Research Reading14 Mar 2025 14:16
To evaluate the potential success of Empyrean Energy's Wilson River-1 well in ATP 1173, Southwest Queensland, Australia, we need to consider the geological context of the target formations (Murta, Birkhead, and Hutton) within the Eromanga Basin, historical drilling outcomes, and the specifics of the well design. Below, I’ll break this down based on the geological characteristics of these formations, insights from previous exploration efforts in the region, and the operational plan outlined.
Geological Context of Target Formations:
Murta Formation (Cretaceous)
Characteristics: The Murta Formation consists of fluvio-lacustrine siltstones and sandstones with high organic matter content. It’s recognized as one of the most important source rocks in the Eromanga Basin, with studies showing low to excellent total organic carbon (TOC) content and thermal maturity at the onset of the oil window (immature to early mature). It also exhibits good hydrocarbon generation potential, with some areas showing high production indices.
Reservoir Potential: The Murta Formation includes lacustrine shoreface and turbidite sandstones that have historically acted as reservoirs. Porosity and permeability can vary, but where sands are well-developed, it has proven productive (e.g., the McKinlay Member).
Historical Success: Oil has been discovered in the Murta Formation, notably at Dullingari-North 1, and it’s a secondary target in fields like the Naccowlah Block, where near-field exploration has yielded results.
Birkhead Formation (Jurassic)
Characteristics: This formation comprises fluvio-lacustrine siltstones, carbonaceous shales, and sandstones. It’s another key source rock with good to very good hydrocarbon generation potential, though kerogen-to-bitumen conversion is generally low. Thermal maturity is also at the oil window’s onset in many areas, with vitrinite reflectance indicating suitability for oil generation in regions like the Nappamerri Trough and Southwest Queensland.
Reservoir Potential: Meandering fluvial sandstones in the Birkhead Formation serve as reservoirs, though expulsion efficiency has been low in some areas, suggesting late entry into the oil window. However, where structural traps align with mature source rocks, it has produced oil.
Historical Success: Notable discoveries include a 20-meter oil column in the Kangaroo-1 well (2016) in the Birkhead Formation, expanding prospectivity westward in the basin, and contributions to fields along the Naccowlah-Jackson Ridge.
Hutton Sandstone (Jurassic)
Characteristics: A widespread, high-energy fluvial sandstone with excellent reservoir qualities—porosities up to 25% and permeabilities up to 2500 mD. It’s less of a source rock and more of a primary reservoir, often charged by hydrocarbons migrating from the Birkhead or Murta formations.
Reservoir Potential: The Hutton Sandstone is a principal reservoir in the Cooper-Eromanga region, with braided fluvial sands