Drilling of a geothermal exploration well in Yuanshan in Yilan County, Taiwan to a depth of 4000 meters has been completed. Although the temperature at depth was below expectations, the well still provided valuable information into the subsurface and the characteristics of the geothermal resource at the study site.
As reported on October 2024, drilling in Yuanshan was done by CPC Taiwan and Academia Sinica. Exploration methods including magnetotellurics, reflection seismic surveys, and seismic wave imaging were employed to identify the drilling site. Drilling was completed by August 2025.
Preliminary data from the well indicates that the formation temperature at a depth of 4000 meters was only 150 °C. According to CPC Taiwan, the ideal depth to access 150 °C should only be at about 3000 meters for the development to be profitable. The company further stated that deepening the well would be too costly and risky. The project partners are currently doing more exploration work in Yuanshan, primarily to evaluate if the high-temperature strata can be found in shallower areas.
Although the first well did not produce the ideal results, CPC Taiwan states it has helped them to gain relevant experience in deep geothermal exploration. CPC has already started drilling operations on another deep geothermal well in Dongshan, also in Yilan County. The target depth for this well will be at least 3000 meters.
Source: Liberty Times Net
