Perth Basin (Western Australia)

Exoma Energy (ASX: EXE) have recently acquired from Advent Energy, 100% of EP 419 which consists of 9.5 graticular blocks or 635km2 on the north-eastern side of the Perth Basin to the east of the Eneabba Fault system.   Advent Energy have retained a 3% royalty over the title.

EP 419 and surrounding hydrocarbon fields

Independent Geologist's Summary Points

EP 419 is under-explored, having not been fully covered by seismic data nor penetrated by any petroleum wells. Nearby wells, include Erregulla-1 and 2, and West Erregulla-1, all of which intersected gas in the Permian section. Erregulla-2 also had sub-commercial oil recovery from the Jurassic Eneabba Formation. Immediately to the west of the Permit, the Eneabba-1 and Donkey Creek-1 wells penetrated a thick sequence of Jurassic and Triassic rocks, but were not drilled to the Permian section. Some fluorescence was noted in the Woodada and Kockatea Formations in these wells

Lead 1 is a large fault dependent trap located in the eastern part of EP 419 adjacent to the Urella Fault. Seismic coverage is very sparse, but the structure appears to extend over an area of more than 5km2. Further seismic would be needed to mature the lead, but OOIP could be more than 25 MMbbl, if a 10m reservoir thickness full to spill point is envisaged. The integrity of the cross fault seal is the main risk on this structure.

A smaller fault dependent trap, Lead 2 is mapped in the north-western corner of the permit. Although this lead is seen on three seismic lines the seismic quality is poor and once again additional better quality seismic is required to mature it to prospect status. Based on the current mapping the structure has an areal extent of 2km2 and could trap volumes of 15MMbbl OOIP. However this lead is high risk for cross fault seal since the fault throw is likely to exceed the known seal thickness at this location and therefore will require the fault plane itself to seal.

Although Leads 1 and 2 have no analogous commercial discovery in the Perth Basin, a sub-commercial volume of oil has been trapped in the Eneabba sands of Jurassic age in a similar fault structure tested by the Erregulla-2 well located in the adjacent permit to the north of EP 419. Reservoir presence and quality are not significant risks in this permit.

Lead 3 is a low relief Jurassic age anticlinal trap to the east of Lead 2 and is analogous to Mt Horner. On current mapping this lead has areal closure of about 1km2 and could trap more than 2 MMbbl OOIP. The seismic coverage is sparse therefore this area has potential to define more and larger structures with improved seismic quality and density.