Pre-Caspian Basin Carbonate Reservoir - Modelling Fractures of the Platform Interior

Large Carboniferous Fields in the PreCapisn Basin, like Aktote, Karachaganak and Kashagan, consist of carbonate build-up characterized by the presence of biohermal and breccias facies that result to be affected by high productivity sometime largely exceeding the permeability estimated from core samples. This fact has been generally related to the presence of both fractures and, in some cases, karst. These facies generally surround platform interior environment of deposition which is characterized by grainy facies which shows lower productivity, more close to that inferable from the core samples permeability. For this reason the platform interior environment of deposition is considered more homogeneous and targeted as the best reservoir where implementing the gas injection. However some clues suggest that also this environment of deposition could be affected, locally, by the presence of enhanced permeability related to fractures. The target of this paper is the description of the general workflow tested in some studies in order to model the presence of this fracture network and investigate the possible impact on the gas injection.