Adsorção de tensoativo catiônico para organofilização de argila atapulgita

Abstract

The great challenges coming from well drilling, there was a need to develop or modify fluids whose properties were able to follow drilling requirement. Due this, the study with clays has been developed increasingly since they have properties such as swelling capacity, high ion exchange capacity and also strong adsorption capacity. In order to obtain favorable results, it is necessary to modify the clay so that it plays a fundamental role in the preparation of drilling fluid. Drilling fluids are so important in oil-related activities, since they ensure the cooling and lubricity of the drill bit, the well’s drilled maintaining stability, among other functions. Oil-based drilling fluids have been developed for drilling with high temperature and high-pressure conditions, common aspects in directional drilling, which creates limitation for water-based fluids. The analysis of the rheological behavior of the drilling fluids is too important to determine the best composition and the best treatment to be applied in these fluids to perform tasks in the drilled well. The aim of this work was to modify the attapulgite clay, in order to increase its affinity for the organic phase of oil-based drilling fluids, applying a cationic type surfactant with a pre-established concentration. By the study of the adsorption isotherms, the observed behavior had a great tendency by the Freundlich model. The equilibrium time did not change the degree of clay’s adsorption. The contact angle measurements indicated an increase in the hydrophobic characteristic of the modified attapulgite. In the context of rheological analysis, organophilized attapulgite was very similar to a commercial organophilic clay.