Na exploração do petróleo, o uso de fluidos de perfuração é essencial para o equilíbrio da pressão entre as formações e o interior do poço, além de impedir o refluxo do reservatório de petróleo ao poço. Os fluidos também são responsáveis pela elevação dos cascalhos de perfuração à superfície. Entretanto, estes podem ser potenciais contaminantes do ambiente, uma vez que chegam à superfície impregnados de fluidos. O trabalho objetivou avaliar o pH e os teores de Na+, K+, Ca2+, Mg2+e Al3+em um Latossolo e um Planossolo submetidos a doses de fluido de perfuração, após sofrerem dois ensaios de lixiviação. Os resultados mostraram que a adição dos fluidos ao Planossolo e Latossolo nas concentrações de 4%, 8% e 16% (m/m) reduziu o alumínio tóxico a zero e promoveu aumento do pH do solo, Na+, K+e Ca2+em comparação ao controle

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

In order to evaluate possible solubility of BaSO4 in soils under reducing conditions, column leaching assay was settled down, where the soil received three doses of BaSO4 (100, 300 and 3000 mg kg-1) at two humidities. After reaching an Eh of -200 mV rainfall of 200 mm per day-1 was simulated. The condition of reduction led to the increased levels of barium in the fractions of higher lability and the highest levels of barium in the leachate extract, which were above the potability standards. Only 0.05% of barium in the column that received the highest dose was removed by leaching.