AUSTRALIA 2013Offshore Petroleum Exploration Acreage Release

RELEASE AREAS V13-1, EASTERN OTWAY BASIN, VICTORIA

Figure 1 Location of the 2013 Release Area in the Otway Basin

HIGHLIGHTS

BIDS CLOSE – 21 November 2013• Located within a gas producing region

• Access to existing infrastructure and growing energy market

• Shallow to deep water depths, 70–1030 m

• Plays include faulted anticlines and tilted fault blocks with cross-fault seal

• Multiple potential oil- and gas-prone source rocks and active petroleum systems within the region

• Special Notices apply, refer to Guidance Notes

Release Area V13-1 is located partly within the highly prospective Shipwreck Trough and extends onto the Prawn Platform in the eastern Otway Basin. The Release Area contains two exploration wells, Loch Ard 1 and Eric the Red 1.

The Otway Basin is a northwest-trending passive margin rift basin that was formed during Gondwanan break-up and the Antarctic-Australian separation. Rift-related faulting resulted in the development of large, deep depocentres, including the Voluta and Shipwreck troughs in the offshore part of the basin. The Shipwreck Trough is a structural depression between the Mussel and Prawn platforms. Deposition throughout the Late Cretaceous was dominated by deltaic sedimentation of the Sherbrook Group, which is >5000 m thick in the trough and contains most of the offshore gas discoveries. Two potential petroleum systems occur in the depocentre to the west of the Release Area; the proven Lower Cretaceous Austral 2 Petroleum System that is the source of the produced gas in the region, and the Upper Cretaceous Austral 3 Petroleum System with a potential Turonian oil-prone source rock.

AUSTRALIA 2013 Offshore Petroleum Exploration Acreage Release 1

WESTERNAUSTRALIA

NORTHERNTERRITORY

SOUTHAUSTRALIA

QUEENSLAND

NEWSOUTHWALES

VICTORIA

TASMANIA

Area V13-1Otway Basin

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Figure 2 Structural elements of the Otway Basin showing petroleum fields and discoveries, the location of regional cross-sections and the 2013 Release Area

INNER OTWAY BASIN

HunterSub-basin

TorquaySub-basin

Loch Ard 1

Eric The Red 1

Nerita 1

Wild Dog 1

VICTORIA

KingIsland

Cape Otway -

King Island HighVoluta 1

Figure 5

Triton 1Conan 1Mussel 1

Champion 1

Prawn A1

VICTORIA

TASMANIA

VICTO

RIA

Callister 1Discovery Bay 1

BridgewaterBay 1

Normanby 1

Breaksea Reef 1

Hill 1

Amrit 1

Pecten 1A

Shipw

reck Trough

Figure 4

PrawnPlatform

HunterSub-basin

NelsonSub-basin

OtwayRanges

V13-1

Henry

Thylacine

Casino

Martha

La BellaGeographe

Minerva

ButtressLangley

0 75 km

WA

NT

SA

QLD

NSWVIC

TAS

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Well symbol information is sourced either from "open file" data from titleholders where this is publicly available as at 1 December 2012 or from other public sources. Field outlines are provided by EncomGPinfo, a Pitney Bowes Software (PBS) Pty Ltd product. Whilst all care is taken in the compilation of the field outlines by PBS, no warranty is provided re the accuracy or completeness of the information, andit is the responsibility of the Customer to ensure, by independent means, that those parts of the information used by it are correct before any reliance is placed on them.

38°

40°

144°142°

Petroleum exploration well - Not classifiedPetroleum exploration well - Dry holePetroleum exploration well - Oil and gas showPetroleum exploration well - Gas showPetroleum exploration well - Gas discovery

Minor faultMajor fault

Buried Paleozoic basement high

2013 Offshore PetroleumAcreage Release Area

Gas field

Eumeralla Formation outcrop Basin outlineSub-basin outlineSeismic section figure location

Scheduled area boundary(OPGGSA 2006)

Gas pipelineGas pipeline (proposed)

Oil pipeline

AUSTRALIA 2013 Offshore Petroleum Exploration Acreage Release 3

Figure 3 Stratigraphy and hydrocarbon discoveries of the Otway Basin based on the Otway Basin Biozonation and Stratigraphy Chart 34 (Mantle et al, 2009). Geologic Time Scale after Gradstein et al (2012)

10

20

30

40

50

60

70

80

90

100

110

120

130

Berriasian

Valanginian

Hauterivian

Barremian

Aptian

Cre

tace

ous

Albian

Early

Cenomanian

Turonian

Coniacian

Santonian

Campanian

Late

Maastrichtian

Danian

Selandian

Thanetian

Ypresian

Lutetian

Bartonian

Priabonian

Eocene

Paleocene

Pale

ogen

e

Rupelian

Chattian

Oligocene

Aquitanian

Burdigalian

Langhian

Serravallian

Tortonian

MessinianZanclean

PiacenzianGelasianCalabrian

IonianTarantianHolocene

Pleistocene

Pliocene

MioceneNeo

gene

Quaternary

T4

T3

T2

T1

LC2

LC1.1

LC1

EC2

Otway Basinhorizons

(Krassay et.al, 2004)

Heytesbury

Nirranda

Wangerrip

Sherbrook

Shipwreck

Eumeralla

Crayfish

WhalersBluff

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GellibrandMarl

Lindon 1

Windermere 2

Port Fairy 1

Geographe 1

Flaxmans 1Vaughan 1

Port Campbell 4Windermere 1

Port Fairy 1Geographe North 1

Westgate 1A

Argonaut 1A

Boggy Creek 1Buttress 1Caroline 1

Casino 1Casino 2Casino 3Dunbar 1

Grumby 1Halladale 1 DW1

Henry 1 ST1Iona 1-2

La Bella 1Langley 1McIntee 1Martha 1

North PaarattePecten 1A

Penryn 1Port Campbell 1

Seamer 1Skull Creek 1

Thylacine South 1Vaughan 1

Wallaby Creek 1

Breaksea Reef 1 ST1Callista 1

Howmains 1Minerva 1-4Normanby 1Thylacine 1

Triton 1 ST1

Breaksea Reef 1 ST3

Major 1

Garvoc 1Wallaby 2

Port Campbell 4

Breaksea Reef 1Port Fairy 1

Mylor 1

Geographe 1, Thylacine 1

Casino 2, Halladale 1 DW1

Casino 1, Minerva 1-4

Flaxmans 1, Langley 1Skull Creek

Period Epoch StageAge(Ma)

Otway Basinphases

Port Campbell Embayment(including Shipwreck Trough)

FlaxmanFormation (B)

FlaxmanFormation (A)

WaarreFormation (Cb)

WaarreFormation (Ca)

WaarreFormation (B)

WaarreFormation (A)

EumerallaFormation

Otw

ay G

roup

Pretty HillFormation

CastertonFormation

Hey

tesb

ury

Gro

up

Port CampbellLimestone

Hanson Plain Sand

Newer Volcanics

CliftonFormation

NarrawaturkMarl (Upper)Wangoom

SandNarrawaturk

Marl(Lower)

MepungaFormation

Nirr

anda

Gro

up

DilwynFormation

PemberMudstone

Wan

gerri

p G

roup

Pebble PointFormation

(Upper)Pebble Point

Formation(Lower)

MassacreShale

Wiridjil Gravel

TimboonSandstone

SkullCreek

MudstoneSh

erbr

ook

Gro

up

Belfast Mudstone (C)

Belfast Mudstone (B)

BanoonMember

Hydrocarbon Shows

NullawarreGreensand

Belfast Mudstone (A)Flaxman

Formation (C)

Paar

atte

Form

ation

AUSTRALIA 2013 Offshore Petroleum Exploration Acreage Release 4

Figure 4 AGSO seismic line 137/05 across the easternmost Shipwreck Trough and Prawn Platform, Otway Basin. Location of the line is shown in Figure 2. Modified after O’Brien et al, 2006

V13-1

Top Basement

Top Mirranda Group

Top WangeripGroup

Cretaceous

Top

Top Otway Group

Top Warree Formation

Top Flaxman Formatio

nTop Belfast Mudstone

Prawn PlatformShipwreckTrough

Minerva 1 Loch Ard 1NW SE

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0D

epth

(km

)

5

4

3

2

1

Line AGSO 137/05

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Figure 5 Regional cross section across the Otway Basin showing position of the present-day peak hydrocarbon generation zone. Location of the line is shown in Figure 2. Modified after O’Brien et al, 2009

Basement

V13-1OTWAY BASIN Cape Otway -

King Island High

Current peakgeneration zone

Heytesbury Group

Nirranda Group

Wangerrip Group

Sherbrook Group

Belfast Mudstone

Turonian sections

Otway Group

Pecten 1A Minerva 1 Loch Ard 1EW

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0

2

Dep

th (k

m)

4

6

8

10

12

14

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PETROLEUM SYSTEMS ELEMENTS

Eastern Otway Basin

Sources • Aptian–Albian lower coastal plain and peat swamp Eumeralla Formation shale and coal (Austral 2)

• Upper Cretaceous–lowest Paleogene fluvio-deltaic Sherbrook Group (Turonian Waarre Formation and Coniacian–Santonian Belfast Mudstone) and marginal marine basal Wangerrip Group (Austral 3 unproven offshore)

Reservoirs • Upper Cretaceous lower delta plain and marginal marine Waarre and Flaxman formations

• Upper Cretaceous marine Thylacine Member, Belfast Mudstone

• Upper Cretaceous deltaic Paaratte Formation

• Paleocene shallow marine Pebble Point FormationChallis Formation and deltaic Nome Formation

Seals Regional seal• Upper Cretaceous Belfast Mudstone

Intraformational seals• Uppermost Cretaceous/Paleocene Massacre Shale

• Paleocene–Eocene Pember Mudstone and Dilwyn Formation

• Eocene Mepunga Formation

Traps • Faulted anticlines, tilted fault blocks with cross-fault seal

INFRASTRUCTURE AND MARKETSThe 2013 Release Area is proximal to the Geographe, Thylacine and La Bella gas fields. The eastern Otway Basin is an established gas producing province that services the southeastern Australian energy market. The greater Melbourne region currently represents Australia’s largest domestic gas market and is supported by major petroleum refineries. The City of Portland is the nearest centre along the western Victorian coast and is known for the deep water port that was established for aluminium smelting operations

CRITICAL RISKSThe key risk is migration distance and access to hydrocarbon charge from effective source kitchens within the Shipwreck Trough. Fault-seal integrity is an issue on the Prawn Platform, particularly as local structuring occurred during the Turonian. The presence of sufficiently thick intraformational and regional sealing lithologies over good quality reservoirs is also uncertain.

DATA SETSFor the Wells Data Listing go to http://www.petroleum-acreage.gov.au/2013/support/geo.html

For the Seismic Surveys Listing go to http://www.ga.gov.au/energy/projects/acreage-release-and-promotion/2013.html#data-packages

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GEOSCIENCE AUSTRALIA PRODUCTS

Regional Geology and Seismic• Geology and hydrocarbon prospectivity of the deepwater Otway and Sorell basins, offshore southeastern Australia.

Geoscience Australia Record 2013/02. GEOCAT 74603.

• Time-Depth Functions for the Otway Basin. Geoscience Australia Record 2004/02. GEOCAT 49566

• An Audit of Selected Offshore Petroleum Exploration Wells in the Otway Basin, Southeastern Australia. Geoscience Australia Record 2003/21. GEOCAT 47377

• Deep Structure of the Otway Basin, Southeastern Australia, Survey 137 (Phases 1 and 2): Post-cruise report. Australian Geological Survey Organisation Record 1995/18. GEOCAT 14810

• NGMA/PESA Otway Basin Symposium, Melbourne, 20 April 1994: Extended Abstracts. Australian Geological Survey Organisation Record 1994/14. GEOCAT 14724

• Otway Basin Cross-section, SA, Australian Geological Survey Organisation Record 1992/07. GEOCAT 14518

• Otway Basin Seismic Data, 1992. GEOCAT 20759

• Offshore Otway Basin Study, 1988. GEOCAT 20829

• Extended abstracts: Otway Basin Workshop, Canberra, 17 March 1987, Bureau of Mineral Resources Record 1987/09. GEOCAT 14137

Stratigraphy• Otway Basin Biozonation and Stratigraphy Chart 9 – Otway Basin. GEOCAT 23350

• Otway Basin Biozonation and Stratigraphy Chart 34 – Otway Basin. GEOCAT 70371

• New and Revised Palynological Data for the Otway Basin, Geoscience Australia Record 2004/22. GEOCAT 61366

• Otway Basin - Biostratigraphic Dataset, 2001. GEOCAT 37688

Petroleum Systems and Accumulations• The Oils of Eastern Australia, 2002. GEOCAT 68754

• South-eastern Australia Surface Geochemistry II: Light Hydrocarbon Geochemistry in Bottom-waters of the Gippsland Basin, Eastern Otway Basin, Torquay Sub-basin and the Durroon Sub-basin. Vols 1 and 2, Australian Geological Survey Organisation Record 1992/54. GEOCAT 14562

• Australian Petroleum Accumulations Report. Otway Basin, South Australia, Victoria and Tasmania, 1990. GEOCAT 37053

• Preliminary Post-cruise Report: Hydrocarbon Gas Geochemistry in sediments of the offshore Otway and Gippsland Basins: Project 9131.20

Contact Geoscience Australia’s Sales Centre for more information or to order these reports or products, phone 61 (0)2 6249 9966, email sales@ga.gov.au

AUSTRALIA 2013 Offshore Petroleum Exploration Acreage Release 8

KEY REFERENCESBOREHAM, C.J., HOPE, J.M., JACKSON, P., DAVENPORT, R., EARL, K.L., EDWARDS, D.S., LOGAN, G.A. AND KRASSAY, A.A., 2004—Gas–oil–source correlations in the Otway Basin, southern Australia. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds), Eastern Australasian Basins Symposium II, Petroleum Exploration Society of Australia, Special Publication, 603–627.

CLIFF, D.C.B., TYE, S.C. AND TAYLOR, R., 2004—The Thylacine and Geographe gas discoveries, offshore eastern Otway Basin. The APPEA Journal 44(1), 441–462.

GEOLOGICAL SURVEY OF VICTORIA, 1995—The stratigraphy, structure, geophysics and hydrocarbon potential of the Eastern Otway Basin. Geological Survey of Victoria, Report 103, 241 pp.

GIBSON, G.M., MORSE, M.P., IRELAND, T.R. AND NAYAK, G.K., 2011—Arc-continent collision and orogenesis in western Tasmanides: Insights from reactivated basement structures and formation of an ocean-continent transform boundary off western Tasmania. Gondwana Research, 19, 608–627.

GRADSTEIN, F.M., OGG, J.G. SCHMITZ, M.D. AND OGG, G.M. (eds), 2012—The Geologic Time Scale 2012: Volumes 1 and 2. Elsevier BV, 1144 pp.

HALL, M. and KEATLEY, J. 2009—Otway Basin, stratigraphic and tectonic framework. GeoScience Victoria 3D Victoria Report 2, Department of Primary Industries.

KRASSAY, A.A., CATHRO, D.L. AND RYAN, D.J., 2004—A regional tectonostratigraphic framework for the Otway Basin. In: Boult, P.J., Johns, D.R. and Lang, S.C. (eds), Eastern Australasian Basins Symposium II, Petroleum Exploration Society of Australia, Special Publication, 97–116.

LUXTON, C.W., HORAN, S.T., PICKAVANCE, D.L. AND DURHAM, M.S., 1995—The La Bella and Minerva gas discoveries, offshore Otway Basin. The APEA Journal, 35, 405–417.

MANTLE, D.J., BERNECKER, T., KELMAN, A.P. AND PARTRIDGE, A.D., 2009—Otway Basin, Biozonation and Stratigraphy, 2009, Chart 34. Geoscience Australia.

O’BRIEN, G.W., BERNECKER, T., THOMAS, J.H., DRISCOLL, J.P. AND RIKUS, L., 2006—An assessment of the hydrocarbon prospectivity of Areas VIC/O-06(1), VIC/O-06(2), VIC/O-06(3) and V06-1, eastern onshore and offshore Otway Basin, Victoria, Australia. Victorian Initiative for Minerals and Petroleum Report 90, Department of Primary Industries.

O’BRIEN, G.W., BOREHAM, C.J., THOMAS, H.J. AND TINGATE, P.R., 2009—Understanding the critical success factors determining prospectivity—Otway Basin, Victoria. The APPEA Journal, 49(1), 129–170.

PARTRIDGE, A.D., 2001—Revised stratigraphy of the Sherbrook Group, Otway Basin. In: Hill, K.C. and Bernecker, T. (eds), Eastern Australian Basins Symposium, A Refocused Energy Perspective for the Future, Petroleum Exploration Society of Australia, Special Publication, 455–464.