The 5 Steps to Heaven, which are source, migration, reservoir, seal and trap, is one of the most important concepts of petroleum geology. This tells us how petroleum was formed, migrated and trapped in a reservoir. Please note that the 5 Steps to Heaven is valid for conventional petroleum resources.
Typically, organic matter from animals and plants is oxidized and turned an organic matter into carbon dioxide and water. However, if organic matter is buried rapidly, it may be preserved and can be turned into petroleum. These following conditions enhance organic matter preservation.
- High sedimentation rate
- Fine grain size so oxygen will not be able to penetrate and oxidize the organic matter
- Anoxic bottom water
These conditions are mostly found in shale and fine limestone, which are common source rocks. Continue reading