Safety Assessment Of Submarine Pipelines And System Development

Submarine pipelines have been widely used as one of the most economical ways of transmitting oil and gas from the offshore oil fields to the terminals. As important part of lifeline engineering, it's necessary to analyze safety assessment of submarine pipelines. Marine Environment, oil and gas affects submarine pipelines in four ways. And these effects often impose on submarine pipelines at the same time. Flexural capacity of pipe with corrosion defects and on-bottom pipeline stability are analyzed firstly. Then base on the study above, safety assessment of submarine pipelines is undertaken, health monitoring and safety assessment system of submarine pipelines is designed and developed.Based on the interaction criterion of multi-axial stress proposed by Galambos, flexural capacity of corroded pipes with both internal and external corrosive defects can be determined analytically assuming a full plastic failure mode for the pipe subject to combined external pressure, internal pressure, axial force and bending moment. Comparison of predicted results and experimental results tested by Miyazaki is performed to validate the method proposed in the paper. Deterministic and reliability assessment of flexural capacity of corroded pipes is undertaken in the end.The force model of pipes is analyzed. Base on the Morison equation, hydrodynamic is presented. Then in view of hydrodynamic, soil resistance, weight and buoyancy, deterministic and reliability assessment of on - bottom pipeline stability is undertaken in the end.Health monitoring and safety assessment system of submarine pipelines is designed base on VB, JSP, VRML, SQL. It contains monitoring model subsystem, data docking subsystem, data querying subsystem, parameters setting subsystem, safety assessment subsystem, user management subsystem and help querying subsystem.According to marine test conditions and pipeline with corrosion defects simulated, health monitoring and safety assessment system of submarine pipelines is designed and developed. Then the system is debugged and it runs well. The basic functions of health monitoring and safety assessment of submarine pipelines are achieved preliminarily.