A Stochastic Workflow for Fault-Seal Characterization in Carbonate-Dominated Reservoirs

Summary For faults hosted in siliciclastic-dominated reservoirs, there are established workflows that have been successfully used to address industry fault-seal characterization problems. These established workflows rely on the observation that clay mineral content of fault rocks in siliciclastic hosts has a strong influence on flow properties, with higher clay contents corresponding to lower permeability and higher capillary threshold pressure. However, fault-seal characterization in carbonate-hosted faults is more complex, partly because the faults typically have low clay contents and partly because of variability due to fracturing, cementation, and diagenesis. As a result, there is no equivalent established workflow for fault-seal characterization in carbonate reservoirs, despite estimates that approximately 60% of the world’s proven oil reserves and 40% of the world’s gas reserves are trapped in those reservoirs. There are several possible mechanisms that could allow carbonate-hosted faults to support significant static hydrocarbon columns or act as baffles to flow on production timescales, and rules to characterize these faults are required. The aim of this presentation is to propose a workflow for fault-seal characterization in these reservoirs, and demonstrate the workflow on a test data set.