Perth, Apr 21, 2008 (ABN Newswire) - A technical paper summary by Central Petroleum Limited (Central)(ASX: CTP)(PINK: CPTLF) Manager-Geology Greg Ambrose and consultant Dr Mike Middleton has concluded that the Amadeus Basin may be more prospective than the Canning Basin, although the basins have much in common, both being examples of sparsely explored Australian frontier basins and both being examples of producing basins.

A summary follows.

The Canning Basin versus the Amadeus Basin:

A Review of Hydrocarbon Prospectivity
(A Proposed Technical Paper by Greg Ambrose and Dr Mike Middleton)

Amadeus Basin

- 170,000 km2
- Proterozoic to Devonian sediments
- 1 exploration well per 5,000 km2
- In relatively continuous production since mid 1980s
- Recoverable hydrocarbons discovered to date : 25 MMbbls oil and c.750 BCFG in the Palm Valley and Mereenie fields on original discovery at 2P level ie c. 150 MMBOE.
- All production thus far from Orodovician sandstones
- 33 exploration wells drilled, 3 discoveries, 5 technical gas discoveries which flowed gas to surface, and 13 exploration wells which were drilled off-structure
- 4.5 mmboe average per exploration well
- Of a total number of 83 reservoir intersections in 33 exploration wells, 43 reported reservoirs with oil or gas shows
- Commercial success rate is 11%
- The technical success rate is 40%
- Multi-commodity targets( oil, wet gas, methane and Helium).
- First well drilled 1962, Ooraminna 1 which was a technical success flowing gas to surface, one exploration well drilled in the last 15 years
- .Exploration technology (particularly seismic) dates back to the 1960s and until Central Petroleum's efforts in 2007 and 2008, the basin was a generation behind modern exploration methodologies. Tight 2D seismic grids are generally absent and there are no 3D grids in the basin
- Exploration finding costs are low at between US$0.5-1.3 per BOE
- Assuming a success rate of 11% for existing leads and prospects, then the historically risked "yet-to-find" reserves stand at 634 mmbl BOE or 3.9 TCF of gas-NTGS 2005.
- Five petroleum systems are recognized in the basin to date
- Existing data suggests all fields in the Amadeus will be filled to spill
- There does not appear to be Tertiary reactivation of the Alice Springs Orogeny structural fabric which favours retention of hydrocarbon deposits
- Complex structural history, stratigraphy and petroleum geology has produced a plethora of play types, prospects and leads even with areally very limited seismic coverage to date-c.8,000 line km. (0.05 line km per km2 of area)
- The Amadeus Basin sequences show marked variations in magnetic susceptibility enabling detailed structural signatures to be generated from First Derivative aeromagnetics data
- Halotectonics (salt structures) likely to be important in future exploration.


Canning Basin

- 530,000 km2 onshore and 640,000 km2 (including offshore)
- Ordovician to Cretaceous
- 1 exploration well per 2,000 km2
- In production since mid 1980s
- Recoverable hydrocarbons discovered to date : 2.8 mmbbls oil at 2P level on discovery in 5 fields including Blina, Sundown et al, 6 other small discoveries some of which have produced
- Most production thus far from Devonian limestones
- 264 exploration wells drilled
- Commercial success rate 2%
- 0.015 mmbbls average discovery rate per exploration well (c.15,000 bbls)
- Both oil and gas targets
- Recently drilled 2007, 2008 in addition to historical wells
- First drilled 1922, first technical success was the oil discovery well Pictor 1 - 1984
- Technology used dates back to the 1920s, but sporadic exploration since then has utilised modern seismic and drilling methods
- 3-4 petroleum systems recognised in the basin to date
- Existing data suggests that all structures may not be filled to spill
- Structurally complex with a plethora of play types, areally limited seismic to date c. 80,000 line km. (0.125 line km per km2 of area)
- Magnetic susceptibility mapping and First Vertical Derivative analyses are useful but do not appear to be as useful in the Canning in comparison to the Amadeus
- Halotectonics (salt structures) likely to be important in future exploration

Conclusions

The Canning Basin is 3 times the size of the Amadeus Basin but has nearly :
1) 8 times the number of wells
2) A drill hole density nearly 3 times higher
3) nearly 10 times the amount of seismic
4) A seismic density nearly 3 times higher

These statistics indicate the Canning has undergone relatively more intense exploration than the Amadeus Basin but significantly the following statistics suggest the Amadeus may be more prospective.

The Amadeus Basin has:
1) A commercial success rate 5 times higher
2) Discovered Recoverable hydrocarbons (2P) fifty times higher
3) A discovery rate BOE per well three hundred times higher
4) Nearly double the number of petroleum systems


Note: These conclusions are preliminary and may be qualified to an extent in a planned formal technical paper by the authors.

Greg Ambrose and Dr Mike Middleton
Perth 18th April 2008

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