Estabilização química e solidificação do resíduo oleoso gerado nas atividades de E&P de petróleo, com solo para uso em camadas de bases e/ou sub-bases de pavimentos rodoviários.

Abstract

An oily residue resulting from petroleum drilling, extraction and processing, as well as filter and reservoir cleaning and eventual oil leakage is produced. Transformation of this residue into environmentally inoffensive byproducts is the objective of every company concerned with the environment that produces this type of material. This study considered the possibility to use this residue as cementing agent to lime, using the solidification/chemical stability technique. The experimental phase of this study was based on experience and theoretical support from literature, as well as the selection of the trial methods. The trial phase was divided in four moments: characterization of the physical properties of each component of the mixture, characterization of the mechanical properties of the mixtures, characterization of the chemical characteristics of the soil, of the oily residue and of the soil-residue-lime mixture, and statistical data analyses. A pilot trial using 25% of oily residue, helped to decide the use of 3%, 4.5%, 6.0%, 7.5% and 9.0% of lime as agglomerant in the mixture. Lime increments affected mixture moisture (%), dry apparent specific mass (g/cm3), CBR (%) and expansion (%). Analysis of variance results showed a significant increase in mixture moisture, while dry apparent specific mass decreased compared to natural soil. CBRs values increased, suggesting a strong increase in resistance compared to natural soil and soil-residue mixture. Expansion values decreased significantly. In general, most of the constituents that presented concentration higher than the specified by the NBR-10004/2004 guidelines had their concentrations reduced after stabilization/chemical stabilization process. Exception was observed with manganese, although this component was not below the maximum allowed value. This fact also corroborates the advantage of the solidification/chemical stabilization process.