Steam-assisted gravity drainage is one of the most efficient thermal methods to develop heavy oil and bitumen accumulations. However, SAGD requires a large amount of steam injection especially in long production time, which may make the process uneconomical. As an improvement of SAGD technology, steam and gas push (SAGP) has attracted more attention due to its better performance. This method involves the addition of a non-condensable gas such as carbon dioxide co-injected with steam, which reduces the total amount of steam needed and improves energy efficiency. Due to the geological tectonic movement, heavy oil reservoirs with dip angles are widely distributed around the world. The influence of reservoir dip angle on SAGP method must be seriously considered. In this paper, the development effects of SAGP and SAGD methods for heavy oil reservoir with dip angle are compared based on the basic production parameter SOR and cumulative oil production by CMG-STARS. Secondly, the steam chamber evolution of dip angle reservoir with time is analyzed. Finally, we improve the low production caused by reservoir dip angle by optimizing well pair location. The well pair should be placed close to the side boundary in downdip zone, not in the center of the reservoir by numerical simulation. The results show that SAGP process is more suitable for dip Angle reservoir development than SAGD process. In addition, carbon dioxide injection in SAGP process is also conducive to reducing greenhouse effect and contributing to environmental protection This paper has a certain guiding significance for the development of widely distributed dip angle heavy oil reservoir.
Keywords heavy oil recovery, dip angle, thermal recovery, SAGP method, SOR