Origin Determination of Gas from Jingbian Gas Field in Ordos Basin Collective Through the Geochemistry of Gas from Inclusions and Source Rock Pyrolysis

详细信息   

• 责任者：Mi JingKui(Research Institute of Petroleum Exploration and Development ; PetroChina ; Beijing 100083 ; China) ; Wang XiaoMei
• 刊名：Acta Petrologica Sinica
• 出版年：2012
• 卷期：28(3)
• 页码：p.859-869
• issnNo：ISSN1000-0569
• isbnNo：CN11-1922/P

摘要

The geochemistry comparison of the gas from inclusions and that of pool gas show that the geochemistry of pool gas found in Upper-Paleozoic formation is similar with that of the gas from inclusion. So, the pool gas may equal the original gas found in upper-Paleozoic formation in Ordos basin. There is great difference of geochemistry between the gas from inclusions and the gas from Lower-Paleozoic gas pool. The geochemistry of Lower-Paleozoic pool gas is also different to that of the gas produced by source rock pyrolysis. So, the Lower-Paleozoic pool gas could not reveal the original gas when the gas pool formation. The gas which come from Lower-Paleozoic source rock in Ordos basin have a characteristics with δ¹³C₁<-38‰, δ¹³C₂<-28‰ by

    

comparing the geochemistry of the gases from inclusions, the gases from Lower-Paleozoic source rock pyrolysis and the gases from Jingbian gas field. The analysis to geochemistry of gas from inclusion and that from Lower-Paleozoic gas pools suggest that shift range of δ¹³C₂ is wider than that of δ¹³C₁. So, the authors suggest

    

that the δ¹³C₂ is improper as a criterion judging the Lower-Paleozoic gas origin. δ¹³C₁ average of methane

    

(δ¹³C₁=-32.90‰) from Uupper-Paleozoic gas pools and the δ¹³C₁ average (δ¹³C₁=-39.04‰)of Lower-Paleozoic gas with δ¹³C₁<-38‰ should be consider as the indexes of the gases originated from Upper and

    

Lower-Paleozoic source rock, respectively. Ultimately, the authors concluded that about 85% gas in Jingbian gas field come from Upper Paleozoic coal-bearing source rock.