Composições de argilas bentoníticas para utilização em fluidos de perfuração de poços de petróleo.

Abstract

This work has a objective to study bentonite clays compositions that make possible the uses of low quality clays available in deposits of Boa Vista, PB, for use in drilling fluids of oil well. For this purpose, three samples of natural bentonite clays (Bofe, Chocolate and Verde-lodo clays) and one industry sample (Brasgel PA clay), used as reference, were selected of Boa Vista, PB. Through of the mixture design, methodology of response surfaces and optimization graphic was studied the apparent (VA) and plastic (VP) viscosities and water loss (VF) of dispersions prepared with clays compositions. The results allowed to delimit a range of Bofe, Chocolate and Verde-lodo clays compositions, that viability of blendings with properties according to actually standards for drilling fluids oil well applications and make possible the use of low quality clays (Verde-lodo and Bofe clays). Was evaluated influence of the different addition of sodium carbonate and mixtures processes in properties VA, VP and VF of dispersions prepared with clays compositions and depending of the clays composition, improvement or no the properties. The mixture process of clays is accomplished after transformation of the individual clays in sodic, in all amounts of sodium carbonate used, make possible the use of Bofe and Verde-lodo clays and minimizes the use of Chocolate clay, the best quality. The polymers additives study the protection and recovery of VA, VP and VF of dispersions prepared with compositions VB (66,7% of Verde-lodo + 33,3% of Bofe) and BCV (66,7% of Bofe + 16,7% of Chocolate + 16,7% of Verde-lodo). The results making possible the fluid resistant to action of degradation agents. The study of compositions clays will get innumerable useful benefits to Boa Vista mining, the industry and the petroleum sector, possibility the use of low quality clays, available in bigger amounts in deposits, for use in drilling fluids of oil well.