Significant Superiorities of Superheated Steam in Heavy Oil Thermal Recovery

With superheated steam there is no direct relationship between temperature and pressure, and it can exist at a wide range of temperatures. Superheated steam with high degree( >50 °C) of superheat has similar thermal physical characteristics with ideal gas and the heat transfer coefficient is 1/150-1/250 as much as that of saturated steam during heat transferring. It could release less energy and transmitted longer distances than that of saturated steam in heavy oil reservoirs. Numerical simulation shows that under the condition of carrying the same heat, superheated steam huff and puff enlarged the heating radius by about 10 m, oil production increment by 1463 t, oil steam ratio increase by 0.7. Superheated steam huff and puff was put into Kazakstan’s heavy oil reservoir after saturated steam huff and puff and the average daily oil production was 2-4 times that of saturated steam huff and puff, which improved heavy oil production effectively. The secondary heavy oil thermal recovery by superheated steam huff and puff applicated in marginal heavy oil reservoirs achieved satisfactory effect. Key words: Heavy oil; Superheated steam huff and puff; Heat transfer coefficient; Degree of superheat; Ideal gas