Control system and control method for sea pipe replacement and well killing under emergency working condition of offshore unmanned platform

Abstract

The invention relates to the field of unmanned and intelligent control of an offshore unmanned oil and gas production platform, and discloses a control system and a control method for sea pipeline replacement and well killing under emergency working conditions of an offshore unmanned platform, and the control system comprises an input layer and a control core layer, the control core layer comprises a state sensing module which is used for collecting main power, emergency power, sea-land communication and process monitoring signals; the emergency decision module judges whether the platform enters a replacement or well killing process or not according to the monitoring signal, and automatically selects a corresponding execution strategy to enter the execution control module; the execution control module is used for controlling a valve execution mechanism, a diesel oil well killing pump, a high-voltage circuit breaker, a seawater lifting pump, a fire pump and diesel oil replacement pump equipment to realize replacement and well killing operation in sequence; the safety protection module provides fire interlocking, overpressure alarm and replacement failure protection functions while executing operation of the control module; the execution layer controls a physical execution mechanism to act according to the control core layer; the output layer is used for providing operation results and state feedback of the control system.

Description

Technical Field

[0001] This invention relates to the field of unmanned and intelligent control technology for offshore unmanned oil and gas production platforms, and in particular to a control system and control method for pipeline replacement and well control in emergency operating conditions of offshore unmanned platforms. Background Technology

[0002] When offshore high-pour-point oilfields are shut down under planned conditions or due to accidents, if pipeline sweeping / replacement and well control cannot be completed in a timely manner, there is a risk of crude oil solidification, wax deposition, or hydrates, which can lead to pipeline blockage, well instability, and a significant extension of the oilfield shutdown time.

[0003] Traditional solutions rely on the coordination of on-site personnel and central control system, emergency power and sea-land communication, which have the following drawbacks: (1) There is a lack of personnel on-site for unmanned platforms and offshore facilities, and the waiting time for boarding is long; (2) The duration of emergency replacement and well control often exceeds the battery life of conventional UPS; (3) When sea-land communication is lost, remote manual replacement / well control cannot be carried out; (4) After the multi-platform / sea-land coordination is shut down, it is still necessary to perform long-term sequential logic control on key valves and pumps.

[0004] Therefore, there is an urgent need for a dedicated control system that can still operate autonomously under conditions of minimal power supply or even communication interruption. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide a control system and method for subsea pipeline replacement and well control in emergency situations of unmanned offshore platforms. Under emergency conditions such as lack of main power, lack of emergency power, and loss of communication between sea and land, the system enables autonomous execution of one-click subsea pipeline replacement and well control operations through independent power supply and timing logic, while ensuring fire and gas safety, interlock integrity, and minimum power load.

[0006] To achieve the above objectives, in a first aspect, the technical solution adopted by the present invention is as follows: a control system for emergency pipeline replacement and well control of an unmanned offshore platform, comprising: an input layer, including operating condition trigger signals and on-site monitoring data; a control core layer, including: a status perception module, used to collect main power, emergency power, sea-land communication and process monitoring signals, wherein the monitoring signals include pressure, flow rate, valve status and well status; an emergency decision module, which determines whether the platform enters the replacement or well control process based on the monitoring signals, and automatically selects the corresponding execution strategy and enters the execution control module; an execution control module, which controls the valve actuator, diesel well control pump, high-voltage circuit breaker, seawater lift pump, fire pump and diesel replacement pump equipment to sequentially realize replacement and well control operations; a safety protection module, which provides fire interlock, overpressure alarm and replacement failure protection functions while the execution control module is running, to ensure the operational safety of the unmanned platform under extreme conditions; an execution layer, which is the physical execution mechanism of the control system, controlling the action of the physical execution mechanism according to the control core layer; and an output layer, used to provide the operating results and status feedback of the control system.

[0007] Furthermore, it includes an independent UPS power supply unit; the independent UPS power supply unit is physically isolated from the original PCS / ESD / FGS system power supply of the platform, and has power diagnosis and low-voltage switching strategies.

[0008] Furthermore, the execution control module adopts a 1:1 redundant architecture of controller / power supply / communication / IO, with built-in timing logic control and safety interlocks; it also has an option switch to disconnect the UPS power supply of other controllers to reduce load and ensure continuous operation.

[0009] Furthermore, the operating condition trigger signals include typical emergency events such as fire alarms, communication loss, and main power interruption; the on-site monitoring data includes control valve position, pressure, flow rate, and wellbore status process parameters.

[0010] Furthermore, the physical actuators include:

[0011] Valve actuators are used for critical operations such as pipeline replacement and well control. Diesel air compressor, high-voltage circuit breaker and central control load switching unit are used for emergency power switching and control of air supply guarantee; Seawater lift pumps, fire pumps, and diesel replacement / well control pumps are used for pipeline replacement and well control operations under different power and communication conditions.

[0012] Furthermore, the output layer is used to provide system operation results and status feedback, including: The status of pipeline replacement / well control completion is used to indicate that emergency operations have been successfully completed. Anomaly alarms are used to promptly trigger warnings when anomalies are detected during pipeline replacement or well control. The system shutdown status is used to restore the system to a safe shutdown mode after pipeline replacement or well control is completed.

[0013] Secondly, the technical solution adopted by this invention is as follows: a control method for subsea pipeline replacement and well control in emergency operating conditions of offshore unmanned platforms, based on the aforementioned control system for subsea pipeline replacement and well control in emergency operating conditions of offshore unmanned platforms, comprising: judging the power supply status of main power and emergency power and whether the sea-land communication is normal according to the distribution panel and communication status; calculating the temperature drop and blockage / safety critical time of the pipeline shutdown according to the material flow type and well condition, and starting a timer; when the critical time is reached, the system automatically enters the one-key replacement and well control process: if the main power and communication are normal, the seawater lift pump is turned on and the electric replacement pump is started; if the main power is lost but the communication is normal, the emergency motor is started and the seawater lift pump is turned on; if the emergency motor cannot be started but the communication is normal, the diesel fire pump is started to replace the seawater; if both the main power and communication are interrupted, the diesel replacement / well control pump is automatically started to complete the replacement and well control operation; after the subsea pipeline replacement and well control are completed, the pump, valve and compressor are shut down and the system enters a safe shutdown state.

[0014] Furthermore, the pipeline replacement sequence is as follows: preset valve position → pump start → pressure / flow confirmation → timed replacement → execution of intermediate / termination criteria → reset to a safe state; the wellbore kill sequence is as follows: isolate the corresponding wellhead according to the preset kill sequence → connect the kill pipeline → start the kill pump → control the wellhead / casing pressure → circulation replacement / backpressure → stabilize pressure and stop the pump → reset to a safe state.

[0015] Furthermore, the intermediate / termination criterion is as follows: the replacement water volume is calculated and measured by the displacement of the replacement pump and the pump outlet flow meter. When the volume of the subsea pipeline and well is reached, the replacement is considered complete.

[0016] Furthermore, the calculation of the temperature drop during pipeline shutdown for remote, fully autonomous replacement by an unmanned offshore oil and gas production platform is as follows: ; In the formula, Indicates to stop the operation Temperature of the medium inside the pipe after hours, in °C; This indicates the ambient temperature surrounding the pipeline, in °C. This indicates the temperature of the medium inside the pipe at the start of the shutdown, in °C. This indicates the outer diameter of the pipeline insulation layer, in meters (m). This represents the overall heat transfer coefficient of the pipeline, expressed in W / (m²). ℃); Indicates the downtime, in hours (h). This indicates the specific heat of the medium inside the pipe, expressed in J / (kg). ℃); This indicates the density of the medium inside the pipe, expressed in kg / m³. This indicates the inner diameter of the steel pipe, in meters (m). The specific heat of steel and insulation materials is expressed in J / (kg). ℃); This indicates the density of steel and insulation materials, expressed in kg / m³. This indicates the outer diameter of each layer of pipe, in meters (m). This indicates the inner diameter of each layer of pipe, in meters (m).

[0017] The present invention has the following advantages due to the adoption of the above technical solutions: 1. This invention can ensure the safety of submarine pipelines and wellbores in the event of unattended operation, low power conditions, and loss of communication between land and sea, and avoid oil and gas production interruption caused by crude oil solidification.

[0018] 2. This invention can ensure that pipeline replacement and well control operations are completed within the critical time window after production stoppage, thereby reducing production losses. Attached Figure Description

[0019] Figure 1 This is an operation flowchart of the autonomous replacement method for the entire process of an unmanned offshore oil and gas production platform in this embodiment of the invention; Figure 2 This is a schematic diagram of an emergency pipeline replacement scenario for an unmanned offshore platform, as described in this embodiment of the invention. Detailed Implementation To address the technical shortcomings of traditional solutions, this invention provides a dedicated control system and method for emergency pipeline replacement and well control on offshore unmanned platforms. This system enables autonomous replacement and well control operations under extreme conditions such as loss of main power, loss of emergency power, or disruption of sea-to-land communication. First, it collects power and communication status information through sensors, autonomously formulates emergency replacement and well control procedures, and then sequentially executes one-click replacement and well control operations based on the real-time status of actuators such as valves, pumps, and compressors. This invention effectively solves the problem of difficult manual intervention on unmanned platforms under emergency conditions, improves the safety and automation level of the replacement and well control processes, and provides key technical support for the application of unmanned platforms in high-pour-point oilfield development.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] In one embodiment of the present invention, a control system for emergency pipeline replacement and well control on an unmanned offshore platform is provided. This system is applicable to the unmanned, minimally staffed, and intelligent control of offshore oil and gas production platforms. Under extreme emergency conditions such as lack of emergency generator power or loss of communication between land and sea, the platform autonomously completes pipeline replacement and well control operations with minimal power requirements. In this embodiment, as shown... Figure 1 As shown, the system includes: The input layer includes operating condition trigger signals and on-site monitoring data; The control core layer includes: The status awareness module is used to collect signals from main power, emergency power, land and sea communication, and process monitoring. These signals include pressure, flow, valve status, and wellbore status. The module also collects, filters, and fuses the input layer's operating condition signals and monitoring data in real time to form a complete understanding of the operating conditions. The emergency decision-making module determines whether the platform should enter the replacement or well control process based on the monitoring signals from the status perception module, and makes decisions according to the preset emergency strategy, automatically selects the corresponding execution strategy, and enters the execution control module. The execution control module issues specific operation commands such as valve start / stop, pump start / stop, circuit breaker switching, and air compressor start / stop, and controls the valve actuator, diesel well kill pump, high voltage circuit breaker, seawater lift pump, fire pump, and diesel replacement pump equipment to sequentially realize replacement and well kill operations, and achieve automated control; The safety protection module provides functions such as fire interlock, overpressure alarm, and replacement failure protection while the execution control module is running, ensuring the operational safety of the unmanned platform under extreme conditions. The execution layer consists of the physical actuators of the control system, which control the actions of the physical actuators according to the control core layer. The output layer is used to provide the operating results and status feedback of the control system.

[0023] In the above embodiments, the control system for emergency pipeline replacement and well control of offshore unmanned platforms also includes an independent UPS power supply unit; the independent UPS power supply unit is physically isolated from the power supply of the platform's original PCS / ESD / FGS and other systems, meeting the autonomous replacement and well control operation requirements of [parameter: minimum continuous power supply time of UPS 1 hour]; and includes power supply diagnosis and low-voltage switching strategies.

[0024] In the above embodiments, the execution control module adopts a 1:1 redundant architecture of controller / power supply / communication / IO, with built-in timing logic control and safety interlocks; it has a selector switch to disconnect the UPS power supply of other controllers to reduce load and ensure continuous operation. It can also support NTP / IRIG clock synchronization.

[0025] In the above embodiments, the operating condition trigger signals include typical emergency events such as fire alarms, communication failures, and main power outages; the on-site monitoring data includes process parameters such as control valve positions, pressure, flow rates, and wellbore status. These input data are collected through sensors and control networks and transmitted to the control core layer for unified processing.

[0026] In the above embodiments, the physical actuator includes: Valve actuators are used for critical operations such as pipeline replacement and well control; among them, valve actuators include ball valves 6, 9, and 10-12 with remote control function.

[0027] Diesel air compressor, high-voltage circuit breaker and central control load switching unit are used for emergency power switching and control of air supply guarantee; Seawater lift pump 1, fire pump and diesel replacement / well kill pump 5 are used for pipeline replacement and well kill operations under different power and communication conditions.

[0028] The physical actuators also include seawater coarse filters 2 and 3, a displacement pump built-in filter 4, and production separators 7-8.

[0029] In this embodiment, the execution and detection interface layer includes: valve switching / regulation (DO / AI / DI), pump start / stop (DO), status / position signals (DI / AI); interfaces with fire pumps and diesel replacement / kill pumps 5, electric seawater lift pumps 1, kill pumps, launching tubes, receiving tubes 13, etc.; and bidirectional isolation and interlocking interfaces with FGS (fire and gas detection) and ESD (emergency shutdown) safety signals.

[0030] In the above embodiments, the output layer is used to provide system operation results and status feedback, including: The status of pipeline replacement / well control completion is used to indicate that emergency operations have been successfully completed. Anomaly alarms are used to promptly trigger warnings when anomalies are detected during pipeline replacement or well control. The system shutdown status is used to restore the system to a safe shutdown mode after pipeline replacement or well control is completed.

[0031] In the above embodiments, communication and autonomy switching are as follows: when sea and land communication is normal, remote control and monitoring are supported; when communication is lost, it automatically switches to the one-click autonomous process and executes the replacement and well control sequence according to the preset logic.

[0032] In the above embodiments, safety and minimum power consumption design includes: shutdown / fire suppression priority, fault bypass strategy, confirmation of critical valve positions / pump pressure, graded load reduction (shutting down high-pressure panels and shedding non-critical loads), and handling of abnormalities such as low temperature / low pressure / low liquid level.

[0033] Through the above structure, the dedicated control system in this embodiment of the invention can realize pipeline replacement and wellbore control operations under emergency conditions, including low power demand, loss of communication between land and sea, and unmanned operation. This system not only ensures the safe operation of unmanned offshore platforms in high-pour-point oilfield development but also significantly reduces the overall development investment of the oilfield.

[0034] In one embodiment of the present invention, a control method for emergency pipeline replacement and well control of an unmanned offshore platform is provided, which is implemented based on the control system for emergency pipeline replacement and well control of an unmanned offshore platform in the above embodiments. In this embodiment, as... Figure 2 As shown, the control method includes the following steps: 1) Based on the distribution panel and communication status, determine the power supply status of main power and emergency power, as well as whether sea and land communication is normal; 2) Based on the pipeline flow type and wellbore operating conditions, calculate the shutdown temperature drop and blockage / safety critical time, and start the timer; when the critical time is reached, the system automatically enters the pipeline replacement and well control process: If the main power and communication are normal, turn on the seawater lift pump and start the electric displacement pump. If the main power is lost but communication is normal, start the emergency unit and turn on the seawater lift pump; If the emergency unit fails to start but communication is normal, start the diesel fire pump to displace the seawater. If both main power and communication are interrupted, the diesel replacement pump will be automatically started to complete the pipeline replacement and well control operations. 3) After the pipeline replacement and well kill are completed, shut down the pumps, valves and compressors and enter a safe shutdown state.

[0035] In the above embodiments, the subsea pipeline replacement sequence is as follows: preset valve position → pump start → pressure / flow confirmation → timed replacement → execution of intermediate / termination criteria → reset to a safe state. The wellbore kill sequence is as follows: isolate the corresponding wellhead according to the preset kill sequence → connect the kill pipeline → start the kill pump → control the wellhead / casing pressure → circulate replacement / backpressure → stabilize pressure and stop the pump → reset to a safe state.

[0036] Specifically, such as Figure 2As shown, the seawater booster pump 1 is started according to the preset valve position. The oil and gas pass through two seawater coarse filters 2 and 3 respectively and then enter the built-in filter 4 of the displacement pump for further filtration. The filtered oil and gas are pumped into the ball receiving cylinder 13 by the displacement pump 5. After passing through the ball receiving cylinder 13, the oil and gas enter the production separators 7 and 8 in sequence to separate the oil and gas. The separated oil enters the oil tank. A ball valve 9 with remote control function is installed at the outlet of the displacement pump 5, ball valves 6 with remote control function are installed at both ends of the ball receiving cylinder 13, ball valve 10 with remote control function is installed between the ball receiving cylinder 13 and the production separator 7, ball valve 11 with remote control function is installed between the two production separators 7 and 8, and ball valve 12 with remote control function is installed at the outlet of the production separator 8.

[0037] In this embodiment, the intermediate / termination criterion is: the displacement water volume is calculated and measured by the displacement pump displacement and the pump outlet flow meter. When the displacement water volume reaches the volume of the subsea pipeline and well (a safety factor of 1.1 can be taken), the displacement is considered complete.

[0038] In step 1) above, the working condition judgment specifically involves: collecting the status of the main power supply, emergency unit, communication, and FGS / ESD, and then entering the emergency mode.

[0039] In step 2) above, the temperature drop calculation for the remote, fully autonomous pipeline shutdown replacement by the offshore unmanned oil and gas production platform is as follows: ; In the formula, Indicates to stop the operation Temperature of the medium inside the pipe after hours (°C); Indicates the ambient temperature (°C) outside the pipeline; This indicates the temperature of the medium inside the pipe (°C) at the start of the shutdown process. Indicates the outer diameter of the pipeline insulation layer (m); The overall heat transfer coefficient of the pipeline (W / (m2)) ℃)); Indicates the downtime (h); The specific heat of the medium inside the pipe (J / (kg)) ℃)); Indicates the density of the medium inside the pipe (kg / m3); Indicates the inner diameter of the steel pipe (m); The specific heat of steel and insulation materials (J / (kg)) ℃)); This indicates the density of steel and insulation materials (kg / m3). Indicates the outer diameter (m) of each layer of pipe; This indicates the inner diameter (m) of each layer of pipe.

[0040] In step 2) above, the decision to enter the pipeline replacement and well control process is made using a pipeline replacement / well control trigger criterion. The pipeline replacement / well control trigger criterion is as follows: calculate the temperature drop during shutdown and the critical time T_crit for blockage / safety. The process is triggered when the timer reaches the threshold or the interlocking condition is met.

[0041] Step 2 above also includes load reduction and preparation: performing necessary ESD sectional shutdown, disconnecting non-critical loads, and confirming that the replacement / kill pipeline valve positions meet the prerequisites.

[0042] Pump source selection: prioritize electric seawater lift pump; if there is no main power, use emergency pump; if emergency pump is unavailable, switch to diesel fire pump / diesel replacement pump.

[0043] In step 2) above, the wellbore kill sequence is as follows: Isolate the corresponding wellhead according to the preset kill sequence—connect the kill pipeline—start the kill pump—control the wellhead / casing pressure—circulate replacement / backpressure—stabilize the pressure and stop the pump—reset to a safe state.

[0044] In step 3) above, the process ends and resets: the pump is stopped, the valve is closed, the data is recorded and self-tested, and the system is restored to a safe standby state.

[0045] It should be noted that each step includes branches such as "not satisfied → alarm → retry / bypass / shutdown" and safety interlock priorities such as fire / venting.

[0046] The system provided in this embodiment is used to execute the above-described method embodiments. For specific processes and details, please refer to the above embodiments, which will not be repeated here.

[0047] One embodiment of the present invention provides a computing device, which can be a terminal and may include: a processor, a communication interface, memory, a display screen, and an input device. The processor, communication interface, and memory communicate with each other via a communication bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs, which are executed by the processor to implement the methods described in the above embodiments. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wi-Fi, a network management system, NFC (Near Field Communication), or other technologies. The display screen can be a liquid crystal display or an e-ink display. The input device can be a touch layer covering the display screen, or buttons, a trackball, or a touchpad mounted on the casing of the computing device, or an external keyboard, touchpad, or mouse. The processor can call logical instructions stored in the memory.

[0048] In one embodiment of the present invention, a computer program product is provided, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, and when the program instructions are executed by a computer, the computer is able to perform the methods provided in the above-described method embodiments.

[0049] In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, which stores server instructions that cause a computer to perform the methods provided in the above embodiments.

[0050] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control system for emergency pipeline replacement and well control on unmanned offshore platforms, characterized in that, include: The input layer includes operating condition trigger signals and on-site monitoring data; The control core layer includes: The status sensing module is used to collect main power, emergency power, sea and land communication and process monitoring signals, including pressure, flow, valve status and wellbore status. The emergency decision-making module determines whether the platform should enter the replacement or well control process based on monitoring signals, and automatically selects the corresponding execution strategy and enters the execution control module; The execution control module controls the valve actuator, diesel well-kill pump, high-voltage circuit breaker, seawater lift pump, fire pump, and diesel replacement pump equipment to sequentially realize replacement and well-kill operations; The safety protection module provides fire interlock, overpressure alarm, and replacement failure protection functions while the execution control module is running, ensuring the operational safety of the unmanned platform under extreme conditions. The execution layer consists of the physical actuators of the control system, which control the actions of the physical actuators according to the control core layer. The output layer is used to provide the operating results and status feedback of the control system.

2. The control system for emergency pipeline replacement and well control of offshore unmanned platforms as described in claim 1, characterized in that, Includes an independent UPS power supply unit; the independent UPS power supply unit is physically isolated from the original PCS / ESD / FGS system power supply of the platform, and has power diagnosis and low voltage switching strategy.

3. The control system for emergency pipeline replacement and well control of offshore unmanned platforms as described in claim 1, characterized in that, The execution control module adopts a 1:1 redundant architecture of controller / power supply / communication / IO, with built-in timing logic control and safety interlocks; it has a selector switch to disconnect the UPS power supply of other controllers to reduce load and ensure continuous operation.

4. The control system for emergency pipeline replacement and well control of offshore unmanned platforms as described in claim 1, characterized in that, Operating condition trigger signals include typical emergency events such as fire alarm, communication failure, and main power interruption; on-site monitoring data include control valve position, pressure, flow rate, and wellbore status process parameters.

5. The control system for emergency pipeline replacement and well control of an unmanned offshore platform as described in claim 1, characterized in that, Physical actuators include: Valve actuators are used for critical operations such as pipeline replacement and well control. Diesel air compressor, high-voltage circuit breaker and central control load switching unit are used for emergency power switching and control of air supply guarantee; Seawater lift pumps, fire pumps, and diesel replacement / well control pumps are used for pipeline replacement and well control operations under different power and communication conditions.

6. The control system for emergency pipeline replacement and well control of an unmanned offshore platform as described in claim 1, characterized in that, The output layer is used to provide system operation results and status feedback, including: The status of pipeline replacement / well control completion is used to indicate that emergency operations have been successfully completed. Anomaly alarms are used to promptly trigger warnings when anomalies are detected during pipeline replacement or well control. The system shutdown status is used to restore the system to a safe shutdown mode after pipeline replacement or well control is completed.

7. A control method for emergency pipeline replacement and well control of an unmanned offshore platform, implemented based on the control system for emergency pipeline replacement and well control of an unmanned offshore platform as described in any one of claims 1 to 6, characterized in that, include: Based on the status of the distribution panel and communication, determine the power supply status of the main power and emergency power, as well as whether the sea and land communication is normal; Based on the pipeline flow type and wellbore operating conditions, calculate the temperature drop during shutdown and the critical time for blockage / safety, and start a timer; when the critical time is reached, the system automatically enters the one-click replacement and well control process: If the main power and communication are normal, turn on the seawater lift pump and start the electric displacement pump. If the main power is lost but communication is normal, start the emergency unit and turn on the seawater lift pump; If the emergency unit fails to start but communication is normal, start the diesel fire pump to displace the seawater. If both main power and communication are interrupted, the diesel replacement / kill pump will be automatically started to complete the replacement and kill operations; After the pipeline replacement and well control are completed, the pumps, valves and compressors are shut down and the system enters a safe shutdown state.

8. The control method for emergency pipeline replacement and well control of offshore unmanned platforms as described in claim 7, characterized in that, The pipeline replacement sequence is as follows: Preset valve position → Pump start → Pressure / flow confirmation → Timed replacement → Execution of intermediate / termination criteria → Reset to a safe state; Wellbore kill sequence is as follows: Isolate the corresponding wellhead according to the preset kill sequence → Connect the kill pipeline → Start the kill pump → Control the wellhead / casing pressure → Circulate replacement / backpressure → Stabilize pressure and stop the pump → Reset to a safe state.

9. The control method for emergency pipeline replacement and well control of an unmanned offshore platform as described in claim 8, characterized in that, The intermediate / termination criterion is as follows: the replacement water volume is calculated and measured by the displacement of the replacement pump and the pump outlet flow meter. When the volume of the subsea pipeline and well is reached, the replacement is considered complete.

10. The control method for emergency pipeline replacement and well control of an unmanned offshore platform as described in claim 8, characterized in that, The calculation of temperature drop during remote, fully autonomous pipeline shutdown replacement by an unmanned offshore oil and gas production platform is as follows: ； In the formula, Indicates to stop the operation Temperature of the medium inside the pipe after hours, in °C; This indicates the ambient temperature surrounding the pipeline, in °C. This indicates the temperature of the medium inside the pipe at the start of the shutdown, in °C. This indicates the outer diameter of the pipeline insulation layer, in meters (m). This represents the overall heat transfer coefficient of the pipeline, expressed in W / (m²). ℃); Indicates the downtime, in hours (h). This indicates the specific heat of the medium inside the pipe, expressed in J / (kg). ℃); This indicates the density of the medium inside the pipe, expressed in kg / m³. This indicates the inner diameter of the steel pipe, in meters (m). The specific heat of steel and insulation materials is expressed in J / (kg). ℃); This indicates the density of steel and insulation materials, expressed in kg / m³. This indicates the outer diameter of each layer of pipe, in meters (m). This indicates the inner diameter of each layer of pipe, in meters (m).

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