This paper will present a workflow describing the integration of hydrogeological and coal-seam gas (CSG) simulation models into one regional 3D numerical flow model covering an area of 197,000km2 of the Surat B asin, Queensland, Australia. The model is designed to allow QGC to further understand and quantify the potential impacts of CSG production from the QCLNG project on the regional groundwater system and to synthesise geological, hydrogeological and engineering data into a one-Earth model.
The model combines knowledge and concepts from previous work including regional-scale single-phase hydrogeological models using MODFLOW, and more local-scale modeling of the Walloon Subgroup using ECLIPSE* 100. It incorporates a hydrogeological conceptualization, a structural and stratigraphic interpretation; property modeling (taking into account public and QGC well data); an ECLIPSE* model and several calibration steps together with the dual-porosity/dual-phase flow behavior inherent to CSG simulation. This paper will demonstrate that via one model, it is possible to simulate the potential effects of CSG production on the groundwater environment, including both the localised dual-phase effects of CSG production and more regional-scale single-phase groundwater movement.