General Statement

The full 3D characterization of fracture networks is a key issue in naturally fractured reservoir modeling. Fracture geometry (e.g., orientation, size, spacing), fracture scale (e.g., bed-confined fractures, fracture corridors), lateral and vertical variations, need to be defined from limited, generally 1D, data. In order to populate a 3D reservoir model, one needs to define, at the field scale, how the fracture network is distributed in between wells and, at the reservoir cell scale, how the fracture properties can be summarized to fully represent the matrix-fracture flow exchange. With well data only, the problem is clearly undersized and we need to define other sources of information, such as relationships between fracturing at well and large-scale drivers, for example, or derive the missing gap from outcrop data, which provide qualitative concepts or quantitative relationships between fracture parameters. The study presented in this article aims at modeling, at the reservoir cell scale, 3D fracture networks from quarry outcrops. An innovative data collection method is used; this allows a full characterization of the fracture network in 2D, which provides the basic inputs required for the construction of DFN models. In turn, the reality of the fracture network can be compared to the simplification that we make while drilling through these networks and ultimately summarizing them as a double porosity reservoir cell, and some basic lessons can be learned. Data collection Calvisson is located in the Southeast Provence Basin on the western, upthrown, side of the NE-trending Nimes fault. The “Cante Perdrix” quarry is a circa 300x300m working area (i.e.,one or two typical reservoir cells) excavating 30 m of fairly homogeneous, Hauterivian marl