WP6 - Macro-Scale Investigation

Objectives: Based on the knowledge gained from the experiments at the micro (WP4) and meso-scale investigations (WP5), the aim of the planned field application is to confirm the conclusions drawn from these tests as well as results from the integration work package (WP7) and to verify the possibility to improve the wellbore performance of a geothermal well at in-situ conditions. Therefore, two field experiments will be performed in two representative geothermal reservoir types. For the different sites, analogue rock samples will be tested in WP4 and WP5. Based on the results of these tests, the most promising candidate for a successful productivity enhancement operation will be selected in the sedimentary (The Netherlands) as well as in the magmatic (Iceland) environment. In the course of the project preparation several well owners expressed interest in the application of a radial jet drilling operation in relation to this project (see Letters of Intent at the end of the proposal). A pre-selection has been performed and contingency sites are available in Iceland, The Netherlands as well as in Groß Schönebeck (GFZ owned site). For drilling depth and direction selection, a novel strategy using state-of-the-art technology will be applied. Flow testing and logging before and after the radial jet drilling operation will be used to quantify the benefit as well as the long term performance of the enhancement technology. The work can therefore be outlined as follows:

  • Develop strategy for use of drill cuttings, televiewer and other logging or surface instruments for setting the depth and direction for radial penetration.
  • To apply on-site radial drilling in at least two wells.
  • To use flow or injection testing of the wells before and after radial drilling and if drilled in several depths, the effect of each drilling depth.