A durable and stable ultra-high pressure wellhead device

Abstract

This invention relates to the field of oil and gas extraction equipment technology, specifically disclosing a durable and stable ultra-high pressure wellhead device, including a tubing head four-way connector, a production tree, connecting components, and auxiliary components. Resonance is avoided by installing pressure-type vibrating fittings in the production tree and combining them with a vibration monitoring and adjustment system; a multi-layer composite sealing structure and double-layer sealing rings are used to improve sealing performance; a reinforced support structure and an anti-slip structure are used to ensure stability; and a smart monitoring and control system enables real-time monitoring, early warning, and remote control. This invention effectively solves many problems of existing wellhead devices in ultra-high pressure environments, significantly improving the stability, sealing performance, and intelligence of the device, reducing maintenance costs, and improving oil and gas extraction efficiency and safety. It is suitable for various ultra-high pressure oil and gas extraction scenarios.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction equipment technology, specifically to a long-lasting and stable ultra-high pressure wellhead device. Background Technology

[0002] Against the backdrop of continuously growing global energy demand, the development of deep, ultra-high pressure oil and gas fields is becoming increasingly crucial. my country is rich in deep oil and gas resources; however, traditional wellhead equipment has revealed many problems when facing ultra-high pressure environments.

[0003] From a pressure-bearing perspective, conventional 140MPa equipment experiences a sharp decline in sealing performance under high pressure, making it highly susceptible to leakage and even, in extreme cases, rupture, seriously threatening production safety and efficiency. Internationally, these imported equipment are not only extremely expensive, with a single wellhead costing tens of millions of dollars, but also have long maintenance cycles, sometimes lasting several months, significantly increasing extraction costs and production risks.

[0004] In terms of structural design, existing wellhead equipment lacks optimization for complex operating conditions such as high pressure and high sulfur content. On the one hand, critical components such as mechanical connections, mechanical seals, and wellhead wall fixation points are prone to irreversible damage due to resonance under the impact of high-pressure media. For example, low-pressure wellhead media have low flow velocity and a small range of parameter variations, while high-pressure wellhead media exhibit significantly different velocity, vibration, and impurity levels, making traditional wellhead equipment difficult to adapt to. On the other hand, traditional support structures and connection methods cannot provide sufficient stability and reliability under ultra-high pressure, easily leading to problems such as component loosening and detachment.

[0005] Sealing technology is also a major challenge. Traditional sealing materials, such as rubber, struggle to maintain good sealing performance over long periods in harsh environments with ultra-high pressure, high temperature, and high sulfur content, leading to an increased risk of leakage. Furthermore, traditional sealing structures, such as flange connections, are prone to leakage due to corrosion; statistics show that traditional flange connections have a relatively high leakage probability.

[0006] In conclusion, it is urgent to develop a wellhead device that can adapt to ultra-high pressure environments and has long-term stability. This is of great significance for improving my country's oil and gas extraction efficiency, reducing costs, and ensuring energy security. Summary of the Invention

[0007] To solve the above problems, the present invention adopts the following technical solution.

[0008] A long-lasting and stable ultra-high voltage wellhead device, comprising:

[0009] The tubing head is a four-way connector, with a tubing connector at the top for connecting the tubing and a bottom for connecting to the well pipe.

[0010] The oil and gas tree is installed above the tubing head four-way and connected to the tubing head four-way via a connecting component;

[0011] A pressure-type vibrating pipe fitting is installed in the oil and gas tree and consists of a rigid connecting pipe and a flexible connecting pipe located inside it. There is an adjustment space between the outer wall of the flexible connecting pipe and the inner wall of the rigid connecting pipe. A pressure adjustment module is connected to the rigid connecting pipe and the pressure adjustment module is in communication with the adjustment space.

[0012] A ranging sensor is installed on the rigid connection pipe, with its detection end located within the adjustment space, and is used to detect the vibration generated by the medium flowing through the pressure-type vibrating pipe fitting.

[0013] The first pressure sensor is mounted on the oil pipe connector;

[0014] A second pressure sensor is installed on the rigid connection pipe;

[0015] The adjustment component is a distributed cavity structure, including an internal cavity distributed circumferentially along the four-way valve of the tubing head and symmetrical cavities on both sides of the production gas tree;

[0016] An adjustment module is connected to the adjustment component and forms a loop;

[0017] The controller is electrically connected to the ranging sensor, the first pressure sensor, the second pressure sensor, the pressure adjustment module, and the adjustment module, and is used to drive the pressure adjustment module and the adjustment module to work based on the detection data.

[0018] The connection between the tubing head four-way and the oil and gas tree adopts a multi-layer composite sealing structure. The inner layer is a sealing ring made of tungsten carbide powder sintered at 1200-1300℃, with a trapezoidal cross-section. The outer layer is a sealing element composed of PEEK polyetheretherketone and an ELG non-magnetic alloy skeleton, wherein the ELG non-magnetic alloy skeleton is annular, and the PEEK polyetheretherketone layer wraps around the skeleton with a lip-shaped cross-section.

[0019] A double-layer sealing ring is provided at each connecting flange. The double-layer sealing ring includes an inner ring with a rectangular cross-section, an outer ring with an L-shaped cross-section, and an elastic sealing protrusion located between the two. The inner ring is made of nitrile rubber. The outer ring is made of fluororubber. The elastic sealing protrusion is a hollow structure and is made of hydrogenated nitrile rubber.

[0020] Preferably, a temperature sensor and a flow sensor are also integrated, which are electrically connected to the controller.

[0021] Preferably, the device is equipped with an ROV control panel for remote operation.

[0022] Preferably, the pressure adjustment module includes a liquid storage tank, a high-pressure plunger pump, an electromagnetic reversing valve, and a pressure transmitter. The liquid storage tank is connected to the high-pressure plunger pump through a high-pressure oil pipe. The outlet of the high-pressure plunger pump is connected to the adjustment space through the electromagnetic reversing valve. The detection end of the pressure transmitter extends into the adjustment space and is electrically connected to the controller to form a pressure closed-loop control.

[0023] Preferably, the regulating module includes a variable vane pump, a proportional relief valve, and an electric ball valve. The variable vane pump is connected to the regulating assembly via a high-pressure hose and the electric ball valve. The proportional relief valve is connected in parallel to the outlet end of the variable vane pump. The cavity wall of the regulating assembly is made of 42CrMo alloy steel with chrome plating on the inner wall and a one-way valve at the bottom.

[0024] Preferably, the controller communicates with the pressure adjustment module and the regulating module via industrial Ethernet to ensure real-time transmission and analysis of vibration and pressure parameters.

[0025] Preferably, when the controller calculates the target natural frequency adjustment value, it uses the formula f_target = f_target, based on the vibration frequency, external disturbance frequency, pressure difference, and vibration amplitude parameters. 当前 +Δf 基础 +Δf 压力 Perform the calculation, where: f 目标 f is the natural frequency of the target. 当前 Given the current natural frequency, Δf 基础 The basic adjustment is set at 8Hz when the external disturbance frequency deviates from the current natural frequency by ≤5Hz, and at 5Hz when the deviation is 5-10Hz. Δf 压力 For pressure correction, Δf 压力 =0.2×ΔP, where ΔP is the pressure difference in MPa, and a 2Hz safety margin is added when the vibration amplitude exceeds the limit; the controller (10) calculates the value of the difference between the target frequency and the current frequency using the formula V=V 总 ×(Δf / f 当前 The required medium injection volume is calculated as V × k, where V is the medium injection volume. 总 Let f be the total volume of the cavity, and Δf be the difference between the target frequency and the current frequency, where Δf = f 目标 -f 当前 The unit is Hz, f 当前 k is the current inherent frequency. 容积 This is a volume correction factor, ranging from 1.2 to 1.5, which is dynamically adjusted according to the viscosity of the medium.

[0026] A control method for a persistently stable ultra-high voltage wellhead device includes the following steps:

[0027] Data acquisition: The vibration frequency f0 and vibration amplitude A0 of the flexible connection pipeline are continuously collected by the ranging sensor; the pressure difference ΔP=P1-P2 is collected by the first and second pressure sensors; and environmental parameters are collected by the temperature sensor and flow sensor.

[0028] Resonance detection: The controller calculates the current natural frequency fcurrent. When the deviation between the external disturbance frequency f and the current natural frequency fcurrent is ≤5Hz, the frequency adjustment mechanism is triggered; when the vibration amplitude A0 > 0.15mm, the pressure adjustment mechanism is triggered.

[0029] Pressure regulation: The controller starts the high-pressure plunger pump, and the solenoid directional valve switches to the oil injection position to inject hydraulic oil into the adjustment space until the vibration amplitude A0 ≤ 0.15mm; if the pressure exceeds the set upper limit, the solenoid directional valve switches to the oil return position to relieve pressure;

[0030] Frequency regulation: The controller calculates the target frequency f and the medium injection volume V, starts the variable vane pump, and the electric ball valve opens the corresponding cavity passage to inject the medium into the regulating component until the natural frequency reaches the target f; when it is necessary to reduce stiffness, the proportional relief valve is controlled to relieve pressure and return oil.

[0031] Remote monitoring: The ROV control panel displays the equipment's operating parameters in real time, receives warning signals from the controller, and allows for remote operation.

[0032] Compared with the prior art, the beneficial effects of this invention are as follows:

[0033] This invention's multi-layer composite sealing structure achieves rigid sealing under high pressure through an inner tungsten carbide sealing ring, whose trapezoidal cross-section design increases the contact area. The outer PEEK-ELG alloy seal utilizes the temperature resistance of PEEK and the elastic compensation capability of ELG alloy; the lip interference fit can adapt to pressure fluctuations, and its corrosion resistance in high-sulfur environments is superior to traditional nitrile rubber. The hollow elastic protrusion (made of hydrogenated nitrile rubber) of the double-layer sealing ring at the connecting flange can absorb pressure shocks, maintaining seal integrity even under pressure fluctuations.

[0034] The pressure adjustment module and the regulating component of this invention form an anti-resonance system. The pressure adjustment module uses PWM speed regulation of a high-pressure plunger pump and a solenoid reversing valve for rapid response. By adjusting the spatial pressure, the stiffness of the flexible connection pipe changes dynamically, directly suppressing high-frequency vibration. The regulating component changes the overall stiffness through distributed cavity medium injection and works with a proportional overflow valve to stabilize the pressure, achieving precise adjustment based on the inherent frequency and effectively avoiding the resonant frequency.

[0035] The regulating component cavity of this invention is made of 42CrMo alloy steel, and the inner wall is chrome-plated to reduce the friction coefficient of the medium flow and reduce energy loss; the one-way valve uses a hard alloy valve core to improve its erosion resistance life. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0037] Figure 2 This is a cross-sectional view of the overall structure of the present invention;

[0038] Figure 3 for Figure 2 A partial structural diagram at point A in the middle;

[0039] Figure 4 This is a schematic diagram of the connection structure of the pressure adjustment module of the present invention;

[0040] Figure 5 This is a cross-sectional view of the multi-layer composite seal of the present invention;

[0041] Figure 6 This is a cross-sectional view of the double-layer sealing ring of the present invention.

[0042] In the diagram: 1. Tubing head four-way connector; 2. Oil and gas tree; 3. Connecting assembly; 11. Tubing connector; 5. Pressure vibrating fitting; 20. Pressure adjustment module; 30. Adjustment assembly; 40. Adjustment module; 501. Rigid connecting pipe; 502. Flexible connecting pipe; 503. Adjustment space; 504. Distance sensor; 201. Liquid storage tank; 202. High-pressure plunger pump. Detailed Implementation

[0043] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0044] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. Example

[0046] like Figure 1-6 As shown in this embodiment, a long-lasting and stable ultra-high pressure wellhead device includes an oil tubing head four-way 1, an oil and gas tree 2, a pressure-type vibrating pipe fitting 5, a distance measuring sensor 504, a first pressure sensor 6, a second pressure sensor 7, an adjustment component 30, an adjustment module 40, a pressure adjustment module 20, and a controller.

[0047] Tubing head tee 1: The top is equipped with a tubing connector 11 for connecting the tubing, and the bottom can be connected to the pipeline inside the well. It is the basic load-bearing component of the wellhead equipment.

[0048] Oil and gas tree 2: Installed above the oil pipe head four-way 1, and connected to the oil pipe head four-way 1 through the connecting component 3, used to control the flow of media during the oil and gas extraction process.

[0049] Pressure-type vibration fitting 5: installed in the oil and gas tree 2, consisting of a rigid connecting pipe 501 and an internal flexible connecting pipe 502. An adjustment space 503 is formed between the outer wall of the flexible connecting pipe 502 and the inner wall of the rigid connecting pipe 501. A pressure adjustment module 20 is connected to the rigid connecting pipe 501. The pressure adjustment module 20 is connected to the adjustment space 503 and can suppress vibration by changing the pressure in the adjustment space 503.

[0050] The sensor assembly includes a distance sensor 504, a first pressure sensor 6, and a second pressure sensor 7, and also integrates a temperature sensor and a flow sensor. The distance sensor 504 is mounted on the rigid connecting pipe 501, with its detection end located within the adjustment space 503, and is used to detect vibrations generated by the flow of the medium. The first pressure sensor 6 is mounted on the oil pipe connector 11, and the second pressure sensor 7 is mounted on the rigid connecting pipe 501, used to collect pressure difference data. Each sensor is electrically connected to the controller, transmitting monitoring data in real time.

[0051] Adjustment component 30 and adjustment module 40: The adjustment component 30 is a distributed cavity structure, including four built-in cavities 301 (each with a volume of 1.2-1.5L) distributed circumferentially along the four-way valve 1 of the oil pipe head, and two symmetrical cavities 302 (each with a volume of 0.8-1L) on both sides of the oil and gas tree 2. The cavity walls are made of 42CrMo alloy steel (tensile strength ≥1080MPa), with chrome plating on the inner walls (thickness 0.05-0.1mm), and a one-way valve (pressure rating 42MPa) is provided at the bottom. The adjustment module 40 includes a variable vane pump 401, a proportional relief valve 402, and an electric ball valve 403. The variable vane pump 401 is connected to the adjustment component 30 via a high-pressure hose 404 and the electric ball valve 403. The proportional relief valve 402 is connected in parallel to the outlet end of the variable vane pump 401 and is used to adjust the inherent frequency of the device.

[0052] Pressure adjustment module 20 includes a liquid storage tank 201 (316L stainless steel, volume 5-8L), a high-pressure plunger pump 202 (maximum output pressure 35MPa, PWM speed regulation), an electromagnetic reversing valve 203 (two-position four-way type, response time ≤50ms), and a pressure transmitter 204 (measuring range 0-40MPa, accuracy ±0.5%FS). The liquid storage tank 201 is connected to the high-pressure plunger pump 202 through a high-pressure oil pipe 205. The outlet of the high-pressure plunger pump 202 is connected to the adjustment space 503 through the electromagnetic reversing valve 203. The detection end of the pressure transmitter 204 extends into the adjustment space 503 and is electrically connected to the controller to form a pressure closed-loop control.

[0053] Controller and remote control: The controller adopts an industrial-grade PLC (processor frequency ≥1GHz), and communicates with the ranging sensor 504, each pressure sensor 6, 7, pressure adjustment module 20, and adjustment module 40 via industrial Ethernet (speed ≥100Mbps), with a data sampling frequency of 1kHz; it is equipped with an ROV control panel (supporting Ethernet / fiber optic communication), which supports remote parameter setting, status monitoring, and emergency operation.

[0054] Sealing Structure: The connection between the oil pipe head four-way 1 and the oil and gas tree 2 adopts a multi-layer composite sealing structure a. The inner layer is a sealing ring a1 made of tungsten carbide powder sintered at 1200-1300℃, and the sealing ring a1 has a trapezoidal cross section. The outer layer is a PEEK-ELG alloy sealing element a2. The connecting flange is equipped with a double sealing ring b (inner ring b1 nitrile rubber, outer ring b2 fluororubber) and an elastic protrusion b3 to ensure ultra-high pressure sealing.

[0055] In this embodiment, ELG nonmagnetic alloy is a general abbreviation for Elgiloy® alloy, a registered trademark alloy product of Elgiloy Specialty Metals, Inc. in the United States. ELG nonmagnetic alloy is a high-performance cobalt-based austenitic alloy designed for extreme working conditions. In the fields of energy and marine engineering, it is mainly used in oil and gas downhole tools, valve components in acidic oil and gas fields, and elastic elements in deep-sea engineering equipment. Its core advantage lies in its combined advantages of resistance to sulfide corrosion, resistance to seawater erosion, nonmagnetism, and high elasticity.

[0056] The working principle of this embodiment is as follows: a long-lasting and stable ultra-high pressure wellhead device, including a tubing head four-way 1, a production gas tree 2, a pressure-type vibration pipe fitting 5, a distance measuring sensor 504, a first pressure sensor 6, a second pressure sensor 7, an adjustment component 30, an adjustment module 40, a pressure adjustment module 20, and a controller.

[0057] Tubing head tee 1: The top is equipped with a tubing connector 11 for connecting the tubing, and the bottom can be connected to the pipeline inside the well. It is the basic load-bearing component of the wellhead equipment.

[0058] Oil and gas tree 2: Installed above the oil pipe head four-way 1, and connected to the oil pipe head four-way 1 through the connecting component 3, used to control the flow of media during the oil and gas extraction process.

[0059] Pressure-type vibration fitting 5: installed in the oil and gas tree 2, consisting of a rigid connecting pipe 501 and an internal flexible connecting pipe 502. An adjustment space 503 is formed between the outer wall of the flexible connecting pipe 502 and the inner wall of the rigid connecting pipe 501. A pressure adjustment module 20 is connected to the rigid connecting pipe 501. The pressure adjustment module 20 is connected to the adjustment space 503 and can suppress vibration by changing the pressure in the adjustment space 503.

[0060] The sensor assembly includes a distance sensor 504, a first pressure sensor 6, and a second pressure sensor 7, and also integrates a temperature sensor and a flow sensor. The distance sensor 504 is mounted on the rigid connecting pipe 501, with its detection end located within the adjustment space 503, and is used to detect vibrations generated by the flow of the medium. The first pressure sensor 6 is mounted on the oil pipe connector 11, and the second pressure sensor 7 is mounted on the rigid connecting pipe 501, used to collect pressure difference data. Each sensor is electrically connected to the controller, transmitting monitoring data in real time.

[0061] Adjustment component 30 and adjustment module 40: The adjustment component 30 is a distributed cavity structure, including four built-in cavities 301 (each with a volume of 1.2-1.5L) distributed circumferentially along the four-way valve 1 of the oil pipe head, and two symmetrical cavities 302 (each with a volume of 0.8-1L) on both sides of the oil and gas tree 2. The cavity walls are made of 42CrMo alloy steel (tensile strength ≥1080MPa), with chrome plating on the inner walls (thickness 0.05-0.1mm), and a one-way valve (pressure rating 42MPa) is provided at the bottom. The adjustment module 40 includes a variable vane pump 401, a proportional relief valve 402, and an electric ball valve 403. The variable vane pump 401 is connected to the adjustment component 30 via a high-pressure hose 404 and the electric ball valve 403. The proportional relief valve 402 is connected in parallel to the outlet end of the variable vane pump 401 and is used to adjust the inherent frequency of the device.

[0062] Pressure adjustment module 20 includes a liquid storage tank 201 (316L stainless steel, volume 5-8L), a high-pressure plunger pump 202 (maximum output pressure 35MPa, PWM speed regulation), an electromagnetic reversing valve 203 (two-position four-way type, response time ≤50ms), and a pressure transmitter 204 (measuring range 0-40MPa, accuracy ±0.5%FS). The liquid storage tank 201 is connected to the high-pressure plunger pump 202 through a high-pressure oil pipe 205. The outlet of the high-pressure plunger pump 202 is connected to the adjustment space 503 through the electromagnetic reversing valve 203. The detection end of the pressure transmitter 204 extends into the adjustment space 503 and is electrically connected to the controller to form a pressure closed-loop control.

[0063] Controller and remote control: The controller adopts an industrial-grade PLC (processor frequency ≥1GHz), and communicates with the ranging sensor 504, each pressure sensor 6, 7, pressure adjustment module 20, and adjustment module 40 via industrial Ethernet (speed ≥100Mbps), with a data sampling frequency of 1kHz; it is equipped with an ROV control panel (supporting Ethernet / fiber optic communication), which supports remote parameter setting, status monitoring, and emergency operation.

[0064] Sealing structure: The connection between the oil pipe head four-way 1 and the oil and gas tree 2 adopts a multi-layer composite sealing structure a, the inner layer is a metal tungsten carbide sealing ring a1 (sintered at 1200-1300℃, trapezoidal cross section), and the outer layer is a PEEK-ELG alloy sealing element a2; the connecting flange is equipped with a double-layer sealing ring b (inner ring b1 nitrile rubber, outer ring b2 fluororubber) and an elastic protrusion b3 to ensure ultra-high pressure sealing.

[0065] Each sensor collects parameters such as vibration frequency, amplitude, pressure difference, temperature, and flow rate in real time, and transmits them to the controller via industrial Ethernet at a rate of ≥100Mbps. The sampling frequency reaches 1kHz to ensure real-time data transmission.

[0066] The principle of resonance judgment and adjustment is that the controller, based on the vibration frequency, external disturbance frequency, pressure difference, and vibration amplitude parameters, uses the formula f 目标 =f 当前 +Δf 基础 The target natural frequency is calculated using the +Δf pressure. When the external disturbance frequency deviates from the current natural frequency by ≤5Hz, a frequency adjustment mechanism is triggered: the adjustment module 40 starts the variable vane pump 401, injecting the medium into the built-in cavity 301 and symmetrical cavity 302 of the adjustment component 30 through the electric ball valve 403, changing the overall stiffness of the device and causing the natural frequency to deviate from the resonance range; when the deviation is 5-10Hz, the corresponding basic adjustment amount is used, and when the vibration amplitude exceeds the limit, a safety margin of 2Hz is added.

[0067] The principle of pressure closed-loop control is as follows: when the vibration amplitude is greater than 0.15 mm, the controller drives the pressure adjustment module 20 to work: the high-pressure plunger pump 202 injects hydraulic oil into the adjustment space 503 through the solenoid directional valve 203, and the pressure transmitter 204 provides real-time feedback of pressure data to form closed-loop control until the vibration amplitude drops to a safe range; when the pressure exceeds the set upper limit, the solenoid directional valve 203 switches to the return oil position to relieve pressure.

[0068] The principle of remote monitoring and operation is that the controller displays the equipment operating parameters in real time through the ROV control panel, supports remote control of valve opening and closing, parameter adjustment and other operations, and realizes unmanned operation.

[0069] Here are two application scenarios:

[0070] Scene 1

[0071] It is applied to a 175MPa ultra-high pressure oil and gas field in western my country. The sulfur content of the medium in this area is 3000ppm, and the ambient temperature ranges from -10 to 80℃. It is necessary to solve the problems of high pressure sealing, sulfur corrosion and medium flow resonance.

[0072] Technical Solution Application Details

[0073] Sealing Structure Installation: A multi-layer composite sealing structure a is installed at the connection between the oil pipe head four-way 1 and the oil and gas tree 2. The inner layer is a sealing ring a1 made of tungsten carbide powder sintered at 1250℃, with cross-sectional dimensions of 10mm at the top, 18mm at the bottom, and 12mm in height. High-temperature anti-sulfur grease (temperature resistance 200℃) is applied during installation. The outer layer, PEEK-ELG alloy seal a2, has an ELG alloy skeleton thickness of 4mm and a PEEK lip interference of 0.8mm. The sealing surface is compacted by flange bolts (preload torque 800N·m). At the connecting flange, the eight hollow elastic protrusions b3 (4mm in height) between the inner ring b1 (nitrile rubber, Shore hardness 65HA, thickness 6mm) and the outer ring b2 (fluororubber, Shore hardness 75HA, thickness 10mm) of the double-layer sealing ring b are evenly stressed to ensure a tight seal.

[0074] Core module configuration:

[0075] The pressure adjustment module 20 includes: a 6L reservoir 201 storing ISOVG46 anti-wear hydraulic oil (3% anti-sulfur additive content); a high-pressure plunger pump 202 with a set flow rate of 0.5-5L / min and PWM speed control accuracy of ±0.1L / min; a two-position four-way electromagnetic reversing valve 203 with a response time of 45ms; and a pressure transmitter 204 with a measurement range of 0-40MPa, providing real-time feedback of the pressure in the adjustment space 503.

[0076] The regulating component 30 and regulating module 40 are as follows: the built-in cavity 301 of the oil pipe head four-way 1 (single volume 1.3L), the symmetrical cavity 302 of the oil and gas tree 2 (single volume 0.9L), the cavity wall is made of 42CrMo steel with chrome plating (thickness 0.08mm); the variable vane pump 401 of the regulating module 40 has a maximum pressure of 25MPa, the proportional relief valve 402 has a set pressure of 10-20MPa, and the electric ball valve 403 has a nominal diameter of DN25, ensuring that the medium injection rate is adjustable from 0-2L / min.

[0077] The controller and communication: adopts Siemens S7-1200 PLC (main frequency 1.2GHz), with an industrial Ethernet communication rate of 100Mbps between the ranging sensor 504 and each module, a sampling frequency of 1kHz, and a built-in frequency correction algorithm for sulfur-resistant environments (temperature compensation coefficient -0.02Hz / ℃).

[0078] Operation process and technical solution verification:

[0079] Data acquisition phase: The ranging sensor 504 (accuracy ±0.01mm) monitors the vibration of the flexible connecting pipe 502 in real time. The first pressure sensor 6 and the second pressure sensor 7 collect ΔP=8MPa. The temperature sensor reports the medium temperature of 75℃. The data is transmitted to the controller via Ethernet with a delay of ≤10ms.

[0080] Resonance adjustment implementation: When the frequency of medium flow disturbance (28Hz) deviates from the device's current natural frequency (30Hz) by 2Hz (≤5Hz), the controller activates the adjustment module 40: the electric ball valve 403 opens the passage of the left symmetrical cavity 302 of the oil and gas tree 2, and the variable vane pump 401 injects hydraulic oil at a flow rate of 1.5L / min. By changing the volume of the medium in the cavity (injection volume 0.6L, accounting for 67% of the cavity volume), the stiffness of the oil and gas tree 2 is increased by 22%, and the natural frequency rises from 30Hz to 40Hz (calculated value 39.6Hz), with a measured deviation ≤0.5Hz.

[0081] Pressure control response: When the vibration amplitude reaches 0.18 mm (exceeding the threshold of 0.15 mm), the controller drives the pressure adjustment module 20 to work: the high-pressure plunger pump 202 injects hydraulic oil into the adjustment space 503 through the electromagnetic reversing valve 203, and the pressure in the adjustment space is increased from 15 MPa to 22 MPa within 3 seconds. The pressure transmitter 204 provides real-time feedback data. Under closed-loop control, the vibration amplitude is stably reduced to 0.12 mm, and the pressure fluctuation is ≤ ±0.3 MPa.

[0082] Application effects: Long-lasting seal, good fatigue resistance, prevents component breakage, and reduces maintenance costs.

[0083] Scene 2

[0084] It is applied to a deep-sea oil and gas field in the South China Sea with a water depth of 2000 meters, a wellhead pressure of 200MPa, an ambient temperature of 5℃, and a seawater salinity of 35‰. It is necessary to solve the problems of high-pressure sealing, increased viscosity of low-temperature medium, and remote control.

[0085] Technical Solution Application Details

[0086] Underwater adaptation design:

[0087] Sealing Enhancement: A multi-layer composite sealing structure is used. The outer PEEK-ELG alloy seal is layered. A fluororubber waterproof layer (2mm thick) is added, tightly bonded to the seal body through vulcanization, enhancing underwater impermeability. The double-layer sealing ring at the connecting flange uses hydrogenated nitrile rubber (seawater immersion life ≥5 years). The number of elastic protrusions (b) is increased to 8 (uniformly distributed circumferentially), with each protrusion having a cross-sectional size of 3mm × 5mm, ensuring a sealing surface specific pressure ≥35MPa under a seawater static pressure of 20MPa. The connection between the tubing head tee 1 and the well pipe uses a special API6ALC thread, combined with underwater-specific sealant (seawater corrosion resistance grade ISO12944-5C5-M). The threaded connection torque is controlled at 1200-1500 N·m, and the thread engagement length is ≥30mm.

[0088] Low-temperature medium adaptation: The reservoir 201 of the pressure adjustment module 20 has a volume of 8L and stores low-temperature anti-wear hydraulic oil (viscosity index VI≥140, kinematic viscosity ≤1000mm² / s at -20℃). 3% low-temperature flow improver is added to the oil. The outer walls of the built-in cavity 301 and symmetrical cavity 302 of the adjustment component 30 are wrapped with an electric heating device (power 50W / m). A temperature sensor is equipped to monitor the cavity temperature in real time. The cavity medium temperature is maintained at 15-20℃ through closed-loop control of the controller to avoid the sudden increase in low-temperature viscosity from affecting the adjustment response.

[0089] Core module deep-sea configuration:

[0090] Pressure adjustment module 20: High-pressure plunger pump 202 has a maximum output pressure of 35MPa, and the PWM speed regulation algorithm is optimized for low temperature environment (speed regulation accuracy ±0.2L / min). The motor adopts a deep-sea waterproof motor (protection level IP68); the electromagnetic reversing valve 203 is selected as an underwater salt spray resistant model (salt spray test ≥1000h), with a response time of 48ms; the pressure transmitter 204 is equipped with a titanium alloy protective shell (thickness 2mm), which is resistant to seawater corrosion rate <0.005mm / year and has a measurement accuracy of ±0.3%FS.

[0091] The regulating assembly 30 and regulating module 40 consist of four built-in cavities 301 (each with a volume of 1.5L) for the oil pipe head four-way 1 and two symmetrical cavities 302 (each with a volume of 1L) for the oil and gas tree 2, with a total cavity volume of 7L. The cavity walls are made of 42CrMo alloy steel, heat-treated (hardness 28-32HRC), with an inner wall chrome plating thickness of 0.1mm and a surface roughness Ra≤0.8μm. The variable vane pump 401 of the regulating module 40 is equipped with a heater (heating power 100W) at its outlet and a temperature relay (operating temperature 25℃) to ensure stable medium viscosity. The proportional relief valve 402 has a set pressure of 5-20MPa, and the pressure fluctuation is controlled within ±0.5MPa at low temperatures. The electric ball valve 403 uses an underwater actuator (protection level IP68), has a nominal diameter of DN25, an opening and closing time ≤1s, and a valve body made of 316L stainless steel.

[0092] Controller and Remote Communication: The controller uses a Schneider M340 PLC (1GHz main frequency) and integrates a deep-sea dedicated anti-interference module (electromagnetic compatibility level EN61000-6-2); it communicates with the ranging sensor 504, pressure sensors 6 and 7, and each module via fiber optic Ethernet (speed 100Mbps), and the cable is armored deep-sea optical cable (tensile strength ≥10kN, bending radius ≥20D); the ROV control panel is equipped with a 21.5-inch sunlight-visible touch screen, supports hydraulic / electric dual-mode operation, and uses the MODBUS TCP / IP communication protocol with a data transmission delay ≤500ms.

[0093] Operation process and technical solution verification:

[0094] Data acquisition phase: Distance sensor 504 (accuracy ±0.01mm, underwater protection level IP68) monitors the vibration of flexible connecting pipe 502 in real time, with a sampling frequency of 1kHz; first pressure sensor 6 and second pressure sensor 7 collect ΔP=10MPa, temperature sensor reports medium temperature of 8℃, and the data is transmitted to the surface controller via optical fiber.

[0095] Resonance adjustment implementation: The current disturbance frequency of 1Hz deviates from the current natural frequency of 0.7Hz by 0.3Hz (≤5Hz). The controller starts the adjustment algorithm: calculate the target frequency f_target = 0.7 + 8 + 0.2 × 10 = 10.7Hz, consider the low temperature viscosity correction (k_volume = 1.5), and inject the medium into the built-in cavity 301 of the four-way valve 1 of the oil pipe head and the symmetrical cavity 302 of the oil and gas tree 2 through the adjustment module 40. The injection volume V = 7 × (10 / 0.7) × 1.5 ≈ 150L (injected in 3 times). Within 15s, the natural frequency of the device is raised to 11Hz to avoid the current resonance range.

[0096] Pressure control response: When the low temperature causes the vibration amplitude of the flexible connection pipe 502 to reach 0.17mm (exceeding the threshold of 0.15mm), the controller drives the pressure adjustment module 20 to work: the electromagnetic reversing valve 203 switches to the oil injection position, the high-pressure plunger pump 202 injects oil into the adjustment space 503 at a flow rate of 2L / min, the pressure transmitter 204 provides real-time feedback of pressure data, and the pressure of the adjustment space 503 is increased from 18MPa to 25MPa within 5s, the vibration amplitude is reduced to 0.11mm, and the pressure control accuracy is ±0.4MPa.

[0097] Remote control verification: After setting the adjustment parameters remotely via the ROV control panel and sending the "cavity depressurization" command, the proportional relief valve 402 responded within 800ms, and the pressure in the symmetrical cavity 302 dropped from 20MPa to 5MPa. There was no data loss during the entire operation, verifying the reliability of the remote control.

[0098] The above are merely preferred embodiments of the present invention; however, the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and its improved concept, should be covered within the scope of protection of the present invention.

Claims

1. A long-lasting and stable ultra-high pressure wellhead device, characterized in that, include: The tubing head tee (1) has a tubing connector (11) at the top for connecting the tubing and can be connected to the pipeline in the well at the bottom; The oil and gas tree (2) is installed above the oil pipe head four-way (1) and connected to the oil pipe head four-way (1) through the connecting component (3); A pressure-type vibrating pipe fitting (5) is installed in the oil and gas tree (2) and consists of a rigid connecting pipe (501) and a flexible connecting pipe (502) located inside it. There is an adjustment space (503) between the outer wall of the flexible connecting pipe (502) and the inner wall of the rigid connecting pipe (501). A pressure adjustment module (20) is connected to the rigid connecting pipe (501) and the pressure adjustment module (20) is connected to the adjustment space (503). The distance sensor (504) is installed on the rigid connection pipe (501), with the detection end located in the adjustment space (503), and is used to detect the vibration generated by the medium flowing through the pressure vibrating pipe (5); The first pressure sensor (6) is mounted on the oil pipe connector (11); A second pressure sensor (7) is installed on the rigid connection pipe (501); The regulating component (30) is a distributed cavity structure, including an internal cavity (301) distributed circumferentially along the oil pipe head four-way (1) and symmetrical cavities (302) on both sides of the oil and gas tree (2). The adjustment module (40) is connected to the adjustment component (30) and forms a loop; The controller is electrically connected to the ranging sensor (504), the first pressure sensor (6), the second pressure sensor (7), the pressure adjustment module (20), and the adjustment module (40), and is used to drive the pressure adjustment module (20) and the adjustment module (40) to work according to the detection data. The connection between the tubing head four-way (1) and the oil and gas tree (2) adopts a multi-layer composite sealing structure. The inner layer is a sealing ring made of tungsten carbide powder sintered at 1200-1300℃, and the sealing ring has a trapezoidal cross-section. The outer layer is a sealing element composed of PEEK polyether ether ketone and ELG non-magnetic alloy skeleton, wherein the ELG non-magnetic alloy skeleton is annular, and the PEEK polyether ether ketone layer wraps the skeleton and has a lip-shaped cross-section. A double-layer sealing ring is provided at each connecting flange. The double-layer sealing ring includes an inner ring with a rectangular cross-section, an outer ring with an L-shaped cross-section, and an elastic sealing protrusion located between the two. The inner ring is made of nitrile rubber, the outer ring is made of fluororubber, and the elastic sealing protrusion is a hollow structure made of hydrogenated nitrile rubber.

2. The long-term stable ultra-high voltage wellhead device according to claim 1, characterized in that: It also integrates a temperature sensor and a flow sensor, which are electrically connected to the controller.

3. The long-term stable ultra-high voltage wellhead device according to claim 1, characterized in that: The pressure adjustment module (20) includes a liquid storage tank (201), a high-pressure plunger pump (202), an electromagnetic reversing valve (203), and a pressure transmitter (204). The liquid storage tank (201) is connected to the high-pressure plunger pump (202) through a high-pressure oil pipe (205). The outlet of the high-pressure plunger pump (202) is connected to the adjustment space (503) through the electromagnetic reversing valve (203). The detection end of the pressure transmitter (204) extends into the adjustment space (503) and is electrically connected to the controller to form a pressure closed-loop control.

4. The long-term stable ultra-high voltage wellhead device according to claim 1, characterized in that: The regulating module (40) includes a variable vane pump (401), a proportional relief valve (402), and an electric ball valve (403). The variable vane pump (401) is connected to the regulating component (30) via a high-pressure hose (404) and the electric ball valve (403). The proportional relief valve (402) is connected in parallel to the outlet end of the variable vane pump (401). The cavity wall of the regulating component (30) is made of 42CrMo alloy steel, with chrome plating on the inner wall, and a one-way valve is provided at the bottom.

5. The long-term stable ultra-high voltage wellhead device according to claim 1, characterized in that: The controller communicates with the pressure adjustment module (20) and the adjustment module (40) via industrial Ethernet to ensure real-time transmission and analysis of vibration and pressure parameters.

6. The long-term stable ultra-high voltage wellhead device according to claim 1, characterized in that: When calculating the target natural frequency adjustment value, the controller uses the vibration frequency, external disturbance frequency, pressure difference, and vibration amplitude parameters, and employs the formula f. 目标 =f 当前 +Δf 基础 +Δf 压力 Perform the calculation, where: f 目标 f is the natural frequency of the target. 当前 Given the current natural frequency, Δf 基础 The basic adjustment is set at 8Hz when the external disturbance frequency deviates from the current natural frequency by ≤5Hz, and at 5Hz when the deviation is 5-10Hz. Δf 压力 For pressure correction, Δf 压力 =0.2×ΔP, where ΔP is the pressure difference in MPa, and a 2Hz safety margin is added when the vibration amplitude exceeds the limit; the controller calculates the value based on the difference between the target frequency and the current frequency using the formula V=V 总 ×(Δf / f 当前 )×k 容积 Calculate the required media injection volume, where: V is the media injection volume (L), V 总 Let f be the total volume of the cavity, and Δf be the difference between the target frequency and the current frequency, where Δf = f 目标 -f 当前 The unit is Hz, f 当前 k is the current inherent frequency. 容积 This is a volume correction factor, ranging from 1.2 to 1.5, which is dynamically adjusted according to the viscosity of the medium.

7. A control method for a persistently stable ultra-high pressure wellhead device, applied to the device described in any one of claims 1-6, characterized in that, Includes the following steps: Data acquisition: The vibration frequency f0 and vibration amplitude A0 of the flexible connecting pipe (502) are continuously acquired by the distance sensor (504), the pressure difference ΔP=P1-P2 is acquired by the first pressure sensor (6) and the second pressure sensor (7), and environmental parameters are acquired by the temperature sensor and the flow sensor. Resonance determination: The controller calculates the current natural frequency f. 当前 When the external disturbance frequency f is different from the current natural frequency f 当前 When the deviation is ≤5Hz, the frequency adjustment mechanism is triggered; when the vibration amplitude A0>0.15mm, the pressure adjustment mechanism is triggered. Pressure regulation: The controller starts the high-pressure plunger pump (202), and the solenoid directional valve (203) switches to the oil injection position to inject hydraulic oil into the adjustment space (503) until the vibration amplitude A0 ≤ 0.15mm; if the pressure exceeds the set upper limit, the solenoid directional valve switches to the oil return position to relieve pressure; Frequency regulation: The controller calculates the target frequency f and the medium injection volume V, starts the variable vane pump (401), and the electric ball valve (403) opens the corresponding cavity passage, injecting the medium into the regulating component (30) until the natural frequency reaches f. 目标 When stiffness needs to be reduced, control the proportional relief valve (402) to relieve pressure and return oil; Remote monitoring: The ROV control panel displays the equipment's operating parameters in real time, receives warning signals from the controller, and allows for remote operation.

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