Exploration assessment in a petroleum frontier area offshore the Amazon River mouth using RADARSAT-1 images

The study discusses the use of RADARSAT-1 images to identify oil seepage in the Foz do Amazonas Basin, an oil and gas exploration frontier in the Brazilian Equatorial margin. An unsupervised semivariogram textural classifier algorithm was used to enhance areas of smooth texture and low radar backscatter, indicative of these targets. Complementary information related to cloud top temperature, wind velocity, and modelling for the tidal regime (all obtained as close as possible to the RADARSAT-1 images acquisition) was used to support image interpretation and to exclude false-targets. Together with previously discovered sub-commercial shallow water oil accumulations, the detection of seepage slicks an additional evidence of oil generation in the study area. Results also indicate that radar remote sensing can be used as a tool to reduce risks in the exploration of frontier areas like the Foz do Amazonas Basin