Estudo do tratamento de resíduos de fluidos de perfuração de petróleos de base aquosa

Abstract

Drilling fluids commonly used in the petroleum exploration and production stage are of the aqueous base type. This type of fluid has less environmental impact when compared to oil base fluids. During and after the process of drilling and prospecting the oils, the residue generated, in the form of mud, contains several potentially polluting compounds, especially hydrocarbons. This waste is disposed of in industrial landfills for treatment, thus raising industrial operational costs. In this work, a process of separation of the residual oil from water-based drilling fluid waste was developed by a combination of physicochemical methods. Relevant parameters were temperature, centrifugal force and the use of synthetic and natural polymers. Results showed that an increase in centrifugal force and temperature is essential for separation of the oil phase. The use of polymers improved efficiency by completely removing the oil from the residue, around 20% v/v. The characterization of the recovered oil classified it as light oil with density at 20 °C of 0.7997 and API gravity of 44.4, a low sulfur content (0.0667 wt %), total acid number 0.812 mg of KOH.g-1 , water content 0.58% v/v and saturated, aromatic and polar contents of 64.11, 5.19 and 30.70 wt %, respectively. These results show that is possible to recover a viable oil that can be incorporated at the midstream stage, thus avoiding disposal, reducing the residue amount, operational costs and environmental impact.