Purification of Bentonite Clays from the District of Cubati, PB, for Obtainment of Organoclays for Use in Drilling Fluids

Abstract

The main deposits of bentonite clays are located in the district of Boa Vista, in the State of Paraiba, Brazil. The random exploration of these deposits for many years is causing the clays to be depleted, and this will turn into a serious problem to the national petroleum industry. So, this work aims to study the characterization of new deposits of bentonite clays in the district of Cubati, in the State of Paraiba, Brazil, with the objective of developing purified organoclays, using a hydrocyclone, from ionic and non-ionic surfactants for use in drilling fluids. The characterization of the studied clay samples was done by applying the following techniques: granulometric analysis by laser diffraction (GA), X-ray diffraction (XRD) and chemical analysis by X-ray fluorescence (EDX) and thermogravimetric (TGA) and differential thermogravimetric (DTA) analysis. The characterization is typical of bentonites and the dispersions present rheological properties which meet Petrobras’ specifications for diesel oil media, organofilized with Praepagen WB.

Influence of the purification of bentonite clay from new deposits in the state of Paraíba-Brazil for use in water-based drilling fluids

“…The samples having the highest percentage with diameter larger than 20 µm were AM4 (4.98%) and AM1 (3.75%). These results were similar to those described in [30][31][32][33]. Processing the samples in the centrifuge increased the concentration of the portion of clay having D<2 μm with respect to the natural samples by the following amounts: 228% (AM1), 402% (AM2), 297% (AM3), and 370% (AM4).…”

Technological Evaluation of Cubati/Brazil Montmorillonite / Avaliação Tecnológica Da Montmorillonita De Cubati/Brasil

“…Due to its polycationic feature, with regard to the application as a drilling fluid, it is necessary to promote its activation with sodium carbonate, since sodium montmorillonite presents a greater volume expansion when in contact with water, producing gel aspect [47], increasing the clay mineral interplanar distance in order to allow greater efficiency of its use. Compared to the literature [37,43,44,45,46], silica and alumina percentages of the studied sample were lower, while magnesium, calcium and iron oxides content were higher. This fact can be associated to the increase in isomorphic substitutions at studied sample octahedral sites due to the presence of iron in kaolinite structure, while higher contents of magnesium and calcium are explained to the presence of carbonates.…”

“…Besides that, there is the presence of illite in both natural and glycolated samples. Similar results were found by [37,43,44,45,46], in which the main minerals found in bentonite clays from the same region were montmorillonite and kaolinite. composition rich in silica (SiO2) and alumina (Al2O3), as well as significant levels of magnesium, typical of this clay minerals.…”