ASX ANNOUNCEMENT RELEASED to the ASX DATE: 230608 TO: Manager, Company Announcements ASX Limited CONTACT: John Heugh +61 8 9474 1444 Technical Note 230608 - the Bevidere and Perceval Stratigraphic Leads

Central Petroleum Limited (Central-CTP) is focused initially on drilling conventional 4 way dip closures as oil targets in the Pedirka Basin as well as Coal Bed Methane unconventional targets but two new stratigraphic plays described in the Jurassic Poolowanna Formation and the Permian Tirrawarra Formation have combined Undiscovered Oil Initially in Place at “high” estimate potential (UOIIP) of up to 480 Mmbbls. The new play types may have additional in-situ potential in other sand bodies as well as positive regional implications. The conclusions reached in the Technical Note are :

• The Perceval and Bedivere Leads are large, with potential for 306 and 172 MMbbls UOIIP respectively. As more seismic is acquired, similar leads/prospects may evolve around other ancestral topographic highs in Central’s Pedirka permits. However, the immediate priorities are 4 way dip closure prospects such as Blamore (71 MMbbls UOIIP), Simpson West & East (240 MMbbls UOIIP), Avalon (50 MMbbls UOIIP), Bejah (125 Mmbbls UOIIP), Dune West and East (233 Mmbbls UOIIP) and, subject to further seismic interpretation, Guinevere, Vivienne and Madigan.

• The target depth for both the Perceval and Bevidere leads is relatively shallow at less than 1500m for Perceval and less than 1200 m for Bedivere.

• The top Poolowanna Cycle-1 shales and Purni shales interpreted as sealing horizons

here, are proven source rocks with a higher ratio of oil forming macerals than equivalents in the Cooper Basin (Exinite/Vitrinite 17 in the Pedirka versus 7 in the Cooper-Middleton 2003 and Smythe 1979) and may provide intra-formational seal over a wide area in the Pedirka Basin.

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• These stratigraphic plays rely upon parameters derived during deposition and hence

the traps predate oil migration making the plays less risky and thus attractive targets.

• Poolowanna Formation shales and Purni Fm shales are in the peak oil window in the Madigan Trough and are marginally mature less than 15 km from both leads.

• The potential large scale of onlap plays on the margins of ancestral topographic highs

such as the McDills Trend enhances the play application potential. While acknowledging the plays are relatively high risk, the complete absence of oil shows along the crest of the McDills Trend (Etingimbra 1 and McDills 1) could well be a function of such down flank stratigraphic traps cutting off migration to the crest of the structure.

John Heugh, Managing Director, Central Petroleum Limited

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Stratigraphic Onlap Plays Enhance The Prospectivity of the Tirrawarra Sandstone and Poolowanna Formation in the Pedirka Basin.

(CTP Technical Note 230608)

Introduction Two new stratigraphic plays centred on sedimentary onlap of Tirrawarra Sandstone and Poolowanna Formation Cycle-1 reservoirs onto the McDills High (ie Bedivere and Perceval leads) enhance the prospectivity of these formations near the McDill’s High. This may have regional implications for similar play types. Preliminary seismic mapping of the leads, which will require additional seismic to mature to drillable status, indicates an Undiscovered Oil Initially In Place at “high” estimate (UOIIP) potential of 172 MMbbls (Tirrawarra level) and 306 MMbbls (Poolowanna level Cycle-1). Target depths of 700 m -1500 m for these leads make them an attractive exploration play.

Regional Tectonic Elements in the Pedirka Basin Exploration in the Simpson Desert area is coming alive again for the first time since the 1980s with the first drilling of conventional oil targets in 15 years timed to commence in June 2008 with the exploration wells Blamore-1 and Simpson-1 and 3 CBM wells planned by Central in a back to back Pedirka campaign. The oil plays are simple structural 4-way dip closures and the early Jurassic Poolowanna Formation is a prime target in addition to Algebuckina Sandstone and early Permian Tirrawarra Sandstone targets. The Permian, Triassic and Jurassic sequences are all potentially prospective for hydrocarbons sourced from intra-formational shales which are in the peak oil window in the Madigan Trough with additional potential from in-situ generation from more marginally mature source rocks.. The Blamore-1 and Simpson-1 structures are favoured because their structural history allows entrapment at the postulated time of peak oil migration in the Cretaceous (pre-Tertiary). In

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addition the traps are unbreached by Miocene (mid-late Tertiary) faulting which is thought to explain at least some early exploration failures in the Pedirka. Hydrocarbon leakage during Miocene tectonism (faulting) of earlier formed structures charged during the Cretaceous can be readily interpreted in the Colson structure drilled in 1978 for example. Another example may be the Poolowanna Oil Pool in South Australia drilled initially in 1977 to test oil which was generated largely from Poolowanna source rocks during the Cretaceous. The pool clearly has suffered fault breach during Miocene structural rejuvenation (Ambrose et al., 2007). Favoured traps are thus those 4-way dip closures thought to be unbreached by Miocene faulting and a number of these are ready to drill while others await seismic detailing. Stratigraphic plays however, are also attractive in that their development precedes oil migration and they exhibit as a class, and specifically, relatively large potential volumes of oil-in-place. There is also a much lower risk of fault breach with these plays especially where they are not reliant on fault seal. Two examples described below rely on 3 way dip closure and sedimentary onlap onto the margins of the McDills High. The plays are controlled by two crestal wells (McDills 1 and Etingimbra 1) on the high plus zero edges defined on the existing sparse seismic grid. A previous Technical Note (250108), described the possibility of a c.950 km2 closure formed by the Camelot Fault cross cutting the Hallows Trend as a reason for the failure of McDills 1 and Etingimbra 1.The Bevidere and Perceval plays may provide an alternative or a supplementary reason for these failures via the trapping of updip migration of oil from east to west into the McDills and Etingimbra structures located at the crest of the McDill’s High.

Onlap of Permian and Jurassic Stratigraphy Onto the McDills High - other sands in addition to the Poolowanna Cycle 1 and Tirrawarra may hold similar potential in the Jurassic/Permian

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The source potential of the Poolowanna shales has been confirmed by geochemical analysis of oils and source rocks from the Poolowanna 1, Oolarinna 1 and Cuttapirrie 1 oil discoveries, while the source potential of various elements of the Permian, particularly the Permian Purni Fomation has been evaluated by Glen Joyce 1, Oolarinna 1, Colson 1 and Hale River 1. Permian TOCs average 35% and S1+S2 values average 79.6 kg/tonne.

Regional Map Showing Bedivere and Perceval Leads

The Early Jurassic Poolowanna Formation (Cycle-1) Onlap Play (Perceval Lead) The Poolowanna Formation is split into two transgressive, upward-fining cycles related to transgressive sea level events in the far northeast of the Eromanga Basin (Ambrose et al 2002, 2007). The basal unit, Cycle-1, comprises a basal, sheet-like braided fluvial sandstone 20-30m thick which grades to floodplain/crevasse splay and distributary mouthbar sandstones about 70 m thick. Lacustrine carbonaceous shales and shaly coals cap the cycle and provide source and seal. Matchup of oil and source rock geochemical characteristics has been confirmed in the Poolowanna-1 and Cuttapirrie-1 oil pools. The topset sealing shales in Cycle-1 can be correlated from Colson-1 to Poolowanna-1 and south to Cuttapirrie -1 in South Australia and appear to provide regional seal. This seal onlaps the eastern margin of the McDills High and a structural embayment can be mapped in this area providing 3 way dip closure into the zero edge. Proposed trap parameters (based on preliminary mapping and data from sparse offset wells) and Undiscovered Oil Initially In Place at “high” estimate (UOIIP) are discussed below.

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Stratigraphy in the Pedirka Basin in the area of the Simpson Desert

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The Perceval Lead

Regional Correlations Pedirka Basin – Cooper Basin

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Sedimentary Cycles in the Poolowanna Formation from Poolowanna-1 Perceval Lead Area of Closure: 16300 acres Gross Sand Thickness : 60 ft Net /Gross : 0.8 Porosity : 0.14 Height of closure : 90 msec ( 350 ft) Hydrocarbon Saturation : 0.80 1/Bo : 0.90 Geometric Factor : 0.50 Conversion Factor : 7,758 Bbls/acre.ft UOIIP = 306 MMBbl ( Note that incremental seismic is required to mature this lead to drillable prospect status).

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Current interpretations of seismic indicate a depth to the top of the Poolowanna Formation target of some 1,200-1,500m below ground level. The Poolowanna Formation onlap play (Cycle-1) is also present on the Andado Shelf to the west but additional seismic is required to define the zero depositional edge. Additional ancestral topographic highs in EP 93, EP(A)’s 130,131 and PELA 77 will provide important structural / stratigraphic targets as Central’s exploration programs in these areas evolve over time. The Early Permian Tirrawarra Sandstone Onlap Play (Bedivere Lead)

The Bedivere Lead

In the area of the Pedirka Basin the Tirrawarra Sandstone/Purni Formation reservoir-source/seal couplet is prospective on a regional basis and is a primary target in 4-way dip closures. The sequence is stratigraphically equivalent to the highly productive Tirrawarra/Patchawarra petroleum system in the Cooper Basin. In the Pedirka Basin both the Purni Formation and the Tirrawarra Sandstone onlap ancestral topographic highs such as the Mc Dills High and the Hale River High. In this case the Tirrawarra onlaps the McDills High providing an attractive oil play down flank of this “bald” high confirmed by drill holes Etigimbra-1 and McDills -1. Proposed trap parameters (based on preliminary mapping and data from sparse offset wells) and Undiscovered Oil Initially In Place at “high” estimate (UOIIP) are discussed below.

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Bedivere Lead Potential Areal Closure 21500 acres Porosity 0.12 Hydrocarbon Sat. 0.80 1/B0 0.90 Geometric Factor 0.50 Gross Thickness 30 ft Net/ Gross 0.8 Conversion factor 7758 Bbls/acre ft UOIIP = 172 MMbbl (Note that incremental seismic is required to mature this lead to drillable prospect status).

Conclusions

• The Perceval and Bedivere Leads are large, with potential for 306 and 172 MMbbls UOIIP respectively. As more seismic is acquired, similar leads/prospects may evolve around ancestral topographic highs in Central’s Pedirka permits. However, the immediate priorities are 4 way dip closure prospects such as Blamore (71 MMbbls UOIIP), Simpson West & East (240 MMbbls UOIIP), Avalon (50 MMbbls UOIIP), Bejah (125 Mmbbls UOIIP), Dune West and East (233 Mmbbls UOIIP) and, subject to further seismic interpretation, Guinevere, Vivienne and Madigan.

• The target depth for both the Perceval and Bevidere leads is relatively shallow at

less than 1500m for Perceval and less than 1200 m for Bedivere.

• The top Poolowanna Cycle-1 shales and Purni shales interpreted as sealing horizons here, are proven source rocks with a higher ratio of oil forming macerals than equivalents in the Cooper Basin (Exinite/Vitrinite 17 in the Pedirka versus 7 in the Cooper-Middleton 2003 and Smythe 1979) and may provide intra-formational seal over a wide area in the Pedirka Basin.

• These stratigraphic plays rely upon parameters derived during deposition and

hence the traps predate oil migration making the plays less risky and attractive targets.

• Poolowanna Formation shales and Purni Formation shales are in the peak oil

window in the Madigan Trough and are marginally mature less than 15 km from both leads.

• The potential large scale of these onlap plays on the margins of ancestral

topographic highs such as the McDills Trend enhances the play application potential. While acknowledging the plays are relatively high risk, the complete absence of oil shows along the crest of the McDills Trend (Etingimbra 1 and McDills 1) could well be a function of down flank stratigraphic traps cutting off migration to the crest of the structure.

Greg Ambrose John Heugh Manager-Geology Managing Director

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