The Latrobe Group and the 90-million-year beach
Nick Hoffman A and Natt Arian B CA Victorian Department of State Development, Business and Innovation (DSDBI).
B CarbonNet.
C Presenter only.
The APPEA Journal 53(2) 460-460 https://doi.org/10.1071/AJ12071
Published: 2013
Abstract
Carbon dioxide geosequestration requires a detailed understanding of the whole sedimentary section, with particular emphasis on topseals and intraformational seals. Hydrocarbon exploration is more focused on reservoirs but requires a similar basin understanding. This extended abstract reviews the knowledge gained from petroleum exploration in the Gippsland Basin to The CarbonNet Project’s exploration program for CO2 storage.
The Ninety Mile Beach on the Gippsland coast is a prominent modern-day sand fairway where longshore drift transports sediments north-eastwards along a barrier-bar system, trapping lake systems behind the coastal strip. This beach is only 10,000 years old (dating to the last glacial rise of sea level) but is built on a platform of earlier beaches that can be traced back almost 90 million years to the initiation of Latrobe Group deposition in the Gippsland Basin.
Using a recently compiled and open-file volume of merged 3D seismic surveys, the authors show the evolution of the Latrobe shoreline can be mapped continuously from the Upper Cretaceous to the present day. Sand fairways accumulate as a barrier-bar system at the edge of a steadily subsiding marine embayment, with distinct retrogradational geometries.
Behind the barrier system, a series of trapped lakes and lagoons are mapped. In these, coal swamps, extensive shales, and tidal sediments were deposited at different stages of the sea-level curve, while fluvial systems prograded through these lowlands. Detailed 3D seismic extractions show the geometry, orientation and extent of coals, sealing shales, fluvial channels, and bayhead deltas.
Detailed understanding of these reservoir and seal systems outlines multi-storey play fairways for hydrocarbon exploration and geosequestration. Use of modern basin resource needs careful coordination of activity and benefits greatly from established data-sharing practices.
Nick has more than 25 years of international oil-industry experience, including substantial time with BP in Europe and with BHP in Australia and worldwide. For much of the past decade, he led 3D-GEO, a private geoscience consulting house, specialising in basin evaluation and reservoir studies. He joined CarbonNet in 2011 as part of the start-up technical team to lead the geoscience evaluation of CarbonNet’s portfolio of nearshore CO2 sequestration targets. He is an expert geophysicist, sequence stratigrapher, and basin geologist with significant experience interpreting depositional environments, structural evolution, and reservoir distribution from 3D and 2D seismic and from well data. |
Natt Arian is managing director of Arian Petroleum Pty Ltd (privately owned petroleum consultancy company based in Melbourne). He is also serving as a senior geoscientist/modelling specialist at the DPI’s CarbonNet Project. He graduated with a Bsc (geology and petroleum engineering) from the University of Saladin, Kurdistan, and obtained his PhD (petroleum engineering and petroleum geosciences) from the Australian School of Petroleum, the University of Adelaide, Australia. He has worked and consulted several Australian and overseas oil companies, and he has specialised in basin and integrated petroleum systems modelling, integrated reservoir modelling, and simulations and basin analysis. Member: PESA, SPE, AAPG. |
