Uji Screening Thermal Stability Dan Phase Behavior Pada Kombinasi Surfaktan Nonionik Dan Amfoter

The current demand for oil and gas in Indonesia is always increasing, inversely proportional to the production trend which continues to decline. One of the EOR methods, namely chemical injection, especially surfactant injection, can be used as a solution to increase oil recovery in mature fields. However, to determine the suitability of surfactants to the oil field, it is necessary to carry out laboratory screening tests. In this study, the screening was carried out with the parameters of the thermal stability and phase behavior test through the experimental research method. This thermal stability test aims to determine the resistance and stability of the surfactant at temperature of 60 °C and the phase behavior test to determine the type of microemulsion formed on the combined surfactant with several concentration variation. The results of thermal stability observations for 7 surfactant samples are 1:1 (0,5 %), 1:1 (1 %), 1;1 (1,5 %), 1:1 (2 %), 1:2 (0,5%), 1:2 (1 %), and 1:2 (1,5 %) only sample ratios of 1:2 at all concentrations were stable to the test temperature which resulted in a clear and homogeneous solution. While at a ratio of 1:1 for all concentrations of the resulting solution is cloudy and there is a precipitate. The results of phase behavior observations for samples 1:2 (0.5 %), 1:2 (1 %), and 1:2 (1,5%) the emulsion was in the lower phase from the first day of observation and the emulsion was still in the lower phase or Winsor I persisted like that for up to 168 hours of observation. And it can be concluded that the eligible samples for the next screening test are 1:2 (0,5 %), 1:2 (1 %), and 1:2 (1,5%)