Characterization of drilling cuttings generated in oil and gas pre-salt drilling activities and leaching studies of contaminants present in these samples employing saline and aqueous solutions

Abstract

This article describes the characterization of pre-salt drilling cuttings generated during offshore activities. Samples were submitted to leaching by employing saline and aqueous solutions to evaluate the leaching of contaminants in marine and aqueous environments. The results of tests on samples indicated that some of the heavy metals had high levels of contamination. The metals present in the highest concentrations in saline and aqueous leachates were Si and Ba. Probably, the presence of Ba in the leachates was associated with leaching of barite. The metals Cd, Cu, Ni and Zn were present in varied concentrations in the saline leachates, and the metals Si, Ba, Cu and Zn were found in the aqueous leachates. There was a tendency of higher concentration of TOC in saline leachates derived from samples containing aqueous-based fluids, which may be related to the greater leaching tendency of polymers and emulsifiers in this medium.