Changes

==Concentration of traps==

==Concentration of traps==

In many regional pressure compartments, hydrocarbon generation creates pressures great enough to fracture the top seal. Top-seal fracturing episodically releases pressure and fluids, including oil and gas, from the pressure compartment. Oil and gas tend to be trapped in the first reservoir-quality rock over leak points.<ref name=ch05r12 /> Leak points form where the top seal is shallowest because fracture pressure is lowest in the top seal at that point. Leak points also can occur where faults are reactivated during tectonic events.<ref name=ch05r7>Gaarenstroom, L., Tromp, R., A., J., de Jong, M., C., Brandenburg, A., M., 1993, Overpressures in the Central North Sea: implications for trap integrity and drilling safety, in Parker, J., R., ed., Petroleum Geology of Northwest Europe: Proceedings of the Geological Society's 4th conference, London, p. 1305–1313.</ref>

In many regional pressure compartments, hydrocarbon generation creates pressures great enough to fracture the top seal. Top-seal fracturing episodically releases pressure and fluids, including oil and gas, from the pressure compartment. Oil and gas tend to be trapped in the first reservoir-quality rock over leak points.<ref name=ch05r12 /> Leak points form where the top seal is shallowest because fracture pressure is lowest in the top seal at that point. Leak points also can occur where faults are reactivated during tectonic events.<ref name=ch05r7>Gaarenstroom, L., R. A. J. Tromp, M. C. de Jong, and A. M. Brandenburg, 1993, Overpressures in the Central North Sea: implications for trap integrity and drilling safety, in J. R. Parker, ed., Petroleum Geology of Northwest Europe: Proceedings of the Geological Society's 4th conference, London, p. 1305–1313.</ref>

==Compartment-associated traps==

==Compartment-associated traps==