Generation and characterization of oil-in-water (O/W) emulsions under conditions of reduced oil concentrations

• Grant number: 23/07040-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2023
• End date: June 30, 2024
• Field of knowledge: Engineering - Mechanical Engineering - Transport Phenomena
• Principal Investigator: Alex Roger Almeida Colmanetti
• Grantee: Davi Pereira Carvalhal
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Despite the global trend of moving to a low-carbon economy, seeking to decrease the consumption of fossil fuels to minimize greenhouse gas (GHG) emissions, it is expected the maintenance of the the large-scale use of energy resources from fossil fuels in the coming decades. In Brazil, oil and gas production was mainly driven by discoveries of new oil reserves in the pre-salt layer, located offshore. A great challenge for the oil industry in this environment is the treatment of produced water (oil-in-water emulsion), which is a effluent found in large quantities during oil production at oil platforms. This effluent is usually used for reinjection in mature wells (to increase their productivity) or it is disposal in oceanic waters. However, in both conditions, the produced water (oily water) should attend the criteria established by the Brazilian National Council for the Environment (CONAMA). CONAMA Resolution 393/2007 regulates the disposal of this effluent in offshore platforms. According to this resolution, oil platforms can discharge water produced with an average oil and grease content (TOG) of a maximum of 29 mg/l. Acceptable levels of oil and grease content (TOG) for the disposal or reinjection of produced water are achieved in oil platforms through phase separation processes such as (i) gravitational separators, (ii) hydro-cyclones, and (iii) floaters. In this context, this project deals with an investigation that deals with the generation and characterization of oil-inwater emulsions (O/W) with reduced oil concentrations (oil and grease content (TOG)), equivalent to produced water discarded in oil platforms. Characteristics of emulsions (O/W), such as distribution and droplet size (DTG), emulsion stability (O/W), and oil and grease content (TOG) will be experimentally evaluated in a setup composed of a horizontal pipe with an internal diameter of 14.8 mm and 9.25 m in length (D = 14.8 mm and L = 9.25 m). The setup is in full capability at the Laboratory of Thermal and Fluid Engineering (LETeF) at the São Carlos School of Engineering (EESC-USP). The reproduction of an emulsion (O/W) with known characteristics of distribution and droplet size (DTG), oil and grease content (TOG), and stability is fundamental for carrying out studies involving emulsion separation processes (O/W), whose demand is growing in the current scenario. Emulsion generation (O/W) will be performed through a generator device specially developed for this purpose. The emulsion (O/W) samples will be collected throughout the test section. The measurements of the oil and grease content (TOG) will be carried out using the spectrometry technique. The droplet size distribution (DTG) will be evaluated through an online particle analyzer that operates based on the principle of laser diffraction and the emulsion stability (O/W) assessment will be performed using the "bottle test". In addition, the purpose of this project is to perform the validation of DTG measurements obtained by the particle analyzer, through the capture and processing of emulsion flow (O/A) images obtained through a high-speed video camera (Phantom® v2012).