HydroFlame Technologies, LLC (HFT) is proposing to study the feasibility of combusting liquid fuels in the air core of rotating water for application in a downhole steam generator (DHSG). Deep reserves ( & gt;2500 ft) can be accessed by application of DHSGs. DHSGs increase the efficiency of steam generation and injection by eliminating heat losses via pipeline, wellbore and vent gases. The operating lifetime of a DHSG is severely shortened by combustor/burner failures resulting from thermal stresses when the combustor walls are cooled by the feed water running in a sleeve placed around the combustion area, as was proven by US-DOEs project Deep Steam in the 80s. HFTs proposed solution is to have the feed water inside the combustion area in direct contact with the flame. This is achieved by creating rotating films of the feed water so as to cover the combustor inner walls and igniting flame within the air core of the rotating water. The combustor walls see only the water temperature, thus, eliminating thermal stresses and combustor failure. Phase I will address generation of self-sustaining flame within the air core of rotating water films and combustion efficiency. Liquid fuel atomization will be studied and a design that generates desired spray pattern will be selected. Combustion experiments will be conducted at pressures less than 120 psig using diesel fuel. Mixing of atomized fuel and air takes place in the air core giving rise to diffusion flame. Combustion efficiency will be studied to achieve soot free combustion within the air core. Successful Phase I will be carried over to Phase II to design and build a 5 MMBtu/hr liquid fuel burning DHSG. With declining light oil discoveries, the vast reserves of heavy oil are becoming increasingly important as a future energy source. Advancement of liquid fuel combustion, such as diesel, propane and even the produced oil itself, brings about enormous savings for heavy oil producers. Carbon dioxide produced during combustion is injected with steam into oil formations reducing greenhouse gas emissions. A DHSG capable of burning liquid fuels presents an economic solution at locations where natural gas is not readily available.