Estudo reológico de um fluido de perfuração à base n-parafina, utilizando argila modificada com tensoativo

• Ano de defesa: 2015
• Autor(a) principal: Cunha Filho, Fernando José Vieira da
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA QUÍMICA
• Palavras-chave em Português: Fluidos de perfuração; Fluido base óleo; Tensoativos; Organofilização; Estudo estatístico; Reologia; CNPQ::ENGENHARIAS::ENGENHARIA QUIMICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/20414

For drilling of oil wells, one of the stages of oil and gas is of utmost importance to use the drilling fluid. Among the existing drilling fluids, the oil-based drilling fluids are used in situations which require higher strength at elevated temperatures, low corrosion rate, low solubility of the salt formations, such as those found in the perforations of the pre Layer-salt. This work aimed to study rheological, attracts STATISTICA 10 a drilling fluid, produced from a microemulsion system, using a clay (bentonite) organophilizated. The fluid was studied consisting of n-paraffin as oil phase, brine (35g / L NaCl), surfactant nonilfenoletoxilado with four degrees of ethoxylation and barytes as density modifier to give weight to the fluid and reach the weight 8.5 lb / gal, usually used in drilling and standard in this work. The experimental procedure was divided into six steps: organophilization process of bentonite, which was carried out the surface of the clay modified by the cationic surfactant hexadecyltrim ethylammonium bromide (CTAB) at three different concentrations: 30% above the critical micelle concentration (cmc); 30% below the critical micelle concentration (CMC); the critical micelle concentration (c.m.c); Analysis of surface tension and wettability, to assess the success of surface modification; Construction of ternary phase diagrams in order to obtain the microemulsion systems; preparation of drilling fluid; factorial design, to statistical study using STATISTICA software 10.0; and rheological analysis at three different temperatures: 25 °C, 45 °C and 65 °C. The variable responses obtained after rheological testing were: plastic viscosity, apparent viscosity, yield stress and thixotropy. It was noticed increased wettability by decreasing the contact angle, as larger amounts of quaternary ammonium cations were adsorbed onto the clay surface. In addition, statistical analyzes have provided model equations to represent the response variables as a function of control variables significant for medium and predictive studied intervals.