AbstractSteam Assisted Gravity Drainage (SAGD) is a highly popular method for extracting bitumen in situ, and has gained wide acceptance for unlocking Canada's bitumen reserves. Although SAGD is very attractive, it is energy and labor intensive, produces significant quantity of emissions, and requires large water resource and treatment facility. This study addresses these issues by proposing a method to sequester steam boiler exhaust CO2, but focuses specifically on improving the energy gain ratio by reducing the energy input. The proposed method is to augment steam injection with less energy intensive, less expensive, non-condensable gases (CO2 and flue). To quantify the benefits of the method and assess the effectiveness of the process we use energy gain ratio as the main yardstick of the assessment. Five cases of SAGD were simulated with a thermal simulator using a bitumen field data. The study conclusively shows that the process is viable. Specifically the study results in four main conclusions: First, energy gain ratio can be improved by augmenting steam injection with non-condensable gases, for example, if we augment CO2 with steam in a cyclic fashion, energy gain increases by a factor of 1.5 to almost 2. Second, CO2 and flue gas produce the same energy gain ratios and the same recovery factors. Third, intermittent cyclic steam injection performs better than the continuous steam injection in terms of energy gain ratio and recovery factor. Fourth, the injection sequence and the length of the steam and non-condensable gas cycles are important to optimize water and gas breakthrough times. It can also be inferred that reducing steam injection produces economic gains by reducing water usage, fuel requirements for steam generation, and water softening volumes. Also augmenting steam with non-condensable gases reduces green house gas emissions.