New play type, southern Bonaparte Basin-Petrel Sub-basin—WA-442-P and NT/P81 exploration permits
Margaret Hildick-PytteTangiers Petroleum
The APPEA Journal 52(1) 525-544 https://doi.org/10.1071/AJ11041
Published: 2012
Abstract
Recent investigation, including mapping re-processed seismic data, suggests there is deeper hydrocarbon potential in the WA-442-P and NT/P81 exploration permits beneath the Early Carboniferous Tanmurra Formation horizon. Earlier interpretation of the area showed tilted fault blocks commonly thought of as economic basement in the vicinity of the Turtle and Barnett oil fields and extending to the northwest to connect with the Berkley Platform. The deep-gas play type is structural and is believed to be two nested three-way dip anticlines developed against a large bounding fault to the northeast, with axial trends northwest to southeast, and axial plane curving towards the northeast for the deeper structure. This play type is believed to be associated with structural compression and movement along the master fault with incremental re-activation most recently during the Cainozoic as recorded in overlying sediments.
The Nova Structure and the deeper Super Nova structure have closures of about 450 and 550 km2, respectively. The sediments beneath the Nova horizon are believed to be of Devonian Frasnian-Famennian age but have not been drilled offshore in the Southern Bonaparte Basin (Petrel Sub-basin). Earlier work suggests that there are two petroleum systems present in the southern Bonaparte Basin, a Larapintine source from Early Palaeozoic Devonian to Lower Carboniferous source rocks, and a transitional Larapintine/Gondwana system sourced from Lower Carboniferous to Permian source rocks. Hydrocarbon charge for the structures is most likely from the Larapintine source rock intervals or yet to be identified older intervals associated with the salt deposition during the Ordovician and Silurian. Independent estimates place close to 7 TCF (trillion cubic feet) of gas in the Nova Structure. New 3D seismic data acquisition is planned over the structures to better define the geology and ultimately delineate well locations.
Margaret Hildick-Pytte is the director of exploration for Tangiers Petroleum Limited. She graduated from the University of Vermont in 1977, with a BSc Honours in Geology. Margaret was awarded a MSc in Geology, in 1982, from Auburn University, in the US She is presently studying petroleum engineering at UNSW. Margaret worked for the Gulf Oil Company in the US, the Chevron Oil Company in the US and internationally, Advanced Well Technology International, and INPEX Browse. She has worked in various areas including oil and gas exploration, well-site and development geology, coalbed methane gas exploration and development, CO2 geosequestration, organic geochemistry, and applied research. Margaret holds a Fellowship in the London Geological Society and the Australian Gemmological Society, and is a Founding Member of the AAPG affiliated Society for Organic Petrology. Member: AAPG, SPE, PESA, FESAUS, and SPWLA. mhpy@tangierspetroleum.com.au |
