Underground frontiers

A number of coal seam gas (CSG) and shale gas discoveries in Queensland, South Australia and Western Australia were announced in June.

Comet Ridge Hergenrother 1 and Gunn 1 CSG exploration wells in Queensland encountered significant sections of coal and shale with encouraging preliminary gas content.

Comet Ridge managing director, Tor McCaul said he was very encouraged by the preliminary gas content and drillstem test results from the Hergenrother 1 well. Core laboratory work will define the final coal parameters. The Gunn 1 CSG exploration core well in the Galilee Basin encountered a significant section of coal and shale and the preliminary results from Gunn 1 are consistent with results from Hergenrother 1. The company will move into the next phase of its core well programme analysing core well data gathered over the past months.

“Any potential pilot scheme is likely to be located in this general area of the Comet Ridge acreage, however, more technical work will be required over the coming months before a decision on a pilot production scheme is made,” Mr McCaul said.

Australia Pacific LNG’s Gladstone project centre was officially opened in June by Queensland Premier, the Hon. Anna Bligh. The Premier was joined by Origin managing director, Grant King and ConocoPhillips president and chief operating officer, John Carrig at the official opening of the centre.

The centre has a dual purpose, as an office for project employees, as well as being an education centre for the Gladstone section of the Australia Pacific LNG project.

The CSG to liquefied natural gas (LNG) project is a 50:50 joint venture between Australian-based Origin and US oil and gas producer ConocoPhillips. The project will stretch from the gas fields in the Surat and Bowen Basins, along a 450 km pipeline, to an LNG facility on Curtis Island off Gladstone.

Premier Anna Bligh said the Australia Pacific LNG project was at the forefront of a major new industry for Queensland.

“Our Government is serious about facilitating the LNG industry and realising the thousands of jobs it offers in Gladstone and right throughout the Surat Basin,” she said.

“This centre will be a place for employees but also a place for the public to learn more about what this industry has to offer the region.

“I am delighted to see our LNG industry becoming a reality. This sustainable new industry has a lot to offer Queensland and I am excited for the future of LNG in this state.”

In South Australia a technical review by Stuart and Denver-based unconventional gas experts, MHA Petroleum Consultants’, showed two significant areas in its recently-granted tenement PEL516 in the Southern Cooper Basin – the Allunga Trough and the Mettika Embayment – hold considerable potential for the identification of major resources of shale gas.

In these localities the Permian-aged Roseneath and Murteree Shales are well developed and at moderate depths, conditions which are conducive to the development of relatively high-value high-methane gas content (low carbon dioxide content) with high levels of contained gas-liquids. Also, gas in these strata is likely to prove noticeably less expensive to develop than in other, deeper, sectors of the Cooper Basin.

Stuart’s March quarterly report states its Cooper Basin tenements have potential to contain in excess of 20 trillion cubic feet of coal-hosted gas-in-place, Stuart share, principally in Stuart’s northern tenements.

In Western Australia, New Standard Energy noted a number of significant advances and developments for its exploration efforts in the Canning Basin. The developments include a new independent report confirming the large shale gas resource potential of the Goldwyer Basin in the Canning Basin together with the execution and announcement of a significant farm-in agreement by Buru Energy, worth more than $150 million, for exploration acreage directly adjacent to New Standard’s exploration area in the Canning Basin.

New Standard managing director, Sam Willis said the combination of the RISC and NSAI reports together with Mitsubishi’s investment of over $150 million in Canning Basin hydrocarbon exploration provided vindication of New Standard’s continued pursuit of its exploration strategy in the Canning Basin.

“We are delighted that major, credible, independent groups are assessing and recognising the hydrocarbon opportunities in the Canning Basin,” Mr Willis said.

“The RISC review provides another third party view regarding the potential of the Goldwyer shale as a prospective shale gas play. RISC has undertaken this work completely independently and their views confirm what we have been stating for some time – that although early stage, the Goldwyer shale has the potential to host a substantial onshore gas resource,” he said.

In Western Australia’s mid-west, Cougar Energy signed a binding term sheet with Eneabba Gas in June to form an unincorporated joint venture for the development of a UCG and power station project.

The binding term sheet came after Cougar Energy signed a letter of intent involving the development and commercialisation of a UCG project in China’s inner Mongolia autonomous region.

In late June Cougar Energy managing director, Dr Len Walker followed up with a visit to Shanghai for a presentation to Chinese guests at the Queensland-China Trade and Investment Project Information Seminar as part of the Queensland Government’s Trade and Investment Mission to China for the Energy and Resources Sectors.

Cougar Energy’s presentation states it has three projects in preliminary discussions for Mongolia and welcomed investment enquiries for its company, its Australian Kingaroy power project and developing its China UCG projects.


 

An assessment of the uranium and geothermal potential of North Queensland

By DL Huston and contributors, Geoscience Australia

As part of the Onshore Energy Security Program, Geoscience Australia has undertaken a series of energy potential assessments, both on a national scale and on a regional scale in association geological framework studies. These framework studies, which are designed to provide information on geodynamic and architectural controls on energy systems, are linked to the acquisition of deep seismic, magnetotelluric and airbourne electromagnetic data. The focus of fiscal year 2008-2009 was north Queensland, stretching from the Northern Territory border to the coast, between 17° and 22° south latitude.

In addition to the seismic data acquisition and interpretation, these framework studies have included geochronological studies as well as uranium mineral system and geothermal system studied in collaboration with the uranium and geothermal projects. The main goal of these studies is to provide background data that can be used by industry for exploration, however the data also provide new information that can be used in assessing the potential of north Queensland for uranium and geothermal resources using geosystems (i.e. mineral and geothermal systems) methodologies in a GIS environment. This report provides such an assessment in a qualitative to semi-quantitative way. One of the goals of this analysis is to define the extent of areas or regions with known deposits; another goal was to define areas with previously unrecognised potential.

The uranium and geothermal energy potential of north Queensland has been assessed using a geosystems approach as part of the Federal Government’s Onshore Energy Security Program.

Four types of uranium mineral systems are known to have produced significant uranium-bearing deposits in north Queensland: unconformity-related deposits (Westmoreland), including deposits traditionally classified as volcanic-related metasomatic deposits (Mount Isa uranium field); uranium-bearing iron oxide copper-gold deposits; and magmatic-hydrothermal deposits (Mary Kathleeen). In addition, sandstone-hosted uranium mineral systems may have produced uranium accumulations in the Mesozoic to Cenozoic Eromanga and Carpentaria basins based on analogies with the Frome Embayment in South Australia.

Based on the characteristics of known deposits and the geology of north Queensland, a modified pmd*CRC five-questions approach to mineral system analysis was used to identify areas considered to have potential for uranium mineralisation. This analysis identified known uranium districts and identified other areas as having significant potential.

Three areas were identified as having significant potential for sandstone-hosted deposits in the Eromanga and Carpentaria Basins:

• an area east of Cloncurry;

• an area 90 km north of Hughenden; and

• an area around the township of Richmond.

Parts of the Burdekin Basin and immediately underlying units were identified as having potential for unconformity-related deposits. Outside of known uranium districts, the following areas were identified as having greatest uranium potential within Proterozoic and Paleozoic rocks:

• extensions of the Mount Isa uranium field to the north and south along bounding faults to the Leichhardt River Fault Trough (for unconformity-related and metasomatic uranium deposits);

• extensions of the Cloncurry iron-oxide copper-gold district undercover to the south and, particularly, to the north along the inferred eastern boundary of the Mount Isa province (for uranium-rich iron oxide copper-gold deposits); and

• a 50 x 200 km long, north-west trending belt southwest of Cairns (for metasomatic and/or iron-oxide copper-gold deposits).

Although other areas were also identified in the analysis as having potential, those listed above are considered most prospective in that they either extend known districts under cover or were identified independently by analysis of more than one uranium system. As a check on the veracity of the process, our analysis also identified known uranium districts as having high potential.

A systems approach has also been applied to assess the geothermal potential of north Queensland. Although no geothermal systems have yet been commercially developed in north Queensland, theoretical considerations and analogies with systems in South Australia and elsewhere were used to identify essential elements for geothermal systems. Prospectivity assessments for ‘hot rock’ and ‘hot sedimentary aquifer’ systems identified similar geographic areas with high potential, including the Millungera Basin, the Eromanga Basin, the north-west part of the Carpentaria Basin, near Burketown, the north-central Drummond Basin, and the Galilee Basin.