An oil and gas resource reassessment of the Bonaparte Basin, Northwest Shelf of Australia

Bonaparte Basin is an established petroleum province in the Northwestern Australia shelf. The proven recoverable reserves of 2032 million barrels of oil equivalent (MMBoe) has recently exceeded the mean values of undiscovered resource estimates in previous studies, including that in the United States Geological Survey 2000 world assessment. There is a need for a re-assessment of the resource potential in this region. For the purpose of reassessment, this paper presents an overall review of the petroleum geology and discusses the key factors controlling hydrocarbon accumulations in the basin. A close examination of the petroleum system elements of the study area found fundamental differences in essential geological conditions, such as structure type, source rock maturity, trap integrity and preservation across the basin. These differences allow a subdivision of the Mesozoic Bonaparte Basin into the Malita and the Vulcan assessment units (AUs). The undiscovered resource potential in the two AUs are estimated using a Monte Carlo simulation procedure developed by the USGS in their 2000 world petroleum resource assessment. Our study shows that the Bonaparte Basin contains 938 million barrels of oil, 1901 million barrels of condensate and 34.423 trillion cubic feet of natural gas yet to be found (mean estimates), which are much greater than the previous assessments.