Gas flotation is a separation technique used in the upstream petroleum processing to reduce oil and solid particles concentration in produced water (PW). It relies on the dispersion or nucleation of gas bubbles in the water phase and their attachment to oil droplets or solid particles, which makes them rise faster. Nowadays significant attention is given to subsea produced water treatment, and gas flotation is considered a strong candidate. Moreover, due to the lower energy required to pump the produced water to the topside platform level, subsea produced water treatment can result in a substantial decrease of CO2 emissions.
At the seabed level, the process is performed at high ambient pressures and different temperatures, influencing the fluid behavior. The literature review revealed several gaps when it comes to: (i) performance of gas flotation at high pressure (ii) design of the subsea equipment for gas flotation (iii) understanding the microscopic phenomena involved in the process. 
The aim of this project is to provide new experimental methods and data that the industry can benefit from and apply to develop subsea gas flotation technology.