Incorporation of Açaí Pit Ash as an Eco-Friendly Chemical Additive for Water-Based Drilling Fluids in Oil Well Operations.
Açaí seed ash; Chemical characterization; Eco-friendly drilling fluids; Drilling fluid properties
The growing demand for sustainable practices has encouraged the reuse of agro-industrial residues in high value-added applications. In this context, the oil industry has sought ecological alternatives to the additives used in drilling fluids in order to reduce environmental impacts. At the same time, the açaí production chain (Euterpe oleracea Martius), widely exploited in the Amazon region, generates large volumes of solid waste—the seed—which represents about 80% of the fruit. Part of this material is burned for energy generation, resulting in a secondary by-product: açaí seed ash. Therefore, this study proposes the use of this ash as an alternative additive in water-based drilling fluids, with an environmental focus (eco-friendly drilling fluids). As the main methodological steps, açaí samples were collected in the city of Óbidos-PA, sieved, and separated into granulometric fractions of 707–300 μm, 297–149 μm, and 707–149 μm, which were applied to the drilling fluid to replace the calcium carbonate used in the reference formulation. The açaí seed ash was characterized using different instrumental techniques, including ash content analysis, thermogravimetric analysis (TGA), X-ray fluorescence spectroscopy (XRF), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) for morphological evaluation. The formulated fluids were subjected to a series of performance tests, including sag resistance, rheological behavior, filtrate volume measurement, and filter cake characterization. These tests made it possible to evaluate the performance of the ash in the drilling fluid, and the results demonstrated that the ash presented performance comparable to or superior to that of calcium carbonate, promoting improvements in parameters such as plastic viscosity, yield point, and filtrate volume. Thus, this research highlights the potential of açaí seed ash as a sustainable input for the oil industry, contributing both to the valorization of regional waste and to the advancement of cleaner technologies in drilling operations.