Legacy product - no abstract available

Legacy product - no abstract available

No product available. Removed from website 25/01/2019

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

Natural gases from all of Australia's major gas provinces have been examined using their molecular and carbon isotopic compositions in order to define source, maturity and secondary alteration processes.

Natural gas is Australia's third largest energy resource after coal and uranium but despite this economic importance, the gas origin is not always recognized. To address this, isotope and geochemistry data have been collated on 850 natural gases from all of Australia's major gas provinces with proposed source ages spanning the earliest Paleozoic to the Cenozoic. Unaltered natural gases have a thermogenic origin ('13C methane ranges between -49 and -27'; 'D methane ranges between -290 and -125'). Microbially altered natural gases were identified primarily on the basis of 13C and D enrichments in propane and/or 13C depletion in methane and/or 13C enrichment in CO2. The carbon isotopic composition of the gas source has been estimated using '13C iso-butane as a surrogate for '13C kerogen while for gases where biodegradation is moderate to severe, '13C neo-pentane provides an alternative measure. The '13C kerogen of gas source rocks range from -47 to -22' with the older Paleozoic sources and marine kerogen amongst the most depleted in 13C. The '13C CO2 also provides an insight into crustal- and mantle-derived components while '15N N2 (-6.0 to 2.3' for N2 up to 47 %) distinguish between organic and inorganic (groundwater) inputs. This dataset provides a better understanding on the source and preservation history of Australian gas accumulations with direct implications on improving exploration success.

Restricted on advice from A. Barrett

February 2001 Bonaparte Basin - Gas Data The gas database contains molecular compositional and isotopic data for gases from the Bonaparte Basin as exported from AGSO's Orgchem database on 6th February 2001. The output represents those gases for which the data is considered not to be "commercial-in-confidence". Also included is a document which gives a description of the data fields. Copyright (C) Commonwealth of Australia, 2000.