Influência da adição de minerais de diferentes naturezas químicas no desempenho de fluidos olefínicos.

Abstract

During well drilling, mineral particles from geological formations are pertinently added to the drilling fluids, which can change their properties, affecting their performance. Thus, the present work aimed to evaluate the influence of the addition of minerals of different chemical natures (bentonite clay, silica, carbonate and halite) on the properties of olefinic fluids used in offshore oil well drilling. For this purpose, olefinic drilling fluids were prepared and mineral particles of bentonite clay, silica, carbonate and halite were added to them in a volumetric proportion of 5%. The fluids were characterized by density tests, rheological behavior, gravitational separation (bottle test), HPHT filtrate volume, electrical stability and optical microscopy, before and after the dynamic thermal aging process. The results showed that among the evaluated minerals, the addition of halite provided a negative influence on the fluid properties, compromising its performance. On the other hand, the addition of other minerals (clay, silica and carbonate) improved the rheological properties and fluid stability. In particular, the addition of bentonite clay promoted a more expressive positive effect on the fluid behavior.