Drilling, reservoir assesment and Monitoring

Drilling operations are performed in order to access geothermal reservoirs for energy exploitation. This chapter describes various topics, ranging from drilling of wells to reservoir preparation for exploitation. Drilling techniques are synthesised from the experience acquired on various geothermal sites in Germany, Iceland, France, Italy and the Philippines. They are specifically presented using the geological context classification introduced in the first chapter (sediments, volcanics, granites and metamorphics). Next, the hydraulic, thermal and chemical stimulations are detailed keeping the same geological context classification. Then, testing tools for characterising hydraulic connection between wells are described. The final part of the chapter establishes the state-of-