Quantification of Uncertainty in CFD Simulation of Accidental Gas Release for O & G Quantitative Risk Assessment

Abstract

Quantitative Risk Assessment (QRA) of Oil & Gas installations implies modeling accidents’ evolution. Computational Fluid Dynamics (CFD) is one way to do this, and off-the-shelf tools are available, such as FLACS developed by Gexcon US and KFX developed by DNV-GL. A recent model based on ANSYS Fluent, named SBAM (Source Box Accident Model) was proposed by the SEADOG lab at Politecnico di Torino. In this work, we address one major concern related to the use of CFD tools for accident simulation, which is the relevant computational demand that limits the number of simulations that can be performed. This brings with it the challenge of quantifying the uncertainty of the results obtained, which requires performing a large number of simulations. Here we propose a procedure for the Uncertainty Quantification (UQ) of FLACX, KFX and SBAM, and show its performance considering an accidental high-pressure methane release scenario in a realistic offshore Oil & Gas (O & G) platform deck. The novelty of the work is that the UQ of the CFD models, which is performed relying on well-consolidated approaches such as the Grid Convergence Index (GCI) method and a generalization of Richardson’s extrapolation, is originally propagated to a set of risk measures that can be used to support the decision-making process to prevent/mitigate accidental scenarios.

Automated Shape and Process Parameter Optimization for Scaling Up Geometrically Non-Similar Bioreactors

“…In order to quantify the discretization error for the new geometry and to ensure an economic implementation with regard to the 100 optimization simulations, a mesh study was carried out. For this study, the grid convergence index (GCI) method was used as described in Baker et al [77], Ramírez et al [78] and Pappalardo et al [79]. The standard value of 1.25 was chosen as the safety factor F S [23,26].…”

Improvement of HEK293 Cell Growth by Adapting Hydrodynamic Stress and Predicting Cell Aggregate Size Distribution

“…This method is considered to be the best practice and is recommended by the OECD [ 77 ]. A detailed explanation of the procedure can be found in [ 78 , 79 , 80 ]. Five computational meshes with 0.28 to 2.09 were created for the studies, resulting in 3 GCI cases ( Table 2 ).…”

Guest Editorial: Special Issue of ESREL2020 PSAM15

“…The first paper in this Special Issue by Fabrizio Pappalardo, Alberto Moscatello, Gianmario Ledda, Anna Chiara Uggenti, Raffaella Gerboni, Andrea Carpignano, Francesco Di Maio, Riccardo Mereu, and Enrico Zio presents a Quantitative Risk Assessment (QRA) of Oil and Gas installations by Computational Fluid Dynamics (CFD) tools [1]. This work aims to handle a major concern related to the use of CFD tools for simulating accidents.…”