Geochemical characteristics and source rock of Ordovician gas reservoir, Changqing Gasfield  

Geochemical characteristics and source rock of Ordovician gas reservoir, Changqing Gasfleld

作　　者：XIA Xinyu, ZHAO Lin, ZHANG Wenzheng and LI JianfengResearch Institute of Petroleum Exploration and Development, Beijing 100083, China Changqing Petroleum Exploration Bureau, XL an 710021 , China 

出　　处：《Chinese Science Bulletin》1999年第20期1917-1920,共4页

摘　　要：Carbon isotopic composition of methane in Ordovician gas reservoir in the Changqing Gasfield can reflect the dominance of Upper Paleozoic coal-type gas despite its high mature degree. The 12C-rich ethane in the Ordovician reservoir (δ13C2 【 - 29‰), known as a marker as oil-type gas, does not indicate the Ordovician marine carbonate as main source rock, it is be-Carbon isotopic composition of methane in Ordovician gas reservoir in the Changqing Gasfield can reflect the dominance of Upper Paleozoic coal-type gas despite its high mature degree. The 12C-rich ethane in the Ordovician reservoir (δ13C2 < - 29‰), known as a marker as oil-type gas, does not indicate the Ordovician marine carbonate as main source rock, it is because of the relative less ethane content in coal-type gas than in oil-typed gas due to generation and migration. The way of Upper Paleozoic coal-type gas migrating into the Ordovician reservoir is widely through the unconformity instead of only through the erosion groove in the weathering crust.

关 键 词：methane ETHANE carbon ISOTOPE natural gas genesis. CHANGQING Gasfield. 

分 类 号：P534.42[天文地球—古生物学与地层学]