Wettability Alteration of Sandstone by Chemical Treatments

Figure 4

Oil droplets on the surface of the sandstone cores before and after treatment with FG40.

(a) Oil (without chemical treatment, 𝜃=10^∘)

(b) Oil (treated with 0.05% FG40, 𝜃=75^∘)

(c) Oil (treated with 0.1% FG40, 𝜃=88^∘)

(d) Oil (treated with 0.2% FG40, 𝜃=89^∘)

(e) Oil (treated with 0.3% FG40, 𝜃=93^∘)

(f) Oil (treated with 0.5% FG40, 𝜃=84^∘)