Changes

* Biodegradation occurs most rapidly in oil [[accumulation]]s exposed to active meteoric water circulation because the water supplies the oxidants or nutrients.

* Biodegradation occurs most rapidly in oil [[accumulation]]s exposed to active meteoric water circulation because the water supplies the oxidants or nutrients.

* Because biodegradation apparently does not significantly affect asphaltenes and many high-molecular-weight aromatics, severe biodegradation does not destroy the oil entirely.

* Because biodegradation apparently does not significantly affect [[asphaltenes]] and many high-molecular-weight aromatics, severe biodegradation does not destroy the oil entirely.

* For aromatic oils, biodegradation results in loss of only 10–20% of the mass of the oil.<ref name=ch11r14>Horstad, I., S. Larter, and N. Mills, 1992, A quantitative model of biological petroleum degradation within the Brent Group reservoir in the Gullfaks field, Norwegian North Sea: Organic Geochemistry, vol. 19, nos. 1–3, p. 107–117., 10., 1016/0146-6380(92)90030-2</ref>

* For aromatic oils, biodegradation results in loss of only 10–20% of the mass of the oil.<ref name=ch11r14>Horstad, I., S. Larter, and N. Mills, 1992, A quantitative model of biological petroleum degradation within the Brent Group reservoir in the Gullfaks field, Norwegian North Sea: Organic Geochemistry, vol. 19, nos. 1–3, p. 107–117., 10., 1016/0146-6380(92)90030-2</ref>

* Because many oils have a high fraction of saturate molecules<ref name=ch11r34 /> it is possible that over 50% of the mass of the oil and gas may be removed.

* Because many oils have a high fraction of saturate molecules<ref name=ch11r34 /> it is possible that over 50% of the mass of the oil and gas may be removed.