Operational Risk Analysis of LNG Loading

Abstract

This article, written by Assistant Technology Editor Karen Bybee, contains highlights of paper OTC 20982, ’Operational Risk Analysis of LNG Loading,’ by B.H.K. Chin, P. Friis-Hansen, and T.G. Saetren, Det Norske Veritas, originally prepared for the 2010 Offshore Technology Conference, Houston, 3-6 May. The paper has not been peer reviewed. The increased interest in risk analysis is the result of several operators wanting to understand properly their risks in the operational phase, and in this way, through proper preparedness, to avoid or mitigate incidents and major accidents and to improve resilience toward these unwanted events. The full-length paper presents the results of a detailed risk analysis of a liquefied natural-gas (LNG) export loading operation at a jetty. The analysis takes into account the interaction between the vessel crew and the land-based operators. Introduction The objective of operational risk management is to satisfy multiple requirements of multiple stakeholders to control losses from operations. One particular objective of an operational-risk-management system is that it should provide a strong ability to forecast conditions and give input to management before the development of dangerous conditions. A second objective is to approach risk in a holistic way in assessing risk from unwanted losses resulting from loss of life and property and the effects on the environment. This requires a thorough understanding of the technical-systems reliability, of the organizational performance, and of how the interaction between the two affects the total-systems performance. This implies that a practical requirement for risk management of unwanted losses during the operation phase is that the risk modeling should encompass the systemic interactions between technical and human organizations. The solution for systemic risk requires a holistic perspective in hazard identification, risk analysis, and risk mitigation. This may provide the operator with a useful set of risk-based indicators to guide the risk-management process. Case-Study Description The intent of the test case is to model the loading mode at an LNG jetty, identifying potential failure scenarios and determining the risk profile for the loading operation. The main objective is to determine the safety and on-time performance of the loading operation. The investigation examines the possibility of technical failures, the errors caused by individual human performance, the organizational influences on the operation, and the combined factors from interfacing two sets of technical and human organizational systems (i.e., the land-based jetty operation and the ship-based operation). The process of transporting LNG has inherent risks associated with it. The LNG is handled in cryogenic conditions and if released, the vaporized gas can form a flammable or explosive mix with air at a flammable range of 5 to 15% concentration. The LNG carrier is on fixed charter, and the delivery performance is affected directly by the on-time performance of the LNG loading.