Details

Autor(en) / Beteiligte

• Nitschke, Fabian
• Held, Sebastian
• Himmelsbach, Thomas
• Kohl, Thomas

Titel

THC simulation of halite scaling in deep geothermal single well production

Ist Teil von

• Geothermics, 2017-01, Vol.65, p.234-243

Ort / Verlag

Oxford: Elsevier Ltd

Erscheinungsjahr

2017

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• •Numeric model of complex counterflow related processes in geothermal single well.•Fully coupled THC model to simulate halite scaling formation in a geothermal well.•Application of Pitzer model to handle fluid salinities up to halite saturation. Using abandoned wells from oil and gas industry or dry holes, geothermal single well applications enable the prevention of drilling costs and prospecting risks which are crucial inhibitions in geothermal development. Recently, deep geothermal single wells were numerically investigated for their thermal and hydraulic performance. For the first time, we now include the chemistry of the produced brine in a fully coupled THC model for studies of scaling formation. As a case study, the 2011 circulation test of the GeneSys well Gt1 Groß-Buchholz (Hanover, Germany) was modeled successfully using the fully coupled THC code TOUGHREACT. High salinity requires application of the Pitzer ion interaction model which was verified for this particular chemical system using literature data. Modeled wellhead temperature is in very good accordance with measurements. Also simulated depth of scaling formation and total scaling volume fit to onsite observations. Evaluation of initial reservoir brine composition reveals its large impact on the range of depth where scaling occurs. Furthermore, it is shown that the presence of CaCl2 reduces halite solubility considerably and favors scaling formation. Results show that our modeling concept is capable of quantifying the complex coupled THC processes in single wells.