Investigating Reservoir History Matching through the Geomechanical Analysis of Karstified Features in Brazilian Pre-Salt Reservoirs

ABSTRACT: The Brazilian Pre-Salt reservoirs, characterized by their fractured and karstified nature, pose significant challenges in exploration and production. Key properties such as Young's modulus and rock compressibility are critical yet difficult to characterize in Reservoir Geomechanics. While pore compressibility is essential for flow simulation, it often remains constant in models, despite the fractured system's compressibility being notably higher than that of the rock matrix. Limited literature exists on karst compressibility, necessitating differentiation from fracture compressibility. (Maria, 2022) proposed a new method to evaluate the compressibility of diffuse karst features, based on (Dobrynin, 1970) approach. This study aims to implement these techniques for history matching in a Pre-Salt field, utilizing a pseudo-coupling method to incorporate geomechanical effects. The results will enhance the understanding of reservoir heterogeneity, considering both rock matrix facies and karst forms. This methodology will aid PETROBRAS in addressing the specific challenges of the Pre-Salt Fields, optimizing production, and improving predictive reservoir models, with potential applications to other global karstified reservoirs.