GISERAs water research projects in northern NSW 1. Impacts of CSG - - PowerPoint PPT Presentation

▶
gisera s water research projects in northern nsw
SMART_READER_LITE
LIVE PREVIEW

GISERAs water research projects in northern NSW 1. Impacts of CSG - - PowerPoint PPT Presentation

Feb 22, 2024 168 likes •473 views

GISERAs water research projects in northern NSW 1. Impacts of CSG depressurisation on the Great Artesian Basin (GAB) flux [ Sreekanth et al, CSIRO Land and Water, Jun 18] 2. Data-worth and spatial design of groundwater monitoring network

slide-1
SLIDE 1

GISERA’s water research projects in northern NSW

1. Impacts of CSG depressurisation on the Great Artesian Basin (GAB) flux [ Sreekanth et al, CSIRO Land and Water, Jun 18] 2. Data-worth and spatial design of groundwater monitoring network in the Narrabri Gas Project area [Sreekanth et al, CSIRO Land and Water Mar 18] 3. Improving the representation of the impact of CSG in groundwater models [ Connell et al, CSIRO Energy Nov 18]

GISERA water research NSW| 30 Aug 2018 | 1

slide-2
SLIDE 2

Impacts of CSG depressurization on Great Artesian Basin flux

Sreekanth Janardhanan, Trevor Pickett, Dennis Gonzalez, Tao Cui, Mat Gilfedder, David Rassam, Matthias Raiber, Axel Suckow, Kate Holland, Damian Barrett, Dan O’Sullivan, Alec Deslandes, Helen Beringen, Nicola Proctor 30 August 2018

slide-3
SLIDE 3

Stratigraphy

3

Inter-burde den 2 Inter-burde den 1

GISERA water research NSW| 30 Aug 2018 |

slide-4
SLIDE 4

4 GISERA water research NSW| 30 Aug 2018 |

Basin Formation type Model layer Zone 1 Namoi alluvium alluvium 1 - 2 Zone 3 Surat Basin Inter-burden 3 - 5 Zone 6 Surat Basin Pilliga Sandstone 6 Zone 8 Gunnedah Basin Interburden 7 – 9; 11 - 13 Gunnedah Basin Coal 10, 14

Conceptualisation in the numerical model

slide-5
SLIDE 5

5 |

Objectives

  • Measurement and analysis of new

environmental tracers and hydrochemistry data to improve conceptual understanding

  • f recharge
  • Integrating the knowledge derived from

new data and ongoing work (OWS projects BA, FAM) into the conceptual understanding of the Surat and Gunnedah basins

  • Predictive analysis of potential impacts of

CSG development on drawdown and GAB fluxes

  • Use the predictive uncertainty anlysis to

inform data-worth and monitoring strategies

GISERA water research NSW| 30 Aug 2018 |

slide-6
SLIDE 6

Groundwater model built for the Namoi Bioregional Assessments

6 | GISERA water research NSW| 30 Aug 2018 |

Groundwater modelling for the Namoi subregion (Sreekanth et al, 2018)

slide-7
SLIDE 7

Probabilistic modelling approach for a generic CSG development scenario

  • Water production rates

are not hard-wired as a boundary condition in the model

  • Instead, the model

simulates the water production for a given depressurization target

  • Accounts for the

uncertainty in CSG water production

7 | GISERA water research NSW| 30 Aug 2018 |

slide-8
SLIDE 8

Sensitivity analysis

8

Vertical hydraulic conductivity of the inter-burden layers: most sensitive parameter that influences the propagation of depressurization upwards into the Pilliga Sandstone

GISERA water research NSW| 30 Aug 2018 |

slide-9
SLIDE 9

Conceptualisation of hydraulic properties

9 GISERA water research NSW| 30 Aug 2018 |

Observed depth-dependency and spatial variability from core, DST, packer and pump test data ( Aryal et al, 2018; Turnadge et al, 2017, Sreekanth et al, 2018)

slide-10
SLIDE 10

Inter-burden hydraulic properties

GISERA water research NSW| 30 Aug 2018 | 10

AQUIFER Santos GIA

Vertical hydraulic conductivity of the numerical model layer 7 immediately underneath the Pilliga Sandstone ( Purlawaugh formation)

AQUTARD

slide-11
SLIDE 11

Spatial variability of vertical hydraulic conductivity in the inter- burden layer 8

11 GISERA water research NSW| 30 Aug 2018 |

slide-12
SLIDE 12

Key findings – CSG induced GAB Flux changes

12

(a) (b)

GISERA water research NSW| 30 Aug 2018 |

slide-13
SLIDE 13

Predicted CSG impacts to water volumes in the GAB aquifer

1 3 |

Volume (GL/y) Source Estimated Recharge (GAB NSW Total) 295 BRS report (Habermehl, 2009) Estimated recharge Southern Recharge Source (SRS) 42.4 NSW Water Sharing Plan Lont-term Annual Average Extraction Limit (LTAAEL) 29.68 NSW Water Sharing Plan Stock and domestic use 3.0 NSW Water Sharing Plan Unlikely that the maximum CSG flux impact in any year will exceed 2.3 This study Likely that the maximum CSG flux impact will be around 0.06 This study Likely that CSG flux impact will be more than 0.0001 This study

GISERA water research NSW| 30 Aug 2018 |

0.27 0.06 0.0001 50 100 150 200 250 300 350 Recharge (GAB NSW total) Estimated recharge (SRS) LTAAEL Stock and Domestic right estimate 95% precited maximum CSG flux impact Median of predicted maximum CSG flux impact 5% predicted maximum CSG flux impact Water volume (Giga litre/year) Other estimates Highly parameterized model Parsimoniously parameterized model

3 29.68 42.4 295

slide-14
SLIDE 14

Conclusion - 1

  • Depressurization of coal seams could potentially induce small

changes in groundwater flux from the GAB aquifer to deeper formations

  • The median value of the predicted maximum flux losses is 60

ML/year which is about 0.2 % of the Long-term Annual Average Extraction Limit set for the the Southern Recharge Source.

14 GISERA water research NSW| 30 Aug 2018 |

slide-15
SLIDE 15

Data-worth and spatial design of groundwater monitoring network in the Narrabri Gas Project area

Sreekanth Janardhanan, Dan Gladish, Trevor Pickett, Dennis Gonzalez, Dan Pagendam, Tao Cui, Mat Gilfedder, David Rassam, Damian Barrett, Dan O’Sullivan, Helen Beringen, Nicola Proctor 30 August 2018

slide-16
SLIDE 16

Method overview

16

START Flow model (MODFLOW USG) Particle tracking Mod-PATH3DU Drawdown in model layers Travel times, distances, velocities Geostatistical spatial models Baseline WQ variance Optimal monitoring design(s) Data worth analysis STOP MODELS MONTE-CARLO SIMULATIONS LINEAR ANALYSIS GLOBAL OPTIMIZATION

GISERA water research NSW| 30 Aug 2018 |

slide-17
SLIDE 17

GISERA water research NSW| 30 Aug 2018 | 17

Maximum drawdown impacts

slide-18
SLIDE 18

Travel distances within a modelling period

  • f 100 years

GISERA water research NSW| 30 Aug 2018 | 18

slide-19
SLIDE 19

Ensemble predictions to inform potential future monitoring locations to

  • bserve CSG-induced drawdown

19

Layer 6 Layer 7 Layer 12 Dmax – Maximum CSG-induced drawdown Tmax – Time at which maximum CG-induced drawdown occurs

GISERA water research NSW| 30 Aug 2018 |

slide-20
SLIDE 20

Monitoring network design

  • Monitoring within

predicted drawdown area to verify and refine the predictions

GISERA water research NSW| 30 Aug 2018 | 20

Monitoring network used in data-worth analysis Potential monitoring bore sites

slide-21
SLIDE 21

Current GAB monitoring bores within the predicted drawdown area

  • Current density of

montoring bores ~4.2 bores/100 km2

GISERA water research NSW| 30 Aug 2018 | 21

slide-22
SLIDE 22

Receptor locations for data-worth analysis

GISERA water research NSW| 30 Aug 2018 | 22 GISERA water research NSW| 30 Aug 2018 |

slide-23
SLIDE 23

Data worth of observations

23

a

GISERA water research NSW| 30 Aug 2018 |

slide-24
SLIDE 24

Conclusion – 2

  • Probabilistic predictive analysis resulted in a median predicted

drawdown to be less than 0.2m for most of the areas within and beyond the gas project area

  • Probabilistic particle tracking analysis indicated that velocity of

groundwater flow in the Pilliga Sandstone aquifer is slow and particles may travel on the order of 100s of metres within a simulation period of 100 years.

  • The current density of GAB monitoring bores is approximately 4.2

bores/100 km2

  • Data-worth analysis indicated that nested monitoring bores within the

95th percentile drawdown area and especially monitoring formations underneath the Pilliga Sandstone returns maximum data-worth

  • A design for a network of 10 bores and the data-worth emerging from

that is demonstrated in this study

24 GISERA water research NSW| 30 Aug 2018 |

slide-25
SLIDE 25

IESC advice to decision maker on Narrabri Gas Project –gaps addressed by GISERA study

25

IESC comment number GISERA research Q1.2, Q1.13, Q2.15 Improve confidence in modelled heads in target seams instead of specified flux boundary condition for coal seasm gas Used target heads in coal seams/formations (projects 1). Project 3 will help to refine this further Q1.3, Q1.6f Groundwater model parameterisation, calibration, uncertainty and sensitivity analysis. Monitoring points for data collection could be identified based on uncertainty analysis Investigated two different parameterisation schemes, undertook calibration, sensitivity and uncertainty analysis (projects 1 and 2) Q1.6b, 2.17 “measuring heads directly above and below tightest aquitards would allow constrain aquitard properties” Our monitoring design study (project 2) establishes this using quantitative analysis that multi-level piezometers would be most useful in refining predictions

GISERA water research NSW| 30 Aug 2018 |

slide-26
SLIDE 26

26

IESC advice to decision maker on Narrabri Gas Project –gaps addressed by GISERA study

IESC comment GISERA study Q1.6d Consideration should be given to use methods like Turnadge et al (2017) in assessing effects of changing permeability and storativity particularly in areas with

  • verlying sensitive receptors

We have used the data/knowledge from Turnadge et al and have assessed the drawdown effects from varying permeability and storativity in the uncertainty analysis Q1.6e “range of different hydrogeological conceptualisations and methods to address uncertainties in recharge” In this study we used environmental tracers to understand recharge. We also evaluated wide range of variabilities in recharge in the model while predicting the impacts Q1.6h “robust estimates of evapotranspiration in the model” We have spatially varying evapotranspiration considering vegetation height

GISERA water research NSW| 30 Aug 2018 |

slide-27
SLIDE 27

Thank you

Sreekanth Janardhanan Senior Research Scientist t +61 7 3833 5565 e Sreekanth.janardhanan@csiro.au w gisera.org.au

slide-28
SLIDE 28

Acknowledgements

  • Jizelle Khoury
  • Henning Prommer
  • Catherine Moore
  • Ryan Morris
  • Andrew Moser
  • Saeed Torkzaban
  • Raman Pandurangan
  • Luke Connell
  • Melita Keywood
  • Andrea Walton
  • Helen Beringen
  • Dan O’Sullivan
  • Nicola Proctor
  • Russell Crosbie
  • Luk Peeters
  • Glenn Toogood
  • John Doherty
  • Liz Tearall
  • David Rassam
  • Neale House
  • Sue Hamilton
  • Jim Underschultz
  • Tim Ransley
  • Steven Flook
  • Cate Barrett
  • Andrew McCallum
  • Andrew Druzynski
  • Fabienne d’Hautefeuille
  • Phil Davies
  • Tim Ransley
  • Emily Slatter
  • Jessica Northey
  • Keith Phillipson
  • Researchers of the Bioregional Assessment Programme
  • David Post

GISERA water research NSW| 30 Aug 2018 | 28