|
|
| |
Can Next-Generation Enhanced Geothermal Systems Succeed in Deep Sedimentary Basins?
Shuvajit BHATTACHARYA, Kartik MAWA, Mojdeh DELSHAD, Peter EICHHUBL, Kenneth WISIAN
[The University of Texas at Austin, USA]
Deep sedimentary basins contain significant geothermal resources for power generation, and these regions often benefit from existing oil and gas infrastructure, subsurface data, an experienced workforce, permitting regulations, and growing power demand. Despite these advantages, field demonstrations and commercial development of the latest styles of Enhanced Geothermal Systems (EGS) have predominantly focused on crystalline basement reservoirs in the western US. In deep sedimentary basins, such as the US Gulf Coast, potential EGS target temperatures (for power generation) are typically located at depths of 4 to 6 kilometers due to modest temperature gradients. Compared to EGS in high-heat flow areas in the western US, these greater target depths result in higher drilling and completions costs, making geothermal power generation less competitive compared to existing natural gas and renewable energy markets. Yet, with novel cost-efficient development and production strategies, geothermal could be attractive for baseload power generation. This study discusses similarities and differences between crystalline basement and deep sedimentary rocks, such as tight sand and shale. What can be done to make EGS at scale in deep sedimentary basins more viable? The study reviews some of the practices of EGS and oil/gas industries and explores whether those are necessary and practically applicable to EGS development in deep sedimentary rocks or if innovative methods or hybrid approaches (e.g., new well configurations, stimulation operations, reactive fracture growth, fluid design, etc.) could enable cost-effective and sustained heat production. The study shows preliminary modeling results from deep sedimentary reservoirs in the US Gulf Coast, which could be good candidates for EGS field pilot tests. The findings, conceptual framework, and proposed recommendations in this study provide a road map for future research and practical implementation of EGS in deep sedimentary basins.
Topic: Enhanced Geothermal Systems