Abstract
A GIS hazard map was created using geological settings, because they control local formation of biogenic gas, which is the most common gas (as defined by origin) in shallow sediments. The highest probability of shallow gas occurrence is in shallow marine settings with high terrestrial influx, deltas in particular. Therefore, a delta classification system based on shallow gas hazard was created and was verified using known gas occurrences. Together the hazard map and delta classification system can be an early screening tool for shallow gas hazard to provide input for risk assessments regarding open-hole or riser-less offshore drilling operations, even when no other relevant data are available.