Petroleum systems, or Total Petroleum Systems (TPS) as defined by the U.S. Geological Survey, are the "essential elements and processes needed for oil and gas accumulations to exist." These include the essential elements, which are the petroleum source, oil or natural gas reservoirs, seal and active source rock. This system also includes the process by which these sources have been generated, migrated, trapped, or otherwise accumulated and the "genetically related petroleum."
This term was first used in 1980. Since then work has been done to identify, map and name petroleum systems across the world to increase access to petroleum reserves. This identification is done using geology and geochemistry. To discover oil and gas fields with a given petroleum system investigators begin with a map of the discovered oil and gas fields in the area. Then using this and other information about the petroleum system the investigator groups these fields together based off geographic, geologic, geochemical and fluid characteristics.
- Active rocks are contiguous rock formations that expelled petroleum at just the right time. These pods of active rocks are also known as kitchens or oil and gas windows.
- U.S. Geological Survey, "The Total Petroleum System--The Natural Fluid Network That Constrains the Assessment Unit," 2000
- Oilfield Review, "Basin to Basin: Plate Tectonics in Exploration," Autumn 2012
- Schlumberger, "Oilfield Glossary," accessed April 27, 2014