Coupling fracture facies with in-situ permeability measurements to generate stochastic simulations of tight carbonate aquifer properties: Example from the Lower Cretaceous aquifer, Northern Provence, SE France

Pierre-Olivier Bruna (1) , Yves Guglielmi (1) , Sophie Viseur (2) , Juliette Lamarche (1) , Olivier Bildstein (3, 4)

1 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement
2 CRPG - Centre de Recherches Pétrographiques et Géochimiques
3 LMTE - Laboratoire de Modélisation des Transferts dans l'Environnement
4 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)

The relationships between fracture facies and permeability distribution have been explored using a well-constrained 3D implicit structural model of hemipelagic low porosity/low permeability carbonate from the Northern Provence region, SE France. Fracture and permeability facies were determined using an extensive dataset of 99 hydrogeological wells. Data processing was undertaken using a step-by-step approach, involving: (i) identification of the fracture facies based on well logs detailing structure and stratigraphy; (ii) determination of permeability facies from the a priori correlation between the dimension of the hydraulic radius of influence (deduced from slug test analyses) and the type of reservoir heterogeneity (fissure, fracture, fault zone, etc.); (iii) three dimensional plot of fracture and permeability facies in the geological model using a variographic analysis of data. Thirty-three sequential indicator simulations (SIS) based on geostatistic analyses were realised on both fracture and permeability facies. Finally, a connectivity algorithm was developed to compute the probability of connection between selected infiltration areas and the major aquifer springs via moderate- to high-permeability geological bodies. Key results are: (i) fault zones have a greater role in controlling permeability facies distribution than on fracture facies repartition; (ii) there is little correlation between permeability and fracture facies distributions; (iii) connectivity results highlight the compartmentalisation of aquifers in the Cadarache area, the extensions of permeable geological bodies being limited by the N130 faults.

Keywords: Geostatistics; Slug test; Tight reservoir; Fracture facies; Permeability facies; Carbonates

Domains: Nuclear Theory [nucl-th]; Nuclear Experiment [nucl-ex]

Pierre-Olivier Bruna, Yves Guglielmi, Sophie Viseur, Juliette Lamarche, Olivier Bildstein. Coupling fracture facies with in-situ permeability measurements to generate stochastic simulations of tight carbonate aquifer properties: Example from the Lower Cretaceous aquifer, Northern Provence, SE France. Journal of Hydrology, 2015, 529, pp.737-753. ⟨10.1016/j.jhydrol.2015.08.054⟩. ⟨cea-02382929⟩