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Coal Mining & CSG Extraction

Overview of the Science Warwick Giblin FEIANZ

Mining & CSG Law ConferenceMudgee

17th August 2013

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Social Science – humanistic & cultural aspects

Technical Science – facts & figures (environmental & economic)

JUSTICE Social = community & cultural respect &

recognition Environment = ‘where we live, work & play’ Economics = long term, include enviro & social

costs too + short term benefits

Declared Wilderness AreasNational ParksCurrent Mineral Titles Mineral Title Applications

Declared Wilderness AreasNational ParksCurrent Mineral TitlesMineral Title ApplicationsCurrent Coal TitlesCoal Title Applications

Declared Wilderness AreasNational ParksCurrent Mineral TitlesMineral Title ApplicationsCurrent Coal TitlesCoal Title ApplicationsCurrent Petroleum Titles

Declared Wilderness AreasNational ParksCurrent Mineral TitlesMineral Title ApplicationsCurrent Coal TitlesCoal Title ApplicationsCurrent Petroleum TitlesPetroleum Title Applications

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Agric: 3% of GDP; 12% if include ‘value add’ Mining: 9% of GDP Employment:- agric: 307,000 jobs- mining: 217,000 jobs 83% of mining profits accrued to foreign

investors (2009-10)

The Economy

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Coal & gas form in sedimentary basins Coal seam = naturally fractured, water saturated, with

methane adsorbed into the coal matrix Commenced 1996 in Aust. 10% of Aust’s gas needs Wells have steel casing & cemented in place Wells at ~ 700 m apart; 12 yr life 6,000 wells in Qld (predict 40,000) At surface the gas & water separated Produced water is salty (200-10,000 mgms/l NaCl) Produced water needs to be treated then various use

options Or reinjection into ‘non – useful’ aquifers

CSG Overview

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CSG taken 300 – 1,000m Freshwater aquifers usually < 200 m Coal seam holds water tight under pressure in the cleats &

fractures Construction of a well allows pressurised water to flow to surface The CSG is thus released from the coal micropores & fractures &

also flows to surface Are natural seeps of methane from coal seams via faults

Hydrogeology

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High pressure (7,000 psi) injection of water (about 0.2-0.6 ML water/well), sand and chemicals (3%) down a well into a coal seam

(Olympic pool =2.5ML) The pressure causes fractures in the coal, eg 10 m/minute then

slowing; up to 50 m away Sand holds fractures open allowing water & gas to flow The produced water and gas flow up the well to surface (only ~

50% of fracture fluid) About 50% of wells in Aust fracked to increase rate of gas flow Camden: produced 10 ML of water from all gas wells in 2012 Developed in 1940’s; > 1 mil fracking treatments in US

Hydraulic Fracturing

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Acid (HCl) Viscosity modifiers (eg guar gum) Friction inhibitors (eg petroleum distillates) Scale inhibitors (eg ethylene glycol) Corrosion inhibitors (eg methanol) Biocides(antibacterial agents) Citric acid

Fracking Chemicals

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In Qld Surat & sthn Bowen Basin: predict 175 GL/yr of produced water in 2020 (Klohn Crippen Berger, Qld Dept Nat Res & Mines 2012). SydHarb = 500 GL

In Qld the ave CSG well produces ~ 20,000 litres of water/day = 3 Olympic pools/yr (CSIRO 2012).

What to do with this salty water? If treated, what to do with the salt? And the water? Spillage of produced water into s/w or land G/w contamination (chemicals into g/w or create connections

between fresh & coal containing aquifers) Drawdown of groundwater Water extraction leading to extra stresses & subsidence With g/w extraction from a seam, other g/w will flow towards that

seam to re-establish steady state (10 yrs time?) Faults & fractures act as pathways for gas mvt End use: RO, stock, aquifer injection, aquaculture, industrial

Potential Water Impacts

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Well leakage (well integrity) - well construction & casing design g/w methane Fugitive methane emissions: leaks in production equip, pipelines &

processing say 2-5% of production Well casing cement may shrink over time allowing leakage Well integrity after decommissioning (cement) Alteration of land surface activities: roads, pipes, powerlines, gas

compressor stations, product water management systems, etc > 5 ha/well disturbance

Other Potential Impacts

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10,000 l wastewater spill in Pilliga State Forest (2011)

Qld Jan – June 2011:- 23 spills of produced water- 4 uncontrolled releases of produced water- 3 breaches of produced water storages due to flooding

Incidents

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Surface estate owner rights V licence holder extraction rights

Land access decisions Landholder technical, legal & negotiation skills Costs: time, legal, farm planning decisions Loss of privacy & peaceful enjoyment. Strangers 24/7 Socio-econ changes a la coal mining (higher paid

jobs, workforce changes) Transparency of decisions. Tradeoffs? Need independent agency for community to turn to

(GeoScience Aust/CSIRO)

Social Issues

Restricted activities include: Construct any, without prior consultation and positive confirmation from the Tenement Holder:

I. BuildingsII. ShedsIII. YardsIV. DamsV. Table DrainsVI. Irrigation Ditches

Install any troughs or tanks Drive trucks exceeding GVM of 10t over the Pipeline Area that is not on an existing track Drive machinery exceeding GVM of 10t over the Pipeline Area that is not on an existing track Undertake activities to carry out the following:

I. Construct a new track over the Pipeline. In this event, the Tenement Holder will specify requirements for any such track prior to constructionII. Install a pipeline over the Pipeline of the Tenement Holder to a depth greater than 200mmIII. Farm over the Pipeline to a depth greater than 200mmIV. Deep rip over Pipeline to a depth greater than 200mm V. Grade over Pipeline to a depth greater than 200mm VI. Drive along Pipeline trench with any vehicle VII. Remove Marker Posts

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Picture of deep hydrogeology unclear because >95% of g/w bores are <200m deep

Need ‘whole of basin’ baseline studies – picture of relationship between deep aquifers, fractures, faults & nearby strata

Understand g/w processes at depth, tectono-stratigraphic (geofabric) framework

Variables: Rock layers, faults, fractures, rate & direction of groundwater movement, connectivity of aquifers, barriers to g/w flow over depth, g/w quality

3D seismic studies/models from ‘basement’ to the land surface. Regular new data updates

Simulation modelling – whole of basin Measurement of background methane levels

Precautionary Principle

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Surface water & g/w changes & risks Dust Noise Night lighting Visual Traffic & road damage Infrastructure implications: housing, roads,

sewerage, etc Jobs & revenue FIFO Enviro, social & economic cost transfer risks

Open Cut Mining

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Surface water & g/w changes & risks Subsidence Coal bed methane management: power gen Traffic & road damage Infrastructure implications: housing, roads,

sewerage, etc Jobs & revenue FIFO Enviro, social & economic cost transfer risks

Underground Mining

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Mechanised shearers cut coal away whilst hydraulic-powered supports hold up the roof

Following removal of each slice of coal the supports progressively moved forward & roof is collapsed behind them

More efficient than bord-and-pillar method as does not leave behind pillars of coal, thus allowing a higher rate of extraction

Longwall mining

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Common technique in 1960s now in decline regular grid of mining tunnels &

progressively cutting panels into the seam whilst leaving behind pillars of coal to support the mine

Bord and pillar

If an action has a risk of causing harm to the public or the environment, in the absence of scientific consensus that the action is harmful, the burden of proof that it is not harmful falls on those taking the action

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Definition: Precautionary Principle

1. Determine capacity of the natural systems especially hydrogeology

Goal: maintain long term sustainable resource use:a) Water resources/aquatic ecosystemsb) Agricultural land c) Biodiversity – veg management

2. Regional land use planning based on values & risks of ALL the resource

3. Transparency in decision making, esp the tradeoffs being made

Precautionary Principle in Rural Land Use Management

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Defn: Measure of socio-political sentiment towards a project, company or industry

Co-ownership with trust & active support

Opposition where support withheld or withdrawn

Priority: improve human well-being & social equity, while reducing environmental risks

4. ‘Social Licence to Operate’/public welfare/environmental justice

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Warwick Giblin

wgiblin@bigpond.net.au

Ph 0419 271 819

www.ozenvironmental.com.au