Tratamento de água produzida de petróleo utilizando leitos coalescentes

Abstract

The production of water from the last stages of oil processing is defined as a complex effluent of variable composition: dependent on the type of field, origin and quality of the oil and the procedures used for its formation. Among the most common compounds in its composition there are: oils, complex organic compounds and dissolved mineral salts, greases, asphaltenes, chemicals added to prevent and/or treat problems inherent to the industrial process; such as biocides, anti-scaling agents, anti-foaming agents, corrosion inhibitors and dissolved gases, including CO2 and H2S. One of the main challenges in the petrochemical industry is the treatment of this produced water from wells; present in all oil and gas production operations. One of the most used parameters for the quality regulation of the produced water for well injection is the OGC (Oil and Grease Content), established by CONAMA Resolution 393/2007. Coalescing beds appear as an advantageous option for TOG reduction, as they perform the emulsion breaking process by a fiber composed of a material that provides a tortuous path for the grouping of droplets, facilitating collisions and adherence to the bed material and, subsequently, between the droplets, resulting in the coalescence process. Thus, this work aimed at the use of synthetic abrasive sponge coalescing beds for the reduction of TOG in the produced water collected from the Pilar Facility in Maceió - AL. In the first stage of tests the system was evaluated as a 5cm adsorber bed, obtaining reductions of 89% in which it was possible to observe the beginning of phase formation. Subsequently, the system was tested as an 8cm coalescing bed with reductions of 82% at the beginning of the run. In the second stage, the system was installed in a classified area, being subject to all operational changes of the process. In this stage, higher OGC reductions of 87.34% and 42.17% of TSS were obtained with clear phase formation. The results showed that even under extreme disturbance in terms of TOG concentration at the prototype entrance, the system continued reducing TOG, proving to be an alternative for the development of new industrial units providing oil recovery for the process, avoiding incrustations, operational problems, environmental impacts in the processing of oil in cases of disposal and injection of the produced water from the productor wells.