installed on the outer surface of the connecting shaft (22), a hydraulic rod (18) is slidably connected in the hydraulic cylinder (3), a hinge shaft (19) is fixedly installed at the upper end of the hydraulic rod (18), the hinge shaft (19) is hinged in the movable groove (7), the movable groove (7) is symmetrically arranged at the lower part of the loading frame (8), an axial braking cavity (69) is provided in the fixed block (2), and an axial loading braking cavity (69) is fixedly installed on the outer surface of the connecting shaft (22) in the axial braking cavity (69). Gear (45), the axial loading brake gear (45) is meshed with the axial loading brake tooth (46), the axial loading brake tooth (46) is fixedly mounted on the axial brake electric push rod (47) for power connection, the axial brake electric push rod (47) is fixedly mounted on the bottom wall of the axial brake chamber (69), the hydraulic cylinder (3) is provided with an oil filling hole, the oil filling hole is connected to one end of the oil delivery pipe (4), the other end of the oil delivery pipe (4) is connected to the hydraulic pump (5), the hydraulic pump (5) is fixedly mounted on the oil tank (6), the oil tank (6) is fixedly mounted on the test base plate (1), the hydraulic pump (5) is connected to an extraction pipe (71), and the extraction pipe (71) extends into the oil tank (6).

5. The underwater Christmas tree wellhead connector testing device under complex loads according to claim 4, characterized in that: The upper torsion mechanism comprises an upper torsion chamber (64) provided in the loading frame (8), an active bevel gear shaft (33) is rotatably connected to the end wall of the upper torsion chamber (64), the active bevel gear shaft (33) is connected to the upper torsion motor (34) fixedly installed in the loading frame (8), the end of the active bevel gear shaft (33) is fixedly connected to the torsion active bevel gear (32), the torsion active bevel gear (32) is meshed with the torsion driven bevel gear (31), the torsion driven bevel gear (31) is fixedly installed on the upper end of the upper torsion shaft (20), the upper torsion shaft (20) is rotatably connected to the bottom wall of the upper torsion chamber (64), a flip chute (65) is provided on the end wall of the upper torsion chamber (64), an electric screw (25) is rotatably connected between the end walls of the flip chute (65), the outer surface of the electric screw (25) is threadedly connected to a threaded plate (26), and the threaded plate (26) slides The end of the threaded plate (26) is connected to the end wall of the flip chute (65), the end of the threaded plate (26) is rotatably connected to the electric shaft (66), the outer surface of the electric shaft (66) is fixedly connected to the flip plate (27), the flip plate (27) is rotatably connected to the threaded plate (26), the end of one side of the pawl shaft (29) is rotatably connected to the flip plate (27), the end of the other side of the pawl shaft (29) is fixedly connected to the pawl (30), the pawl (30) is connected to the upper ratchet ( The upper ratchet (35) and the lower ratchet (36) are meshed, the upper ratchet (35) and the lower ratchet (36) are symmetrically fixedly mounted on the outer surface of the upper torsion shaft (20) on the lower side of the torsion driven bevel gear (31), and the upper ratchet (35) and the lower ratchet (36) have a certain distance, a torsion spring (28) is connected between the pawl (30) and the flip plate (27), and the torsion spring (28) is nested and connected to the outer surface of the pawl shaft (29).

6. The device for testing underwater Christmas tree wellhead connectors under complex loads according to claim 5, characterized in that: The upper clamping mechanism comprises an upper cylinder (10) fixedly connected to the lower end of the upper torsion shaft (20), an upper clamping cavity (67) is provided in the upper cylinder (10), an upper driving gear shaft (43) is rotatably connected between the end walls of the upper clamping cavity (67), the upper driving gear shaft (43) is connected to the upper clamping motor fixedly installed in the upper cylinder (10), an upper driving gear (42) is fixedly connected to the outer surface of the upper driving gear shaft (43), the upper driving gear (42) is meshed with the upper side of the upper annular rack (38), and the upper annular rack (38) is rotatably installed between the end walls of the upper clamping cavity (67). The lower side of the upper annular rack (38) is meshed with a plurality of upper driven gears (40), and the upper driven gears (40) are fixedly mounted on the outer surface of the upper clamping screw (41). The upper clamping screw (41) is rotatably mounted between the end walls of the upper clamping cavity (67). The outer surface of the upper clamping screw (41) is threadedly connected with an upper threaded barrel (44), and the upper threaded barrel (44) is slidably connected to the end wall of the upper clamping cavity (67) and extends to the inner side of the upper cylinder (10). The inner end of the upper threaded barrel (44) is fixedly connected with an upper clamping plate (39), and the upper clamping plate (39) is provided with an anti-slip material.

7. The device for testing a wellhead connector of an underwater Christmas tree under complex loads according to claim 6, characterized in that: The monitoring mechanism comprises an operating console (13) provided on the test base plate (1), the operating console (13) being provided with corresponding control buttons, a display panel integrated on the operating console (13), a control processor being provided in the operating console (13), a corresponding control processing program being provided in the control processor, a plurality of signal lines being connected to the operating console (13), the operating console (13) being connected to a strain gauge (21) via the signal lines, the strain gauge (21) being adhered to the outer surface of the wellhead connector (11), the operating console (13) being connected to a monitoring sensor (9) via the signal lines, and the monitoring sensor (9) being detachably connected to the outer surface of the wellhead connector (11).

8. The device for testing a wellhead connector of an underwater Christmas tree under complex loads according to claim 7, characterized in that: The lower cylinder (12) is connected to a sealing test mechanism, which includes a gas channel (89) provided in the lower cylinder (12), a lower elastic sealing gasket (79) detachably mounted on the inner bottom wall of the lower cylinder (12), the gas channel (89) passes through the inner bottom wall of the lower cylinder (12) and extends to the upper side of the lower elastic sealing gasket (79), a pressure sensor (80) is mounted on the inner bottom wall of the lower cylinder (12) near the column (81), and the lower cylinder (12) A ventilation annular frame (56) is rotatably connected to the end wall, the ventilation annular frame (56) is communicated with the gas channel (89), the ventilation annular frame (56) and the lower cylinder (12) are sealed, the ventilation annular frame (56) is connected to one end of the gas delivery pipe (17) and is communicated with the inside of the ventilation annular frame (56), the other end of the gas delivery pipe (17) is connected to the air pump (16) fixedly installed on the test base plate (1), and a control valve is installed at the outlet of the gas channel (89) on the bottom wall of the lower cylinder (12).

9. The underwater Christmas tree wellhead connector testing device under complex loads according to claim 8, characterized in that: The lower cylinder (12) is provided with an electrical socket.

10. A method for testing a wellhead connector of an underwater Christmas tree under complex loads, based on the apparatus for testing a wellhead connector of an underwater Christmas tree under complex loads according to any one of claim 9, characterized in that: The steps include: Step 1: Insert the plug into the power socket to power the entire device; Step 2: placing the wellhead connector (11) between the lower cylinder (12) and the upper cylinder (10), so that the axial loading mechanism moves, thereby clamping the wellhead connector (11) between the lower cylinder (12) and the upper cylinder (10); Step 2: The lower clamping mechanism moves, thereby clamping and supporting the lower part of the wellhead connector (11), and supporting the inner side of the wellhead connector (11), ensuring the reliability of the clamping and preventing slippage; Step 3: The upper clamping mechanism moves to clamp the upper portion of the wellhead connector (11); Step 4: After the clamping is completed, the axial loading mechanism moves to realize the loading of the axial load, and by controlling the extension of the two hydraulic rods (18) differently, the loading test of the axial load after tilting at a certain angle is realized; Step 5: The upper torsion mechanism moves, thereby applying a torsion load in a unilateral direction to the wellhead connector (11). When the torsion loads in two different directions are increased, the lower torsion mechanism moves in a direction opposite to the direction in which the torsion load is increased by the upper torsion mechanism, thereby applying torsion loads in two different directions. Step 6: monitoring the movement of the mechanism, thereby monitoring the changes of the wellhead connector (11) under the application of various loads; Step seven: The sealing test mechanism moves, thereby performing a sealing test on the wellhead connector (11).

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