Industrial & Engineering Chemistry Research, Vol.58, No.36, 16552-16564, 2019
Amphiphilic-Polymer-Assisted Hot Water Flooding toward Viscous Oil Mobilization
Heavy oil recovery is the most challenging part for the petroleum industry, and several techniques including steam and water injection are currently used that are either energy intensive, expensive, or less efficient. This study aims to evaluate a novel amphiphilic viscosity reducing polymer (DN-1) used along with hot water flooding for promoting viscous oil mobilization. Its performance for heavy oil mobilization was evaluated using viscosity measurements at different temperatures followed by core flooding experiments. Our results indicate that DN-1 at low concentrations could form 3D networks and stable aggregates. DN-1 featured good interfacial properties including low CMC, low IFT, and small contact angle. Even at low concentration it could form dynamic oil in water emulsions, thereby causing easy emulsification and fast demulsification. The injection pressure of DN-1 was much smaller than that of the conventional polymers or associative polymers used for heavy oil development and is beneficial for oil recovery in real reservoir scenarios where a high-pressure gradient cannot be achieved. Interestingly, unlike polymer flooding, this amphiphilic polymer increased displacing phase viscosity, while it simultaneously reduced the displaced oil viscosity. Finally, DN-1-assisted hot water flooding could impressively achieve an ultimate recovery factor of 75.7% at 115 degrees C that was similar to that by hot water flooding at 175 degrees C. Even when DN-1 was injected at 55 degrees C, which was the reservoir temperature, the oil recovery factor was still 12.8% higher than hot water flooding, proving it as an efficient material in improving heavy oil recovery at low temperatures. As per our knowledge, this is the first report on the use of amphiphilic-polymer-assisted hot water flooding for heavy oil recovery.