Natech (Natural Hazard Triggering Technological Disasters) Events Risk Management: An Operational Approach

Abstract The intersection of intense natural events with industrial operations can lead to catastrophic consequences such as the so-called Natech, which are, by definition, natural hazards triggering technological disasters. The present contribution outlines an operational approach for the assessment of Natech risks in onshore Oil &Gas facilities. The novel procedure consists of two phases. In Phase 1, a preliminary screening is carried out to identify the natural hazards of concern and the vulnerable equipment items within the premises of the facility. This screening is based on awareness questionnaires and reference hazard databases to qualitatively and quantitatively assess the level of hazard related to different natural events. A preliminary ranking of the vulnerability level of the plant units based on the potential damage and severity of consequences from the natural event scenarios of concern is then carried out. This allows the identification of the equipment items that are more vulnerable to natural events. In Phase 2, a detailed quantification of Natech risk is carried out, limited to the vulnerable units identified in the preliminary screening. The assessment involves the calculation of the damage probabilities for equipment items, the identification of credible scenarios based on substance involvement and storage conditions, and the characterization of the credible scenarios in terms of expected frequencies and consequences. Lastly, the overall Natech risk at the site is quantified through specific risk indexes. The method was applied to an Oil & Gas upstream installation, demonstrating the effectiveness of the innovative approach proposed in identifying and quantifying vulnerability and risk generated by Natech scenarios. Measures for mitigating the consequences of potential Natech accidents were also identified.