Solvent vapour extraction (VAPEX) has shown great potential to recover heavy oil reserves. However, the application of the VAPEX technique is limited by its low oil production rate, which is caused by the slow mass transfer and inefficient gravity drainage. Hence, increasing the heavy oil–solvent mixing process and introducing more production mechanisms are imperative to enhance the performance of VAPEX. This paper proposes a new process, namely enhanced VAPEX, in which the solvent-chamber pressure is dynamically operated rather than constantly maintained throughout the production process. During the enhanced VAPEX process, pressure in the solvent chamber is cyclically depleted to induced foamy oil flow, which not only adds oil production but also increases contact area. In addition, a high-pressure non-condensable gas is applied to induce fingering phenomenon, which enlarges the heavy oil–solvent contact area. The enhanced VAPEX process is experimentally evaluated in this study. It is found that gas fingers can penetrate deep into the oil zone. In addition, foamy oil flow not only increases oil production but also improves mass transfer. Experimental results show that the oil production rate of the conventional VAPEX process was increased by 182% by the enhanced VAPEX process.

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