Australia has major gas shale potential in four main assessed basins and may have
additional potential in other basins. With geologic and industry conditions
resembling those of the USA and Canada, the country appears poised to commercialize its gas shale resources on a large scale. The Cooper Basin,
Australia’s main -onshore gas-producing basin, could be the first to develop. Other prospective shale basins in Australia include the small, scarcely explored Maryborough Basin in coastal Queensland, which contains prospective Cretaceous-age marine shales that are over-pressured and appear gas saturated. The Perth Basin in Western Australia, undergoing initial testing by AWE and Norwest Energy, has prospective marine shale targets of Triassic and Permian age. Finally, the large Canning Basin in Western Australia has deep, Ordovician-age marine shale that is roughly correlative with the Bakken, Michigan, and Baltic basins. These basins hold an estimated total 396 Tcf of technically recoverable shale gas resources,
COOPER BASIN (SOUTH AUSTRALIA AND QUEENSLAND)
Straddling the South Australia and Queensland border, the Cooper Basin has been Australia’s main onshore gas supply region for the past several decades. Current production from the basin is about
0.5 Bcfd of natural gas from conventional and low-permeability reservoirs. Within the basin, the Nappamerri Trough contains thick, over pressured and organic rich shales at prospective depth, as well as extensive deep coal deposits. Gas pipelines connect the basin to Sydney and other urban markets in
eastern Australia. With extensive tight sandstone gas production, the basin has service industry capability for advanced hydraulic fracturing that could be adapted for developing gas shale reservoirs.
Basin is Australia’s largest onshore oil and gas production region. Oil and gas development began in the basin during the 1960’s, while hydraulic fracturing of low permeability formations began in 1968 and has been extensively used since. More than 400 wells have been hydraulically stimulated in the Cooper basin to date, though the jobs were much smaller (typically 50,000 lbs sand with 50,000 gal fluid) than used in modern horizontal shale wells. Nevertheless, the Cooper basin has Australia’s best capabilities for fracking shale reservoirs. Current production from conventional and tight formations in the basin totals nearly 600 Mcfd from 700 gas wells and 2,500 bopd from 50 oil wells. The Cooper Basin also
has been Australia’s most active area for gas shale leasing and testing. Santos, Beach Energy, and Drill Search Energy have active shale evaluation programs, though only Beach is known to have drilled a test well. Starting in October 2010 Beach drilled and completed a vertical shale test well in the eastern Nappamerri Trough, thought to be Australia’s first dedicated shale test well. Drilled to a total depth of 3,612 m, the well penetrated 393 m of REM shale formation with continuous gas shows. The company is analyzing five REM cores for gas content and mechanical properties. Beach plans to conduct an 8-stage frac of the Encounter-1 test well during 2Q-2011.
MARYBOROUGH BASIN (QUEENSLAND)
This small basin in coastal southern Queensland, located about 250 km north of Brisbane, has two potential gas shale targets within the Cretaceous Maryborough Formation. Only five conventional oil & gas exploration wells have been drilled in the Maryborough Basin. No shale activity has been reported.
PERTH BASIN (WESTERN AUSTRALIA)
The Perth Basin is a petroleum producing region that extends on and offshore in the southwest of Western Australia. It contains two main organic-rich shale formations with gas development potential:
the Permian Carynginia and Triassic Kockatea shales, portions of which already produce oil and gas from conventional reservoirs. Local operator AWE is evaluating the shale potential over approximately 1 million gross acres. AWE and partner Norwest Energy have cored these shale targets and may fracture stimulate a shale well in the basin during 2011. Approximately 100 petroleum exploration wells have been drilled in the onshore Perth Basin, resulting in the discovery of six conventional natural gas fields, all located within the Dandaragan Trough in the north. Proved reserves to date total about 600 Bcf with
small amounts of associated oil, found in the main conventional reservoirs.
CANNING BASIN (WESTERN AUSTRALIA)
The large and scarcely explored Canning Basin in northwestern Western Australia has emerging potential in several organic-rich shales, including the Laurel, Lower Anderson, and Goldwyer shales,
though their potential remains poorly defined. Several conventional and tight gas discoveries have been made in the basin, though not developed due to lack of gas pipelines, indicating that source rocks here may be mature. Buru Energy (with partner Mitsubishi) and New Standard Energy hold most of the leases in this area and currently are evaluating the basin’s shale potential.
NATURAL GAS PROFILE
Australia produced 1.5 Tcf of natural gas in 2009, though only consumed 0.94 Tcf. Much of the gas in converted into LNG to be distributed domestically and exported to Asian markets. As of January 2010,
Australia’s estimated proven natural gas reserves is approximately 110 Tcf.
Source: eia U.S. Energy Information Administration, April 2011, World Shale Gas Resources: An Initial Assessment of 14 Regions Outside the United States http://www.eia.gov/analysis/studies/worldshalegas/