Análise quanti-qualitativa no contexto dos aspectos regulatórios do descarte no mar de fluidos aquosos e cascalho da fase reservatório de poços

Abstract

To regulate offshore discharge of drilling fluids and cuttings from, the Brazilian environmental agency promulgated the Normative Instruction 01/2018, which was suspended the following year. This regulation would prohibit the marine discharge of waste from the reservoir section, regardless of oil contamination. Its adoption was justified as a precautionary measure, given the lack of quantitative information on hydrocarbons in these wastes. This dissertation aims to analyze the international panorama on the subject, evaluate and compare concentrations of total petroleum hydrocarbons and polycyclic aromatic hydrocarbons in samples of these wastes, and propose improvements to the current guidelines in Brazil. This is a quantitativequalitative study. The sampling plan included the collection of aqueous fluid and cuttings samples before and during the drilling of the hydrocarbon-bearing zone in 20 offshore wells. Subsequently, total and polycyclic aromatic hydrocarbons were quantified. Descriptive statistics were employed to characterize the generated results. The Mann-Whitney test was used to compare central tendency values between the groups before and during drilling. The results indicate concentrations of total petroleum hydrocarbons, especially in aqueous fluid samples, below 1% w/w. Most results for polycyclic aromatic hydrocarbons were below the method's quantification limit. A significant difference was found between the groups before and during drilling, especially for polycyclic aromatic hydrocarbons. The qualitative investigation revealed the absence of prohibitive measures in international regulations. This study concluded that there is no technical justification for implementing an indiscriminate prohibition on the disposal of reservoir phase waste. A series of measures were proposed to improve the current regulation, such as the continuation of studies, incorporating it, in an adapted form, into the monitoring routinely carried out by operators.