CSG in Victoria
Geoff CollinsManager Energy Resources Development and Engagement
Presentation Overview:1. Context
2. What is CSG
3. How is it produced
4. Hydraulic fracturing
5. Water
6. Access to land
7. Prospectivity - how likely is CSG to eventuate
8. Questions
Context
• Victoria’s gas demand will have doubled by 2030
• Current gas reserves will be depleted somewhere between 2025 and 2030
• There are three possible sources of local supply which need to be
investigated:
Sources: AEMO Gas Statement of Opportunities
DPI Annual Statistical Review
• conventional gas offshore
• shale gas and tight gas onshore
• coal seam gas onshore
What is CSG?
CSG is methane, the principal component of natural gas. It is formed by:
CSG is largely held on the surface of the coal. The greater the hydraulic pressure, the more gas that can be stored.
• temperature as coal is buried (black coals)
• biogenic activity in coal (brown coals)
How is it produced?
• To produce CSG, pressure must be reduced to allow the methane to come off the coal surface
• Methane flows through natural fractures to a collecting well where it is brought to surface
• Depth is in the range of 200 to 1000 metres
• Drill rigs are truck mounted and occupy a space of about 60 by 80 metres
• Well spacing is of the order of 500 to 700 metres
• A producing well occupies a space of about 10 by 10 metres
Hydraulic fracturing
• Hydraulic fracturing or fraccing is used to enhance permeability where natural fractures are insufficient to allow gas to flow to the well
• Fraccing uses a fluid that is 98% water and sand. Wells are cased to contain the fracturing to the coal seam and to isolate shallower aquifers
• Victorian regulations mean any proposal for the use of additives in hydraulic fracturing requires detailed assessment
For a list of chemicals that might be used in fraccing fluids: www.appea.com.au
Water - sub-surface
Including
• lowering of (non-coal) aquifer pressures
• connection between aquifers
• natural connection
• connection caused by fraccing
• fraccing fluids
Water extraction requires licensing by SRW
Water - surface
Disposal of water
• disposal to land is exempt under EPA licensing
• disposal to an aquifer requires EPA licensing
• disposal to a waterway requires EPA licensing
Access to land
• Victoria wants to see both development of its earth resources and a thriving farming sector.
• The area that a CSG operation occupies means that farming activities can continue
• While there is no right of veto, the MRSDA puts requirements on companies that want to access land and provides a general requirement to consult
Prospectivity - how likely is it to eventuate?
• Most of the world’s CSG is coming from black coal
• Victoria largely has brown coal or disseminated black coal. Around Wonthaggi there are some thicker black coal seams but their extent is limited
• There is little information about the characteristics of Victoria’s coal from which to draw conclusions
• What evidence there is, is inconclusive.
Where Victorian brown coal is located
Questions?
Gippsland Basin CoalGippsland Basin Coal
CretaceousBlack Coal
Tertiary Brown Coal
Otway Basin Coal Otway Basin Coal
