hydrokarbontraps

Hydrocarbon traps are geological structures that accumulate hydrocarbons—oil and natural gas—in subsurface reservoirs. They form when porous rocks containing hydrocarbons are overlain or surrounded by impermeable rocks that act as a seal, preventing upward or lateral migration.

There are structural traps, created by tectonic deformation. Anticlines and fault traps are common structural forms. Salt domes and structural lows overlain by cap rocks can also form traps. Stratigraphic traps arise from variations in rock type or geometry, such as pinch-outs, reefal barriers, or unconformities, which create a reservoir with a seal locally.

Formation requires three elements: source rocks generating hydrocarbons, migration pathways moving hydrocarbons into a reservoir, and a seal that maintains accumulation. The timing between generation, migration, and trap formation influences the size and quality of the accumulation. Leakage and seal breach reduce trap effectiveness.

In exploration, hydrocarbon traps are identified through seismic surveys, gravity and magnetic data, and well logs. Reservoir properties (porosity, permeability) and cap rock integrity are evaluated to estimate volumes and risk.

Hydrocarbon traps underpin global oil and gas resources and are a central concept in petroleum geology and exploration. They are dynamic; changes in stress, sealing capacity, or migration can modify trap effectiveness over geological time.