Modificações de propriedades reológicas de esmecititas sódicas por tratamento térmico.

Abstract

This dissertation was developed on three selected smectite clays, from Bravo, District of Boa Vista, Campina Grande - Paraiba, which were identified as red, dark green and "bofe" clays. Previous studies of these clays showed special rheological characteristics. So, these clays were choice and, in form of dispersion, had been submitted to thermal treatment with purpose to verify the influence on its rheological characteristic in order to be used as tixotropic fluids for perfuration of oil well. It's used three thermal treatment processes. At two of them it's investigated the dialysis effect before and after the thermal treatment. Also had been determinated for all thermal treatment processes the quantity of carbonates and bicarbonates contained at the suspension. A statistical analysis was perfomed between the rheological properties (apparent and plastic viscosities, and filtrate volume) through simple, logarithm , exponential and powers linear regressions. The studies showed that the red clay type has excellent rheological properties after thermal treatment and it's adequated to be used in the oil well drilling. The dark green clay type showed an improvement at the rheological properties after thermal treatment, however, only the sample submitted to thermal treatment following by dialysis showed results accordine to " Petrobras " specifications (1968). The " bofe" clay type exhibit small sensibillity after thermal treatment, being inadequated to be used as tixotronic fluid for perfuration of oil well on the study condictions of this dissertation. The most of the results of the statistical analysis does not following the proposed mathematical models.