Strategies for heavy oil production with thermal recovery in heterogeneous reservoir

Abstract

Heavy-oil is one of the main energy sources in the future. However, with the high viscosity of heavy oil, steam-flooding is one of the major techniques to produce this oil. To determine a favorable operating condition, many recent studies have evaluated different methods. However, there is no single optimum value for all reservoirs or all modes of operation. In this study, it’s aimed to investigate the strategies of selecting well spacing, injection rate, and different development periods in various areas, based on the real field data. The practical field data has been applied to simulate the inverted 5-spot steam-flooding process by using STARS, a CMG program. The project life is simulated in 20 years of production. Judging criteria of parameters are dependent on the weighted factors (1.37: 1) of maximum recovery factor/area/well and minimum cumulative steam-oil ratio/area/well. The simulation results show that the injector - producer distance at 282.8 m with 120 m3/d injection rate yields the most favorable conditions for the selection of well spacing and injection rates. Therefore, the field is evaluated by operating different areas in 10 years time basis. It's indicated that the injector - producer distance at 141.4 m with 120 m3/d injection rate is preferred for the first 10 years' operation in zone 1 area only. In terms of 20 years, the injector - producer distance at 141.4 m with 30 m3/d injection rate is more favorable.