| Abstract |
Hot Sedimentary Aquifers have been exploited for geothermal energy for multiple decades (e.g., Molasse Basin – Southern Germany, Paris Basin – France). In 2006, the geothermal pioneers the Netherlands – some opportunistic greenhouse owners – saw the opportunity to drill a so-called “extended water-well” into a 2 km deep hot sedimentary aquifer in the West Netherlands Basin. Their first well design was highly influenced by the standard O&G design and global supply chain. Within the first years, detrimental side-effects were experienced first-hand: e.g., aggressive brines had a greater corrosion effect on the carbon steel tubulars, and injectivity decline. This led to necessary innovations to counteract these effects: e.g., careful material selection (more expensive but corrosion resistant alloys or GRE); or brine specific inhibitors). Currently, the third generation of geothermal wells drive the standardization in well design approach, and completion and production strategies. These experiences now guide future geothermal developments. Adaption based on learnings (i.e., data-driven decision-making), and identification and exploitation of process efficiencies: a holistic view on risk mitigation will improve the chances of future project success. |