The main bentonite reservs in Brazil are located in Boa Vista, PB. In order on widening the reserves, on the mineral production and on the consolidation of the state as the largest producer in the country, many studies have been carried out by UFCG on the clays recently discovered in the Districts of Cubati and Pedra Lavrada. This work is intended for the characterization of new deposits, for the development of natural and organofilic clays, which will be employed in oil-based drilling fluids. The characterization of the clay was done by means of the following techniques: GA, XRD, EDX, TG and TGA. For purification, a hydrocyclone was used, and in the organofilization process, the Praepagen-WB surfactant was used, in three proportions. The results suggest that the characterization is typical of bentonite. The purification process proved to be efficient and the rheological study revealed that just one of the clays is suitable for application in oil-based drilling fluids.

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.

Foster swelling is one of the methods used to determine the compatibility between organoclays and organic dispersant media, improving the quality of organoclays. The need for replacing imported clays by national ones for the oil industry has recently resulted in the discovery of new deposits of smectites in the cites of Cubati and Pedra Lavrada, PB, reflecting great social and economic effects for that region. So, the objective of this work is to obtain organoclays from smectites from Pedra Lavrada, PB, aiming at the study of how to make these clays suitable with some organic dispersant media through Foster swelling. After organofilization, the clays were characterized by X-ray diffraction and Foster swelling. The results pointed that some media are compatible with organoclays, being diesel, kerosene and varsol the descendant order of compatibility between the clays and the organic media.

The organoclays are derived from bentonite clays treated in aqueous solution with surfactants, which are incorporated into the interlayer surface of clays, covering them with an organic layer; so, the naturally hydrophilic clay becomes hydrophobic. This paper proposes a study to find the dispersant media (diesel, paraffin or ester) which is more suitable for use in fluids, using the bentonite clay Cloisite Na +, treated with ionic surfactants Praepagen HY and Praepagen WB. The organoclay obtained was characterized by X-ray diffraction, and we measured the apparent viscosity and plastic dispersions. We observed the importance of the type of surfactant and dispersant amid to obtain organoclays for non-aqueous drilling fluids with the dispersants that meet existing specifications for drilling oil wells.

The state of Paraíba disposes of one of the largest deposits of smectites in the country. However, these smectites present in their composition elevated contents of accessory minerals, especially quartz. For these clays to become viable to determine technological use it is necessary the elimination of part of these minerals. The particle size analysis of a soil consists in the determination of the size of the particles that constitute it and their distribution in certain intervals. This work aims to study smectite clays from the city of Pedra Lavrada-PB, through the particle size analyses, for the use in water based drilling fluids. The determination of particle size was made by sieving and laser granulometer. Apparent and plastic viscosities were measured from the samples. The clays were left at rest before the test for periods of 7 and 28 days, with and without deflocculant. It was verified that there was no significant difference in the particle sizes in relation to the resting time of the samples.