Heterogeneity Impact on SAGD Process Performance in Mobile Heavy Oil Reservoirs

Abstract

The increasing oil demand and the significant amount of heavy oil/bitumen reserves will motivate a huge effort on the development of heavy oil reservoirs in the next decades. Within this framework, Steam Assisted Gravity Drainage (SAGD) is a very promising technique to produce heavy oil from thick and high permeability reservoirs. The small scale field tests conducted up to now highlighted the influence of heterogeneities on the development of the steam chamber involved in SAGD. This work presents a numerical investigation of the effects of heterogeneity on SAGD performance when applied to produce mobile heavy oil. A set of reservoir models is randomly generated with 0, 10, 15 and 20% of shale and a statistical analysis is performed to quantify the impact of shale distribution on oil production and SAGD efficiency. It is shown that the influence of shale baffles depends on their locations relatively to well pairs, the most detrimental ones being located between the injector and producer. In addition, we observe that 1/2, 1/3 and 1/4 only of the cumulative oil volume produced for the homogeneous model after 3 years of SAGD process are recovered when shale proportions are 10, 15 and 20% and that CSOR evolves from 2 for the homogeneous model to 3 for the models with 20% of shale.