Exploratory Approach to Fractured Reservoir - A Case Study In a Brazilian Field

The investigation and prediction of fractured systems for the analysis of non-conventional reservoirs are considered challenging tasks for geoscientists and engineers because data directly related to fractures (mainly image logs and cores) are scarce. During exploratory phases, fracture evaluation is even more critical because, quite often, few or no wells are available. This work, conducted during the exploration phase, is focused on the evaluation of a fractured Albian carbonate oilfield, located at the Campos Basin, in Eastern Brazilian continental margin. Using a limited number of wells, this study aimed to understand the lithological, diagenetic and mechanical controls of fracture distribution and their relationship with faults and salt domes mapped on seismic data. The workflow was as following: 1) structural mapping and modeling; 2) interpretation and structural analysis of fractures from image logs; 3) 2D finite element modeling; 4) correlation with elastic properties. Geometric and kinematic analyses, besides the structural evolution carried on in this study, were fundamental to the correlation between fracturing and regional deformation. The importance of a conceptual structural geologic model, especially in cases where it is not possible to perform a 3D numerical model of fractures, such as DFN’s and others, is highlighted in this work.