Innovation progress and thinking of SAGD technology in heavy oil and oil sand

Steam assisted gravity drainage technology (SAGD) is now one of the most commonly used thermal recovery technologies in heavy oil and oil sand mining. Compared with traditional technologies like steam injection or in-situ combustion, it has such advantages like stable displacement, large stratum contact area, good oil displacement effect and high recovery rate, but there also exist some problems like high cost, short cycle of steam, etc. In order to better guide technical innovation in heavy oil and oil sand recovery, research has been conducted on new progress based on SAGD. This paper elaborates the principles, innovations and advantages and disadvantages of five new technologies based on technical innovations in SAGD, i.e. single well SAGD (SW-SAGD), expanding solvent SAGD (ES-SAGD), foam solvent SAGD (FA-SAGD), combustion-assisted gravity drainage (CAGD) and steam assisted gravity drainage with oxygen (SAGDOX). It concludes that innovation lies in that combination of well-type change and steam solvent enlarges the steam chamber and hence improves the energy utilization and recovery rate and in that the combination of steam injection and combustion method maximizes the exploitation of effective energy. Innovations based on SAGD provide technical references for follow-up technical reserves and innovations for the development of heavy oil and oil sand.