Modeling and analysis of flammable gas dispersion and deflagration from offshore platform blowout

Blowout is a catastrophic accident in offshore drilling operations, and it poses a serious threat to the operational safety of an offshore platform. This paper uses a computational fluid dynamics (CFD) model to simulate an offshore platform blowout accident and to assess its impact on the assets and personnel. It integrates the dispersion of flammable gas with the subsequent deflagration due to the accidental ignition. The dispersion behavior of blowout gas with wind is predicted and the hazardous area generated on an offshore platform is assessed. Also, the effect of well productivity on the blowout gas dispersion is examined. Subsequently, the deflagration scenario due to ignition of flammable gas is simulated to predict the deflagration loads including overpressure, high temperature and heat radiation. Eventually, the impact of blowout gas deflagration on offshore platform and personnel is assessed. The hazardous area generated by blowout gas dispersion is mainly distributed on the drill floor. The increase of well productivity can cause an increase of the hazardous area. The minimum radius to ensure the safety under deflagration overpressure is 30.63 m. The present work could help in conducting a prior risk assessment and tomake an emergency response plan.