OOIP. The total oil recovery from the first cycle was 9% of the OOIP. The first 1 PV of injected foam extracted 6% OOIP due to improvement in sweep efficiency compared with water flooding the core bearing heavy oil. The 0.5 PV of SW encountered a free bank of oil released after the foam was injected. However, the first cycle of foam and d2SW flooded into core B35 produced 10.8% of the OOIP. The lower injected brine salinity provided more oil recovery than SW, which can be ascribed to wettability alteration, as discussed later in the contact angle section. The first cycle of foam and d10SW in the core B45 caused an increase in the tertiary recovery up to 12.45% of the OOIP, which was higher than the two previous experiments. The d10SW salinity is 4830 ppm (see Table ). The high oil recovery improvement was due to the wettability alteration towards being more water-wet.