- 1Department of Resources Engineering, National Cheng Kung University, Taiwan (e44106096@gs.ncku.edu.tw)
- 2Research Center of Geothermal, CO2 Storage and Petroleum Strategy, National Cheng Kung University, Tainan, Taiwan (cocoleeeric@gmail.com)
- 3Research Center of Geothermal, CO2 Storage and Petroleum Strategy, National Cheng Kung University, Tainan, Taiwan (11207020@gs.ncku.edu.tw)
- 4National Science and Technology Center for Disaster Reduction, New Taipei, Taiwan (tony9300111@gmail.com)
- 5Research Center of Geothermal, CO2 Storage and Petroleum Strategy, National Cheng Kung University, Tainan, Taiwan (kmyang@mail.ncku.edu.tw)
- 6Department of Resources Engineering, National Cheng Kung University, Taiwan (bzhsieh@mail.ncku.edu.tw)
This study investigates optimal well configurations for sedimentary geothermal development in tilted strata, using NS mining area in western Taiwan as a case study. A numerical model was constructed using CMG STARS simulator to analyze a doublet system in the first sandstone layer, with horizontal wells designed following DEEP Corporation's "ribcage" well field concept from the Williston Basin development.
The base case model utilized one production well and one injection well, each with 1,000-meter lateral sections and 750-meter well spacing, positioned at the same depth and operating at 100 tons/hr for a 20-year period. Sensitivity analyses were performed on well positioning and production rates to determine the optimal system design. Specific constraints included maintaining bottom-hole pressure variations within 20% and achieving stable wellbore temperature for sustainable operations.
Results demonstrate that positioning injection wells at shallower depths than production wells was detrimental, leading to accelerated temperature decline and reduced facility capacity. Conversely, deeper injection well placement shows enhanced performance, particularly at higher production rates. At production rates exceeding 100 tons/hr, the configuration with deeper injection well placement achieved optimal results, reaching a 20-year average facility capacity of 1.325 MWe.
The study concludes that placing injection wells deeper than production wells in tilted strata provides superior thermal performance and facility capacity, especially at higher production rates. These findings offer practical guidelines for well design in similar geological settings, contributing to the advancement of sedimentary geothermal development strategies.
How to cite: Chang, Y.-M., Wu, C.-Y., Tang, T.-K., Hsu, W.-C., Yang, K.-M., and Hsieh, B.-Z.: Well Configuration Study for Sedimentary Geothermal Development in Tilted Strata: A Case Study in Taiwan, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5773, https://doi.org/10.5194/egusphere-egu25-5773, 2025.
