Mintabie Opal mining town and the exploration history of shale oil at Officer Basin
Petroleum exploration began in the 1960s, initially by Exoil, Conoco and Outback Oil. Seismic, aeromagnetic and gravity surveys were carried out and seven stratigraphic and two exploration wells drilled. Minor hydrocarbon shows were encountered in Denman 1 on the southern Murnaroo Platform.
Sporadic exploration was continued by the Mines and Energy department until 1979 when the Byilkaoora 1 stratigraphic well intersected significant oil bleeds in the Observatory Hill Formation. Stimulated by this discovery, Comalco carried out extensive mineral and petroleum exploration from 1980–89, including over 2500 km of seismic (mainly weight-drop, Fig. 1), five exploration wells and 20 deep mineral holes. Drillholes were extensively cored and most had wireline logs, though of poor quality.
Comalco exploration significantly improved understanding of the geology and petroleum potential of the NE Officer Basin. Amoco briefly explored an adjacent area in the mid 1980s, acquiring 235 km of 2D Vibroseis data and tying Munyarai 1 to Ungoolya 1. In 1993 AGSO recorded a 550 km transect (explosive source) across the Murnaroo Platform and Birksgate Sub-basin. In the same year, the Mines and Energy department recorded 378 km of Vibroseis in the Marla area.
Hemley Exploration, operator of PELs 61 and 63 in the Marla Overthrust Zone, carried out a detailed aeromagnetic investigation in 1998. This new aeromagnetic data was meshed in with previous aeromagnetic and seismic data and interpreted by Leigh Rankin.
Canadian explorer Rodinia Oil Corp, through an affiliate, Officer Basin Energy Pty Ltd, was granted two PELs in the Officer Basin in July 2007 after successfully concluding a conjunctive access agreement with the traditional Aboriginal owners of Maralinga Tjarutja Lands (Officer Basin Energy became Rodinia Oil Corp. in 2008). The company recorded 985 line-km of seismic in late 2007 and early 2008 (Phase I seismic program), then followed up with 526 line-km of exploration seismic in early 2009 (Phase II). Between November 2010 and June 2011 Rodinia acquired an additional 41 lines of seismic data totalling 2536 line km in PELs 81 and 253.
In June 2011 Rodinia spudded its first oil exploration well in PEL 253 (near the SA-WA border) and drilled to a depth of ~2700m intersecting five prospective formations. Rodinia has stated that the well, Mulyawara 1, confirmed the presence of excellent reservoir quality rocks in the Neoproterozoic succession and provided evidence of a petroleum system. A second well, Kutjara 1, was also drilled in Q4 2011. Rodinia Oil Corp. currently holds two PELs (PELs 81 and 253) and three PELAs (303, 351 and 445) in the Officer Basin.
Rodinia Oil is now in liquidation and the licence assets may be sold in the near future.
PELA 139 (now PELs 499 and 500) was granted in April 2007 to Dawnpark Holdings Pty Ltd and Standard Oil Pty Ltd. The companies were then operators of seven PELAs in the Officer Basin, and planned to negotiate access with the traditional Aboriginal owners of Anangu Pitjantjatjara Yankunytjatjara and Maralinga Tjarutja lands in 2007–08.
Ahava Energy Pty Ltd (Ahava) farmed in to the Standard–Dawnpark licences in 2008 and commenced exploration in the Officer Basin with a 1300 line-km seismic program in early 2009. Ahava acquired an additional 362 line-km of seismic data in late 2009 and drilled three petroleum exploration wells (Welbourn Alpha 1 – PEL 499, Trainor Echo 1 – PEL 138 and Trainor Alpha 1 – PEL 138) in 2010.
In 2011 Ahava acquired a small seismic survey comprising 7 lines for a total 85 line km in PEL 499 and in 2012 drilled a petroleum exploration well (Adi 1) near the southern boundary of PEL 143.
PELAs 147 and 148 were granted to Ahava in July 2011. Ahava (and subsidiary companies) now holds six PELs (138, 143, 147, 148, 499, 500) and 13 PELAs in the Officer Basin.
Ahava are now actively seeking farmin partners to progress exploration of these permits.
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