PEREIRA, I. D. S.; http://lattes.cnpq.br/3576322095398237; PEREIRA, Ivna Daniele Souza.
Abstract:
In Paraíba's large occurrences of non-metallic minerals mainly of bentonite
clays, ball clays, kaolin, feldspar, quartz, limestone and mica. Recently
discovered new deposits of clays in the city of Sossego, providing an expected
expansion of mineral inputs in the region. This work aims to characterize
physical, mineralogical and technologically smectite clays Municipality Sossego,
PB, Brazil, for use in drilling fluids. For both, the clays were processed and
characterized by the following techniques: laser granulometry (AG), X-ray
diffraction (XRD), chemical analysis (EDX), cation exchange capacity (CEC),
thermogravimetric analysis (TG) and differential thermal analysis (DTA). The
clays were then transformed into sodic by treatment with sodium carbonate
(Na2CO3), sodium hexametaphosphate (NaPO3) 6 in levels: 75, 100, 125 and
150meq / 100g of dry clay, and being activated with combinations (Na2CO3) and
magnesium oxide (MgO), then held up the study of the rheological behavior of
the dispersions in order to determine apparent viscosity (VA), plastic viscosity
(PV), filtrate volume and pH. The results showed that the clays of smectite were
formed, kaolinite and quartz, with MgO and CaO contents, showing that
bentonites are polycationic. Regarding the use of clays as viscosity agent for
drilling fluids, it was observed that the samples activated with Na2CO3 AM2
partially met the necessary for use in water based drilling fluids specifications.
As for the sample activated to (NaPO3)6 did not develop improvement in
rheological characteristic, then its use as drilling fluid is not feasible. The
combination of Na2CO3 and MgO produced an improvement in the properties
of the produced fluids, proving to be applicable in drilling wells
Keywords: bentonite, rheology, characterization, drilling fluids.