FARIAS, K. V.; http://lattes.cnpq.br/3233504439768267; FARIAS, Kássie Vieira.
Resumen:
Absence of monitoring physical and chemical properties of drilling fluids such as
viscosities, gel strength, water loss and filter-cake, may cause problems during well
perforation, e.g., differential sticking (defined as the stuck pipe). To solve this
problem it is necessary to treat the drilling fluid with dispersant and surfactant. The
aim of this work is to study the influence of dispersant additives and an anionic
surfactant over the rheological properties and filter-cake thickness of the drilling
fluids. Two samples of sodium bentonite clays called Brasgel PA and Verde-lodo,
three samples of dispersant additives, called Hexa (without surfactant), Hexa T
(with surfactant) and Spersene, and one sample of anionic surfactant were studied.
Determination of apparent and plastic viscosities and the water loss before and
after treatment with additives of the drilling fluids were performed according to the
Petrobras standard. A new methodology to measure filter-cake thickness, based
on API standard, and using an extensometer equipment were development. The
results show that values of the apparent viscosity, water loss and filter-cake
thickness were reduced when additives concentration was increased. Besides that
it is shown the importance of using dispersant and surfactant agents
simultaneously in formulating additives for drilling fluids to prevent or solve thick
filter-cake problems.