Co-Injection of Non-Condensable Gas and Foam in SAGD using a Modified Well Configuration
Date
2023-12-19
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Abstract
The purpose of this project is to evaluate the performance of a non-condensable gas (NCG) foam as an additive to the steam assisted gravity drainage (SAGD) process using the conventional as well as modified well configurations. Both laboratory experiments and numerical simulations were used in the study. For safety reasons, nitrogen gas was used in the laboratory experiments to form the foam. However, in numerical simulations, methane is used as the gas component of the foam. The purpose of foam in this process is to reduce the heat loss and to decrease the residual oil saturation. Modified well configurations are designed to enhance steam efficiencies in the target zones. SAGD experiments were conducted in linear sand-packs to evaluate the effects of NCG and Foamed NCG as steam additives on the oil recovery performance. The value of residual oil saturations under NCG or foamed NCG conditions were determined through history matching of these experiments with numerical simulation. Several different foaming agents were evaluated for their effectiveness in reducing the residual oil saturation and achieving high recovery factor. The best performing foaming agent NC160 was then evaluated in a linear physical model for its foam flow characteristics. The results of these tests were also history-matched with a thermal reservoir simulator to determine the foam flow characteristics that can be applied to field scale simulations. A numerical simulation study of Long Lake Pad 16 found that steam only SAGD operation in 10 years had a cumulative Steam Oil Ratio (cSOR) of 6.23 and the total oil production of 79,193 m3. However, the best performing case of foam assisted SAGD, using three horizontal wells configuration, reduced the cSOR to 3.94 and increased the total oil production to 85,068 m3. As expected, a foam insulation layer formed above steam chamber, which resulted in superior performance regarding steam efficiency. This field scale simulation study was based on the foam flow parameters determined through history matching of the lab-scale physical model tests.
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Keywords
Surfactant, Non-Condensable Gas, Thermal Recovery Process, Foam, Modified Well Configurations, SAGD
Citation
Zhang, Y. (2023). Co-injection of non-condensable gas and foam in SAGD using a modified well configuration (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.