Numerical simulation of a supercritical water/steam reservoir

Topographic map of the model area in Tuscany Copyright: © GGE Jan Niederau Topographic map of the model area in Tuscany. Black triangles indicate geothermal wells with data, the blue line the profile of the 2D numerical model ensemble assessed in this study

DESCRAMBLE (Drilling in dEep, Super-CRitical AMBients of continentaL Europe; is a European Union Horizon 2020 project funded within the “Low Carbon Energy” call: “Developing the next generation technologies of renewable electricity and heating/cooling”. New drilling technologies and concepts for geothermal energy will be financed. These concepts will increase the number of geothermal resources which are economically feasible. This includes, for example, hard rock reservoirs, as well as reservoirs with high temperature and pressure conditions. Additionally, these new drilling technologies have a smaller environmental footprint than the existing ones.

Our institute ( ) will accompany the drilling effort with reliable predictions of the physical quantities, like temperature, natural flow or rock properties, of the reservoir on regional and local scale. A thorough understanding of these quantities is needed for any commercial exploitation of such high-temperature and pressure geothermal systems. We will identify and characterize the physical conditions by numerical modelling. This will allow us to predict changes in the fluid dynamics during drilling.

  Formation of steam cap on top of the K horizon Copyright: © GGE Henrik Büsing Formation of steam cap on top of the K horizon. Shown is gas saturation of K horizon cells

A regional model will govern the natural fluid circulation in the area. Later this model will provide the boundary conditions for the local model. The two phases, liquid water and water vapor pose the main challenge for the numerical simulations. Our in-house code SHEMAT-Suite is highly parallelized and designed to handle large models and stochastic reservoir properties. We will provide a constantly updated thermo-hydraulic model of the super-critical reservoir. This model will take into account the rock properties at depth as well as the reservoir geometry and discharge of the local wells while considering the associated uncertainties.

  Huge flash of most of the reservoir from liquid to steam Copyright: © GGE Henrik Büsing Huge flash of most of the reservoir from liquid to steam. Shown are cells with gas saturation of at least 0.46

This project is funded from 01.05.2015 until 30.04.2018 by the European Union’s Horizon 2020 program under grant agreement number 640573.

Ebigbo, A., Niederau, J., Marquart, G., Dini, I., Thorwart, M., Rabbel, W., Pechnig, R., Bertani, R., and Clauser, C.: Influence of depth, temperature, and structure of a crustal heat source on the geothermal reservoirs of Tuscany: numerical modelling and sensitivity study. Geothermal Energy, 4(1), 1, (2016).

  Copyright: © GGE