Abstract
Steam-Assisted Gravity Drainage (SAGD) is a complex process that often requires more control relative to conventional applications during production operations. Flow Control Devices (FCDs) have been identified as one of the technologies that offer improved downhole steam utilization and injection/production efficiency. The first FCD completions, with a helical geometry, were installed in SAGD wells at the ConocoPhillips Surmont project over a decade ago. The installations have shown improved steam chamber conformance and reduced steam-oil ratio (SOR) while accelerating bitumen production. Since then, various FCD geometries have been investigated and used, with several of them explicitly designed with a steam blocking capability. This study used a numerical simulator to investigate the performance of these various FCD geometries.
This comprehensive study started testing several geometries in a flow loop and using the data obtained to develop a mechanistic model to characterize the flow performance of the FCDs and finally evaluating their performance in a holistic manner via a numerical simulator.
By using mechanistic modeling, it was ensured that the performance of the devices was accurately represented, and the physics of the process were considered. The analysis used a commercially available numerical simulator to evaluate the performance of the various FCD geometries in SAGD operation. Three sector models representing different reservoir qualities observed in Surmont were used for the analysis. Additionally, various operating strategies were investigated for each sector model to ensure that a comprehensive understanding of each FCD geometry was achieved.
The results of this study showed that FCD flow resistance setting or nozzle size played a significant role in the production performance of the wells in liner deployed FCD applications. Additionally, the steam blocking geometries resulted in increased cumulative production and lower SOR relative to other geometries. The FCD geometry did also impact the development of the steam chamber.
Nevertheless, if the FCD completions are configured with the proper flow resistance setting or nozzle size, they provide a proactive measure, which leads to significantly better performance compared to a non-FCD completion. With lower subcool, the geometry of the FCD has a greater impact on the performance of the well. It was also confirmed that an aggressive operating strategy results in better performance of the FCD completions.
