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1 Coal Mining & CSG Extraction Overview of the Science Warwick Giblin FEIANZ Mining & CSG Law Conference Mudgee 17 th August 20 13,

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Presentation on theme: "1 Coal Mining & CSG Extraction Overview of the Science Warwick Giblin FEIANZ Mining & CSG Law Conference Mudgee 17 th August 20 13,"— Presentation transcript:

1 1 Coal Mining & CSG Extraction Overview of the Science Warwick Giblin FEIANZ Mining & CSG Law Conference Mudgee 17 th August 20 13,

2  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 2

3 Declared Wilderness Areas National Parks Current Mineral Titles Mineral Title Applications

4 Declared Wilderness Areas National Parks Current Mineral Titles Mineral Title Applications Current Coal Titles Coal Title Applications

5 Declared Wilderness Areas National Parks Current Mineral Titles Mineral Title Applications Current Coal Titles Coal Title Applications Current Petroleum Titles

6 Declared Wilderness Areas National Parks Current Mineral Titles Mineral Title Applications Current Coal Titles Coal Title Applications Current Petroleum Titles Petroleum Title Applications

7  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 ( ) 7

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12  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 12

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14  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 14

15  High pressure (7,000 psi) injection of water (about 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 15

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18  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 18

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21  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 21

22  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 22

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24  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 24

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26  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) 26

27  Construct any, without prior consultation and positive confirmation from the Tenement Holder: I. Buildings II. Sheds III. Yards IV. Dams V. Table Drains VI. 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 construction II. Install a pipeline over the Pipeline of the Tenement Holder to a depth greater than 200mm III. Farm over the Pipeline to a depth greater than 200mm IV. 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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29  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 29

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31  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 31

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33  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 33

34  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 34

35  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 35

36 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 publicenvironment scientific consensusburden of proof 36

37  1. Determine capacity of the natural systems especially hydrogeology  Goal: maintain long term sustainable resource use: a)Water resources/aquatic ecosystems b)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 37

38  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 38

39 Warwick Giblin Ph


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