Two Approaches for Integrated Uncertainty Study Applied on a Field Case - Full Monte-Carlo vs Light-Up

Nowadays integrated uncertainty studies have become a necessary step of any reservoir development project. The main challenge is then not to evaluate the uncertainty for a particular variable but to integrate the uncertainties of all variables and all modelling steps. Despite the advantages of full Monte-Carlo approach and the increasing computation power there are still the limits of applying globally this approach from the seismic up to the dynamic simulation. For this purpose different approaches were designed, combining screening results, Experimental Design and Monte-Carlo methods (Milliken et al. 2008; Li et al. 2010). In this paper we compare two approaches of integrated uncertainty study applied to a real case study. Both consist of three main steps: structural, geological and dynamic uncertainties with stepwise integration of uncertainties. The first method evaluates geological uncertainty with a full Monte-Carlo method; the second is based on the mono-parameter sensitivity study and its impacts combination by scalar Monte-Carlo method. For both approaches structural and dynamic uncertainties are evaluated using the same workflows. The comparison is twofold: firstly on static volume, secondly on the transfer of the static uncertainty to the dynamic part.