Gas in Victoria
In Victoria, gas may be found in three broad areas. These are known as sedimentary basins and are named after the areas they cover: the Gippsland Basin, the Otway Basin and the Murray Basin. The basin boundaries are defined on the basis of their geology – they contain layers of sedimentary rocks (e.g. sandstones and shales) that have been deposited, buried, compacted; and in most cases folded and faulted by movement within the Earth’s crust over many millions of years.
Offshore and onshore conventional gas
Victoria’s Gippsland and Otway sedimentary basins have an onshore and an offshore component. Exploration for oil and gas has happened for around 100 years in the onshore Gippsland and Otway basins. However, the majority of oil and gas discoveries and production to date have been from the offshore Gippsland and Otway basins. Relatively small amounts of gas have been produced from conventional traps in the onshore Otway Basin. One of these traps is now used to store gas at Port Campbell; the Iona Gas Plant.
There has been some exploration for coal seam and tight gas in the onshore Gippsland and Otway basins. A retention lease for onshore gas is currently in place over the Seaspray area. No commercial discoveries of shale or coal seam gas have been made in Victoria to date.
Gas use by sector
The consumption of natural gas by sector in Victoria as at 2012-13 is:
|Sector||Petajoules (PJ)||Percentage of total|
|Construction, Transport and Agriculture||4.2||1.5%|
|Victoria consumed 287.2 petajoules of gas|
|1.82 million residential customers|
|56,000 business customers|
Source: Essential Services Commission, 2014, Energy Retailers Comparative Performance Report – Customer Service 2013-14, p.8