Hydrogeologic, Geologic, and Sustainable Challenges and Interpretations for the Installation of a Geothermal Well

To effectively design a geothermal standing column well (SCW) field and energy system it is important to first install and test a pilot well. The data collected from the pilot well support the design of the SCW field in several ways. Pre-drilling exploration can reveal bedrock types, structure, and characteristics, aquifer yield, and groundwater quality/characteristics of the environment into which the geothermal is intended to be installed. This determines whether the site is suitable from a cost-effective perspective. For example, certain rock types are more effective at providing thermal transfer; while estimated groundwater yield and hydraulic conductivity determine viability of bleed and alternate groundwater uses. Geochemical characteristics are used in the evaluation of encrustation, scaling or bio-fouling of heat ground source heat pump equipment. The pilot test also provides information for full scale-up SCW design including optimal SCW depth, and the number of wells required. Therefore, research, pilot testing, and collection of scientific data prior to completing a SCW design is critical to avoiding costly mistakes.