cooper history and res...

Hello all
I hope Squidgly comments as I enjoy his informed Geo comments to us Layman re reserves and where the oil potentially comes from.
Just a cut and paste but heaps of sites re potential of
STRATIPGRAHIC PLAYS.
EROMANGA BASIN
Reports
The petroleum geology of South Australia, Volume 2: Eromanga Basin. 2nd edn. (Cotton, T.B.,
Scardigno, M.F. and Hibburt, 2006)
Publications
Acreage releases, previous
Summary
Age Early Jurassic Late Cretaceous.
Area in South Australia 360 000 km2 (139 000 sq. miles).
Depth to target zones 12003000 m.
Thickness Up to 3000 m.
Hydrocarbon shows Commercial discoveries of oil from almost every unit from the
Poolowanna to the base Cadna-owie Formation in the Cooper
region; elsewhere shows in the Poolowanna Formation.
First commercial discovery 1976 gas (Namur 1), 1978 oil (Strzelecki 3).
Identified reserves Cooper region only; elsewhere nil.
Undiscovered resources (50% prob.) 2.4 x 106 kL (15.1 mmbbl); western Eromanga Basin
8.4 x 106 kL (52.8 mmbbl) (PIRSA estimate June 1996).
Production Cooper region only refer to Cooper Basin chapter; elsewhere
nil.
Basin type Intracratonic.
Depositional setting Productive non-marine sequence overlain by non-productive
marine, marginal marine and non-marine sediments.
Reservoirs Braided and meandering fluvial, shoreface and lacustrine
turbidite sandstones.
Regional structure Broad, four-way dip closed anticlinal trends in regional sag
basin.
Seals Lacustrinefloodplain shales and basin-wide volcanogenic
sandstones.
Source rocks Underlying Cooper Basin coal and siltstone; Birkhead and Murta
formations siltstone and coal.
Depth to oil/gas window 1250 m (oil).
Number of wells ~1800 in Cooper region; ~30 elsewhere.
Seismic line km 104 021 2D; 8642 3D km2
Since 1959 over 1400 wells have penetrated the Eromanga Basin sequence and over 100 000 km of seismic
has been acquired (Fig. 1). Exploration has concentrated in the Cooper region. A new phase of exploration
for oil in the Eromanga Basin commenced in 2002 in the 27 new licences resulting from the expiry of PELs 5
and 6 in 1999. Most new entrant explorers are currently targeting Eromanga Basin oil plays.
Undiscovered resources
As the Eromanga Basin is clearly oil-prone, only undiscovered oil resources are calculated, however gas
discoveries are known from the Cooper region. The gas in these fields has been sourced from the underlying
Permo-Carboniferous Cooper Basin. In the western Eromanga Basin, gas discoveries are possible,
particularly in areas overlying the older infrabasins (Pedirka and Simpson basins), but it is unlikely that small
gas discoveries in this area would be economic.
Petroleum exploration in the Eromanga Basin in South Australia has traditionally concentrated in the portion
underlain by the highly productive Cooper Basin, a relatively mature area. In addition, there is the likelihood
that a significant amount of the oil found in this area has been sourced from the underlying Cooper Basin.
For these reasons, undiscovered oil resources in this area are best estimated using methods that extrapolate
discovery trends. Areas to the west have had minimal exploration effort, with only one sub-economic discovery. Oil found here
will probably be sourced from the Poolowanna and Birkhead formations or the underlying Pedirka and
Simpson basins. Estimates of undiscovered resources in the western Eromanga are best carried out by a
method that uses available geological data and Monte Carlo type statistical techniques to calculate, as a
probability distribution, the undiscovered resources for each play. Western Eromanga Basin
For a commercial petroleum field to exist in the western Eromanga Basin, four essential components are
required: a mature source, a reservoir horizon, a seal horizon and a structure over the reservoir horizon
that will concentrate the petroleum in economic quantities and that was present at the time of the petroleum
expulsion from the source rock. Usually this is an anticline, but stratigraphic traps can also be important.
When all four of these occur together, a petroleum play or a potential target for exploration exists.