A preliminary assessment of thermochemical fluid for heavy oil recovery

Commercial production of heavy oil has heavily relied upon steam injection method due to its effectiveness to reduce the viscosity and improved mobility. However, due to uncertainty of oil price, high energy cost, water requirement, heat loss, and environmental issues, attention is being given to new thermal EOR technologies such as insitu steam generation using thermochemical fluid (TCF) injection. This technology essentially involves downhole generation of heat and pressure from exothermic chemical reaction. In this investigation, thermochemical reactants were injected, at different temperatures (100, 50, and 30 °C) and constant rate of 0.5 ml/mln, into Berea sandstone core samples saturated with heavy oil (18 %wt./wt. asphaltene content and 11° API) and brine. It was observed that the pressure generated at the inlet of the core due to 100, 50, and 30 °C injection temperatures of the thermochemical fluids rose to 1600, 1200, and 280 psi, respectively; while the recovery factor was 83%, 66% and 54% OOIP, respectively. In comparison, from the injection of steam generated at 250 °C, the pressure at the inlet of the core was 212 psi and the recovery factor was 71% OOIP. These results therefore confirm increase in interest in the application of the TCF injection technology in heavy oil production.