A tensioner for a blowout preventer of a dry wellhead of an offshore drilling

Abstract

The application discloses a kind of marine drilling dry wellhead blowout preventer tensioner, including two tensioning liquid cylinders, chain and energy storage control pry, each tensioning liquid cylinder is connected with blowout preventer group hanging by chain, two tensioning liquid cylinders are communicated with the high-pressure outlet of energy storage control pry by a high-pressure hose respectively, two tensioning liquid cylinders are also communicated with the low-pressure return port of energy storage control pry by a low-pressure hose respectively.The device of the application meets the top tension requirement of blowout preventer for offshore jack-up drilling platform and tension leg platform, and also has high integration degree, good stability, good practicality and popularization value.

Description

Technical Field

[0001] This invention belongs to the technical field of offshore oil drilling equipment, and relates to a blowout preventer tensioning device for dry wellheads in offshore drilling. Background Technology

[0002] Based on the installation location of the wellhead assemblies, offshore drilling wellheads can be divided into two types: surface dry wellheads and subsea wet wellheads. Dry wellheads are installed on the drilling platform and connected to the subsea mudline suspension system via a riser. The blowout preventer (BOP) is located at the top of the riser. These are typically used on jack-up drilling platforms or tension leg platforms. Wet wellheads are installed on the seabed, with the subsea BOP installed on the wellhead and connected to a shunt on the platform via a riser string. These are typically used on floating drilling platforms or drilling vessels. Considering the high cost constraints of deep-sea oil and gas development, jack-up drilling platforms and tension leg platforms, with their lower day costs compared to floating drilling platforms or drilling vessels, will remain the main force in offshore exploration and drilling for a considerable period of time. Existing dry wellhead technology mainly consists of a BOP and a wellhead suspension system, typically installed below the drilling platform. The BOP is installed at the top of the riser string to ensure the safety of drilling operations. An upper section is installed on the upper part of the BOP for connecting the wellhead and the shunt. The riser string located at the bottom of the blowout preventer is mechanically connected to the seabed mudline suspension device at its bottom. Therefore, the riser string should always be under tension to ensure that it is not twisted, crushed, or deformed by its own weight, seawater surge, ocean currents, and tides.

[0003] In actual offshore drilling operations, the design of riser top tension application devices for jack-up drilling platforms and tension leg platforms should consider two factors: 1) Since the platform itself is rigidly fixed to the seabed through permanent or temporary structures, the platform will not experience significant movement. Only the movement of the riser under the influence of seawater needs to be considered. Compared to floating platforms, the riser top tension device for jack-up drilling platforms and tension leg platforms does not require wave compensation during use. Sufficient top tension needs to be applied to the riser to maintain the riser string in a statically stable state. Due to the huge mass of the blowout preventer (BOP), this top tension must also overcome the BOP's own weight; 2) The riser of jack-up drilling platforms and tension leg platforms does not have a riser tensioning ring like that on floating drilling platforms. Top tension can only be applied through the BOP hoisting and shackle installed on the top of the riser; 3) Multiple wellheads on the seabed are not perfectly flat, and there is a certain height difference between each well location. In addition, it is necessary to adapt to different operating water depths. The specific specifications of the riser will result in the BOP installation position not being fixed. In summary, the tensioning device for blowout preventer (BOP) used in dry wellheads for offshore drilling should meet the basic requirements of adjustable tension magnitude, adjustable tension application position, compact structure, and stable reliability. However, there are still significant gaps in the existing technology of related BOP tensioning devices. Summary of the Invention

[0004] The purpose of this invention is to provide a blowout preventer tensioning device for dry wellheads in marine drilling, which solves the problem of poor dynamic stability of the riser system in existing self-elevating drilling platforms and tension leg platforms.

[0005] The technical solution adopted in this invention is a blowout preventer tensioning device for dry wellheads in marine drilling, comprising two tensioning cylinders, a chain, and an energy storage control skid. Each tensioning cylinder is suspended and connected to the blowout preventer assembly via the chain. Each of the two tensioning cylinders is connected to the high-pressure oil outlet of the energy storage control skid via a high-pressure hose. Each of the two tensioning cylinders is also connected to the low-pressure oil return port of the energy storage control skid via a low-pressure hose.

[0006] The blowout preventer tensioning device for dry wellheads in marine drilling of the present invention is further characterized in that:

[0007] The tensioning cylinder has the following structure: an upper lug is welded to the upper part of the cylinder barrel, which is hinged to a mounting ear plate. The mounting ear plate is directly welded and fixed to the bottom crossbeam of the drilling platform. A lower lug is provided at the end of the piston rod, which is hinged to a lifting shackle. The lifting shackle is then hooked to a chain. A spherical bearing is installed in the pin hole of the mounting ear plate. Each tensioning cylinder is also equipped with a cylinder displacement sensor.

[0008] The structure of the energy storage control skid includes a main frame, within which three sets of accumulators and a functional valve block are installed. The liquid and gas ends of the three sets of accumulators are connected in parallel. The liquid ends of the three sets of accumulators are connected to the rod chamber of the tensioning cylinder, and the gas ends of the three sets of accumulators are connected in parallel to an external air inlet. A pressure gauge group consisting of four pressure gauges is installed on the main frame. A control box is also installed on the main frame, and a control panel is installed on the upper surface of the control box.

[0009] The energy storage control skid is equipped with a P oil port, an R oil port, an L oil port, and an external air inlet. The P oil port is a pressure source interface; the R oil port is a return oil port; the L oil port is a drain oil port; and the external air inlet is connected to an external high-pressure air source.

[0010] The P port is internally connected to port 1 of the proportional pressure reducing valve. Port 3 of the proportional pressure reducing valve is connected to port 4 of the three-position four-way solenoid directional valve. Port 6 of the three-position four-way solenoid directional valve is connected to port B of the energy storage control skid. Port 7 of the three-position four-way solenoid directional valve is connected to port 8 of the solenoid cartridge valve. The three liquid terminals (ports 11, 12, and 13) and the three gas terminals (ports 14, 15, and 16) of the accumulator are combined to store energy. After the liquid end of the accumulator is merged, one end is connected to port A of the energy storage control skid, and the other end is connected to port 9 of the solenoid cartridge valve through a pipeline; after the gas end of the accumulator is merged, it is connected to the external air charging port; port 17 of the overflow valve is connected to the merging pipeline of the liquid ends of the three accumulators, port 18 of the overflow valve is merged with port 5 of the three-position four-way solenoid directional valve and then connected to port R; port 10 of the solenoid cartridge valve and port 2 of the proportional pressure reducing valve are merged and then connected to port L.

[0011] The control panel includes a power indicator light, a system start / stop switch, an emergency stop switch, a system status switching switch, a pressure / stroke adjustment switch, a tension adjustment knob, and a cylinder displacement indicator. The system start / stop switch controls the energization and de-energization of the entire tensioning device; when the system is energized, the power indicator light turns green. The emergency stop switch cuts off the system power in emergencies. The system status switching switch controls the solenoid cartridge valve, the pressure / stroke adjustment switch controls the three-position four-way solenoid directional valve, and the tension adjustment knob controls the proportional pressure reducing valve to set the maximum system tension. The cylinder displacement indicator is a bar-type indicator.

[0012] The beneficial effects of this invention are that, through innovative structural design and control method development, a direct-acting hydraulic cylinder is designed to apply tension to the top of the water-tightening guide tube. The unique hydraulic system design allows for arbitrary adjustment of the top tension and application position, meeting the operating conditions of jack-up drilling platforms and tension leg platforms. This includes the following aspects:

[0013] 1) Excellent Reliability: The hydraulic cylinder is directly connected to the blowout preventer (BOP) via a chain, and tension application and adjustment are achieved through the hydraulic system. The introduction of the accumulator ensures that minor leaks do not affect the tension, resulting in excellent system reliability provided the hydraulic system is well maintained. 2) High Safety: The hydraulic cylinder is welded to the platform structure, significantly increasing its load-bearing capacity. The use of explosion-proof valves on the pipelines prevents tension loss and hydraulic damage caused by hose ruptures. Real-time monitoring of the cylinder position and system pressure provides alerts for position alarms, pressure loss, and other failures. 3) Convenient Operation and Maintenance: The hydraulic cylinder and BOP are connected by a chain with shackle-type connections for easy disassembly and position adjustment. System tension can be adjusted hydraulically according to operational needs without releasing nitrogen. 4) High System Integration: The energy storage device, control valve assembly, and control panel are integrated, effectively reducing the equipment's footprint and facilitating installation, transportation, and maintenance. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the device of the present invention;

[0015] Figure 2a This is a schematic diagram of the tensioning cylinder in the device of the present invention; Figure 2b yes Figure 2a A schematic diagram of the side section;

[0016] Figure 3a This is a schematic diagram of the energy storage control skid in the device of the present invention; Figure 3b yes Figure 3a A side view diagram; Figure 3c yes Figure 3a A top-down view;

[0017] Figure 4 This is a block diagram of the electro-hydraulic control connection in the device of the present invention;

[0018] Figure 5 This is a schematic diagram of the control panel layout in the device of the present invention.

[0019] In the diagram, 1. Waterproof conduit string, 2. Blowout preventer assembly, 3. Chain, 4. Tensioning cylinder, 5. High-pressure hose, 6. Low-pressure hose, 7. Conduit stub, 8. Chuck, 9. Energy storage control skid, 10. Pipeline explosion-proof valve, 11. Cylinder displacement sensor;

[0020] 4.1. Cylinder barrel, 4.2. Piston rod, 4.3 Upper lug, 4.4. Pin, 4.5. Mounting lug, 4.6. Lower lug, 4.7. Lifting shackle, 4.8. Shackle fastener, 4.9. Spherical bearing, 4.10. Rib plate, 4.11. Anti-loosening screw;

[0021] 9.1. Accumulator; 9.2. Pressure gauge assembly; 9.3. Control box; 9.4. Main frame; 9.5. Control panel; 9.6. Functional valve block;

[0022] 9.5.1 Power indicator light; 9.5.2 System start / stop switch; 9.5.3 Emergency stop switch; 9.5.4 System status switching switch; 9.5.5 Pressure / stroke adjustment switch; 9.5.6 Tension adjustment knob; 9.5.7 Cylinder displacement indicator.

[0023] 9.6.1. Relief valve; 9.6.2. Solenoid cartridge valve; 9.6.3. Three-position four-way solenoid directional valve; 9.6.4. Proportional pressure reducing valve; 9.6.5. Check valve. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0025] The tensioning device of this invention is mainly installed in conjunction with the lower part of the drilling deck of jack-up drilling platforms and tension leg platforms.

[0026] Reference Figure 1 The overall structure of the tensioning device of the present invention includes two tensioning cylinders 4, a chain 3, and an energy storage control skid 9. Each tensioning cylinder 4 is suspended and connected to the blowout preventer assembly 2 via the chain 3. The lower part of the blowout preventer assembly 2 is connected to the top of the water-resistant conduit string 1. Figure 4 (abbreviated as "BOP+waterproof guide tube"), the upper part of the blowout preventer assembly 2 is connected to the guide tube stub 7, the upper part of the guide tube stub 7 is driven and connected to the chuck 8, the two tensioning cylinders 4 are each connected to the high pressure oil outlet of the energy storage control skid 9 through a high pressure hose 5, and the two tensioning cylinders 4 are also each connected to the low pressure oil return port of the energy storage control skid 9 through a low pressure hose 6, so as to realize the synchronous hydraulic control of the two tensioning cylinders 4;

[0027] Each tensioning cylinder 4 has an internal cavity divided into a rod chamber and a rodless chamber. Because it needs to withstand tensile loads for extended periods, the rod chamber of the tensioning cylinder 4 serves as the working chamber, with a high internal pressure during normal operation. The rodless chamber of the tensioning cylinder 4 serves as the non-working chamber, with no internal pressure during normal operation and only a small pressure when adjusting the cylinder stroke. To maintain the flexibility of the tensioning device, the rod chamber of the tensioning cylinder 4 is connected to a high-pressure hose 5, and the rodless chamber is connected to a low-pressure hose 6. The high-pressure hose 5 and the low-pressure hose 6 are connected to the energy storage control skid 9 after merging. Corresponding to the oil port; the tensioning cylinder 4 is installed with the rod cavity facing downwards, and the blowout preventer assembly 2 and the tensioning cylinder 4 are connected by the chain 3 using a shackle method, thus forming a complete flexible connection blowout preventer tensioning form. Since the guide tube section 7 does not bear the load, the weight of the blowout preventer assembly 2 and the top tension of the water-proof guide tube string 1 are mainly borne by the two tensioning cylinders 4. Due to the shackle function of the chain 3, the length of the chain 3 can be adjusted arbitrarily, and the stroke of the tensioning cylinder 4 can also be adjusted arbitrarily, which can adapt to a wider range of blowout preventer installation positions.

[0028] The tensioning device of this invention uses electro-hydraulic control to adjust tension and stroke. The tensioning cylinder 4 and the energy storage control skid 9 are the main components of the electro-hydraulic control. The energy storage control skid 9, as the core equipment for realizing the tensioning function control, uses a hydraulic power source on the drilling platform for fluid supply. The energy storage control skid 9 integrates an accumulator, control valve, control box, operation panel, etc., enabling local control.

[0029] Reference Figure 2a , Figure 2b The tensioning cylinder 4 has the following structure: an upper lug 4.3 is welded to the upper part of the cylinder barrel 4.1. The upper lug 4.3 is a double lug structure and is hinged to the mounting ear plate 4.5 via a pin 4.4. The mounting ear plate 4.5 is directly welded and fixed to the bottom crossbeam of the drill table. A lower lug 4.6 is provided at the end of the piston rod 4.2. The lower lug 4.6 is hinged to the lifting shackle 4.7 via a shackle fastener 4.8 (a set of bolts and nuts). The lifting shackle 4.7 is then hooked to the chain 3. The pin hole of the mounting ear plate 4.5 is equipped with relevant... The spherical plain bearing 4.9, in conjunction with the pin 4.4, enables the tensioning cylinder 4 to rotate around the pin 4.4 at large axial angles and small radial angles, increasing the degree of freedom of the tensioning cylinder 4 and improving the reliability of the system. The mounting ear plate 4.5 is fixedly connected to the bottom crossbeam of the drill table by welding, and stiffening plates 4.10 are arranged on both sides to improve the structural strength and stability of the mounting ear plate 4.5. Anti-loosening screws 4.11 are installed between the upper ear ring 4.3 and the pin 4.4 to prevent the pin 4.4 from coming loose. See also... Figure 4 Each tensioning cylinder 4 is also equipped with a cylinder displacement sensor 11. Figure 4 (abbreviated as LPT in Chinese).

[0030] Reference Figure 3a , Figure 3b , Figure 3c The structure of the energy storage control skid 9 includes a main frame 9.4, which is constructed from I-beams, square steel pipes, and steel plates. It undergoes anti-corrosion treatment to meet marine environmental requirements. Related components are reliably connected via cables and pipelines, forming a highly integrated unit. Within the main frame 9.4, three sets of 80L accumulators 9.1 and functional valve blocks 9.6 are installed. The liquid and gas ends of the three sets of accumulators 9.1 are connected in parallel. The liquid ends of the three sets of accumulators 9.1 are connected to the rod chamber of the tensioning cylinder 4, and the gas ends of the three sets of accumulators 9.1 are connected in parallel to the external air inlet. A pressure gauge group 9.2 is installed on the main frame 9.4, consisting of four pressure gauges displaying their respective pressure values. A control box 9.3 is also installed on the main frame 9.4, with a control panel 9.5 on its upper surface. This control panel 9.5 is used to collect system data and execute operator commands.

[0031] Accumulator 9.1 is connected to tension cylinder 4 via pipeline. Accumulator 9.1 is usually in the form of multiple sets connected in parallel. Its function is to keep the tensioning device at a constant tension. The total volume of accumulator 9.1 is determined by the allowable tension fluctuation corresponding to the upper and lower limit strokes of the tensioning device. The pre-charge pressure P0 at the air end of accumulator 9.1 is determined by the platform configuration and operating conditions.

[0032] The functional valve block 9.6 integrates the relief valve 9.6.1, the solenoid cartridge valve 9.6.2, the three-position four-way solenoid directional valve 9.6.3, the proportional relief valve 9.6.4, and the check valve 9.6.5, reducing the internal piping of the energy storage control skid 9 and improving the reliability of the system.

[0033] The energy storage control skid 9 integrates energy storage components, hydraulic components, and electrical control components using a steel main frame 9.4. The installation of the external interface of the device can be completed simply by connecting the platform's hydraulic source and power supply to the energy storage control skid 9. The energy storage control skid 9 also features a control box 9.3, a control panel 9.5, and a pressure gauge group 9.2, which makes it convenient to read system status data and simple and reliable to operate.

[0034] Reference Figure 4 The energy storage control skid 9 is equipped with P oil port, R oil port, L oil port and an external air port. P oil port is a pressure source interface, responsible for providing hydraulic power to the tensioning device; R oil port is the oil return port; L oil port is the oil drain port, which is directly connected to the hydraulic oil tank; the external air port is connected to an external high-pressure air source.

[0035] The electromagnetic cartridge valve 9.6.2 is used to switch the tensioning device between normal operating mode and adjustment mode. Internally, it consists of a cartridge valve body, an electromagnetic directional valve, and a shuttle valve. When the electromagnet inside the electromagnetic cartridge valve 9.6.2 is energized, it is in adjustment mode, where the tensioning device's extension, retraction, and tension adjustment functions are performed. When the electromagnet inside the electromagnetic cartridge valve 9.6.2 is de-energized, it is in normal operating mode, and the pressure and stroke in the rod chamber of the tensioning cylinder 4 remain constant.

[0036] An external hydraulic power source enters the proportional relief valve 9.6.4 through port P and then flows to other components, changing the current value entering the proportional relief valve 9.6.4 to make the hydraulic pressure entering the tensioning device adjustable. During tension adjustment, the maximum pressure value P1 of the rod chamber of the tensioning cylinder 4 should vary between the pre-charge pressure P0 of the accumulator 9.1 and the maximum working pressure P2. The maximum tension of the tensioning device is set through the proportional relief valve 9.6.4.

[0037] The three-position four-way solenoid directional valve 9.6.3 is used to regulate the system tension and stroke. 1) When the internal electromagnet of the solenoid cartridge valve 9.6.2 is energized, the left-position electromagnet of the three-position four-way solenoid directional valve 9.6.3 is energized, and the external hydraulic source supplies oil to the rod chamber of the tensioning cylinder 4. When the tensioning device is not under load, the tensioning cylinder 4 will slowly retract, and the oil in the rodless chamber will return. When the tensioning device is under load, and the output pressure of the proportional relief valve 9.6.4 is greater than the liquid end pressure of the accumulator 9.1, 1) Accumulator 9.1 will continuously pressurize, increasing the tension of the tensioning device; 2) When the electromagnet inside the solenoid cartridge valve 9.6.2 is energized, the right-position electromagnet of the three-position four-way solenoid directional valve 9.6.3 is energized, and the external hydraulic source will supply oil to the rodless chamber of the tensioning cylinder 4. When the tensioning device is not under load, the tensioning cylinder 4 will slowly extend, and the oil in the accumulator 9.1 and the rod chamber will return; when the tensioning device is under load, jogging control should be performed to slowly reduce the pressure inside the accumulator 9.1, and the tension of the tensioning device will decrease.

[0038] The relief valve 9.6.1 is used to prevent system overpressure and protect system safety;

[0039] When the tensioning device is working normally, the attitude of the water-proof guide tube string 1 changes suddenly due to the sudden change in sea state, causing the tensioning device to stretch outward rapidly and causing the tensioning cylinder 4 to have a "vacuuming" effect. The one-way valve 9.6.5 located on the return oil line can effectively prevent the cylinder from "vacuuming" by properly sucking oil.

[0040] Because the tensioning cylinder 4 is continuously under tension during operation, its rod chamber contains high-pressure liquid for a long time. The rod chamber is connected to the liquid end of the accumulator 9.1 in the energy storage control skid 9 via a high-pressure hose 5. The accumulator 9.1 provides continuous and stable pressure to the rod chamber of the tensioning cylinder 4. If any section of the high-pressure hose 5 ruptures, the tensioning device will experience an instantaneous halving of tension. Simultaneously, the accumulator 9.1 will rapidly discharge hydraulic oil through the ruptured hose, causing a drop in system pressure. The entire tensioning device will then be unable to provide tension to the blowout preventer assembly 2, potentially leading to accidents such as the blowout preventer assembly 2 falling and colliding, or the water-resistant conduit string 1 being crushed. Therefore, the present invention prevents hose rupture accidents by installing a pipeline explosion-proof valve 10 at each end of each high-pressure hose 5 of the tensioning cylinder 4 (a total of four pipeline explosion-proof valves 10, see...). Figure 4 The pipeline explosion-proof valve 10 is a pressure-triggered type. When the high-pressure hose 5 ruptures and causes oil to flow rapidly through the pipeline explosion-proof valve 10, the hydraulic pressure automatically shuts off the fluid passage after detecting that the pressure difference between the two ends of the pipeline explosion-proof valve 10 exceeds the preset value. The pressure on the rod chamber side of the tensioning cylinder 4 is maintained and the oil on the accumulator 9.1 side does not flow out, thereby achieving safety protection when the high-pressure hose 5 ruptures.

[0041] Reference Figure 4The energy storage control skid 9 is supplied with hydraulic fluid via an external platform hydraulic source. After the high-pressure oil enters the P port, it is connected to the #1 port of the proportional pressure reducing valve 9.6.4. The #3 port of the proportional pressure reducing valve 9.6.4 is connected to the #4 port of the three-position four-way solenoid directional valve 9.6.3. The #6 port of the three-position four-way solenoid directional valve 9.6.3 is connected to the B port of the energy storage control skid 9. The #7 port of the three-position four-way solenoid directional valve 9.6.3 is connected to the #8 port of the solenoid cartridge valve 9.6.2. By controlling the opening and closing of the left and right solenoids of the three-position four-way solenoid directional valve 9.6.3, the oil flows from the #4 port to the #6 or #7 port. The solenoid cartridge valve 9.6.2 is used to control the opening and closing of the #8 and #9 ports, thereby realizing the function of closing the oil circuit when power is lost and opening the oil circuit when power is restored. The three liquid terminals (11#, 12#, and 13#) and gas terminals (14#, 15#, and 16#) of accumulator 9.1 are combined. After the liquid terminals of accumulator 9.1 are combined, one end is connected to port A of the energy storage control skid 9, and the other end is connected to port 9# of the solenoid cartridge valve 9.6.2 via a pipeline. After the gas terminals of accumulator 9.1 are combined, they are connected to an external gas charging port for easy charging of the accumulator. The 17# oil port of the overflow valve 9.6.1 is connected to the merging pipeline of the liquid ends of the three accumulators 9.1 to limit the maximum pressure of the system. The 18# oil port of the overflow valve 9.6.1 merges with the 5# oil port of the three-position four-way solenoid directional valve 9.6.3 and then connects to the R oil port to realize oil return. The 10# oil port of the solenoid cartridge valve 9.6.2 and the 2# port of the proportional pressure reducing valve 9.6.4 merge and then connect to the L oil port to realize oil discharge. In addition, the four pressure gauges S1, S2, S3 and S4 are collectively referred to as pressure gauge group 9.2. They are connected to the corresponding pressure measurement points through pipelines and display the pressures as follows: platform liquid supply pressure, pressure reducing valve outlet pressure, liquid cylinder internal pressure and accumulator gas end pressure.

[0042] Reference Figure 5The control panel 9.5 is equipped with corresponding indicator lights, knobs, switches, and bar graph indicators, providing a clear visual representation of the system status. This includes a power indicator light 9.5.1, a system start / stop switch 9.5.2, an emergency stop switch 9.5.3, a system status switching switch 9.5.4, a pressure / stroke adjustment switch 9.5.5, a tension adjustment knob 9.5.6, and a cylinder displacement indicator 9.5.7. The system start / stop switch 9.5.2 controls the power on and off of the entire tensioning device; when the system is powered on, the power indicator light 9.5.1 will turn green. The emergency stop switch 9.5.3 is used to cut off the system power in emergencies to ensure system safety. The system status indicator is also included. The switching switch 9.5.4 controls the solenoid cartridge valve 9.6.2; the pressure / stroke adjustment switch 9.5.5 controls the three-position four-way solenoid directional valve 9.6.3; and the tension adjustment knob 9.5.6 controls the proportional pressure reducing valve 9.6.4 to set the maximum tension of the system. The system status switching switch 9.5.4, pressure / stroke adjustment switch 9.5.5, and tension adjustment knob 9.5.6 correspond to the control of three electromagnets in the functional valve block 9.6, employing point-to-point control for high reliability and simple maintenance. The cylinder displacement indicator 9.5.7 is a bar graph indicator that collects data from each tensioning cylinder 4 (two tensioning cylinders 4 at...). Figure 5 The signals from the displacement sensors 11 corresponding to the cylinders (abbreviated as cylinder #1 and cylinder #2 respectively) are scaled proportionally and then used to indicate the stroke of each tensioning cylinder 4 in the form of a beam height.

Claims

1. A blowout preventer tensioner for a marine drilling dry wellhead, characterized by: It comprises two tensioning hydraulic cylinders (4), a chain (3) and an energy storage control pry (9), each tensioning hydraulic cylinder (4) is hung and connected with the blowout preventer group (2) through the chain (3), the two tensioning hydraulic cylinders (4) are respectively communicated with the high-pressure oil outlet of the energy storage control pry (9) through a high-pressure hose (5), and the two tensioning hydraulic cylinders (4) are respectively communicated with the low-pressure oil return port of the energy storage control pry (9) through a low-pressure hose (6); The structure of the energy storage control pry (9) is that a main frame (9.4) is arranged, three groups of accumulators (9.1) and a function valve block (9.6) are arranged in the space of the main frame (9.4), the liquid end and the gas end of the three groups of accumulators (9.1) are respectively connected in parallel, the liquid end of the three groups of accumulators (9.1) is connected with the rod cavity of the tensioning hydraulic cylinder (4) after being connected in parallel, and the gas end of the three groups of accumulators (9.1) is communicated with the external air charging port after being connected in parallel; a pressure gauge group (9.2) is installed on the main frame (9.4), the pressure gauge group (9.2) comprises four pressure gauges; a control box (9.3) is further arranged on the main frame (9.4), and a control panel (9.5) is arranged on the upper surface of the control box (9.3); The energy storage control pry (9) is provided with a P oil port, an R oil port, an L oil port and an external air charging port, the P oil port is a pressure source interface, the R oil port is an oil return port, the L oil port is a drain port, and the external air charging port is communicated with an external high-pressure gas source; the P oil port is connected to the 1# oil port of the proportional pressure reducing valve (9.6.4) internally, the 3# oil port of the proportional pressure reducing valve (9.6.4) is communicated with the 4# oil port of the three-position four-way electromagnetic reversing valve (9.6.3), the 6# oil port of the three-position four-way electromagnetic reversing valve (9.6.3) is communicated with the B oil port of the energy storage control pry (9), the 7# oil port of the three-position four-way electromagnetic reversing valve (9.6.3) is communicated with the 8# oil port of the electromagnetic cartridge valve (9.6.2), the three liquid ends 11#, 12# and 13# oil ports and the three gas ends 14#, 15# and 16# gas ports of the accumulator (9.1) are respectively combined, one end of the liquid end of the accumulator (9.1) after being combined is communicated with the A oil port of the energy storage control pry (9), and the other end is connected with the 9# oil port of the electromagnetic cartridge valve (9.6.2) through a pipeline; the gas end of the accumulator (9.1) after being combined is connected with the external air charging port; the 17# oil port of the overflow valve (9.6.1) is connected with the combined pipeline of the liquid end of the three accumulators (9.1), the 18# oil port of the overflow valve (9.6.1) is combined with the 5# oil port of the three-position four-way electromagnetic reversing valve (9.6.3) after being combined and is communicated with the R oil port, and the 10# oil port of the electromagnetic cartridge valve (9.6.2) and the 2# oil port of the proportional pressure reducing valve (9.6.4) are combined and communicated with the L oil port.

2. The blowout preventer tensioner for dry wellheads of offshore drilling rigs according to claim 1, characterized in that: The structure of the tension hydraulic cylinder (4) is that an upper ear ring (4.3) is welded on the upper part of the cylinder barrel (4.1), the upper ear ring (4.3) is hinged with a mounting ear plate (4.5), the mounting ear plate (4.5) is directly welded and fixed on the bottom beam of the drilling floor surface, a lower ear ring (4.6) is arranged at the end of the piston rod (4.2), the lower ear ring (4.6) is hinged with a hoisting and unloading buckle (4.7), the hoisting and unloading buckle (4.7) is connected with a chain (3) in a hooking manner, a pin hole of the mounting ear plate (4.5) is provided with a joint bearing (4.9), and each tension hydraulic cylinder (4) is further provided with a hydraulic cylinder displacement sensor (11).

3. The marine well-drilling rig dry tree preventer tensioner of claim 1, wherein: The control panel (9.5) comprises a power-on indicator lamp (9.5.1) 9.5.1), a system start / stop switch (9.5.2), an emergency stop switch (9.5.3), a system state toggle switch (9.5.4), a pressure / stroke adjustment switch (9.5.5), a tension adjustment knob (9.5.6), a fluid cylinder displacement indicator (9.5.7); wherein, The system start-stop switch (9.5.2) is used for controlling the power-on and power-off of the whole tensioning device, the power-on indicator lamp (9.5.1) will become green after the system is powered on, the emergency stop switch (9.5.3) is used for cutting off the power supply of the system in an emergency, the system state switching switch (9.5.4) is used for controlling the electromagnetic plug-in valve (9.6.2), the pressure / stroke adjustment switch (9.5.5) is used for controlling the three-position four-way electromagnetic reversing valve (9.6.3), the tension adjustment knob (9.5.6) is used for controlling the proportional pressure reducing valve (9.6.4) to realize the setting of the maximum tension of the system, and the hydraulic cylinder displacement indicator (9.5.7) is a light column type indicator.

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