CN-122014159-A - Control system and control method for sea pipe replacement and well killing under emergency working condition of offshore unmanned platform

CN122014159ACN 122014159 ACN122014159 ACN 122014159ACN-122014159-A

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 pipe replacement and well killing under the emergency working condition of the offshore unmanned platform, wherein the control system comprises an input layer, a control core layer and a control system, wherein the control core layer comprises a state sensing module, a control module and a control module, wherein the state sensing module is used for acquiring main electricity, emergency electricity, sea-land communication and process monitoring signals; the emergency decision module judges whether the platform enters a replacement or well-killing process according to the monitoring signal and automatically selects a corresponding execution strategy to enter an execution control module, the execution control module controls a valve executing mechanism, a diesel oil well pump, a high-voltage circuit breaker, a seawater lifting pump, a fire pump and a diesel oil replacement pump device to sequentially realize replacement and well-killing operation, the safety protection module provides fire interlocking, overpressure alarming and replacement failure protection functions when the execution control module operates, the execution layer controls the physical executing mechanism to act according to a control core layer, and the output layer is used for providing operation results and state feedback of a control system.

Inventors

CHEN DI
LIU BOYING
HE XIAOYONG
ZHANG YI
ZHU CHUNLI
ZHANG YING
ZHONG YUTONG
WANG TINGTING
Jia chuang
LI XIANLIN

Assignees

中海石油(中国)有限公司
中海石油（中国）有限公司北京研究中心

Dates

Publication Date: 20260512
Application Date: 20260324

Claims (10)

1. A control system for marine pipe replacement and kill for an offshore unmanned platform under emergency conditions, comprising: The input layer comprises a working condition trigger signal and field monitoring data; A control core layer comprising: The state sensing module is used for collecting main electricity, emergency electricity, sea-land communication and process monitoring signals, wherein the monitoring signals comprise pressure, flow, valve state and shaft state; The emergency decision module judges whether the platform enters a replacement or well control process according to the monitoring signal, automatically selects a corresponding execution strategy and enters an execution control module; the execution control module is used for controlling a valve execution mechanism, a diesel oil pressure well pump, a high-voltage circuit breaker, a seawater lifting pump, a fire pump and a diesel oil displacement pump device to realize displacement and well control operation in sequence; The safety protection module provides fire interlocking, overpressure alarming and replacement failure protection functions when the control module is executed to run, so that the operation safety of the unmanned platform under the extreme working condition is ensured; the execution layer is a physical execution mechanism of the control system and controls the physical execution mechanism to act according to the control core layer; and the output layer is used for providing a control system operation result and state feedback.
2. The control system for offshore unmanned platform emergency condition sea pipe displacement and well killing of claim 1, comprising an independent UPS power supply unit, wherein the independent UPS power supply unit is physically isolated from a platform primary PCS/ESD/FGS system power supply, and the power diagnosis and low-voltage switching strategy are implemented.
3. The control system for marine pipe replacement and well killing under the emergency working condition of the unmanned offshore platform according to claim 1, wherein the execution control module adopts a controller/power supply/communication/I-O1:1 redundant architecture, is internally provided with a time sequence logic control and safety interlocking, and is provided with a selection switch for disconnecting the UPS power supply of other controllers so as to reduce load and keep-alive.
4. The control system for marine pipe displacement and killing for an unmanned offshore platform emergency condition of claim 1, wherein the condition triggering signal comprises a fire alarm, a communication loss, a main electricity interruption typical emergency event, and the field monitoring data comprises a regulating valve position, a pressure, a flow rate, and a well bore state process parameter.
5. The control system for marine pipe displacement and killing for an unmanned marine platform emergency condition of claim 1, wherein the physical actuator comprises: the valve actuating mechanism is used for the key operation of sea pipe replacement and shaft well control; The diesel air compressor, the high-voltage circuit breaker and the central control load switching unit are used for switching emergency power supplies and controlling air supply guarantee; The seawater lifting pump, the fire pump and the diesel oil displacement/well killing pump are used for sea pipe displacement and well killing operation under different electric power and communication conditions.
6. The control system for marine pipe displacement and killing for an offshore unmanned platform emergency condition of claim 1, wherein the output layer is configured to provide system operation results and status feedback, comprising: The sea pipe replacement/well killing completion state is used for indicating that the emergency operation is successfully completed; the abnormal alarm is used for triggering an alarm in time when abnormality is found in the process of sea pipe replacement or well killing; And the system is in a shutdown state and is used for restoring the system to a safe shutdown mode after the sea pipe replacement or well killing is finished.
7. A control method for offshore unmanned platform emergency condition sea pipe displacement and well killing, implemented based on the control system for offshore unmanned platform emergency condition sea pipe displacement and well killing according to any one of claims 1 to 6, comprising: judging whether the power supply condition of main electricity and emergency electricity and sea-land communication are normal or not according to the distribution board and the communication state; According to the type of the logistics in the sea pipe and the working condition of the shaft, calculating the critical time of temperature drop and blockage/safety, starting a timer, and when the critical time is reached, automatically entering a one-key replacement and well control process: if the main electricity and communication are normal, starting the seawater lifting pump and starting the electric displacement pump; if the main power is lost and the communication is normal, starting an emergency machine and starting a seawater lifting pump; If the emergency machine cannot be started but the communication is normal, starting a diesel fire pump to replace seawater; If the main power and the communication are interrupted, automatically starting a diesel oil replacement/well-killing pump to complete replacement and well-killing operation; after the sea pipe replacement and well killing are completed, the pump, the valve and the compressor are closed, and the safe shutdown state is achieved.
8. The method for controlling sea pipe displacement and well killing under the emergency working condition of the unmanned offshore platform according to claim 7, wherein the sea pipe displacement sequence comprises the steps of according to a preset valve position, pumping start, pressure/flow confirmation, timing displacement, middle/termination criterion execution, resetting to a safe state, and the well killing sequence comprises the steps of according to a preset well killing sequence, isolating a corresponding well head, connecting a well killing pipeline, starting a well killing pump, controlling the well head/casing pressure, circulating displacement/back pressure, stabilizing the pressure, stopping the pump and resetting to the safe state.
9. The method of claim 8, wherein the intermediate/termination criteria is calculating and measuring the displaced water volume by displacing pump displacement and pump out flow meters, and determining that the displacement is complete after the sea pipe and wellbore volume are reached.
10. The control method for marine pipe displacement and killing for the emergency working condition of the unmanned offshore platform according to claim 8, wherein the remote overall process autonomous displacement pipeline stopping and temperature drop of the unmanned offshore oil and gas production platform is calculated as: ; In the formula, Indicating a stop of transportation After the hour, the medium temperature in the tube is set as the unit of the temperature; Represents the ambient temperature of the pipeline periphery, and is expressed as a unit of DEG C; the medium temperature in the pipe at the beginning of stopping the transportation is expressed in the unit of DEG C; The outer diameter of the pipeline heat-insulating layer is represented by m; represents the total heat transfer coefficient of the pipeline, and the unit is W/(m 2) °C); The stop time is represented by h; the specific heat of the medium in the tube is expressed as J/(kg) °C); The density of the medium in the tube is expressed in kg/m3; the inner diameter of the steel pipe is represented by m; the specific heat of the steel and the heat insulation material is expressed as J/(kg) °C); The density of the steel and the heat insulation material is expressed in kg/m3; the outer diameter of each layer of pipe is represented by m; The inner diameter of each layer tube is expressed in m.

Description

Control system and control method for sea pipe replacement and well killing under emergency working condition of offshore unmanned platform Technical Field The invention relates to the technical field of unmanned and intelligent control of an offshore unmanned oil and gas production platform, in particular to a control system and a control method for sea pipe replacement and well killing under emergency working conditions of the offshore unmanned platform. Background When the offshore high-condensation oil field is scheduled to stop production or is stopped in accident, if the line sweeping/replacement of the offshore pipe and the well killing of the shaft cannot be completed in time, the risks of crude oil solidification, wax deposition or hydrate easily occur, so that the pipeline is blocked, the shaft is unstable, and the production stopping time of the oil field is obviously prolonged. The traditional scheme relies on the cooperation of field personnel, a central control system and emergency machine power and sea-land communication, and has the defects that (1) an unmanned platform and open sea facilities are in field absence and wait climb a hill window time is long, (2) emergency replacement and well control duration often exceeds the conventional UPS (uninterrupted power supply) continuous voyage, (3) when sea-land communication is not connected, remote manual replacement/well control cannot be carried out, and (4) after a plurality of platforms/sea Liu Xietong are closed, a key valve and a pump still need to be controlled logically in sequence for a long time. Thus, there is a need for a dedicated control system that can operate autonomously with minimal power supply, even under communication disruption conditions. Disclosure of Invention Aiming at the problems, the invention aims to provide a control system and a control method for sea pipe replacement and well killing under the emergency working conditions of an offshore unmanned platform, wherein the autonomous execution of sea pipe one-key replacement and well killing operation of a shaft is realized through independent power supply and sequential logic under the emergency working conditions of no main power, no emergency power, sea-land disconnection and the like, and the safety of fire and gas, the completeness of interlocking and the minimum power load are ensured. The control system for the marine pipe replacement and well killing under the emergency working condition of the unmanned platform comprises an input layer, a control core layer, a state sensing module, an emergency decision making module, an output layer and a control system, wherein the input layer comprises a working condition triggering signal and on-site monitoring data, the control core layer comprises a state sensing module and is used for collecting main electricity, emergency electricity, sea-land communication and process monitoring signals, the monitoring signals comprise pressure, flow, valve states and shaft states, the emergency decision making module judges whether the platform enters the replacement or well killing process according to the monitoring signals and automatically selects corresponding execution strategies to enter an execution control module, the execution control module is used for controlling a valve executing mechanism, a diesel oil well pump, a high-voltage circuit breaker, a sea water lifting pump, a fire pump and a diesel oil replacement pump device to sequentially realize replacement and well killing operation, the safety protection module is used for providing fire interlocking, overpressure alarming and replacement failure protection functions when the execution control module is operated, the execution layer is used for controlling physical executing the physical executing mechanism of the control system according to the control core layer to control physical executing mechanism action, and the output layer is used for providing operation and state feedback of the control system. The system further comprises an independent UPS power supply unit, wherein the independent UPS power supply unit is physically isolated from a system power supply such as a platform primary PCS/ESD/FGS, and the like, and is provided with a power diagnosis and low-voltage switching strategy. Furthermore, the execution control module adopts a controller/power supply/communication/I-O1:1 redundancy architecture, is internally provided with a time sequence logic control and safety interlocking, and is provided with a selection switch for disconnecting the UPS power supply of other controllers so as to reduce load and keep running. Further, the working condition triggering signals comprise fire alarm, communication disconnection and typical emergency event of main power interruption, and the on-site monitoring data comprise valve position, pressure, flow and shaft state technological parameters of the regulating valve. Further, the physical actuator includes: the valve act