Tailored acquisition and processing providing an enhanced subsurface image of the basin architecture, Exmouth Sub-basin, North West Shelf, Australia
Alexander Karvelas A D , Bee Jik Lim A , Lianping Zhang A , Haryo Trihutomo A , Oliver Schenk B and Sugandha Tewari CA Schlumberger, Level 5, 256 St Georges Terrace, Perth, WA 6000, Australia.
B Schlumberger GmbH, Ritterstr. 23, 52072 Aachen, Germany.
C Schlumberger House, Gatwick, West Sussex, RH6 0NZ, UK.
D Corresponding author. Email: AKarvelas@slb.com
The APPEA Journal 59(2) 886-890 https://doi.org/10.1071/AJ18155
Accepted: 30 November 2018 Published: 17 June 2019
Abstract
Hydrocarbon exploration has resulted in the discovery of a variety of oil and gas accumulations mainly in Upper Jurassic and Lower Cretaceous intervals. However, the distribution of the different petroleum system elements including Jurassic and Triassic intervals is poorly determined, but required for improved understanding of the complex charge history, as indicated by the variety of hydrocarbon types encountered in the basin.
The new WesternGeco multiclient 3D seismic survey extends to the edges of the basin to give a comprehensive picture. Raw hydrophone data were delivered from the vessel as acquisition progressed to begin the near-surface model building. The model building consisted of two major stages: first, using full waveform inversion (FWI) to derive the near-surface velocity field; and, second, common image point (CIP) tomography to update the deeper section beyond the FWI illumination zone.
As illustrated herein, various stages of processing and imaging provided a cleaner and crisper dataset across the record length, allowing (1) detailed picking of the events within the entire Mesozoic (Cretaceous–Triassic) section allowing key events to be interpreted and correlated across the area and (2) accurate investigation of the complexity of different aged fault networks and their relationships across the full Exmouth Sub-basin for the first time.
In summary, this survey provides a detailed insight into the deeper basin architecture of the Exmouth Sub-basin. The seamless volume imaged to depth allows accurate mapping which is critical to unravel the complex evolutionary history in a basin with proven and significant remaining hydrocarbon potential.
Keywords: depth imaging, full waveform inversion, interpretation, seismic acquisition, seismic data processing.
Alex Karvelas is the Exploration Lead for the WesternGeco Australasia region based in Perth. His role includes interpretation on depth imaging and reprocessing projects, but also supporting new acquisition projects from survey design, data processing, through to final delivery. In addition to supporting live projects in Australasia, Alex is also actively part of the Exploration and Petroleum Systems Modelling groups which support exploration campaigns and basin hydrocarbon assessment projects around the world. |
Bee Jik Lim is an Area Geophysicist for WesternGeco based in Perth, Australia. She joined WesternGeco in 1999 and moved to Perth in 2010. She has over 18 years of industry experience with an extensive background in seismic data processing and earth model building and imaging throughout various countries in the Asia Pacific region. |
Lianping Zhang is an Earth Modelling Geoscientist for WesternGeco based in Perth, Australia. Lianping joined WesternGeco in 2011, moving to Perth in 2016. Her experience ranges from different depth modelling and imaging projects from across the world with current focus in offshore Australia and New Zealand. |
Haryo Trihutomo has a BSc in Geophysics from University of Gadjah Mada, Indonesia. Haryo joined WesternGeco in 2010 and is currently based in Perth, Australia. He works as Project Manager and has 8 years of industry experience from various countries in the Asia Pacific and Middle East. |
Oliver Schenk is a Petroleum System Modelling Supervisor for WesternGeco based in Aachen, Germany. He has more than 12 years of professional experience dedicated to multi-dimensional applications of petroleum systems modelling in the international petroleum exploration industry covering many key basins around the world. Oliver received his Diploma Degree in Geology from RWTH Aachen University in Germany as well as a PhD in structural geology (2006). |
Sugandha Tewari is a Senior Geoscientist with over 12 years of oil industry experience. Since joining WesternGeco in 2010, she has been involved in various seismic interpretation projects in diverse tectonic settings including the Mannar Basin (Sri Lanka), Gulf of Mexico, South Viking Graben (North Sea), East and West Africa, and more recently in the Asia Pacific region. |
