How to model realistic 3D Karst reservoirs using a Pseudo-Genetic Methodology - Example of two case studies

Abstract

This paper describes the application of a new pseudo-genetic approach for modeling of karstic aquifers. Two case studies are presented. The first is a karstic aquifer in the Swiss Jura Mountains, which is characterized by a very complex geometry due to tectonics. The second is a synthetic case of a submarine spring in a karstic area in the Mediterranean basin. For both examples, the same methodology has been applied. First, a 3D deterministic model of the regional geology is built, then based on field observations stochastically heterogeneous hydrogeological properties are modeled within the different formations. The analysis of the hydrological conditions helps in defining the type of karstic systems that is expected, the recharge area (that can be diffuse or localized), and the discharge area. Finally, karst conduits are simulated that connect the recharge area to the main discharge area using a shortest path technique based on the 3D simulated distribution of the hydrogeological properties of the geological formations. Doing so, one can obtain equiprobable conduit simulations from the different realizations of the hydrogeological properties. The results of these simulations can then be used to model flow and solute transport.