C O U NT R Y R E V IE W on troubled OIL waters Oil exploration in Australia has been fraught with disappointments in a relentless land, but onshore basins such as the Cooper Basin can still yield surprises. Just to give you an impression of the size of the Australian continent. The North Sea is outlined in red. View across the Flax-Juniper oilfield on Innamincka Petroleum lease PEL103 in the Cooper Basin looking toward Flax East-1, which © Innamincka used Petroleum, with permission proved significant upside remains in 2007. 16 GEO ExPro December 2007 Susan Turner "If we find oil, I'll wear (not eat) that hat” Coorong, Carnarvon and Cooper claimed 'experts'. Why is it that oil seems to occur in Gloomy doomsayers were the norm. Oil desolate or difficult places? In the UN Inter- in commercial quantities continued to be national Year of Planet Earth (www.yearof- a rare commodity through to the mid-20th planetearth.org) this is still a hard question century — the only serious shows came because most places are desolate. Australia in the 1920’s from east Gippsland, Victoria. is no exception and oil exploration is a Then on December 4th 1953, WAPET (West story of struggle in 'Outback' places. Australian Petroleum, a joint AMPOL, Aus- The first drilling for oil in 1881 occurred tralian Motorists Petrol Company Limited, far south in Australia on the Coorong, and Caltex venture), drilling the Rough an extensive lagoon on the embayment Range Cretaceous anticline in extreme southeast of Adelaide. Sadly, the attempt Western Australia, struck the first heavy oil. was based on mistaken identity of surface But flow rates were too low - two years and oily bitumen. They gave up at 200 m when it was over. they hit salt-water. For the next 80 years it was doubted that oil could be found in the southern “Australia is too old continent. Some even argued that “them foreign companies had come in, found oil for oil and then hidden it”! Myths were pricked by a few astute men, geologists who under- Geologists at the young national survey, stood the land and learnt from experience the Bureau of Mineral Resources (BMR), abroad. As one put it, “If we could strike had – in fact – recognised classic oilfield- commercial reservoirs of oil in our country type anticlines there in the 1930s. They it would be the biggest thing that has were spot on - all it took was time, money happened to Australia since Macarthur and 'hard yakka'. brought in the merino sheep.” These days, the Australian petroleum industry is substantial, a vibrant, growing “Its rocks are all wrong part of the economy generating over A$10 billion a year in oil and gas production and Oil in commercial quantities continued contributing billions in taxes and royalties. to be a rare commodity throughout the first Over 15,000 are directly employed and half of the century. It was Walter George more than 30,000 work in support compa- Woolnough, Commonwealth geological nies. Resources boom is the catchword. advisor, who realised that more money The current federal program is focussed and brains were needed in the search on encouraging offshore exploration for oil. After visiting North American and whereas the States have jurisdiction over Argentinian oilfields in 1930, he encour- onshore upstream activity. Over 95% per- aged the use of aerial surveys and photos, cent of Australian hydrocarbon resources and promoted commercial oil potential in (96% of the oil, and 98% of the gas) lie off- Australia and New Guinea. shore but onshore basins also clearly have t more to come. The Cooper Basin, one of the most prolific onshore hydrocarbon provinces in Australia, straddling the South Australia-Queensland border. © Innamincka used Petroleum, with permission GEO ExPro December 2007 17 C O U NT R Y R E V IE W Post-WWII bonanza 200 million years of weathering since Following a change of government the Permian have and an end to petrol rationing in 1949, created the hard the search began in earnest. Government 'gibber' peneplain surface in the advice pointed W. G. Walkley of Ampol central Australian at the best prospect in the sedimentary deserts littered with Carnarvon Basin in Western Australia, the clay and ironstone Rough Range with dome-like structures. concretions. In the early 1950’s Walkley brought over Frank Morgan, vice-president of Richfield Corporation of Texas, a top exploration geologist. Chartering an Avro Anson they flew north to Carnarvon, where the Ameri- can got to experience outback hospitality: up at 4.30 for an early take-off there was no water on tap, nobody on duty, and to wash they shared drinking water left in a creme Photo: Susan Turner de menthe bottle that did duty as a carafe. Up in the bright blue subtropical sky flying over salt pans and sand ridges area. Eventually the parent company was fact that the world’s most prolific oilfields approaching Exmouth Gulf they could see persuaded too and they built roads into were located in harsh desert. So why not the ranges rising to 300 m and extending untracked country. Rough Range 1, the in Australia’s great internal deserts? This for 100 km. Flying low, looking down on discovery well was drilled from September hard-baked 'gibber' desert country can eroded limestone canyons, the structure 1953 to May 1955. glow like a rose and has yielded surprise appeared to dip in all directions; Morgan and serendipity. stared down with his expert's eyes and sud- A Big Australian denly said, “That's textbook oil structure! If Hitting the headlines when oil was The Cooper Basin delivers we had it in the States we'd have drilled it proved led to a major resource boom with As well as the big boys (Seven Sisters long ago”. He realised that this basin was fledgling companies vying for land, con- derivatives), there are 'little guys' in Aus- one of the most attractive untested areas cessions and geologists. Onshore was the tralia. Interestingly, a recent 'Big' find was in this world and helped to survey the place to be with wildcat prospecting less made by a relative tiddler in the shoal (see likely than a well-chosen spot because of GEO ExPro Update, 05/2007). Innamincka the remoteness and cost of working in the Petroleum (www.INNAPET.com.au) has a Australian bush. new oil reservoir that should last out the The Cooper Basin underlies the desert century. Even more interesting, this is from region of north-eastern South Australia one of the oldest prospecting areas in and south-west Queensland; an uncon- the centre of Australia's “Dead Heart”, the formity at its upper surface varies in depth Late Carboniferous to Middle Triassic, non- from 970 to 2800m while the base of its marine sedimentary Cooper Basin with deepest trough reaches 4400m below sea level. “There is no oil Geologists began tapping into the structures they had seen in this part of the south of the Equator Great Artesian Basin (1.7 million km2 of desert country in central Australia, span- historical production exceeding 4.6 million ning the Cooper, Eromanga, and Surat m3 of oil (29 MMBO). The basin forms the basins mostly with flat-lying Cretaceous most significant element of Australia’s larg- beds yielding ancient water from wells est onshore oil and gas province. The Tir- and bores), clues coming from early 1920's rawarra Field alone contains 80% of known geological surveys. Reg Sprigg, post-war oil reserves. Assistant Government Geologist in South Indigenous Australians, who gain 1% of Australia, like his contemporaries was INNAPET profits, call this the 'Sunset' coun- sceptical of oil turning up. But he became try - a land of fierce lights and desolate convinced that the best hydrocarbon distances (the Santos gas town of Moomba potential was in the far north-east 'Corner is about 120 km away). The main centre, Country' of the State. 'Innamincka' (from 'Yenie' ours; 'Mincka' ©WAPET/AMPOL ©WAPET/AMPOL Archive or Angus & Robertson Another visionary, an ex-King’s messen- a home or shelter) now has few citizens The Carnarvon Basin in Western Australia show- ger, had criss-crossed Australia by air dur- but was once a major trading centre for ing the Rough Range, site of the first exploration well, which hit flow oil in December 1953 and the ing the war, carrying secret messages. He another commodity, 'pituri', native tobacco, dome-like Giralia-Cardabia structure. had been struck (no pun intended) by the a valued stimulant. t 18 GEO ExPro December 2007 C O U NT R Y R E V IE W What irony that it seemed austere and barren to 19th century explorers: Charles Sturt (after whom one central desert is called) found 20-30 m sandhills in his way instead of his dreamed Inland Sea; Burke and Wills, who typify European ignorance in the face of the Australian land, died because of it. The place epitomises the romance and tragedy of the island continent. Innamincka Dome Australian upstream hotted up in 1954 after that first good show in the Rough Range. SANTOS was floated on 8th Octo- ber 1954 and with Sprigg's help, gained Innamincka-1 drillrig 312,225 km2 in leases covering the Great in the Cooper Basin in Artesian Basin. Aerial photographic survey 1959. © Sprigg Family Archive, Arkaroola, used with permission. in the northeast Cooper Basin proved a major gravity “high” corresponding to a giant “oilfield type” anticline, the Innam- over-riding royalties for exploration rights; incka Dome. Dehli-Taylor won the day. Situated to the NE of Lake Eyre, Innam- By 1957 the Federal government CO2 sequestration incka then was hundreds of miles from the announced a pound-for-pound subsidy for And so the life of the earliest oil field nearest Queensland town — nearly 700 new drilling and was keen to deep test miles by dirt track — and from accom- the Cooper Basin.