This paper presents how to produce bitumen efficiently from the reservoir with top-water-bearing zone. The impact of naturally occurring and/or co-injected non-condensable gas on bitumen production is investigated using numerical studies. Non-condensable gas can improve energy efficiency in two ways: reduction of dynamic vacuum effect and blockage of direct contact of steam chamber and top water layer. A strategic operation mitigating the groundwater influx is presented. An artificial neural network (ANN) model adjusts both pressures of steam and non-condensable gas injected as well as the amount of non-condensable gas. The results show the optimised scheme of steam and gas push (SAGP) can improve the energy efficiency of thermal recovery by maintaining the pressure within the steam chamber enough to prevent excessive water influx, not to obstruct steam chamber expansion in early production stage.