Synthetic Aperture Sonar (SAS) and Autonomous Underwater Vehicles - Essential Tools for Exploration of Hydrocarbon Seeps

Abstract

Natural gas seepages are of great interest for the petroleum industry, both for prospecting and environmental reasons. Gas flares originating from gas seeps can be fairly easily identified by multibeam water column data, but further investigations require observations from close range. ROV investigations provide high detail, but are time consuming and costly. AUVs (autonomous underwater vehicles) have proven to be very useful for such investigations, traditionally carrying sidescan sonars, multibeam echosounders and other equipment. Synthetic aperture sonars are now emerging as a new tool, giving unrivalled resolution. Used in combination with high resolution colour photos, methane sniffers and other sensors, we can now get detailed documentation over large areas within limited time.