This invention is directed to a method for defoaming crude oil by the addition of copolymers based on silicone free alkyl acrylics defoamers for crude oils with densities between 10 and 40° API. The alkyl acrylic copolymers at conditions similar to those of gas-liquid separators are efficient foam formation inhibitors in heavy and super-heavy crude oils to reduce foam levels between 15 and 50% faster than non-dosed crude oil. Some acrylic copolymers exhibited a greater efficiency as defoamers than commercial silicones, which promote the defoaming only 20 or 25 vol % faster than the natural foam collapse. Silicones as defoamers present serious problems as the formation of deposits and the deactivation of catalysts in the refining processes. These problems have originated a series of interdictions to use silicon based defoamers and new chemical compounds completely silicon free are required to control the foam levels in the gas/petroleum separation tanks.