SYNTHESIS AND EVALUATION OF C02 PHILIC S URFACT ANTS FOR C02 MOBILITY CONTROL FOR EOR APPLICATIONS

The drop in IFT is associated with the triple tailed surfactant possessing
short branches. carbonyl groups and methyl groups at the tail portion of the surfactant.
It provides suitable sites for C02 to interact intermolecularly with the surfactant.
The foam stability of the surfactants which lowered the IFT to less than 10 mN/m
were evaluated. Triple tailed surfactant possess the most stable foam (20 mins)
compared to the twin tailed surfactant (18 minutes) and single tailed surfactant at 13
mins. Commercial surfactants AOS and DuPont FS50 have foam stability at 5 and 10
minutes respectively at 90°C and in the presence of oil. The MRF values reflect the
same trend as IFT lowering and foam stability. Three tailed surfactant has the largest
MRF of 3.4, the twin tailed at 3.3 and the single tailed at 2.93. AOS and DuPont
FS50 MRF was 1.3 and 2.5 respectively. It appears that the surfactant having
structure which demonstrates favourable C02 affinity has the largest IFT reduction,
highest foam stability and MRF values.