Summary
Many frontier basins have widely spaced, vintage 2D seismic data available. The often poor quality of this vintage seismic makes it difficult to derive any meaningful geological information. By using additional complementary datasets, interpretation of the seismic data is often possible. Here we show how FALCON® Airborne Gravity Gradiometer (AGG) data combined with magnetic and other geological data has enabled a geological model to be constructed and vintage seismic to be interpreted. A workflow involving integrated interpretation of AGG, magnetic and seismic data is described using an example from the Canning Basin in northern Western Australia.
Introduction
The Canning Basin in northern Western Australia is an under explored frontier basin. Available data is generally restricted to vintage 2D seismic, few wells and regional magnetic and gravity data. The Buru Energy Joint Venture conducted a FALCON® Airborne Gravity Gradiometer survey over the southern margin of the Fitzroy Trough covering parts of the Jurgarra, Mowla and Barbwire Terraces and the Broome and Crossland Platforms (Figure 1). The survey covered almost 40,000 km2 with 1,000 m spaced north/south lines. The main objective of the survey was to understand the 3D geology of the survey area to assist in the planning of further 2D and 3D seismic surveys.
All available vintage data has been combined with the newly acquired AGG and magnetic data to produce an integrated interpretation. After an initial integrated structural interpretation, reinterpretation of selected seismic traverses and subsequent 2.5D gravity modelling was completed. These modelled traverses were then used to produce a 3D geological model of the northern part of the survey area.
Integrated Interpretation Method
Integrated interpretation of all available complementary datasets enables the construction of robust geological models. The workflow described here is an iterative approach and prior steps are reviewed at the completion of subsequent steps. The integrated approach is as follows:
