Hydrocarbon preservation under changing geological conditions

2 Hydrocarbon preservation under changing geological conditions 

Favourable regions for accumulation and entrapment of hydrocarbons are created by the combined influence of buoyancy forces, net driving forces for groimdwater flow and capillary forces. 

Under hydrostatic conditions, the hydrocarbons will become trapped in the reservoir rock when buoyancy-induced lateral upward hydrocarbon migration in the carrier-reservoir rock is stopped by a capillary pressure boimdary. Hydrostatic trapping positions include structural traps, stratigraphic traps and combination traps. The maximum height of a hydrocarbon column that can be contained in a hydrostatic trap is determined by the sealing capacity and geometry of the rocks, or rocks and faults, that form the trap. 

Preservation of trapped hydrocarbons depends on the type of trap, the type of accumulated hydrocarbon and the geological and associated hydrodynamic evolution of the sedimentary basin since entrapment. 

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