INFLUÊNCIA DE SAIS DE POTÁSSIO COMO INIBIDORES DE INCHAMENTO DE FOLHELHOS NO DESEMPENHO DE FLUIDOS DE PERFURAÇÃO POLIMÉRICOS

Stability of well in layer with shale is strongly influenced by the kind of drilling fluid used in the drilling activity. Therefore, when its praticle the use of aqueous fluids, then it is need to use swelling inhibitors to avoid the expansion of such formations shows in water presence. Actually, new products chlorine-free has been tested due to enviroment concern. Thus, the aim of this work is to evaluate the influence of chlorine-free inhibitors in the rheological and filtration properties and polymeric drilling fluid toxicity with the potential to be applied in drilling oil wells that have reactive-formations. From the evaluation of the results, it was verified that the fluids developed with chlorine-free inhibitors showed different rheological and filtration properties. This behavior is related to the different dosages of K+ ion (the potassium ion promotes the control of the swelling reaction formations) present in the studied fluids. The results also indicated that all fluids are non-toxic.