Ann: South Erregulla Update, page-125

The Bit Basher Shale seems to work very effective to separate the two accumulations in the Kingia and in the HC:

From the WE2 Completion Report:

"The top of the Kingia Sandstone porosity was intersected at 4792 m and marked by a sudden increase in total gas, from a background of 15 units, to a sustained gas show exceeding 200 units over 46 metres, peaking at 325 units (C1 47996ppm, C2 556ppm, C3 59ppm, C4 28ppm & C5 18ppm) at 4814 m.

Passing into the Bit Basher Shale caused the total gas to drop back to a background of 3-10 units.

The background gas level remained low at 3 units until reaching permeable sandstone in the High Cliff Sandstone at 4928 m, when Total Gas increased by a multiple of 128 to 384 units (C1 61680ppm, C2 214ppm, C3 18ppm, C4 0ppm & C5 0ppm). This gas show originated by a drilling break of 17 m/h over a background of 1.5 m/h.

Also indicated in the schematic logs within the grey BB section in the stratigraphic section comparation published at GOC in 2019:



Here the MDT pressure summary from the well completion report. It covers only 20m within the Kingia - HC was encountered at 4,928 MD:



The completion report clearly says:


Kingia Sandstone

The Kingia formation is sometimes referred to as a sub-unit of the High Cliff formation in external references. However, at the West Erregulla field (located deeper in the Dandaragan Trough), the Kingia formation is separated from the High Cliff via a thick section of the Bit Basher Shale deposited between the two units. The Bit Basher shale is characterised by a high GR signature, a mixture of fine loose grain aggregates and black to greyish-black carbonaceous siltstone. Towards the edge of the trough, Waitsia 1 and Senecio 1 encountered approximately 40 m of gross Kingia Sandstone interval. In comparison, West Erregulla 2 penetrated 97 m of gross Kingia interval.
Above the Bit Basher Shale, the Kingia Sandstone at the West Erregulla Field can be further divided into two distinguishable sub units – the Kingia Basal Sandstone and the Kingia Marine Transition. The Irwin River Coal Measures is deposited above the Kingia Marine Transition zone and is the main source rock for both the Kingia and High Cliff formations.