Structural style of the White Pointer and Hammerhead Delta—deepwater fold-thrust belts, Bight Basin, Australia
Justin MacDonald A , Rosalind King A , Richard Hillis A and Guillaume Backé AAustralian School of Petroleum
The APPEA Journal 50(1) 487-510 https://doi.org/10.1071/AJ09029
Published: 2010
Abstract
GeoScience Victoria and partners have undertaken the first detailed basin-wide study of the regional top seal in the Gippsland Basin. The Gippsland Basin is an attractive site for geological carbon storage (GCS) because of the close proximity to emission sources and the potential for large-scale storage projects. This top seal assessment involved the analysis of seal attributes (geometry, capacity and mineralogy) and empirical evidence for seal failure (soil gas geochemical anomalies, gas chimneys, hydrocarbon seepage and oil slicks). These datasets have been integrated to produce a qualitative evaluation of the containment potential for GCS, and also hydrocarbons, across the basin. Mineralogical analysis of the top seal has revealed that the Lakes Entrance Formation is principally a smectite-rich claystone. The geometry of the top seal is consistent with deposition in an early post-rift setting where marine sediments filled palaeo-topographic lows. The seal thickness and depth to seal base are greatest in the Central Deep and decrease toward the margins. There is a strong positive relationship between seal capacity column heights, seal thickness, depth to seal base and smectite content. At greater burial depths (below 700 m) and where smectite content is greater than 70%, seal capacity is increased (supportable column heights above 150 m). Natural hydrocarbon leakage and seepage onshore and offshore is correlated with fault distribution and areas of poor seal capacity. This study provides a framework for qualitatively evaluating seal potential at a basin scale. It has shown that the potential of the regional top seal over the Central Deep, Southern Terrace, central eastern Lake Wellington Depression and the southern to central near shore areas in the Seaspray Depression are most suitable for the containment of supercritical CO2. Further toward the margin of the regional seal in both onshore and offshore areas, containment of supercritical CO2 is less likely.
Justin MacDonald is a PhD student at the Australian School of Petroleum. He is a graduate of Memorial University of Newfoundland and the University of Waterloo and holds a BSc (Hons) and a MSc. Justin recently completed his MSc, which involved structural analyses of the Mackenzie Mountains foreland fold and thrust belt in northern Canada. Over the last few years he has worked in base and precious metals exploration in western and northern Canada and for the Northwest Territories Geoscience Office. Justin’s current research interests pertain to structural controls on delta—deepwater fold-thrust belts with particular emphasis on the Ceduna Delta systems of the Bight Basin. Student member: AAPG, PESA, SPE, ASEG and SEG. jmacdonald@asp.adelaide.edu.au |
Rosalind King successfully completed her BSc (Hons) and PhD at the University of Liverpool in 2001 and 2005, respectively. Her PhD research was the Structural Evolution of the Cape Fold Belt, South Africa. Since 2005, she has been working at the Australian School of Petroleum (University of Adelaide) as a post-doctoral researcher. Ros’s current research include the present-day stresses of northwest Borneo and the tectonics of delta—deepwater fold-thrust belts. Ros currently serves as the vice-president of the South Australian Branch of the Petroleum Exploration Society of Australia (PESA). Member: the GSL, AAPG and PESA. rking@asp.adelaide.edu.au |
Richard Hillis is CEO of the Deep Exploration Technologies CRC. He graduated with a BSc (Hons) from Imperial College (London, 1985), and a PhD from the University of Edinburgh (1989) and was until recently State of South Australia Professor of Petroleum Geology and Head of the Australian School of Petroleum (University of Adelaide). He has published over 100 papers in the areas of petroleum geomechanics and basin tectonics and has consulted extensively to, and run short courses for, the petroleum industry on these topics. Richard is a non-executive director of JRS Petroleum Research (privately owned image log and geomechanics consultancy), Petratherm (ASX-listed geothermal company) and AuScope (national research facility in the earth sciences). Member: AAPG, AGU, ASEG, EAGE, GSA, GSL, PESA, SEG and SPE. rhillisdetcrc@gmail.com |
Guillaume Backé recently joined the Australian School of Petroleum, following a two year post doctoral research position at the Centre for Mineral Exploration Under Cover (CMXUC) of the University of Adelaide. He obtained his Master of Geophysics at the University of Toulouse III in France in June 2002, and completed his PhD at the University of Pau et des Pays de l’Adour in December 2006 with a dissertation on the tectonic evolution of the Venezuelan Andes (Venezuela), the Southern Central Andes and the Neuquén basin (Argentina). Guillaume’s main research interests lie in the integration of geophysics and geology for the construction of accurate and validated three-dimensional models of the Earth’s sub-surface, in particular for petroleum, geothermal or geological storage of carbon dioxide applications. Member: AGU, GSA. Active committee member: PESA. guillaume.backe@adelaide.edu.au |
