Santos Analytical Regional groundwater Model not calibrated Limited deterministic Santos Gladstone model model uncertainty analysis: (2009a), Dual-phase flow, coal dual porosity and anisotropy, and LNG Project, (Roma Sensitivity analysis (four Santos Model domain limited to geomechanical effects not included Australia field), cases) for specific (2009b) project area Coal seams not modelled independently of coal MODFLOW aquifer parameters and Time-varying constant measures (Comet recharge for the head boundary condition Ridge field) MODFLOW model, and Vertical movement of groundwater not well constrained used to represent well for storativity for the Aquifer confinement and interconnection simplified (rather than pumping/flow analytical model rates) for MODFLOW Effects of geological faults assumed insignificant CSG well fields were model; constant pumping Analytical modelling did not account for size of well modelled separately and rate used to represent cumulative impacts Apparently no accounting of groundwater–surface water well field in analytical associated with other interaction model developments assessed on a qualitative basis Basin MODFLOW Regional groundwater Dual-phase flow, coal dual porosity and anisotropy, and None QGC (2009) model CSG region geomechanical effects not included – divided into three Coal not modelled independently of coal measures subdomains (hydraulic No consideration of rainfall recharge compartmentalisation assumed) Simplified geology, homogeneous isotropic conditions Time-varying constant Cumulative impacts not assessed head boundary condition
Santos Gladstone LNG Project, Australia Analytical model (Roma field), MODFLOW (Comet Ridge field) Regional groundwater model Model domain limited to project area Time-varying constant head boundary condition used to represent well (rather than pumping/flow rates) for MODFLOW model; constant pumping rate used to represent well field in analytical model Model not calibrated Dual-phase flow, coal dual porosity and anisotropy, and geomechanical effects not included Coal seams not modelled independently of coal measures Vertical movement of groundwater not well constrained Aquifer confinement and interconnection simplified Effects of geological faults assumed insignificant Analytical modelling did not account for size of well Apparently no accounting of groundwater–surface water interaction Limited deterministic uncertainty analysis: Sensitivity analysis (four cases) for specific aquifer parameters and recharge for the MODFLOW model, and for storativity for the analytical model CSG well fields were modelled separately and cumulative impacts associated with other developments assessed on a qualitative basis Santos (2009a), Santos (2009b) Basin MODFLOW Regional groundwater model – CSG region divided into three subdomains (hydraulic compartmentalisation assumed) Time-varying constant head boundary condition Dual-phase flow, coal dual porosity and anisotropy, and geomechanical effects not included Coal not modelled independently of coal measures No consideration of rainfall recharge Simplified geology, homogeneous isotropic conditions Cumulative impacts not assessed None QGC (2009)
csg-modelling-groundwater-impacts.docx