Institute of Petroleum Engineering

Project: Fractured Reservoir (FR)

Description of naturally fractured reservoirs, combined with the knowledge of the physics of multi-phase flow provide the basis for understanding and forecasting the performance of these reservoirs.  Recent advances in understanding of major forces (capillary and gravity, particularly when gravity drainage is the dominant mechanism) have contributed significantly to describing the flow in fractured porous media.  However, the knowledge of main pertinent fracture parameters, that is, fracture capillary pressure (Pcf) and fracture relative permeability (krf), which affect flow in fractures and its interaction with blocks, is still associated with major uncertainties.

Naturally fractured reservoirs contain a significant portion of the world’s oil reserves which also represent a significant geological storage potential for CO2 as a means of greenhouse gas reduction.  Geological CO2 storage in oil reservoirs, are most likely target for CO2 mitigation practices because of a number of reasons including additional economic benefit through EOR, existence of abundant characterisation data and utilising at least part of the existing infrastructure.

Despite a significant amount of research carried out on CO2 injection, the understandings of the interactions between CO2 and oil in fractured reservoir is at its early stages. Effects of diffusion and dispersion of CO2-gas from fractures into the matrix and the subsequent flow of oil from the matrix into surrounding fractures are important outstanding issues.