Due to challenges encountered in drilling wells, there is a need to develop fluids that have properties suitable and able to meet all the requirements of drilling, such as, high capacity for carrying of solid and high lubricity. Besides that, they need to be environmentally friend. The degree of impact of drilling fluids in the environment depends on the type of fluid used, if water or oil or synthetic or air based. It is therefore of fundamental importance to develop fluid with specific characteristics in each stage of drilling. Thus, the aim of this work is to develop aqueous fluids with low content of solids and rheological, filtration and lubricity properties adjusted for drilling of onshore oil wells. The fluids were formulated by using industrialized sodium bentonite, polymeric additives and lubricants, in different concentrations, in its composition. Rheological, filtration and lubricity studies showed that the fluids have pseudoplastic behavior and, the selected additives successively play their functions of rheological modifiers, filtrate reducer and lubricant agent. Moreover, it was evidenced the necessity oflubricant additives in aqueous fluids containing bentonite clay and polymers. The addition of 1% of lubricant in the fluid is sufficient to adjust the lubricant capacity of fluids.
clays; polymers; lubricants; aqueous drilling fluids
