Improved Subsurface Imaging and Interpretability Through Broadband Reprocessing of Legacy Seismic Data: Examples from North West Shelf Australia

Abstract

The reprocessing of legacy seismic data can be a time and cost effective means of obtaining an improved image of the subsurface, particularly when compared to the acquisition of new seismic data. The investment that has been made over the years in acquiring the many thousands of kilometres of seismic data offshore Australia has been preserved by Geoscience Australia, which houses an extensive collection of petroleum data including seismic survey data. Much of this data is available to the petroleum industry for reprocessing, facilitating the potential to enhance the data’s value for regional reconnaissance and interpretation.

Two marine examples are shown from North West Shelf Australia where reprocessing was performed on seismic data from two different surveys acquired in 1993. The first example is from the Northern Carnarvon Basin, and the second example is from the Browse Basin.

These two examples demonstrate how the uplift attained from a modern broadband processing flow can yield a vastly improved subsurface image, which in turn can assist with interpretation. The reprocessing workflow (which was similar for both surveys) is discussed, as well as some insights into how the improved data benefit the interpretation and understanding of subsurface geology.