High-pressure direct-fired steam-gas generator (HDSG) is to produce multiplex thermal fluid (contains water, CO2, N2 etc.) through efficient direct-contact heat transfer, which would utilize the flue gas heat and reduce the gas emission caused by ordinary boiler. Furthermore, the multiplex thermal fluid can promote the heavy oil recovery by both steam flooding and miscible flooding. This paper introduced three kinds of HDSG: pressurized submerged combustion vaporization (PSCV), multiplex thermal fluid generator and supercritical hydrothermal combustor, which are different in work pressure and method of mixing water and flue gas. Then, we discussed the economic efficiency of HDSG used for heavy oil recovery and concluded that although the pressurization of fuel and oxygen would cost as much as the energy saved by utilizing the flue gas heat, using HDSG for heavy oil recovery has other incalculable benefits such as miscible flooding, waste water treatment and reduction of heat loss through injection well. Finally, we indicated that supercritical hydrothermal combustor will be the trendy of HDSG and pointed out the future research should be carried out on the heat and mass transfer characteristic of the combustion field when water presents and the combustion stability and completeness when pressure increases.
Simulation of Steam-flooding Thermal Heavy Oil Recovery Process with Sequential Implicit Method
