Vuggy carbonates are an important pore class for carbonate oil reservoirs. The determination of fluid flow properties like relative permeability from laboratory core floods in not trivial for this heterogeneous type of material. In many cases unusual responses have been observed, showing that several basic assumptions used for the interpretation of laboratory core floods are violated for vuggy material. Since the fluid properties can be attributed to the internal structure of the material it is important to highlight rock characterization. The local vug-matrix heterogeneity and connectivity of vuggs leads also to question about representative elementary volume for petrophysical and fluid flow properties. We focus in this paper on vuggy carbonate rock characterization based on Nuclear Magnetic Resonance (NMR), Micro Computed Tomography (µCT) and Computed Tomography (CT) measurements.
The objectives of the research have been to establish a basis for estimates of fluid flow and oil recovery efficiency in vuggy carbonate rocks.