ABSTRACTA comprehensive series of experiments on foaming of two (2) types of crude oil and four (4) types of synthesized Gemini silicone- amine base defoamer in simulated produced water system containing foam surfactant Foam Assisted-Water Alternating Gas (FAWAG) package were investigated under the influence of column temperature at 30 – 60 °C, applied pressure of 1 – 4 bar, and fixed fluid flowrate of 0.5 L/min. In this study, the presence of high saturates composition in the crude oil which at 45 – 75.8 % influence the foam stability of the fluids. This reflects the waxy types of crude oils with higher density properties of 0.8768 – 0.858 Kg/L and increase concentration of foam surfactant from 30% to 90% in the produced water system influences the foaming stability. The microscopic observation shows that bigger bubble size about the average of 400 – 500 µm would slows down the liquid drainage, resulting in foam stability behavior. Defoamers with various structures ranged from amine short-chain, amine long-chain, amine branched-chain and amide-chain were analysed to determine the effect of molecular structure at various concentration from 5 – 40ppm. The defoaming ability was determined by foam height and collapse time. The amide short-chain and amine branched –chain had excellent foam breaking performance which was observed from the mean bubble size reduction to 50 – 100 µm resulting from formation of unstable bridge across lamellae causing the foam to rupture, allowing faster liquid drainage, thus improving suppression performance.
