Abstract
This study highlights the successful implementation of the cyclic steam injection process in a heavy oil field in India and in numerical reservoir simulation studies in the Orinoco Oil Belt. It focuses on optimizing key variables such as steam quality, reservoir energy transfer, well-productivity enhancement, and environmental impact. The methodology incorporates an innovative, comprehensive high-quality steam generation system, producing steam qualities ranging from 95% to 99%. In the Orinoco Oil Belt, the efficiency of injecting high-quality steam was evaluated within an extra-heavy oil formation situated at a depth of 3010 feet and under a pressure of 1100 psi. Numerical results from the Orinoco Oil Belt demonstrate a substantial impact of high-quality steam, achieving a 400% increase in oil extraction rates and an additional 28% increase in accumulated oil compared to conventional methods. This innovative system requires 8% less fuel for equivalent energy generation and leads to a 7.7% reduction in non-condensable gas production. These findings served as the foundation for designing a cyclic steam stimulation (CSS) pilot test in India. In preparation for the pilot test in India, a meticulously designed steam generation system with superheaters and cyclone separators was developed. This system demonstrates its capability by generating steam with qualities ranging from 95% to 99%, utilizing LPG as fuel. Facing challenges such as average reservoir depths of 3700 feet, low permeabilities (1000-2000 mD), oil viscosity of 20000 cP@140°F, and a pressure of 1650 psi, the execution of cyclic thermal stimulation involved 7 wells subjected to injection pressures between 1500 and 2100 psi, and temperatures of 300°C, maintaining steam flow rates from 3.0 to 4.0 tons per hour. Following thermal stimulation, oil production rates showed an overwhelmingly positive outcome with an average increase of 420%. The innovations and best practices presented in this study will facilitate the adoption of efficient thermal processes, ensuring a higher recovery factor, reduced water, and fuel consumption, and minimizing environmental impact. Operationally, non-productive periods were reduced to less than 2%, achieving steam generation with a quality exceeding 90%.
