Abstract: Superheated steam, compared with wet average steam, has higher heat content and specific volume, by which for steam stimulation, not only can the bottom hole steam quality and steam swept volume be increased, but also it is characterized by higher visbreaking, heat expansion, blocking, crude distillation rate and oil displacement efficiency than those by wet average steam. The upsalt heavy oil reservoir in Kenjiyake field has experienced pilot test of superheated steam stimulation using direct steam generator integrated with steam-reheated devices, and good responses are gained. Compared with wet average steam stimulation, the superheated steam stimulation applied to such a heavy oil reservoir development is of more perfect effect.

Key words: superheated steam, heat content, specific volume,steam quality, upsalt reservoir, efficiency