ABSTRACT
Multiphase flow processes taking place in oil production operations, CO2 and/or natural gas storage in underground reservoirs, in geothermal energy production, membrane operations etc., are accompanied with undesirable scale deposits formation either on rocks or on the walls of pores or metallic equipment, rendering the corresponding operations significantly less efficient. Scale formation depends not only on the morphology and structure but also on the wetting properties of the substrates on which scale is deposited or formed through nucleation and crystal growth. In the present work, in situ nucleation and growth of calcium carbonate is investigated in a microfluidics cell both in the absence of organic phase. Nucleation and crystal growth were directly observed in both hydrophobic and hydrophilic microchannels. Results are compared with work done in batch reactors, which showed that the presence of organic, water immiscible phase accelerated the formation of calcium carbonate, while depending on the solution supersaturation different metastable calcium carbonate phases were stabilized. The confinement of the supersaturated solutions in the microchannels revealed that the mechanisms changed from bulk to surface diffusion, depending on the flow rates of the supersaturated solutions in the microchannels.
