Offshore petroleum exploration from space: A developing capability at Geoscience Australia

Natural seepage can generate hydrocarbon slicks on the sea surface that may provide petroleum explorers with direct evidence of oil and gas below the sea bed. Remote sensing has the potential to be used as a tool for detecting such sea surface slicks, thereby identifying areas in both producing and frontier basins that are prospective for hydrocarbons. We are developing a two-pronged, remote sensing-based approach for seepage slick studies in the Australian Marine Jurisdiction: 1) building a semiautomated processing and classification system in order to scan large numbers of Synthetic Aperture Radar scenes for potential natural slick targets, and; 2) investigating the potential of optical remote sensing as a diagnostic tool for further, targeted study. Using objected-oriented classification algorithms in a bulk processing environment, large Synthetic Aperture Radar data sets were able to be efficiently screened for potential natural oil slick targets. This processing system offers a range of outputs, including classification statistics for each scene studied, as well as geo-referenced shapefiles ready for analysis in Geographic Information System software, where it can be combined with ancillary data sets for contextual analysis. Our research into the potential for optical remote sensing to enable further diagnostic study of identified, potential targets has shown that there are several commercially available, space borne sensors able to detect the types of oils found throughout the Australian Marine Jurisdiction, but that oil type is critical for this application. Further to this, we have developed an approach for performing a feasibility study of oil type versus sensor sensitivity prior to image data acquisition.