Terramin Australia Limited · ASX:TZN
Terramin Australia — Technical Presentation (October 2016)
31 slides from Terramin Australia's technical presentation, October 2016
Slide 1: Australian Groundwater Technologies “making water work”
Australian Groundwater Technologies “making water work”
Slide 2: Groundwater models and their uses
Groundwater models are computer models of groundwater flow systems. The model will be used as a tool to: • Represent the current state of groundwater. • Predict the rate of groundwater inflows into the mine. • Assess the groundwater impacts to surrounding bores. • Evaluate water management options a
Slide 3: Model confidence classes 1, 2 and 3
Class 1 Class 2 Class 3 • Limited information • Greater information • Basic inputs • Tested inputs • Not calibrated • Calibrated • Low confidence • High confidence 2012 Australian groundwater modelling guidelines, Waterlines report, National Water Commission, Canberra Australian Groundwater Technolo
Slide 4: Development stages
Development stages 1. Conceptualisation of the aquifer system (based on the focused drilling investigations and regional bore census) 2. Model construction 3. History matching (model calibration) 4. Predictions (mining scenarios) 5. Sensitivity & uncertainty analysis Conceptualisation > Model constr
Slide 5: Model inputs and information used
Model inputs Information used to construct the model Model Boundaries (Catchment inflow & outflow) Groundwater flow pattern derived from 48 wells Aquifer Properties Derived from 12 pumping tests • Site geological model based on exploration holes Aquifer geometry • Structural elements based on geophy
Slide 6: Conceptualisation of hydrogeological processes
• Conceptualisation (hydrogeological processes) • Groundwater flow pattern • Groundwater discharge (pumping) • Groundwater recharge (rainfall) • Groundwater & surface water interactions • Aquifer geometry & faults • Aquifer properties Australian Groundwater Technologies “making water work”
Slide 7: Groundwater flow pattern for Winter & Summer
• Groundwater flow pattern for Winter & Summer Woodside BiH Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 8: Groundwater discharge (pumping)
• Groundwater discharge (pumping) Woodside BiH Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 9: Groundwater rainfall recharge rates
• Groundwater rainfall recharge rates (mm/y) Woodside BiH Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 10: Groundwater - surface water interactions and the role of springs
• Groundwater - surface water interactions and the role of springs BiH Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 11: Groundwater & surface water interactions - Winter
• Groundwater & surface water interactions - Winter Inverbrackie Creek Woodside Land surface elevation Groundwater elevation during winter Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 12: Groundwater & surface water interactions - Summer
• Groundwater & surface water interactions - Summer Land surface elevation Groundwater elevation during summer Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 13: Aquifer geometry & faults
• Aquifer geometry & faults GROUND SURFACE COX SANDSTONE FRACTURE MARBLE Australian Groundwater Technologies “making water work”
Slide 14: Aquifer geometry & faults – regional scale
• Aquifer geometry & faults – regional scale North Marble BiH Woodside Faults Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 15: Aquifer geometry & faults – cross section
• Aquifer geometry & faults – cross section Australian Groundwater Technologies “making water work”
Slide 16: Aquifer geometry & faults – cross section
• Aquifer geometry & faults – cross section SE NW Groundwater level - Completely weathered – Altered to clay - - Highly weathered – Altered to clay – original rock textures recognizable - Moderately weathered – Partly altered but some original minerals Australian Groundwater - Weakly Weathered – Ver
Slide 17: Aquifer permeability tests
• Aquifer permeability tests Investigation bores Pumping tests conducted on: • Marble • Fracture zone • Tapley Hill Fm • Cox sandstone • 7 private wells Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & unc
Slide 18: Aquifer testing
• Aquifer testing What was monitored? • GWLs monitored in: − 12 site bores; − 22 private bores; − WL loggers installed in site bores and some private bores. • Barometric pressure. Australian Groundwater Technologies “making water work”
Slide 19: Aquifer testing
• Aquifer testing 0 PRIVATE BORES 5 10 PUMP OFF 15 DTW (m) PUMP ON 20 25 30 35 40 12/08 14/08 16/08 18/08 20/08 22/08 PERCHED WT Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 20: Model construction
• Model Construction • Topography • Model Layers (aquifers) • Boundaries • Assign aquifer properties • Assign gw recharge (rainfall) • Assign gw discharge (pumping bores) • Inverbrackie Creek (recharge / discharge) Australian Groundwater Technologies “making water work” Conceptualisation > Model con
Slide 21: Topography, model layers, boundaries
• Topography • Model Layers • Boundaries Australian Groundwater Technologies “making water work”
Slide 22: Assign aquifer properties
• Assign Aquifer Properties > refer to model Example Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 23: Model calibration
Model Calibration: • A process where model inputs such as aquifer properties are adjusted until model predictions fit historical measurements. • Ensures the model can be accepted as a good representation of the real system. • Prepares the model for use during predictions of future behavior. Australi
Slide 24: Calibrations performed
Calibrations performed include: Steady state calibration 1.Regional groundwater flow pattern Transient calibrations 2. Pumping test 3. Seasonal pumping & groundwater level decline 4. Anecdotal information - pumping of the BiH mine Australian Groundwater Technologies “making water work” Conceptualisa
Slide 25: Modelled versus measured groundwater levels
1. Modelled versus Measured groundwater levels BiH Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 26: Transient calibration - pumping test
2. Transient Calibration - Pumping test Pump Test Time (Days) 0 1 2 3 4 5 0 Groundwater level drawdown (m) 2 4 Measured GWL 6 during pump test 8 10 12 14 Modelled GWL 16 (calculated) 18 DWIB4 Calc DWIB4 Obs DWIB1 Calc DWIB1 Obs DWIB2 Calc DWIB2 Obs DWIB3 Calc DWIB3 Obs DWIB5 Calc DWIB5 Obs BH16 Calc
Slide 27: Transient calibration – seasonal groundwater decline
6628-10199 385 380 RSWL 375 3. Transient Calibration – Seasonal 370 365 groundwater decline (m) due to pumping 2/03/14 18/09/14 6/04/15 23/10/15 10/05/16 26/11/16 420 6628-8937 415 RSWL 410 405 400 18/09/14 23/10/15 10/05/16 26/11/16 2/03/14 6/04/15 410 6628-8945 Woodside 405 RSWL 400 395 BiH 390 38
Slide 28: Anecdotal calibration
• Pumping commenced on 17th January 1891 (40 to 60 L/s). 4. Anecdotal • Mine manager noted ‘’In March deepening of the Victoria Shaft below 5 level commenced. On the 23rd May the groundwater level was noted at 18 feet below 5 level (equating to ~113 m) on that day the water levels since pumping bega
Slide 29: Incorporating the proposed mine plan
Incorporate proposed mine planto predict groundwater inflows and groundwater impacts: • without mitigation • with mitigation Marble Mine plan Australian Groundwater Technologies “making water work” Conceptualisation > Model construction > History Matching > Predictions > Sensitivity & uncertainty
Slide 30: Modelling timeline
2 years 3.5 years Australian Conceptualisation Groundwater > Model construction Technologies > History “making water work” Matching > Predictions > Sensitivity & uncertainty
Slide 31: Sensitivity & uncertainty analysis
• Sensitivity & uncertainty analysis • Undertaken to assess the robustness of the model • Alter aquifer properties (higher or lower) • Add, remove or adjust groundwater flow boundaries • Interception of major fracture during mining Australian Groundwater Technologies “making water work” Conceptualis
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