Societal risk assessment of terminal and oil refinery unit

Abstract

This paper presents the societal risk assessment of oil refinery in one of the oil companies in East Java. The oil company operates-a terminal for loading and unloading of variety petrochemical products. The products are categorized as flammable which could be hazardous. To prevent unlikely event of hazards such as fire, risk assessment is needed to know the level of risk and propose any mitigation if the risk is unacceptable. The risk assessment is done for all the processes that occurs such as loading and unloading of products and the chemical process in the oil refinery. The system is categorized into 8 nodes based on their function. Firstly, Hazard and Operability (HAZOP) is carried out using BS IEC 61882 standard to identify the deviation of the system, the causes and how to prevent it. The frequency analysis of failure of component is done by using Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) which based on the DNV failure guidance and Oil and Gas Producers (OGP) data as input. In order to know the level of consequence, fire modelling is carried out to simulate how the jet fire and pool fire could impact into the social around the oil refinery in form of heat intensity. The fire modelling for the pool fire and jet fire results the pool radius and flame length respectively, based on the heat intensity of 4 kW/m2, 12.5 kW / m2, and 37.5 kW / m2. Risk is represented using F-N curve with UK-HSE standard. There is unacceptable risk that incurred for jet fire in pipeline and its components from the feedstock tank into pre-cut column, scenario 200 mm hole diameter. Mitigation is done using LOPA to bring the risk to the acceptable region by adding a gas detector which has changed the frequency of system failure from 1.44E-03 to 2.88E-06.