Oil is a liquid hydrocarbon formed deep underground from the decomposition of sea organisms such as plankton and algae. Over millions of years, heat and pressure from the changing geology transform this organic matter into oil and gas. The most common name for this is crude oil.
The Santos oil story began in earnest when in 1978 the Cooper Basin well named Strzelecki-3 recorded the biggest onshore oil flow rate in Australian history. Light gravity oil spurted from the hole at a rate of 2,400 barrels per day – easily surpassing the previous best flow from the Cooper Basin of 1,500 barrels per day from the Tirrawarra-2. On the heels of Strzelecki-3 came Dullingari-4, then Dullingari North-1 which spudded in August 1979.