title: Novel maturity parameters for mature to over-mature source rocks and oils based on the distribution of phenanthrene series compounds.
abstract: Pyrolysis experiments of a low-mature bitumen sample originated from Cambrian was conducted in gold capsules. Abundance and distribution of phenanthrene series compounds in pyrolysis products were measured by GC-MS to investigate their changes with thermal maturity. Several maturity parameters based on the distribution of phenanthrene series compounds have been discussed. The results indicate that the distribution changes of phenanthrene series compounds are complex, and cannot be explained by individual reaction process during thermal evolution. The dealkylation cannot explain the increase of phenanthrene within the EasyRo range of 0.9% ∼ 2.1%. Adding of phenanthrene into maturity parameters based on the methylphenanthrene isomerization is unreasonable, even though MPI 1 and MPI 2 could be used to some extent. Two additional novel and an optimized maturation parameters based on the distribution of phenanthrene series compounds are proposed and their relationships to EasyRo% (x) are established: log(MPs/P) = 0.19x + 0.08 (0.9% < EasyRo% < 2.1%); log(MPs/P) = 0.64x - 0.86 (2.1% < EasyRo% < 3.4%); log(DMPs/TMPs) = 0.71x - 0.55 (0.9% < EasyRo% < 3.4%); log(MTR) = 0.84x - 0.75 (0.9% < EasyRo% < 3.4%). These significant positive correlations are strong argument for using log(MPs/P), log(DMPs/TMPs) and log(MTR) as maturity parameters, especially for mature to over-mature source rocks.
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Zixiang
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Yongli
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Baoxiang
authors.initials: B
authors.lastname: Wu
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Gen
authors.initials: G
authors.lastname: Wang
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Zepeng
authors.initials: Z
authors.lastname: Sun
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Shenzhen
authors.initials: S
authors.lastname: Zhu
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China; University of Chinese Academy of Sciences, Beijing, 100049, China.
authors.forename: Lina
authors.initials: L
authors.lastname: Sun
authors.affiliation: Key Laboratory of Petroleum Resources, Gansu Province/Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
authors.forename: Zhifu
authors.initials: Z
authors.lastname: Wei
keywords: Organic geochemistry; Petroleum geochemistry; Petrology