Saturation of Reservoir Rocks
Fluid Saturation of Reservoir Rocks The concept of fluid saturation can be explained through a glass filled with different fluids (Figure 5.1). Figure 5.1a shows a glass filled entirely with water, meaning that the entire pore volume (glass volume) is occupied by water and thus the water saturation is 100%. Fluid saturation is the volume of a particular fluid in a rock sample divided by the pore volume. In Figure 5.1b, an identical glass is occupied by both water and oil. Here, the water saturation cannot be 100% as the oil is sharing some space with the water. Finally, Figure 5.1c has water, oil, and gas in the same glass, and thus the saturation of each fluid will be less than 100%. Figure 5.1: Schematic showing identical glasses filled with different fluids: (a) the glass is filled with 100% water, representing S w = 1, (b) the glass is filled with 50% water and 50% oil, representing S w = 0.5 and S o = 0.5, and (c) the glass is filled with 50% water, 30% oil, and 20% air (gas), ...