| * Economic gas accumulations become more unusual with maturation levels > 2.8% R<sub>o</sub>.<ref name=ch11r3>Bartenstein, H., 1980, Coalification in NW Germany: Erdöl und Kohle-Erdgas-Petrochemie: vol. 33, p. 121–125.</ref> This is the traditional base of the gas preservation zone. | | * Economic gas accumulations become more unusual with maturation levels > 2.8% R<sub>o</sub>.<ref name=ch11r3>Bartenstein, H., 1980, Coalification in NW Germany: Erdöl und Kohle-Erdgas-Petrochemie: vol. 33, p. 121–125.</ref> This is the traditional base of the gas preservation zone. |
− | * The major gas accumulation with the highest well-documented maturity level where charging occurred before or during exposure to the high temperatures occurs at a maturation level 3.5–3.8% R<sub>o</sub> equivalent (Wilburton field, Oklahoma, .<ref name=ch11r13>Hendrick, S., J., 1992, Vitrinite reflectance and deep Arbuckle maturation at Wilburton field, Latimer County, OK: Oklahoma Geological Survey Circular 93, p. 176–184.</ref> | + | * The major gas accumulation with the highest well-documented maturity level where charging occurred before or during exposure to the high temperatures occurs at a maturation level 3.5–3.8% R<sub>o</sub> equivalent (Wilburton field, Oklahoma).<ref name=ch11r13>Hendrick, S., J., 1992, Vitrinite reflectance and deep Arbuckle maturation at Wilburton field, Latimer County, OK: Oklahoma Geological Survey Circular 93, p. 176–184.</ref> |