[en] The mixture oil/water occurs in the operations of production, transportation and refining, as well as during the use of its derivatives in the petroleum industry. This kind of water turns into a problem of how to be purified, and how to improve its quality. Researchers have been developed in order to find out water/oil separation processes that will be cheaper and more effective. One of the processes has been the use of organophilic clay utilized as a solver. This project studied two organophilic clays, Brasgel clay PA (sodic activated) and silt clay, which passed through a process of cation exchange with quaternary salt of ammonium cethyltrimethylammonium bromide by direct method. The samples were characterized by X-ray diffraction (XRD), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM) and Foster's swelling in petroleum derivative. Foster's swelling was carried out with and without agitation in gasoline, diesel, toluene and lubricating oil. The results indicated the samples was organophilic materials, with improved efficiency of Brasgel clay in gasoline and diesel and when compared to silt clay in the test of capacity for adsorption and Foster's swelling, the results were similar to kerosene and lubricating oil. (author)