“We use surface geochemistry as a screening process,” Rawson executive chairman John Conolly told EnergyReview.net.
“We are looking for big anomalies – two to ten times background readings.”
Conolly is a former professor of geology at Louisiana State University and the University of South Carolina, and was managing director of Sydney Oil, which was taken over by Command in 1988.
He soil gas surveys were undervalued by the petroleum industry.
“The industry has seen many inconclusive and meaningless results and has generalised on the basis of that,” he said.
“But it is very useful in basin fringes and areas where there are discrete oil fields. It is a rapid reconnassaince system with repeatable results."
While Rawson is using the Petrofocus soil sampling system to high-grade seismic leads in PEL107, Conolly has also used soil sampling before running seismic.
"In the 1980s Sydney Oil used geochem on the eastern side of the Cooper-Eromanga Basin in Queensland," he said.
"We found some interesting readings south-east of Nockatunga, then we ran seismic. Then we drilled and found the Maxwell oil field."
In PEL107, before the geochemical survey began there were several leads in the block identified by old Santos seismic.
The object of the survey was to high-grade these prospects so Rawson and its partners could select a target for drilling in the first half of 2006.
Rawson took 637 soil gas samples over seven days in late October and initial results showed anomalous readings over a previously mapped structure.
"We had readings that were two or three times background levels," Conolly said.
"It helped us decide what bumps we wanted to drill."
Rawson has farmed into a section of PEL107 known as the Appadare Farm-in Block.
Under the farm-in agreement, Rawson (RAW) has the right to earn a 50% interest in any hydrocarbon pool discovered by an exploration well by paying the drilling cost of that well. The existing holders of the permit are Beach Petroleum (BPT) operator and 40%, and Great Artesian Oil and Gas Limited (GOG) 60%.
