BAS Chart, page-238

Whilst this is true, if you actually read the full report there's detail about the high uncertainty in the 2D seismics used (1970's technology) to try and map the subterranean geology. This is technology from 50yrs ago and it's no surprise that finding deposits was more hit and miss.
There's no detail on how deep or anything that may offer additional value to the first drilling.
Since then we have Santos immediately adjacent, in the same geologic formation, announcing success but light on details......this says much to me.