Risk-Based Inspection For Offshore Pipeline

Risk-Based Inspection(RBI)is a computing tool,mostly used in the oil and gas fields,which supports in the recognition of high priority substances(i.e.,those with high level of risk)vs.low priority substances(i.e.,those with low level of risk).This method allows the operators of the resources to make best use of the efficiency of their inspection assets/resources by focussing on those resources that pose the peak risk and not misuse of the resources that are basically insignificant.It would also be highly beneficial to perform a RBI study already during the design of a new pipeline.When properly implemented,risk-based inspection is highly effective in improving pipeline safety,compared to conventional code-based inspection programs.The objectives of RBI are to maximize safety,to minimize costs and to gain a technical understanding of the behavior and performance of the facilities.In this research two types of pipeline(steel pipeline and flexible pipeline)were instigated by using RBI methodology.The investigation of steel pipeline is carried out,in which,in-line corrosion growth rate detected in a carbon steel pipe.The internal corrosion caused by the presence of CO2 has been detected by using Magnetic Flux Leakage(MFL)inspection method and analyzed by using NORSOK's standard M-506 corrosion prediction model.A case study on simulation and prediction of CO2 corrosion growth rate is presented by using Risk-Based Inspection(RBI)methodology.The analysis of the effects of various parameters on corrosion growth was carried out for ensuring the integrity of the proposed methodology.For analyzing flexible pipeline,the latest version of industrial report on Pipeline and Riser Loss of Containment(PARLOC 2012)published by UK Oil&Gas authority has been used to investigate the failure rate and major degradation mechanisms arising throughout the flexible pipeline system.The risk levels of the sensitive locations are estimated based on the Quantitative Risk-Based Inspection(RBI)methodology.In order to prepare adequate inspection planning for flexible pipeline system,the high-risk locations have been visualized for ensuring the integrity of the proposed methodology.