January 2008 Technical Meeting
Thursday 24th January at 5:30pm
at 175 Elizabeth Street,
Brisbane
COST: ASEG Members $5 - Students Free
Soft drinks, beer, wine, and finger food provided for attendees
Schedule:
5.30 Pre-Presentation Food and Drinks.
6.00 Technical Presentation – Finding More Oil in the Gippsland Basin
About the Presentation:
Every oil company desires to predict the most likely locations of yet-to-be-discovered oil pools.
General Systems and Complexity Theories allow us to do just that.
The current approach of blanket seismic, magnetic and gravity exploration of basins reveals a multitude of traps.
However, generally only 5% (or less) of those traps ultimately are found to contain oil or gas. Why only 5%?
General Systems and Complexity are critical to any understanding we might have in respect to that 5%.
These theories have proven to be useful in predicting where to explore for more oil in the Gippsland Basin.
Predictions made in 1980 have been especially accurate. The spatial distribution of oil pools is radial
with the individual, emergent pattern having a diameter of ~100 km. Multiple pattern recognition techniques were employed.
It is proposed that these radial patterns originate from Rayleigh-Bénard convection in the mantle.
At the Rayleigh Number appropriate for the mantle, the stable planform is the spoke pattern,
where hot mantle material is moving upward near the centre of the pattern and outward along the radial arms.
It is accepted that an increase in temperature is required to convert buried, ancient vegetation into kerogen
and ultimately into oil and gas. Generally the temperature increase is considered to be adiabatic.
The ‘oil window’ is thought be 130° to 150°C, which translates adiabatically to a depth of 4,000 to 5,000 metres.
The delineated radial distribution of oil pools in the Gippsland Basin indicates that the genesis of oil
is supra-adiabatic with the increased temperature a consequence of increased heat from the mantle.
An increase of only 10°C can double the reaction rate for the transformation of kerogen to oil/gas.
So why do only ~5% of the traps contain any oil? Because that 5% is spatially located above the radial
zones of a convecting mantle.
About the Speaker:
Dr. Larry J. Robinson: So what is a metal exploration geologist doing talking to a
bunch of oil exploration geophysicists? How could he possibly help you find more
oil?
First a bit of background. Research I commenced in 1979 came to the attention of
Dr M. Glikson & Dr S. Golding, in 2000, both of whom are at the University of
Queensland. They had collaborated on a book titled, Organic Matter and
Mineralisation: Thermal Alteration, Hydrocarbon Generation and Role in
Metallogenesis, 2000, Kluwer Academic Publishers.
The Irish Club:
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