Liquid based defoamers are used to prevent foam formation in oil field jobs. Application of these oil field defoaming agents can be noticed during drilling job. It contains elements like surfactants, emulsifiers and silicon based polymers that together work to prevent generation of foam during extraction of oil from mines. Defoamers are directly applied to the surface of oil in order to break down the surface tension of the oil. As its result, possibility of formation of foam decreases.