The industry has recognized that dynamic reservoir characterization, from wellbore pressure to production behaviors, is a key driver for maximizing production and recovery. Accurate simulation requires appropriate modeling of the existing heterogeneities in the field.
Most of the main fields around the world produce from naturally fractured vuggy reservoirs, in which matrix, fracture network, and high vuggy porosity are usually present. The effects of vugs on permeability is related to their connectivity. Also, some fractured reservoirs exhibit a fractal behavior, which describes fractures with different scales, poor fracture connectivity and disorderly spatial distribution. The behaviors of both fractured-vuggy and fractal reservoirs cannot be explained by the conventional dual-porosity model.
This lecture addresses the above characterization approaches and reviews field applications using pressure transient and rate data. It also presents the current and a future vision for an appropriate dynamic characterization of these reservoirs.