Experimental study of the effects of surfactant material and hydrocarbon agent on foam stability with the approach of enhanced oil recovery

Abstract

Injecting foam into hydrocarbon reservoirs in order to transport the fluid is amongst the novel methods for enhanced oil recovery (EOR). Stability of foam is the main challenge to successful usage of it in EOR. One of the challenges of using foam in oil recovery is to maintain its stability in the face of the oil phase. So, it is required that before using foam in the processes of enhancing the recovery, the properties of foam and its mutual behavior toward the oil be known. Therefore, by making two different experimental setups in this study, the effect of changing the properties of four surfactants (CAPB and three selected surfactants in past research (SDS, CTAB, AOS)) and four oil phases on foam stability have been studied. In the experiments of bulk scale, foam has been produced by distributing the air into a vertical column containing surfactant solution. The experimental setup built in bubble scale is composed of one transparent Hele-Shaw cell. By computer processing of recorded images captured by a camera, the evolutionary process of foam has been studied qualitatively and quantitatively.The results showed that the surfactant type had a significant effect on the stability of foam. First, the SDS and CAPB has better stability in the presence and absence of oil respectively. However, by combining of 1:1 ratio of SDS and CAPB, the foam stability has been improved significantly. The half-life time of new foam (CAPBSDS) Comparing to CAPB foam was increased in the absence of oil at the bulk and the bubble scales respectively by 33% and 122%. However, the stability of all the foams in the presence of the oil phase decreased, but CAPBSDS showed the best resistant and improve half life time comparing to SDS by 71% at the bulk scale. In addition, by comparing the obtained experimental results with the classical theory, inability of the theory in predicting the value and order of the foams stability has been observed.