Estudo dos efeitos da contaminação por argila e Ca(OH)2 em um fluido aquoso salgado tratado com polímeros

• Autor(a) principal: Albuquerque, Heraldo da Silva
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/39532
• topic: Fluidos de perfuração aquosos; contaminação; argila; hidróxido de cálcio.; water base mud; contamination; clay; calcium hydroxide.; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA

During the drilling of oil wells are generally found difficulties when going through layers of rock known as shale. These, in turn, have normally in its composition, a percentage of clay, which, in many situations, are reactive, and may be slightly, medium and high reactivity due to its hydration in the presence of water. The aqueous fluids, usually, have more difficulties with regard to the inhibition of these clays of the fluids non-aqueous. These clays hydration, expanding, and may decrease in the diameter of the well (obstruction of the annular), stuck pipe, wellbore erosion, collapse and increase diameter of the well and hole enlargement. Another problem normally encountered is the contamination of the water base mud by cement during cementation of casings and of cement plug. The calcium hydroxide Ca(OH)2 present in the composition of the cement can generate serious problems for the properties of the fluid drilling, such as: increased pH, an increase filtration, apparent viscosity, gels, yeld point and calcium . This work studied the effects of contamination by clay and by Ca(OH)2 in a water base mud salt (NaCl) treated with polymers. The results obtained showed variations in the properties (viscosity, fluid loss, pH, alkalinity and Methylene Blue Test (MBT)) of the mud. The mud contaminated with clay, when compared with the original mud, without contaminants, showed no significant changes in the rheology, showing that the inhibitors acted effectively. The MBT increased caused by presence clay. There was a small reduction in the fluid loss due the clay have helped in this control. The mud contaminated with calcium hydroxide showed variations in more properties (pH, rheology, fluid loss and alkalinity) due to dissociation of ion Ca2+ present in the Ca(OH)2 in aqueous phase, result an ionic exchange with ion Na+ present in the carboxymethilcellulose (CMC). The mud studied can be applied in drilling that contain areas of shale which cause collapse and/or stability wellbore. The application of this mud generate high penetration rate (ROP) and the attainment of goods caliper of the well.