Abstract
Crude oil transportation through pipelines encounters severe problems due to their high pour point and viscosity. As temperature drops below the Wax Appearance Temperature (WAT) paraffins present in the crude oil start precipitating in the inner walls of the pipelines which hinder the flow to a great extent. Sometimes the pipelines even get blocked due to high wax content of the crude oils. Various pour point depressants and surfactants have been used to deal with this problem. However they are quite expensive in terms of industrial applications. To meet these problems a new surfactant extracted from tropical Indian plant Madhuca Longifolia was used to enhance flow properties of heavy crude oil through pipelines. Experimental measurements include viscosity, yield stress, viscoelastic properties, pour point, SARA analysis, microscopic studies and FTIR studies. Experimental verification of Power Law model was justified. Crude oil surfactant mixtures tend to behave like Newtonian fluid as surfactant concentration was increased from 500 to 2000 ppm. Viscosity of crude with 2000 ppm surfactant at 30°C was almost same as that of pure crude at 50°C. Presence of surfactant significantly reduced elastic and complex moduli of heavy crude oil at 40°C. Yield stress of crude oil reduced from 0.9 to 0.017 Pa with surfactant addition at 40°C. Microscopic studies showed surfactant addition reduced size of wax crystals appreciably. FTIR studies implied that aldehydic and amine groups are responsible for high viscosity and their concentration reduced after addition of surfactant.