IN WESTERN AUSTRALIA - Department of Mines and Petroleum

More documents

Recommendations

Info

28 PWA April Edition - State Acreage Release Richard Bruce Exploration Geologist, Resources Branch State Acreage Release March 2004 Figure 1. Location of Northern Carnarvon Basin release areas (in blue). In March 2004 the Western Australian Department of Industry and Resources released six petroleum exploration areas at the APPEA Conference and Exhibition, in Canberra. The Acreage Applications are invited for the grant of Exploration Permits for areas as in the table below. The location of the application areas is shown in figures 1, 2 and 3. Key Dates Release date: Tuesday 30 March 2004 Closing date: 4pm Thursday 30 September 2004 Release package The CD package includes non-geotechnical information such as investment background, applying for acreage and land access. Northern Carnarvon Basin Acreage The Northern Carnarvon Basin, and particularly the Barrow and Dampier Sub-basins, is one of the more intensively explored areas of Australia. Islands (such as Barrow, Airlie, Varanus and Thevenard) provide excellent locations for production facilities and bases (Fig. 1). Area L04-1 is situated some 10 km to the east of the Varanus Production Area and less than 25 km southwest from the Stag (oil) Production Licence. Combined Areas L04-2 and T04-1 lie to the west of
and immediately adjacent to the Airlie Island Production Facility, as well as immediately north of the Thevenard Production Facility. Area L04-3 is situated immediately adjacent to this facility. Water depths are less than 50 m in the release areas making jackup drilling rigs practical to use in these areas. There is a good coverage of 2D seismic and partial coverage of 3D seismic in the release areas. The offshore Northern Carnarvon Basin is Australia’s leading producer of both liquid hydrocarbons and gas. To date, most oil production has come from the Barrow Sub-basin. Key factors leading to this success include good Mesozoic source rocks, which have generated over a long period of time; Lower Cretaceous reservoir rocks with excellent porosity and permeability; and a thick and effective regional seal (Muderong Shale; Baillie and Jacobson, 1997). Most of the oilfields discovered in the Barrow Subbasin rely on fault closure where the Winning Group shales (Muderong Shale and Gearle Siltstone) provide a seal for accumulations in the Barrow Group, Windalia Sandstone Member and Birdrong Sandstone (West Australian Petroleum Ltd, 1995). Perth Basin Acreage The two Perth Basin release areas (L04-4 and L04- 5) are situated east and southeast of the Woodada gasfield respectively, in the northern part of the basin (Fig. 2). The area is readily accessible, consisting of undulating farm and shrub lands. Access from main roads is relatively simple, and petroleum-industry infrastructure includes two major gas pipelines and good roads to an oil refinery 30 km south of Perth. The logistics and economics of potential oil and gas discoveries are very positive given the proximity of existing infrastructure and an expanding market, particularly since the deregulation of Western Australian gas markets in 1988. Twelve commercial hydrocarbon fields and numerous additional significant discoveries have been made in the onshore northern Perth Basin. The largest of these by far is the Dongara field, with 14.3 Gm 3 (508 Bcf) of original in-place gas and 16.6 GL (104 million barrels) of original in-place oil. Other notable discoveries are the Woodada gasfield, the Mount Horner oilfield and the Beharra Springs gasfield. In recent years, exploration in the Perth Basin has been revitalised by the discovery of the Hovea oilfield by ARC Energy, the Beharra Springs North gasfield and the Jingemia oilfield by Origin Energy, and the offshore Cliff Head oilfield by Roc Oil. Petroleum-system analysis indicates that mature source rocks are widespread, reservoirs are abundant, and structures are well timed for hydrocarbon entrapment. A critical factor is considered to be the seal, due to the intense faulting and high sand-to-shale ratio of the post- Lower Triassic succession. The main source for oil is a basal marine facies in the Lower Triassic Kockatea Shale, with reservoirs in Lower Triassic and Permian sandstones. The main source for gas is the Permian Irwin River Coal Measures, with reservoirs in the Upper Permian and Jurassic strata. Carbonaceous horizons within the Cattamarra Coal Measures may also contribute gas from the central part of the Dandaragan Trough where the unit is up to 6000 m deep. Major play types include Permian–Triassic and Jurassic anticlines as well as Permian–Triassic tilted fault blocks and stratigraphic traps. There are many untested hydrocarbon prospects in the Perth Basin. Structures on the upthrown side of the Eneabba Fault are considered the most prospective untested plays in the release areas, especially where a reservoir is juxtaposed against sealing units such as the Cadda Formation and shale in the Cattamarra Coal Measures and Eneabba Formation. Strong PWA April Edition - State Acreage Release 29 Tectonic element Application area 5’ x 5’ Approximate graticular blocks square kilometres Northern Carnarvon L04-1 9 720 Basin (offshore) L04-2* & T04-1* 3 & 4 240 L04-3 1 80 Perth Basin (onshore) L04-4 13 1040 L04-5 15 1200 Officer Basin (onshore) L04-6 297 23760 * Combined areas flows of wet gas were encountered within fractured zones of the Kockatea Shale in Eneabba 1 in a similar structural position (Crostella, 1995), suggesting that the top Permian level could be an attractive target where sufficiently shallow. Other plays include fault plays on the eastern margin of L04-4 with a deeply buried Kockatea Shale source, and stratigraphic pinchouts within the Cattamarra Coal Measures on the western flank of the Dandaragan Trough with an intra-formational source. Officer Basin Acreage The frontier Officer Area L04-6 is being released at the request of industry who consider it has some potential for oil. The basin is under-explored probably because of its age and its remoteness. Figure 2. Location of Perth Basin release areas (in blue).
Page 1: APRIL 2004 PETROLEUM IN WESTERN AUS
Page 4 and 5: 2 PWA April Edition - International
Page 6 and 7: 4 PWA April Edition - Minister’s
Page 8 and 9: 6 PWA April Edition - Director’s
Page 10 and 11: 8 PWA April Edition - 2003 Review s
Page 12 and 13: 10 PWA April Edition - 2003 Review
Page 14 and 15: 12 In 2002, a major remote sensing
Page 16 and 17: 14 Two wildcat wells in WA-286-P (M
Page 18 and 19: 16 bearing. No significant hydrocar
Page 20 and 21: 18 The oil is a good quality 49.2°
Page 22 and 23: 20 PWA April Edition - 2003 Review
Page 24 and 25: 22 PWA April Edition - Resources Br
Page 26 and 27: 24 PWA April Edition - Magnetotellu
Page 28 and 29: 26 PWA April Edition - Magnetotellu
Page 32: 30 PWA April Edition - State Acreag
Page 35 and 36: the contractors they select have th
Page 37 and 38: y introducing appropriate organisms
Page 39 and 40: International Risk Consultancy It w
Page 41 and 42: Table 1. Reserves as at 31 December
Page 43 and 44: Gingin 0 48,545 3,169 Gipsy 315,750
Page 45 and 46: KEY: Classification 2D: 2D Reflecti
Page 47 and 48: PWA April Edition - Petroleum Wells
Page 49 and 50: Wandoo Petroleum Pty Ltd * Apache N
Page 51 and 52: PETROLEUM (SUBMERGED LANDS) ACT, 19
Page 53 and 54: WA-15-R Active H 11 19 Apr 2006 Tex
Page 55 and 56: * ChevronTexaco Australia Pty Ltd T
Page 57 and 58: Norwest Energy NL Roc Oil (WA) Pty
Page 59: EXECUTIVE Director General Jim Lime

IN WESTERN AUSTRALIA - Department of Mines and Petroleum

Create successful ePaper yourself

Delete template?

Save as template?