Enhancing Understanding of Highly Fractured Carbonate Reservoirs through Multi-Scale Characterization and Modeling

This study focuses on the critical significance of reservoir characterization in highly fractured carbonate reservoirs in the Middle East, which comprise major global oil reserves. Considering the intrinsic challenges of high heterogeneity and fracture complexity, understanding the reservoir’s behavior is crucial for predicting production dynamics and managing early gas and/or water breakthroughs. This study approach involves an integrated analysis: incorporating core data, well bore image interpretation, well tests, dynamic data, and seismic interpretation. The resulting detailed characterization of this mature carbonate reservoir reveals a reservoir with abundant vugs, breccia, and a high density of vertical fractures. The construction of a 3D geological model identifies three distinct fracture sets influencing reservoir quality and behavior: (1) fractures associated with collapse cavities and vugs, (2) fractures related to folding, and (3) fractures influenced by stress. A correlation between fracture characteristics and production performance was found, contributing to a more comprehensive understanding of the reservoir and providing valuable insights for future field decisions.