Light Hydrocarbon (C5-C7) Geochemistry in the Northern Margin of the Qaidam Basin, Northeastern Tibetan Plateau: Gas Mixing and Hydrocarbon Charge History.

ABSTRACT: Twenty natural gases from the northern margin of the Qaidam Basin were collected and examined for the composition and stable carbon isotopic characteristics of gas and light hydrocarbons (C5-C7). The results reveal that the carbon isotopes of iso-alkanes and cyclo-alkanes in light hydrocarbons are mainly controlled by the bioprecursors, whereas the carbon isotopes of n-alkanes and aromatics in light hydrocarbons are primarily influenced by the bioprecursors and maturity. Based on the genetic types obtained from C1-C3 and C5-C7 fractions, three types of gases are identified: coal-type gas, oil-type gas, and mixed gas. Coal-type gas dominates the northern margin of the Qaidam Basin, oil-type gas is mostly distributed in the Lenghu no. 3 field, and mixed gas is mainly developed in the Dongpin

SUBMITTER: Chen K 

PROVIDER: S-EPMC8655948 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature