Natural fractures prediction in a lacustrine carbonate reservoir integrating 3D structural restoration and seismic AVAz techniques

Low permeability carbonate reservoirs constitutes significant reserves of oil and gas for Petrobras’ E&P sector. Micro-porosities above ~ 10% in these sedimentary sequences allow the accumulation of significant volumes of hydrocarbon. However, the predominance of pore throats smaller than 10 microns produces low permeability in this type of rock, making it difficult for the flow of interstitial fluid during production. This constitutes the main challenge for making production feasible. The shortage of static and dynamic data in most reservoirs of low permeability makes it extremely difficult to understand the spatial distribution of the different scales of heterogeneities and, consequently, influence in obtaining realistic flow scenarios. In this work, an integrated supervised methodology is proposed for the characterization of natural fractures in a low permeability lacustrine carbonate reservoir in Santos basin, Southeastern Brazilian margin. To achieve the objectives of the study, a workflow was developed that involves the actions, briefly described below: (i) descriptive and kinematic analysis at multiple scales of the brittle structures; (ii) understanding of lithological control in the deformation process; (iii) quantification of the deformation in different phases of movement by 2D / 3D structural restoration techniques and (iv) analysis of seismic anisotropy.