Seals are fundamental; no seal, no trap. Seals, or their absence, also define leak points that control the percent fill for hydrocarbon accumulations. Assessment of percent fill without the ability to risk seal (top or fault) is reduced to a statistical guessing game. They control the vertical and lateral distribution of hydrocarbons, both within individual fields and within basins. | Seals are fundamental; no seal, no trap. Seals, or their absence, also define leak points that control the percent fill for hydrocarbon accumulations. Assessment of percent fill without the ability to risk seal (top or fault) is reduced to a statistical guessing game. They control the vertical and lateral distribution of hydrocarbons, both within individual fields and within basins. |