Comparison of the 1FT of alkali/surfactant and branched alcohol/surfactant for Surfactant Flooding

Surfactant flooding has been applied commercially for many years, especially in the 1970's
and 1980's. The principle oflowering the interfacial tension to release residual oil trapped
thus giving a higher oil production. The ultimate challenges in using surfactant as the
preferable methods in chemical EOR are the effectiveness of the surfactant and the cost of
using surfactant. Researchers have shown additives (e.g.; Alkaline and Branched Alcohol)
incorporated with surfactant enhanced the effects of surfactant. These additives can also
provide solution to the problems in the reservoir like the effective concentrations of
surfactant needed, level of tolerance of surfactant in high salinity, high hardness and high
temperature reservoirs and preventing the loss into the rock. This project was undertaken to
compare the effects of alkali and branched alcohol on surfactant flooding.
Interfacial tension is one of the important criteria in determining the success of EOR.
Interfacial tension values of the surfactant with additives were measured using Interfacial
Tension Meter (OPMAN 1FT 700). Comparisons were done to show which additives
(alkalis; sodium carbonate and sodium hydroxide or branched alcohold; 2-methyl-lbutanol,
2-methyl-2butanol) were better and at which concentrations (0.1, 0.25, 0.5, 1.0 wt %). At
reservoir condition, pressure ranged between 1 000-1800psi with the temperature of 40-45 °C
was used. Moreover, physical appearance (precipitation) in hard and soft water was also
been observed. Results showed that branched alcohol performed well with surfactant in high
salinity water with no precipitation effect and had a very low interfacial tension down to
O.SmN/m. However, further branching in alcohol did not show much effect on 1FT.
Compared to alkali, some precipitation occurred due to reaction of sodium with hydroxide
and carbonate ions.