Coupled Static/Dynamic Modeling For Improved Uncertainty Handling

Abstract

Abstract In the petroleum industry, history-matched reservoir models are used to aid the field development decision-making process. Traditionally, models have been history-matched by reservoir engineers in the dynamic domain only. Ideally, if any changes are required to static parameters as result of history matching the dynamic model, then these should be reflected directly in the static reservoir model, ensuring consistency between the static and dynamic domain. In addition, static model uncertainties are often not evaluated in the dynamic domain, which can result in the detailed modeling of geological features that have little impact on the dynamic behavior of the reservoir or the resulting development decision. This paper demonstrates a workflow where the reservoir simulator and static modeling package are closely linked to promote a more integrated approach to reservoir model construction, facilitating the interaction between subsurface disciplines. Using either the reservoir simulator or the static modeling package as the platform, the output of the workflow is a sensitivity analysis of the uncertainties related to structure, rock properties, fluids and rock-fluid interactions. Computer-assisted history matching methods (i.e. adjoint-based and Design of Experiments) are used to find the parameter values that result in a history match model. The workflow is described for both a synthetic model and also a reservoir model from a real field case. This methodology results in improved history-matched models and a better understanding of the static and dynamic subsurface uncertainties and their importance, leading to more informed decision-making. Furthermore, it is anticipated that it will result in faster accomplishment of the history matching studies. The method presented here can significantly enhance the understanding of the impact of both static and dynamic subsurface uncertainties on development decisions. In addition, it offers a platform where all subsurface professionals involved in reservoir model construction and simulation can more optimally focus their efforts on improving the integrated understanding of their reservoirs.