The Dover Project (formerly the Underground Test Facility) is the world's first field pilot of the Steam Assisted Gravity Drainage (SAGD) process using dual horizontal well pairs to, recover bitumen. There have been four phases of SAGD piloting at the Dover site thus far. The Phase B pilot, which consists of, three 500 in long horizontal well pairs spaced 70 in laterally apart, has been in continuous operation since early 1993. Phase B reached the peak production rate of 300 m(3)/d or 100 m(3)/d per well pair on average in the middle of 1994. After sustaining the peak rate for about two years, the production has been in decline. with a steady increase in steam-oil ratio. Research carried out in; the past few years suggested that the addition of a suitable amount of non-condensable gases (NCG) would be an effective method to wind-down the steam chamber. It provides an economic means to continue bitumen production by utilizing the: large amount of heat stored in the SAGD chamber. Beginning in April 1998, a small amount of natural gas was added continuously to the steam injection. The concentration of NCG has increased steadily in the past 3.5 years. The resulting performance has been better than initially expected. Based on the success of this NCG-steam wind-down strategy, a four-month flue gas injection test was conducted in 2001 to investigate the possibility of using the more cost-effective flue gas, rather than natural gas as an injectant. This paper summarizes the rationale for selecting the NCG-steam wind-down strategy, the field implementation of the flue gas injection test, and the resulting pilot performance. The successful implementation of this technology will have a profound impact on the overall process economics.