Changes

==Expulsion percentage ranges==

==Expulsion percentage ranges==

[[file:migration-of-petroleum_fig7-13.png|left|thumb|{{figure number|1}}After Magara.<ref name=ch07r5>Magara, K., 1980, Evidences of primary migration: AAPG Bulletin, vol. 64, p. 2108–2117.</ref>]]

[[file:migration-of-petroleum_fig7-13.png|left|thumb|{{figure number|1}}After Magara.<ref name=ch07r5>Magara, K., 1980, [http://archives.datapages.com/data/bulletns/1980-81/data/pg/0064/0012/2100/2108.htm Evidences of primary migration]: AAPG Bulletin, vol. 64, p. 2108–2117.</ref>]]

Typical oil expulsion efficiencies are estimated to be in the 5-10% range, with values in the 15% range uncommon and 30% rarely demonstrated. This efficiency is low because most of the source rock section contains too low a concentration of organic material to participate in the expulsion process. Efficiencies of gas expulsion are estimated to be 50-90%, with values of 75% common. Unfortunately, much of this is gas lost due to solution and does not participate in reservoir charging. For both oil and gas, expulsion efficiencies tend to increase with increasing TOC. Expulsion efficiencies for oil and gas can be as high as 70-80% for very rich, effective [[source rocks]] near preferential [[migration pathways]].

Typical oil expulsion efficiencies are estimated to be in the 5-10% range, with values in the 15% range uncommon and 30% rarely demonstrated. This efficiency is low because most of the source rock section contains too low a concentration of organic material to participate in the expulsion process. Efficiencies of gas expulsion are estimated to be 50-90%, with values of 75% common. Unfortunately, much of this is gas lost due to solution and does not participate in reservoir charging. For both oil and gas, expulsion efficiencies tend to increase with increasing TOC. Expulsion efficiencies for oil and gas can be as high as 70-80% for very rich, effective [[source rocks]] near preferential [[migration pathways]].