contentsCentral Australian Basins Symposium (CABS 3) July 16-17, 2012, Alice Springs
A Devonian Rimmed Carbonate Platform Complex and Barrier Reef Complex Underlies the Pedirka Basin in the Simpson DesertGreg Ambrose, Central Petroleum
Fig. 1. Location map.
Figs. 2a and b: New seismic data over the Simpson Desert within the Warburton Basin sequence.
Fig. 3. Devonian Palaeofacies.
Fig. 4. Cross-section through the Eringa and Madison troughs.An exciting new palaeozoic reef ternane will be showcased at CABS3, 16-17 July, 2012. Numerous oil/gas plays are evolving as more seismic is being acquired. Important seismic signatures suggest an active petroleum system in this previous unknown reefal terrane.
In the northern Simpson Desert within the Warburton Basin sequence, new seismic data (see Figure 2a and b) has outlined a giant Devonian barrier reef build-up of up to 1.7 km thick formed on the margin of the Hale River Block where reef facies underlie the Pedirka Basin. This is the first example of this and associated features east of the Canning Basin and their presence gives credence to earlier interpretations of a rimmed carbonate platform facies (see Figure 3) developed over the Arltunga Arch about 20 km to the south (Simpson East Prospect). There will be at least two papers delivered at CABS 3 discussing this newly discovered carbonate terrane.
Barrier reef development was controlled by interplay between gradual continued subsidence on a major tensional fault, the Pellinor Fault and eustatic sea level events which facilitated in a general sense, 'keep up aggradational sedimentation' via barrier reef development. This style of aggradational sedimentation was also pervasive during development of thick back reef and fore reef facies which are over 1.2 km thick. The reef facies have not been drilled but seismic signatures suggest channelised fore reef/slope sediments dip away from the barrier reef core at a high angle and thin basin ward into pelagics and fine clastics of the distal basin.
All the classic facies associations seen in the hydrocarbon bearing Devonian - Carboniferous sequences of North America (e.g. Leduc field) and the North Caspian Region (e.g. Tengiz field) are seen in some form or other in the Pellinor Barrier Reef Complex (Pellinor Lead) and the Arltunga Carbonate Platform Complex (Simpson East Prospect) developed to the south. Potential reservoirs in these two linked sedimentary complexes include, for the barrier reef complex: fringe reef/back reef/barrier reef/channelized fore reef slope/and toe of slope apron clastics.
The Simpson East Prospect alone, which is a carbonate platform play, includes P50 00IP of 1.4 bbl. A schematic regional east-west cross section across the Simpson Desert area is depicted in Figure 4. Reefal facies are positively identified in the east and CTP also believes they could occur on the western margin of the basin.
In the case of the carbonate platform to the south, potential reservoirs occur in: the inner platform/carbonate mound facies/platform rim/fore reef slope/and toe of slope apron clastics. All of these facies have reservoired hydrocarbons in different basins around the world.
The carbonate facies architectures in both studied complexes are controlled by salient basement faults which were largely tensional during the Devonian-Carboniferous with very large displacements of up to 2 km (e.g. Pellinor Fault).
Drape and compaction effects both over the main tectonic elements and massive biothermal reefal developments controlled structures at Permian and Mesozoic levels. Consequently some of the mapped prospects have multi-target potential in both Palaeozoic and Mesozoic sequences.
Hydrocarbon gas chimneys and associated HRDZs are associated with major fault zones controlling basinal facies down dip from Devonian platform/ reefal complexes. The charge is most likely coming from Devonian source rocks which were probably generative during the Cretaceous. This is encouraging from a charge perspective and it is well known from other drilled Devonian carbonate basins that associated facies can provide excellent oil/gas source potential (e.g. back-reef and forereef facies).
This newly discovered facies terrane will be discussed in more detail at the CABS 3 Symposium to be held in the Alice Springs Convention Centre.
In regards to CABS 3, more information regarding papers, sponsorships, the field trip etc is available from the website: www.pesa.com.au/cabs3 or contact the Chairman, Jack Mulready: email mulcon@bigpond.com, mobile 0409 006 550, phone 03 9855 9803.
For more details on the Devonian sequence, two detailed CDs are available from Greg Ambrose at Central Petroleum, phone 044 882 2136, email: gregambrose@centralpetroleum.com.au.
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An exciting new palaeozoic reef ternane will be showcased at CABS3, 16-17 July, 2012. Numerous oil/gas plays are evolving as more seismic is being acquired. Important seismic signatures suggest an active petroleum system in this previous unknown reefal terrane.
In the northern Simpson Desert within the Warburton Basin sequence, new seismic data (see Figure 2a and b) has outlined a giant Devonian barrier reef build-up of up to 1.7 km thick formed on the margin of the Hale River Block where reef facies underlie the Pedirka Basin. This is the first example of this and associated features east of the Canning Basin and their presence gives credence to earlier interpretations of a rimmed carbonate platform facies (see Figure 3) developed over the Arltunga Arch about 20 km to the south (Simpson East Prospect). There will be at least two papers delivered at CABS 3 discussing this newly discovered carbonate terrane.
Barrier reef development was controlled by interplay between gradual continued subsidence on a major tensional fault, the Pellinor Fault and eustatic sea level events which facilitated in a general sense, 'keep up aggradational sedimentation' via barrier reef development. This style of aggradational sedimentation was also pervasive during development of thick back reef and fore reef facies which are over 1.2 km thick. The reef facies have not been drilled but seismic signatures suggest channelised fore reef/slope sediments dip away from the barrier reef core at a high angle and thin basin ward into pelagics and fine clastics of the distal basin.
All the classic facies associations seen in the hydrocarbon bearing Devonian - Carboniferous sequences of North America (e.g. Leduc field) and the North Caspian Region (e.g. Tengiz field) are seen in some form or other in the Pellinor Barrier Reef Complex (Pellinor Lead) and the Arltunga Carbonate Platform Complex (Simpson East Prospect) developed to the south. Potential reservoirs in these two linked sedimentary complexes include, for the barrier reef complex: fringe reef/back reef/barrier reef/channelized fore reef slope/and toe of slope apron clastics.
The Simpson East Prospect alone, which is a carbonate platform play, includes P50 00IP of 1.4 bbl. A schematic regional east-west cross section across the Simpson Desert area is depicted in Figure 4. Reefal facies are positively identified in the east and CTP also believes they could occur on the western margin of the basin.
In the case of the carbonate platform to the south, potential reservoirs occur in: the inner platform/carbonate mound facies/platform rim/fore reef slope/and toe of slope apron clastics. All of these facies have reservoired hydrocarbons in different basins around the world.
The carbonate facies architectures in both studied complexes are controlled by salient basement faults which were largely tensional during the Devonian-Carboniferous with very large displacements of up to 2 km (e.g. Pellinor Fault).
Drape and compaction effects both over the main tectonic elements and massive biothermal reefal developments controlled structures at Permian and Mesozoic levels. Consequently some of the mapped prospects have multi-target potential in both Palaeozoic and Mesozoic sequences.
Hydrocarbon gas chimneys and associated HRDZs are associated with major fault zones controlling basinal facies down dip from Devonian platform/ reefal complexes. The charge is most likely coming from Devonian source rocks which were probably generative during the Cretaceous. This is encouraging from a charge perspective and it is well known from other drilled Devonian carbonate basins that associated facies can provide excellent oil/gas source potential (e.g. back-reef and forereef facies).
This newly discovered facies terrane will be discussed in more detail at the CABS 3 Symposium to be held in the Alice Springs Convention Centre.
In regards to CABS 3, more information regarding papers, sponsorships, the field trip etc is available from the website: www.pesa.com.au/cabs3 or contact the Chairman, Jack Mulready: email mulcon@bigpond.com, mobile 0409 006 550, phone 03 9855 9803.
For more details on the Devonian sequence, two detailed CDs are available from Greg Ambrose at Central Petroleum, phone 044 882 2136, email: gregambrose@centralpetroleum.com.au.
