Risk assessment of submarine pipelines using modified FMEA approach based on cloud model and extended VIKOR method

The development of offshore oil and gas resources is inevitable for a submarine pipe network. Submarine pipeline leakage can easily escalate into a catastrophic event, causing enormous loss of life and property and environmental pollution. Therefore, it is imperative to conduct risk assessments of submarine pipelines. A failure mode and effects analysis (FMEA) is a significant method in risk analysis. However, due to the uncertainty in the risk analysis process, the assessment results may not be sufficiently accurate. In this paper, to evaluate the risk of submarine pipeline with enhanced reliability, an improved FMEA method based on cloud model and extended vlsekriterijumska optimizacija i kompromisno resenje (VIKOR) is proposed. The main contributions of this method are as follows. First, to minimize the associated linguistic uncertainties during the evaluation process, the cloud model theory is used, enabling the fuzziness and randomness to be comprehensively considered. Second, an improved synthetic dynamic weight algorithm, considering the personal status of experts as well as the agreement degree and confidence level of expert comments is proposed to strengthen the knowledge of the experts to minimize incompleteness. Third, an extended twolevel risk factor hierarchy of submarine pipeline failure is established to improve the comprehensiveness of risk assessment, meanwhile, an integrated weighting method considering both subjective and objective aspects is utilized to obtain the risk factor weights, which can comprehensively reveal the risk factors' relative importance. Fourth, the VIKOR method is extended with the cloud model to determine the risk priority of failure modes, which can offer a compromise solution in the context of uncertainty. Furthermore, a case study on a submarine pipeline of the Chengbei oilfield in China is performed to illustrate the applicability of proposed approach. Sensitivity analysis are carried out to observe the robustness of the proposed method. Finally, the comparison between the obtained results and that from pre-existing methods shows that the proposed method is a more accurate and effective method for the risk assessment of a submarine pipeline. (c) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.