3D stochastic simulation of caves: application to Saint-Sébastien case study (SE, France)

International audienceKarst networks are complex structures that are difficult to observe or survey. However, they have a major impact on fluid flows and water resources as well as on petroleum reservoir behaviour. In such applications, geostatistical approaches are generally used to simulate several 3D models of geological structures, on which risk assessment analyses are performed in terms of reserve assessment or flow behaviour. In this paper, such an approach is proposed to simulate karst networks. The approach is based on the classical method Sequential Indicator Simulation (SIS). It relies on the decomposition of the karst network into conduit families, depending on their orientation and dimensions. Conduit shapes are characterized by variograms and are simulated sequentially from the first to the last family. Conditioning points are randomly simulated to assert the connectivity between each conduit family. Moreover, special attention is paid to the integration of geological and hydrogeological knowledge into the karst network simulation. The proposed approach is applied to the case study of Saint-Sébastien (Gréoux-les-Bains, Provence) to illustrate the possibility of integrating analogues and geological information