Otimização do processo de organofilização de bentonitas visando seu uso em fluidos de perfuração não aquosos.

Abstract

The water base fluids are widely used in the drilling of wells, however, some drilling operations are sensitive to contact of water like shales and ultra deep and no aqueous fluids are used for drilling. In these cases, the bentonite clay, used as a viscosifier agent can not be used without treatment for their organic surfaces become hydrophobic and it can be dispersed in organic ways. These clays after treatment are called organophilic clays, and are usually obtained by adding, in water, a quaternary ammonium salt where its cation replaces on the clay mineral structure the present cation that is generally sodium. The process of organofilization, composed of several steps, do not produce organophilic clay of high quality, and highlight the importance of process variables and the choice of raw materials to be used. This work propose, a detailed study of the variables involved in the process of dispersion of bentonite clay (speed of agitation, time and temperature of curing), and also in the process of organofilization (time and temperature of curing) trying correlate apparent and plastic viscosities of dispersions clay with the efficiency of the organofilization, and observe the influence of other variables involved directly in the organofilization (type of clay, type of surfactant and the presence of sodium deflocculant). The process of organofilization will be optimized observing the results of X-ray diffraction, thermogravimetry, Foster swelling and apparent viscosity of fluids. This work shows that the variables involved in the process of dispersion of clay and in organofilization, by characterization, have no influence on intensity and in the position of displacement of the peaks of basal interplanar distance caused by addition of surfactant to bentonite clay been influent the type of clay and surfactant and the presence of sodium as a deflocculant, and have influence in rheological properties been influent too the type of clay and surfactant.