Numerical simulation on kilometer-scale fault-related thermal anomalies in tight gas sandstones

Numerical simulation of convection cells in a vertical fault.

Supervisors: Prof. Dr. Thomas Kohl, Dr. Maziar Gholami Korzani

Person in charge: Guoqiang Yan

Large-scale natural convections systems in a faulted sandstone reservoir are investigated using the finite element code TIGER. The selected illustrative research location (Piesberg quarry, Lower Saxony Basin, North Germany) has a thermal anomaly in the reservoir outcrop analog of circa 300°C. The origin and development of this anomaly are investigated within this study, targeting the analysis of natural convection systems. This study demonstrates that the local thermal anomalies are presumably provoked by circulating hydrothermal fluids along the fault damage zone of a large NNW-SSE striking fault, laterally heating up the entire exposed sandstone reservoir. Results suggest that this thermal event was reached prior to peak subsidence during Late Jurassic rifting (162 Ma). Owing to the idealized nature of the presented models, the numerical results and the associated analytical solution can be applied to petroleum and geothermal system models to avoid overestimating of burial depth and reservoir quality, etc.