pH, sodium, potassium, calcium, magnesium and aluminum in soils contaminated with petroleum drilling fluid after leaching tests

In petroleum exploration, the use of drilling fluids is critical to the balance of pressure between the formations and the interior of the shaft, and preventing the backflow of oil from the reservoir to the oill well. Fluids are also responsible for raising the drill cuttings to the surface. However, these may potentially contaminate the environment once they arrive at the fluid-impregnated surface. This study aimed to check the pH and Na⁺, K⁺, Ca²⁺, Mg²⁺and Al³⁺ in an Oxisol and Planosol subjected to doses of drilling fluid, after suffering two leaching tests. The results showed that the addition of fluids to Planosoland Oxisol at concentrations of 4%, 8% and 16% (w / w) reduced toxic aluminum to zero and promoted an increase of the soil pH, Na⁺, K⁺ and Ca²⁺ compared to control

salinization; drill cuttings; E& P waste