Study On Impact Assessment Of Anchor Damage And Early Warning Of Submarine Pipeline

Anchor impact is dominant failure mode of submarine pipeline third-party damage.It has great significance to develop the inspection and early warning technique to reflect the state of submarine pipeline damage exactly for the prevention of production and oil spill accidents,and reasonable using of submarine pipeline resources.The monitoring system installed on the submarine pipeline so far,are mostly aimed at the monitoring body and corrosion of submarine pipeline.The monitoring and safety early warning for the damage of submarine pipeline is still in its infancy and exploration stage.Based on the laws and regulations,industry technical standards,according to the theory of safety evaluation and concave deep damage evaluation theory,combined with test method,the theory correction model of submarine pipeline sag depth and load is established.Using on-line monitoring technology,damage evaluation technology and real-time communication technology,based on real-time data analysis,a submarine pipeline damage early-warning system is constructed to implement risk assessment,monitoring of injury,damage analysis,control and real-time warning for submarine pipeline so as to provide reliable theoretical and technical supporting for reducing the risk of submarine pipeline anchor damage,and scientific real-time warning.This research work focuses on Six aspects:Firstly,research on safety barrier theory and hazard of submarine pipeline: with collected accident data of submarine pipeline,Bowtie theory bow-tie models of oil and gas leakage of anchor impact for submarine pipeline are set up to interpret the accident developing process from the cause to the control,and the consequence.Based on the theory of the safety barrier,a model of oil and gas leakage of submarine pipeline is established,in which monitoring and early warning are built up as the safety barrier for oil and gas leakage and the necessity of establishing warning system for submarine pipeline is demonstrated.Secondly,test method for anchor damage detection of submarine pipeline: A system of submarine pipeline anchor damage tests is constructed to simulate anchor strike damage evolution process under ocean environment.According to the requirement of the automatic on-line monitoring,a set of anchor damage detection system for submarine pipeline is developed,which can real-time monitor the change of characteristic parameters of the anchor strike damage,which will lay a foundation for anchor damage on-line monitoring test of submarine pipeline.Thirdly,study on the characteristics of regional strain change in the cavity area of submarine pipeline.The system of submarine pipeline damage test is applied to demonstrate the anchor strike damage of submarine pipeline.On the sample in full size of submarine pipeline,anchor strike damage experiment is conducted.Under the typical load conditions,mechanics response characteristic of submarine pipeline anchor strike damage is analyzed.Strain variation characteristic is analyzed with the software of Abqus,and damage deformation law is obtained.Sensitive parameters are proposed and damage criterion is established,which lays a foundation for the damage evaluation method of submarine pipeline in cavity area.Forthly,the theoretical model on deepness of concave and damage evaluation of submarine pipeline concavity area: According to the characteristics of submarine pipeline anchor damage,the characteristics of depth of concavity under different influence factors are analyzed.With the pipe size and working conditions taken into consideration,anchor damage tests are designed under the condition of sand and sea.Based on the test data,the load and the sag depth theory formula is corrected and the Damage assessment model of submarine pipeline is obtained based on the corrected formula.Providing a reliable theory basis for the damage assessment of submarine pipeline.With DNV damage assessment standard,the anchor strike damage of submaring pipeline is evaluated under different conditions.It provides reliable data support for the construction of the submarine pipeline damage warning system.Fifthly,construction of an early warning system for submarine pipeline damage: A damage early-warning system of submarine pipeline is developed,which includes the maritime communications buoys,data servers and client software based on GIS technology,and communications integration technology.This system could be used in submarine pipeline risk assessment,damage identification and real-time warning.Sixthly,early warning software platform of submarine pipeline damage and early warning implementation.An early warning system software for buoy tracking based on Google electronic map matching is developed.The software is used with buoy to realise friendly interaction among data of buoy,server and the client.And data is real-time displayed in the client's electronic map so that the real-time track of damage monitoring and early warning of submarine pipeline can be realised.In order to verify the effectiveness of the early warning system and related software,anchor strike damage and early warning and comprehensive test experiment are designed under the condition of sea.The experiments show that the submarine pipeline damage warning system can play the functions of positioning,and damage,and real-time warning,it runs normally,and the result is reliable.